Dissertations / Theses on the topic 'Pathology Histology'

Introduction: During the last decade, our institution saw a 260% increase in bilateral breast reconstruction cases, consistent with national trends. We reported a drop in average age of prophylactic mastectomy from 57 to 51 years. There is limited data on the likelihood of histological abnormalities in this population. This study measures the prevalence of occult histological findings in prophylactic mastectomy patients. Given the current healthcare reform climate, we estimate the lifetime cost implications of prophylactic mastectomy with immediate reconstruction vs. surveillance. Methods: A retrospective database of breast reconstructions at the Massachusetts General Hospital was searched from 2004 to 2011 for prophylactic mastectomy patients. Breasts with prior biopsy-proven LCIS, DCIS, or cancer were excluded. Patient demographics, risk factors, and pathology reports were collected. Lifetime treatment reimbursements were estimated with 2013 rates from the Center for Medicare and Medicaid Services using Medicare billing codes. Reimbursements were estimated for 45-year-old patients undergoing contralateral prophylactic mastectomy and 40-year-old patients undergoing bilateral prophylactic mastectomies, and then were compared to women opting for surveillance. Conversion rates to cancer in these patients were used to estimate the percentage patients in the surveillance groups that would need therapeutic mastectomy. Sensitivity analyses were done to test the robustness of the models. Results: 495 prophylactic mastectomy specimens were identified, of which 2.0% had invasive cancer, 4.4% had ductal carcinoma in situ (DCIS), and 10.9% had lobular carcinoma in situ (LCIS) as the highest-risk lesion. Only age group was predictive of finding DCIS or cancer (P=0.02). The likelihood of finding LCIS, DCIS, or cancer increased with age group (P<0.001) and decreased with prior bilateral salpingo-oophorectomy (BSO)(P=0.02). In almost all scenarios, lifetime reimbursements were lower for pursuing either contralateral or bilateral prophylactic mastectomy, with immediate single-stage implant, expander, or abdominal perforator free flap (DIEP) reconstruction, as compared to surveillance. Conclusions: Prophylactic mastectomy patients have a significant rate of occult histological findings, increasing with age group and decreasing with prior BSO. Lifetime cost estimates suggest a cost-saving role in bilateral and contralateral prophylactic mastectomies. Ultimately, such a critical decision needs to be made individually, but should not be hindered by cost concerns. This study addresses a gap in knowledge with broad interest, contributing evidence of oncologic risk and cost to help guide decision-making in prophylactic mastectomy.

Geology
M.S.
In modern organisms the structure and arrangement of bone apatite crystals is dependent on the arrangement of the organic collagen fibers. This is reflected in the formation of different types of bone tissue, such as woven (immature) or lamellar (mature), in pathological versus normal bone, or fast-growing (woven) versus slow-growing (lamellar) tissue. Because the basic physiological processes of fracture healing are similar in extant vertebrates, similar patterns may exist in fossil taxa. The three questions of interest for this study were the following: 1) Do differences exist in modern bone apatite crystallinity between normal and pathologic bone? 2) Are differences between normal and pathologic tissue consistent in both modern and fossil bone? 3) Does the type of bone tissue affect fossilization? In this study, we use histological and x-ray diffraction (XRD) analyses to examine fracture pathologies in pedal phalanges from the theropod dinosaur Allosaurus fragilis, and two modern bird species, Branta canadensis (Canada goose) and Cathartes aura (turkey vulture). Raman spectroscopy analysis was performed on modern birds, but not fossil material. Stable isotope and rare earth elements (REE) analyses were performed on fossil material to determine if there are differences in how pathologic bone fossilizes compared to normal bone. Results from Raman spectroscopy and XRD confirm that pathologic bone is more crystalline than normal bone in both fossil and modern taxa. Stable isotope and REE analyses do not show any difference in fossilization between pathologic and normal bone, suggesting that these techniques are more suitable for examining taphonomic rather than physiological differences.
Temple University--Theses

Thesis (PhD)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Tuberculosis (TB) is a chronic pulmonary infection characterized by granulomatous inflammation, caseating necrosis and a propensity to develop fibrosis and cavitations. Pulmonary TB (PTB) lesions may develop in a variety of ways and can be grouped into primary, secondary, progressive primary and miliary TB based on their pathogenesis and morphological appearance. The Western Cape Province, South Africa, has a high TB burden with increasing TB notification rates. At Stellenbosch University (SU), approximately 90% of cadavers used for medical dissections come from impoverished communities where TB is a major health problem in terms of morbidity. The aim of the present study was to assess the health status of a cadaver population (n=127) at the Faculty of Medicine and Health Sciences (FMHS), SU, with special reference to TB lesion distribution and prevalence. For this study, full-body digital X-rays of 127 cadavers (87 males; 40 females; average age, 47.1 years) were obtained with the Lodox® Statscan® Imaging System after embalming and prior to dissection. A complete pathology report of six organ systems including the skeletal system was used in combination with histological examination, molecular analysis and radiological findings to investigate the prevalence and association between TB and systemic pathology. Samples for histological purposes were removed from organs with pathology lesions. For molecular studies, five different nucleic acid extraction methods were used to extract DNA from the formalin-fixed paraffin-embedded cadaver samples. Pulmonary samples were subjected to a line probe assay (LPA) and polymerase chain reactions (PCR) to determine mycobacterial genotypic distribution. Two independent radiologists examined the chest X-rays and their findings were compared with the pulmonary findings. PTB was a common finding in the cadaver population (76.4%) with males more commonly affected. A female predilection was observed for extrapulmonary TB. Statistically, TB was associated with pulmonary pathology, including pneumonia and bronchiectasis. Systemic pathology commonly encountered in the present study included neoplasms, coronary artery disease, colonic diverticula, hepatic triaditis, cirrhosis, glomerulosclerosis, pyelonephritis and a variety of healed maxillofacial and appendicular skeletal fractures. Extracted nucleic acid concentrations, as determined with the NanoDrop® spectrophotometer, ranged between 10ng/μl and 1000ng/μl. The standard salting-out method was found to be the most cost-effective and therefore the preferred method for nucleic acid extraction. The HAIN® MTBDRplus® kit was effective in determining the presence of mycobacterial species belonging to the Mycobacterium tuberculosis complex (MTBC). The sensitivity to first-line drugs could not be determined as a result of DNA degradation. Spoligotyping was unsuccessful, as incomplete and unidentifiable hybridization of the 43 spacers occurred. The RD105 and MUB02/RD105 PCR results were non-reproducible and non-specific. Pulmonary cavitation and pleural thickening were the only findings that were positively correlated with the radiological findings (p<0.05). To our knowledge, this is the first study to extensively investigate TB and systemic pathology including histopathology, molecular techniques and postmortem radiology in cadavers from low socio-economic backgrounds from a high TB burden area. This study therefore provides a more complete and thorough understanding of the prevalence, distribution and morphology of TB lesions as well as the association between TB and systemic pathology.
AFRIKAANSE OPSOMMING: Tuberkulose (TB) is a kroniese, pulmonêre infeksie gekenmerk deur granulomateuse ontsteking, verkasende nekrose en ’n neiging om fibrose en kavitasies te ontwikkel. Pulmonêre TB (PTB) letsels kan op verskeie wyses ontwikkel en kan, gebaseer op patogenese en morfologiese voorkoms, geklassifiseer word as primêre, sekondêre, progressiewe primêre of miliêre TB. Die Wes-Kaap provinsie, Suid-Afrika, het ’n hoë TB las met toenemende TB aanmeldingskoerse. Ongeveer 90% van die kadawers wat by die Universiteit Stellenbosch (US) gebruik word vir mediese disseksies kom van verarmde gemeenskappe waar TB ’n groot gesondheidsprobleem is in terme van die siektesyfer. Die doel van hierdie studie was om die gesondheidstoestand te bepaal van ’n kadawerpopulasie (n=127) by die Fakulteit Geneeskunde en Gesondheidswetenskappe (FGG), US, met spesifieke verwysing na die verspreiding en voorkoms van TB letsels. Digitale X-strale van die hele liggaam van 127 kadawers (87 manlik; 40 vroulik; gemiddelde ouderdom, 47.1 jaar) na balseming en voor disseksie is met behulp van die Lodox® Statscan® Imaging System bekom. ’n Volledige patologie-verslag van ses orgaanstelsels, die skeletstelsel ingesluit, is in kombinasie met histologiese ondersoeke, molekulêre ontleding en radiologiese bevindinge gebruik om die voorkoms van en assosiasie tussen TB en sistemiese patologie te ondersoek. Monsters vir histologiese studie is van organe met patologiese letsels geneem. Vir molekulêre studies is vyf verskillende nukleïensuur ekstraksie-metodes gebruik om DNS uit die formalien-gefikseerde paraffien-ingebed kadawermonsters te ekstraheer. Pulmonêre monsters is onderwerp aan ’n lyn-ondersoek-toets (“line probe assay”) en polimerase-kettingreaksies (PKR) om mikobakteriële genotipiese verspreiding te bepaal. Twee onafhanklike radioloë het die bors X-strale ondersoek en hulle bevindinge is vergelyk met die pulmonêre bevindinge. PTB is ’n algemene bevinding in die kadawerpopulasie (76.4%) met mans wat meer dikwels geaffekteer is. ’n Vroulike voorkeur vir ekstrapulmonêre TB is waargeneem. TB is statisties geassosieër met pulmonêre patologie, longontsteking en brongiëktase. Sistemiese patologie wat algemeen gevind is in die huidige studie sluit in neoplasmas, koronêre hartsiekte, kolon divertikula, lewer triaditis, sirrose, glomerulosklerose, piëlonefritis en ’n verskeidenheid geneesde maksillofasiale en appendikulêre skeletale frakture. Geëkstraheerde nukleïensuur-konsentrasies, soos bepaal met die NanoDrop® spektrofotometer, het gewissel tussen10ng/μl en 1000ng/μl. Daar is gevind dat die standaard uitsoutings-metode die mees koste-effektief en dus die voorkeur-metode nukleïensuur ekstraksie-metode was. Die HAIN® MTBDRplus® toets was effektief om die aanwesigheid van mikobakteriële spesies wat aan die Mycobacterium tuberculosis kompleks behoort, te bepaal. Sensitiwiteit vir eerste-linie middels kon nie bepaal word nie as gevolg van DNS degradasie. Spoligotipering was onsuksesvol omdat onvoltooide en onidentifiseerbare hibridisasie van die 43 merkers plaasgevind het. Die RD105 en MUB02/RD105 PCR resultate was nie-herhaalbaar en nie-spesifiek. Pulmonêre kavitasie en pleurale verdikking was die enigste bevindinge wat positief gekorreleer is met die radiologiese bevindinge (p<0.05). Na ons wete is hierdie studie die eerste een wat TB en sistemiese patologie ekstensief ondersoek en gebruik maak van histopatologie, molekulêre tegnieke en nadoodse radiologie in kadawers van lae sosio-ekonomiese agtergronde vanaf ’n area met ’n hoë TB las. Hierdie studie verskaf dus ’n meer volledige en deeglike begrip van die voorkoms, verspreiding en morfologie van TB letsels sowel as die assosiasie tussen TB en sistemiese patologie.

Thesis (D.Sc.(Odontology))--University of Pretoria, 2003.
"Published work submitted to the University of Pretoria for the degree of Doctor of Science in Odontology (Oral pathology)". Includes bibliographical references. Also available online.

Objetivos. Describir las características histológicas y endoscópicas que se presentan en pacientes diagnosticados con cáncer gástrico en el Hospital Nacional Daniel Alcides Carrión del Callao. Materiales y métodos. Se realizó un estudio tipo serie de casos que incluyó a todos los pacientes con diagnóstico histológico de cáncer gástrico durante el periodo de enero de 2009 a diciembre de 2011. La información se obtuvo de los registros del servicio de anatomía patológica del Hospital Nacional Daniel Alcides Carrión. Se consignó la edad y sexo de los pacientes, el tipo histológico, la localización endoscópica, así como la presencia de metaplasia intestinal, el grado histológico y la morfología del cáncer. Resultados. Se incluyeron 120 pacientes. La edad promedio fue de 65,4 ± 13,6 años; 59 (49%) fueron de sexo masculino. Según el tipo histológico se encontró el tipo intestinal en 68 (56%); difuso en 45 (38%), y mixto en 7 (6%). Según su localización, 23 (19%) se localizaron en fondo; 52 (43%) en el cuerpo; 39 (33%) en el antro, y 6 (5%) en el píloro. Los pacientes con cáncer gástrico de tipo intestinal presentaron una edad promedio mayor que los que tuvieron el tipo difuso (69,1 ± 10,3 versus 59,3 ± 15,3). De los pacientes con cáncer gástrico tipo intestinal, 60,3% tuvo localización proximal, en comparación a 66,6% de los pacientes con tipo difuso. Conclusión. En la población en estudio, el cáncer gástrico de tipo difuso se presenta a una edad más temprana que el de tipo intestinal, además de estar más frecuentemente localizados a nivel proximal.
Objetivos. To describe the histologic and endoscopic characteristics reported among patients diagnosed with gastric cancer in “Daniel Alcides Carrion” National Hospital in Callao. Materials and methods. We performed a case series including all patients with histological diagnosis of gastric cancer from January 2009 to December 2011. Data were obtained from the registers of the pathology service of Daniel Alcides Carrion National Hospital. Factors such as age and gender of patients, histologic type, endoscopic location, presence of intestinal metaplasia, histologic degree, and cancer morphology were evaluated. Results. 120 patients were included. Mean age was 65.4 ± 13.6 years; 59 (49%) were male. Based on the histologic type, intestinal type was found among 68 (56%); diffuse type among 45 (38%), and a mixed type in 7 (6%). Regarding the site, 23 (19%) of gastric cancers were located in the fundus; 52 (43%) in the body; 39 (33%) in the antrum, and 6 (5%) in the pylorus. Patients with gastric cancer of the intestinal type were in average older than those with a diffuse type (69.1 ± 10.3 versus 59.3 ± 15.3). 60.3% of intestinal-type gastric cancers were located proximally, versus 66.6% of diffuse-type cancers. Conclusion. Among the studied population, diffuse-type gastric cancer appears at an earlier age than the intestinal type, and its most common location is proximal.

Histology is a technique that has any number of diagnostic uses in modern hospital laboratories. However, as a scientific method employed in the study of ancient and mummified remains, it appears to have lost its popularity.This project explores the advantages and limitations of histology as a technique for such studies. In order to do so, soft tissue and bone samples from ten early Roman Period mummies (30 BCE – 250 CE) from the Kellis 1 cemetery in the Dakhleh Oasis have been histologically examined.While this project focuses on the scientific technique of histology, and its application for the study of ancient remains, it also aims to be cross-disciplinary by incorporating scientific results from the ten mummies with the historical data and archaeological remains uncovered during excavations of the Kellis site. By bringing the results of science and Egyptology/archaeology together, it hoped that a better understanding of ancient Egyptian society could be achieved.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

A avaliação da morfologia orofacial sob o enfoque antroposcópico, bem como a mensuração das estruturas orofaciais, é importante aspecto do exame fonoaudiológico, contribuindo para a determinação do diagnóstico, do planejamento terapêutico e do prognóstico dos indivíduos com respiração oral. Os objetivos desta tese foram: 1. descrever as características posturais e morfológicas dos órgãos fonoarticulatórios de crianças respiradoras orais, segundo a idade; 2. descrever as medidas e proporções orofaciais de crianças respiradoras orais, segundo a idade e; 3. comparar as medidas e proporções orofaciais de crianças respiradoras orais com as medidas e proporções orofaciais de crianças sem queixas fonoaudiológicas, segundo a idade. A tese encontra-se dividida em três estudos: Estudo I -Características posturais e morfológicas dos órgãos fonoarticulatórios de crianças respiradoras orais: enfoque antroposcópico; Estudo II - Medidas e proporções orofaciais de crianças respiradoras orais; e Estudo III -Comparação entre medidas e proporções orofaciais de crianças respiradoras orais e de crianças sem queixas fonoaudiológicas. Participaram dos estudos 100 crianças, de ambos os sexos, com idades entre sete anos e 11 anos e 11 meses, leucodermas, em dentição mista, com diagnóstico de respiração oral. No Estudo III, o grupo controle foi composto de 254 crianças, de ambos os sexos, na faixa etária entre sete anos e 11 anos e 11 meses, leucodermas, em dentição mista e sem queixas fonoaudiológicas. As características posturais e morfológicas dos órgãos fonoarticulatórios das crianças respiradoras orais pesquisadas no Estudo I foram posição habitual de lábios e de língua, possibilidade de vedamento labial, hiperfunção do músculo mentual durante a oclusão labial, mordida e morfologia do lábio inferior, das bochechas e do palato duro, por meio da antroposcopia. Os resultados indicaram que os aspectos mais comuns na amostra foram posição habitual de lábios entreaberta, posição habitual de língua no assoalho oral, possibilidade de vedamento labial, hiperfunção do músculo mentual durante a oclusão dos lábios, mordida alterada, lábio inferior com eversão, simetria de bochechas e palato duro alterado. Nos Estudos II e III, as crianças foram submetidas à avaliação antropométrica, sendo que as medidas orofaciais obtidas foram lábio superior, lábio inferior, filtro, terço superior da face, terço médio da face, terço inferior da face, lados da face e distância interincisiva máxima. O instrumento utilizado foi o paquímetro eletrônico digital marca Starrett Série 727. Os resultados do Estudo II evidenciaram que não houve diferença estatisticamente entre a maioria das médias das medidas e proporções orofaciais de crianças respiradoras orais, segundo a idade. Os resultados do Estudo III mostraram que para algumas medidas e proporções orofaciais houve diferença estatística entre as duas populações estudadas. Conclui-se, ao analisar os três estudos, que as alterações antroposcópicas parecem ser mais evidentes nos respiradores orais do que as alterações antropométricas. Por fim, tem-se que a antropometria mostra-se útil na avaliação fonoaudiológica, complementando o julgamento visual com medidas quantitativas.
The evaluation of the orofacial morphology made by anthroposcopic approach, as well as the measurement of orofacial structures, is an important aspect from the speech-language pathology assessment that contributes to determination of diagnosis, management and prognosis of mouth breathing individuals. The purposes of this thesis were: 1. to describe the postural and morphologic characteristics of the stomatognathic system of mouth breathing children, according to age; 2. to describe the orofacial measurements and proportions of mouth breathing children, according to age and; 3. to compare the orofacial measurements and proportions of mouth breathing children to those of children with no history of speech-language pathology disorders, according to age. The thesis is divided in three studies: Study I - Postural and morphologic characteristics of the stomatognathic system of mouth breathing children: anthroposcopic approach; Study II - Orofacial measurements and proportions of mouth breathing children; and Study III - Comparation between measurements and proportions of mouth breathing children and children with no history of speech-language pathology disorders. 100 children participated in the studies, of both sexes, with ages ranging from seven to 11 years and 11 months, leukoderms, in mixed dentition period, with mouth breathing diagnosis. In Study III, the control group was comprised of 254 children, of both sexes, with ages ranging from seven to 11 years and 11 months, leukoderms, in mixed dentition period, with no history of speech-language pathology disorders. The postural and morphologic characteristics of the stomatognathic system of mouth breathing children researched in Study I were labial and lingual resting position, possibility of labial occlusion, mentalis muscle hyperfunction during labial occlusion, bite and morphology of lower lip, cheeks and hard palate, observed by anthroposcopy approach. The results indicated that the most common aspects in the sample were half-open lips in resting position, tongue lowered on the mouth\'s floor in resting position, possibility of labial occlusion, mentalis muscle hyperfunction during labial occlusion, alteration of the bite, labioverted, symmetry of the cheeks and alteration of the hard palate. In Studies II and III, the children were submitted to anthropometric assessment and the orofacial measurements obtained were upper lip, lower lip, philtrum, upper face, middle face, lower face, sides of the face and maximum interincisal distance. The instrument used was the electronic digital sliding caliper Starrett Series 727. The results of Study II showed that there was no statistically difference between the most of averages of the orofacial measurements and proportions of mouth breathing children, according to ages. The results of Study III showed that in some orofacial measurements and proportions there was statistically difference between the two studied populations. In analysis of the three studies, it can be concluded that the anthroposcopic alterations seems to be more evident in mouth breathers than anthropometric alterations. Finally, the anthropometry shows useful in speech-language pathology assessment and supplements visual judgment with quantitative measurements.

Os objetivos deste estudo foram obter medidas antropométricas faciais, a medida interincisiva máxima e proporções faciais em crianças, verificar se há diferença estatisticamente significativa entre as médias das medidas e proporções faciais, segundo idade e sexo, comparar a distância do canto externo do olho ao cheilion do lado direito com o lado esquerdo da face e comparar as médias das medidas antropométricas faciais desta amostra com os padrões de normalidade para crianças norte-americanas. Participaram 254 crianças, 117 do sexo masculino e 137 do sexo feminino, com idades entre 7,0 e 11,11 anos, leucodermas, em dentição mista, sem queixas fonoaudiológicas e/ou histórico de tratamento fonoaudiológico prévio e/ou atual. As medidas antropométricas faciais obtidas foram lábio superior, lábio inferior, filtro, terço superior da face, terço médio da face, terço inferior da face e distância entre o canto externo do olho e o cheilion no lado direito e esquerdo da face. As proporções faciais obtidas foram as estabelecidas entre o lábio superior e o lábio inferior, entre o terço superior da face e o terço médio da face e entre o terço médio da face e o terço inferior da face. O instrumento utilizado foi o paquímetro digital marca Starrett Série 727. Os resultados mostraram que, para o lábio superior e para o filtro, não houve diferença estatisticamente significativa entre as médias segundo idade, em ambos os sexos. Nas demais medidas faciais, observou-se diferença estatisticamente significativa entre as médias, segundo idade. Na maioria das medidas faciais, as meninas apresentaram médias inferiores às obtidas para os meninos. As proporções faciais não apresentaram diferença estatisticamente significativa entre as médias segundo idade, em ambos os sexos. As médias da distância entre o canto externo do olho e o cheilion no lado direito da face foram estatisticamente maiores do que as médias dessa distância no lado esquerdo da face. Os resultados obtidos nesta amostra para o lábio superior, o lábio inferior e o terço inferior da face encontram-se abaixo das médias descritas para as crianças norte-americanas. Os resultados desta amostra, referentes ao filtro, coincidem com as médias descritas para as crianças norte-americanas.
The purposes of this study were to obtain anthropometric facial measurements, the maximum distance between incisors and facial proportions in children, to verify if there is statistically significant difference among the averages of the facial measurements and proportions, according age and sex, to compare the distance from the exocanthion to the cheilion of the right side that of the left side of the face and to compare the averages of the anthropometric facial measurements of this sample with the North American norms. 254 children participated, 117 male and 137 female, with ages ranging from 7,0 to 11,11 years, leukoderm, in mixed dentition period, with no history of speech and swallowing disorders or treatment. The collected anthropometric facial measurements were upper lip, lower lip, philtrum, upper face, middle face, lower face and the distance from the exocanthion to the cheilion of each side of the face. The collected facial proportions were between the upper lip and lower lip, between the upper face and middle face and between middle face and lower face. The used instrument was the electronic digital sliding caliper Starrett Series 727. The results showed that there was no statistically significant difference among averages according age, in both sexes, to the upper lip and to the philtrum. In others facial measurements, statistically significant difference among averages according age was observed. In the majority of facial measurements, girls showed lower averages than boys. The facial proportions did not show statistically significant difference among averages according to age, in both sexes. The averages of the distance from the exocanthion to the cheilion in right side of the face were statistically higher than the averages of the distance from the exocanthion to the cheilion in left side of the face. The results of this sample referring to upper lip, lower lip and lower face were lower than the North American norms for children. The results of this sample referring the philtrum were the same as the North American norms for children.

Orientador: Oslei Paes de Almeida
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O prurigo actínico (PA) é uma fotodermatose familiar específica que afeta principalmente os mestiços, fruto da miscigenação entre índios e europeus, que habitam vários países da América do Norte, Central e do Sul. Pode manifestar-se em qualquer idade, no entanto a doença inicia-se freqüentemente na infância, entre os seis e oito anos de idade. É mais freqüente em mulheres, e atinge principalmente pessoas que vivem em regiões acima de mil metros de altitude. O PA afeta principalmente áreas da pele expostas ao sol. Clinicamente se apresenta de forma polimórfica. O objetivo deste estudo foi analisar as características clínicas, histopatológicas e a expressão de marcadores imunoistoquímicos de 43 casos de PA de lábio. Dezesseis casos envolviam pacientes do gênero masculino e 27 casos (62,80%) do gênero feminino, com idade média de 28,6 anos. Todos os casos envolviam o lábio inferior e outras áreas da face e do corpo, e 17 casos (39,54%) somente apresentavam manifestação em lábio inferior. As principais alterações clínicas eram: crosta, pápulas eritematosas, hiperpigmentação, descamação, placas, úlceras e edema. Microscopicamente observou-se no epitélio superficial principalmente hiperqueratose, ulceração, vacuolização das células da camada basal e exocitose. No conjuntivo subjacente observou-se quadro inflamatório crônico, em muitos casos predominando a presença de folículos linfóides em diversos graus de organização. Nenhum dos casos apresento elastose solar. Os marcadores imunoistoquímicos mostraram que os folículos linfóides apresentavam organização semelhante ao normal. Syndecan-1 marcou as células da camada espinhosa de forma homogênea, mas estava ausente nas células basais e suprabasais. D2-40 com marcação positiva e forte nas células dendríticas do centro folicular e camada basal do epitélio superficial. Mastócitos, eosinófilos e macrófagos estavam distribuídos entre as células linfoplasmocitárias.
Abstract: Actinic prurigo (AP) is a specific familial photodermatosis that affects mainly mestizos, who live in many parts of North, Central and South America. AP can be clinically evident at any age, but it starts in infancy, between 6 and 8 years of age. It is more frequent in women. AP affects mainly persons living in regions above one thousand meters sea level. The disease affects mainly sun exposed skin, andclinically it is polymorphic. The objective of this study was to evaluate the clinical, histological and immunohistochemistry characteristics of 43 cases of AP of the lower lip. Sixteen cases were in males and 24 females (62.8%), with mean age of 28.6%. All cases involved the lower lip and other skin sites, but in 17 cases the lesions occurred only in the lower lip (39.54%). Hyperpigmentation, descamation, plaques, ulcers and edema were the main clinical alterations in our series. Microscopically on the superficial epithelial it was found mainly hyperqueratosis, ulceration, vacuolization of the basal and supra basal layer cells and exocytosis. In the subjacent connective tissue predominated a chronic inflammatory process, in many cases rich in lymphoid follicles in various degrees of organization. In none of the cases it was observed elastosis in the connective tissue. Immunohistochemistry markers confirmed that the follicles showed an organization similar to normal follicles. Syndecan-1 was expressed homogenously in the spinous layers of the superficial epithelium, but it was negative in the basal and suprabasal layers. D2-40 was positive in the dendritic cells of the follicular centers and basal cells of the superficial epithelium. Mast cell, eosinophils, and macrophages were found among the plasmatic cells.
Mestrado
Patologia
Mestre em Estomatopatologia

A atresia das vias biliares é afecção hepática da infância. A etiologia é desconhecida, e o diagnóstico baseia-se na biópsia hepática, cujo achado é a proliferação ductular. A ligadura do ducto biliar comum em ratos é modelo utilizado para estudo das doenças colestáticas. A proposta do trabalho foi estudar, em modelo experimental de obstrução biliar, as alterações histológicas hepáticas em ratos jovens e compará-las com o animal adulto. Avaliou-se a semiquantificação da proliferação ductular e inflamação pelo HE; quantificação da fibrose portal e periportal pelo picrosírius; semiquantificação da expressão de desmina e a-actina de músculo liso pelas células estreladas e miofibroblastos. Apesar das respostas de proliferação ductular e inflamação mais lentas no rato jovem, a fibrose e a expressão de desmina foram mais intensas neste grupo
Biliary atresia is an hepatic disease of infancy. Etiology is unknown, and diagnosis is made by liver biopsy, with ductular proliferation being the main histological feature. Bile duct ligation in rats is an useful experimental model of biliary obstruction. The aim of this study of extra-hepatic cholestasis was analyse hepatic histological alterations in young rats compared to adult animals. The responses were studied by semiquantification of ductular proliferation and inflammatory infiltrated by HE stain; quantification of portal and periportal fibrosis with the sirius-red stain; semiquantification of the expression of desmin and a-smooth muscle actin by the hepatic stellated cells and myofibroblasts. In young animals, despite the very slow response of ductular proliferation and inflammation observed with HE, there were significantly more fibrosis and expression of desmin than in adult group

Brain and nervous system tumors were responsible for around 250,000 deaths in 2020 worldwide. Correctly identifying different tumors is very important, because treatment options largely depend on the diagnosis. This is an expert task, but recently machine learning, and especially deep learning models have shown huge potential in tumor classification problems, and can provide fast and reliable support for pathologists in the decision making process. This thesis investigates classification of two brain tumors, glioblastoma multiforme and lower grade glioma in high-resolution H&E-stained histology images using deep learning. The dataset is publicly available from TCGA, and 220 whole slide images were used in this study. Ground truth labels were only available on whole slide level, but due to their large size, they could not be processed by convolutional neural networks. Therefore, patches were extracted from the whole slide images in two sizes and fed into separate networks for training. Preprocessing steps ensured that irrelevant information about the background was excluded, and that the images were stain normalized. The patch-level predictions were then combined to slide level, and the classification performance was measured on a test set. Experiments were conducted about the usefulness of pre-trained CNN models and data augmentation techniques, and the best method was selected after statistical comparisons. Following the patch-level training, five slide aggregation approaches were studied, and compared to build a whole slide classifier model. Best performance was achieved when using small patches (336 x 336 pixels), pre-trained CNN model without frozen layers, and mirroring data augmentation. The majority voting slide aggregation method resulted in the best whole slide classifier with 91.7% test accuracy and 100% sensitivity. In many comparisons, however, statistical significance could not be shown because of the relatively small size of the test set.

Histopathology refers to the visual inspection of tissue under the microscope and it is the core part of diagnosis. The process of manual inspection of histopathology slides is very time-consuming for pathologists and error-prone. Furthermore, diagnosis can sometimes differ among specialists. In recent years, convolutional neural networks (CNNs) have demonstrated remarkable performances in the classification of digital histopathology images. However, due to their high resolution, whole-slide images are of immense size, often gigapixels, making it infeasible to train CNNs directly on them. For that, patch-level classification is used instead. In this study, a deep learning approach for patch-level classification of glioblastoma (i.e. brain cancer) tissue is proposed. Four different state-of-the-art models were evaluated (MobileNetV2, ResNet50, ResNet152V2, and VGG16), with MobileNetV2 being the best among them, achieving 80% test accuracy. The study also proposes a scratch-trained CNN architecture, inspired by the popular VGG16 model, which achieved 81% accuracy. Both models scored 87% test accuracy when trained with data augmentation. All models were trained and tested on randomly sampled patches from the Ivy GAP dataset, which consisted of 724 H&E images in total. Finally, as patch-level predictions cannot be used explicitly by pathologists, prediction results from two slides were presented in the form of whole-slide images. Post-processing was also performed on those two predicted WSIs in order to make use of the spatial correlations among the patches and increase the classification accuracy. The models were statistically compared using the Wilcoxon signed-rank test.

A doença hepática gordurosa não-alcoólica (DHGNA) e a esteatohepatite (EHNA) são freqüentes nos obesos. O objetivo foi determinar a prevalência de DHGNA/EHNA e Síndrome Metabólica (SM) nos grandes obesos; definir preditores de EHNA; estabelecer critérios histológicos para o diagnóstico da EHNA. Avaliados 325 pacientes encaminhados à cirurgia bariátrica (IMC = 35 kg/m2), dos quais 146 foram submetidos à análise histológica; as variáveis clínicas e bioquímicas analisadas e correlacionadas com a histologia. A DHGNA ocorreu em 111 (76%) pacientes e a prevalência de EHNA, conforme critério histológico usado, em 25,3% a 55,5%; SM ocorreu em 57,2%. Os preditores da EHNA foram: SM; alterações glicêmicas; hipertrigliceridemia e HAS. Foram preditores de fibrose: idade acima de 30 anos e AST elevada
Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) has been associated with obesity. Determine prevalence of NAFLD/NASH and metabolic syndrome (MS) in severe obesity; define clinical predictor of steatohepatitis; establish histological criteria necessary to diagnose NASH. Evaluation of 325 patients submitted to bariatric surgery (BMI = 35 kg/m2), among which 146 were submitted to histological analysis; variables clinical and biochemical were analyzed and correlated to histological characteristics. NAFLD occurred in 111 (76%) patients and NASH, according to histological criteria used, in 25.3% to 55.5%; MS was present in 57.2%. Predictors of NASH: MS; glycaemic alterations; hypertriglyceridaemia and high blood pressure (HBP). Predictors of fibrosis: age above 30 years and high AST

Introdução: A Síndrome do Coração Esquerdo Hipoplásico (SCEH) compreende um espectro de malformações estruturais cardíacas caracterizadas por um hipodesenvolvimento significativo do complexo coração esquerdo-aorta, que apesar da evolução do tratamento, continua sendo um desafio. O objetivo deste trabalho é identificar diferenças morfológicas e histológicas em corações com atresia e estenose mitral na SCEH. Métodos: Estudo de 33 corações com SCEH e nove corações normais (controle), divididos em dois grupos, atresia mitral (AM) e estenose mitral (EM), obtidos em necrópsia e submetidos a análise morfológica dos segmentos da aorta, características da valva mitral e tricúspide, septo inter atrial, miocárdio, cavidades ventriculares e análise histológica com as colorações e hematoxilina/eosina e picro-sírius. Resultados: Observamos nove espécimes com Atresia Mitral e Atresia Aórtica (AMAA), 27,2%; treze com Atresia Mitral e Estenose Aórtica (AMEA), 39,3% e onze com Estenose Mitral e Estenose Aórtica (EMEA) 33,3%. Encontramos associação significativa de predominância de coronárias tortuosas no grupo EM (?2= 4,911; P=0,027) e a dominância coronariana esquerda está em 75% dos casos de EM, com diferença significativa entre os dois grupos (?2=9,298; P=0,01). No grupo AM encontramos correlação significativa entre aorta descendente e arco aórtico (r =0,692; P=0,039) e entre aorta descendente e istmo aórtico (r=0,796; P=0,010).No grupo EM, há correlação significativa entre as variáveis: Anel mitral e comprimento via de entrada de ventrículo direito (r=0,523; P=0,045); Anel mitral e istmo aórtico (r=0,692; P=0,003); ventrículo esquerdo cavidade e aorta ascendente (r=0,643; P=0,010); Arco aórtico e istmo aórtico (r=0,678; P=0,001); Aorta ascendente e arco aórtico (r=0,444; P = 0,044). Não existe diferença significativa no tamanho dos miócitos (coloração HE) entre o grupo AMAA e o grupo EMAA/EMEA (P=0,427), porém existe diferença significativa entre AMAA e controle (P=0,011) e entre EMAA/EMEA e controle (P=0,023). O percentual de colágeno (coloração de picro-sírius) é significantemente diferente entre os três grupos (P=0,0001) e o grupo AM é o que contém maior percentual de colágeno. Conclusões: 1. Na SCEH os corações com EM apresentam significativamente coronárias tortuosas e dominância coronariana esquerda em comparação com AM; 2. No grupo AM encontramos correlação significativa entre o diâmetro da aorta descendente e arco aórtico e entre aorta descendente e istmo aórtico; 3. No grupo EM, há correlação significativa entre as seguintes variáveis: anel mitral e comprimento via de entrada do ventrículo direito, anel mitral e istmo aórtico, cavidade do ventrículo esquerdo e aorta ascendente, arco aórtico e istmo aórtico e arco aórtico e aorta ascendente; 4. Há hipertrofia dos miócitos nos espécimes com AM e EM em comparação com o grupo controle; 5. Na SCEH o percentual de colágeno é superior ao grupo controle; 6. O grupo AM tem maior percentual de colágeno que o grupo EM
Introduction: Hypoplastic left heart syndrome (HLHS) comprises a spectrum of cardiac malformations characterized by a significant underdevelopment of the left heart-aorta complex, which remains a challenge despite the progress of treatment. The objective of this work is to identify morphological and histological differences in hearts with atresia and mitral stenosis with HLHS. Methods: 33 hearts with HLHS divided into two groups, mitral atresia (AM) and mitral stenosis (MS) and nine normal hearts (control),obtained at autopsy, submitted to morphological analysis of aortic segments, mitral and tricuspid valves, atrial septum, infarction, and ventricular cavities and histological study with Hematoxylin/eosin and picro sírius stain. Results: There were nine specimens with aortic atresia and mitral atresia (AMAA), 27.2%; thirteen with atresia Mitral and Aortic Stenosis (AMEA), 39.3% and eleven with Mitral Stenosis and Aortic Stenosis (EMEA) 33.3%. There is a significant association of prevalence of coronary tortuous in the MS group (x2 = 4.911, P=0.027) and left coronary dominance in 75% of cases of MS, with a significant difference between the two groups (x2 2 = 9.298, P=0,01). In the AM group we found a significant correlation between the descending aorta and aortic arch (r=0.692, P=0.039) and between the descending aorta and aortic isthmus (r =0.796, P=0.01). In the MS group there was a significant correlation between variables: mitral ring and length inlet right ventricle (r= 0.523, P=0.045), mitral and aortic isthmus (r=0.692, P=0.003), left ventricular cavity and ascending aorta (r=0.643, P=0.01); Aortic arch and aortic isthmus (r=0.678, P=0.001), ascending aorta and aortic arch (r=0.444, P=0.044).There is no significant difference in the size of myocites (HE staining) between the group and the group AMAA EMAA / EMEA (P = 0.427), but we found significant difference between AMAA and control (P = 0.011) and between EMAA / EMEA and control (P=0.023). The percentage of collagen (picrosirius staining) is different between the three groups (P=0.0001) and AM is the group that contains a higher percentage of collagen. Conclusions: 1. In HLHS hearts with MS present significant tortuous coronary and left coronary dominance compared with AM; 2. In the AM group there is a significant correlation between the diameter of the descending aorta and aortic arch and descending aorta and across the aortic isthmus; 3. In the MS group, there was significant correlation between the following variables: length and mitral inflow tract, mitral and aortic isthmus, left ventricular cavity and the ascending aorta, aortic arch and isthmus aorta and aortic arch and ascending aorta; 4. There is myocite hypertrophy in specimens with AM and EM compared with control; 5. In the HSLS collagen percentage is higher than control; 6. The AM group has a higher percentage of collagen than the EM group

Thesis (M.S.)--Boston University
The following thesis proposes the question if current scientific data supports the hypothesis that an acute myocardial infarction, not identified by gross symptoms, can be visualized by using apoptotic signaling biomarkers as a diagnostic tool to complement a post-mortem autopsy. The biochemistry and mechanisms of irreversible cellular death is presented and supported through published experimental, clinical and case studies. Furthermore, the aforesaid biomarkers have been observed in the cardiac myocyte in elevated levels associated with hypoxic ischemia. In addition, the physical characteristic of DNA fragmentation is addressed to visualize apoptotic injury due to hypoxic ischemic conditions. Although the quality of evidence lacked published data to suggest one immunochemical staining method positively identifies a myocardial infarction, there is adequate data to suggest that a combination of staining methods can be utilized as a tool to positively identify and diagnose an acute myocardial infarction.

O significado prognóstico do fenômeno de regressão espontânea em melanoma, especialmente nas lesões finas, tem sido controverso. Estudos recentes sugerem que regressão extensa e tardia (fibrótica) possa estar relacionada a pior prognóstico. Linfangiogênese e angiogênese predizem metástase em melanoma. Objetivos: Analisar a densidade microvascular linfática e panvascular em melanomas extensivo-superficiais finos (Breslow 1,0 mm), comparando: melanomas regressivos e não-regressivos, área regressiva e não-regressiva de um mesmo tumor , os diferentes estágios de regressão (precoce ou inflamatória e tardia) de um mesmo tumor e correlacionar angiogênese e linfangiogênese a fase de crescimento tumoral. Métodos: Análise retrospectiva, histopatológica e estudo imunoistoquímico de melanomas com os anticorpos monoclonais D2-40 (37 tumores, sendo 16 regressivos e 21 não-regressivos como controles) e CD31 (29 tumores, sendo 13 regressivos e 16 não regressivos como controles), e posterior quantificação da densidade microvascular por análise de imagem. Resultados: Foi encontrada maior densidade microvascular linfática na fase tardia de regressão quando comparada à área dos melanomas regressivos que não apresentava regressão (controle interno). Conclusões: A fase tardia da regressão espontânea nos melanomas finos apresentou maior densidade microvascular linfática, fato que pode relacioná-la a pior prognóstico, já que densidade microvascular linfática estaria relacionada a risco aumentado de disseminação metastática. Essa suposição necessita ser confirmada por um maior seguimento dos nossos casos para detecção de metástases linfonodais
The prognostic significance of spontaneous regression in melanoma, especially thin lesions, has been a controversial issue. Recent studies suggest that extensive and late regression may be related to worse prognosis. Angiogenesis and lymphangiogenesis predict metastatic spread in melanoma. Objectives: To quantify lymphatic and panvascular microvascular density in thin (Breslow 1,0 mm) superficial spreading melanomas comparing: regressive and non-regressive melanomas, regressive and non-regressive areas from the same tumor; early and late histological stages of regression in the same tumor and to correlate angiogenesis and lymphangiogenesis and tumor growth phase. Methods: We conducted retrospective study, histological examinations and immunohistochemical analyses using the monoclonal antibodies D2-40 (37 melanomas, 16 regressive and 21 non-regressive as controls) and CD31 (29 melanomas, 13 regressive and 16 non-regressive as controls) with subsequent quantification of microvascular lymphatic and panvascular density by image analysis. Results: We found greater lymphatic microvascular density in the late stage of regression compared with non-regressive area (internal control) of regressive melanomas. Conclusions: The late stage of spontaneous regression in thin melanomas showed greater lymphatic microvascular density and this may be related to worse prognosis as lymphatic microvascular density is related with increased risk of metastatic spread. This supposition must be confirmed by a longer follow-up for detection of lymph node metastases

La fibrillation atriale (FA) est l'arythmie cardiaque la plus couramment rencontrée en pratique clinique. Sa pathophysiologie étant encore mal connue, elle est difficile à traiter. Plusieurs paramètres ont été décrits comme impliqués dans l'initiation de la fibrillation atriale ; cependant, les mécanismes précis d'initiation de la fibrillation atriale ne sont pas élucidés. Dans cette étude, des approches histologiques, biochimiques, transcriptomiques et génétiques seront abordées afin d'identifier les substrats intervenant dans l'initiation de la fibrillation atriale humaine. Ainsi, il a été mis en évidence des cellules interstitielles de type Cajal au sein des manchons myocardiques des veines pulmonaires pouvant être à l'origine des foyers ectopiques, une possible origine embryonnaire précoce via l'absence d'expression du gène pitx2 chez les patients en fibrillation atriale, une surexpression des voies du système nerveux autonome à la fois adrénergique et cholinergique, une modification du flux potassique du courant IKs via une intervention des protéines régulatrices KCNE et de protéines du cytosquelette musculaire. De plus, une des complications de la fibrillation atriale est la survenue d'accidents vasculaires cérébraux ; il a été montré dans cette étude une surexpression au niveau de l'oreillette gauche du facteur Von Willebrand chez les patients en fibrillation atriale ainsi qu'une augmentation du VEGF sérique dans la forme paroxystique de la fibrillation atriale. Ces nouvelles données permettent d'accroître les connaissances de la fibrillation atriale et d'envisager par la suite la possibilité de nouvelles stratégies thérapeutiques plus efficaces.

Existing computational pathology approaches did not allow, yet, the emergence of effective/efficient computer-aided tools used as a second opinion for pathologists in the daily practice. Focusing on the case of computer-based qualification for breast cancer diagnosis, the present article proposes two deep learning architectures to efficiently and effectively detect and classify mitosis in a histopathological tissue sample. The first method consisted of two parts, entailing a preprocessing of the digital histological image and a free-handcrafted-feature Convolutional Neural Network (CNN) used for binary classification. Results show that the methodology proposed can achieve 95% accuracy in testing with an F1-score of 94.35%, which is higher than the results from the literature using classical image processing techniques and also higher than the approaches using handcrafted features combined with CNNs. The second approach was an end-to-end methodology using semantic segmentation. Results showed that this algorithm can achieve an accuracy higher than 95% in testing and an average Dice index of 0.6 which is higher than the results from the literature using CNNs (0.9 F1-score). Additionally, due to the semantic properties of the deep learning approach, an end-to-end deep learning framework is viable to perform both tasks: detection and classification of mitosis. The results showed the potential of deep learning in the analysis of Whole Slide Images (WSI) and its integration to computer-aided systems. The extension of this work to whole slide images is also addressed in the last two chapters; as well as, some computational key points that are useful when constructing a computer-aided-system inspired by the described technology.
Trabajo de investigación

INTRODUÇÃO: O conhecimento anatômico desempenha importante papel no desenvolvimento de técnicas diagnósticas e cirúrgicas. Com esse objetivo, na área cardiológica, se mostra fundamental para o entendimento do processo de remodelamento cardíaco que acompanha as cardiomiopatias dilatadas (CMD) tanto isquêmicas (CMDIsq) como idiopáticas (CMDId), de modo particular do ventrículo esquerdo (VE) e sua correlação com alterações do anel atrioventricular esquerdo, levando a graus variáveis de insuficiência cardíaca (IC). OBJETIVOS: Os objetivos desta pesquisa são: 1) Obter medidas do anel atrioventricular esquerdo (mitral) e do ventrículo esquerdo em corações normais, com CMDIsq ou CMDId, comparando-as entre si; 2) Analisar a proporcionalidade entre segmentos da câmara ventricular esquerda dos corações com CMDIsq ou CMDId em relação ao normal; 3) Determinar a esfericidade ou não da câmara ventricular esquerda nos corações com CMDIsq ou CMDId. MÉTODO: Foram analisados 43 corações humanos, divididos em três grupos: NORMAL (n=10), CMDIsq (n=15) e CMDId (n=18). De posse da medida da distância do sulco atrioventricular posterior até o ápice do VE, foram realizados cortes transversais baso-apicais seqüenciais e, após digitalização dos mesmos, por meio de método computadorizado, foram obtidas medidas perimetrais e espessura das paredes. Empregando-se o mesmo método, mensurou-se o perímetro do anel mitral. Foram criados índices de proporção porcentual entre os perímetros dos segmentos provenientes dos cortes do VE, comparando-os intergrupos. Nos dilatados os perímetros segmentares mensurados foram comparados com os perímetros esperados se considerássemos a câmara ventricular como uma esfera perfeita. Realizou-se a análise estatística dessas medidas e índices. RESULTADOS: O perímetro do anel mitral teve o seguinte resultado: somente o grupo CMDIsq teve média significativamente maior que o grupo NORMAL e houve baixo coeficiente de correlação com os perímetros ventriculares segmentares nos corações dilatados. Distância do sulco atrioventricular até o ápice do VE: CMDId = CMDIsq > NORMAL. Perímetros segmentares ventriculares basais (PerB), equatoriais (PerE) e apicais (PerA): grupo NORMAL-> PerE = PerB > PerA; grupos CMDId e CMDIsq- > PerE > PerB > PerA, sendo que o grupo CMDId teve essas 3 medidas maiores que o grupo CMDIsq e ambos tiveram essas 3 medidas maiores que o grupo NORMAL. Nos 3 grupos as medidas de espessura das paredes ventriculares foram iguais estatisticamente. O índice de proporção perimetral PerB/PerE foi igual nos 3 grupos, enquanto o índice PerA/PerE foi igual entre os corações dilatados, mas em ambos foi menor que no grupo NORMAL. Todos perímetros segmentares ventriculares dos corações dilatados foram menores do que os calculados segundo a fórmula da esfera. CONCLUSÕES: 1) O anel atrioventricular esquerdo dilata-se na CMDIsq, sendo essa alteração independente da dilatação dos três segmentos do VE; 2) Os corações com CMDId e CMDIsq desenvolvem uma similar dilatação longitudinal do VE; 3) Ocorre uma dilatação trans versal do VE nessas afecções, sendo essa maior nos corações com CMDId; 4) A espessura das paredes ventriculares esquerdas dos corações com CMDIsq ou CMDId não se altera quando comparada aos corações normais; 5) A dilatação transversal da câmara ventricular esquerda nos corações com CMD não se dá de forma proporcional ao longo do seu eixo longitudinal, sendo mais acentuada nas regiões basal e equatorial; 6) A câmara ventricular esquerda nos corações com CMD de origem isquêmica ou idiopática não apresenta formato esférico.
BACKGROUND: Anatomic knowledge is the cornerstone for the development of surgical and diagnostic image techniques and for understanding pathological entities. Understanding cardiac anatomy is essential for understanding cardiac remodeling in both ischemic and idiopathic dilated cardiomyopathies. Dysfunction in the physiological relationship between the morphology of left ventricle and its mitral ring plays an important role in the cardiac insufficiency etiopathogenesis. OBJECTIVES: 1) To compare morphology of left ventricle and its mitral ring among normal, ischemic and idiopathic dilated cardiomyophatic anatomic specimens; 2) To compare intra specimen ventricular segmental perimeters relationships between normal and dilated specimens; 3) To verify the presence of the spheroid shape of left ventricular chamber in dilated specimens. METHODS: It was analyzed 43 specimens of human hearts, classified in three groups: normal (n=10), dilated due to ischemic (n=15) or idiopathic cardiomyopathies (n=18). Several lengths were measured: the length from the posterior atrioventricular sulcus to the ventricular apex in the intact specimen; followed by three sequential transversal ventricular slicing in the basal, equatorial and apical level. Digital pictures were taken from these slices, in order to be analyzed in a computer assisted fashion. Internal perimeter and ventricular walls width of each slice were measured, as well the mitral ring perimeter. The three intra group perimeters were compared and correlated between themselves. Basal, equatorial and apical perimeter of each group was compared to their correspondent pairs inter groups. Regarding intra group relationships, for a given group, each slice perimeter was measured and considered as a percentage of the equatorial slice (index). This percentage was compared inter groups. Three perimeters were evaluated in both dilated groups, each one was compared to its expected value when considering left ventricular chamber as a perfect sphere (hypothesis). Measurements and index statistical analysis was performed. RESULTS: Mitral ring perimeter was longer than the NORMAL group only in ischemic group. There was a low correlation coefficient between mitral ring perimeter and ventricular segmental perimeters in both dilated groups. Longitudinal length from the left atrioventricular sulcus until the apex was similar in dilated specimens and higher compared to the normal group. Regarding sequential perimeters of ventricular slices in the normal specimens, the equatorial perimeter was as long as the basal ones, but both of them longer than the apical one. In the other hand, for dilated specimens, equatorial diameter was the longest one and apic al the smallest one. Comparing ventricular slices perimeters between dilated groups, all the perimeters lengths were longer in the idiopathic group than in the ischemic one. All the ventricular slices perimeters were longer for both dilated groups than for the normal group. There was no difference of ventricular wall width between groups. The proposed index of proportional perimeter: considering the proportion between basal and equatorial perimeter, there was no difference between any groups; but considering the proportion between apical and equatorial perimeter, dilated specimens displayed a lower index when compared to normal specimens. All the observed ventricular slice perimeters were smaller than the hypothetical (sphere) expected ones in both dilated groups. CONCLUSIONS: 1) Left atrioventricular ring dilatation occurs in ischemic dilated cardiomyopathy and it is independent of the dilatation of segments (apical, basal and equatorial) ventricular; 2) Longitudinal left ventricular dilatation is similar between dilated groups; 3) A transversal ventricular chamber dilatation was observed in dilated diseases and it is greater in the idiopathic disease; 4) The left ventricular wall widths in both dilated cardiomyopathies were similar to normal hearts; 5) Transversal dilatation of left ventricular chamber in both dilated cardiomyopathies is not proporcional along their longitudinal axis because it is more accentuated in equatorial and basal regions; 6) Left ventricular chamber in both dilated cardiomyopathies does not keep spherical shape.

Le mélanome acro-lentigineux (ALM) est le 4ème sous-type histologique de mélanome et représente moins de 10% des mélanomes. Beaucoup de controverses entourent ce sous-type rare, comme un plus mauvais pronostic. L'objectif de notre travail était de mieux caractériser l'ALM sur le plan épidémiologique, clinique, histologique, et évolutif et d'identifier d'éventuels facteurs pronostiques. Entre 1996 et 2004, 126 cas d'ALMs (6% des mélanomes) ont été répertoriés et suivis dans le service de dermatologie de l'Hôpital de l'Hôtel-Dieu, Lyon. Toutes les lames histologiques ont été récupérées et systématiquement relues. Les analyses statistiques ont été réalisées par comparaison de sous-groupes, calculs et comparaison des courbes de survie par la méthode de Kaplan-Meier et le test de Log-Rank, et recherche de facteurs pronostiques indépendants en utilisant le modèle de régression logistique de Cox. La survie médiane sans récidive et spécifique étaient respectivement de 10,1 et 13,5 ans. Le taux de survie à 5 ans était de 76%. Dans la première partie de notre travail, nous avons étudié toutes les caractéristiques épidémiologiques et cliniques de l'ALM, afin de mieux comprendre l'histoire clinique. Les hommes avaient un plus mauvais pronostic ainsi que les formes achromiques. La seconde partie est une étude détaillée des particularités anatomo-pathologiques des ces tumeurs, avec une évaluation de leur signification pronostique. L'analyse multivariée des facteurs pronostiques a permis de souligner l'impact de l'index mitotique et de la présence de microsatellites en histologie. Enfin, la troisième partie de notre travail avait pour but de préciser les critères dermoscopiques d'aide au diagnostic de l'ALM, dont le retard diagnostique est fréquent. A partir d'une des plus grandes séries de cas d'ALM, notre travail souligne le caractère distinct de ce sous-type de mélanome, dont le mauvais pronostic est vraisemblablement lié à un stade avancé au diagnostic, la dermoscopie constituant une aide précieuse pour un diagnostic plus précoce.

With the increasing amount of information needed for diagnosis and therapeutic decision-making, and new trends such as “personalized medicine”, pathologists are expressing an increasing demand for automated tools that perform their most recurrent tasks in their daily practice, as well as an increase in the complexity of the analyses requested in their research activities. With current advances in histopathology, oncology, and biology, the current questions require the analysis of protein expression - evidenced using immunohistochemical (IHC) staining - within specific histological structures or tissue components, or the analysis of the co-expression of several proteins in a large number of tissue samples. In this Ph.D. thesis, we developed innovative solutions to make these analyses available for pathologists. To achieve this objective, we have used recent “machine learning” and, in particular, “deep learning” methodologies. We addressed different problems such as image normalization, to solve the important problem of inter-batch variability of IHC staining, and the automatic segmentation of histological structures, to compartmentalize protein expression quantification. Finally, we adapted image registration techniques to Tissue MicroArray (TMA) slide images to enable large-scale analyses of IHC staining colocalization. While imagenormalization will improve study reproducibility, the tools developed for automated segmentation will drastically reduce time and expert resources required for some studies as well as errors and imprecision due to the human factor. Finally, the work on image registration can provide answers to complex questions that require studying the potential interaction between several proteins on numerous histological samples.
Avec la quantité croissante d’informations nécessaires au diagnostic et à la prise de décision thérapeutique, et le développement de la “médecine personnalisée”, les pathologistes ont un besoin croissant d’outils automatisés pour exécuter leurs tâches les plus récurrentes. Ces outils se doivent également de réaliser des tâches de plus en plus complexes. En effet, avec les progrès récents en histopathologie, oncologie et biologie, les questions actuelles demandent, par exemple, l’analyse de l’expression de protéines révélées par marquages immunohistochimiques (IHC) au sein de structures ou compartiments histologiques spécifiques, ou encore l’analyse de la co-expression de plusieurs protéines dans un grand nombre d’échantillons. Dans cette thèse de doctorat, nous avons développé des solutions innovantes pour mettre ce type d’analyse à la disposition des pathologistes. Pour atteindre cet objectif, nous avons notamment fait appel à des méthodologies récentes de “machine learning” et, particulièrement, de “deep learning”. Nous avons ainsi abordé différentes questions telles que la normalisation d’images, pour résoudre l’important problème de la variabilité des marquages IHC, et la segmentation automatique de structures histologiques, pour permettre une quantification compartimentée de l’expression de protéines. Enfin, nous avons adapté des techniques dites de “recalage” aux images de lames de Tissue MicroArrays (TMA) pour permettre des analyses de colocalisation de marquages IHC à grande échelle. Alors que la normalisation des images améliore la reproductibilité des évaluations de marquages IHC, les outils développés pour la segmentation automatisée permettent de réduire significativement le temps et les ressources expertes nécessaires, ainsi que les erreurs et imprécisions dues au facteur humain. Enfin, les travaux sur le recalages d’images permettent d’apporter des éléments de réponse à des questions complexes qui nécessitent d’étudier l’interaction potentielle entre plusieurs protéines sur de nombreux échantillons histologiques.
Doctorat en Sciences de l'ingénieur et technologie
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Les anatomopathologistes disposent d’outils permettant d’assister leurs décisions cliniques et d’évaluer les risques de récidive des patientes atteintes d’un cancer du sein. Parmi ceux-ci, le grade histologique du cancer du sein divise les patientes en trois sous-groupes pour lesquels le grade histologique 1 et 3 sont respectivement associés à de bons et mauvais pronostics. Cependant, cet outil est loin d’être parfait, dû au manque de reproductibilité de ce système et du risque de récurrence intermédiaire, peu informatif, des patients classés dans la catégorie « grade 2 ».

Afin de mieux caractériser ces tumeurs de risque intermédiaire, notre laboratoire a introduit un score appelé « Gene expression Grade Index (GGI) », basé sur l’expression de 97 gènes définis par microarrays. De façon intéressante, ce GGI permet de diviser les patientes de grade histologique 2, sur base de leur profil d’expression, en 2 groupes correspondant aux tumeurs de grade 1 ou aux tumeurs de grade 3. Cependant, bien que le GGI apporte une information importante, son applicabilité clinique est limitée par son prix et la nécessité d’utiliser du matériel congelé.

Durant ce travail de thèse, nous avons transposé la signature microarrays en un test RT-PCR, appelé PCR-GGI, basé sur l’expression de 8 gènes qui permet de reproduire les performances du GGI à partir de tissus congelés ou conservés dans de la paraffine. Cette amélioration permet de faciliter son utilisation en routine clinique.

De plus, nous avons approfondi notre connaissance du grade histologique, au niveau génomique et transcriptomique, et montré que les tumeurs mammaires (ER-positives) peuvent être divisées en deux groupes :un premier groupe de faible instabilité génomique, exprimant faiblement les gènes de prolifération et présentant un faible risque de récurrence ;et un deuxième groupe de haute instabilité génomique (impliquant principalement des amplifications localisées dans les régions 8q et 20q), une expression importante de gènes de prolifération et un mauvais pronostic.

D’autre part, les carcinomes canalaires in situ (DCIS) présentant des similarités avec les tumeurs invasives, nous avons voulu mieux comprendre le comportement du grade tumoral parmi ces tumeurs pré-invasives. Nous avons donc intégré le PCR-GGI au VNPI et défini le VNPI-GGI. Comparé au VNPI classique, le VNPI-GGI identifie mieux les patientes qui vont récidiver tôt dans les groupes de risque intermédiaire et haut, et permet donc d’éviter le sur-traitement.

Cependant, le calcul du VNPI est un travail fastidieux et le PCR-GGI seul ne permet pas de prédire les risques de récidives des DCIS. Nous avons donc cherché un nouveau marqueur pronostique. Alors, qu’il existe des preuves de plus en plus nombreuses supportant l’importance du rôle anti-tumoral des cellules myoépithéliales, nous avons montré qu’une diminution de l’expression de CD10 – un marqueur des cellules myoépithéliale – était hautement corrélée au risque de récidive. Ces résultats soulignent l’importance tant de l’agressivité de la tumeur que de son environnement directe, dans la progression tumorale.

En terme d’applications, les résultats obtenus durant ce travail de thèse nous ont permis de développer des outils utilisables par les cliniciens afin d’améliorer la prise en charge des patientes.

Traditional histopathological tools routinely used to evaluate breast cancer prognosis are designed to assist physicians in their evaluation of clinical outcome. The histological grade of invasive breast cancer, that assigns patients to one of 3 groups for which histological grade 1 and 3 tumors are respectively associated with lower and higher rate of recurrence, has long provided clinically important prognostic information. However, this tool is far from perfect due to concern over reproducibility and intermediate risk of recurrence of the histological grade 2 that is not informative for clinical decision.

To better characterize tumors classified as histological grade 2, our group has introduced a score called Gene expression Grade Index (GGI) based on a cassette of 97 genes defined by Microarrays. Interestingly, the GGI was able to reclassify patients with histological grade 2 tumors into 2 groups with distinct clinical outcomes similar to those of histological grade 1 and 3, respectively. However, its clinical applicability still remains expensive and often requires frozen tissue.

During this thesis work, we have transposed the GGI onto a qRT-PCR assay, called PCR-GGI, based on a set of 8 genes that could recapitulate in an accurate and reproducible manner the prognostic performance of GGI using both frozen and paraffin-embedded (FFPE) tumor samples, to facilitate its use in clinical practice.

Moreover, we have explored histological grade of invasive breast cancer at genomic and transcriptomic level and we have shown that two classes of ER-positive invasive breast cancer are observed: a first of low genomic instability, low proliferation gene expression and low risk of recurrence; and a second of high genomic instability (implying a major role for amplification of region located on chromosome arms 8q and 20q), high proliferation gene expression and worse prognosis.

In addition, since Ductal Carcinoma in situ (DCIS) and invasive breast cancer show concordant biologic behavior, we attempted to better understand the molecular basis of grade in pre-invasive breast cancer. We have then incorporated the PCR-GGI in the VNPI and defined the VNPI-GGI to improve its prognostic value. Compared to the classic VNPI, the VNPI-GGI had a better potential to identify early relapsing patients in the intermediate and high score group, and avoid under treatment in high-risk DCIS patients.

However, VNPI scoring is a tedious work and PCR-GGI alone can’t predict recurrence in pre-invasive breast cancer. We aimed then to find news prognosis marker in the field of DCIS. As there is now growing body of evidence supporting the role of myoepithelial cells (MECs) as natural tumor suppressors, we have showed that a decrease of CD10 expression- a surface biomarker of MECs – was significantly associated with an increased risk of relapse.

These results highlight the importance of assessing intrinsic DCIS properties as well as juxta-tumoral stroma, both seems to have a major role in DCIS progression.

In terms of applications, from these results obtained during this thesis work, we developed methods applicable into clinical practice to improve patients management.

Doctorat en Sciences biomédicales et pharmaceutiques
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Introdução: A insuficiência cardíaca congestiva (ICC) ocasionada pela cardiomiopatia dilatada idiopática (CMDId) constitui-se em quadro causador de grande impacto na saúde pública, apresentando morbidade e mortalidade significativas, porém muitos aspectos referentes à sua fisiopatologia ainda permanecem desconhecidos, de modo que trabalhos que estudem tais aspectos poderão contribuir para melhor entendimento desta entidade. Objetivos: Avaliar aspectos anatômicos e histológicos de corações com CMDId e compará-los a um grupo controle de corações normais, obtendo-se as medidas dos perímetros dos anéis atrioventriculares direito (AVD) e esquerdo (AVE) e dos ventrículos direito (VD) e esquerdo (VE) bem como a porcentagem por área de fibras colágenas e elásticas dos anéis atrioventriculares direito e esquerdo. Métodos: Foram analisados 13 corações de pacientes que faleceram vítimas de CMDId e 13 corações normais de pacientes que faleceram por causas não relacionadas à doenças cardiovasculares. Os corações foram fixados em formol, dissecados de forma a manter-se apenas os anéis atrioventriculares e a massa ventricular, com posterior laminação desta em segmentos transversais correspondentes a 20%, 50% e 80% da distância compreendida entre o sulco atrioventricular e o ápice ventricular esquerdo. Os cortes assim obtidos foram submetidos à digitalização fotográfica, que permitiu a aferição de ambos os perímetros ventriculares por meio de software específico, tornando possível a comparação de tais medidas entre os grupos e os segmentos. Os anéis atrioventriculares foram posteriormente dissecados, fotografados e medidos digitalmente para aferição das medidas perimetrais a direita e a esquerda, sendo posteriormente enviados ao laboratório de anatomia patológica, sendo realizadas colorações por meio de hematoxilinaeosina, picrossírius e resorcina fuccina oxidada, permitindo estudo das fibras colágenas e elásticas. Resultados: Com relação aos segmentos ventriculares, notou-se que no grupo CMDId ocorre dilatação nos segmentos apical, equatorial e basal, tanto a direita quanto a esquerda A medida do AVD foi maior no grupo CMDId , não havendo diferença estatisticamente significante com relação ao AVE entre os dois grupos. Com relação ao percentual por área de fibras colágenas, tanto o AVE quanto o AVD apresentaram percentagem de fibras menor no grupo CMDId em relação ao grupo normal. Com relação ao percentual por área de fibras elásticas, não houve diferença entre os grupos. Conclusões: Ocorre alteração da geometria ventricular com dilatação tanto a direita quanto a esquerda no grupo CMDId, porém com comportamento distinto entre o VE e o VD. O anel atrioventricular esquerdo não se dilata, ao contrário do direito, a despeito do fato de em ambos ocorrer diminuição da área total de colágeno, sugerindo que o mecanismo de dilatação possa apresentar particularidades oriundas de diferenças estruturais e pressóricas em ambos os ventrículos
Introduction: Congestive heart failure caused by idiopathic dilated cardiomyopathy causes great impact on public health, with significant morbidity and mortality, but many aspects related to its pathophysiology remain unknown, so further studies can contribute to better understanding of this entity. Objectives: To evaluate anatomical and histological aspects of hearts from patients who died victims of idiopathic dilated cardiomyopathy and compare them to a control group, to evaluate the behavior of the perimeters of the right and left atrioventricular rings and left and right ventricles and to compare the percentage area of collagen and elastic fibers of the right and left atrioventricular rings in both groups. Methods: We analyzed 13 hearts of patients who died from idiopathic dilated cardiomyopathy and 13 normal hearts from patients who died of causes not related to cardiovascular disease. The hearts were fixed in formalin, dissected in order to keep only the ventricular mass and atrioventricular rings, with subsequent lamination of segments corresponding to 20%, 50% and 80% of the distance between the atrioventricular groove and the left ventricular apex . The sections obtained were subjected to photo scanning, which allowed the measurement of ventricular perimeters by means of specific software, making it possible to compare these measures between groups and segments. The atrioventricular rings were then dissected, photographed and measured digitally to evaluate the right and left perimeters, later being sent to the pathology laboratory, and stained by hematoxylin-eosin, picrosirius and oxidized resorcin fuccin, enabling study of collagen and elastic fibers. Results: Regarding to ventricular segments, it was noted that in the idiopathic dilated cardiomyopathy group dilation occurs in the apical, equatorial and basal segments, at both sides, and the right atrioventricular ring measurement was higher in idiopathic dilated cardiomyopathy group, with no statistically significant difference in the left side between the two groups. With respect to the percentage by area of collagen fibers, both the left and the right sides had lower percentage of fibers in the idiopathic dilated cardiomyopathy group compared to the normal group. With respect to the percentage by area of elastic fibers, there was no difference between the groups. Conclusions: There is a change in ventricular geometry in idiopathic dilated cardiomyopathy group, but with different behavior between the left and right ventricles. The left atrioventricular ring does not dilate, in spite of the fact that in both ventricles there is lowering of the total area of collagen, suggesting that the mechanism of dilation may present peculiarities arising from structural differences and pressure load in both ventricles

La drépanocytose est la maladie moléculaire et héréditaire (transmission mendélienne récessive et autosomique) la plus répandue au monde. Elle est un problème de santé publique par sa gravité et ses implications socio-économiques dans de nombreux pays. Seuls les sujets homozygotes (SS) ou hétérozygotes composites (SC) sont malades, les hétérozygotes (AS) ne sont que des transmetteurs du gène S. Elle est la première cause d’OstéoNécrose de la Tête Fémorale (ONTF), douloureuse évoluant vers l’arthrose, en l’absence de traitement chez un patient jeune.

La Guadeloupe compte 450.000 habitants, dont 12% sont porteurs de l’hémoglobine S. Le nombre des drépanocytaires est estimé à 1.200 dont les 3/4 sont suivis au Centre Caribéen de la Drépanocytose (CCD), créé en 1990. Le centre assure la prise en charge médicale des enfants dès leur naissance et des adultes malades. Nos activités au CHU de Pointe-à-Pitre, au CCD et à l’Unité INSERM-UMR S458 depuis juillet 1992 nous ont permis d’étudier:

- le diagnostic de l’ONTF;

- l’évaluation de l’hyperpression osseuse dans l’ONTF et l’évaluation du traitement par forage simple;

- l’étude de l’impact de la prise en charge orthopédique précoce sur la survenue et l’évolution de l’ONTF.

Notre étude concerne les patients drépanocytaires adultes homozygotes (SS) et double hétérozygotes (SC):

- une série rétrospective de 1993-1994 [E-1994] portant sur 115 patients (58 SS, 57 SC) identifiés en 1984,

sans suivi médical ni orthopédique;

- une série prospective de 1995 à 2008 [E-2008] portant sur 215 patients (94 SS, 121 SC) avec prise en

charge médicale et orthopédique.

L’IRM est l’examen de référence pour le diagnostic de l’ONTF comme dans la nécrose idiopathique. En absence d’imagerie moderne, la radiographie traditionnelle réalisée de façon complète (profil et, surtout, faux profil), permet le diagnostic avant toute déformation. Seules les lésions cliniquement symptomatiques et évolutives (examen clinique itératif, contrôle radiologique, tomographie, TDM ou IRM) ont une indication opératoire.

L’hyperpression intra osseuse, dans l’ONTF drépanocytaire, est significativement liée à la douleur (que les patients soient homozygotes ou hétérozygotes). Sa diminution a un effet antalgique objectif, observée après forage. Elle permet de confirmer le diagnostic d’ostéonécrose au stade précoce, dans les régions où l’IRM est inexistante.

Un forage réalisé aux stades précoces de l’ONTF permet un arrêt rapide de l’évolution des lésions vers une arthrose, avec une efficacité certaine pour les stades I et II. Il garde une efficacité limitée pour le stade III. En plus de l’indolence apportée par la décompression, le bénéfice du forage se manifeste par l’allongement du délai avant arthroplastie (de 7,4 ± 2,7 ans). La technique est réalisable dans les régions sous équipées, où la drépanocytose est fréquente.

La description histologique aux différents stades radiologiques de l’ONTF montre toujours des lésions de nécrose médullaire et osseuse. A l’inverse des lésions idiopathiques, les lésions drépanocytaires sont caractérisées par la présence d’une inflammation, en dehors de tout processus infectieux.

Dans la littérature, la fréquente de l’ONTF drépanocytaire chez l’adulte est voisine de 40%, proche de celle observée dans [E-1994], notre population non suivie (36,5%). En comparant les études [E-1994] et [E-2008], la fréquence de l’ONTF passe de 36,5% à 14,4%. L’officialisation en 1992 d’une prise en charge médicale et d’un suivi orthopédique régulier au CCD et au CHU de Pointe-à-Pitre, a permis la réduction de la fréquence de l’ONTF et d’autres morbidités.

Le rappel sur la drépanocytose révèle la complexité de la maladie, la variabilité de son expression clinique et de ses complications. L’amélioration de vie des patients nécessite une prévention primaire, secondaire et tertiaire, en l’absence d’un traitement spécifique de la maladie.

La prise en charge médicale, complétée par une prévention et un traitement précoce (orthopédique ou chirurgical) telle que réalisés au CCD en Guadeloupe, a permis une réduction significative de la survenue de la nécrose de hanche et de ses complications. Pour une prévention tertiaire des complications ostéo-articulaires, nous suggérons:

- une prise en charge médicale régulière des enfants et des adultes afin de réduire les crises vaso-occlusives;

- une éducation des patients à la recherche de signes d’appel de l'ONTF et, aussi, d’autres articulations;

- un examen clinique ostéo-articulaire lors des bilans annuels et après toute crise vaso-occlusive;

- une attention particulière à l’adolescence (passage enfant-adulte), après une grossesse;

- une prise en charge précoce, orthopédique ou chirurgicale conservatrice (forage ou ostéotomie) face à une

nécrose, afin de réduire les complications invalidantes de l’ONTF.

Sickle-cell anemia is the most widespread hereditary (autosomal recessive Mendelian transmission) molecular pathology in the world. It is a public health issue in many countries, due to its severity and socio-economic impact. Only homozygous (SS) and double heterozygous (SC) subjects are affected, heterozygous (AS) subjects merely transmitting the gene S. Sickle-cell anemia is the most frequent cause of osteonecrosis of the femoral head (ONFH), a painful condition which evolves towards osteoarthritis if not treated at an early age.

Guadeloupe has a population of 450,000, 12% of whom are carriers of hemoglobin S. There are estimated to be 1,200 sickle-cell anemia sufferers, three-quarters of whom are followed in the Caribbean Sickle-Cell Center (Centre Caribéen de la Drépanocytose: CCD), which was set up in 1990. The Center provides medical care for adult patients and for children as of birth. Work has been ongoing since July 1992, in the Pointe-à-Pitre University Hospital, the CCD and the INSERM-UMR S458 research unit, focusing on:

- diagnosis of ONFH;

- bone hyperpressure measurement in ONFH and assessment of simple drilling treatment;

- the impact of early orthopedic treatment on the onset and evolution of ONFH.

The present study involved homozygous (SS) and double heterozygous (SC) adult sickle-cell anemia patients:

- a retrospective series, from 1993 to 1994 [S-1994], including 115 patients (58 SS, 57 SC) identified in 1984,

who had no medical or orthopedic care;

- a prospective series, from 1995 to 2008 [S-2008], including 215 patients (94 SS, 121 SC), with medical and orthopedic care.

MRI is the diagnostic gold-standard in ONFH, as in idiopathic necrosis. Where such modern imaging is not available, complete standard X-ray (lateral and especially false lateral) enables diagnosis to be made before deformity sets in. Surgery is indicated only for clinically symptomatic evolutive lesions on iterative clinical check-up, X-ray control, tomography, CT or MRI.

Intraosseous hyperpressure in sickle-cell ONFH shows a significant correlation with pain, in both homozygous and heterozygous patients. Pressure reduction is objectively pain-relieving, as seen after drilling, and can confirm diagnosis of ONFH at an early stage, in places where MRI is not available.

Drilling performed in the early stages of ONFH quickly arrests evolution towards osteoarthritis, with proven efficacy in grades I and II, and a certain degree of effectiveness in grade III. Over and above the pain-relief provided by decompression, drilling also enables hip replacement to be postponed, by 7.4±2.7 years. Moreover, the technique is feasible in those under-equipped regions in which sickle-cell disease is widespread.

Histologic description of radiologic ONFH stages consistently finds medullary and bone necrosis. In contrast to idiopathic lesions, sickle-cell related lesions show inflammation without any associated infection.

In the literature, the frequency of adult sickle-cell ONFH is reported to be nearly 40%, close to the 36.5% found in the S-1994 study of a non-treated population. In the S-2008 study of a population with medical and orthopedic care, ONFH frequency fell to 14.4%. The official provision of medical care and regular orthopedic follow-up in the CCD and Pointe-à-Pitre Hospital has reduced the frequency of ONFH and other morbidities.

A review of sickle-cell disease reveals its complexity: the variability of its clinical expression and associated complications. Improving patients’ quality of life requires primary, secondary and tertiary prevention, in the absence of specific treatment.

Medical care, supplemented by early prevention and treatment (orthopedic or surgical), as practiced in the Guadeloupe CCD, has significantly reduced the rates of ONFH and associated complications. We recommend the following CCD protocol for tertiary prevention of osteoarticular complications:

- regular medical care for children and adults, to reduce the incidence of vaso-occlusive crises;

- patient education in alarm signs of osteonecrosis of the femoral head and of other joints;

- systematic osteoarticular assessment at yearly check-up and after all vaso-occlusive crises;

- special focus on adolescence (child-to-adult transition) and following pregnancy;

- early care, both orthopedic and by conservative surgery (drilling or osteotomy), in case of necrosis, to reduce the rate of disabling complications of ONFH
Doctorat en Sciences médicales
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La radiochirurgie par Gamma Knife constitue une modalité thérapeutique reconnue de certaines affections cérébrales. Le traitement se base sur l’administration d’un rayonnement focalisé au niveau d’une cible intracrânienne. L’efficacité de ce traitement repose sur la délivrance d’une dose d’irradiation efficace au sein d’un volume-cible associé à la délivrance d’une dose d’irradiation négligeable à l’extérieur de ce même volume-cible. En pratique, la dose d’irradiation administrée à l’intérieur du volume-cible n’est pas distribuée de manière homogène, et la dose d’irradiation reçue par les tissus situés en-dehors du volume-cible n’est pas nécessairement faible. Notre travail est basé sur l’hypothèse que l’imperfection de la distribution de la dose d’irradiation au sein du volume-cible et en-dehors de celui-ci peut être responsable des échecs et des complications rencontrées en radiochirurgie. Dans deux modèles cliniques de traitement radiochirurgical, le schwannome vestibulaire et la névralgie du trijumeau, nous avons montré qu’il existait une relation entre les paramètres de distribution de dose d’irradiation et certains résultats du traitement radiochirurgical par Gamma Knife de ces pathologies. Nous avons développé deux modèles expérimentaux d’irradiation radiochirurgicale de rats, l’un ciblé sur le striatum et l’autre sur le nerf trijumeau, permettant d’analyser les conséquences histologiques des variations de la distribution de dose à l’intérieur du volume-cible ainsi qu’à distance de celui-ci. Nous avons démontré que la réponse radiobiologique des tissus irradiés était fortement dépendante de ce paramètre dosimétrique, et que ce dernier constituait une donnée de la planification chirurgicale aussi importante que la dose de prescription. Nous avons corrélé ces résultats avec certaines observations réalisées dans d’autres indications de traitement radiochirurgical ainsi que dans l’analyse histologique de tumeurs traitées par Gamma Knife. Ces études mettent en évidence le rôle important joué par l’optimalisation de la distribution de la dose d’irradiation dans l’amélioration des résultats cliniques du traitement radiochirurgical. Les valeurs optimales de la distribution de dose dans les différentes indications de traitement radiochirurgical doivent être recherchées, et les différentes méthodes mises à notre disposition lors de la planification dosimétrique pour améliorer la distribution de dose doivent être utilisées avec discernement pour obtenir la dosimétrie radiochirurgicale la plus parfaite possible.
Doctorat en sciences médicales
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Les métastases hépatiques du cancer colorectal (MHCR) sont fréquentes et sont associées à une mortalité significative. Ces dernières décennies, des progrès thérapeutiques importants ont permis d'en améliorer le pronostic. Plus particulièrement, le rôle des résections hépatiques s'est considérablement élargi dans la maladie métastatique limitée au foie, conduisant à un changement radical dans la prise en charge. Ceci a naturellement eu des répercussions sur l'imagerie, qui doit être très performante au niveau lésionnel, nécessitant des sensibilité et spécificité très élevées. Si les techniques modernes ont permis une amélioration très nette en termes de sensibilité, en particulier grâce aux produits de contraste hépatospécifiques et de l'imagerie pondérée en diffusion, l'amélioration de la spécificité est moins claire et moins bien évaluée. Pourtant, la spécificité est tout aussi importante dans ce contexte, où les erreurs diagnostiques sont coûteuses, avec des chirurgies inutiles en cas de faux positifs, et des résections incomplètes en cas de faux négatifs. Ces deux situations sont accompagnées d'une morbi-mortalité très importante. Le présent travail de thèse va donc explorer de nouvelles pistes dont l'objectif ultime serait d'améliorer la spécificité de l'imagerie des MHCR. La première étude confronte l'apparence des métastases d'origine colorectale en IRM de haute résolution et leur histologie sous-jacente. Cette étude originale démontre que la fibrose tumorale apparait en hypersignal T2 et la nécrose tumorale en hyposignal T2 et hypersignal T1, ce qui va à l'encontre du dogme classique. La seconde étude explore la faisabilité de la fusion d'images IRM/échographie dans l'exploration de lésions hépatiques focales chez des patients ayant un cancer colorectal. Cette étude montre qu'un nombre significatif de lésions ne peuvent être visualisées à l'échographie qu'en utilisant la fusion, ouvrant la voie à une meilleure caractérisation lésionnelle en combinant les atouts de l'échographie et de l'IRM. Enfin, la troisième étude, complétée d'une revue iconographique, analyse le comportement IRM des lésions hépatiques après injection d'un produit de contraste intravasculaire. Elle montre une accumulation progressive du contraste au sein des angiomes, mais pas dans les métastases, conduisant à des apparences très différentes sur la phase tardive. Ceci était aussi observé dans les lésions de petites tailles, ce qui devrait permettre une meilleure spécificité dans les cas difficiles
Colorectal cancer liver metastases (CRCLM) are common and result in significant mortality. During the past decades, important therapeutic advances have improved the prognosis signficantly, especially through a marked expansion of the role of hepatic resections in liverlimited metastatic disease, leading to a radical change in management. This was naturally accompanied by an equally radical change in the imaging paradigm, now centered at the lesion level and not at the patient level, requiring very high sensitivity and specificity. While modern techniques have allowed a significant improvement in terms of sensitivity, especially through the use of hepatospecific contrast agents and diffusion imaging, the benefits in term of specificity are less clear, with only few studies focusing on and reporting the specificity of the techniques. However, specificity is equally important in this context, where diagnostic errors are costly, resulting either in unnecessary surgeries in case of false positives or in incomplete resections in case of false negatives. In this setting, our thesis will examine the results of three studies, which objective is to offer possible solutions to better understand the imaging of metastases and improve the specificity of liver imaging of CRCLM. The first study analyzes the association between high resolution MRI appearance of CRCLM and their underlying histology, showing that tumor fibrosis was in hypersignal on T2 Weighted Imaging while tumor necrosis was in hyposignal on T2 Weighted Imaging and hypersignal on T1 Weighted Imaging, which goes against the classical teaching about these lesions. The second study assesses the feasibility of using an MRI/Ultrasound fusion system in the exploration of liver lesions in patients with colorectal cancer. This study shows that more lesions were detected with ultrasound when using the fusion system, suggesting that a fusion system may allow a better characterization of lesions by combining the complementary information of MRI and ultrasound. Finally, the third study and its accompanying pictorial essay, explored the behavior of liver lesions after injection of an intravascular contrast agent. The main finding of this study was that hemangioma were accumulating the contrast over time while metastases were not, a key differentiating feature. This finding was found even in small lesions, often difficult to diagnose, suggesting that using such contrast in the exploration of liver lesions in patients with CRCLM would result in a higher specificity of the method

Cette étude à pour objectif de maîtriser les conditions de culture et de production toxinique chez Karenia selliformis et Alexandrium ostenfeldii dans le but de réaliser des contaminations expérimentales indépendamment du caractère aléatoire des proliférations toxiques en zones côtières. Ce travail vise également à étudier l'impact de l'alimentation sur la détoxification artificielle de la palourde Ruditapes decussatus contaminée par des gymnodimines et de l'huître Crassostrea gigas contaminées par des spirolides et enfin d'étudier l'impact physiologique de ces micro-algues toxiques au niveau des organes accumulateurs des coquillages. Dans un premier temps, il a été mis en évidence que les performances de croissance de K. selliformis (taux de croissance et concentration maximale) sont obtenues à une température de 22°C pour une salinité de 36 psu en utilisant le milieu f/2 alors que celles d'A. ostenfeldii sont obtenues à une température de 16°C pour une salinité de 35 psu en utilisant le milieu L1. Le contenu en gymnodimine dans les cellules de K. selliformis augmente en fonction de l'âge de la culture alors que le contenu en spirolide diminue au cours de la croissance cellulaire d'A. ostenfeldii plus particulièrement lors de la culture en photobioréacteur de 100 l. Dans un deuxième temps, des études expérimentales portant sur l'interaction des micro-algues toxiques avec les mollusques ont permis d'apporter des connaissances nouvelles sur le devenir des imines cycliques après contamination et lors de la détoxification. Il a ainsi été mis en évidence i) une accumulation majoritaire des GYMs et des SPXs au niveau des glandes digestives des palourdes et des huîtres ii) une accélération des cinétiques de détoxification lors de l'ajout de l'alimentation. Dans un troisième temps, les essais portant sur la contamination de C. gigas par A. ostenfeldii ont permis de déterminer i) une altération des diverticules digestifs consistant en une réduction de l'épaisseur de la paroi épithéliale et en une augmentation de la surface de la lumière des diverticules digestifs ii) une réaction inflammatoire dans la glande digestive de certains individus contaminés se caractérisant par une agglutination massive d'hémocytes autour de différents organes de la glande digestive: l'estomac, l'intestin ainsi que les conduits et tubules digestifs. Dans le cas des contaminations naturelles et expérimentales des palourdes les analyses histologiques réalisées n'ont pas permis de mettre en évidence des signes d'altération de la glande digestive comme dans le cas des les huîtres contaminées par A. ostenfeldii.

L'histologie tridimensionnelle (3D) est un nouvel outil avancé de cancérologie. L'ensemble du profil chimique et des caractéristiques physiologiques d'un tissu est essentiel pour comprendre la logique du développement d'une pathologie. Cependant, il n'existe aucune technique analytique, in vivo ou histologique, capable de découvrir de telles caractéristiques anormales et de fournir une distribution3D à une résolution microscopique. Nous présentons ici une méthode unique de microscopie infrarouge (IR) à haut débit combinant une correction d'image automatisée et une analyse ultérieure des données spectrales pour la reconstruction d'image 3D-IR. Nous avons effectué l'analyse spectrale d'un organe complet pour un petit modèle animal, un cerveau de souris avec une tumeur de gliome implantée. L'image 3D-IR est reconstruite à partir de 370 coupes de tissus consécutives et corrigée à l'aide du tomogramme à rayons X de l'organe pour une analyse quantitative précise du contenu chimique. Une matrice 3D de spectres IR 89 x 106 est générée, ce qui nous permet de séparer la masse tumorale des tissus cérébraux sains en fonction de divers paramètres anatomiques,chimiques et métaboliques. Nous démontrons pour la première fois que des paramètres métaboliques quantitatifs (glucose, glycogène et lactate) peuvent être extraits et reconstruits en 3D à partir des spectres IR pour la caractérisation du métabolisme cérébral / tumoral (évaluation de l'effet de Warburg dans les tumeurs). Notre méthode peut être davantage exploitée en recherchant l'ensemble du profil spectral, en distinguant différents points de repère anatomiques dans le cerveau.Nous le démontrons par la reconstruction du corps calleux et de la région des noyaux gris centraux du cerveau
Three-dimensional (3D) histology is a new advanced tool for cancerology. The whole chemical profile and physiological characteristics of a tissue is essential to understand the rationale of pathology development. However, there is no analytical technique, in vivo or histological, that is able to discover such abnormal features and provide a 3D distribution at microscopic resolution.Here, we introduce a unique high- throughput infrared (IR) microscopy method that combines automated image correction and subsequent spectral data analysis for 3D-IR image reconstruction. I performed spectral analysis of a complete organ for a small animal model, a mouse brain with animplanted glioma tumor. The 3D-IR image is reconstructed from 370 consecutive tissue sectionsand corrected using the X-ray tomogram of the organ for an accurate quantitative analysis of thechemical content. A 3D matrix of 89 x 106 IR spectra is generated, allowing us to separate the tumor mass from healthy brain tissues based on various anatomical, chemical, and metabolic parameters. I demonstrate for the first time that quantitative metabolic parameters (glucose, glycogen and lactate) can be extracted and reconstructed in 3D from the IR spectra for the characterization of the brain vs. tumor metabolism (assessing the Warburg effect in tumors). Our method can be further exploited by searching for the whole spectral profile, discriminating different anatomical landmarks in the brain. I demonstrate this by the reconstruction of the corpus callosum and basal ganglia region of the brain

La cryoconservation de tissu ovarien peut être proposée, avant traitements hautement gonadotoxiques, à des patientes afin de préserver leur fertilité. L'autogreffe de tissu ovarien est actuellement la seule méthode de réutilisation du tissu ovarien disponible, mais en cas de pathologie néoplasique, elle présente un risque de réintroduction d'éventuelles cellules malignes via le greffon. L'objectif de ce travail a été de développer une méthode pour détecter la maladie résiduelle (MRD) dans le tissu ovarien par cytométrie en flux multicouleurs (CMF) en cas de leucémie aiguë. Une technique de dissociation de cortex ovarien a été mise au point à partir de tissu ovarien de référence provenant de résections percoelioscopiques. Un modèle expérimental de détection de la MRD a été validé et consistait à ajouter des cellules de leucémie aiguë lymphoblastique (LAL) ou myéloïde (LAM) à une suspension de cellules ovariennes isolées de référence. La méthode a ensuite été utilisée pour rechercher la MRD dans le tissu ovarien cryoconservé de 11 patientes atteintes de leucémie aiguë (7 LAL et 4 LAM).Le modèle expérimental a permis de valider une sensibilité de 10"4 et une spécificité élevée tant pour les LAL que pour les LAM. Lorsqu'un marqueur moléculaire était disponible pour la recherche de la MRD, nous avons observé une bonne corrélation entre la CMF et la PCR quantitative. La détection par CMF de la MRD dans le tissu ovarien des patientes leucémiques était positive chez 3 des 11 patientes étudiées.Cette technique est essentielle pour évaluer le risque carcinologique avant de proposer la réutilisation du tissu ovarien cryoconservé par technique d'autogreffe
Ovarian cryopreservation together with autograft of frozen/thawed ovarian tissue is a real option to preserve and restorefertility in cancer patients. However in cases of leukemia, there is a real concern regarding the presence of metastaticcells in the ovarian tissue, which could lead to the recurrence of the primary disease. The aim was to validate multicolorflow cytometry (MFC) as an original technique for minimal residual disease (MRD) detection in ovarian cortex fromacute leukemia patients.We developed an experimental model which consisted in adding serial dilutions of leukemic cells into isolated ovariancell suspensions obtained from healthy cortex. The modelization was validated for acute lymphoblastic leukemia (ALL)and acute myeloid leukemia (AML). Then the method was applied to MRD detection of leukemic cells in cryopreservedovarian cortex from 11 leukemia patients (7 ALL and 4 AML).This experimental model made it possible to obtain a high specificity and a robust sensitivity of 10~4 for MRD detectionby MFC for both types of acute leukemic cells. When a molecular marker was available, we observed a good correlationbetween CMF and quantitative PCR. Ovarian MRD was positive by MFC in one T-ALL and 2 AML patients.MRD detection in the ovarian cortex is essential to evaluate the risk of cancer reseeding before ovarian tissue autograft

Objectifs: réaliser une étude anatomique et anthropologique de l’os hyoïde en utilisant les moyens modernes de reconstruction 3D et discuter les applications cliniques potentielles notamment en cancérologie. Méthode : L’étude a été réalisée à partir d’une analyse de 180 os hyoïdes dont 88 ont été prélevés sur cadavres (groupe 1) et 92 analysés à partir d’examens tomodensitométriques pratiqués sur des sujets vivants (groupe 2). Une analyse métrique ainsi qu’une analyse de morphométrie géométrique ont été réalisées pour chaque groupe. Les 2 groupes ont ensuite été comparés afin d’évaluer l’influence des muscles sur la morphologie de l’os hyoïde. Dans un second temps, nous avons appliqué cette méthodologie à une série de 24 patients opérés de laryngectomie partielle. Résultats : Nous avons montré qu’il existait une importante hétérogénéité morphologique entre les os hyoïdes et que celle-ci était étroitement liée au sexe, à la taille et au poids des individus. En effet, la longueur et la largeur de l’os hyoïde étaient significativement plus importantes chez les hommes que chez les femmes (39,08 vs. 32,50 mm, p=0,033 et 42,29 vs. 38,61 mm, p=0,003). Par ailleurs, l’angle formé par les deux grandes cornes (angle alpha) était plus large chez les femmes (44,09 vs. 38,78 p=0,007). De plus, la longueur de l’os hyoïde était corrélée de façon positive avec la taille (coefficient de corrélation de Pearson r=0,533, p=0,01) et le poids des sujets (r=0,497, p=0,01). Des différences métriques significatives ont aussi été retrouvées entre les os hyoïdes secs et les os des sujets vivants
Objectives: To perform an anatomical and anthropological study of the hyoid bone using modern 3D reconstruction tools and to discuss potential applications in clinical practice. Methods: The study was conducted on 88 intact hyoid bones taken from cadavers during forensic autopsies (group 1) and on 92 from CT-scan images of living adult subjects (group 2). Three-dimensional reconstructions were created from CT-scan images using Amira 5.3.3® software. An anatomical and anthropological study of hyoid bones was carried out using metric and morphologic analysis. A comparison was performed between groups 1 and 2 in order to evaluate the influence of muscle traction on hyoid bone shape. In a second step, this methodology was applied to 24 patients operated on for partial laryngectomy. Results: Characteristics of the hyoid bone were highly heterogeneous and were closely linked with the sex, height and weight of individuals. Length and width were significantly greater in men than in women (39.08 vs. 32.50 mm, p=0.033 and 42.29 vs. 38.61 mm, p=0.003) whereas the angle between the greater horns was larger in females (44.09 vs. 38.78 p=0.007). There was a significant positive correlation between the height (Pearson coefficient correlation r=0.533, p=0.01) and weight (r=0.497, p=0.01) of subjects and the length of the hyoid bone. Significant metric differences were shown between group 1 and group 2. In patients operated on for partial laryngectomy, hyoid bones could be classified into 3 types (A, B and C) according to their morphology. Conclusion: This very reproducible methodology is of importance because it may lead to clinical studies, particularly in head and neck cancer

Traumatic brain injury (TBI) is a leading cause of disability worldwide. Annually, 150 to 200/1,000,000 people become disabled as a result of brain trauma. Axonal degeneration is a critical, early event following TBI of all severities but whether axon degeneration is a driver of TBI remains unclear. Molecular pathways underlying the pathology of TBI have not been defined and there is no efficacious treatment for TBI. Despite this significant societal impact, surprisingly little is known about the molecular mechanisms that actively drive axon degeneration in any context and particularly following TBI. Although severe brain injury may cause immediate disruption of axons (primary axotomy), it is now recognized that the most frequent form of traumatic axonal injury (TAI) is mediated by a cascade of events that ultimately result in secondary axonal disconnection (secondary axotomy) within hours to days. Proposed mechanisms include immediate post-traumatic cytoskeletal destabilization as a direct result of mechanical breakage of microtubules, as well as catastrophic local calcium dysregulation resulting in microtubule depolymerization, impaired axonal transport, unmitigated accumulation of cargoes, local axonal swelling, and finally disconnection. The portion of the axon that is distal to the axotomy site remains initially morphologically intact. However, it undergoes sudden rapid fragmentation along its full distal length ~72 h after the original axotomy, a process termed Wallerian degeneration. Remarkably, mice mutant for the Wallerian degeneration slow (Wlds) protein exhibit ~tenfold (for 2–3 weeks) suppressed Wallerian degeneration. Yet, pharmacological replication of the Wlds mechanism has proven difficult. Further, no one has studied whether Wlds protects from TAI. Lastly, owing to Wlds presumed gain-of-function and its absence in wild-type animals, direct evidence in support of a putative endogenous axon death signaling pathway is lacking, which is critical to identify original treatment targets and the development of viable therapeutic approaches. Novel insight into the pathophysiology of Wallerian degeneration was gained by the discovery that mutant Drosophila flies lacking dSarm (sterile a/Armadillo/Toll-Interleukin receptor homology domain protein) cell-autonomously recapitulated the Wlds phenotype. The pro-degenerative function of the dSarm gene (and its mouse homolog Sarm1) is widespread in mammals as shown by in vitro protection of superior cervical ganglion, dorsal root ganglion, and cortical neuron axons, as well as remarkable in-vivo long-term survival (>2 weeks) of transected sciatic mouse Sarm1 null axons. Although the molecular mechanism of function remains to be clarified, its discovery provides direct evidence that Sarm1 is the first endogenous gene required for Wallerian degeneration, driving a highly conserved genetic axon death program. The central goals of this thesis were to determine (1) whether post-traumatic axonal integrity is preserved in mice lacking Sarm1, and (2) whether loss of Sarm1 is associated with improved functional outcome after TBI. I show that mice lacking the mouse Toll receptor adaptor Sarm1 gene demonstrate multiple improved TBI-associated phenotypes after injury in a closed-head mild TBI model. Sarm1-/- mice developed fewer beta amyloid precursor protein (βAPP) aggregates in axons of the corpus callosum after TBI as compared to Sarm1+/+ mice. Furthermore, mice lacking Sarm1 had reduced plasma concentrations of the phosphorylated axonal neurofilament subunit H, indicating that axonal integrity is maintained after TBI. Strikingly, whereas wild type mice exhibited a number of behavioral deficits after TBI, I observed a strong, early preservation of neurological function in Sarm1-/- animals. Finally, using in vivo proton magnetic resonance spectroscopy, I found tissue signatures consistent with substantially preserved neuronal energy metabolism in Sarm1-/- mice compared to controls immediately following TBI. My results indicate that the Sarm1-mediated prodegenerative pathway promotes pathogenesis in TBI and suggest that anti-Sarm1 therapeutics are a viable approach for preserving neurological function after TBI.

Introduction : L’élastographie shear wave (ESW) est une technique récente d’échographie qui évalue quantitativement la dureté des tissus et permet d’améliorer la caractérisation des lésions mammaires. Comme toute nouvelle technique d’imagerie, l’ESW nécessite une validation préclinique pour définir les conditions d’utilisations et établir les limites des champs d’applications dans lesquelles la technique pourra être considérée comme valide. Matériels et méthodes : Dans une première partie effectuée au laboratoire de recherche en Imagerie nous avons étudié les éléments histologiques sous tendant l’image d’ESW sur un modèle de cancer du sein implanté chez la souris, au cours de sa croissance puis sous traitement. Dans une deuxième partie, nous avons étudié chez des patientes le rôle de la compression manuelle en ESW pour la caractérisation des lésions mammaires. Dans une dernière partie, effectuée en collaboration avec une équipe de l’Institut Langevin Ondes et Images, nous avons étudié la faisabilité d’un nouveau paramètre, le module de cisaillement non linéaire pour l’analyse des lésions mammaires. Résultats : Au laboratoire, nous avons établi des corrélations entre la dureté mesurée en élastographie et les caractéristiques histologiques des tumeurs, y compris sous traitement. Nous avons montré que la fibrose était associée à une dureté élevée et la nécrose à une dureté moindre. Notre étude clinique a montré qu’une compression manuelle minimale était nécessaire pour obtenir de bonnes performances de l’ESW et qu’une pression trop élevée devait être évitée. Enfin nous avons montré la faisabilité en imagerie mammaire d’un nouveau paramètre quantitatif obtenu en élastographie shear wave : le module de cisaillement non linéaire. Conclusion : A partir de travail de thèse, une meilleure compréhension de la part des éléments biologiques et techniques en ESW du sein est possible et des recommandations pour l’utilisation clinique peuvent être formulées. Nos observations cliniques ont entrainé la mise au point d’un nouveau paramètre diagnostique quantitatif : le module de cisaillement non linéaire
Introduction: Shear Wave Elastography (SWE) is a recent ultrasound technique assessing quantitatively tissue stiffness and improving breast lesions characterization. As every new imaging technique, SWE requires a pre clinical validation in order to define in which conditions it should be used and precise the applications for which the technique is validated. Materials and methods: First, in a research lab we have investigated the pathological features underlying SWE image in a breast cancer model implanted in mice, during tumor growth and under therapy. Secondly, we have studied in patients the role of manual compression in SWE for the characterization of breast lesions. Finally, in collaboration with on team from Institut Langevin Ondes et Images, we have studied the feasibility of a new parameter, the non-linear modulus, for breast lesion assessment. Results: in the research lab, we have shown correlations between stiffness as measured with SWE and pathological features of tumors, even on treatment. We have shown that fibrosis was associated with high stiffness values and necrosis with lowers. Our clinical study, showed that a minimal manual compression was required for optimal performance of SWE and that strong compression should be avoided. Finally, we demonstrated feasibility of a new parameter, derived from SWE, the non-linear modulus. Conclusion: Our work provides a better understanding of biological and technical elements of SWE. On the basis of our results, new recommendations may be made for the use of SWE in clinical practice. From our clinical findings, we developed a new quantitative parameter, which may be useful for the diagnosis of breast lesions, the non-linear modulus

La fibrilline-1, composant majeur des microfibrilles et second composant majeur des fibres élastiques, est une glycoprotéine dont la mutation du gène chez l'humain est responsable du syndrome de Marfan, caractérisé par des anévrismes et des dissections aortiques. Dans ce travail de thèse, nous avons étudié d'une part le rôle de la fibrilline-1 dans la physiologie des cellules endothéliales vasculaires humaines et d'autre part la conséquence du déficit quantitatif de la fibrilline-1 sur la structure et la fonction du système cardiovasculaire au cours du vieillissement chez la souris. Le fragment de fibrilline-1 "PF14" induit une signalisation calcique via les intégrines α5β1 et αvβ3, l'activation de la phospholipase C et la mobilisation des réserves intracellulaires de calcium, ainsi que la prolifération et la migration des cellules endothéliales humaines. La déficience quantitative sévère ou totale de la fibrilline-1 entraîne une létalité chez la souris dans les deux semaines après la naissance alors que celle, partielle, due à la délétion hétérozygote hypomorphique des exons 19 à 24 du gène de la fibrilline-1 (délétion mgΔ) n'affecte pas la longévité des souris. Les souris Fbn-1+/mgΔ présentent une hypertrophie cardiaque et une hypotension ainsi que des anévrismes aortiques qui deviennent plus fréquents avec l'âge. La paroi aortique de ces souris présente des altérations structurales (fragmentations des lames élastiques), biomécaniques (l'augmentation de la rigidité) et de la vasomotricité, qui s'accentuent avec l'âge. Nos résultats suggèrent que la déficience quantitative de la fibrilline-1 pourrait altérer la signalisation que cette protéine déclenche normalement dans les cellules endothéliales dès la phase de morphogénèse artérielle, et induire en conséquence une pathologie anévrismale de la paroi aortique au cours du vieillissement. Les effets opposés des déficiences quantitatives en fibrilline-1 et en élastine sur la fonction vasculaire suggèrent des rôles opposés pour ces deux composants majeurs des fibres élastiques. Ce travail permet par ailleurs de valider les souris Fbn-1+/mgΔ, tant sur le plan structural que fonctionnel, comme modèle du syndrome de Marfan.

Dans ce travail, nous démontrons que STIM1, un senseur calcique activé par la déplétion du Ca2+ intracellulaire du réticulum endoplasmique, est indispensable pour la signalisation calcique et la préférence oro-sensorielle du gras. Nous observons que l'acide linoléique (LA), en activant les phospholipases A2 via CD36, produit de l'acide arachidonique (AA) et de la lyso-phosphatidylcholine (lyso-PC). Cette activation déclenche un influx calcique dans les cellules CD36-positives, et induit la production du facteur CIF (Ca2+ Influx Factor). CIF, AA et lyso-PC exercent différentes actions sur l'ouverture des canaux SOC (Stored Operated Calcium Channel) constitués de protéines Orai et contrôlés par STIM1. Par ailleurs, les souris au phénotype Stim1-/- perdent la préférence spontanée pour les lipides et la libération de la sérotonine à partir des cellules gustatives dans le milieu extracellulaire chez les animaux sauvages. Nous demontrons aussi que la signalisation calcique médiée via CD36 est doublement modulée lors de l'obésité. L'augmentation de la [Ca2+]i dans les cellules gustatives observée chez le Psammomys obesus, un modèle d'obésité nutritionelle, est fortement diminuée chez les souris rendues obèses par un regime hyperlipidique. Nous avons constaté également que l'interaction de LA avec le CD36 induit l'activation des MAP Kinases de la voie MEK1/2/ERK1/2/Elk-1 qui est non seulement à l'origine de l'activation des aires cérébrales telles que le NTS, le noyau arqué, l'hippocampe mais aussi indispensable pour la préférence spontanée pour les lipides alimentaires. Nos résultats suggèrent pour la prémière fois, que la voie ERK1/2 des MAPK et la signalisation calcique lipidique controlée par STIM1 sont impliquées dans la perception oro-gustative des lipides

Metallic implants called stents are an important part of the treatment of coronary heart disease. While clinical trials are excellent indicators of outcomes, microscopic evaluation of the host tissue response to the implant is required to assess their safety and efficacy. However, the evaluation of human autopsy tissue containing metal implants presents unique challenges in order to obtain the best results. We used integrated microscopy techniques incorporating microCT and novel plastic histology techniques to demonstrate its effectiveness on human stented vessels obtained at autopsy. A total of seven cases are demonstrated where our analysis techniques were able to elucidate the pathogenesis of the host response and identify the specific cause of the complications with the stented vessel seen clinically. These techniques are more cost effective and efficient than other techniques currently in use, which could enable them to be used as part of routine autopsy evaluation. The expansion of the pool of stented vessels able to be analyzed to include the often overlooked large population of autopsy cases could provide an enormous amount of data to guide future clinical trials and improve patient care.