Dissertations / Theses on the topic 'Digestive system surgical procedures'

Os desfechos clínicos e oncológicos dos pacientes submetidos à ressecção endoscópica do câncer gástrico precoce (CGP), considerando os critérios de indicação, comparados à cirurgia, não foram relatados em revisões sistemáticas. A pesquisa foi desenvolvida para estabelecer os desfechos de curto e longo prazos da ressecção endoscópica comparada à cirurgia no tratamento do CGP, elevando as informações para o nível de evidência 2a, melhor respaldando a prática clínica. A revisão sistemática com metanálises foi procedida utilizando-se as bases Medline, Embase, Cochrane, LILACS, Scopus e CINAHL. Onze coortes retrospectivas foram selecionadas para análise qualitativa e quantitativa. Todos os estudos incluem pacientes com CGP e comparam os desfechos nos dois braços. Os dados envolveram 2654 pacientes que preenchiam os critérios absolutos ou expandidos para ressecção endoscópica. Diferentes modalidades de tratamento endoscópico foram avaliadas, principalmente os procedimentos de ressecção, como endoscopic mucosal resection (EMR) e endoscopic submucosal dissection (ESD). As informações basearam-se nas características dos participantes, critérios de inclusão e exclusão, tipos de intervenções e desfechos (diferentes taxas de sobrevida, eventos adversos, ressecção completa, recorrência e mortalidade). As análises dos riscos absolutos dos desfechos foram feitas com o software RevMan, computando-se as diferenças de risco (DR) das variáveis dicotômicas. Dados de DR e intervalo de confiança de 95% (IC) foram calculados utilizando-se o teste de Mantel-Haenszel e a inconsistência foi qualificada e reportada em ?2 e método Higgins (I2). A análise de sensibilidade foi feita quando a heterogeneidade era maior que 50%. Todas as análises basearam-se inicialmente no modelo de efeito fixo. Dados de sobrevida de 3 anos estavam disponíveis em seis estudos (n = 1197). Não houve DR após os dois tratamentos (DR = 0,01, IC 95% = -0,02 a 0,05). A sobrevida de 5 anos (n = 2310) não demonstrou diferença significativa entre os grupos analisados (DR = 0,01, IC 95% = -0,01 a 0,03). A avaliação de 551 pacientes não evidenciou desigualdade na sobrevida de 10 anos entre as diferentes abordagens (DR = -0,02, IC 95% = -0,15 a 0,10). Dados de complicação estavam presentes em oito estudos (n = 2439), e diferença significativa foi detectada (DR = -0,08, IC 95% = -0,10 a -0,05), demonstrando melhores resultados com a endoscopia. As taxas de ressecção completa foram analisadas em 536 pacientes. Evidenciou-se diferença significativa entre o tratamento endoscópico e cirúrgico (DR = -0,13, IC 95% = -0,17 a -0,09), validando melhores resultados no último grupo. A recorrência foi avaliada em cinco pesquisas (n = 1331) e não houve diferença entre as duas formas de terapêutica (DR = 0,01, IC 95% = -0,00 a 0,02). As taxas de mortalidade foram obtidas de quatro estudos (n = 1107), e não se evidenciou diferença entre os grupos envolvidos (DR = -0,01, IC 95% = -0,02 a 0,00). Conclui-se que as taxas de sobrevida de 3, 5 e 10 anos, recorrência e mortalidade são semelhantes em ambos os grupos. Considerando-se as taxas de complicação, a abordagem endoscópica confere resultados mais apropriados e, analisando-se as taxas de ressecção completa, ela é inferior à cirurgia
Clinical and oncological outcomes of endoscopic resection of early gastric cancer (EGC), considering the indication criteria, compared to surgery, have not been reported in systematic reviews. To address the short- and long-term outcomes of endoscopic resection compared to surgery in the treatment of EGC, a systematic review was performed, establishing the available data to an unpublished 2a strength of evidence, better handling clinical practice. A systematic review and meta-analysis using Medline, Embase, Cochrane, LILACS, Scopus and CINAHL databases were done. Eleven retrospective cohort studies were selected to quantitative and qualitative synthesis. All studies included patients diagnosed with EGC that compared outcomes considering endoscopic treatment and surgery. The included records involved 2654 patients with EGC that filled the standard or expanded indications for endoscopic resection. Different endoscopic treatment modalities were analyzed, mainly mucosal resection procedures such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), compared to surgery. Information of the selected studies was extracted on characteristics of trial participants, inclusion and exclusion criteria, types of interventions and outcomes (different survival rates, adverse events, complete resection, recurrence and mortality rates). The analysis of the absolute risks of the outcomes was performed using the software RevMan, by computing risk differences (RD) of dichotomous variables. Data on RD and 95% confidence interval (CI) for each outcome were calculated using the Mantel-Haenszel test and inconsistency was qualified and reported in X2 and the Higgins method (I2). Sensitivity analysis was performed when heterogeneity was higher than 50%. All pooled analyses were initially based on fixed-effects model. Three-year survival data were available for six studies (n = 1197). There were no RD in 3-year survival data after endoscopic and surgical treatment of EGC (RD = 0.01, 95% CI = -0.02 to 0.05). Five-year survival data (n = 2310) showed no evidence of a difference between the two groups (RD = 0.01, 95% CI = -0.01 to 0.03). The data analysis, in 551 patients, showed no difference in 10-year survival rates between the approaches (RD = -0.02 and 95% CI = -0.15 to 0.10). Complication data were identified in eight studies (n = 2439). A significant difference was detected (RD = -0.08, 95% CI = -0.10 to -0.05), demonstrating better results with endoscopic approach. Complete resection data was analyzed in 536 patients. It showed significant difference in complete resection rates between endoscopic and surgical treatment of EGC (RD = -0.13, 95% CI = -0.17 to -0.09), exhibiting improved results in the surgical group. Recurrence data were analyzed in five studies (n = 1331) and there was no difference between the approaches (RD = 0.01, 95% CI = -0.00 to 0.02). Mortality data were obtained in four studies (n = 1107), and there was no difference between treatment modalities (RD = -0.01, 95% CI = -0.02 to 0.00). This systematic review concludes that 3-, 5- and 10-year survival, recurrence and mortality rates are similar for both groups. Considering procedure-related complication rates, endoscopic approach achieves significantly better results and, analyzing complete resection data, it is considered worse than surgery

No presente estudo, 30 pacientes, do sexo masculino com idade mediana de 29 anos, portadores de hérnias inguinais / inguino-escrotais, unilaterais, indiretas e primárias, sem encarceramento ou estrangulamento, foram submetidos à hernioplastia inguinal, por meio de inguinotomia, sob raqui-anestesia em regime de internação hospitalar. A técnica de correção utilizada foi a de Bassini modificada, sendo que estas modificações repousam no tipo da incisão, abordagem da fáscia transversalis e no reforço da parede posterior do canal inguinal. Os objetivos foram os de avaliar os resultados do pós-operatório mediato quanto aos eventos: intensidade e duração da dor pós-operatória e o tempo de retorno às atividades normais, estabelecendo assim a duração maior ou menor do período de convalescença. Das hérnias operadas 33,33% e 66,67% foram classificadas no intra-operatório como tipos I e II de Nyhus, respectivamente. A duração da cirurgia variou entre 45 e 85 minutos, com média de 66,46 minutos e mediana de 66,5 minutos. A permanência hospitalar foi menor que 24 horas. O índice de mortalidade foi nulo e o seguimento foi feito no 10º e 30° dias de pós-operatório. A intensidade média da dor pós-operatória atingiu seu pico máximo no 1º dia, alcançando 2,93 na escala analógica decimal, sendo que a partir do 5° dia de pós-operatório se tornou insignificante. O retorno às atividades habituais e sociais se deu em um período médio de 5,34 dias. O tempo de retorno ao trabalho alcançou a média de 11,23 dias e mediana de 5 dias. Observou-se complicação leve em dois pacientes (6,67%), que apresentaram edema de bolsa escrotal de rápida resolução. Não se observou complicações infecciosas apesar do não uso de antimicrobianos. A análise dos dados obtidos permite concluir que o procedimento é exeqüível, com boa aceitação por parte dos pacientes, apresentando resultados comparáveis aos obtidos na literatura
In the present study, 30 patients, of the male sex, with an average age of 29, victims of inguinal hernias/ inguino-scrotum, unilateral, indirect and primaries, without confinement or strangulation, were submitted to inguinal hernioplasty, thru inguinotomy, under rachianesthesia on a regimen as hospital in--patients. The correction technique used was the modified- Bassini, since these modifications lie in the kind of incision, approaching of the fascia transversalis and in the reinforcement of the posterior wall of the inguinal duct. The purposes were of evaluating the mediate post-operative results as to the events: intensity and duration of the post-operative pain in the period of time of return to the normal activities, thus determining the longer or shorter duration of the recovery period. Among the operated hernias 33.33% and 66.67% they were classified in the intra-operative as types I and II of Nyhus, respectively. The duration of the surgery varied between 45 and 85 minutes, with an average of 66.46 minutes and median of 66.5 minutes. The in-patients stay in the hospital was less than 24 hours. The mortality rate was null and the follow up was made on the 10th and 30th days of the post operative. The average intensity of the post-operative pain reached its appex on the 1st day, reaching 2.93 in the decimal analogical scale, and as of the 5th day of the post-operative it became insignificant. The return both to the usual and social activities happened in an average period of time of 5.34 days. The period of time of returning to work reached an average of 11.23 days and a median of 5 days. A slight complication was observed in two patients (6.67%), who had edema in the scrotum pouch of fast solution. No infectious complications were detected in spite of not using any anti-microbians. The analysis of the data obtained allow to conclude that the procedure is feasible, with good approval on the part of the patients, presenting results comparable to the ones obtained in the literature

Background: Recent national trends and distribution of ileal pouch-anal anastomosis (IPAA) procedures for patients with ulcerative colitis (UC) are unknown. We examined the frequency of use of elective IPAA procedures among patients with UC and the distribution of IPAA procedures across more than 140 U.S. academic medical centers and their affiliates. Methods: Data were obtained from the University HealthSystem Consortium for patients with a primary diagnosis of UC admitted electively between 2012 and 2015. Results: The mean age of the study population (n=6,875) was 43 years and 57% were men. Among these, one-third (n=2,307) underwent an IPAA, while two-thirds (n=4,568) underwent colectomy, proctectomy, proctocolectomy or other procedures. The proportion of IPAA cases among all elective admissions was relatively stable at 33-35% during the years under study. A total of 131 hospitals, out of 279 hospitals participating in the UHC, performed IPAA. The median number of IPAA cases performed annually was 1.9 [IQR 0.8 – 4.3]. Nearly one half (48%) of these cases were performed by the top ten hospitals. Overall, only a total of 30 centers performed ³ five elective IPAA cases annually. Conclusions: Although the frequency of elective IPAA surgery in recent years has been stable, nearly one half of all IPAA cases was performed at ten hospitals. The concentration of IPAA cases at high-volume centers, and the steady number of cases performed annually, have potential implications for fellowship training, patient clinical outcomes and access to care.

Hepatitis C Virus (HCV) is the primary cause of liver transplantation due to its chronic nature in up to eighty percent of infected cases. Around 3 percent of the world’s population is infected with HCV. Treatment for HCV is a combined Ribavirin and interferon-α (IFN-α) therapy effective in only fifty to eighty percent of patients depending on HCV genotype. The growing health concern with this disease is the lack of a cure despite liver transplantation. HCV targets hepatocytes, liver cells, but is not cytolytic. HCV has been shown to induce end stage liver disease through sustained inflammation from the host’s immune system in the liver. One of the key dilemmas in HCV research and the search for fully effective treatments or vaccines is the lack of animal models. HCV infectivity and disease is limited to primates, most specifically to humans, which cannot be fully replicated in any other living being. The mechanisms for HCV evasion or activation of the immune system are complex, many and discoveries within this field are crucial to overcoming this destructive hepatic infection. Toll-like receptors (TLR) are cellular activators of the innate immune system that have been a target of HCV. Activated TLRs trigger both the inflammatory and anti-viral pathways to produce inflammatory cytokines and interferons. HCV proteins have been reported to activate a number of TLRs in a variety of cell types. In order to identify possible targets of HCV within the TLR family, we first characterized TLR presence and function in both human hepatic carcinoma cell lines and purified primary human hepatocytes. RNA from TLRs 1-10 was observed to varying degrees in both the hepatoma cell lines and the primary hepatocytes. We show the extracellular and/or intracellular presence of TLR2, TLR1, TLR3 and TLR7 proteins in hepatoma cell lines. TLR3 and TLR7 are located within the endosome and recognize viral RNA products. We recently reported that TLR2-mediated innate immune signaling pathways are activated by HCV core and NS3 proteins. TLR2 activation requires homo- or heterodimerization with either TLR1 or TLR6. We show NF-κB activation in hepatoma cells by TLR2/1, TLR2/6 ligand and HCV protein stimulation. In primary hepatocytes, HCV proteins induced both IL-8 and IL-6 production. We also show that primary hepatocytes initiate a Type 1 IFN response in addition to IL-8 and IL-6 production upon stimulation with a TLR7/8 ligand. Human hepatoma and primary hepatocytes are responsive to TLR2, TLR1, TLR6, TLR7/8 ligands and HCV proteins. Activation of these TLRs may contribute to the inflammatory mediated destruction caused by HCV or could be targets of HCV contributing to its immune evasion. We found previously that hepatoma cells and primary hepatocytes are responsive to TLR2 ligands and HCV proteins. We also reported that TLR2 is activated by HCV proteins. Here we aimed to determine whether TLR2 coreceptors participated in cellular activation by HCV core or NS3 proteins. By designing siRNAs targeted to TLR2, TLR1 and TLR6, we showed that knockdown of each of these receptors impairs pro- and anti-inflammatory cytokine activation by TLR-specific ligands as well as by HCV core and NS3 proteins in Human Embryonic Kidney cells (HEK/TLR2) and in primary human macrophages. We found that HCV core and NS3 proteins induced TNF-α and IL-10 production in human monocyte-derived macrophages, which was impaired by TLR2, TLR1 and TLR6 knockdown. Contrary to human data, results from TLR2, TLR1 or TLR6 knockout mice indicated that the absence of TLR2 and its coreceptor TLR6, but not TLR1, prevented the HCV core and NS3 protein-induced peritoneal macrophage activation. TLR2 may utilize both TLR1 and TLR6 coreceptors for HCV core- and NS3-mediated activation of macrophages and innate immunity in humans. These results imply that multiple pattern recognition receptors could participate in cellular activation by HCV proteins contributing to inflammatory disease. Two critical factors in chronic HCV infection are inflammatory disease and immune evasion. We have demonstrated that TLR2 and its co-receptors play a role in inflammatory-mediated induction via HCV NS3 and core administration. It has recently been shown that HCV targets the TLR3 pathway to aid in immune evasion. TLR3 is only one of four viral recognition receptors located within the endosome and it is plausible that HCV may target others. We hypothesized that HCV infection may interfere with the expression and function of TLR7, a sensor of single stranded RNA. Investigating any effect on TLR7 by HCV may reveal a new mechanism for HCV immune evasion. Low levels of both TLR7 mRNA and protein were measured in HCV replicating cells compared to control cells while reducing HCV infection with either IFNα or restrictive culture conditions restored the decreased TLR7 expression. Downstream of the TLR7 pathway, an increased baseline IRF7 nuclear translocation was observed in HCV replicating cells compared to controls. Stimulation with a TLR7 ligand, R837, resulted in significant IRF7 nuclear translocation in control cells. In contrast, HCV replicating cells showed impaired IRF7 activation. Use of RNA polymerase inhibitors on hepatoma cells, control and HCV replicating, revealed a shorter TLR7 half life in HCV replicating cells compared to control cells which was not seen in TLR5 mRNA. These data suggest that reduced TLR7 expression, due to RNA instability, directly correlates with HCV replication and results in impaired TLR7-induced IRF7-mediated cell activation. In conclusion, Hepatitis C Virus manipulates specific Toll-like receptors’ expression and their signaling pathways to induce cytokine production. HCV utilizes surface receptors TLR2 and its co-receptors which once activated could contribute to inflammatory disease by production of inflammatory cytokines and possibly immune evasion. HCV down-regulates TLR7, a viral recognition receptor, by decreasing mRNA stability which could facilitate evasion of host immune surveillance.

A perfuração gástrica por endoscopia é a consequência de alguns de seus procedimentos, e atualmente, com o advento das cirurgias endoscópicas translumenais por orifícios naturais, um meio de manipulação dos órgãos abdominais. Esse é o motivo pelo qual os endoscopistas estão procurando um reparo endoscópico seguro. O objetivo foi avaliar a factibilidade e os resultados do fechamento da abertura gástrica similar àquelas realizadas nos procedimentos cirúrgicos endoscópicos translumenais por orifícios naturais utilizando-se o T-Tag associado à câmara plástica protetora. Sob anestesia geral, dez porcos Landrace foram submetidos a uma perfuração gástrica calibrada em 18 mm de diâmetro. A abertura foi fechada pelo novo método apresentado, composto de fios cirúrgicos conectados em uma âncora metálica (T-Tag) posicionados pela parede gástrica através de uma agulha. Uma câmara protetora plástica foi adaptada à extremidade distal do endoscópio para proteger os órgãos abdominais adjacentes da punção da agulha fora do estômago. Seis dispositivos T-Tag foram posicionados na maioria dos casos e os fios atados com um apertador de nó metálico endoscópico formando três pontos de sutura. O teste de vazamento foi realizado com uma pinça endoscópica e distensão da câmara gástrica com ar. Os animais receberam líquidos no mesmo dia do procedimento. Uma dose de antibiótico diária por dois dias foi administrada. Nenhuma complicação foi detectada no período pós-operatório. Um mês depois, a endoscopia revelou a presença de cicatriz em todos os animais, e a maioria apresentava materiais da sutura aderidos à superfície mucosa da região. A região do antro gástrico apresentava poucas aderências identificadas na laparotomia realizada no mesmo momento. O reparo endoscópico utilizando o T-Tag e a câmara protetora plástica é factível, fácil de ser realizada e seguro. São necessários estudos adicionais para mostrar o real valor desse tipo de procedimento
The endoscopic gastric perforation is a consequence of some endoscopic procedures and now a way to manage abdominal organs. This is the reason why endoscopists are studying a safe endoscopic repair. The objective was to evaluate feasibility and results of the gastric opening closure similar to those performed in natural orifice translumenal endoscopic surgery procedures using T-Tag associated with the plastic protection chamber. Ten Landrace pigs underwent a gastric perforation of 1.8 cm in diameter under general anesthesia. The opening was repaired with stitch assembled in a T-Tag anchor placed through the gastric wall with a needle. A plastic transparent chamber, adapted to the endoscope tip protected the abdominal organs from the needle puncture outside the stomach. Six T-Tags were placed in most cases and the stitches were tied with a metallic tie-knot, forming three sutures. The leakage test was performed with a forceps and by air distention. The animals received liquids in the same operative day. One daily shot antibiotic during two days was used. No complication was detected in the postoperative course. One month later the endoscopy revealed a scar in all animals, and the majority of these with suture material. The antral anterior gastric wall was clear with few adhesions in the laparotomy performed in the same time. The endoscopic repair using T-Tag and a protector chamber is feasible, easy to perform and safe. Further studies are needed to show the real value of this kind of procedure

Introdução: o uso da videolaparoscopia na doença de Crohn (DC) teve seu início nos anos 90, com ressalvas à possível dificuldade técnica que a DC complexa ou recorrente poderia impor à sua realização. Diversos estudos ao longo das décadas de 90 e 2000 mostraram ser a mesma factível, quando comparada à laparoscopia para DC primária, além de demonstrarem maior benefício da laparoscopia comparada à cirurgia aberta/convencional nos casos de DC recorrente. Entretanto, não houve estudos sobre resultados cirúrgicos após repetidas ressecções laparoscópicas. Objetivo: avaliar resultados pós-operatórios em curto prazo no tratamento da DC, comparando pacientes submetidos a uma segunda ressecção intestinal laparoscópica e pacientes sem cirurgia prévia. Além disso, comparar os mesmos resultados pós-operatórios entre pacientes submetidos a uma segunda ressecção intestinal laparoscópica e pacientes sendo submetidos a laparoscopia para DC e história prévia de ressecção intestinal prévia por laparotomia. Materiais e métodos: foi realizado análise retrospectiva a partir de base de dados mantida prospectivamente de pacientes submetidos a laparoscopia para tratamento da DC no Hospital Beaujon, França, entre 2005 e 2010. Os desfechos analisados foram: conversão para cirurgia aberta, tempo operatório, taxa de enterotomias inadvertidas no intra-operatório, morbidade, necessidade de reintervenção (cirúrgica ou radiológica) e tempo total de hospitalização. Resultados: foram analisados 18 pacientes com laparoscopia prévia (grupo A), 90 pacientes sem cirurgia prévia (grupo B) e 26 pacientes com laparotomia prévia (grupo C). Em nossa análise principal, comparando os grupos A e B, vemos grupos semelhantes em relação a dados demográficos, exceto maior número de casos complexos no grupo A (83,3 vs 46,7%; p=0,005) e tipo de operação realizada (p < 0,001). Quanto aos resultados, apenas o tempo operatório foi significativamente mais longo no grupo A (180 minutos vs. 150 minutos; p=0,013). A taxa de conversão, enterotomia inadvertida, morbidade, necessidade de reintervenção e tempo de hospitalização foram similares entre os grupos. Em nossa segunda análise, entre os grupos A e C, não houve diferença significativa quanto aos mesmos resultados analisados. Conclusão: apesar de um maior tempo operatório, uma segunda ressecção laparoscópica mantém os mesmos benefícios vistos em uma ressecção intestinal laparoscópica primária. Os mesmos benefícios são vistos quando os resultados são comparados com pacientes submetidos previamente a uma ressecção intestinal por laparotomia, em especial quando nas mãos de equipe experiente
Introduction: the use of laparoscopy in Crohn\'s disease (CD) had its beginning in the 90s, despite the possible challenge of technical difficulty that the complex or recurrent CD could impose to its realization. Numerous studies over the decades of 90 and 2000 showed laparoscopy in recurrent CD to be feasible compared to laparoscopy for primary CD, and have also shown the benefits of laparoscopic compared to open conventional surgery in patients with recurrent CD. However, there were no studies on surgical outcomes after repeated laparoscopic resections. Objective: 1. to evaluate postoperative short-term results regarding surgical treatment of CD, comparing patients who underwent a second laparoscopic bowel resection and patients without prior surgery. 2. to compare the same postoperative results among patients who underwent a second laparoscopic bowel resection patients and patients undergoing laparoscopic resection with history of prior intestinal resection by laparotomy. Materials and methods: a retrospective analysis from prospectively maintained database of patients undergoing laparoscopy for treatment of CD in Hospital Beaujon, France, between 2005 and 2010, was performed. The outcomes analyzed were: conversion to open surgery, operative time, intraoperative inadvertent enterotomy, morbidity, need for re-intervention (surgical or radiological) and length of hospitalization. Results: 18 patients with previous laparoscopy (group A), 90 patients without previous surgery (group B) and 26 patients with previous laparotomy (group C) were included. In our main analysis, comparing the groups A and B, groups were similar in respect to demographic data, except number of complex cases in group A (83.3 vs 46.7%; p = 0.005) and type of surgery performed (p < 0.001). As for the results, operative time was significantly longer in group A (180 minutes vs. 150 minutes; p = 0.013). Conversion rate, inadvertent enterotomy, morbidity, need for re-intervention and hospital stay were similar between groups. In our second analysis, between groups A and C, there was no significant difference between groups regarding the same variables. Conclusion. In spite of a longer operative time, a second laparoscopic resection guarantees the same benefits seen in a primary laparoscopic bowel resection. The same benefits are kept compared to patients who underwent prior bowel resection by laparotomy, especially when in the hands of experienced staff

Objetivo: Avaliar o prognóstico clínico do transplante multivisceral (TMV) na vigência de trombose difusa do sistema porto-mesentérico. Introdução. O transplante hepático (TH) na vigência de cirrose e trombose difusa do sistema porto-mesentérico é controverso e muitas vezes contraindicado em muitos centros de transplante hepático. O transplante hepático utilizando técnicas alternativas como a hemitransposição portocava falha na eliminação de complicações provenientes da hipertensão portal. O TMV substitui o fígado e todo o sistema venoso porto-mesentérico. Métodos: Uma base de dados de pacientes submetidos a transplante intestinal foi mantida com análise prospectiva de resultados. O diagnóstico de trombose difusa do sistema porto-mesentérico foi estabelecido através de tomografia abdominal em fases arterial e venosa, ou por ressonância magnética com reconstrução venosa. Resultados: Vinte e cinco pacientes com trombose de porta, estádio IV, foram submetidos ao TMV. Onze pacientes receberam transplante renal concomitante. Rejeição aguda confirmada por biópsia foi notada em cinco pacientes, que foram tratados com sucesso. Com um seguimento médio de 2,8 anos, a sobrevida de enxertos e pacientes foi de 80%, 72% e 72%, respectivamente. Até a presente data, todos os sobreviventes estão com boa função de enxerto e sem nenhum sintoma ou evidência de hipertensão portal. Conclusão: O TMV deve ser considerado como opção para o tratamento de pacientes com trombose portomesentérica difusa. O transplante multivisceral é o único procedimento que reverte completamente a hipertensão portal e a doença de base com uma sobrevida superior ao TH com reconstruções vasculares alternativas
Objective: To evaluate the clinical outcomes of multivisceral transplantation (MVT) in the setting of diffuse thrombosis of the portomesenteric venous system. Background: Liver transplantation (LT) in the face of cirrhosis and diffuse portomesenteric thrombosis (DPMT) is controversial and contraindicated in many transplant centers. LT using alternative techniques such as portocaval hemitransposition fails to eliminate complications of portal hypertension. MVT replaces the liver and the thrombosed portomesenteric system. Methods: A database of intestinal transplant patients was maintained with prospective analysis of outcomes. The diagnosis of diffuse PMT was established with dual-phase abdominal computed tomography or magnetic resonance imaging with venous reconstruction. Results: Twentyfive patients with grade IV DPMT received 25 MVT. Eleven patients underwent simultaneous cadaveric kidney transplantation. Biopsy proven acute cellular rejection was noted in 5 recipients, which was treated successfully. With a median follow-up of 2.8 years, patient and graft survival were 80%, 72%, and 72% at 1, 3, and 5 years, respectively. To date, all survivors have good graft function without any signs of residual/recurrent features of portal hypertension. Conclusions: MVT can be considered as an option for the treatment of patients with diffuse DPMT. MVT is the only procedure that completely reverses portal hypertension and addresses the primary disease, while achieving superior survival results in comparison to the alternative vascular reconstructions

Background: Treatment decisions for elderly patients with gallbladder pathology are complex. Little is known about what factors go into treatment decisions in this population. We used Medicare data to examine gender-based differences in the use of cholecystectomy vs. cholecystostomy tube placement in elderly patients with acute cholecystitis. Methods: We queried a 5% random sample of Medicare data (2009-2011) for patients >65 admitted for acute cholecystitis (by ICD-9 code) who subsequently underwent a cholecystectomy and/or cholecystostomy tube placement. Demographic information (age, race), clinical characteristics (Elixhauser index, presence of biliary pathology), and hospital outcomes (case fatality rate, length of stay, need for ICU care) were compared by gender. A multivariable model was used to examine predictors of cholecystectomy vs. cholecystostomy tube placement. Results: Of 4063 patients admitted with cholecystitis undergoing the procedures of interest just over half (58%) were women. The majority of patients (93%) underwent cholecystectomy. Compared to women, men were younger (average age 76 vs. 78, p value < 0.01) and had few comorbidities (average Elixhauser 1.2 vs. 1.4 p value < 0.01). Case fatality rate was similar between men (2.5%) and women (2.4% p value 0.48). A higher percentage of men spent time in the ICU (36%) compared to women (31% p value < 0.01). On multivariable analysis men were 30% less likely to undergo cholecystectomy (OR 0.69, 95% CI 0.53-0.91). Conclusion: Elderly men are less likely than elderly women to undergo cholecystectomy for acute cholecystitis despite being younger with less co morbidity and are more likely to spend time in the ICU. More research is needed to determine whether a difference in treatment is contributing to the higher rate of ICU utilization in elderly men with acute cholecystitis.

Introdução: obstrução gastroduodenal maligna é uma condição frequente em neoplasias gástricas e pancreáticas em estágio avançado. O tratamento paliativo visa a melhora dos sintomas e da qualidade de vida, sendo realizado pelas técnicas cirúrgicas ou endoscópicas. Embora a terapêutica cirúrgica seja consagrada, as complicações relacionadas ao procedimento e as condições clínicas desfavoráveis dos pacientes devem ser consideradas. Apesar dos avanços do tratamento endoscópico e da possibilidade de oferecer um tratamento menos invasivo, deve-se considerar as complicações e a taxa de reintervenção desta modalidade terapêutica. Novas tecnologias foram desenvolvidas para minimizar as complicações relacionadas ao uso de próteses e demandam uma análise pormenorizada. O objetivo desta revisão sistemática é comparar o tratamento endoscópico com próteses cobertas e não cobertas e o cirúrgico com gastrojejunoanastomose para obstrução gastroduodenal. Métodos: ensaios clínicos randomizados foram identificados nas bases de dados do MEDLINE, Embase, Cochrane, LILACS, SCOPUS e CINAHL. A comparação entre as próteses metálicas cobertas e não cobertas incluiu o sucesso técnico, sucesso clínico, complicações, obstrução, migração, sangramento, perfuração, fratura das próteses e reintervenção. Os desfechos usados na comparação da terapêutica cirúrgica com gastrojejunoanastomose e endoscópica com próteses foram o sucesso técnico, complicações e reintervenção. A avaliação da patência não pode ser incluída devido à falta de uniformidade dos dados extraídos. Resultados: oito artigos foram selecionados, três comparando gastrojejunostomia e próteses e cinco comparando próteses cobertas e não cobertas. A metanálise dos estudos sobre gastroenteroanastomose e próteses não demonstrou diferença significativa no sucesso técnico e número absoluto de complicações. O tratamento com próteses apresentou uma maior taxa de reintervenção que a terapêutica cirúrgica (DR = 0,26, IC 95% = 0,05 a 0,47, NNH = 4). A metanálise que comparou próteses metálicas cobertas e não cobertas não demonstrou diferença estatística significativa considerando o sucesso técnico, sucesso clínico, complicações, fratura das próteses, perfuração, sangramento e necessidade de reintervenção. Uma maior taxa de migração foi atribuída à terapêutica com próteses cobertas (DR = 0,09, IC 95% = 0,04 a 0,14, NNH = 11). Entretanto, o tratamento com próteses cobertas apresenta menor taxa de obstrução em relação às não cobertas (DR = -0,21, IC 95% = -0,27 a -0,15, NNT = 5). Uma análise de subgrupo de estudos com próteses metálicas que incluíram apenas pacientes com câncer gástrico demonstrou resultado semelhante à metanálise com todos os artigos. Conclusões: o tratamento endoscópico paliativo da obstrução gastroduodenal maligna com próteses cobertas apresenta maior taxa de migração e menor número de obstruções quando comparado com o uso de próteses não cobertas. A terapêutica cirúrgica com gastrojejunoanastomose associa-se a uma menor taxa de reintervenção em relação ao uso de próteses
Introduction: malignant gastric outlet obstruction is a frequent condition in advanced gastric and pancreatic neoplasms. Palliative treatment can be performed by endoscopic or surgical techniques. Palliation aims to relief symptoms and increase quality of life. Although surgical therapy is the established treatment, the complication rate of the procedure and the unfavorable clinical conditions must be considered. Despite the advances in the endoscopic treatment and the possibility to offer a minimally invasive therapy, complication rate and need of reintervention must be reminded. New technologies have been developed to minimize the complications related to the use of stents and require a detailed analysis. This systematic review aims to compare surgery and covered and uncovered stent treatments for gastric outlet obstruction. Methods: randomized clinical trials were identified in MEDLINE, Embase, Cochrane, LILACs, BVS, SCOPUS and CINAHL databases. Comparison of covered and uncovered stents included: technical success, clinical success, complications, obstruction, migration, bleeding, perforation, stent fracture and reintervention. The outcomes used to compare Gastrojejunostomy and stents were technical success, complications and reintervention. Patency rate could not be included because of lack of uniformity of the extracted data. Results: eight studies were selected, three comparing gastrojejunostomy and stents and five comparing covered and uncovered stents. The meta-analysis of surgical and endoscopic stent treatment showed no difference in the technical success and overall number of complications. Stents had higher reintervention rates than surgery (RD: 0.26, 95% CI [0.05, 0.47], NNH: 4). There is no significant difference in technical success, clinical success, complications, stent fractures, perforation, bleeding and the need for reintervention in the analyses of covered and uncovered stents. There is a higher migration rate in the covered stent therapy compared to uncovered self-expanding metallic stents in the palliation of malignant gastric outlet obstruction (RD: 0.09, 95% CI [0.04, 0.14], NNH: 11). Nevertheless, covered stents had lower obstruction rates (RD: -0.21, 95% CI [-0.27, - 0.15], NNT: 5). A subgroup analysis with studies that included only patients with gastric cancer showed similar results when compared with the analysis with all trials. Conclusions: in the palliation of malignant gastric outlet obstruction, covered stents had higher migration and lower obstruction rates when compared with uncovered stents. Gastrojejunostomy is associated with lower reintervention rates than stents

O volvo colônico de sigmóide, juntamente com o fecaloma e a perfuração de cólon, representam as principais complicações do megacólon chagásico. O volvo do cólon sigmóide é definido como a torção axial da alça sobre seu meso, num ângulo maior que 180 graus, e leva a um quadro clínico de obstrução intestinal clássico que pode ainda ser complicado pela associação de fecaloma, perfuração e necrose. Estudou-se retrospectivamente os prontuários de 130 doentes, 55 mulheres e 75 homens com idade média de 58,1 anos com diagnóstico de volvo de cólon sigmóide, os quais foram tratados cirurgicamente na urgência. Os doentes foram selecionados em dois grupos, sendo o grupo I submetido a tratamento derivativo na urgência, compreendendo subgrupos: grupo IA: Destorção e colostomia em alça; grupo IB: Procedimento de Hartmann; grupo IC: Colectomia total. No grupo II foram avaliados os doentes submetidos a tratamento definitivo na urgência - operação de Duhamel-Haddad. Foram analisados dados referentes aos diagnósticos clínico, radiológico, etiológico, às complicações pós-operatórias e à mortalidade. A taxa de morbidade geral foi de 17,7%; a mortalidade na urgência foi de 6,2%. A morbi-mortalidade do tratamento cirúrgico de urgência foi: grupo IA = 7,8%; grupo IB = 20,8%; grupo IC = 22,2% e grupo II = 27,3%. A permanência hospitalar média foi de 5,6 dias, sendo a maior no grupo II, com média de 10 dias. Quando se analisa os doentes que foram submetidos eletivamente à operação de Duhamel-Haddad para reconstrução do trânsito intestinal, obtém-se uma taxa de morbi-mortalidade de 38,8% e permanência hospitalar de 9,9 dias (14,1 dias no total) no grupo submetido à destorção com colostomia em alça (grupo IA). No grupo que sofreu cirurgia de Hartmann (grupo IB) de 46,2% e a permanência hospitalar foi de 11,1 dias (17,2 dias no total). Concluiu-se que: 1) o ideal é associar o tratamento definitivo do megacólon ao do volvo colônico na urgência, quando as condições clínicas o permitirem, por implicar em menor tempo de internação e menor morbi-mortalidade total; 2) a operação de Duhamel-Haddad realizada ulteriormente associou-se a maior número de complicações do que quando feita na urgência
Acute sigmoid volvulus, fecal impaction and colonic perforation are the major complications of chagasic megacolon. Sigmoid volvulus is defined as the torsion of the sigmoid colon over its mesenteric axis more than 180 degrees. Clinically, patients present signs and symptoms of bowel obstruction that may be worsen if occurs isquemia, necrosis and perforation. Files of 130 cases admitted at emergency unit and diagnosed as having sigmoid volvulus was reviewed: 55 women and 75 men with age ranging from 26 to 89 years. Patients were divided into two groups: Group I: submitted to derivative colostomy; Group IA - volvulus detorsion and loop colostomy; Group IB - Hartmann\'s procedure and Group IC - total colectomy. Group II: submitted to Duhamel-Haddad procedure, i.e., simultaneous treatment of volvulus and its cause, the megacolon. Data concerning to clinical and radiological diagnosis, etiologic factors, surgical treatment and outcomes were analyzed. Overall morbidity rate were 17.7% and mortality were 6.2%. Morbi-mortality of the surgical treatment in urgency was: Group IA= 7.8%; Group IB = 20.8%; Group IC = 22.2% and Group II = 27.3%. Median hospital stay was 5.6 and 10 days for groups I and II, respectively. Elective intestinal transit reconstruction in groups IA and IB showed: morbidity of 38% and 46.2%, median hospital stay of 9.9 and 11.1 days, respectively. Conclusions: Duhamel-Haddad procedure as a surgical option for the treatment of sigmoid volvulus is associated with short hospital stay and less outcomes; Duhamel- Haddad procedure, as an emergency operation, was associated with fewer complications than programmed ones

INTRODUÇÃO: A secreção do hormônio de crescimento (GH) está diminuída em obesos. Existem controvérsias se esta diminuição é conseqüência ou um dos fatores causais da obesidade. Perda de peso leva a alguma recuperação da secreção de GH. Não há estudos publicados sobre o efeito da derivação gástrica (gastrojejunal) com anastomose em Y-de-Roux (BPG) sobre o perfil de secreção de 24 h de GH. Por outro lado, a ghrelina é um peptídeo secretagogo de GH produzido no estômago, orexigênico, lipogênico e adipogênico, cujos níveis oscilam ao longo do dia e estão diminuídos na obesidade. As variações circadianas de ghrelina têm papel no controle da homeostase energética e secreção de GH. O nível de ghrelina eleva-se com perda de peso induzida por dieta, mas os dados são controversos sobre mudanças desses níveis após cirurgias bariátricas. Este estudo tem por objetivo caracterizar os perfis de secreção de GH e ghrelina em mulheres com obesidade grau III antes e após BPG e suas correlações com variáveis metabólicas. MÉTODOS: Coletas de sangue a cada 20 minutos por 24 horas foram realizadas em obesas mórbidas não diabéticas na pré-menopausa antes e seis meses após BPG. O procedimento foi realizado em balanço calórico neutro por quatro dias. Foram dosados glicose e insulina; GH em todas as amostras e ghrelina às 08:00h, 10:00h, 12:00h, 19:00h e 02:00h. A taxa metabólica de repouso (TMR) foi avaliada por calorimetria indireta e as massas adiposa (MA) e magra (MM) foram medidas por DEXA. RESULTADOS: Houve uma redução de 27% do peso corporal e IMC (de 55,9 ± 6,2 kg/m2 para 40,7 ± 5,8 kg/m2, p<0,001) com elevação de vários parâmetros de secreção de GH (GH basal, GH médio, p<0,05; área, amplitude e número de picos, p<0,001); redução de glicemia (p = 0,03), insulinemia de jejum (p = 0,005) e HOMA (p = 0,004). Não houve diferença nos níveis de ghrelina basal, pós-prandial e médio. O GH médio apresentou correlação negativa com as mudanças no peso (p = 0,003; r = -0,631), IMC (p <0,001; r = -0,731), MA (p = 0,003; r = -0,635), MM (p = 0,02; r = -0,507), circunferência abdominal (p = 0,01; r = -0,555), TMR (p = 0,01; p = -0,539), insulina de jejum (p = 0,014, r = -0,538) e HOMA (p = 0,01; r = -0,560), mas não com a glicemia de jejum (p = 0,13; r = -0,354) e a ghrelina (p = 0,6; r = 0,118). O melhor determinante da secreção de GH foi o IMC sendo responsável por 54% da variação do GH médio (r2 = 0,54). CONCLUSÕES: Há uma recuperação parcial da secreção de GH, reduzida no pré-operatório em obesas mórbidas, após perda de peso induzida seis meses após a cirurgia, indicando que a secreção reduzida não é um fator primário ou causal da obesidade, mas sim uma conseqüência da obesidade e essa recuperação é independente do perfil de secreção de ghrelina
INTRODUCTION: Growth hormone (GH) concentration is decreased in obesity. It is not clear if reduced GH secretion is consequence or cause of the obese state. GH secretion is partially restored by weight loss. There are no published studies about the effect of Roux-en-Y gastric bypass (RYGBP) on GH secretory profile. Ghrelin is a GH releasing peptide produced by stomach, with orexigenic, lipogenic and adipogenic actions. Ghrelin levels oscillate throughout the day and are low in obesity. Circadian changes in ghrelin levels have a role both in energy homeostasis control and GH secretion. Ghrelin levels rise after diet-induced weight loss, but results are controverse in relation to changes in ghrelin levels after bariatric surgeries. In this study, we analyzed GH and ghrelin concentrations in morbidly obese women before and after RYGBP and its relationships with metabolic parameters. METHODS: Blood was sampled at 20-minute intervals during 24 hours in non diabetic pre-menopausal morbid obese women before and six months after RYGBP. The study was done after four days in neutral caloric balance. Fasting glucose and insulin were determined in basal samples. GH concentrations were measured in all samples and ghrelin in serum collected at 08:00h, 10:00h, 12:00h, 19:00h e 02:00h. Resting metabolic rate (RMR) was evaluated by indirect calorimetry and fat mass (FM) and free-fat mass (FFM) were measured by DEXA. RESULTS: A 27% drop in body weight and BMI (55.9 ± 6.2 kg/m2 to 40.7 ± 5.8 kg/m2, p<0.001), augmentation of spontaneous GH secretory episodes (basal and mean levels, p <0.05; area, amplitude and peak frequency, p <0.001); and reduction of fasting glucose (p = 0.03), insulinemia (p = 0.005) and HOMA (p = 0.004) were observed. Neither basal, post-prandial or mean ghrelin were changed. A negative correlation was found between mean GH levels and weight changes (p = 0.003, r = -0.631), BMI (p <0.001, r = -0.731), FM (p = 0.003, r = -0.635), FFM (p = 0.02, r = -0.507), waist (p = 0.01, r = -0.555), RMR (p = 0.01, p = -0.539), fasting insulin (p = 0.014, r = -0.538), as well as HOMA (p = 0.01, r = -0.560), but not between mean GH levels and glucose (p = 0.13, r = -0.354) or ghrelin (p = 0.6, r = 0.118). BMI accounted for 54% of the mean GH variation (r2 = 0.54). CONCLUSIONS: There is a partial recovery of GH secretion after weight loss induced by RYGBP, suggesting that a blunted secretion is not a primary or causal factor of obesity, but a consequence of the obese state. This recovery is independent of ghrelin secretory profile

The aim of this PhD study was to develop a locomotion system for use on a robotic device that can traverse a liquid filled colon for atraumatic inspection and biopsy tasks. The PhD was undertaken as part of a larger two-centre EU project, which aimed to bring about a change in the way colonoscopy is done by moving to “robotic hydro-colonoscopy”. Current colonoscopes have seen little change or innovation throughout their 40 years of use with patient discomfort still limiting success and adherence of the procedure. In this thesis the initial development and testing of an amphibious locomotion concept for use in a liquid filled colon during a procedure known as hydrocolonoscopy is described. The locomotion system is comprised of four Archimedes’ screws arranged in two counter rotating pairs. These aim to provide propulsion through a liquid filled colon as well as provide locomotive traction against colonic tissue in partially fluid filled or collapsed sections of the colon, such as the splenic flexure. Experimental studies were carried out on a single screw system in fluid and dual counter-rotating screws in contact conditions. These show the system’s ability to generate thrust in the two discrete modes of locomotion of the amphibious system. A 2:1 scale prototype of the proposed device was produced from multiple materials using additive layer manufacturing processes and commercially available components. The prototype features compliant screw threads to provide atraumatic locomotion; through material selection the components will yield before damage to tissue occurs. The scale prototype device was tested in an ex-vivo porcine colon which demonstrated that this concept has the potential to be used for an intra-luminal robotic device. The key contributions of this research are: variable geometry locomotion system; amphibious locomotion using Archimedes’ screws; experimental assessment of the locomotion in fluid, contact and amphibious states; and analysis of the contact dynamics against tissue.

Several surgically corrective procedures are considered to treat Adult Acquired Flatfoot Deformity (AAFD) patients, relieve pain, and restore function. Procedure selection is based on best practices and surgeon preference. Recent research created patient specific models of Adult Acquired Flatfoot Deformity (AAFD) to explore their predictive capabilities and examine effectiveness of the surgical procedure used to treat the deformity. The models’ behavior was governed solely by patient bodyweight, soft tissue constraints, and joint contact without the assumption of idealized joints. The current work expanded those models to determine if an alternate procedure would be more effective for the individual. These procedures included one hindfoot procedure, the Medializing Calcaneal Osteotomy (MCO), and one of three lateral column procedures: Evans osteotomy, Calcaneocuboid Distraction Arthrodesis (CCDA), Z osteotomy and the combination procedures MCO & Evans osteotomy, MCO & CCDA, and MCO & Z osteotomy all used in combination with a tendon transfer. The combination MCO & Evans and MCO & Z procedures were shown to provide the greatest amount of correction for both forefoot abduction and hindfoot valgus. However, these two procedures significantly increased the joint contact force, specifically at the calcaneocuboid joint, and ground reaction force along the lateral column. With exception to the lateral bands of the plantar fascia and middle spring ligament, the strain present in the plantar fascia, spring, and deltoid ligaments decreased after all procedures. The use of patient specific computational models provided the ability to investigate effects of alternate surgical corrections on restoring biomechanical function in flatfoot patients.

Stroke is the third most common cause of death and a leading cause of disability in the United States. The existing treatments of acute ischemic stroke (AIS) involve pharmaceutical thrombolytic therapy and/or mechanical thrombectomy. The Food and Drug Administration (FDA)-approved recombinant tissue plasminogen activator (tPA) administration for treatment of stroke is efficacious, but has a short treatment time window and is associated with a risk of symptomatic hemorrhage. Other than tPA, the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) retriever system and the Penumbra Aspiration system are both approved by the FDA for retrieval of thromboemboli in AIS patients. However, the previous clinical studies have shown that the recanalization rate of the MERCI system and the clinical outcome of the Penumbra system are not optimal. To identify the variables which could affect the performance of the thrombectomy devices, much effort has been devoted to evaluate thrombectomy devices in model systems, both in vivo and in vitro, of vascular occlusion. The goal of this study is to establish a physiologically realistic, in vitro model system for the preclinical assessment of mechanical thrombectomy devices. In this study, the model system of cerebrovascular occlusion was mainly composed of a human vascular replica, an embolus analogue (EA), and a simulated physiologic mock circulation system. The human vascular replica represents the geometry of the internal carotid artery (ICA)/middle cerebral artery (MCA) that is derived from image data in a population of patients. The features of the vasculature were characterized in terms of average curvature (AC), diameter, and length, and were used to determine the representative model. A batch manufacturing was developed to prepare the silicone replica. The EA is a much neglected component of model systems currently. To address this limitation, extensive mechanical characterization of commonly used EAs was performed. Importantly, the properties of the EAs were compared to specimens extracted from patients. In the preliminary tests of our model system, we selected a bovine EA with stiffness similar to the thrombi retrieved from the atherosclerotic plaques. This EA was used to create an occlusion in the aforesaid replica. The thrombectomy devices tested included the MERCI L5 Retriever, Penumbra system 054, Enterprise stent, and an ultrasound waveguide device. The primary efficacy endpoint was the amount of blood flow restored, and the primary safety endpoint was an analysis of clot fragments generated and their size distribution. A physiologically realistic model system of cerebrovascular occlusion was successfully built and applied for preclinical evaluation of thrombectomy devices. The recanalization rate of the thrombectomy device was related to the ability of the device to capture the EA during the removal of the device and the geometry of the cerebrovasculature. The risk of the embolic shower was influenced by the mechanical properties of the EA and the design of the thrombectomy device.

NOD mice model human type 1 diabetes and have been used to investigate tolerance induction protocols for islet transplantation in a setting of autoimmunity. Costimulation blockade-based tolerance protocols that induce prolonged skin and permanent islet allograft survival in non-autoimmune mice have failed in NOD mice. To investigate the underlying mechanisms, we generated NOD hematopoietic chimeras. We were able to show that dendritic cell maturation defects seen in NOD mice are partially corrected in mixed hematopoietic chimeras. Furthermore, skin allograft survival was dependent upon the phenotype of the bone marrow donor, demonstrating that in the NOD the resistance to tolerance induction resides in the hematopoietic compartment. In addition, we studied congenic NOD mice bearing insulin dependent diabetes (Idd) loci that reduce diabetes incidence. The incidence of diabetes is reduced in NOD.B6 Idd3 mice, and virtually absent in NOD.B6 Idd3Idd5 mice. Islet allograft survival in NOD.B6 Idd3 mice is prolonged as compared to NOD mice, and in NOD.B6 Idd3Idd5 mice islet allograft survival is similar to that achieved in C57BL/6 mice. Alloreactive CD8 T cell depletion in NOD mice treated with costimulation blockade is impaired, but is partially restored in NOD.B6 Idd3 mice, and completely restored in NOD.B6 Idd3Idd5 mice. Idd3 results from variations in Il2 gene transcription. We hypothesized insufficient levels of IL-2 in NOD mice contributes to impaired deletion of alloreactive CD8 T cells and shortened islet allograft survival. We observed using synchimeric mice that co-administration of exogenous IL-2 to NOD mice treated with costimulation blockade led to deletion of alloreactive CD8 T cells comparable to that in C57BL/6 mice and prolonged islet allograft survival. However, some Idd loci impaired the induction of transplantation tolerance. These data suggest that Idd loci can facilitate or impair induction of transplantation tolerance by costimulation blockade, and that Idd3 (IL-2) is critical component in this process.

Uvod: Primarna fokalna hiperhidroza (PFH) je poremećaj nepoznate etiologije koji se karakteriše prekomernim znojenjem na predilekcionim mestima. Podjednako se javlja kod osoba muškog i ženskog pola tokom dvadesetih i početkom tridesetih godina života, pri čemu se smatra da je učestalos PFH oko 2,8% u ukupnoj populaciji. Nastaje kao posledica hiperaktivnosti simaptičkog nervnog sistema ka znojnim žlezdama. Karakteristično je za PFH da se ne javlja noću, što sugeriše da emocionalni stimulus igra bitnu ulogu u nastanku ovog poremećaja. Bilateralna torakoskopska simpatektomija (BTS) je minimalno invazivna hirurška procedura koja se danas primenjuje u trajnom lečenju PFH, sa niskom stopom komplikacija i omogućava lečenje kao jednodnevne hirurške procedure. Ciljevi ovog istraživanja su bili: a) da se ispita ukupna efikasnost BTS na trajno smanjenje PFH predilekcionih delova tela - dlanova, pazušnih jama, lica i stopala; b) da se ispita efiksanost BTS kod osoba sa PFH u odnosu na različite nivoe transekcije simpatičkog lanca; c) da se ispita uticaj BTS na plućnu i srčanu funkciju kod operisanih osoba sa PFH; d) da se ispita pojava, trajanje i intenzitet kompenzatornog znojenja nakon BTS kod operisanih osoba sa PFH; e) da se ispita pojava, trajanje, lokalizacija i tretman postoperativnog bola nakon BTS kod osoba sa PFH; f) da se utvrde postoperativne komplikacije BTS kod osoba sa PFH; i g) da se ispita uticaj BTS na kvalitet života kod operisanih osoba sa PFH. Radna hipoteza istraživanja je bila da hirurška procedura - minimlano invazivna BTS ima značajan efekat na prekomerno znojenje na predilekcionim mestima kod osoba sa PFH, da je praćena sa minimalnim morbiditetom, bez kliničkog uticaja na plućnu i srčanu funkciju i da značajno poboljšava kvalitet života operisanih osoba. Materijal i metod: Urađena je prospektivna klinička studija koja je uključila 435 osoba sa PFH, koji su operisani bilateralnom torakoskopskom simpatektomijom, na Klinici za grudnu hirurgiju, Instituta za plućne bolesti Vojvodine u Sremskoj Kamenici između 2010 i 2014 godine. Kriterijumi za uključivanje u studiju bili su: a) da su osobe sa utvrđenom i procenjenom PFH pristale da učestvuju u istraživanju ispunjavajući preoperativno i postoperativno upitnike o efektima BTS i kvalitetu života nakon operacije; b) da nisu imali prethodne grudno hirurške intervencije, frakture rebara, masivne pneumonije ili empijem pleure; c) da nisu imali teški poremećaj plućne ili srčane funkcije; d) da ne boluju od sekundarne hiperhidroze. Primarna fokalna hiperhidroza je bila ustanovljena i procenjena anamnestičkim podacima, kliničkom slikom i pregledom koji je bio fokusiran na kvalitativno ispitivanje. Bilateralna torakoskopska simpatektomija izvođena je u opštoj anesteziji, a transekcija simpatičkog lanca je rađena pomoću ultrazvučno aktiviranog skalpela. Osobe sa izvedenom BTS zbog PFH bile su klasifikovane u tri grupe, u zavisnosti od nivoa transekcije simpatičkog lanca: a) transekcija na nivou drugog do četvrtog torakalnog gangliona (T2-T4); b) transekcija na nivou trećeg do četvrtog torakalnog gangliona (T3-T4); i c) transekcija na nivou drugog do trećeg torakalnog gangliona (T2-T3). Za procenu kompenzatornog znojenja i kvaliteta života korišćene je: Hyperhidrosis Disease Severity Scale (HDSS) za intenzitet kompenzatornog znojenja i kvaliteta života nakon BTS. Rezultati: Od 435 osoba sa PFH kod kojih je urađena BTS, bilo je 142 (32,64%) osobe muškog pola i 293 (67,36%) osoba ženskog pola, prosečne starosti od 29,68±7,6 godina. Pozitivan nasledni faktor navelo je 167 osoba (38,62%). Najčešća lokalizacija prekomernog znojenja kod osoba u ovom istraživanju je bila kombinacija dlanova, pazušnih jama i tabana, koju je imalo 167 osoba (38,39%). Pre operacije, preko 60% ispitivanih osoba je navelo da im je kvalitet života loš ili izuzetno loš. Kod svih operisanih osoba u ovom istraživanju, operacija je izvedena uspešno obostrano. Nije bilo smrtnih ishoda. Od intraoperativnih komplikacija zabeležena je jedna konverzija (0,23%) u minitorakotomiju zbog krvavljenja iz interkostalne vene. Neposredni postoperativni uspeh BTS kod operisanih osoba zbog PFH, a na osnovu prve kontrole posle nedelju dana bio je zabeležen kod svih (99,54%), osim kod dve osobe (0,46%) koje su imale postoperativne komplikacije: pareza n. ulnarisa i Hornerov sindrom kod jedne osobe i Horner sindrom kod druge osobe. Postoperativni morbiditet nakon BTS bio je zabeležen kod 32 osobe (7,35%). Izrazito poboljšanje, odnosno značajno smanjenje znojenja kod osoba sa PFH zabeleženo je kod 428 operisanih (98,39%). Osobe sa transekcijom simpatičkog lanca na nivou gangliona T3-T4 imali su najbolji rezultat sa poboljšanjem kvaliteta života u 85,03% operisanih. Kompenzatorno znojenje se nakon BTS javilo kod 316 (72,64%) operisanih osoba, a samo 2,53% je navelo da je postoperativno kompenzatorno znojenje izuzetno jakog intenziteta. Postoperativni bol bio je prisutan kod 79,77% operisanih osoba, sa prosečnim trajanjem do dve nedelje. Analgetike je postoperativno koristilo 24,21% anketiranih osoba. Od 287 operisanih osoba u ovom istraživanju, koji su pre operacije naveli da su imali i prekomerno znojenje tabana, nakon 6 meseci 185 osoba (64,46%) je navelo da se prekomerno znojenje tabana smanjilo. Iako postoji statistička značajnost u promeni vitalnog kapaciteta u smislu njegovog povećanja šest meseci nakon BTS (sa 4,49±1,15 L na 4,54±1,11 L), ta promena nije bila klinički relevantna. Promene u krvnom pritisku i srčanom pulsu, iako zabeležene, takođe nisu imale klinički značaj. Kvalitet života, pre BTS ocenjen kao loš (i izuzetno loš) bio je prisutan kod 265 osoba (60, 92%), a 6 meseci posle operacije ocenjen je kao odličan i dobar kod 428 osoba (98,39%). Zaključak: BTS kao minimalno invazivna hirurška procedura kod osoba sa PFH ima minimalni morbiditet, a visoku uspešnost u smanjenju prekomernog znojenja na predilekcionim mestima, sa poboljšanjem kvaliteta života kod 98,39% operisanih, sa minimalnim promenama plućne i srčane funkcije koje nisu klinički relevantne.
Primary focal hyperhidrosis (PFH) is a disorder of an unknown etiology, characterized by excessive sweating of predilective parts of the body. It affects men and women equally, with a peak incidence in the later second and early third decades of life, with incidence of up to 2,8% of the world population. It is caused by hyperactivity of the sympathetic nervous system to the sweat glands. It has been shown that PFH does not occur during the sleeping times, which suggests that emotional stimuli play an important role in this disorder. Bilateral thoracoscopic sympathectomy (BTS) is minimal invasive surgical procedure, which has evolved into an effective and permanent treatment for severe PFH, with low rate of morbidity and it can be performed as the one day surgical procedure. The aims of this investigation were: a) to examine the overall efficiency of BTS on permanent reduction of PFH of predilective parts of the body-palms, armpits, faces and soles; b) to examine the efficiency of BTS with different levels of transection among the persons with the PFH; c) to examine the influence of BTS on cardio-pulmonary function tests in persons with PFH after the operation; d) to examine the incidence, duration and intensity of compensatory sweating after BTS among persons with PFH; e) to examine the incidence, duration, localization and treatment of postoperative pain after BTS among persons with PFH; f) to determine postoperative complications of BTS among persons with PFH; g) to examine the influence of BTS on quality of life among persons with PFH. The working hypothesis of this investigation is that surgical procedure – minimal invasive BTS has the permanent effect on excessive sweating of predilective parts of the body among persons with PFH, followed by minimal morbidity, without clinical influence on cardio-pulmonary function and significantly improves the quality of life among persons with PFH. This was a prospective clinical study which included 435 patients with PFH, who have been operated with BTS, at the Clinic for Thoracic surgery, the Institute for pulmonary diseases of Vojvodina, Sremska Kamenica, between 2010 and 2014. The including criteria for the investigation were: a) persons with confirmed and estimated PFH accepted to participate in this investigation, fulfilling pre and postoperatively questionnaire about BTS effects and quality of life after the operation; b) absence of previous thoracic surgical procedures, rib fractures, massive pneumonias or pleural empyema; c) satisfactory cardio-respiratory function; d) absence of secondary hyperhidrosis. Primary focal hyperhidrosis was confirmed and estimated by anamnesis, clinical examination focused on qualitatively examination. Bilateral thoracoscopic sympathectomy was performed with general anesthesia, using harmonic scalpel for transection of sympathetic chain. Persons with PFH who underwent the BTS were classified into three groups, depending the level of transaction of sympathetic chain: a) transection at the level from the second to the forth thoracic sympathetic ganglion (T2-T4); b) transection at the level from the third to the forth thoracic sympathetic ganglion (T3-T4); c) transection at the level from the second to the third thoracic sympathetic ganglion (T2-T3). For the assessment of postoperative pain, compensatory sweating and quality of life next scales have been used: standardized numeric pain rating scale and Hyperhidrosis Disease Severity Scale (HDSS) for intensity of compensatory sweating and quality of life. Among 435 persons with PFH who underwent the BTS in this investigation, 142 (32,64%) were male and 293 (67,36%) female persons, with mean age of 29,68±7,6. There was no mortality or serious intraoperative complications that required operative conversio from minimal invasive surgical procedure to thoracotomy. Among 435 persons with PFH who underwent the BTS in this investigation, 142 (32,64%) were male and 293 (67,36%) female persons, with mean age of 29,68±7,6. Positive genetic factor has been found in 167 persons (38,62%). The most common localisation of excessive sweating in this investigation was the combination of palms, armpits and soles in 167 persons (38,39%). Before the operation, over 60% of persons estimated their quallity of life as bad or very bad. The operation was successfully performed in all patients bilaterally. There was no mortality in this investigation. There was one intraoperative complication, bleeding from intercostal vein, requiring conversion to minithoracotomy. Immediatelly postoperative success after BTS seven days after the operation was achieved in all persons accepted in two persons (0,46%) due to the postoperative complications: nervous ulnaris paresis and Horner syndrome in one person and Horener syndome in the other person. Postoperative morbidity after the BTS was recoreded in 32 persons (7,35%). Marked improvement, as significant reduction of sweating in persons with PFH was achieved in 428 operated persons (98,39%). Transection of sympathetic chain on level T3-T4 achieved improvement of quality of life in 85,03% operated persons with PFH. Compensatory sweating after the BTS has occurred in 316 (72,64%) operated persons, but only 2,53% operated persons declared compensatory sweating as severe. Postoperative pain was presented in 79,77% operated persons, with average duration of two weeks. Analgetics used only 24,21% of operated persons. There were 287 operated persons in this investigation, who claimed to have plantar hyperhidrosis before the operation and six months after the operation 185 persons (64,46%) claimed to have a reduction of plantar sweating. Although there was a clinical significance in changes of vital capacity after the BTS (from 4,49±1,15 L to 4,54±1,11 L), ther was no clinical significance. Changes in blood pressure and heart rate, although recoreded, had no clinical significance. Quality of life, before the BTS was recorded as bad or very bad in 265 persons (60,92%), and six months after the operation as excellent or good in 428 persons (98,39%) persons. Conclusion: In patients with PFH, BTS as minimal invasive surgical procedure, has a minimal morbidity and high success in treatment of excessive sweating, with improvemnet of quality of life in 98,39% operated person, with changes in cardio-pulmonary functions that are not clinical relevant.

Parkinson’s disease (PD) is a disorder of the nervous system that causes problems with movement (motor symptoms) as well as other problems such as mood disorders, cognitive changes, sleep disorders, constipation, pain, and other non-motor symptoms. The severity of PD symptoms worsens over time as the disease progresses, and while there are treatments for the motor and some non-motor symptoms there is no known cure for PD. Thus there is a high demand for therapies to slow the progressive neurodegeneration observed in PD. Two clinical trials at the University of Kentucky College of Medicine (NCT02369003, NCT01833364) are currently underway that aim to develop a disease-modifying therapy that slows the progression of PD. These clinical trials are evaluating the safety and feasibility of an autologous peripheral nerve graft to the substantia nigra in combination with Deep Brain Stimulation (DBS) for the treatment of PD. By grafting peripheral nerve tissue to the Substantia Nigra, the researchers aim to introduce peripheral nerve tissue, which is capable of functional regeneration after injury, to the degenerating Substantia Nigra of patients with PD. The central hypothesis of these clinical trials is that the grafted tissue will slow degeneration of the target brain region through neural repair actions of Schwann cells as well as other pro-regenerative features of the peripheral nerve tissue. This dissertation details analysis of the peripheral nerve tissue used in the above clinical trials with respect to tissue composition and gene expression, both of injury-naive human peripheral nerve as well as the post-conditioning injury nerve tissue used in the grafting procedure. RNA-seq analysis of sural nerve tissue pre and post-conditioning show significant changes in gene expression corresponding with transdifferentiation of Schwann cells from a myelinating to a repair phenotype, release of growth factors, activation of macrophages and other immune cells, and an increase in anti-apoptotic and neuroprotective gene transcripts. These results reveal in vivo gene expression changes involved in the human peripheral nerve injury repair process, which has relevance beyond this clinical trial to the fields of Schwann cell biology and peripheral nerve repair. To assess the neurobiology of the graft post-implantation we developed an animal model of the grafting procedure, termed Neuro-Avatars, which feature human graft tissue implanted into athymic nude rats. Survival and infiltration of human graft cells into the host brain were shown using immunohistochemistry of Human Nuclear Antigen. Surgical methods and outcomes from the ongoing development of this animal model are reported. To connect the results of these laboratory studies to the clinical trial we compared the severity of motor symptoms before surgery to one year post-surgery in patients who received the analyzed graft tissue. Motor symptom severity was assessed using the Unified Parkinson’s Disease Rating Scale Part III. Finally, the implications and future directions of this research is discussed. In summary, this dissertation advances the translational science cycle by using clinical trial findings and samples to answer basic science questions that will in turn guide future clinical trial design.

The NOD mouse is a widely studied model of type 1 diabetes. The loss of self-tolerance leading to autoimmune diabetes in NOD mice involves at least 27 genetic loci. Curing type I diabetes in mice and humans by islet transplantation requires overcoming both allorejection and recurrent autoimmunity. This has been achieved with systemic immunosuppression, but tolerance induction would be preferable. In addition to their genetic defects in self-tolerance, NOD mice resist peripheral transplantation tolerance induced by costimulation blockade using donor-specific transfusion and anti-CDl54 antibody. Failure has been attributed to the underlying autoimmunity, assuming that autoimmunity and resistance to transplantation tolerance have a common basis. Hypothesizing that these two abnormalities might be related, we investigated whether they had a common genetic basis. Diabetes-resistant NOD and C57BL/6 stocks congenic for various reciprocally introduced Idd loci were assessed for their ability to be tolerized. Surprisingly, in NOD congenic mice that are almost completely protected from diabetes, costimulation blockade failed to prolong skin allograft survival. In reciprocal C57BL/6 congenic mice with NOD-derived Idd loci, skin allograft survival was readily prolonged by costimulation blockade. Unexpectedly, we observed that (NOD x C57BL/6)F1 mice, which have no diabetes, nonetheless resist induction of tolerance to skin allografts. Further analyses revealed that the F1 mice shared the dendritic cell maturation defects and abnormal CD4+ T cell responses of the NOD but had lost its defects in macrophage maturation and NK cell activity. Finally, using a genome wide scan approach, we have identified four suggestive markers in the mouse genome that control the survival of skin allografts following DST and anti-CD154 mAb therapy. We suggest that mechanisms controlling autoimmunity and transplantation tolerance in NOD mice are not completely overlapping and are potentially distinct, or that the genetic threshold for normalizing the transplantation tolerance defect is higher than that for preventing autoimmune diabetes. We conclude that resistance to allograft tolerance induction in the NOD mouse is not a direct consequence of overt autoimmunity and that autoimmunity and resistance to costimulation blockade-induced transplantation tolerance phenotypes in NOD mice are not under identical genetic control.

The transplantation of allogeneic cells and tissues for the treatment of human disease has been a life-saving procedure for many thousands of patients worldwide. However, to date, neither solid organ transplantation nor bone marrow transplantation have reached their full clinical potential. Significant limitations to the advancement of clinical transplantation stem from our current inability to prevent the rejection of allogeneic tissues by the immune system of the host. Similarly, in patients that receive allogeneic bone marrow transplants, we cannot permanently prevent the engrafted immune system from mounting a response against the patient. This problem, termed graft versus host disease is the most prevalent cause of morbidity and mortality in recipients of allogeneic bone marrow transplants. Clinically, we rely on lifelong immunosuppression to prolong survival of allogeneic tissues within the host. Our currently available therapeutics burden patients with side-effects that range from being unpleasant to life-threatening, while in most cases offering only a temporary solution to the problem of alloimmunity. Efforts are underway to develop protocols and therapeutics that more effectively prevent the pathology associated with alloimmunity. To minimize patient risk, extensive pre-clinical studies in laboratory animals are conducted to predict clinical responses. In the case of immunologic studies, many of these pre-clinical studies are carried out in murine models. Unfortunately, studies of murine immunity often do not predict outcomes in the clinic. One approach to overcome this limitation is the development of a small animal model of the human immune system. In this dissertation, we hypothesized that NOD-scid IL2rγnull mice engrafted with human peripheral blood mononuclear cells (PBMC), termed the hu-PBMC-NOD-scid IL2rγnull model, would provide a model that more accurately reflects human immunity in vivo than other models currently available. To investigate this possibility, we first investigated whether NOD-scid IL2rγnull mice were able to support the engraftment of human PBMC. We found that NOD-scid IL2rγnull mice engraft with human PBMC at much higher levels then the previous gold standard model, the NOD-scid mouse. We then investigated the kinetics of human cell engraftment, determined the optimal cell dose, and defined the influence of injection route on engraftment levels. Even at low PBMC input, NOD-scid IL2rγnullmice reproducibly support high levels of human PBMC engraftment. In contrast to previous stocks of immunodeficient mice, we observed low intra- and interdonor variability of engraftment. We next hypothesized that the human PBMC engrafted in NOD-scid IL2rγnull mice were functional and would reject transplanted allogeneic human tissues. To test this, human islets were transplanted into the spleen of chemically diabetic NOD-scid IL2rγnull mice with or without intravenous injection of HLA-mismatched human PBMC. In the absence of allogeneic PBMC, the human islets were able to restore and maintain normoglycemia. In contrast, human islet grafts were completely rejected following injection of HLA-mismatched human PBMC as evidenced by return to hyperglycemia and loss of human C-peptide in the circulation. Thus, PBMC engrafted NOD-scid IL2rγnull mice are able to provide an in vivomodel of a functional human immune system and of human islet allograft rejection. The enhanced ability of NOD-scid IL2rγnull mice to support human cell engraftment gave rise to the possibility of creating a model of graft versus host disease mediated by a human immune system. To investigate this possibility, human PBMC were injected via the tail vein into lightly irradiated NOD-scid IL2rγnull mice. We found that in contrast to previous models of GVHD using human PBMC-injected immunodeficient mice, these mice consistently (100%) developed GVHD following injection of as few as 5x106PBMC, regardless of the PBMC donor used. We then tested the contribution of host MHC in the development of GVHD in this model. As in the human disease, the development of GVHD was highly dependent on host expression of MHC class I and class II molecules. To begin to evaluate the extent to which the PBMC-engrafted NOD-scid IL2rγnull humanized mouse model of GVHD represents the clinical disease, we tested the ability of a therapeutic in clinical trials to modulate GVHD in these mice. In agreement with the clinical experience, we found that interrupting the TNFα signaling cascade with etanercept delayed the onset and severity of disease in this model. In summary, we conclude that humanized NOD-scid IL2rγnull mice represent an important surrogate for investigating in vivo mechanisms of both human islet allograft rejection and graft versus host disease.

GM1 gangliosidosis is an autosomal recessive lysosomal storage disease, caused by a deficiency in the enzyme β-galactosidase. The disease affects the CNS, liver, kidney, heart and skeletal system, leading to severe neurodegeneration and death. We propose to treat this disorder using ex vivo hematopoietic stem cell therapy. The effectiveness of this therapy requires the recruitment of transduced donor cells to the CNS. This is only found to occur after mice are conditioned with total body irradiation, due to the increase in CNS cytokine production and blood brain barrier permeability that occurs. As the use of total body irradiation in pediatric patients has been linked to future developmental problems, this myeloablation approach is often avoided in younger patients in favor of a conditioning regimen using the chemotherapy drugs, busulfan and cyclophosphamide. Whether donor cells can enter the CNS when a busulfan and cyclophosphamide conditioning regimen is used has not been determined. In this study we plan to quantify the cytokine and blood-brain barrier permeability increases necessary for donor cells to be recruited to the CNS after total body irradiation. We will then investigate whether busulfan and cyclophosphamide conditioning and/or the chronic neuroinflammation present in GM1 mice can produce similar conditions and facilitate the recruitment of donor hematopoietic stem cells to the CNS. Finally we will assess whether ex vivo hematopoietic stem cell gene therapy is still an effective therapy when busulfan and cyclophosphamide are used for myeloablative conditioning.

Allogeneic hematopoietic chimerism leading to central tolerance has significant therapeutic potential. Establishment of hematopoietic chimerism created by stem cell transplantation has been shown to prevent and cure a number of autoimmune diseases and induce the most robust and long-lasting form of transplantation tolerance known. However, the realization of the vast clinical potential of hematopoietic chimerism for induction of transplantation tolerance has been impeded by the toxicity of the host conditioning regimen and the development of graft-versus-host disease (GVHD). This thesis describes the development of stem cell transplantation protocols that 1) reduce the host conditioning regimen; and 2) abrogate the development of GVHD. When applied to the treatment of autoimmune diabetic NOD mice, a model of type 1 diabetes, stem cell transplantation was able to 3) prevent autoimmune recurrence; and 4) permit curative pancreatic islet transplantation. I first describe a tolerance-based stem cell transplantation protocol that combines sub-lethal irradiation with transient blockade of the CD40-CD154 costimulatory pathway using an anti-CD154 antibody. With this protocol, I established hematopoietic chimerism in BALB/c mice transplanted with fully allogeneic C57BL/6 bone marrow. All chimeric mice treated with anti-CD154 antibody remained free of graft vs.host disease (GVHD) and accepted donor-origin but not third party skin allografts. It was similarly possible to create allogeneic hematopoietic chimerism in NOD/Lt mice with spontaneous autoimmune diabetes. Pancreatic islet allografts transplanted into chimeric NOD/Lt mice were resistant not only to allorejection but also to recurrence of autoimmunity. I conclude that it is possible to establish robust allogeneic hematopoietic chimerism in sub-lethally irradiated mice without subsequent GVHD by blocking the CD40-CD154 costimulatory pathway using as few as two injections of anti-CD154 antibody. I also conclude that chimerism created in this way generates donor-specific allograft tolerance and reverses the predisposition to recurrent autoimmune diabetes in NOD/Lt mice, enabling them to accept curative islet allografts. In order to further reduce the impediments associated with the implementation of allogeneic hematopoietic chimerism as a therapeutic modality, I adapted a costimulation blockade-based protocol developed for solid organ transplantation for use in stem cell transplantation. The protocol combines a donor-specific transfusion (DST) with anti-CD154 antibody to induce peripheral transplantation tolerance. When applied to stem cell transplantation, administration of DST, anti-CD154 antibody, and allogeneic bone marrow led to hematopoietic chimerism and central tolerance with no myeloablation (i.e. no radiation) and no GVHD in 3 different strains of mice. The development of donor-specific tolerance in this system was shown to involve deletion of both peripheral host alloreactive CD8+ T cells and nascent intrathymic alloreactive CD8+ T cells. In the absence of large numbers of host alloreactive CD8+ T cells, the cell transfusion that precedes transplantation need not be of donor-origin, suggesting that both allo-specific and non-allo-specific mechanisms regulate engraftment. Agents that interfere with peripheral transplantation tolerance partially impair establishment of chimerism. I conclude that robust allogeneic hematopoietic chimerism and central tolerance can be established in the absence of host myeloablative conditioning using a peripheral transplantation tolerance protocol.

The prevalence of diabetes is approaching epidemic proportions worldwide. There is currently no cure for type 1 diabetes, and successful treatment requires constant monitoring of blood sugars and use of exogenous insulin to prevent hyperglycemia. Diabetes will be curable when pancreatic β-islet cells can be transplanted into diabetes patients without requiring long-term immunosuppression. This will require learning more about the induction of functional tolerance, a state that maintains the competence of the immune system to most antigens but protects graft-specific antigens from immune rejection, permitting transplantation. One known mechanism of peripheral tolerance is T cell anergy, a phenotype of hypo-reponsiveness in CD4+ T cells. The focus of this thesis is a description of factors shown to be specific to the induction and maintenance of T cell anergy, whose loss reverses the anergic phenotype, restoring the ability of the cells to proliferate in response to antigen. The first of these is Egr-2, a zinc-finger transcription factor, whose presence is required for the induction of anergy induced in T cell clones by TCR stimulation in the absence of costimulation. Egr-2 is shown to be important to anergy induction but not anergy maintenance. In contrast, a negative costimulation receptor, PD-1, is shown to be necessary for the maintenance of anergy. It is possible that learning more about the genetic factors that orchestrate T cell anergy will prove useful in the development of tolerance-based protocols for organ and tissue transplantation without the use of long-term immunosuppression.

Il manque actuellement aux médecins une nouvelle méthode qui rationalise le traitement peu invasif pour en faire des procédures à opérateur unique, assistées par une caractérisation précise des tissus in situ et en temps réel, en situation de prise de décisions dans la gestion du cancer colorectal. Une solution prometteuse à ce problème a été développée par l'équipe AVR (Automatique, Vision et Robotique) du laboratoire ICube, au sein de laquelle l'endoscope interventionnel flexible (fabriqué par Karl Storz) a été entièrement robotisé, permettant ainsi à un seul opérateur de télémanipuler indépendamment l'endoscope et deux instruments thérapeutiques insérables, grâce à unité de contrôle commune. Cependant, l'endoscope flexible assisté par robot est soumis aux mêmes limites de précision diagnostique que les systèmes d'endoscopie standards. Il a été démontré que l'OCT endoscopique présente un potentiel pour l'imagerie des troubles de la voie gastro-intestinale et pour la différenciation de tissus sains des tissus malades. Actuellement, l'OCT se limite à l'imagerie de l'œsophage humain, qui présente une géométrie simple et un accès facile. Ni l'OCT, ni l'endoscope robotisé ne peuvent résoudre à eux seuls les limites de la norme actuelle de soins pour la prise en charge d’un cancer du côlon. La combinaison de ces deux technologies et le développement d'une nouvelle plate-forme pour la détection et le traitement précoce du cancer constituent l'objet principal de cette thèse, avec la vision de développer une console d'imagerie OCT et une sonde de haute technologie intégrée à l'endoscope robotisé. Ce système permet d'obtenir des images de l'intérieur du gros intestin pour la caractérisation des tissus et l'assistance au traitement, permettant ainsi à un seul opérateur d'effectuer une intervention peu invasive en mode télémanipulation
There exists an unmet clinical need to provide doctors with a new method that streamlines minimally invasive endoscopic treatment of colorectal cancer to single operator procedures assisted by in-situ and real-time accurate tissue characterization for informed treatment decisions. A promising solution to this problem has been developed at the ICube laboratory, in which the flexible interventional endoscope (Karl Storz) was completely robotized, so allowing a single operator to independently telemanipulate the endoscope and two insertable therapeutic instruments with a joint control unit. However, the robot-assisted flexible endoscope is subject to the same diagnostic accuracy limitations as standard endoscopy systems. It has been demonstrated that endoscopic optical coherence tomography (OCT) has a good potential for imaging disorders in the gastrointestinal tract and differentiating healthy tissue from diseased. Neither OCT, nor the robotized endoscope can solve the limitations of current standard of care for colon cancer management alone. Combining these two technologies and developing a new platform for early detection and treatment of cancer is the main interest of this work, with the aim of developing a state-of-the-art OCT imaging console and probe integrated with the robotized endoscope. The capabilities of this new technology for imaging of the interior of the large intestine were tested in pre-clinical experiments showing potential for improvement in margin verification during minimally invasive endoscopic treatment in the telemanipulation mode

近年来，血管类疾病已经成为人类健康的第一杀手。每年有成百上千万人死于血管疾病。血管介入术是一种非常有前景的血管类疾病的治疗手段。血管介入术是一种微创手术，它已经被广泛的用于治疗中风，血管狭窄，血管瘤等疾病。相对于传统的开放式手术，它具有风险低，恢复快，住院时间短等优点。该疗法通常在透视影像的引导下由导管和导线在血管内协同完成手术过程。因为介入术的复杂性和特殊性，作为介入手术医生的必要技能，掌握手术中手眼协同，各种手术器具的使用和复杂细致的手术流程无疑是一个巨大的挑战。因此，迫切地需要一种高效、安全的训练系统。相对于传统的训练方法，基于虚拟现实技术的训练系统是一种非常好的训练手段。
为了建立一套高仿真的介入手术训练模拟器，首先，我们要为病人的血管网重建三维模型。我们提出了一种自动的提取中心线的方法，用来从分割好的CTA/MRA体数据中获取病人血管网的中心线。基于改进的平行传递算法，沿着这些中心线，生成了一系列连续的标架。根据这些标架，我们构造了血管的横截面，并在此基础上生成了光滑连续的三维血管模型。
其次，作为血管介入术中最基础和最重要的手术器械，我们为导管和导线建立了物理模型。我们提出了一种基于最小势能原理的可变形的模型用于模拟导管和导线对于受力的反应。我们还提出了一个快速并且稳定的多网格算法来保证模拟的真实性和严格的实时交互要求。另外，我们做了几组实验。通过这些实验，验证了多网格算法在稳定性、实时性、模拟的真实性等方面满足了我们对于训练用模拟系统的要求。
再次，为了模拟血管栓塞术的手术过程，我们提出了一种模拟线圈填充血管瘤的过程的新方法。通过加总线圈弯曲变形的弹性势能、血管瘤变形的弹性势能以及外力做的功，我们建立了在血管栓塞术的环境下的总势能模型。为了求解这个模型，我们提出了一个基于有限元方法的求解器。从而模拟了线圈在介入医生的操作下慢慢的进入血管瘤，并缠绕起来的过程。
另外，我们提出了一个分层圆柱网格模型（LCGM）用于模拟在血管网中血流的运动。这一模型在几何上和拓扑结构上都非常适合我们的应用。我们将血液在血管中的流动近似为一维的层流，并用一组线性等式描述了血管网中流速与血压的关系。通过求解这一线性系统，得到了在分层圆柱网格模型下血流的速度场。依据这个血流的速度场，我们采用平流-扩散模型来模拟造影剂在血管中的传播的过程。
Vascular diseases have been becoming the number one cause of death worldwide in recent years. Millions of people were killed by vascular diseases each year. An increasingly promising therapy for treating vascular diseases is Vascular Interventional Radiology (VIR). VIR is a minimally invasive surgery (MIS) procedure, which has been widely used to cure stroke, angiostenosis, aneurysm and etc. A low risk, an accelerated recovery and a shorter stay in hospital are important advantages over the traditional vascular surgery. This therapy is performed by a guidewire-catheter combination inside the blood vessels under the guidance of the fluoroscopic imaging. Because of the complexity and particularity of these procedures, it is a great challenge to master hand-eye coordination, instrument manipulation and procedure protocols for each radiologist mandatory. An efficient and safe training system is needed urgently. In contrast to these traditional training methods, virtual reality (VR) based simulation systems is a pretty good surrogate.
In order to build a high fidelity interventional simulator for physician training, firstly, we reconstructed the three dimensional (3D) model for the vascular network of the patients. An method of automatic skeleton extraction was proposed to acquire the centerline of the vascular network from the segmented volume data from CTA/MRA. A series of continuing frames were generated along with the centerline based on improved parallel transporting method. According to these frames we built the crossections of the vessels and further the 3D vascular model with the smooth meshes.
Secondly, as the most basic and important instruments in the VIR procedure, the catheter and guidewire were modeled and simulated physically. We developed a deformable model to simulate complicated behaviors of guidewires and catheters based on the principle of minimum total potential energy. A fast and stable multigrid solver was proposed to ensure both realistic simulation and real time interaction. A series of experiments were conducted to evaluate our multigrid solver in terms of stability, time performance, the capability of simulating catheter behaviors and the realism of catheter deformation.
Thirdly, to simulate the procedure of embolization, we proposed a novel method to simulate the motion of coil and their interactions with the aneurysm. We formulated the total potential energy in the embolization circumstance by summing up the elastic energy deriving from the bending of coils, the potential energy due to the deformation of the aneurysm and the work by the external forces. A novel FEM-based approach was proposed to simulate the deformation of coils. And the motion of coils and their responses to every input from the interventional radiologist can be calculated globally.
Fourthly, we proposed our Layered Cylindrical Gird Model (LCGM) for simulating blood flow in vascular network, which is pretty suitable for sampling the vascular network geometrically and topologically. The blood flow in vessels was regarded as 1D laminar flow and formulated into a set of linear equations based on the Poiseuille law to describe the relationship between the speed of flow and the pressure. Solving those equations, we got the velocity fields in the blood flow. In terms of the velocity fields, an advection-diffusion model was adopted to simulate the propagation of contrast agent with the blood flow.
Finally, all above techniques and procedures were implemented and integrated into a simulation system for training the medical students to acquire the endovascular skill, and an empirical study was also designed based on a typical selective catheteriza- tion procedure to assess the feasibility and effectiveness of the proposed system.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
最后，我们将所有以上提到的技术和方法集成到模拟系统中用于训练医学院的学生，并使他们获得血管介入术的技能。并且，我们基于一个典型的导管插入术过程，使用经验分析的方法对模拟系统的可用性和效率进行了评估。
Li, Shun.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.
Includes bibliographical references (leaves 105-116).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in also Chinese.
Abstract --- p.i
Acknowledgement --- p.vi
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Vascular Modeling --- p.14
Chapter 2.1 --- Introduction and Related Work --- p.14
Chapter 2.2 --- Vascular Skeleton Graph Construction --- p.15
Chapter 2.2.1 --- Chamfer distance transform and Dijkstra's shortest-path algorithm --- p.17
Chapter 2.2.2 --- End vertices retrieval --- p.19
Chapter 2.2.3 --- The algorithm of vascular skeleton extraction --- p.21
Chapter 2.3 --- Vascular Modeling --- p.21
Chapter 2.3.1 --- Tubular Model --- p.21
Chapter 2.3.2 --- Bifurcation Model --- p.23
Chapter 3 --- Catheter Simulation --- p.28
Chapter 3.1 --- Introduction and Related Works --- p.28
Chapter 3.2 --- Catheter Simulation --- p.31
Chapter 3.2.1 --- Kirchhoff Theory of Elastic Rod --- p.32
Chapter 3.2.2 --- Problem Formulation --- p.34
Chapter 3.2.3 --- The Multigrid Iterative Solver --- p.38
Chapter 3.3 --- Collision detection --- p.45
Chapter 3.4 --- Validation of the Catheter Simulation Method --- p.47
Chapter 3.4.1 --- Stability --- p.49
Chapter 3.4.2 --- Time Performance --- p.50
Chapter 3.4.3 --- Preservation of Curved Tip --- p.51
Chapter 3.4.4 --- The realism of catheter deformation --- p.53
Chapter 4 --- Coil Embolization Simulation --- p.59
Chapter 4.1 --- Introduction and Related Work --- p.59
Chapter 4.2 --- Methodology --- p.61
Chapter 4.2.1 --- Total potential energy of a coil --- p.61
Chapter 4.2.2 --- The FEM-based numeric solver for interactive coil simulation --- p.61
Chapter 5 --- Angiography Simulation --- p.70
Chapter 5.1 --- Introduction and related works --- p.70
Chapter 5.2 --- The Equations of Fluid --- p.72
Chapter 5.3 --- Layered Cylindrical Gird Model --- p.73
Chapter 5.4 --- Numerical Method --- p.76
Chapter 5.4.1 --- Evaluation of the velocity field of blood flow --- p.76
Chapter 5.4.2 --- Evaluation of the density field --- p.78
Chapter 5.5 --- Results --- p.81
Chapter 6 --- System Implementation and Evaluation --- p.84
Chapter 6.1 --- Introduction and Related Work --- p.84
Chapter 6.2 --- System Construction --- p.85
Chapter 6.3 --- Empirical Study of the Training System --- p.89
Chapter 7 --- Conclusion and Discussion --- p.98
Chapter 7.1 --- Geometric Modeling of Vasculature --- p.99
Chapter 7.2 --- Catheterization Simulation --- p.99
Chapter 7.3 --- Embolization Simulation --- p.100
Chapter 7.4 --- Angiography Simulation --- p.101
Chapter 7.5 --- System and Evaluation --- p.102
Publication List --- p.103
Bibliography --- p.105

Orientação: Ana Maria Duque de Araújo Munhoz ; co-orientação: Gonçalo José Carmona Santana Paixão
Este estudo incidiu sobre a avaliação do parasitismo gastrointestinal de um grupo de equinos estabulados na Escola das Armas, Mafra, por meio das técnicas de McMaster e Mini-FLOTAC, comparando os seus respetivos resultados. O estudo foi composto por 30 animais, com idades compreendidas entre os 5 e os 24 anos das raças Lusitana, Cruzada Portuguesa, Puro Sangue Inglês e Puro Sangue Árabe. O sexo predominante o masculino. O estudo decorreu num período de 4 meses, com um total de 10 análises fecais. As amostras foram submetidas as técnicas qualitativas de Willis e Sedimentação Simples e as técnicas quantitativas de McMaster e Mini-FLOTAC e coprocultura. O OPG médio anterior à desparasitação foi 472 OPG através da técnica de McMaster e 351 com a técnica de Mini-FLOTAC. Pela técnica de McMaster observou-se que 76,7% dos animais encontravam-se positivos e pela técnica de Mini-FLOTAC observou-se 93% positivos para infeção por estrongilídeos gastrointestinais. Pela técnica de McMaster foi determinado o grau de infeção por estrongilídeos: 53,3% para infeções baixas, 20% para infeções moderadas e 26,7% para infeções altas. Através da técnica Mini-FLOTAC foram observadas 66,7% de infeções baixas, 10% de infeções moderadas e 23,3% de infeções altas. A técnica de Willis confirmou a presença de ovos de estrongilídeos, enquanto a técnica de Sedimentação permitiu a identificação de ovos de Parascaris spp. e oocistos de Eimeria leuckarti. Após a desparasitação com ivermectina todos os equinos foram examinados através das técnicas de McMaster e Mini-FLOTAC para comprovação do TRCOF que resultou em 100% de eficácia pela técnica McMaster e 99,7% obtido pelo Mini-FLOTAC. As coproculturas revelaram a maior prevalência do género Cyathostomum spp. Este estudo identificou a técnica de Mini-FLOTAC como mais exata e precisa quando comparada com a técnica de McMaster.
This study focused on the evaluation of the gastrointestinal parasistism in a group of equines stabled in Escola das Armas, Mafra, using the McMaster and Mini-FLOTAC while comparing both techniques. The studied sample consisted on a total of 30 animals, aged between 5 and 24 years old, whose breeds were Lusitanos, Portuguese Cross Horses, Tthoroughbred and Arabian. The predominant gender were males. This study was developed during 4 months, with a total of 10 fecal analysis. The samples were analyzed through the Willis and Simple Sedimentation technique and also the quantitative McMaster and Mini-FLOTAC technique. In the period prior to deworming, the EGP were 472 with the McMaster technique and,351 with the Mini-FLOTAC. Using the McMaster technique 76,7% were positive for EPG while 93% were positive on Mini-FLOTAC technique. On the Mini-FLOTAC technique 66,7% were low infections, 10% were moderate and 23,3% were high. The Willis technique confirmed the presence of strongyles eggs, while the Sedimentation technique allowed the identification of Parascaris spp. eggs and Eimeria leuckarti oocysts. After the deworming with ivermectin all the equines were examined through the McMaster and Mini-FLOTAC techniques to compare the results of the FECRT (Fecal Egg Count Reduction Test) shown 100% efficacy using McMaster technique and 99,7% using the Mini-FLOTAC technique. The coprocultures revealed the prevelance of Cyathostomum spp. This study concluded that the Mini-FLOTAC is a more exact and precise technique when compared with the McMaster technique.