Dissertations / Theses on the topic 'Gemfibrozilo'

En el presente trabajo se han evaluado tres formulaciones para Gemfibrozilo 600 mg tableta recubierta, una realizada por compresión directa y dos por granulación húmeda, de las cuales se ha seleccionado a la formulación que cumple los parámetros establecidos para el dosaje, disolución y los factores de deferencia (F1) y similitud (F2), estos factores fueron determinados a través de la comparación por perfil de disolución con respecto al producto innovador. Se realizó el estudio de estabilidad acelerada (40ºC ± 2 ºC / 75% de humedad relativa ± 5%.), estabilidad a largo plazo (25 ºC ± 2 ºC / 60% ± 5% de humedad relativa) y estabilidad intermedia (32 ºC C ± 2 ºC / 65% de humedad relativa ± 5%. ) de la formulación que cumplió las especificaciones anteriormente mencionados, en dos tipos de empaque primario (Blister de Aluminio y PVC 250 um y 300 um) y al producto de referencia, los periodos de tiempo de los análisis fueron al iniciar el estudio de estabilidad (tiempo inicial), a los 3 meses, 6 meses y en el caso de la estabilidad a condiciones ambientales hasta los 12 meses. La metodología utilizada para el análisis fisicoquímico se basó en la Farmacopea de los Estados Unidos (USP 26 – NF 21) y la Farmacopea Británica (BP 2003) y el análisis microbiológico se basó en la European Pharmacopoeia 4ta Ed. 2002, los análisis que se realizaron en los distintos periodos de tiempo a las muestras sometidas a estabilidad fueron pruebas fisicoquímicas como: descripción, peso promedio, dureza, humedad, desintegración, disolución, dosaje y uniformidad. Finalmente por medio del estudio comparativo de los datos obtenidos del estudio de estabilidad con el producto de referencia se determinó que la formulación seleccionada para Gemfibrozilo 600 mg tableta recubierta cumple con todos los parámetros de calidad establecidos por las farmacopeas oficiales de referencia a temperaturas de almacenamiento de 25 ºC e inclusive a 32 ºC. Palabras claves: Gemfibrozilo tableta recubierta, compresión directa, granulación húmeda, estabilidad acelerada, estabilidad natural, estabilidad intermedia, factores de deferencia (F1) y similitud (F2)
Three Gemfibrozil 600 mg coated tablet formulations were evaluated, one manufactured by direct compression and two by wet granulation, it has been selected the one that fulfill the established parameters for dosage, dissolution, and the difference (F1) and similitude (F2) factors, these two factors are determined by comparison of the dissolution profile respect of the innovator product. It was developed the accelerated (40 °C ± 2 °C / 75% ± 5% relative humidity), long term (25 °C ± 2 °C / 60% ± 5% relative humidity) and intermediate (32 °C ± 2 °C / 65% ± 5% relative humidity) stability studies in two types of primary container (Aluminum blister and 250 um and 300 um PVC) and for the innovator product, the analysis was at the beginning of the stability study (zero time), in the third and sixth month and in the case of the environmental condition stability even the twelfth month. The methodology used for the physico-chemical and microbiological analysis was based on the United States Pharmacopoeia (USP 26 – NF 21) and the British Pharmacopoeia (BP 2003), the microbiology analysis was based European Pharmacopoeia 4ta Ed. 2002, the analysis that were performed to the stability-submit samples in the different periods of time were physicochemical tests: description, average weight, hardness, humidity, disintegration, dissolution, dosage and uniformity. Finally, through the comparative study of the stability data obtained with the innovator product it was determinate that the selected formulation for Gemfibrozilo 600 mg coated tablet complies all the quality parameters established by official reference pharmacopoeias at storage temperature of 25°C and even at 32 °C. Key words: Gemfibrozil 600 mg coated tablet, direct compression, wet granulation, accelerated stability, long term stability, intermediate stability, the difference (F1) and similitude (F2) factors.
Tesis

El presente es un estudio transversal, descriptivo y retrospectivo realizado en el Centro Médico Naval “Santiago Távara”, ubicado en Av. Venezuela s/n Bellavista-Callao, con el objetivo de determinar y comparar el costo-efectividad de Estatinas (Atorvastatina 20mg y Pravastatina 20 mg) frente a Gemfibrozilo 600 mg en el tratamiento de hiperlipidemia durante el período de enero 2002 a julio 2005. Se revisaron las historias clínicas de 64 pacientes hiperlipidémicos, con edades entre los 40 y 64 años de ambos sexos que acuden a los consultorios externos de Cardiología, Endocrinología, Geriatría y Medicina Interna y a quienes se les prescribió algunos de los fármacos en estudio (54 Estatinas y 10 Gemfibrozilo). Además se aplicó una encuesta a los pacientes para conocer problemas de cumplimiento de terapia. El 60% de los pacientes con indicación de Gemfibrozilo, presentan Hipertrigliceridemia asociada con alteraciones del metabolismo de glucosa, y los factores de riesgo HDL-c bajo y sobrepeso u obesidad están presentes en un 90%. Según el análisis costo-efectividad (reducción del nivel sérico de LDL-c), las Estatinas resultaron con una relación costo-efectiva de 13,76 Nuevos soles por porcentaje de reducción; y el Gemfibrozilo, no resultó efectivo no pudiéndose establecer la relación costo- efectividad. Cuando la efectividad se mide por reducción de nivel de triglicéridos, el Gemfibrozilo presentó una relación costo-efectiva de 1,74 Nuevos soles por porcentaje de reducción y las Estatinas no fueron efectivas, no pudiéndose establecer la relación costo-efectividad. Cuando la efectividad se mide por logro de objetivos terapéuticos según el Tercer Panel para Adultos (ATP III) del National Cholesterol Education Program (NCEP 2001), el Gemfibrozilo presenta una relación costo-efectiva menor (361,2 Nuevos soles por paciente), debido a su menor costo.
-- This is a transversal, retrospective, descriptive study, carried out in the Centro Médico Naval “Santiago Távara” located at Avenida Venezuela s/n, Bellavista Callao, with the purpose of determining and comparing cost-effectiveness of Statins (Atorvastatin 20 mg and Pravastatin 20 mg) against Gemfibrozil 600 mg in hyperlipidemia treatment over a period from January 2002 to July 2005. 64 patient’s clinical record revision, who suffered with dyslipidemia of both genders, who were aged from 40 to 64 years old, attending in external medical service of Cardiology, Endocrinology, Geriatrics and Internal Medicine, was carried out. In order to know patient’s problem of therapy compliance , several inquiries were carried out. In patients with Gemfibrozil prescription, 60% have hypertriglyceridemia associated with alteration of glucose metabolism. Low HDL-c and Obesity or overweight factors risk were found in 90% patients at this group. According to cost-effectiveness analyses (for LDL-c level serumal reduction.), Statins showed a cost-effectiveness ratio of 13,76 Nuevos soles for reduction percentage and Gemfibrozil were not effective , it was not able to establish its cost – effectiveness ratio. When effectiveness is measured for level reduction of triglycerides, the Gemfibrozil showed a cost–effectiveness ratio of 1,74 Nuevos soles for reduction percentage and Statins were not effective , it was not able to establish its cost – effectiveness ratio. When effectiveness is measured for therapeutic objective achievement according to Adults Third Panel ( ATP III ) of the National Cholesterol Education Program ( NCEP 2001 ), Gemfibrozil shows a minor cost – effectiveness ratio ( 361,2 Nuevos soles for patient ), due to its low cost.
Tesis

Lipids support crucial functions in teleost fish, including the production of energy; lipoproteins support the movement of lipids through the vascular system. The objective of this thesis was to determine if gemfibrozil (GEM), a mammalian PPARalpha agonist pharmaceutical, could alter the circulating lipoproteins and tissue lipid metabolism in the rainbow trout, Oncorhynchus mykiss. Injections of GEM lowered the concentration of lipoproteins and changed their size distribution, lipid and fatty acid content. These changes were associated with an increased lipoprotein lipase transcript level but not activity. GEM increased liver size but did not affect its lipid content nor the activities or transcript levels of its PPARs and mitochondrial/peroxisomal enzymes. This thesis provides evidence that the pharmacological effects of GEM are conserved across vertebrates. Furthermore, the decreased plasma lipids and altered lipoprotein composition demonstrated here may be relevant sublethal indicators of exposure to PPARalpha agonists present in the aquatic environment.

Mestrado em Biologia Molecular e Celular
Over the last years, animal personality has been gaining a lot of attention from the scientific community, and, at the moment, it is being questioned its importance in survival and the evolution of species in stress situation. Between all of potential stress agents, there are emerging environmental contaminants, such as, pharmaceuticals. However, there are not many behavior and personality studies in fish. The present work aims to increase the knowledge of how factors associated with personality can influence the response to pharmaceuticals detected in the environment. For model organism, the zebrafish (Danio rerio) was chosen, and 8 months old organism were selected. Animals were separated, based on behavior responses, in two classes, bold and shy. After the selection, organisms were exposed, during 96h to a human drug, gemfibrozil, used as a lipid regulator. During the experimental assay, behavior parameters that allowed to evaluate the capacity of response to stimuli, and memory to adaptation were assessed. After 96h of exposure, associated parameters and oxidative stress were equally assessed. Bold fish traveled a bigger distance than shy fish. Furthermore, shy fish expressed higher LPO levels than bold fish, and fish from the control group, as well as, shy fish exposed to the lowest concentration of gemfibrozil expressed more LPO than shy fish exposed to the higher concentrations of gemfibrozil
Nos últimos anos, a personalidade animal tem vindo a atrair a atenção da comunidade científica, estando neste momento a ser questionada a hipótese de da sua importância na sobrevivência e a evolução das espécies em situação de stress. De entre os diferentes potenciais agentes causadores de stress estão os contaminantes ambientais emergentes como, por exemplo, os fármacos. No entanto não existem muitos estudos de comportamento e personalidade dos peixes. Este trabalho visou aumentar o conhecimento de como fatores associados a personalidade podem influenciar a resposta a fármacos detetados no ambiente. Como organismo modelo foi escolhido o peixe zebra (Danio rerio), tendo sido selecionado organismos com 8 meses. Os animais foram separados, com base em resposta comportamentais, em duas classes, proativos e reativos. Após a separação, os organismos foram expostos, durante 96h a um fármaco humano, gemfibrozil, utilizado como regulador lipídico. Ao longo do ensaio experimental foram avaliados parâmetros comportamentais que permitiram avaliar a capacidade de resposta a estímulo, memória a adaptação. Ao fim de 96 h de exposição, parâmetros associados e stress oxidativo foram igualmente avaliados. Os peixes proativos percorreram uma maior distância que os peixes retroativos. Para além disso, os peixes retroativos expressaram níveis maiores de LPO que os peixes proativos, e os peixes retroativos do controlo e expostos à menor concentração de gemfibrozil expressaram mais LPO que os peixes retroativos expostos às concentrações maiores de gemfibrozil.

FUNDAMENTO: O suco de laranja (Citrus sinensis) é rico em vitami-na C, folatos e seu principal flavonóide, a hesperidina, cuja conformação es-pacial é semelhante à genisteína de soja que tem ação favorável sobre o aparelho cardiovascular. A vitamina C é conhecida como potente inibidor da peroxidação lipídica. Mas sua capacidade por possuir efeitos terapêuticos no tratamento da aterosclerose é pouco estudada. OBJETIVO: O presente tra-balho visa a determinar se o suco de laranja pode ter efeito aditivo no trata-mento com estatinas e fibratos, reduzindo placas ateroscleróticas e a quanti-dade de LDL Oxidado (LDL ox). MÉTODOS: Análise do efeito do suco nas dimensões de cortes histológicos e na quantidade de anticorpos anti LDL oxidado (antiLDLox) em lesões ateroscleróticas na aorta de coelhos. RE-SULTADOS: O suco de laranja potencializou a redução de área de placas ateroscleróticas e a quantidade de LDL(ox) em relação às reduções obtidas com rosuvastatina e gemfibrozil. CONCLUSÕES: O suco de laranja tem efei-to sinérgico ao tratamento convencional da aterosclerose de coelhos
Statins and fibrates have been used as anti-atherosclerotic drugs. However, a high number of treated patients still present acute events and death by atherosclerotic complications. Flavonoid ingestion has been associ-ated with lower risk of death, lower incidence of coronary artery disease and more preserved endothelial function in atherosclerotic patients. Orange juice is rich in C vitamine, a well known potent inhibitor of lipidic peroxidation, and in flavonoids, mainly the hesperidine that seems the soy bean genisteine, which is associated with decrease LDL and increase HDL. Objective: In this work we studied if orange juice has addictive effect to statin and gemfibrozil in the treatment of rabbit atherosclerosis, reducing plaque area and oxidate LDL (LDLox). Methods: Five group of atherosclerotic rabbits, fed with 1% cholesterol enriched diet during 12 weeks, were analyzed: GI - received no treatment, GII Gemfibrozil 600mg/day, GIII treated with Gemfibrozil 600mg/day + orange juice, GIV - rosuvastatin/10mg / day and GV - rosu-vastatin/10mg / day + orange juice. The most severe atherosclerotic cross section in ascendant aorta was analyzed in H&E and anti-oxidated LDL (oxLDL) immunostained slides, obtaining intimal area, total vessel area, % luminal obstruction and % oxLDL area in intima. Results: The means (stan-dard deviations) of plaque area and % plaque area of oxLDL in GI were 1.05 (0.91) and 0.12 (0.13), with no significant difference with GII animals, respec- tively 3.85 (5.27) and 0.18 (0.22), but significantly reduced in GIII, 0.64 (1.56) and 0.03 (0.05). Similar data were seen in GIV, 2.11 (2.77) and 0.19 (0.25), compared with GV, 0.04 (0.09) and 0.00 (0.00). Conclusion: This work de-monstrates that orange juice has a potential synergistic action with statin and fibrates in reducing atherosclerosis and the mechanism seems to involve in-hibition of oxLDL concentration and migration of smooth muscle cells in the subendothelial space

In vivo studies of hepatobiliary disposition are challenging. The hepatobiliary system is complex, as its physiological localization, complex cellular structure with numerous transporters and enzymes, and the interindividual variability in protein expression and biliary flow will all affect the in vivo disposition of a drug under investigation. The research included in this thesis has focused on the involvement of hepatic transport proteins in the hepatobiliary disposition of rosuvastatin. The impact that several transport inhibitors had on the pharmacokinetics of rosuvastatin was investigated in healthy volunteers and in pigs. The effects were considerable, following inhibition of sinusoidal transport proteins by cyclosporine and rifampicin. These inhibitors significantly reduced the hepatic extraction of rosuvastatin by 50 and 35%, respectively, and the plasma exposure increased by factors of 9.1 and 6.3, respectively. Drug-drug interactions (DDI) resulting in markedly higher plasma exposures are important from a drug safety perspective as increased extrahepatic exposure of statins is associated with an increased risk of severe side-effects, such as myopathy which in rare cases could develop into rhabdomyolysis. The DDI caused by cyclosporine and rifampicin can probably be attributed to inhibition of hepatic uptake transporters. In contrast, inhibition of canalicular transporters by imatinib did not significantly affect the pharmacokinetics of rosuvastatin, which suggests that the intracellular concentration of the inhibitor in the hepatocyte was insufficient to affect the transport of rosuvastatin, or that imatinib is not a sufficiently potent inhibitor in vivo. Furthermore, gemfibrozil administered as a single dose into the jejunum in healthy volunteers and pigs did not affect the plasma or biliary pharmacokinetics of rosuvastatin. The previously reported DDI in humans upon repeated dosing with gemfibrozil might be explained by the accumulation of metabolites able to affect the disposition of rosuvastatin. The investigations presented in this thesis conclude that transport proteins are of considerable importance for the hepatobiliary disposition of rosuvastatin in vivo. The Loc-I-Gut catheter can be applied for the investigation of biliary accumulation and to determine bile specific metabolites, however it has limitations when conducting quantitative measurements. In the porcine model, hepatic bile can be collected for up to six hours and enables the determination of the hepatic extraction in vivo.

碩士
國立成功大學
化學工程研究所
82
2,2-dimethyl-5(2,5-xylyloxy) valeric acid, known as gemfibrozil, and used for treatment or prevention of arteriosclerosis, can be produced by these ways: (1) Abstraction of proton from Me2CHCOPh using NaNH2 followed by alkylation with Br(CH2)3Cl resulted in Cl(CH2)3CMe2COPh(b). Refluxing b with anhydrous K2CO3,KI and 2,5-xylenol in a medium polar solvent gave 2,5-Me2C6H3O(CH2)3CMe2COPh. The latter was heated with KOCMe3 in anisole to yield gemfibrozil. The results from GC-MASS, NMR, EA and IR comfirmed the presence of product. The overall yield was 15.97%. Although the result was not good, however we have understood some key points about the synthesis. (2) Abstraction of proton from HCMe2COOR (R is H or alkyl) followed by alkylation with an alkyl halide, 2,5-Me2C6H3O(CH2)3 Cl, also gave Gemfibrozil。 We only suceededonce by this way.

碩士
國立臺灣大學
藥學研究所
82
Part I: A novel synthetic scheme for preparation of hypolipoprot einemic agent,gemfibrozil,is proposed.In this study using p-xyle ne and 2,5-dimethylphenol as starting materials.The significance of the synthetic process is to produce gemfibrozil end product along with 2,5-dimethylphenol, a starting material for use in the next synthetic process of gemfibrozil. Part II: Designed and synthesis a series of 2,4-diamino-6-hydroxy 5-(1-substituted-4-piperidinyl)- pyrimidine as GARFT inhibitors. These analogues were fulfill the structure requirments of being 1.lipophilic;2.2-amino-6- hydroxypyrimidine skeleton;and,3.confo rmationally similar to folic acid.Compound 4 was prepared via the route of Scheme 2.

碩士
國立臺灣大學
藥學研究所
79
Gemfibrozil 是一種血脂調節劑，結構上類似clofibrate，同是屬於fibric acid 的 衍生物。Gemfibrozil 可有效地降低血中三酸甘油酯的濃度，並增加高密度脂蛋白的 濃度；因此gemfibrozil 常被用來治療嚴重的高血脂症，以及降低因血脂異常而導致 冠狀動脈性心臟病的發生率。 胡研究指出，市面上不同配方的藥物產品對於其吸收曲線的形態有不同的影響。因此 ，本實驗即針對製劑上幾個配方因素進行研究，希望找出可能造成體內吸收差異的因 素。實驗內容主要包括體外溶離試驗，熱掃描分析試驗，以及體內吸收試驗。 影響固體劑型的釋出和吸收的因素有很多，例如：原料顆粒的大小，稀釋劑，潤滑劑 ，崩散劑及界面活性劑等。在體外溶離試驗中，乳糖、澱粉、硬脂酸、硬脂酸鎂及月 桂基硫酸鈉被採用來測試添加不同的賦形劑可能造成的影響；且藥品顆粒大小所造成 的影響亦被測試之。實驗結果顯示在不加酵素的人工腸液中，乳糖、澱粉、月桂基硫 酸鈉均可增加溶離速率及溶離量；而硬脂酸或硬脂酸鎂則會降低膠囊之溶離率，尤其 對顆粒愈小者，此效應更顯著。此外，加入不同量的界面活性劑，發現並不能有效地 克服硬脂酸鎂所造成的減低效果。 熱掃描分析試驗中，藉由熱流變化峰的出現、轉移或消失，可幫助瞭解藥品與賦形劑 之間是否產生交互作用。圖譜結果顯示除了含有月桂基硫酸鈉以及含有硬脂酸鎂的配 方可能有交互作用的存在外；其他賦形劑與主成分之間皆顯現良好的相容性。至於其 交互作用之詳細原因以及配方之安定性試驗尚待進一步研究。 由體外溶離試驗中，選擇顆粒大小為200 號篩至230 號篩，含乳糖及有／無含硬脂酸 鎂的配方進行體內吸收試驗。家兔由於胃排空難以控制，且物質停留在胃中的時間長 ，故不被認為是試驗生體可用率的理想動物模式。因此本實驗採用文獻記載之胃排空 控制兔為動物模式，探討口服製劑的吸收，以期較能模擬人體情況。 體內試驗之血中濃度分別以電腦程式LAGRAN及PCNONLIN處理，以求得藥動學參數，然 後再以ANOVA 做統計之分析。結果顯示血中最高濃度(Cmax)、到達血中最高濃度的時 間(Tmax)、吸收速率(Ka)及平均滯留時間(MRT) 皆不呈有意義的差異，但濃度－時間 曲線下的面積(AUC) 即有差異。雖然統而言之，並不呈很明確的差異，但配方中可能 存在的不相容性，仍應儘可能避免之。

碩士
國立陽明大學
藥理學研究所
104
Background: Drug-drug interaction (DDI) is defined as the change of pharmacodynamics or pharmacokinetics of a drug by prior administration or coadministration of another drug. DDI may cause adverse drug events (ADEs). The computerized drug-interaction alert system (DIAS) may reduce the occurrence of DDIs. Contraindicated repaglinide and gemfibrozil interaction alert was implemented in DIAS at a medical center since 2004. When physicians issued the prescriptions with both repaglinide and gemfibrozil, the alert automatically popped out the warning details: “gemfibrozil inhibits metabolism of repaglinide and obviously enhances the blood glucose-lowering effect, resulting in severe hypoglycemia.” The first part of the study was to investigate the effectiveness of repaglinide-gemfibrozil interaction alert and to analyze the alert rate, overridden rate and physicians’ responses to alert. The second part was to follow up the ADEs of hypoglycemia among patients with concomitant use repaglinide and gemfibrozil. Method: We conducted a retrospective descriptive study to investigate the effectiveness of repaglinide-gemfibrozil interaction alert. The ambulatory prescriptions including repaglinide or gemfibrozil from computerized physician order entry system and the prescriptions with repaglinide-gemfibrozil interaction alert from DIAS were collected at a medical center from January 1 2007 to December 31 2014. Furthermore, we conducted a case series study based on reviews of charts. We collected blood glucose levels and related information of ambulatory patients who concomitant used repaglinide and gemfibrozil at the same medical center from January 1 2007 to September 30 2015. Result: During the 8-year study period, 101,422 prescriptions involving repaglinide or gemfibrozil were prescribed for 9,197 patients. A total of 61 patients (0.66%, 61/9197) received 332 prescriptions with repaglinide-gemfibrozil interaction alert. Of these, 310 alerts for 44 patients (72.1%, 44/61) were overridden. In respond to alerts, dose or frequency of gemfibrozil was reduced in 2 prescriptions (0.64%, 2/310) with overridden alert. Among the 22 prescriptions with accepted alert, gemfibrozil was shifted to another lipid-lower drug in 9 (40.9%, 9/22), repaglinide was shifted to another oral antidiabetic drugs in 8 (36.4%, 8/22) and gemfibrozil or repaglinide was canceled in 5 (22.7%, 5/22). A total of 48 patients used repaglinide and gemfibrozil concomitantly. Over the entire 14,198-day observation time, 8 patients with 20 hypoglycemic events were detected. The incidence of hypoglycemia owing to concomitant use repaglinide and gemfibrozil was 1.41 events/1,000 patient-days (20/14,198). Conclusion: Repaglinide-gemfibrozil interaction-induced hypoglycemic events certainly existed in clinical practice. To ensure drug safety, concomitant use of repaglinide and gemfibrozil should be avoided.

Pharmaceutically active compounds (PhACs) have been found in wastewater effluents and receiving waters around the world. As yet there are no jurisdictions that regulate their release, or their impact on receiving water ecosystem health. The issue is complex due to the number of PhACs that exist, the variability in their structure and function, the variability in removal during different wastewater treatment processes, the potential for formation of metabolites and transformation products, and a lack of information on the impacts due to their presence on receiving waters. Gemfibrozil is a lipid regulating drug that is commonly found in wastewater effluents and receiving waters. It has been shown to partially degrade during biological wastewater treatment processes and has also been shown to produce reaction products through reactions with free chlorine. This thesis investigated the removal and transformation of gemfibrozil through several different wastewater treatment processes, namely biological removal and chlorination. Reactions between gemfibrozil and free chlorine led to the identification of four reaction products. The structures of three of the four reaction products were elucidated. The kinetics of formation of these reaction products were then investigated at a range of pH values, and in two wastewater matrices. One reaction product, 4’-ClGem was shown to form under conditions relevant to wastewater treatment. The impacts of gemfibrozil and 4’-ClGem presence on the abundance of suspended and biofilm bacteria in a simulated receiving water experiment were evaluated. It was shown that changes in the water matrix had more of an impact on bacterial abundance than presence of gemfibrozil or 4’-ClGem. A bacterial dose-response experiment showed a negative response at 10 mg/L exposure to 4’-ClGem, which is orders of magnitude higher then what would be found in receiving waters. In order to prevent the formation of chlorinated reaction products, it is necessary to remove gemfibrozil prior to disinfection. Recirculating biofilters (RBS), a biological technology for onsite or small-scale wastewater treatment, were explored as a potential treatment process for gemfibrozil removal. Results indicate that RBFs show promise as a robust technology to remove greater than 50% of influent gemfibrozil.

碩士
國立臺灣大學
化學工程學研究所
96
The particle sizes of the pharmaceutical substances are important for their bioavailability, which can be improved by size reduction. In this study, Gemfibrozil, Lidocaine, and Ethosuximide were micronized using the rapid expansion of supercritical solution (RESS) technique. It is found that Gemfibrozil were heterogeneous under certain operational conditions of the RESS process. This phenomenon was explained by phase equilibrium theory. Under modified conditions, the dispersible and micronized gemfibrozil particles were successfully obtained. The effects of extraction temperature, extraction pressure, pre-expansion temperature, post-expansion temperature, and nozzle diameter on the size and morphology of the micronized Lidocaine and Ethosuximide which were further investigated. The crystal habit and polymorphism behavior for Ethosuximide were modified after the RESS process. Finally, Tolbutamide was studied which had an extremely low solubility in supercritical carbon dioxide. Solid co-solvent menthol was used for the micronization of Tolbutamide. The solid co-solvent hindered the particle growth and results in Tolbutamide particle with smaller mean size and polymorphism behavior from form I to form II. Evaluation and comparison of dissolution profile for the original and RESS processed pharmaceutical compounds were investigated. Significant enhancement of dissolution rates for all micronized pharmaceutical compounds was observed.

碩士
國立陽明大學
藥理學研究所
104
Background: Gemfibrozil, a lipid lowering agent belonging to the fibric acid derivates, is a strong cytochrome P450 2C8 (CYP2C8) inhibitor. Repaglinide, an oral antidiabetic drug belonging to meglitinides category, is metabolized by CYP2C8 and CYP3A4. Recent studies indicated that concomitant use of gemfibrozil and repaglinide would markedly enhanced and prolonged the blood glucose-lowering effect of repaglinide, and might increase risk of severe hypoglycemia, a life-threatening adverse effect. Therefore, in 2003 the Ministry of Health and Welfare in Taiwan announced that the combination of gemfibrozil and repaglinide is contraindicated. However, the use of gemfibrozil-repaglinide co-medication still exists in clinical practices. This study aimed to investigate the ambulatory prescription trends of gemfibrozil-repaglinide co-medication in Taiwan during 2000-2011, explore the characteristics of co-medicated prescriptions, and observe whether the hypoglycemic events occur during the duration of concomitant of gemfibrozil and repaglinide. Methods: In this observational study, ambulatory prescriptions including gemfibrozil or repaglinide from January 1st, 2000 to December 31th, 2011 were identified by using the Longitudinal Health Insurance Database 2005. The ambulatory prescription trends of gemfibrozil-repaglinide co-medication were analyzed by simple linear regression. Furthermore, the study investigated the co-medicated rate, co-medicated sources, characteristics of medical institutions, characteristics of physicians, and characteristics of patients. In addition, the hypoglycemic events were defined by the International Classification of Disease, 9th edition during the duration of concomitant use of gemfibrozil and repaglinide. Results: There were 774 patients with a total of 5,499 ambulatory prescriptions of gemfibrozil and repaglinide combination. The co-medicated rate were 1000/000 during 12 years and decreased from 2003 to 2011 (1130/000 in 2003 to 1000/000 in 2011, p =0.100). Among the co-medicated prescriptions, 78% were prescribed by same prescription. The co-medicated trend in medical centers revealed a significant decrease (1850/000 in 2003 to 590/000 in 2011, p =0.011), whereas the clinics showed a significant increase (450/000 in 2003 to 1240/000 in 2011, p =0.003). Moreover, the study found that the co-medicated trend in northern Taiwan, central Taiwan, eastern Taiwan, outer islands, and the top five of physician specialties that prescribed most co-medicated prescriptions did not decreased significantly. In addition, 11 pateints had emergency vists with a hypoglycemia diagnosis during the duration of concomitant use of gemfibrozil and repaglinide. Conclusion: The results showed that the trend in ambulatory prescription of gemfibrozil-repaglinide co-medication from 2003 to 2011 was not significantly decreased. Moreover, elevated co-medicated rate among clinics were still observed. The study suggests that the authorites of healthcare should promote and implement the technical supports such as drug-drug interaction alert system and PharmaCloud System. Pharmacists also have responsibilities to aggressively educate the health care professionals to prevent the gemfibrozil-repaglinide co-medication and guarantee the drug safety of patients.

by Lee Hon Kit.
Thesis (M.Sc.)--Chinese University of Hong Kong, 1998.
Includes bibliographical references (leaves 80-89).
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Lipids and Lipoproteins --- p.1
Chapter 1.1.1 --- Chemistry and Classification of Lipids --- p.1
Chapter 1.1.2 --- Lipoprotein and Apolipoprotein --- p.3
Chapter 1.1.2.1 --- Lipoprotein: Structure and Classification --- p.3
Chapter 1.1.2.2 --- Apolipoprotein: Structure and Function --- p.5
Chapter 1.1.2.3 --- Lipoprotein (a) and Apolipoprotein (a) --- p.8
Chapter 1.1.3 --- Outline of Lipid and Lipoprotein Metabolism --- p.10
Chapter 1.1.3.1 --- Exogenous Lipid Metabolism --- p.10
Chapter 1.1.3.2 --- Endogenous Lipid Pathway --- p.13
Chapter 1.2 --- "Dyslipidaemia: Definition, Classification and Coronary Heart Disease" --- p.20
Chapter 1.2.1 --- Definition --- p.20
Chapter 1.2.2 --- Classification of Dyslipidaemia --- p.21
Chapter 1.2.3 --- Dyslipidaemia and CHD --- p.24
Chapter 1.3 --- Dyslipoproteinaemia and Atherogenesis --- p.25
Chapter 1.3.1 --- Pathology and Pathogenesis --- p.25
Chapter 1.3.2 --- Central Role of Oxidised LDL in Atherogenesis --- p.29
Chapter 1.3.3 --- LDL Heterogeneity and Atherogenesis --- p.37
Chapter 1.4 --- Management of Dyslipidaemia --- p.41
Chapter 1.4.1 --- Drug therapy --- p.43
Chapter 1.4.1.1 --- Triglyceride Lowering Drugs --- p.43
Chapter 1.4.1.2 --- Cholesterol Lowering Drugs --- p.45
Chapter 1.4.1.3 --- Combination Drug Therapy --- p.46
Chapter 1.5 --- Aims of this study --- p.49
Chapter 2. --- Materials and Methods --- p.50
Chapter 2.1 --- Materials --- p.50
Chapter 2.1.1 --- Patients and Controls --- p.50
Chapter 2.1.2 --- Drug Administration Trials --- p.51
Chapter 2.1.3 --- Blood Samples --- p.52
Chapter 2.1.4 --- Chemicals and Solutions --- p.52
Chapter 2.1.5 --- Apparatus and Equipments --- p.52
Chapter 2.2 --- Methods --- p.54
Chapter 2.2.1 --- "Serum Cholesterol, Triglyceride and High Density Lipoprotein cholesterol" --- p.54
Chapter 2.2.2 --- "Apolipoprotein AI, B-100 and Lipoprotein (a) Assays" --- p.54
Chapter 2.2.3 --- Ultracentrifugation of LDL Fraction --- p.55
Chapter 2.2.4 --- In Vitro Assessment of LDL Oxidisability --- p.55
Chapter 2.2.4.1 --- De-Salting of LDL Fraction --- p.55
Chapter 2.2.4.2 --- Continuously Diene Formation Monitoring --- p.56
Chapter 2.2.5 --- LDL Particle Size --- p.56
Chapter 2.2.6 --- Statistical Analysis --- p.57
Chapter 3. --- Results --- p.59
Chapter 3.1 --- Quantitative Measurement of apo B-100 --- p.59
Chapter 3.2 --- "Associations between Serum Triglyceride, LDL Particle Size and LDL Oxidisability" --- p.60
Chapter 3.3 --- "Effect of single drug and combination drug therapy on lipids, lipoproteins and apolipoproteins" --- p.64
Chapter 3.3.1 --- Quantitative Changes of Lipids and Lipoproteins --- p.64
Chapter 3.3.2 --- Qualitative changes of LDL particles --- p.65
Chapter 4. --- Discussion --- p.74
Chapter 4.1 --- "Associations between Triglyceride concentration, HDL Cholesterol concentration, LDL oxidisability and Particle Size" --- p.74
Chapter 4.2 --- Effects of Fluvastatin and Gemfibrozil on Combined Hyperlipidaemic Patients --- p.76

博士
國立臺灣大學
藥學系
85
This thesis containe three parts, which are (1) study on the synthesis and hypocholesteremic activities of gemfibrozil analogues , (2) design and synthesis of novel kcat type dihydrofolate reductase inhibitors and (3) study on the synthesis and cell growth inhibition of azatyrosine analogues.In the first part, a novel process for the synthesis of gemfibrozil was developed. The avoidance of using strong bases in the new process lowers the complexity and increases the safety of operation. The extensibility of this new process was proved by its use in the synthesis of new hypocholesteremic agents of the fibrate type. A series of gemfibrozil analogs were synthesized from the b-lactone and suitable nucleophiles under mild conditions. These analogues showed similar activity as gemfibrozil, upon whichthe analogues with an ethoxy group on its side chain ((+-)-6e, (+)-6e, and (-)-6e) are the most active.In the second part, a series of 5-(1-substituted-1,2,3,6- tetrahydro-pyridin-4-yl)-2,4-diamino-6-substituted pyrimidines were designed as open-ring analogues of tetrahydrofolic acid and fulfill the structural requirements of being (1) lipophilic, (2) conformationally similar to the reduced metabolites of folic acid, (3) open-ring skeleton to reduce rigidity and thus enhance the accessibility to active-site of target enzymes, and (4) activated in situ by oxidoreductive enzymes to form the2,3- dihydropyridinium moiety which might become a good Michael- acceptror and for irreversibly binding to the target enzymes. Facile electrophilic reaction of pyrimidines with piperidones was developed for the synthesis of this series of compounds. Some analogues had subjected to NCI for evaluation of cytotoxic activity against 60 different cancer cell lines.Azatyrosine has been reported to inhibit the growth of ras tansformed NIH 3T3 cells with little effect on that of non-transformed cells. Furthermore, those cells surviving azatyrosine from treatment per-manently acquired characteristics of normal phenotype. These charac-teristics of azatyrosine interested us to explore the possibility of developing novel anti-oncogenic compounds based on the structure of azatyrosine. Azatyrosine analogues prepared are (1) amide analogs (compound types I), (2) dipeptide ortripeptide mimetic prodrugs (compound types II-V), and (3) analogues with heterocycles or aromatic ring other than pyridine ring (compound types VI-XI). Compounds synthesized were subjected to screening on prostate cancer cell lines PC3, ras- transformed NIH 3T3 cell, and wild type NIH 3T3 cell for comparison of selective toxicity (SI). Compound 7f showed highest activity among all analogues tested with IC50 of 16.5*2.2 mM, a con-centration 458 fold lower than that for azatyrosine. The SI of this compoundwas 138.5, indicating its high selective toxicity on ras - transformed cells.

A bench-scale study of the degradation of four selected pharmaceuticals and personal care products (PPCPs) was carried out using UV and UV/H₂O₂ treatment employing low pressure (LP) and medium pressure (MP) lamps. The target substances included the pharmaceutical compounds ibuprofen, naproxen, and gemfibrozil, along with the bactericide triclosan. There were four main objectives of the study, as follows: to evaluate the removal of the target compounds using UV irradiation alone and UV/H₂O₂, to determine the reaction kinetics for direct and indirect photolysis of each selected compound, to determine the influence of major water quality parameters on the efficacy of treatment, and to compare the applied UV and UV/H₂O₂ doses to those that have been found to be effective for disinfection and removal of taste and odour compounds, respectively. For initial ultra-pure water experiments the target compounds were spiked at concentrations of approximately 250 µg/L (~1 µM). In latter ultra-pure water experiments and in the partially-treated water experiments, the selected PPCPs were spiked at a lower range (c~500-1000 ng/L), which is more representative of reported environmental concentrations. In an ultra-pure water matrix, a high LP fluence of 1000 mJ/cm² caused only triclosan to substantially degrade. Furthermore, with LP-UV/H₂O₂ only triclosan and naproxen had average percent removals above 60% at a typical disinfection fluence of 40 mJ/cm² with 100 mg/L H₂O₂. Complete degradation of all four compounds in ultra-pure water was achieved with very high fluences (compared to those used for UV disinfection) with MP-UV alone (at or above 1000 mJ/cm²) or with relatively high fluences for MP-UV/H₂O₂ (200-300 mJ/cm²) with 10 mg/L H₂O₂. Overall, when compared at similar applied fluences, the MP lamp was much more effective than the LP lamp. Furthermore, the addition of H₂O₂ typically increased removal rates, in some cases substantially, through formation and subsequent reaction of the PPCP with the •OH radical. When target substances were treated all together in an ultra-pure water solution, removals were lower than when they were treated independently at the same individual concentrations (~250 µg/L) this may simply have been the result of a higher total contaminant concentration in solution, which lessened the availability of the •OH radical and incident UV irradiation for degradation of all compounds. On the other hand, removals were improved when the combined target compounds were present at a lower individual concentration range (~750 ng/L), which suggests that removals may be concentration driven, with reduced matrix effects seen at lower overall contaminant concentrations. Furthermore, during the partially-treated water experiments, variability in treatment performance was observed with differing water quality; however, it was not evident which specific quality parameters influenced treatment effectiveness. On the other hand, substantial and sometimes complete, degradation of the target compounds was still seen in the partially-treated water with high MP-UV/H₂O₂ doses (e.g. 300 mJ/cm² + 10 mg/L H₂O₂ and 500 + 10 mg/L H₂O₂). For the kinetic experiments, compounds were spiked individually in ultra-pure water (c~250 µg/L = ~1µM). The photolysis of the target compounds during treatment was assumed to be a pseudo-first-order reaction. Kinetic parameters were determined for both direct and indirect photolysis for both lamps. The calculated rate constants confirmed the importance of •OH radicals for degradation of these compounds, especially for ibuprofen and gemfibrozil. For ibuprofen and gemfibrozil, direct photolysis rate constants could not be determined for LP-UV because very little degradation was seen at the fluences tested. LP-UV direct phototlysis rate constants for naproxen and triclosan were 0.0002 and 0.0033 cm²/mJ, respectively. Overall rate constants describing degradation of the four compounds due to LP-UV/H₂O₂ ranged from 0.0049 to 0.0124 cm²/mJ. All four compounds had fluence-based reaction rate constants for MP-UV indirect photolysis of approximately 0.01 cm²/mJ, while MP-UV direct photolysis rate constants ranged between 0.0007-0.007 cm²/mJ, with ibuprofen having the lowest and triclosan the highest. The overall trends were similar to those seen by other researchers for the removal of taste and odour compounds. For example, fluences required for substantial removal were much higher than typical disinfection doses, the MP lamp was more effective than the LP lamp (when compared solely on a fluence-basis), and the addition of H₂O₂ improved removals. On the whole, UV/H₂O₂ appears to be a very promising technology for the removal of these selected PPCPs during drinking water treatment, and is likely to be equally effective for other, similar contaminants.

Estuarine and coastal areas are the ultimate recipient for most contaminants, including emerging contaminants of concern such as nanoparticles (NPs) and pharmaceuticals. Gold nanoparticles (AuNPs) are used for a wide range of applications and have the potential to be extensively released into the environment. One of the fundamental requirements for the wide use of AuNPs is their presumed non-toxic and biocompatible nature, but recent studies have highlighted their possible toxicity, including oxidative stress, genotoxicity and protein modifications. These findings raise concerns about the potential impact of AuNPs on aquatic organisms and ultimately on human health. Considering the conflicting information about the toxicity of AuNPs, the relevance of their characteristics on the induced effects and the limited knowledge pertaining to any effects on marine/estuarine fish species, this thesis aimed to answer this general question: Will exposure to AuNPs affect molecular, biochemical and behavioural responses of Sparus aurata? To answer this general question, in vitro (24 h liver organ culture) and in vivo (96 h of exposure) assays were performed testing 7 and 40 nm AuNPs with either citrate or polyvinylpyrrolidone (PVP) coating, alone and combined with the pharmaceutical gemfibrozil (GEM). Tested concentrations ranged from 4 to 7200 μg.L-1 and 4 to 1600 μg.L-1 in the in vitro and in vivo assays, respectively. In vitro, oxidative stress/damage and biotransformation responses as well as genotoxicity were evaluated. In vivo, effects at different levels of biological organization (behaviour, neurotransmission, biotransformation, oxidative stress/damage, genotoxicity and proteins alterations) were evaluated. In cell culture media, the size of all tested AuNPs was altered within 12 h of incubation with the formation of aggregates/agglomerates larger than 100 nm. Aggregates/agglomerates of 7 nm polyvinylpyrrolidone coated gold nanoparticles (PVP-AuNPs) had smaller sizes and induced more effects than 7 nm citrate coated gold nanoparticles (cAuNPs) and 40 nm AuNPs. The results from S. aurata liver organ culture assays showed that AuNPs induced catalase (CAT) and glutathione reductase (GR) activities, DNA strand breaks and lipid peroxidation (LPO). In seawater, 7 nm cAuNPs, almost immediately aggregated/agglomerated and increased their sizes (160 nm), inducing more effects on S. aurata than PVP-AuNPs (7 and 40 nm), despite PVP-AuNPs observed stability. Also, 7 nm cAuNPs induced more effects than 40 nm cAuNPs which formed agglomerates/aggregates of 340 nm in seawater. In vivo, gold accumulation in S. aurata gills, liver and spleen was higher than in muscle. The observed gold accumulation was dependent on the characteristics of AuNPs, mostly on the coating, with higher accumulation after exposure to PVP-AuNPs compared to cAuNPs. Overall, induction of enzymatic (e.g. CAT, GR, glutathione peroxidase (GPx) and glutathione S-transferases (GST)) and non-enzymatic (non-protein thiols – NPT) defences was found after in vivo exposure to AuNPs, both in gills and liver. Decreased ability of S. aurata to continue swimming against a water flow, which can be considered an ecologically relevant effect of NPs exposure, was observed after 96 h AuNPs exposure. Gills and liver oxidative damage (increased LPO levels) and increased erythrocytes DNA strand breaks and frequency of nuclear abnormalities were detected after AuNPs in vivo exposure. AuNPs also induced alterations in the abundance of S. aurata liver proteins, with 7 nm cAuNPs inducing more effects than 7 nm PVP-AuNPs and 40 nm AuNPs. The analysis of the tissues responses showed that the gills of S. aurata were more sensitive than the liver, both in the single and combined exposures to AuNPs. In the in vitro and in vivo experiments, the assessment of the combined effects of AuNPs (7 or 40 nm) and GEM showed that the predicted percentages of effect (the sum of the percentage of the single exposures) were, for most of the tested endpoints, different than the observed percentages of effect, representing possible antagonistic (e.g. erythrocytic nuclear abnormalities and DNA damage) or synergistic (e.g. hepatic CAT and GR activities for 40 nm AuNPs with GEM and gills NPT content for 7 nm AuNPs with GEM) patterns. Overall, the effects of exposure to AuNPs depended on the concentration, size and coating of NPs and the presence of other contaminants. Data from the in vitro and the in vivo assays showed that the smaller AuNPs (7 nm) induced more alterations and, in terms of coating, assay specific responses were found, with PVP and citrate coating AuNPs being more biologically active in the in vitro and in vivo assay, respectively. The results showed that AuNPs are not inert, even at low concentrations as 4 μg.L-1, raising concern about its safety for use in aquaculture, biomedical applications or other areas. The findings showed that the multiparametric approach used in this thesis, integrating the evaluation of the in vivo effects of behavioural and oxidative stress/damage biomarkers, genotoxicity and proteins alterations, together with NPs characterisation and bioaccumulation, was essential to increase the knowledge about the toxicity of NPs to marine fish species. Addittionally, the liver organ culture of S. aurata was sensitive to low concentrations of the tested contaminants and could be used to differentiate responses to AuNPs with different characteristics, supporting its use as an alternative to in vivo testing.
As áreas estuarinas e costeiras são o receptor final para muitos contaminantes, incluindo contaminantes emergentes como as nanopartículas (NPs) e os fármacos. As nanopartículas de ouro (AuNPs) são usadas numa ampla gama de aplicações, podendo ser libertadas para o ambiente. Um dos requisitos fundamentais para o vasto uso das AuNPs é a sua presumível natureza não tóxica e biocompatível, embora estudos recentes tenham mostrado a sua possível toxicidade, incluindo stress oxidativo, genotoxicidade e alterações em proteínas. Estes resultados levantam preocupações acerca do impacto das AuNPs em organismos aquáticos e para a saúde humana. Tendo em conta a informação contraditória acerca da toxicidade das AuNPs, a importância das suas características nos efeitos produzidos e o conhecimento limitado acerca dos seus efeitos em espécies de peixe marinhas/estuarinas, esta tese teve como objetivo responder à pergunta geral: Irá a exposição a AuNPs afetar respostas moleculares, bioquímicas e comportamentais da dourada (Sparus aurata)? Para responder a esta questão, foram realizados ensaios in vitro (24 h; culturas de fígado) e in vivo (96 h de exposição) testando AuNPs de 7 e 40 nm, revestidas com citrato ou polivinilpirrolidona (PVP), individualmente e combinadas com o fármaco gemfibrozil (GEM). As gamas de concentrações testadas variaram entre 4 a 7200 μg.L-1 e 4 a 1600 μg.L-1 nos ensaios in vitro e in vivo, respetivamente. Na exposição in vitro, foram avaliados parâmetros de stress/dano oxidativo, biotransformação e genotoxicidade. In vivo, foram avaliados efeitos a diferentes níveis de organização biológica (comportamento, neurotransmissão, biotransformação, stress/dano oxidativo, genotoxicidade e alteração em proteínas). Em meio de cultura, o tamanho das AuNPs testadas alterou-se nas primeiras 12 h de incubação com a formação de agregados/aglomerados maiores que 100 nm. Os agregados/aglomerados das nanopartículas de ouro de 7 nm revestidas com polivinilpirrolidona (PVP-AuNPs) apresentaram tamanhos menores e induziram mais efeitos do que as nanopartículas de 7 nm revestidas com citrato (cAuNPs) e as AuNPs de 40 nm. Os resultados dos ensaios com culturas de fígado mostraram que as AuNPs têm a capacidade de induzir as atividades da catalase (CAT) e glutationa redutase (GR), induzir quebras na cadeia de ADN e peroxidação lipídica (LPO). Em água salgada, as cAuNPs de 7 nm, quase imediatamente agregaram/aglomeraram e aumentaram o seu tamanho (aggregados/aglomerados de 160 nm), induzindo mais efeitos em S. aurata do que as de PVP-AuNPs (7 e 40 nm), apesar da estabilidade das PVP-AuNPs neste meio. As cAuNPs de 7 nm causaram também mais efeitos do que as cAuNPs de 40 nm que formaram agregados/aglomerados de 340 nm em água salgada. In vivo, a acumulação de ouro nas brânquias, fígado e baço da dourada foi maior do que no músculo. A acumulação de ouro nos tecidos foi dependente das características das AuNPs, principalmente com o revestimento, verificando-se uma maior acumulação de ouro após exposição a PVP-AuNPs (comparando com cAuNPs). De um modo geral, a indução das defesas enzimáticas (CAT, GR, glutationa peroxidase (GPx) e glutationa S-transferases (GST)) e não enzimáticas (tióis não proteicos (NPT)) foi detetada depois da exposição in vivo a AuNPs, nas brânquias e fígado. A diminuição da capacidade natatória da dourada face a um fluxo de água constante foi observada após 96 h de exposição às AuNPs, o que pode ser considerado um efeito ecológico relevante após exposição a NPs. Dano oxidativo nas brânquias e fígado (níveis de LPO aumentados), aumento das quebras na cadeia de ADN e da frequência de anomalias nucleares nos eritrócitos foram detetados depois da exposição in vivo às AuNPs. As AuNPs induziram também alterações na abundância de proteínas presentes no fígado da dourada, com cAuNPs de 7 nm induzindo mais efeitos que as PVP-AuNPs de 7 nm e as AuNPs de 40 nm. A análise das respostas por tecido mostrou que as brânquias da dourada foram mais sensíveis do que o fígado, nas exposições às AuNPs (individuais e em combinação com o fármaco). Nos ensaios in vitro e in vivo, a avaliação dos efeitos combinados das AuNPs (7 ou 40 nm) e GEM mostrou que as percentagens esperadas de efeito (a soma da percentagem das exposições individuais) foram, para a maioria dos parâmetros avaliados, diferentes das percentagens de efeito observadas, representando possíveis padrões antagonistas – no caso das anomalias nucleares e dano no ADN dos eritrócitos, ou sinergistas – nas atividades da CAT e GR no fígado depois da exposição às AuNPs de 40 nm com o GEM e níveis de NPT nas brânquias depois da exposição às AuNPs de 7 nm com o GEM. De uma forma geral, os efeitos da exposição a AuNPs dependeu da concentração, tamanho e revestimento das NPs e da presença de outros contaminantes. Os resultados dos ensaios in vitro e in vivo mostraram que as AuNPs de tamanho menor (7 nm) induziram mais alterações e, em termos de revestimento, foram encontradas respostas específicas em cada ensaio, com o revestimento PVP e citrato a ser mais biologicamente ativo no ensaio in vitro e in vivo, respetivamente. Os resultados mostraram que as AuNPs não são inertes, mesmo a concentrações baixas como 4 μg.L-1, levantando preocupações acerca da segurança do seu uso em aquacultura, aplicações biomédicas ou outras áreas. Os resultados mostraram que a abordagem multiparamétrica usada nesta tese, integrando a avaliação de efeitos in vivo de biomarcadores comportamentais e de stress/dano oxidativo, genotoxicidade e alterações proteícas, juntamente com a caracterização e bioacumulação de NPs, foi essencial para aumentar o conhecimento acerca da toxicidade das NPs para espécies de peixe marinhas. Adicionalmente, as culturas de fígado foram sensíveis a concentrações baixas dos contaminantes testados e permitiu diferenciar as respostas a AuNPs com diferentes características, realçando o seu uso como alternativa aos testes in vivo.
Programa Doutoral em Biologia

Cell replication and division are central to the proliferation of life, and have implications for normal growth and development as well as disease state. Assembly of a complete picture of the systems which control this process requires identification of individual genetic components, but the identity and complete sequence of events that trigger initiation of cell division, at a point called START in yeast, remain unknown. Here, we evaluated panels of non-essential single gene deletion strains and tested the effects of FDA-approved drugs on cell-cycle progression, using flow cytometry to detect altered DNA content. Previous studies relied mainly on cell size changes to systematically identify genes required for the timely completion of START. This analysis revealed that most gene deletions that altered cell-cycle progression did not change cell size. Our results highlight a strong requirement for ribosomal biogenesis and protein synthesis for initiation of cell division. We also identified numerous factors that have not been previously implicated in cell-cycle control mechanisms. We found that cystathionine-beta-synthase (CBS) advances START in two ways: by promoting cell growth, which requires CBS's catalytic activity, and by a separate function which does not require that activity. CBS defects cause disease in humans, and in animals CBS has vital, non-catalytic, unknown roles. Hence, our results may be relevant for human biology. Screening chemical libraries to identify compounds that affect overall cell proliferation is common. However, it is generally not known whether the compounds tested alter the timing of particular cell-cycle transitions. Our approach revealed strong cell-cycle effects of several commonly used pharmaceuticals. We show that the antilipemic gemfibrozil delays initiation of DNA replication, while cells treated with the antidepressant fluoxetine severely delay progression through mitosis. We discovered a strong suppressive interaction between gemfibrozil and fluoxetine. The novel interaction between gemfibrozil and fluoxetine suggests that identifying and combining drugs that show cell-cycle effects might streamline identification of drug combinations with a pronounced impact on cell proliferation. Our studies not only transform our view of START, but also expand the repertoire of genetic and chemical means to modulate the eukaryotic cell cycle.