[Truncated abstract] The hepatitis C virus (HCV) is a significant human pathogen for which there are limited post-infection therapies and no effective vaccine. Research into HCV is notoriously difficult due to the absence of suitable in vitro and in vivo model systems with which to study the virus. Furthermore, our understanding of HCV host interaction is limited and the mechanisms by which it subverts the host immune system remains largely unknown. Due to the difficult nature associated with studying HCV, the work presented in this thesis was designed to addresses a broad range of issues relating to both clinical and molecular aspects of HCV. Chronic HCV infection is often associated with the development of cirrhosis, end stage liver disease and hepatocellular carcinoma. To date, histological examination of liver biopsies provides the only approved method with which to assess the level of liver damage. While clinically informative, liver biopsies are highly invasive and may be contraindicative for patients such as haemophiliacs. Cytokine specific ELISPOT assays were used to determine whether cytokine secretion from PBMCs isolated from chronically infected HCV patients could be used as a non-invasive method to assess liver damage. Chronically infected patients with sever liver fibrosis demonstrated a significantly reduced ability to produce IFN-γ in response to HCV Core, but not other unrelated antigens, indicating that decreased IFN-γ secretion by PBMCs in response to HCV antigen could be used as a non-invasive marker for the development of liver fibrosis ... A series of HCV expression vectors covering the full length of the HCV ORF were constructed and their expression extensively tested before being used to assess the ability of HCV proteins to interact with Jak/STAT mediated Type I IFN signalling. Additionally, an alternative set of HCV IRES-EGFP reporter vectors were developed and used to access HCV IRES functionality between different eukaryotic cell lines. HCV Core protein expressed alone or in concert with E1-P7 and non-structural protein NS5B were shown to significantly reduce Jak/STAT mediated IFN expression. While the influence of HCV Core on Type I IFN signalling is consistent with previous reports in the literature, these results identify a new role for NS5B as a possible candidate protein involved in inhibition of Type I IFN signalling.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Made available in DSpace on 2016-12-08T16:24:16Z (GMT). No. of bitstreams: 1 PGCA14MA128.pdf: 310597 bytes, checksum: a3e0e2189761ad026f58f740503dd0c2 (MD5) Previous issue date: 2014-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Due to high levels of parasite resistance to different commercial active ingredients, new control alternatives are being studied, including the phytotherapy. These measures aim to search for helper methods in the control of parasitic diseases. However, there are many products available in the market and they have no scientific proof of its efficacy or possible side effects. The objective of this study was to evaluate the hematological and hepatic effects following administration of Neem pie (Azadirachta indica) in sheep. Three strengths of Neem cake was added to the mineral salt (1, 2 and 4 %) and administered during 126 days to 32 Lacaune sheep breed, divided into four groups: three groups for different treatments and a control were tested, which received mineral salt. Blood samples were taken every 21 days to perform the complete blood count, serum total plasma protein and fibrinogen and liver biochemical evaluation. In those same times, fecal samples were collected for quantification of eggs per gram of feces (EPG). Statistical differences between times and groups for several variables were observed, but without being related to the administration of Neem pie. The results of complete blood count, measurement of total plasma protein, fibrinogen and hepatic clinical biochemistry indicated that administration of Neem pie at concentrations of 1, 2 and 4%, does not interfere in hematological values , or on the integrity and liver function Lacaune sheep breed / Devido aos altos índices de resistência dos parasitas aos diferentes princípios ativos comerciais, novas alternativas de controle vêm sendo estudadas, entre elas a fitoterapia. Essas medidas visam a busca de métodos auxiliares no controle das parasitoses, entretanto, muitos produtos estão disponíveis no mercado e não têm comprovação científica de sua eficácia ou de possíveis efeitos colaterais. O objetivo deste estudo foi avaliar os efeitos hematológicos e hepáticos após a administração de torta de Neem (Azadirachta indica) em ovinos. Foram testadas três dosagens da torta de Neem adicionada ao sal mineral (1, 2 e 4%), administradas por 126 dias para 32 ovinos da raça Lacaune, divididos em quatro grupos sendo três grupos para os diferentes tratamentos e um controle, o qual recebeu somente sal mineral. Amostras de sangue foram colhidas a cada 21 dias para realização do hemograma completo, dosagem de proteína plasmática total e fibrinogênio e avaliação da bioquímica clínica hepática. Nestas mesmas ocasiões, amostras de fezes foram coletadas para a quantificação de ovos por grama de fezes (OPG). Foram observadas diferenças estatísticas entre momentos e grupos para diversas variáveis, porém sem estarem relacionadas à administração de torta de Neem. Os resultados obtidos de hemograma completo, dosagem de proteína plasmática total, fibrinogênio e de bioquímica clínica hepática indicaram que a administração de torta de Neem nas concentrações de 1, 2 e 4%, não interfere nos valores hematológicos, nem sobre a integridade e função hepática de ovinos da raça Lacaune

No description available.

A prospective study of two combined oral contraceptives was conducted in the Sudan. No pregnancies occurred. Overall incidence of side effects was low. Headache was most frequently reported. Elevations were observed for weight, systolic and diastolic blood pressures, and SGOT and SGPT values while a decrease was seen for hemoglobin levels. Menstrual irregularities were not a problem for the users. Total 6-month use discontinuation rates were low for both pill groups.

Phenytoin is a relatively old anticonvulsant, but it has been commonly prescribed for more than half a century. The variability of phenytoin pharmacokinetic characteristics presents a challenge in therapeutic drug monitoring; hence, in the past twenty years its pharmacokinetic characteristics have been studied extensively. Up to now the studies were done with either healthy individuals or patients with normal liver functions. In this study a multifactorial scale of liver function, Pugh-Modified CTC (Child-Turcotte Criteria), has been incorporated to develop and evaluate a population pharmacokinetic model for phenytoin to be used in patients with liver dysfunction. Nonlinear Mixed Effects Model (NONMEM), a regression computer program, was utilized to develop the population pharmacokinetic model on the data of this study. The predictive performance of this model was evaluated by means of bootstrapping of the prediction error (PE) with the improved prediction-error (PE imp ) serving as an estimate of internal validity. The developed and validated final population pharmacokinetic model for phenytoin in patients with liver dysfunction is presented as follows: [special characters omitted] where Vmax is the maximum metabolic rate (mg/h); &thetas; 1 , the intercept for Vmax, is 7.41 mg/h; WT is the body weight (Kg); LS indicates one of three liver statuses: normal (CTC ≤ 6), mild dysfunction (CTC scores of 7–9), and moderate dysfunction (CTC scores of 10–12); Vd, the apparent volume of distribution (L), is 184 L; &thetas; WT is 0.126 and &thetas; LS is 2.14 for moderate liver-dysfunction. The maximum metabolic rate increased in patients with liver dysfunction, and there was weak statistical evidence that Vmax might increase in patients with chronic alcohol abuse. Based on the aforementioned longitudinal (population) pharmacokinetic model, a dosing method was also developed. By utilizing the dosing method, it may be possible to improve phenytoin dosage regimens, initial doses, and Bayesian estimates of pharmacokinetic parameters. Improved initial doses and more accurate estimates of pharmacokinetic parameters may lead to fewer required measured phenytoin concentrations and fewer dose changes. A decrease in the number of dose changes should result in less time expended in the writing and processing prescriptions and orders, and there may also be fewer wasted doses. Additionally, the improved initial doses should result in concentrations more frequently in the therapeutic window; thereby, resulting in less toxicity, greater efficacy, and improved patient compliance. All of these effects should decrease the cost of therapy in patients receiving phenytoin, a factor which is an important consideration in this age of cost containment and managed care.

Eighteen healthy dogs were divided into three equal groups. All dogs were evaluated at the beginning of the experiment with complete physical examination, complete blood count, serum alanine aminotransferase, serum alkaline phosphatase, serum bilirubin, serum albumin, sulfobromophthalein. excretion test, ammonia tolerance test, glucagon response test, portal and intraparenchymal pressures, operative mesenteric portography, and histologic assessment of hepatic tissue. The left hepatic vein was ligated in the chronic and acute dogs. The dogs had a ligature placed loosely around the left hepatic vein. Acute and control dogs were evaluated 24 hours postoperatively with the hematologic and biochemical tests listed above. Acute dogs were evaluated with portal and intraparenchymal pressure, operative mesenteric portography and histologic evaluation of hepatic tissue at 48 hours postoperatively. Chronic and control dogs were evaluated at 4 weeks postoperatively with all of the tests listed above. The results of all tests performed supported a transient hepatic congestion which resolved bv the fourth postoperative week. No longstanding effect on hepatic function was found. The conclusion of this experiment was that, in normal dogs, left hepatic vein ligation does not cause severe or permanent liver damage. These findings support a clinical trial of this procedure in patients with patent ductus venosus. / Master of Science

Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are recommended to treat patients with early or intermediate hepatocellular carcinoma (HCC). The liver maximum capacity test (LiMAx) has been supposed to predict the risk of post-interventional liver failure. We investigated the correlation of LiMAx with short term survival as primary endpoint and the occurrence of adverse events after therapy as secondary endpoint. Our study cohort prospectively included 69 patients receiving TACE (n = 57) or TARE (n = 12). LiMAx test and serological analyses were performed on the day before and 4 weeks after treatment. Hepatic and extrahepatic complications were monitored for 4 weeks. The LiMAx results were not associated with altered liver function and the occurrence of adverse events. The survival rates of patients with BCLC A with LiMAx ≤ 150 μg/kg/h were lower after 30 days (75.0 ± 15.3% vs. 100%, p = 0.011), 90 days (62.5 ± 17.7% vs. 95.8 ± 4.1%, p = 0.011) and 180 days (50.0 ± 17.7% vs. 95.8 ± 4.1%, p = 0.001) compared to those with higher LiMAx levels. The LiMAx test is not suitable to predict liver function abnormalities or the occurrence of complications 4 weeks after therapy but enables the identification of patients with early stage HCC and reduced short-term survival after treatment.

The studies presented here evaluate the biliary, parenchymal and vascular enhancement effects of two T1-shortening liver-specific contrast agents, Gd-BOPTA and Gd-EOB-DTPA, in Magnetic Resonance Imaging (MRI) of healthy subjects and of patients. Ten healthy volunteers were examined with both contrast agents in a 1.5 T MRI system using three-dimensional gradient echo sequences for dynamic imaging until five hours after injection. The enhancement of the common hepatic duct in contrast to the liver parenchyma was analyzed in the first study. This was followed by a study of the image contrasts of the hepatic artery, portal vein and middle hepatic vein versus the liver parenchyma. While Gd-EOB-DTPA gave an earlier and more prolonged enhancement and image contrast of the bile duct, Gd-BOPTA achieved higher maximal enhancement and higher image contrast for all vessels studied during the arterial and portal venous phases. There was no significant difference in the maximal enhancement obtained in the liver parenchyma. In a third study, another 10 healthy volunteers were examined with the same protocol in another 1.5 T MRI system. Using signal normalization and a more quantitative, pharmacokinetic analysis, the hepatocyte-specific uptake of Gd-EOB-DTPA and Gd-BOPTA was calculated. A significant between-subjects correlation of the uptake estimates was found and the ratio of these uptake rates was of the same magnitude as has been reported in pre-clinical studies. The procedure also enabled quantitative analysis of vascular enhancement properties of these agents. Gd-BOPTA was found to give higher vessel-to-liver contrast than Gd-EOB-DTPA when recommended doses were given. In the final study, retrospectively gathered datasets from patients with hepatobiliary disease were analyzed using the quantitative estimation of hepatic uptake of Gd-EOB-DTPA described in the third study. The uptake rate estimate provided significant predictive ability in separating normal from disturbed hepatobiliary function, which is promising for future evaluations of regional and global liver disease. In conclusion, the differing dynamic enhancement profiles of the liver-specific contrast agents presented here can be beneficial in one context and challenging in another. Diseases of the liver and biliary system may affect the vasculature, parenchyma or biliary excretion, or a combination of these. The clinical context in terms of the relative importance of vascular, hepatic parenchymal and biliary processes should therefore determine the contrast agent for each patient and examination. A quantitative approach to analysis of contrast-enhanced liver MRI examinations is feasible and may prove valuable for their interpretation.

Background Mathematical modeling combined with prior knowledge of the pharmacokinetics of the liver specific contrast agent Gd-EOB-DTPA has the potential to extract more information from Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) data than previously possible. The ultimate goal of that work is to create a liver model that can describe DCE-MRI data well enough to be used as a diagnostic tool in liver function evaluation. Thus far this goal has not been fully reached and there is still some work to be done in this area. In this thesis, an already existing liver model will be implemented in the software Wolfram SystemModeler (WSM), the corresponding modeling framework will be further developed to better handle the temporally irregular sampling of DCE-MRI data and finally an attempt will be made to determine an optimal sampling design in terms of when and how often to collect images. In addition to these original goals, the work done during this project revealed two more issues that needed to be dealt with. Firstly, new standard deviation (SD) estimation methods regarding non-averaged DCE-MRI data were required in order to statistically evaluate the models. Secondly, the original model’s poor capability of describing the early dynamics of the system led to the creation of an additional liver model in attempt to model the bolus effect. Results The model was successfully implemented in WSM whereafter regional optimization was implemented as an attempt to handle clustered data. Tests on the available data did not result in any substantial difference in optimization outcome, but since the analyses were performed on only three patient data sets this is not enough to disregard the method. As a means of determining optimal sampling times, the determinant of the inverse Fisher Information Matrix was minimized, which revealed that frequent sampling is most important during the initial phase (~50-300 s post injection) and at the very end (~1500-1800 s). Three new means of estimating the SD were proposed. Of these three, a spatio-temporal SD was deemed most reasonable under the current circumstances. If a better initial fit is achieved, yet another method of estimating the variance as an optimization parameter might be implemented.    As a result of the new standard deviation the model failed to be statistically accepted during optimizations. The additional model that was created to include the bolus effect, and therefore be better able to fit the initial phase data, was also rejected. Conclusions The value of regional optimization is uncertain at this time and additional tests must be made on a large number of patient data sets in order to determine its value. The Fisher Information Matrix will be of great use in determining when and how often to sample once the model has achieved a more acceptable model fit in both the early and the late phase of the system. Even though the indications that it is important to sample densely in the early phase is rather intuitive due to a poor model fit in that region, the analyses also revealed that the final observations have a relatively high impact on the model prediction error. This was not previously known. Hence, an important measurement of how suitable the sampling design is in terms of the resulting model accuracy has been suggested. The original model was rejected due to its inability to fit the data during the early phase. This poor initial fit could not be improved enough by modelling the bolus effect and so the new implementation of the model was also rejected. Recommendations have been made in this thesis that might assist in the further development the liver model so that it can describe the true physiology and behaviour of the system in all phases. Such recommendations include, but are not limited to, the addition of an extra blood plasma compartment, a more thorough modelling of the spleen’s uptake of the contrast agent and a separation of certain differing signals that are now averaged.