Hepatocellular carcinoma (HCQ is one of the commonest cancers worldwide. There is, however, a marked geographical variation in incidence and it has been suggested that the pathogenesis may vary in different parts of the world. A retrospective analysis of 110 HCC patients was initially undertaken which confirmed that only 29% of British patients had markers of hepatitis B infection, suggesting a possible role for other environmental agents in the pathogenesis, and that 80% of patients had underlying cirrhosis. The nature of the strong relationship between HCC and cirrhosis has not been established but it has been postulated that increased hepatocyte turnover in the cirrhotic liver may predispose to DNA damage by environmental mutagens. Cell proliferation is required to express the strongly promutagenic DNA base lesion 0'-methylguanine, produced by alkylating agents, as a mutation. &- methylguanine is repaired by the DNA repair enzyme 06-methylguanine-DNA methyltTansferase (06-MT). A microassay was developed which could reliably measure 06-MT levels in liver biopsy samples. Using this approach 06-MT levels were found to be significantly lower in cirrhotic liver when compared to non-cirrhotic and normal liver tissue. No correlation was found between lymphocyte and liver levels from individual patients with liver disease indicating that the deficiency in DNA repair is disease-a nd tissue-specific. Three polyclonal antibodies were subsequently raised to 06-MT peptides and characterised by immunoblotting in an attempt to establish the tissue distribution of the enzyme in liver. Although none of the antisera were able to detect &-MT in tissue sections they were used to analyse structural differences in the enzyme between cirrhotic and non-cirrhotic liver using SDS-PAGE followed by immunoblotting and fluorography. A band of M, 24,000r,e presentingn ative enzyme, was visualised by fluorography in all liver extracts. Densitometry of these bands correlated with the enzyme activity determined by the direct enzyme assay, validating the assay findings. Other small molecular weight bands were seen in all liver extracts and comparison with immunoblots suggested that these bands represent C-terminal truncated enzyme. The spectrum of smaller molecular weight enzyme forms was similar in cirrhotic and non-cirrhotic liver. It was, thus, concluded that although 06-MT levels were lower in'cirrhosis this was not accounted for by structural differences in the enzyme. DNA mutations (G to A) produced by the failure to repair 06-methylguanine are known to activate oncogenes and turnour suppressor genes such as p53. However only 5/55 (9%) of HCC expressed mutant p53. Other factors potentially involved in hepatocarcinogenesis include the growth factor TGF-a and a growth factor receptor encoded by the c-erb B-2 proto-oncogene. Expression of TGF-a and the C-erbB -2 oncoprotein were seen in 8/28 (28%) and 2/26 (8%) of HCC respectively, findings which differ from those observed in HCC from the Far East. Deficient DNA repair by &-MT provides one possible reason why cirrhosis is an important risk factor for the development of HCC. However, failure to repair 06-mothylguanine does not result in mutations within the p53 gene in British HCC. Furthermore, the finding of low expression of mutant p53, TGF-a and the c-erb B-2 oncoprotein in HCC from Britain compared to HCC from the Far East and Africa suggests geographical differences in the molecular mechanisms involved in hepatocarcinogenesis between areas of high and low HCC prevalence.

Patients with liver cirrhosis are susceptible to fungal infections. Due to low sensitivity of culture-based methods, we applied a real-time PCR assay targeting the 18S rRNA gene in combination with direct sequencing and terminal-restriction fragment length polymorphism (T-RFLP) in order to establish a novel tool to detect fungal DNA and to quantify and differentiate Candida DNA, also in polyfungal specimens. In total, 281 samples (blood n=135, ascites n=92, duodenal fluid n=54) from 135 patients with liver cirrhosis and 52 samples (blood n=26, duodenal fluid n=26) from 26 control patients were collected prospectively. Candida DNA was quantified in all samples. Standard microbiological culture was performed for comparison. Blood and ascites samples, irrespective of the patient cohort, showed a method-independent low fungal detection rate of approximately 1%, and the Candida DNA content level did not exceed 3.0x101 copies ml-1 in any sample. In contrast, in duodenal fluid of patients with liver cirrhosis high fungal detection rates were discovered by using both PCR- and culture-based techniques (81.5% vs. 66.7%; p=0.123) and the median level of Candida DNA was 3.8x105 copies ml-1 (2.3x102-6.3x109). In cirrhosis and controls, fungal positive culture results were confirmed by PCR in 96% and an additional amount of 44% of culture negative duodenal samples were PCR positive. Using T-RFLP analysis in duodenal samples, overall 85% of results from microbial culture were confirmed and in 75% of culture-negative but PCR-positive samples additional Candida species could be identified. In conclusion, PCR-based methods and subsequent differentiation of Candida DNA might offer a quick approach to identifying Candida species without prior cultivation.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

published_or_final_version / Physiology / Master / Master of Philosophy

Individuals with chronic liver disease experience progressive muscle wasting, weakness, fatigue, and decreased quality of life. Liver transplantation is the only treatment for end-stage liver disease with cirrhosis; however, muscle wasting, strength impairments, activity limitations, and health related quality of life do not return to the level of healthy adults. Currently there is no plan of care for rehabilitation of individuals post-liver transplantation. These individuals are only instructed to gradually increase walking and activity. Walking may increase lower extremity muscle strength; however, walking at a self-selected pace is less effective than resistance exercise. The purpose of this dissertation was to compare the benefits of a home exercise program of targeted lower extremity resistance exercise with benefits of progressive walking in individuals who have undergone liver transplantation. In Chapter 2 we performed a study to validate the ability of several outcome measures to detect changes in strength and activity performance in the population with liver disease and post-liver transplantation. The strength impairment measures of Grip Strength, Heel Rising, and Bridging along with activity limitation measures 30 Second Chair Stand and Six Minute Walk Test (6MWT) were able to differentiate strength and activity performance across levels of liver disease severity including post liver transplantation. Liver disease severity was moderately correlated with the strength impairment measures Bridging and Heel Rising but was not correlated with Grip strength. Liver disease severity was moderately correlated with 6MWT and 30-Second Chair-Stand but was not correlated with the SF-36 physical function scale. Strength impairment measures were strongly correlated with the activity limitation measures. Heel Rising and Bridging were strongly correlated with 30-Second Chair-Standing and 6MWT. Grip strength was moderately correlated with 30-Second Chair-Standing. In Chapter 3 we conducted a randomized controlled trial to assess the benefits of resistance exercise to progressive walking as a treatment plan for improving strength and activity performance in individuals post liver transplantation. We also examined the relationships of the change in muscle strength to the change in activity performance. Both the exercise and walking groups improved in strength and activity performance; however, the group performing the resistance exercise improved more. Bridging, 30 Second Chair Standing, Heel Rising, and 6MWT increased more for the exercise group than the walking group. Additionally, changes in strength were related to the changes in activity performance and health related quality of life. Bridging was correlated with Heel Rising, 30 Second Chair Standing, 6MWT, and the Chronic Liver Disease Questionnaire. In Chapter 4 we discuss the clinical relevance of the results of the studies described in the above chapters. We conclude Bridging, Heel Rising, 30 Second Chair Standing, and 6MWT are valid outcome measures to measure changes in strength and activity performance in the population with liver disease. Individuals post liver transplantation improve in strength and activity performance through progressive walking; however, the addition of resistance exercise to the current treatment plan is necessary for greater improvement. Additionally it is clinically relevant that this population was adherent to a home exercise program. Subjects adherent to the exercise program increased in strength and activity performance greater than subjects who were non-adherent.

No description available.

No description available.

Thesis--University of Helsinki. / Includes bibliographical references.

Thesis--University of Helsinki. / Includes bibliographies.

Orientador: Maria Aparecida Mesquita / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-09T19:06:25Z (GMT). No. of bitstreams: 1 Cruz_CristianeKibuneNagasakoVieirada_M.pdf: 1050615 bytes, checksum: 568a2814333ee1681714d9d75ec14548 (MD5) Previous issue date: 2007 / Resumo: A disfunção autonômica (DA) parece ser freqüente na cirrose hepática (CH) de etiologia alcoólica, enquanto que os dados referentes à prevalência e repercussões clínicas desta complicação na cirrose de etiologia não alcoólica são controversos. Existem evidências na literatura de que o método da análise da variabilidade da freqüência cardíaca (VFC) em 24 horas é mais sensível que a pesquisa dos reflexos cardiovasculares para a avaliação da função autonômica. Esta técnica foi pouco utilizada na investigação de pacientes com CH. Estudos prévios em cirróticos demonstraram a presença de alterações da motilidade intestinal que predisporiam à ocorrência de supercrescimento bacteriano. Os mecanismos responsáveis por estas alterações não foram ainda esclarecidos. Considerando que o sistema nervoso autônomo (SNA) participa do controle da motilidade intestinal, parece provável que a DA esteja associada com as alterações da motilidade intestinal na CH. Os objetivos deste estudo foram investigar a presença de alterações do SNA parassimpático e simpático em pacientes com CH de etiologia não alcoólica, utilizando os métodos dos testes de reflexos cardiovasculares e da análise da VFC em 24 horas, e avaliar a associação das alterações autonômicas encontradas com a gravidade da disfunção hepática, com alterações do trânsito intestinal, e com o aparecimento de complicações da CH. Foram estudados trinta e quatro pacientes com diagnóstico de CH de etiologia não alcoólica, divididos em Child-Pugh A (13) e Child-Pugh B/C (21). A atividade autonômica foi avaliada através dos testes de reflexos cardiovasculares e da análise da VFC em 24 horas. O estudo do tempo de trânsito orocecal (TTOC) foi realizado pelo teste do H2 no ar expirado, após ingestão de lactulose. De acordo com os testes de reflexos cardiovasculares, a presença de disfunção parassimpática foi encontrada em 4 pacientes Child A (30,8%) e em 6 pacientes Child B/C (28,4%; p>0,05). A análise da VFC em 24 horas mostrou que os parâmetros relacionados com a atividade parassimpática (LF, lnLF, pNN50) e simpática (LF, lnLF) estavam significativamente (p<0,05) diminuídos nos pacientes Child B/C, tanto em relação ao grupo controle, como também em relação aos pacientes Child A. A avaliação individual mostrou a presença de disfunção parassimpática em 3 pacientes Child A (23,1%) e em 12 (57%; p=0,07) Child B/C. A diminuição da atividade simpática concomitante foi encontrada em 8 dos 12 pacientes Child B e C, com lesão parassimpática. Em relação ao TTOC, não houve diferença estatística entre os valores do TTOC no grupo Child A (52±17 minutos) e no grupo controle (52±13 minutos). Em contraste, os pacientes Child B/C apresentaram valores mais altos do TTOC (71±34minutos) em relação aos controles (p=0,02). Apenas dois pacientes apresentaram resultados sugestivos de supercrescimento bacteriano. O tempo de seguimento foi de 19±12 meses. Ao final do estudo, cinco pacientes (24%) Child B/C evoluíram para óbito. Os valores dos parâmetros representativos da atividade parassimpática (HF, lnHF) nesses pacientes foram significativamente (p=0,04) menores que os encontrados nos pacientes do grupo Child B/C que continuavam vivos. A encefalopatia foi a complicação mais freqüente, acometendo 42,8% dos pacientes durante o período de seguimento. Houve associação estatística entre a presença de DA e a incidência de encefalopatia hepática (p<0,05). Não houve correlação entre os parâmetros da atividade autonômica com os valores do TTOC. Também não houve associação entre TTOC prolongado e complicações da CH. Em conclusão, nossos resultados demonstraram que a DA é achado freqüente nos pacientes com CH de etiologia não alcoólica e está associada com o grau de disfunção hepática, sendo mais freqüente nos pacientes com CH Child B e C. Nossos dados não demonstraram associação entre a alteração da função autonômica e o prolongamento do trânsito intestinal observado nesses pacientes. A presença da DA é um fator predisponente para a ocorrência de encefalopatia hepática, e parece influir no prognóstico da doença / Abstract: Autonomic dysfunction (AD) is common in patients with alcoholic hepatic cirrhosis but information on its occurrence and clinical relevance in patients with non-alcoholic liver disease is contradictory. 24-hour heart rate variability (HRV) is considered to be more sensitive than the cardiovascular reflexes to detect autonomic damage. Only a few studies used this technique in the investigation of autonomic function in cirrhotic patients. Previous studies have demonstrated that intestinal transit is delayed in patients with cirrhosis, and that this alteration predisposes to bacterial overgrowth, bacterial translocation and risk of infections. The reasons for that remain unclear. Since the autonomic nervous system participates in the regulation of gastrointestinal motility, it seems likely that AD may play a role in the intestinal motility alterations observed in cirrhosis. Therefore, our aims were to assess autonomic function in patients with non-alcoholic hepatic cirrhosis, and to investigate the relationship of AD with severity of disease, delayed intestinal transit and the clinical outcome. Thirty four patients with non-alcoholic hepatic cirrhosis classified as Child¿s A (n=13) and Child¿ B/C (n=21) were studied. Autonomic function was assessed by using standard cardiovascular reflexes tests and 24- hour HRV analysis. Orocaecal transit time (OCTT) was measured using the lactulose hydrogen breath test. According to cardiovascular reflexes tests, 4 patients Child A (30.8%) and 6 patients Child B/C (28.4%), were found to have evidence of parasympathetic damage. The 24-hour HRV analysis showed that parameters reflecting parasympathetic (HF, lnHF, pNN50) and sympathetic (LF, lnLF) function were significantly decreased (p<0,05) in comparison with both controls and Child¿s A patients. Individual analysis showed parasympathetic damage in three patients Child A (23,1%) and in 12 (57%) Child B/C (p=0.07). Eight patients had combined sympathetic damage. No diference was found in OCTT values between Child¿ A patients (52±17 minutes) and controls (52±13 min). In contrast, OCTT values were significantly higher in Child¿ B/C patients (71±34minutes) than in controls. Bacterial overgrowth occurred in only two patients. The mean follow-up time was 19±12 months. At the end of the study, five Child¿s B/C patients (24%) have died. The values of parameters representative of parasympathetic function (HF, lnHF) were significantly lower (p<0.05) in these patients in comparison with survivors of Child¿s B/C group. Hepatic encephalopathy was the most frequent complication during follow-up, occurring in 42.8% of Child¿s B/C patients. AD was significantly associated with encephalopathy (p<0.05), but did not correlate with OCTT values. In conclusion, our study showed that autonomic dysfunction in common in patients with non-alcoholic liver disease and is related to the severity of hepatic dysfunction. Our results did not show a relationship between delayed intestinal transit and AD. The presence of autonomic damage predisposes these patients to the development of encephalopathy and may be associated to higher mortality / Mestrado / Clinica Medica / Mestre em Clinica Medica