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Biomedical subjects

I Murray-Lyon

Publications and source records attributed to I Murray-Lyon.

11 recordsLinked to original sources

Ribavirin and interferon alfa-2b in chronic hepatitis C: assessment of possible pharmacokinetic and pharmacodynamic interactions.

AIMS: The primary objective of this study was to determine whether pharmacokinetic interactions occurred between interferon alpha-2b (IFN) and ribavirin in patients with chronic hepatitis C infections. Additionally this study assessed the single and multiple-dose pharmacokinetics of ribavirin and IFN, and compared the safety, tolerability and antiviral pharmacodynamics of IFN plus ribavirin compared with either drug alone. METHODS: In this open label parallel group study, patients with chronic hepatitis C were randomized to receive IFN 3 million IU thrice weekly s.c. alone, ribavirin 600 mg twice daily p.o. alone or both drugs in combination over 6 weeks. Single and multiple dose pharmacokinetics and indices of antiviral pharmacodynamics were assessed during weeks 1 and 6, along with safety assessments during the study. RESULTS: The range of mean ribavirin terminal phase half-lives after single doses was 44-49 h. Comparison of week 1 and week 6 AUC(0,12h) values showed accumulation in plasma of approximately 6-fold. The range of mean washout half-lives after week 6 was 274-298 h, reflecting release of ribavirin from deep compartment stores. The range of single and multiple dose IFN terminal phase half-lives was 5-7 h. IFN demonstrated an increase in bioavailability (approximately 2-fold) upon multiple dose administration. Ribavirin and IFN pharmacokinetic parameters for combined ribavirin and IFN were similar to those during monotherapy with either compound, although the power of this study to detect differences was low. Serum HCV-RNA titers and ALT concentrations were reduced by IFN alone, ribavirin alone reduced ALT concentrations only, and combined IFN plus ribavirin produced numerically greater falls in both measurements than either treatment alone. Serum concentrations of neopterin and activity of 2',5'-oligoadenylate synthetase (2'5'-OAS) were increased by IFN alone and in combination with ribavirin, whereas serum 2'5'-OAS activity was decreased and neopterin concentrations unaltered by ribavirin monotherapy. IFN and ribavirin monotherapy produced characteristic changes in safety laboratory tests (IFN--reductions in white cells, neutrophils and platelets; ribavirin--reduced haemoglobin) and characteristic adverse event profiles (IFN--headache, flu-like symptoms, fatigue, anorexia, nausea, myalgia, and insomnia; ribavirin--headache, fatigue, myalgia, and pruritus). There was no additive effect of combination therapy on safety laboratory tests or reported adverse events. All changes were fully reversible upon treatment cessation. CONCLUSIONS: There was no evidence of pharmacokinetic interactions between IFN and ribavirin in this study. There were numerical trends indicating that the combination of IFN and ribavirin reduced titers of HCV-RNA to a greater extent than did either treatment alone, and the safety profile of combination therapy was similar to those of both monotherapy treatments.

Adolescent↗

Neurology and the gastrointestinal system.

Both achalasia and Hirchsprung's disease arise from defects of innervation of the oesophagus and distal large bowel respectively. Their consequences are confined to disorders of motility in the relevant part of the gastrointestinal tract. Many neurogenic and primary muscle disorders are associated with abnormalities of gut motility. Stroke, even when unilateral, is commonly associated with dysphagia. Transcranial magnetoelectric stimulation has established that the pharyngeal phase of swallowing tends to receive its innervation principally from one hemisphere. In many neurological disorders, dysphagia is only one part of the clinical picture but in some--for example, the Chiari malformation--dysphagia may be the sole or major feature. Disturbances of small and large bowel motility, when seen in neurogenic disorders, are associated with autonomic neuropathy and are particularly common in diabetes mellitus. Primary muscle disorders can lead to dysphagia (for example, with polymyositis or oculopharyngeal dystrophy) or defects of large bowel motility (for example, with Duchenne's muscular dystrophy). Primary gut disorders particularly associated with neurological disease include pernicious anaemia, nicotinamide and thiamine deficiencies, selective vitamin E deficiency, and coeliac disease. Inflammatory bowel disease is associated with thromboembolic complications which may include the CNS, inflammatory muscle disease, and abnormalities on MRI of the brain of uncertain relevance. Whipple's disease is a rare condition which sometimes is largely or entirely confined to the CNS. In such cases, a particular neurological presentation can indicate the diagnosis.

Diagnosis, Differential↗

Management of chronic hepatitis C: clinical audit of biopsy based management algorithm.

OBJECTIVE: To assess the attendance, outcome, compliance with treatment, and response to interferon alfa in patients with chronic hepatitis C who attended during 1995 and were treated according to a biopsy based algorithm. DESIGN: Retrospective audit of all patients with chronic hepatitis C attending outpatient clinics over one year. SETTING: The liver unit at a London teaching hospital. SUBJECTS: 255 patients with chronic hepatitis C. MAIN OUTCOME MEASURES: Patient survival, attendance, and compliance with diagnostic and therapeutic regimens. Response to interferon alfa treatment, based on loss of viraemia three months after cessation of treatment. RESULTS: A large proportion of patients (39%) with newly diagnosed chronic hepatitis C infection do not want to undergo further investigation. Of those patients who do attend for further treatment, a large proportion with severe hepatic fibrosis (42%) do not want to undergo currently available treatment. The response rate to interferon (21%) in treated patients was similar to that previously reported in a trial setting. There was no significant difference in response rates in patients with or without severe fibrosis not amounting to cirrhosis. In patients with cirrhosis there was a high incidence of hepatocellular carcinoma (18%) over a follow up period of 20 months. CONCLUSION: Current strategies aimed at investigating and treating patients with chronic hepatitis C are not acceptable to a large proportion of patients. Many patients with cirrhosis related to hepatitis C infection develop hepatic neoplasms, and management strategies to deal with this problem are urgently required.

Adult↗

Psychological and psychophysiological characteristics in irritable bowel syndrome.

Psychiatric disorder is reported to occur in a large proportion of patients with irritable bowel syndrome (IBS) and psychological treatment methods have been advocated for this patient group. In a sample of 25 out-patients with intractable IBS, only four patients with psychiatric disorder were identified. The majority did not have elevated levels of anxiety or depression nor was there evidence of significant abnormal illness behaviour. Electrodermal activity did not show the extremes of responding and habituation associated with anxiety, depression or chronic pain. It is suggested that, when accurate diagnostic criteria are employed, a specific relationship between IBS and psychopathology is no longer evident.

Adult↗

Pre-S proteins in hepatitis B.

Two reactive sequences of the pre-S regions of hepatitis B surface antigen were synthesized chemically and used in micro-ELISAs for the assay of pre-S1 and pre-S2 antigens in serum from patients with acute and chronic hepatitis B. Pre-S1 antigen correlated well with the presence of HBV-DNA and was no longer detectable on cessation of viral replication, after natural recovery and after successful treatment with alpha-interferon. Pre-S2 proteins were also lost after treatment with alpha-interferon. The results show that the assay of pre-S1 and pre-S2 proteins in serum provides additional useful markers for assessing patients with acute and chronic hepatitis B infection and for monitoring the response to treatment with interferon.

Amino Acid Sequence↗

Mitozantrone as single agent therapy in hepatocellular carcinoma. A phase II study.

Thirty-five patients with hepatocellular carcinoma (HCC) have been treated with the Anthracenedione derivative, Mitozantrone. One complete and 5 partial responses were seen in 22 evaluable patients and in a further 4 patients tumour size remained static for lengths of time ranging from 13 to 42 weeks. Therapy was well tolerated. Bone marrow suppression was dose-limiting but easily managed by dose reduction. Other acute toxicity was rare, vomiting and hair loss being reported only once each. Cardiac 'events' occurred in 5 patients, 3 of whom had received high total cumulative doses of Mitozantrone. We conclude that Mitozantrone is of clinical benefit in HCC and that its usage is compatible with a good quality of survival. Its cardiotoxic potential requires further evaluation.

Adult↗

Lymphocyte cytotoxicity to autologous hepatocytes in HBsAg positive chronic liver disease.

Lymphocytes from 39 patients with HBsAg positive chronic liver disease were incubated with their own hepatocytes to investigate mechanisms of lymphocyte-mediated liver damage. Cytotoxicity was significantly increased in 46% overall, and in 73% of those with chronic active hepatitis. Unlike HBsAg negative chronic active hepatitis where only non-T cells were cytotoxic, HBsAg positive patients had both cytotoxic T and non-T cells. A purified liver membrane complex (LSP) and aggregated IgG both blocked non-T cytotoxicity without affecting T cell cytotoxicity; this suggests that the former is probably an antibody-dependent cell-mediated reaction against normal membrane components. This was confirmed in preliminary studies which demonstrated that preincubation of hepatocytes with the F(ab)2' fragment of an anti-human IgG reduced non-T lymphocyte cytotoxicity. T-cell cytotoxicity was restricted to HBeAg-positive patients, suggesting a relationship between T-cell cytotoxicity and viral replication. Purified HBsAg, however, blocked cytotoxicity in only three of 11 cases. Non-T lymphocytes reacting with normal membrane components may contribute to liver damage in both 'autoimmune' and virus-associated chronic liver disease, whereas cytotoxic T-cells, probably reacting with viral determinants, are exclusive to those with viral replication.

Adolescent↗