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Biomedical subjects

P Berthelot

Publications and source records attributed to P Berthelot.

At least 19 recordsLinked to original sources
PubMed1992

Differing actions of beta-(2-thienyl)-gamma-aminobutyric acid in central and peripheral preparations.

In the guinea-pig isolated ileum, beta-(2-thienyl)-gamma-aminobutyric acid (BTG; 100-500 microM) reversibly and competitively (pA2 = 4.3 +/- 0.1) antagonised the baclofen-induced (5-100 microM) depression of cholinergic twitch contractions, but not that to adenosine or morphine. By contrast, in rat neocortical slice preparations, BTG (100-500 microM) acted as an agonist, abolishing the frequency and amplitude of spontaneous discharges, sensitive to 2-hydroxysaclofen (100-500 microM). BTG exhibits differential actions at GABAB receptors in brain and periphery.

Animals↗
PubMed1992

Actions of thienyl analogs of baclofen in the guinea-pig isolated ileum.

In guinea-pig isolated ileal preparations, the 5-methylthien-2-yl (5d), 5-bromothien-2-yl (5f) and 5-chlorothien-2-yl (5h) analogs of baclofen depressed twitch responses to field stimulation in a dose-dependent manner. These actions were reversibly and competitively antagonised by 2-hydroxysaclofen but not by naloxone, phentolamine, propranolol or theophylline. The relative potencies (EC50 values) were baclofen (10 microM) greater than 5h (40 microM) greater than 5d (80 microM) greater than 5f (120 microM). These analogs represent a novel class of specific GABAB receptor agonists which, like baclofen, should readily enter the brain.

Animals↗
PubMed1992

Interactions between human immunodeficiency virus-1, hepatitis delta virus and hepatitis B virus infections in 260 chronic carriers of hepatitis B virus.

To evaluate the factors determining the severity of chronic hepatitis B virus infection and the interactions of human immunodeficiency virus and hepatitis delta virus infections, we retrospectively analyzed 260 patients, 146 of whom were followed for a mean of 31.4 +/- 1.8 mo. Human immunodeficiency virus, hepatitis B virus, and hepatitis delta virus status and aminotransferase activities, histological activity index, alcohol consumption and the prevalence of cirrhosis were investigated. The patients included 54 homosexuals, 19 parenteral drug abusers and 187 subjects with other or unidentified risk factors for exposure to hepatitis B virus. Thirty-five patients (13%) were positive for antibody to human immunodeficiency virus; 27 were homosexual and 8 were drug abusers. The mean aminotransferase activities, histological activity index and the prevalence of cirrhosis were similar in the human immunodeficiency virus-positive and human immunodeficiency virus-negative subgroups. Actuarial survival was significantly lower in the human immunodeficiency virus-negative subgroups. Actuarial survival was significantly lower in the human immunodeficiency virus-positive group than in the human immunodeficiency virus-negative subjects (p = 0.004); the cause of death was clearly related to liver failure in four of the five human immunodeficiency virus-positive patients and two of the six human immunodeficiency virus-negative subjects who died. To evaluate the factors determining the severity of liver disease, we compared homogeneous subgroups of subjects. Among the homosexual patients, the prevalence of HBeAg and hepatitis B virus DNA, aminotransferase activities and the histological activity index did not differ according to human immunodeficiency virus antibody status.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1992

Enterocytozoon bieneusi infection in acquired immunodeficiency syndrome-related sclerosing cholangitis.

Acalculous cholecystitis and sclerosing cholangitis due to Cryptosporidium sp, and cytomegalovirus have been described in patients with the acquired immunodeficiency syndrome (AIDS). However, in about 40% of cases of AIDS-related biliary disease, no opportunistic pathogen is identified. The current case report describes the first case, to the best of the authors' knowledge, of AIDS-related sclerosing cholangitis associated with microsporidiosis. Enterocytozoon bieneusi was detected in the duodenum and bile by means of light microscopy and confirmed by electron microscopy. Microsporidian infection should be suspected in patients with AIDS-related sclerosing cholangitis as well as in cases of diarrhea in which none of the usual pathogens are found.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Chronic alcohol intoxication decreases the serum level of hepatitis B surface antigen in transgenic mice.

Hepatitis B virus (HBV) infections with an unusual serological profile, viz. positivity of HBV-DNA in the absence of hepatitis B surface antigen (HBsAg), have been described in alcoholics. This atypical pattern could be due to a low circulating level of viral particles rendering HBsAg undetectable with commercial kits, whereas HBV-DNA remains positive using the highly sensitive hybridization technique. We hypothesize that the well-known alcohol-induced impairment of protein secretion could also concern HBsAg particles and leads to a decrease in serum levels of the HBs antigen. To verify this hypothesis, we used HBsAg-positive transgenic mice as an animal model. Twelve HBsAg+ mice were separated into two groups; one group (n = 6) was submitted to increasing alcoholisation over an 18-week period, while the other (n = 6) was water fed. Seven HBsAg- littermates acted as controls: three received the alcohol regimen and the remaining four water. Chronic excessive alcoholisation lead to a significant decrease in serum HBsAg concentrations, while there was no obvious change in liver S mRNA. Ultrastructural studies showed a significant decrease in the number of microtubules in the livers of alcohol-fed mice. Finally, immunohistochemical studies performed at the end of the experiment showed a greater accumulation of HBsAg in the livers of HBsAg+ alcohol-fed (mainly located in the centrilobular area) than in the HBsAg+ water-fed mice. Our results (i) validate our initial hypothesis that chronic alcohol abuse leads to a decrease in serum HBsAg concentrations. This could explain, in part at least, the serological dissociations which were observed. (ii) Confirm the utility of screening serum HBV-DNA in alcoholics.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1992

Hepatitis C virus in kidney recipients. Epidemiology and impact on renal transplantation.

In an attempt to evaluate the prevalence, kinetics and impact of HCV infection in renal transplantation, we analyzed 140 kidney recipients according to the histopathological status of the liver. Thirty-three HBsAg-negative patients had chronic active hepatitis, 73 HBsAg-negative patients had a normal liver, 21 HBsAg-negative kidney recipients had minimal pathological changes and 13 patients had HBsAg-positive cirrhosis. Serum antibodies to HCV were detected using the ELISA from Ortho Diagnostic and confirmatory tests using the Ortho recombinant-based immunoblot assays. The overall prevalence of antiHCV antibodies was 23.6%. AntiHCV were more frequently present in HBsAg-negative patients with chronic active hepatitis (60.6%) than in HBsAg-negative patients with normal livers (8.2%) (p less than 0.0001) or minimal liver changes (33.3%) (NS) or in HBsAg-positive patients with cirrhosis (0%) (p less than 0.001). The recombinant-based immunoblot assays confirmed antiHCV-positive ELISA results in 86.7% of patients. Among the 27 antiHCV-positive kidney recipients who had serial serological follow-up, 10 (37.0%) were already positive at transplantation and remained antiHCV-positive during follow-up. Eleven patients (40.8%) acquired antiHCV an average of 95 months after renal transplantation, while antiHCV disappeared an average of 111 months after transplantation in six (22.2%), who had antiHCV prior to transplantation. The kinetics of antiHCV antibodies did not differ according to liver histology. Patient and graft survival were not different in antiHCV-positive and antiHCV-negative kidney recipients irrespective of liver histology, and there was no difference in survival between antiHCV-positive and antiHCV-negative patients with chronic hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Failure of acyclovir to enhance the antiviral effect of alpha lymphoblastoid interferon on HBe-seroconversion in chronic hepatitis B. A multi-centre randomized controlled trial.

Serum HBeAg levels and HBe-seroconversion were investigated in patients with chronic HBeAg-positive hepatitis who were randomized to receive either alpha lymphoblastoid interferon (5 megaunits subcutaneously daily for 16 weeks) plus acyclovir (2 g intravenously daily during weeks 1 and 2 and weeks 9 and 10) (n = 49) or no treatment (n = 48). HBeAg levels in serial dilutions of patient serum were assessed quantitatively by radioimmunoassay and compared with the values found for negative control serum. One year after the start of therapy 44 treated patients and 43 control patients were available for follow-up. A complete response (HBe-seroconversion) occurred in 11 treated patients (25%) and six controls (14%) (difference: 11%, 95% CI-5-28%). A partial response (HBeAg less than 50% of initial level) was found significantly more often for treated patients (n = 13, 30%) than for controls (n = 2, 5%) (difference: 25%, 95% CI 10-40%). During acyclovir-interferon combination therapy the decrease in HBeAg level was similar to that achieved during therapy with interferon alone. We conclude that acyclovir does not enhance the effect of interferon on serum HBeAg levels. Since HBeAg levels continue to decline during interferon treatment and rebound thereafter to pretreatment levels, prolongation of therapy may yield a higher response rate.

Acyclovir↗
PubMed1992

Hepatitis C viremia and anti-HCV antibodies in alcoholics.

We determined serum hepatitis C status using a RIBA2 kit and a sensitive PCR procedure in 62 chronic alcoholics, 36 of whom had anti-HCV antibodies (Ab) detectable in an ELISA1 assay. Anti-HCV antibodies were detected in 22 patients using RIBA2. HCV RNA was detected by means of PCR in 18 patients who were RIBA2 positive and in none who were RIBA2 negative. Liver biopsies, available for 12 HCV RNA-positive patients, revealed histological features of purely alcohol-related lesions in seven and mixed alcohol-viral lesions in five. These results indicate that HCV replication is maintained in most alcoholics who score positive for anti-HCV Ab in the RIBA2 test, and that HCV viremia can be associated with histological features typical of alcoholic liver disease.

Adult↗
PubMed1992

Serum hepatitis C virus RNA and hepatitis B virus DNA in non-A, non-B post-transfusional and sporadic chronic hepatitis.

The sera of 36 French patients with post-transfusional and sporadic non-A, non-B chronic hepatitis were investigated, for HBV and HCV infections using a combination of serological and polymerase chain reaction (PCR) assays. Anti-HCV was detected in 75% (27/36) of the patients by ELISA1 and/or RIBA2 tests. HCV-RNA sequences were found in 75% (27/36) of the sera by a single step PCR, using a set of primers located in the 5' non-coding region. Altogether, 89% (32/36) of the patients were found positive with serological and/or molecular tests. Among the positive patients, 68% (22/32) were found positive for both anti-HCV and HCV-RNA, 16% (5/32) and 16% (5/32) were found positive for either anti-HCV or HCV-RNA, respectively. HBV-DNA sequences were detected in two patients associated to the HCV viraemia. This study confirms the extremely high prevalence of HCV infection in NANB chronic hepatitis in France. It also shows possible co-infection by HCV and HBV in hepatitis.

Base Sequence↗
PubMed1992

Absence of hepatitis delta virus infection in chronic hemodialysis and kidney transplant patients in france.

Hemodialyzed patients and kidney recipients are frequently multiply-transfused and infected by hepatitis B virus (HBV). Hepatitis delta virus (HDV) has a symbiotic association with HBV. The prevalence of HDV infection has, surprisingly, not been assessed in patients in hemodialysis or renal transplantation setting. We retrospectively studied the prevalence of serum delta antigen and antidelta antibodies by a microenzyme-linked immunosorbent assay in 77 of the 80 HBsAg-positive patients who underwent a kidney transplantation over a 10-year period. Of these patients, 73% had active HBV replication as assessed by the presence of serum HBV DNA and 65% had a biopsy-proved chronic active hepatitis, including cirrhosis. None of our patients had any marker of HDV infection at the end of the hemodialysis period or at the end of follow-up in transplantation. These results establish that HDV superinfection has indeed been extremely rare during end-stage renal failure and kidney transplantation in France, in contrast to HBV reactivation or hepatitis C virus infection.

DNA, Viral↗
PubMed1991

[Hepatitis C in kidney recipients. Epidemiology and impact on kidney transplantation].

In an attempt to evaluate the prevalence, the kinetics and the impact of HCV infection in renal transplantation, we analyzed 140 kidney recipients according to hepatic histology: 33 HBsAg negative patients had chronic active hepatitis, 73 HBsAg negative patients had a normal liver, 21 HBsAg negative kidney recipients had minimal pathological changes and 13 patients had HBsAg positive cirrhosis. Serum antibodies to HCV were detected using the ELISA test. The overall prevalence of anti-HCV antibodies was 24.3 percent: anti-HCV were more frequently present in HBsAg negative patients with chronic active hepatitis (57.5 percent) than in HBsAg negative patients with normal liver (8.2 percent) (P less than 0.0001) or minimal changes (33.3 percent, NS) and HBsAg positive patients with cirrhosis (15.4 percent) (P = 0.02). Among the 30 anti-HCV positive kidney recipients with serological follow up, 13 (43.3 percent) had anti-HCV antibodies at the time of transplantation and kept anti-HCV during follow up, 11 (36.7 percent) acquired anti-HCV after renal transplantation in a mean time-lag of 95 months while 6 (20 percent), who had anti-HCV prior to transplantation, exhibited negativation of anti-HCV antibodies in a mean time-lag of 111 months after transplantation. The kinetics of anti-HCV antibodies was the same irrespective of the liver status. Patients and grafts survivals were not different in anti-HCV positive and anti-HCV negative kidney recipients, whatever the hepatic histology. Our data suggest that, in kidney transplantation, a) the prevalence of anti-HCV antibodies is around 24 percent in kidney recipients and varies greatly according to hepatic histology; b) anti-HCV antibodies are not systematically associated with the development of chronic liver disease; c) post-transfusion hepatitis as well as so called community acquired hepatitis may occur in transplantation follow up; d) HCV infection does not clearly influence the survival of allograft or that of kidney recipients.

Adult↗
PubMed1991

Association between HCV and HBV infection in hepatocellular carcinoma and alcoholic liver disease.

We conducted a retrospective study in 229 patients to determine the prevalence of hepatitis C virus (HCV) according to the type of liver disease and also the serum hepatitis B virus (HBV) status. There were 55 cases of hepatocellular carcinoma (HCC), 78 cases of alcoholic cirrhosis (AC) and 96 cases of non-cirrhotic alcohol liver disease (NCA). Half the AC and NCA groups were constituted of patients with or without serum HBV markers. The prevalence of anti-HCV antibodies in HCC (58.2%) was significantly higher than in the other groups (AC, 35.9%; NCA, 17.7%). Combining the two AC and NCA groups gave a 25.8% anti-HCV prevalence in the alcoholics. Altogether anti-HCV antibodies were more frequently present in HBV-positive than in HBV-negative patients (42.2 vs. 26.1%, p less than 0.01), although the difference was not significant when the HCC group was separately analysed. The S/N ratio of anti-HCV-positive samples varied according to the type of the disease (tumorous vs. non-tumorous) and to the serum HBV status. Indeed, 65.6% of HCC had a S/N greater than 4 compared to only 32.2 and 23.5% in AC and NCA, respectively (p less than 0.01). On the other hand more than half of the AC and NCA had a S/N less than 2, indicating possible artefacts in certain cases. The 15 HBsAg and anti-HCV-positive patients had a significantly lower mean S/N than patients displaying only antibodies against HBV, even in the HCC group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Hepatic activity and mRNA expression of aspartate aminotransferase isoenzymes in alcoholic and nonalcoholic liver disease.

In liver and serum, AST activity is dependent on two isoenzymes, which are mitochondrial and cytosolic in nature. In an attempt to explain the well-known increase of serum mitochondrial AST-to-total AST ratio in chronic alcoholism (which is due to a specific increase of the mitochondrial isoenzyme), we analyzed: (a) liver and serum AST, ALT and glutamate dehydrogenase activities in 23 active drinkers with minimal liver changes, 11 alcoholic patients with cirrhosis who had stopped drinking, 18 nonalcoholic patients with viral chronic hepatitis and 11 subjects with normal livers; and (b) the expression of messenger RNAs for AST isoenzymes in the corresponding liver samples. Enzymatic activities were decreased in the liver irrespective of the origin of the liver disease. In patients with viral chronic hepatitis (or in those with alcoholic cirrhosis when abstinent), variations in liver proteins and messenger RNAs paralleled significant decreases in mitochondrial AST, ALT and glutamate dehydrogenase and a nonsignificant decrease of cytosolic AST. In alcoholic patients with minimal liver changes, the significant decrease of hepatic cytosolic AST, ALT and glutamate dehydrogenase activities contrasted with a close-to-normal liver mitochondrial AST activity; the increased amounts of mitochondrial AST messenger RNA give evidence for a pretranslational mechanism of regulation, indicating a possible increase in the total production of mitochondrial AST in the liver. The decrease of hepatic cytosolic AST activity was statistically significant only in alcoholic patients without cirrhosis who had a normal cytosolic AST mRNA level, thus suggesting a contributory role of translational or posttranslational regulation. In conclusion, regulation of AST isozymes during liver disease is complex, including differential, pretranslational and translational or posttranslational mechanisms.

Aspartate Aminotransferases↗
PubMed1991

3-Thienyl- and 3-furylaminobutyric acids. Synthesis and binding GABAB receptor studies.

Baclofen (beta-(p-chlorophenyl)-GABA) is a selective agonist for the bicuculline-insensitive GABAB receptor. The search for new compounds that bind to the GABAB receptor is very important to clarify structural requirements. We report herein the synthesis and the binding studies of variously substituted 3-thienyl- and 3-furylaminobutyric acids. 4-Amino-3-(5-methyl-2-thienyl)butyric acid (5d) and 4-amino-3-(5-chloro-2-thienyl)butyric acid (5h) are potent and specific ligands for GABAB receptor. The IC50 values for the displacement of (R)-(-)-[3H]baclofen are 1.34 and 0.61 microM for 5d and 5h, respectively, as compared to 0.33 microM for baclofen.

Animals↗