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Biomedical subjects

S Pol

Publications and source records attributed to S Pol.

At least 55 records · Page 3Linked to original sources
PubMed2000

HBV genotypic resistance to lamivudine in kidney recipients and hemodialyzed patients.

BACKGROUND: Lamivudine is a potent inhibitor of human immunodeficiency virus reverse transcriptase and hepatitis B virus (HBV) DNA polymerase. Its overall efficiency is clearly hampered by relapse at discontinuation and by risk of genotypic resistance. We describe herein the first cases of HBV resistance to lamivudine in kidney recipients and hemodialyzed patients. METHODS: We analyzed 26 HBV-infected kidney recipients and five hemodialyzed patients treated with lamivudine who became serum HBV DNA-negative (by Digene test). The biological and virological follow-up identified breakthrough as defined by the reappearance of serum HBV DNA. In two cases of breakthrough, HBV DNA was amplified and sequenced through the polymerase domain, including the YMDD motif, before the beginning of treatment and at time of breakthrough to determine genotypic mutations. RESULTS: Ten breakthroughs (reappearance of serum HBV DNA) were observed after a median follow-up of 11 months in eight kidney recipients and two hemodialyzed patients after a median duration of treatment of 16.5 (from 4 to 31) months of treatment. Previous HBe/anti-HBe seroconversion was not observed in the patients who escaped. In two kidney recipients, the comparison of HBV-DNA sequences before the treatment and after the breakthrough identified in one case a mutation of the highly conserved YMDD motif (YVDD), whereas in the second case, no genotypic mutation was observed in the sequenced region. CONCLUSION: We report the first cases of HBV genotypic resistance to lamivudine in kidney recipients and hemodialysis patients. Genotypic resistance is observed after 4-31 months of therapy. The YMDD mutation does not account for all cases of virological escape.

Adult↗
PubMed2000

[Clinical forms and prognosis of hepatitis C].

Hepatitis C virus infects around 600,000 French people, mainly after parenteral exposure (in association with transfusion before 1990 and with intravenous drug use). Spontaneous resolution at the acute stage of the infection occurs in around 30% of cases while chronic infection is observed in around 70% of cases and its main risk is evolution to cirrhosis. Three predictive factors of cirrhosis have been identified: the duration of infection (greater than 20 years), the age at contamination (greater than 40 years) and a chronic alcohol consumption (> 80 g/day). Immunosuppressive situations (drug-related immune suppression for the prevention of graft rejection in allograft recipients or human immune deficiency virus-coinfection) as well as hepatitis B virus coinfection enhance the risk of cirrhosis and reduce the time of occurrence of cirrhosis. These predictors have to be considered in the information to the patients and in therapeutic decisions. They explain that any hepatitis C virus-infected patient has to undergo a liver biopsy to evaluate the necro-inflammatory activity and the fibrosis of the liver disease to delineate the place of a follow-up with a control of aggravation factors (alcohol discontinuation) and of an antiviral therapy.

Adult↗
PubMed2000

Impact of TT virus infection in acute and chronic, viral- and non viral-related liver diseases.

BACKGROUND/AIMS: The prevalence and pathogenicity of TT virus, recently identified in patients with non A-non G post-transfusional hepatitis, are questioned. METHODS: We investigated the impact of this new viral infection in a large series of patients with non A-non G, cryptogenic, non-viral and viral-related, acute and chronic liver diseases (n=577) and blood donors (n=300). TTV DNA was detected in serum by hemi-nested polymerase chain reaction. Phylogenetic analysis was performed in 13 isolates. RESULTS: TTV DNA was detected in 6/25 and 15/127 patients with cryptogenic non A-non G acute and chronic liver disease, respectively. TTV DNA positive subjects with post-transfusional acute hepatitis scored negative before transfusion. TTV prevalence was increased in patients with cryptogenic non A-non G acute and chronic liver disease compared to blood donors (6/300; p<0.001) and non-viral-related chronic liver diseases (6/137; p<0.05). TTV/HBV coinfection was frequently identified (35/147), but this was not the case for HCV-infected subjects (4/77). Transaminase activity or liver histological score was not significantly increased among TTV positive, HBV infected or non A-non G patients. The HBV infection and Mediterranean origin were the risk factors associated with TTV infection. The majority of analysed sequences clustered in genotype 1 (8=1b; 3=1a). Two isolates showed homology to genotype 2. CONCLUSIONS: These results support the view that TTV is a widely spread infectious agent with a weak pathogenicity. It raises the possibility, however, that TTV might be implicated in a few cases of acute and chronic non A-non G hepatitis. TTV-DNA-analysed sequences are related to genotypes 1 and 2 described in Europe.

Acute Disease↗
PubMed2000

Combination of ribavirin and interferon-alfa surpasses high doses of interferon-alfa alone in patients with genotype-1b-related chronic hepatitis C.

The purpose of this study was to compare interferon-alfa alone (12-month course with high initial doses) with a combination of interferon-alfa and ribavirin in patients infected with genotype 1b. Three hundred and seven patients were randomized into 3 groups to receive 6 mega units (MU) of interferon-alfa-2b subcutaneously 3 times weekly for 6 months followed by 3 MU for 6 months (n = 95, group A); 10 MU for 3 months followed by 6 MU for 3 months, followed by 3 MU for 6 months (n = 83, group B); or the group-A schedule in combination with ribavirin (n = 129, group C) for 4 (n = 46), 6 (n = 44), or 12 months (n = 39). Negative polymerase chain reaction (PCR) was more frequent in group C than in groups A or B after 3 months of treatment (P <.006), at the end of treatment (P =.017), and at the end of follow-up (32.8%, 16.9%, and 14.1%, respectively, P <.003). A complete response (negative PCR and normal alanine transaminase) was higher in group C than in the other groups and when comparing 12- to 4- and 6-month combination therapy at the end of treatment (P =.05) and of follow-up (45.2% vs. 25.4%, respectively, P =.05). The greater efficacy of the combination was related to the higher rate of primary virological response and also to a decrease in the percentage of breakthrough and of relapse. In 1b-infected patients, the combination of high doses of interferon-alfa (6 MU) and ribavirin for 12 months appears to be the best therapy, with a high rate of sustained response.

Adult↗
PubMed2000

Abnormal reciprocal inhibition between antagonist muscles in Parkinson's disease.

Disynaptic Ia reciprocal inhibition acts, at the spinal level, by actively inhibiting antagonist motor neurons and reducing the inhibition of agonist motor neurons. The deactivation of this pathway in Parkinson's disease is still debated. Disynaptic reciprocal inhibition of H reflexes in the forearm flexor muscles was examined in 15 control subjects and 16 treated parkinsonian patients at rest and at the onset of a voluntary wrist flexion. Two patients were reassessed 18 h after withdrawal of antiparkinsonian medication. At rest, the level of Ia reciprocal inhibition between the wrist antagonist muscles was not significantly different between patients and controls. In contrast, clear abnormalities of this inhibition were revealed by voluntary movements in the patients. In normal subjects, at the onset of a wrist flexion, Ia reciprocal inhibition showed a large decrease, and we argue that this decrease is supraspinal in origin. On the less affected sides of the patients the descending modulation was still present but lower than in controls; on the more affected sides this modulation had vanished almost completely. These movement-induced abnormalities of disynaptic Ia reciprocal inhibition were closely associated with Parkinson's disease but were probably not dependent on L-dopa. They could play a role in the disturbances of precise voluntary movements observed in Parkinson's disease.

Adult↗
PubMed2000

Dilated bile duct in patients receiving narcotic substitution: an early report.

Narcotic substitution is now widely used. Morphine can induce a spasm of the sphincter of Oddi but dilation of bile duct has been reported only in an anecdotal case. In June 1995, we observed a first case of dilation of the common bile duct without organic obstacle in a hepatitis C virus (HCV)-infected patient who was under narcotic substitution, suggesting a causal relationship. We conducted a prospective study to evaluate the precise prevalence of bile duct abnormalities related to narcotic substitution in active intravenous drug or ex-intravenous drug users referred to our liver unit for histologic evaluation of HCV infection. We conducted a prospective study in a 30-month period of 334 HCV-infected patients, including 36 receiving narcotic substitution with methadone or buprenorphine. Biliary tract was analyzed by ultrasonography and by endoscopy ultrasound in cases of bile duct abnormalities. Of the 36 patients under narcotic substitution, 3 (8.3%) had asymptomatic dilated bile duct without organic obstacle--defined as a common bile duct > or =9 mm--compared to 1 of 298 (0.03%; p < 0.001) of those who did not receive substitution. Narcotic substitution may lead to bile duct dilation that does not require invasive diagnosis procedures.

Adult↗
PubMed2000

Safety and efficacy of interferon-ribavirin combination therapy in HCV-HIV coinfected subjects: an early report.

BACKGROUND: More severe liver disease together with a poor response rate to alpha interferon argue for the use of more potent anti-hepatitis C virus (HCV) therapies in human immunodeficiency virus (HIV)-HCV coinfected patients, but the efficacy and safety of interferon-ribavirin combination therapy in HIV infected subjects are unknown. AIM: To retrospectively evaluate the efficacy and safety of anti-HCV combination therapy in 21 HCV-HIV coinfected patients receiving antiretroviral therapy, and to access the clinical relevance of in vitro inhibition of phosphorylation by ribavirin of potent inhibitors of HIV-that is, zidovudine, stavudine, and zalcitabine. PATIENTS: Twenty one patients were treated with combined antiretroviral therapy including zidovudine (n=8) or stavudine (n=13) (in association with protease inhibitors in 12). All received ribavirin (1000 or 1200 mg/day) and alpha interferon (3 MU three times/week) for chronic hepatitis C infection. All patients had not responded (n=20) or relapsed (n=1) after a previous six month course of alpha interferon therapy. METHODS: HIV viral load (Monitor test) and CD4 cells count were measured at the beginning and every three months during and after ribavirin plus alpha interferon therapy over a mean period of 11 (1) months. Clinical and biological adverse effects were recorded. RESULTS: There was no significant variation in HIV viral load or CD4 cell counts after three or six months of ribavirin therapy compared with baseline values. Of the 21 subjects, three (14%) had an increase in HIV viral load of more than 0.5 log leading to discontinuation of ribavirin in one. Eleven of 21 (52.4%) had initial negative HCV viraemia at three (n=10) or six (n=1) months but only six were polymerase chain reaction negative at the end of therapy, leading to rates for primary response and breakthrough of 23.8% and 28.5%, respectively. Six months after completion of therapy, three patients relapsed (14. 3%) and three (14.3%) had sustained virological response. Median haemoglobin concentration decreased significantly after three and six months of ribavirin therapy (p= 0.0002 and p=0.0003, respectively) leading to withdrawal of therapy in one patient. CONCLUSIONS: These preliminary results show that: (1) despite in vitro interactions between ribavirin, zidovudine, and stavudine, significant variation in HIV replication does not usually occur in HCV-HIV coinfected patients receiving ribavirin and different antiretroviral regimens, including zidovudine and stavudine; (2) alpha interferon and ribavirin combination therapy induced primary and sustained virological responses in 28.5% and 14.3% of treated subjects (who were previous non-responders to interferon therapy), respectively; (3) anaemia is a frequent adverse event. Such results should be confirmed in larger prospective trials.

Adult↗
PubMed2000

[Treatment of viral hepatitis in drug addicts].

Management of viral hepatitis in drug uses must follow a multidisciplinary approach within the framework of overall psychosocial, alcohologic, and medical care. Substitution is an important but not indispensable aspect. In patients who have achieved social, psychological and medical stability (possible initiation of antiretroviral treatment), antiviral treatments can be started and followed in the same way as for other patients. Prescriptions should aim at improving the liver disease and avoid progression to cirrhosis and complications. Ribavirin/interferon-alfa appears to be the combination of choice for first line treatment of hepatitis C (while waiting for combinations with protease inhibitors). Anti-HBV vaccination is the treatment of choice for the prevention of hepatitis B and D. Coordination and information sharing between health and social care partners is crucial for the management of these patients.

Alcoholism↗
PubMed1999

Liver resection and needle liver biopsy cause hematogenous dissemination of liver cells.

We have investigated whether liver resection and needle liver biopsy cause dissemination of liver cells into peripheral blood circulation, using a reverse-transcription polymerase chain reaction (RT-PCR)-based assay targeted against alpha-fetoprotein (AFP) mRNA. Twelve patients with and 16 without primary liver cancer (PLC) undergoing liver resection were tested before skin incision, after liver mobilization, after hepatic parenchyma transection, after abdominal wall suture, and 4 days after surgery. Two patients with and 20 without PLC were tested before, 20 minutes after, and 24 hours after needle liver biopsy. Six of 14 patients with and 0 of 36 patients without PLC scored positive before intervention (P <.001). Liver cell spreading was induced at different times after surgery and liver biopsy in 14 of 14 patients with but also 23 of 36 without PLC (P <.05). We conclude that liver resection and needle liver biopsy induce release of cells from the liver, which are not necessarily liver tumor cells, into the peripheral blood circulation. This may be, however, an important mechanism of liver cancer cell dissemination deserving further investigations.

Adult↗
PubMed1999

Handedness-related asymmetry in transmission in a system of human cervical premotoneurones.

The possibility was investigated that human handedness is associated with an asymmetrical cortical and/or peripheral control of the cervical premotoneurones (PreMNs) that have been shown to mediate part of the descending command to motoneurones of forearm muscles. Heteronymous facilitation evoked in the ongoing voluntary extensor carpi radialis (ECR) electromyographic activity (EMG) by weak (0.8 times motor threshold) stimulation of the musculo-cutaneous (MC) nerve was assessed during tonic co-contraction of biceps and ECR. Suppression evoked by stimulation of a cutaneous nerve (superficial radial, SR) at 4 times perception threshold in both the voluntary EMG and in the motor evoked potential (MEP) elicited in ECR by transcranial magnetic stimulation (TMS) was investigated during isolated ECR contraction. Measurements were performed within time windows or at interstimulus intervals where peripheral and cortical inputs may interact at the level of PreMNs. Results obtained on both sides were compared in consistent right- and left-handers. MC-induced facilitation of the voluntary ECR EMG was significantly larger on the preferred side, whereas there was no asymmetry in the SR-evoked depression of the ongoing ECR EMG. In addition, the suppression of the ECR MEP by the same SR stimulation was more pronounced on the dominant side during unilateral, but not during bilateral, ECR contraction. It is argued that (1) asymmetry in MC-induced facilitation of the voluntary EMG reflects a greater efficiency of the peripheral heteronymous volley in facilitating PreMNs on the dominant side; (2) asymmetry in SR-induced suppression of the MEP during unilateral ECR contraction, which is not paralleled by a similar asymmetry of voluntary EMG suppression, reflects a higher excitability of cortical neurones controlling inhibitory spinal pathways to cervical PreMNs on the preferred side.

Adult↗
PubMed1999

Soluble tumor necrosis factor receptors in chronic hepatitis C: a correlation with histological fibrosis and activity.

BACKGROUND/AIMS: Tumor necrosis factor-alpha (TNF) is a mediator of inflammation and cellular immune response. Soluble TNF receptors (sTNFR) sTNF-R55 and sTNF-R75, which compete with cellular receptors for the binding of TNF, have been detected at high levels in infectious diseases including human immunodeficiency virus and HBV infection. In order to investigate the activation of the TNF system in HCV infection, we have analyzed the balance between TNF and sTNF-R in 60 HCV-infected subjects according to their clinical, biological, virological and histological characteristics. METHODS: Serum TNF, sTNF-R55 and sTNF-R75 levels were determined by ELISA before any therapy and were compared to a control group of 60 healthy subjects and a group of 34 HBV-infected patients. RESULTS: Mean TNF levels were 50.5+/-4.5 pg/ml in HCV patients, and undetectable (<5 pg/ml) in the control subjects. sTNF-R55 and sTNF-R75 levels were significantly higher in HCV-infected patients than in the controls: 2.88+/-0.14 ng/ml vs. 1.30+/-0.05, (p = 0.0001), and 9.54+/-0.58 ng/ml vs. 4.19+/-016, (p = 0.0001), respectively. sTNF-R55 and TNF-alpha levels in HCV patients were not significantly different from levels in HBV patients. sTNF-R75 levels were slightly lower than in HBV patients (9.54+/-0.58 vs. 11.4+/-0.79 ng/ml, p = 0.03). In contrast to other infectious diseases, there was no correlation between levels of sTNF-R and TNF. sTNF-R75 but not TNF levels were correlated with aminotransferases levels (p = 0.0001 and p = 0.0015 for aspartate and alanine aminotransferase, respectively), while sTNF-R55 levels were significantly correlated only with aspartate aminotransferase levels (p = 0.003). sTNF-R75 levels were significantly correlated with the Metavir activity index (p = 0.01), and sTNF-R55 and sTNF-R75 levels were significantly higher in patients with vs. without cirrhosis (3.22+/-0.21 vs. 2.54+/-0.17 ng/ml (p<0.02) and 11.6+/-0.86 vs. 7.5+/-0.53 ng/ml (p<0.001), respectively). sTNF-R55, sTNF-R75 and TNF levels were not correlated with viral load, genotype or response to interferon therapy. CONCLUSIONS: Levels of soluble TNF receptors, and particularly sTNF-R75, are significantly correlated with the severity of the disease but not with virological parameters such as quantitative viremia and genotype. High TNF-R production could thus suggest that HCV-related liver disease involves immunological mechanisms, including activation of the TNF system.

Adult↗
PubMed1999

A randomized trial of ribavirin and interferon-alpha vs. interferon-alpha alone in patients with chronic hepatitis C who were non-responders to a previous treatment. Multicenter Study Group under the coordination of the Necker Hospital, Paris, France.

BACKGROUND/AIM: Fifty percent of patients infected with hepatitis C virus (HCV) show no response to alpha-interferon, and no alternative therapy has thus far proven to be effective. Therapeutic combination with ribavirin and alpha-interferon has shown promising results in naive patients and in relapsers, but based on limited series, it was reported to be inefficient in non-responders. The aim of our study was therefore to explore and compare, in a randomized trial, the tolerance and potential efficacy of alpha-interferon alone with a sequential combination of ribavirin and the same alpha-interferon regimen in those patients. METHODS: Sixty-four non-responder patients were randomized in the alpha2b-interferon group (a 6-month course at a dosage of 6 MU followed by a 6-month course of 3 MU three times weekly subcutaneously) and 62 in the "combination" group (sequential combination of the same alpha2b-interferon therapy preceded by a 2-month course of ribavirin which was then associated for 2 months with alpha2b-interferon at a daily dosage of 1.0 or 1.2 g). RESULTS: Treatment withdrawal was necessary for six patients from the alpha-interferon and eight patients from the combination group. Normalization of aminotransferase activities was significantly more frequent after the 4-month course of ribavirin with 2 months of interferon than after 2 months of interferon alone (52.8 vs. 26.2%, p<0.01), but this difference was not maintained after ribavirin withdrawal. Disappearance of serum HCV RNA (PCR) was significantly more frequent at the end of treatment in the combination group (24.5 vs. 7.7%, p=0.02), but did not differ 6 months after the end of therapy (9.8 and 8.3%, respectively). The long-term response was not associated with liver status (cirrhosis vs. absence of cirrhosis) or genotype. Mean viremia was significantly lower in long-term responders than in non-responders or relapsers in both groups (p<0.001 for the interferon group and p<0.05 for the combination group), but the large extent of viral load precluded reliable prediction. The pre- and post-treatment hepatitis activity index did not differ between the two groups. While a crude histopathological improvement in the hepatitis activity index for a given patient was more frequently observed in the combination group (69.2 vs. 35.9%, p<0.01), improvement as defined by a decrease of at least 2 in the hepatitis activity index was significant only for lobular necrosis and degeneration. CONCLUSIONS: This study demonstrates the efficacy of the combination of ribavirin/alpha-interferon in non-responders. Indeed, (i) it is fairly tolerated; (ii) it increases the rate of the initial biological response, and of the virological response by decreasing breakthrough, though this benefit is not sustained; and (iii) it induces a significant histological improvement in necrosis. A simultaneous and prolonged combination of ribavirin/alpha-interferon should be further evaluated in non-responders.

Antiviral Agents↗
PubMed1999

Triggering of acute alcoholic hepatitis by alpha-interferon therapy.

BACKGROUND/AIMS: Alcohol may induce autoimmunity by recognition of acetaldehyde-modified proteins which may be implicated in the pathogenicity of acute alcoholic hepatitis. We report here the potential role of alpha-interferon, a potent inducer of the autoimmunity process, in inducing alcoholic hepatitis. METHODS: We analyzed clinical, biological, virological and histological features in two cases where alpha-interferon treatment for HCV-related hepatitis led to a marked increase in aminotransferase activities. RESULTS: alpha-interferon as treatment of HCV-related hepatitis seemed to exacerbate acute alcoholic hepatitis despite moderate alcohol consumption. In Case 1, moderate daily alcohol intake of 40 g during therapy led to biopsy-proven acute alcoholic hepatitis, while the same consumption before therapy did not. In Case 2, before treatment, the liver biopsy showed mild acute alcoholic hepatitis; aminotransferases increased during alpha-interferon therapy, although no increase in alcohol intake was observed. CONCLUSION: alpha-interferon therapy by its immunomodulatory properties could be implicated in alteration of the course of acute alcoholic hepatitis. These observations emphasize that the decision to treat with alpha-interferon when there is even moderate alcohol consumption should be carefully weighted in HCV-infected patients.

Acute Disease↗