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Biomedical subjects

C Trepo

Publications and source records attributed to C Trepo.

At least 163 records · Page 9Linked to original sources
PubMed1993

Histopathological assessment of tumoral destruction by alcoholization in an experimental model of human hepato-cellular carcinoma transplanted in nude mice.

This study aims to assess the efficacy of intra-tumoral alcoholization as a potential therapy against small hepatocellular carcinoma (HCC). The experimental model consisted of 20-mm diameter tumors resulting from subcutaneous abdominal injection of Hep G2 human hepatoma cell lines into nude mice (nu/nu). Alcoholization was performed using either a single centro-tumoral injection or multiple cross-shaped injections (tangential and oblique), during one sequence with a total dose of 0.1, 0.2 or 0.3 ml of 95% ethanol. Efficacy was assessed by the percentage of tumoral necrosis using a semi-quantitative method. Fifty-four tumors were alcoholized. Forty-eight hours following alcoholization, the tumor was regularly replaced by a necrotic ulcer. A single centro-tumoral injection always resulted in the persistence of a small peripheral edge of tumor cells even with the highest dose used (no dose-related effect). By contrast, the use of multiple injections restored a dose-related effect. Oblique cross-shaped injections of 0.3 ml of ethanol resulted in the highest mean tumoral necrosis rate (m +/- SD = 99 +/- 1%; range = 97-100). This study confirms that alcoholization is an efficient way to destroy hepatocarcinoma tissue and suggests that ethanol diffusion in HCC is less than 20 mm. In addition it demonstrates that increasing number and location of injections restores a dose-related effect, while efficacy is improved using oblique injections.

Animals↗
PubMed1993

Prevalence of intestinal protozoans in French patients infected with HIV.

To assess the prevalence of intestinal protozoans in French HIV-infected patients, stool samples, duodenojejunal biopsies, and/or colorectal biopsies from 81 patients were studied for parasites, viruses, and bacteria. Pathogens were found in 70.6% of AIDS patients with diarrhea or malabsorption. The respective prevalence of protozoa in AIDS patients with diarrhea was Cryptosporidium sp.: 37.3%, Blastocystis hominis: 13.7%, Giardia intestinalis: 5.8%, Isospora belli: 2%, Enterocytozoon bieneusi: 2%. Microsporidia were noted in one patient with severe malabsorption but no diarrhea. Other pathogens included cytomegalovirus in 27.4% and Mycobacterium avium in 5.8%. Patients with identified pathogens were more immunosuppressed and more severely malnourished than those with unexplained diarrhea. Multiple pathogens were found in 13 of 81 patients (16%). Twenty-six of 66 identified pathogens (40%) were diagnosed only on biopsy specimens. Chronic diarrhea in HIV patients could be explained in the vast majority by appropriate gastrointestinal investigations. Cryptosporidia played a major role, while microsporidia appeared to be less common.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Pulmonary hemorrhage and glomerulonephritis in primary biliary cirrhosis.

We observed life-threatening intrapulmonary hemorrhages and focal proliferative glomerulonephritis in a 41-yr-old woman with primary biliary cirrhosis. The severity of the symptoms necessitated blood transfusions and mechanical ventilation; the patient improved with the help of corticosteroid therapy. No formal evidence of either Goodpasture's syndrome or any other well-defined systemic vasculitis could be found. Neutrophil cytoplasmic antibodies were initially positive and became undetectable after 3 mo of immunosuppressive treatment without relapse. This association has not been described previously and may be added to the list of extrahepatic immune-mediated conditions associated with primary biliary cirrhosis.

Adult↗
PubMed1992

Phytohemagglutinin and concanavalin A activate hepatitis B virus in peripheral blood mononuclear cells of patients with chronic hepatitis B virus infection.

Peripheral blood mononuclear cells (PBMC) from 25 patients with chronic hepatitis B were tested for the presence of free monomeric hepatitis B virus (HBV) DNA migrating as a single 3.2 Kb band by Southern blot analysis. The PBMC were cultured for 7 days in the presence of phytohemagglutinin (PHA) or concanavalin A (ConA) both of which yielded a proliferative response. By contrast, both bacterial lipopolysaccharide (LPS) and interleukin 2 (IL2) failed to do so. Dot blot assays were used to monitor HBV DNA level increase within PBMC. Following mitogen exposure HBV DNA levels increased above pre-stimulation levels in 19/25 PHA cultures, 6/15 ConA cultures, 1/15 LPS cultures, and 1/15 IL2 cultures. In 15 patients, Southern blot analysis was carried out before and after PHA exposure. In 13/15 cases, a single 3.2 Kb band was observed in unstimulated cultures as well as in PHA cultures even though PHA induced a HBV DNA increase. One case exhibited bands migrating faster than the 3.2 Kb signal, compatible with replicating intermediates and one case provided evidence of viral concatemers within PBMC after PHA stimulation. No HBV DNA was detected in the culture supernatants. The increase of HBV DNA level in PBMC induced by mitogen was strongly associated with an increase in HBV DNA expression (HBV RNA and HBs antigen). These studies indicate that HBV DNA present in human PBMC does represent a potential reservoir for infection with endogenous reactivation following PBMC activation.

Blotting, Southern↗
PubMed1992

Should hepatitits-C virus antibody-positive donors be excluded from kidney donation?

In organ transplantation, virus transmitted by the donor is associated with a higher risk of severe primary infection after transplantation in the seronegative recipient. In this study, the risk of hepatitis-C virus (HCV) transmission by the kidney was determined, and the morbidity in the recipient assessed. Serum samples from all kidney donors of our Transplantation Unit between 1983 and 1988 were screened for antibodies to anti-HCV by first enzyme-linked immunosorbent assay (Ortho ELISA) and positive samples were confirmed by a second-generation ELISA and the CHIRON RIBA HCV test. Of the 164 kidney donors whose sera were available, five were positive (3%) and all of them were positive with the RIBA test. Liver function was normal in the five donors. Seven recipients received a renal transplant from the anti-HCV-positive donors. Two patients had a follow-up too short to draw any conclusions. Two patients remained anti-HCV-negative up to 36 and 48 months, respectively, but one of them had chronic hepatitis. One patient was anti-HCV-positive before transplantation and remained positive over the 4-year follow-up. The two last patients seroconverted and acute hepatitis occurred at 16 and 101 days after transplantation, respectively. In both cases, no peroperative or postoperative transfusion was given and no other cause of hepatitis could be determined. A cirrhotic evolution was observed within 15 and 36 months in both cases. Thus HCV can be transmitted by a kidney transplant and cadaveric donors positive for anti-HCV antibodies should be excluded from kidney donation.

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

Viral spliced RNA are produced, encapsidated and reverse transcribed during in vivo woodchuck hepatitis virus infection.

By the use of reverse transcription followed by polymerase chain reaction (RT-PCR), we have identified one shorter than full-length, pregenomic viral RNA species in liver samples of woodchucks chronically infected with the woodchuck hepatitis virus (WHV). The spliced WHV RNA of about 2.4 kb in length was cloned and partially sequenced. The splicing donor and acceptor sites of this novel RNA are located, respectively, 130 nucleotides downstream of the ATG initiation codon of the core gene and 21 nucleotides upstream of the initiation codon of the pre-S2 surface gene. The splicing event generates a new core-polymerase fusion protein and removes the terminal protein domain and the spacer region of the polymerase gene. A nucleotide probe specific for the splice junction was used following RT-PCR, to further confirm the existence of this spliced RNA in the liver of seven WHV-infected woodchucks. Deleted viral DNA molecules corresponding to the 2.4 kb spliced RNA were also detected in the liver and, to a lesser extent, in the serum of infected woodchucks, suggesting that this spliced RNA can be encapsidated and reverse-transcribed during the course of natural WHV infection.

Amino Acid Sequence↗
PubMed1992

[European Acute Transfusion Hepatitis Interferon Study (EATHIS)].

Since 1989, a prospective, multicentric and collaborative study, named European Acute Transfusion Hepatitis Interferon Study (EATHIS), involving 16 blood centres in France is coordinated by a task force in collaboration with the Viral Hepatitis and Recipients working groups of the French National Society of Blood Transfusion. A phase of recipient screening may be completed by a therapeutic interferon protocol. Among 1,476 transfused recipients receiving an average of 4.4 blood components, 1,011 were followed up at least four months. The incidence of non-A, non-B post-transfusion hepatitis (PTH) was varying from 0.1 to 6% at the different locations. Out of 15 hepatitis cases, 10 were diagnosed as post-transfusional. These preliminary data indicate a reduced incidence of PTH, with a mean of 1% for the period 1989-1991. It emphasises the importance of a transfusion vigilance program including follow up and testing for transaminases and specific viral markers.

Adolescent↗
PubMed1992

[Importance of PCR in the diagnosis of hepatitis C].

The identification of hepatitis C virus, based on DNA amplification, gives a precise estimation of the prevalence of the most frequent agent of NANB hepatitis. The first ELISA allowing the detection of anti-HCV antibodies, had too many false positive results and required the development of more sensitive and specific assays to confirm its results. PCR, allowing the hepatitis C virus diagnosis by showing directly HCV RNA sequences, offers a complementary approach to immunoserological tests. In blood donors with anti-HCV antibodies and with indeterminate or negative confirmatory tests, the finding of HCV RNA sequences reveals serum infectivity. During acute hepatitis, the delay in the appearance of anti HCV hampers acute phase diagnosis. The early detection of HCV RNA in peripheral blood, confirms the diagnosis and opens up therapeutic possibilities. In chronic hepatitis, the diagnosis of seronegative forms may only be resolved by PCR. Moreover, the presence of HCV RNA in peripheral blood represents the only marker of on-going viral replication and coincides with the severity of liver damage. During treatment with interferon, the follow up of HCV RNA sequences makes it possible to monitor its efficacy. The search for HCV RNA sequences directly in liver tissue shows that HCV may replicate in the liver in the absence of viremia. The presence of HCV RNA in the liver and the serum of liver transplanted patients is essential for the etiological diagnosis and management of hepatitis and bone marrow failure occurring after transplantation. Epidemiological study using PCR is a major tool in documenting vertical transmission between mother and child. Finally, PCR is important for the analysis of the HCV genome. Thus, in France there are at least three main strains, one close to the US prototype, the other close to the Japanese strain, possibly responsible for a more severe illness and a third one distinct from the previous two. However, its limits and constraints imply that PCR must not be considered as a routine assay. This emphasizes the need for more simple and rapid diagnostic tests, allowing the detection of HCV antigens and, as in hepatitis B, the progressive unravelling of the life cycle of HCV.

Animals↗
PubMed1992

Relevance of the quantitative detection of HIV proviral sequences in PBMC of infected individuals.

Changes in HIV replication during progression of HIV infection were assessed by estimation of the number of peripheral blood mononuclear cells (PBMC) harboring HIV proviral sequences. Samples from 23 patients at different stages of HIV infection were analyzed by quantitative polymerase chain reaction (PCR) using GAG primers. HIV titers in PBMC were also determined by serial dilutions of cells in coculture with phytohemagglutinin-activated normal PBMC. A positive correlation was observed between the number of HIV DNA copies and the HIV titer in PBMC. The PCR test was more sensitive than the coculture technique. The number of HIV copies detected by PCR ranged from 50 to 10,500 per 10(6) PBMC: assuming one copy per cell this implies a frequency of proviral HIV-containing cells of one per 100 to one per 20,000 mononuclear cells. The mean number of HIV DNA sequences in PBMC was significantly lower in asymptomatic patients than in AIDS patients and patients with AIDS-related complex (ARC). In patients who progressed from asymptomatic infection to AIDS, the number of HIV DNA copies in PBMC rose, indicating an increase of HIV replication. These results show that the number of infected PBMC increases during clinical progression. However, some asymptomatic patients had a higher number of HIV DNA copies in their PBMCs suggesting that increased HIV replication precedes the appearance of clinical symptoms.

DNA, Viral↗
PubMed1992

Demonstration of woodchuck hepatitis virus infection of peripheral blood mononuclear cells by flow cytometry and polymerase chain reaction.

Peripheral blood mononuclear cells (PBMCs) from 10 woodchuck hepatitis virus (WHV)-infected woodchucks were examined for the presence of WHV surface (WHs) and core (WHc) antigens (WHsAg and WHcAg) by cytofluorometry using fluorescein isothiocyanate-conjugated anti-WHs and anti-HBc-purified immunoglobulins from woodchuck and human sera. The presence of viral DNA and RNA was detected in the serum and PBMCs from the same blood samples by polymerase chain reaction (PCR) with two primer sets located in the S and C genes of the WHV genome. Seven animals were found positive for both WHsAg and WHcAg on the surface of PBMCs: four WHV-chronic carriers, two WHsAg-positive animals with acute WHV infection, and one woodchuck which was bled during the incubation phase of WHV infection and which became WHsAg-positive only 1 month later. Sixteen to 71% of the studied leukocyte population expressed WHsAg with a low density of expression whereas 7 to 72% expressed WHcAg with a high density of expression. Only two cases were positive for WHsAg without WHcAg on PBMCs, one WHV chronic carrier and one anti-WHs-positive animal. All woodchucks positive for WHcAg and/or WHsAg by cytofluorometry were positive also for WHV DNA and RNA in PBMCs by PCR. The tenth animal was found negative for both viral antigens as well as for WHV DNA and RNA in PBMCs despite the presence of persistent viral DNA in the serum as detected by PCR. Five healthy woodchucks devoid of WHV serological markers served as negative controls. These results obtained with a novel approach further confirm, in the woodchuck model, that a significant proportion of PBMCs are probably permissive for WHV replication. The possible immunopathogenic implications of the phenomenon are discussed.

Animals↗
PubMed1992

New assays for quantitative determination of viral markers in management of chronic hepatitis B virus infection.

We performed a quantitative study of serum hepatitis B virus (HBV) markers, including new parameters such as pre-S1 antigen (Ag), pre-S2 Ag, and anti-HBx, in 88 chronic hepatitis B surface antigen (HBsAg) carriers. New IMx assays for HBsAg and immunoglobulin M (IgM) anti-HBc detection were also used. The population studied was composed of 65 chronic hepatitis cases (40 positive for hepatitis B antigen [HBeAg] and 25 positive for anti-HBe) and 23 anti-HBe-positive, asymptomatic HBsAg carriers. Serum HBsAg levels detected by IMx were higher in HBeAg-positive than in anti-HBe-positive HBsAg carriers (all patient subgroups included) and correlated with the serum HBV DNA level (P = 0.0001). Both pre-S1 and pre-S2 Ags were detected by enzyme immunoassays in almost all HBsAg carriers. Both pre-S1 and pre-S2 Ag titers correlated positively with the serum HBsAg concentration (P = 0.0001), but only the pre-S1 Ag titer correlated with the level of serum HBV DNA (P = 0.02). The detection of low levels of IgM anti-hepatitis B core (anti-HBc) antibodies by IMx was associated with the presence of liver disease (P = 0.05) but not with the level of viral replication. The prevalence of anti-HBx antibodies detected by the enzyme immunoassay was slightly, although not significantly, higher in patients with high levels of HBV DNA (greater than 100 pg/ml) than in patients without detectable HBV DNA (P = 0.16). In anti-HBe-positive chronic HBsAg carriers, the quantitative detection of serum HBV DNA, pre-S Ag titers, and IgM anti HBc allowed us to predict which patients suffered from chronic liver disease and/or supported viral replication (P < 0.05). In a follow-up study of eight patients undergoing antiviral therapy, the clearance of both pre-S1 Ag and HBV DNA was associated with a subsequent clearance of HBV. Therefore, the quantitative determination of HBV DNA, pre-S Ags, IgM anti-HBc may prove useful for the decision to use and the monitoring of antiviral therapy, especially in anti-HBe-positive HBsAg carriers.

Carrier State↗
PubMed1992

[Rectal ganglioneuromatosis and multiple type IIb endocrine neoplasia].

Intestinal tract ganglioneuromatosis was discovered in a 27-year old man through surgical biopsy specimens obtained after acute intestinal obstruction. The patient then developed type IIb endocrine neoplasia including a marfanoid morphotype, mucosal neuromatosis, metastatic medullary carcinoma of the thyroid and bilateral pheochromocytoma. The histological and clinical features, the pathophysiological mechanisms of intestinal ganglioneuromatosis and its place within the intricate group of neurocristopathies are discussed.

Adrenal Gland Neoplasms↗
PubMed1992

Polyarteritis nodosa related to hepatitis B virus. A retrospective study of 66 patients.

In an attempt to establish the characteristics, circumstances leading to infection and development of polyarteritis nodosa (PN) related to hepatitis B virus (HBV), prognostic factors and outcome, and to define the most effective treatment, 66 patients observed between 1972 and 1989 were analyzed. Hepatitis was clinically present in 19/66 patients before PN. In most cases, PN occurred less than 6 months after infection. Clinical manifestations of PN were comparable to those observed in patients without HBV infection except for orchitis which was present in 13.6% and for pulmonary signs which were absent. Transaminases were normal in 38 cases for SGOT and 31 for SGPT and twice the normal range or more in the other cases. Antineutrophil cytoplasmic antibodies (ANCA) were tested in 22 patients and present in 2 (9%). Twenty-eight patients were treated with prednisone +/- oral cyclophosphamide +/- plasma exchanges. Thirty-eight patients were given a short-term treatment with prednisone followed by the association of vidarabine, 15 mg/kg bw/d for one week and 7.5 mg/kg bw/d for 2 weeks, and plasma exchanges: 14 sessions during the 3 weeks of vidarabine infusion, then tapered until stopping treatment after 2 to 3 months depending upon the clinical results obtained. The mean duration of follow-up was 50.3 +/- 46.1 months. At the end of follow-up, 13 of the 28 patients (46.4%) treated with steroids +/- cyclophosphamide +/- plasma exchanges died and 7/38 (18.4%) of those treated with vidarabine and plasma exchanges (p < 0.001) died. HBe/anti-HBe seroconversion was observed in 2 patients treated with prednisone +/- cyclophosphamide +/- plasma exchanges who were alive at the time of final analysis and in 16 patients receiving the other regimen. The outcome of patients treated with a few days of prednisone, vidarabine and plasma exchange was good and, therefore, we propose this protocol as the first viable treatment for polyarteritis nodosa related to HBV, surpassing the conventional treatment with steroids and cyclophosphamide, which stimulates viral replication.

Adult↗