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Biomedical subjects

F Morinet

Publications and source records attributed to F Morinet.

At least 55 records · Page 3Linked to original sources
PubMed1993

Detection of human T lymphotropic virus type I tax gene in salivary gland epithelium from two patients with Sjögren's syndrome.

OBJECTIVE: To investigate whether human T lymphotropic virus type I (HTLV-I) could be involved in the pathogenesis of Sjögren's syndrome (SS). METHODS: Labial salivary gland (LSG) biopsy specimens from 9 patients with SS (4 with primary SS and 5 with SS secondary to rheumatoid arthritis) and 9 controls were studied for the presence of the tax gene of HTLV-I using in situ hybridization, and for the presence of tax, gag, pol, and env genes of HTLV-I using the polymerase chain reaction (PCR). Testing for antibodies to HTLV-I and examination of lymphocytes on blood smears were performed to determine whether systemic viral infection was present. RESULTS: Using in situ hybridization and PCR, we detected the tax gene, but not the gag, pol, or env genes, of HTLV-I in LSG sections from 2 of 9 patients with SS and from none of the control subjects. Tax DNA was present mostly in nuclei of epithelial cells, but also in some lymphoid cells. Serum of the 2 affected patients did not contain antibodies to HTLV-I. In 1 patient, examination of blood smears revealed rare convoluted lymphocytes, sometimes with the appearance of "flower cells," as observed in the blood of HTLV-I-infected patients. CONCLUSION: None of the known endogenous retroviral sequences is homologous to the tax gene. Thus, we suggest that HTLV-I (or another related retrovirus) can infect salivary epithelium. Transactivation properties of the tax protein could be implicated in the pathogenesis of SS. Alternatively, viral infection could cause de novo expression of HLA-DR antigens and favor the presentation of antigens by epithelial cells, leading, in some genetically predetermined subjects, to lymphoid infiltration of the gland.

Antibodies, Viral↗
PubMed1993

Rapid detection of cytomegalovirus strains resistant to ganciclovir through mutations within the gene UL97.

The human cytomegalovirus (HCMV) gene UL97 product was shown to play an important role in phosphorylation of ganciclovir (GCV) in HCMV-infected cells. The deletion of the 4 amino-acid sequence AACR confers resistance to a laboratory mutant. The aim of this study was to develop a rapid and simple method to detect mutations within the 12 base pair (bp) fragment encoding AACR, from isolates and clinical specimens (urine, bronchoalveolar lavage, cerebral spinal fluid samples). A target region encompassing this 12bp sequence was amplified by a single-step PCR assay from HCMV isolates and reference strains, and a two-step procedure from clinical specimens. Reaction products were submitted to restriction enzyme analysis and dot-blot hybridization assay. Two biotinylated probes were used: one probe (DL) overlapping the 12bp region; and a control probe with similar length and GC content. Hybridization was performed under conditions allowing the detection of one bp deletion (HCMV strain susceptibility to GCV was determined by a rapid late antigen synthesis reduction assay.) The control probe hybridized to the UL97 sequence amplified from all 23 tested isolates and the reference strains. The DL probe gave a positive signal with GCV-susceptible strains; no signal was obtained for five out of seven resistant isolates, and for a laboratory mutant derived from the strain AD169. Restriction analysis of amplification products showed different patterns suggesting this region can be involved in various DNA changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1993

Diamond Blackfan anaemia: apparent relapse due to B19 parvovirus.

A spontaneous remission occurred after 3 years of regular transfusions in a cortico resistant Diamond Blackfan anaemia. However after 1 year of transfusion independence an apparent relapse was observed which was transient and could be attributed to a B19 parvovirus primary infection. Previous inapparent impairment of erythropoiesis can be transiently spotlighted by B19 parvovirus primary infection.

Antibodies, Viral↗
PubMed1993

Primary T-cell malignant lymphoma of the central nervous system. Histological, immunohistochemical and ultrastructural study of a case.

Most primary malignant lymphomas (ML) of the central nervous system (CNS) are derived from B-cells, whereas T-malignant lymphomas (T-ML) primarily arising in the CNS are extremely rare. We report on a patient with a primary T-ML of the CNS localised in the posterior fossa. On the basis of histological, ultrastructural and immunohistochemical studies, this tumour was classified as a pleomorphic T-ML, medium and large cell type with peripheral helper/inducer T-cell phenotype (CD 1-, CD 2+, CD 3+, CD 5+, CD 7-, CD 4+, CD 8-, CD 19-, CD 22-, UCHL 1+/CD 45 RO, L 26-/CD 20, LN 1-/CDW75, LN 2-/CD 74, MB 2-). Furthermore, the positivity of the markers CD 25 and HLA-DR on many medium-sized and large lymphoma cells suggests activation of these cells. The nuclear marker of proliferative activity Ki-67 was expressed in some large cells, whereas the natural killer cell-related markers CD 16 and Leu 7/CD 57 did not react with lymphoma cells. This study emphasises the value of extensive immunohistochemical investigations on frozen and paraffin sections in order to identify and characterize the T-cell malignancies, particularly in their rare CNS location.

Antigens, CD↗
PubMed1993

Trans-activation of the long terminal repeat of human immunodeficiency virus type 1 by the parvovirus B19 NS1 gene product.

Persistent parvovirus B19 infections in human immunodeficiency virus type 1 (HIV-1)-infected patients have been reported. The two viruses could share common target cells. The NS1 protein of B19 regulates B19 expression and we have investigated its possible effect on the long terminal repeat (LTR) of HIV-1. In transient transfection experiments, NS1 trans-activated the expression of reporter genes under the control of the HIV-1 LTR. The effect of NS1 was apparent only in the presence of the HIV-1 Tat protein, and required intact TAR and TATA box sequences.

Cell Line↗
PubMed1993

B19 parvovirus and blood transfusion.

B19 parvovirus, a non-enveloped DNA virus about 20 nm diameter, is responsible for benign illness in children (fifth disease) or in adult (arthritis). Nevertheless some acute or chronic anaemia may occur following the lysis of its target cell, the erythroid progenitors. Such clinical manifestations may be observed in blood transfused patients under circumstances which will be studied.

Acute Disease↗
PubMed1992

[Polymerase chain reaction (PCR) in microbiology. Value and practical applications].

The gene amplification reaction (PCR) developed in 1985 is a molecular biology instrument which is used to amplify genomic restriction fragment lengths of micro-organisms found in biological samples. At the moment, its applications to direct microbiological diagnosis remain to be determined precisely, and its strict technique is awaiting standardization. However, it is a powerful tool for molecular typing used to follow up an antiviral therapy or to analyse retrospectively paraffin-embedded tissue banks in search of viral or bacterial nucleic acids.

Bacterial Infections↗
PubMed1992

Multicentre quality control of polymerase chain reaction for detection of HIV DNA.

OBJECTIVE: Seven French laboratories tested the specificity and sensitivity of the polymerase chain reaction (PCR) for the detection of HIV-1 DNA. METHODS: Following its own PCR protocols, each laboratory independently tested blind two panels of 20 coded peripheral blood mononuclear cell samples collected from HIV-1-seropositive individuals and from HIV-1-seronegative individuals at high or low risk of HIV infection. For the first panel, laboratories were free to select type and number of primers; for the second, all were required to use the two primer pairs Pol 3/4 and MMy 9/10' (Nef 1). RESULTS: False-positive and false-negative results were observed in all laboratories (concordance with serology ranged from 40 to 100%). In addition, the number of positive PCR results did not differ significantly between high- and low-risk seronegatives. The use of crude cell lysates in DNA preparation produced the same PCR results as phenol-extracted DNA. Discrepancies between laboratories indicated that factors other than primer pairs contributed strongly to laboratory variability. CONCLUSIONS: Our results emphasize the importance of both positive and negative controls in PCR and demonstrate the value of multicentre PCR quality control.

Base Sequence↗
PubMed1992

[Fetal erythropoiesis and parvovirus B19].

Target cells for the human parvovirus B19 include erythroid progenitors located in the bone marrow in adults and in the liver in fetuses of 12 to 30 weeks gestational age. The main manifestations of fetal parvovirus B19 infection seem to be related to lysis of the erythroid progenitors which causes non immune hydrops fetalis with severe anemia, congestive heart failure, generalized edema and death. The exact incidence of human parvovirus B19 infection during pregnancy remains unclear.

Anemia↗
PubMed1991

Anti-B-cell monoclonal antibodies in the treatment of severe B-cell lymphoproliferative syndrome following bone marrow and organ transplantation.

BACKGROUND: The B-cell lymphoproliferative syndrome is an infrequent life-threatening complication of marrow or organ transplantation that is the consequence of profound immunosuppression. The results of treatment have been disappointing, although a small number of patients have been cured by chemoradiotherapy or antiviral agents after a reduction in the dosage of immunosuppressive therapy. We report here the results of treating this disorder with anti-B-cell antibodies. METHODS: Twenty-six patients in whom aggressive B-cell lymphoproliferative syndrome developed after bone marrow (n = 14) or organ (n = 12) transplantation received 0.2 mg of CD21-specific and of CD24-specific antibodies per kilogram of body weight for 10 consecutive days in an open, prospective, multicenter trial. RESULTS: The treatment was well tolerated. All patients had transient neutropenia, apparently because the CD24 molecule is also expressed on granulocytes. The treatment was ineffective in seven patients with monoclonal B-cell proliferation. In contrast, 16 patients with oligoclonal B-cell proliferation had complete remission. Systemic remission also occurred in two other patients with oligoclonal proliferation who had central nervous system involvement, although they subsequently died because of progression of the central nervous system disease. In one patient who died early, clonality was not determined. Of the 16 patients who had complete remission, 2 with persistent immunodeficiency due to graft (marrow) rejection or acute graft-versus-host disease had a relapse, and the 1 with graft-versus-host disease subsequently died. Eleven patients were alive and disease-free after a median follow-up of 35 months (5 of 14 marrow recipients and 6 of 12 organ recipients). Four other patients in complete remission died of unrelated causes 4 to 12 months after treatment. CONCLUSIONS: Intravenous administration of anti-B-cell antibodies may be effective in controlling diffuse, severe, oligoclonal B-cell proliferation not involving the central nervous system.

Adolescent↗
PubMed1991

[Virologic diagnosis of papillomavirus infections].

Human papillomavirus are strictly epitheliotropic and host-specific. Currently, 57 different types based on deoxyribonucleic acid sequence rather than serology have been identified. Some papillomavirus types infect the skin, while others infect the oral or genital mucous membranes. Human Papillomavirus type 16 is often associated with invasive carcinomas of the uterine cervix and of their intra-epithelial precursors. Recent data on viral pathogenesis suggest that the protein encoded by the E7 gene of human papillomavirus type 16 is able to bind to the retinoblastoma and p53 gene products. If various techniques for the detection of human papillomavirus may be used (cytology, electron microscopy and immunocytochemistry), as will become apparent, nucleic acid hybridization is the most reliable method for viral diagnosis and genotyping.

Humans↗