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Biomedical subjects

B Plouvier

Publications and source records attributed to B Plouvier.

At least 19 recordsLinked to original sources
PubMed1992

Productive human immunodeficiency virus-1 infection of megakaryocytic cells is enhanced by tumor necrosis factor-alpha.

Recent findings have indicated that megakaryocytes may be susceptible to human immunodeficiency virus (HIV) infection, suggesting a potential role for megakaryocytes as viral reservoirs in HIV-infected patients. We report that the megakaryocytic cell line Dami could be productively infected with the HTLV III-B strain of HIV-1, in 26 different experiments (results of 16 experiments are reported); productive infection lasted up to 30 weeks. Despite a lack of detectable surface expression of the CD4 molecule and very low levels of CD4 mRNA, between 40% and 60% of megakaryocytic cells produced viral proteins after contact with HIV-1. Neither cytopathogenic effects nor syncytial formation was observed. Production of high levels of functional viral particles was indicated by analysis of p24 protein levels, reverse transcriptase activity, ultrastructural studies, and the capacity of supernatants from infected Dami cells to infect the Molt-4 T-lymphocytic cell line. HIV-1 RNA and protein levels in infected Dami cells were enhanced by treatment with tumor necrosis factor-alpha (TNF-alpha), and decreased by treatment with interferon-alpha (IFN-alpha) and IFN-gamma. Transient transfection of the megakaryocytic cells with various constructs of the HIV-1 promoter (LTR) linked to the luciferase reporter gene suggested that the effect of TNF-alpha was related, as in monocytic and T-cell lines, to transactivation of the enhancer region of the HIV-1 LTR. These findings indicate that signals provided by the immune system may modulate HIV-1 expression in cells of the megakaryocytic lineage.

Cell Line↗
PubMed1991

DNA-sequence specific recognition by a thiazole analogue of netropsin: a comparative footprinting study.

Four different footprinting techniques have been used to probe the DNA sequence selectivity of Thia-Net, a bis-cationic analogue of the minor groove binder netropsin in which the N-methylpyrrole moieties are replaced by thiazole groups. In Thia-Net the ring nitrogen atoms are directed into the minor groove where they could accept hydrogen bonds from the exocyclic 2-amino group of guanine. Three nucleases (DNAase I, DNAase II, and micrococcal nuclease) were employed to detect binding sites on the 160bp tyr T fragment obtained from plasmid pKM delta-98, and further experiments were performed with 117mer and 253mer fragments cut out of the plasmid pBS. MPE.Fe(II) was used to footprint binding sites on an EcoRI/HindIII fragment from pBR322. Thia-Net binds to sites in the minor groove containing 4 or 5 base pairs which are predominantly composed of alternating A and T residues, but with significant acceptance of intrusive GC base pairs. Unlike the parent antibiotic netropsin, Thia-Net discriminates against homooligomeric runs of A and T. The evident preference of Thia-Net for AT-rich sites, despite its containing thiazole nitrogens capable of accepting GC sites by hydrogen bonding, supports the view that the biscationic nature of the ligand imposes a bias due to the electrostatic potential differences in the receptor which favour the ligand reading alternating AT sequences.

Base Sequence↗
PubMed1988

[Subacute extradural hematoma of the vertex. A case].

A patient suffers from a spasmodic triparesis 8 days after a cranial traumatism of the vertex. Ruptured superior sinus leads to development of an subacute extradural hematoma. The following course is uneventful after surgical cure. The localization, subacute evolution and clinical findings are rarely described in the literature.

Hematoma, Epidural, Cranial↗
PubMed1987

[Immunology and pregnancy].

Immunology in pregnancy is a meeting ground between basic research in biology and daily medical practice. For gynecologists and obstetricians, the authors have attempted to synthesize the acquired knowledge and the current hypotheses on this very complex topic. Three main chapters will be successively approached: a reminder of the normal immune system and its development in the fetus, immunity in pregnant women and the dysimmune pathology during pregnancy, the feto-maternal immune relationship and its possible complications.

Antibody Formation↗
PubMed1979

[Repeated abortions, sterility and systemic dysimmunopathy (author's transl)].

A patient with lupus disease had a previous medical history of five recurrent temporary bouts of thrombopenia which were followed by spontaneous abortions. This raises the two-fold problem of the relationship between circulating immune complexes disease and thrombopenia, and dysimmunopathy and pregnancy disorders. The hypothesis is raised of a trophoblastic necrotizing angeitis due to abnormal immunity processes involved in some cases of sterility, spontaneous abortions, and even nephropathies during pregnancy.

Abortion, Habitual↗
PubMed1979

[Paravertebral hematopoietic pseudotumor during Paget's disease (author's transl)].

Extramedullary hematopoiesis is usually secondary to a severe and prolonged reduction in medullary functions, but can be the rare consequence of an extrusion of tissue formed of weakened or fractured bone. The hematopoietic nature of this pseudotumor can be confirmed histologically or, as in this case of Paget's disease, by Indium scintigraphy which can define the specific locations of the hematopoietic marrow.

Aged↗
PubMed1979

[Systemic allergic vasculopathy after naproxen (author's transl)].

The authors report a case of hypersensitivity angiitis presenting with cutaneous, muscular, articular, and renal signs. They suggest a possible etiological mechanism for such disorders: a circulating immune-complex disease, and criticize the often improper interpretation of the results of lymphoblast transformation tests. Hypersensitivity angiitis, "ground base disease", requires investigation for possible underlying immunity abnormalities or neoplasms.

Aged↗
PubMed1978

[Direct examination in immunofluorescence of temporal artery sections. Value and limitations (author's transl)].

Although invariably seen with immunofluorescence in Giant Cell Temporal Arteritis, deposits of immunoglobulins and complement in the wall of the temporal arteries is nevertheless not specific to his condition. The results of the preliminary study reported here would seem to indicate that this phenomenon is related to the dysimmune state. A simple investigation, temporal artery biopsy with examination in immunofluorescence may be used to provide evidence for a diagnosis of circulating immune complex disease, the type of which can be defined only by the clinicopathological and biological context. Thus the practical value of temporal artery biopsy goes far beyong giant cell arteritis only.

Complement System Proteins↗