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Biomedical subjects

C Desgranges

Publications and source records attributed to C Desgranges.

At least 91 records · Page 5Linked to original sources
PubMed1991

Induction of cell cycle-dependent genes during cell cycle progression of arterial smooth muscle cells in culture.

Serum stimulation of arterial smooth muscle cells in culture induces a progression through the cell cycle and cell proliferation. Most genes previously described as cell cycle-dependent in various cell types also demonstrate a cell cycle-dependent expression in arterial smooth muscle cells. As in other cell types, these genes can be classified into three groups according to their mode of expression: "immediate early" genes (c-fos, c-myc, ...), "delayed early" genes (2F1, ...), and "late-G1" genes (proliferating cell nuclear antigen, thymidine kinase, . . .). In addition to these previously described genes, three genes isolated from a cDNA library of stimulated smooth muscle cells have been demonstrated to be cell cycle-dependent: A21, the rat JE gene, and L51 can be classified as "immediate early" genes, while M11 represents a new member of the "delayed early" gene family.

Animals↗
PubMed1991

Toxicity and activity of purified trichosanthin.

Trichosanthin was purified from fresh Chinese root tubers of Trichosanthes kirilowii and evaluated for anti-HIV activity. Trichosanthin inhibited syncytium formation between infected H9 cells and uninfected Sup-T1 cells from 0.5 to 4 micrograms/ml. Trichosanthin also inhibited HIV replication in H9 and CEM-SS cells at 1 microgram/ml, but was toxic for MT-4 cells (HTLV-I-positive), at doses greater than 0.25 microgram/ml. This new purification procedure confirms the anti-HIV activity of trichosanthin on some cell lines in different biological assays.

Amino Acids↗
PubMed1991

Characterization and large production of human monoclonal antibodies against the HIV-1 envelope.

Peripheral blood lymphocytes from a volunteer immunized with a recombinant vaccinia virus VSC-25 expressing the gp160 env protein of HTLV-IIIB strain and from an asymptomatic HIV-infected individual were immortalized by Epstein-Barr (EBV). Clones which secrete human monoclonal antibodies from the two individuals (DZ, IgG1, lambda and C31, IgG1, kappa) were obtained and were stable for more than 2 years. The two monoclonals were directed against the gp160 env protein of HIV, DZ directed against the gp41 and C31 directed against the gp120. C31 was group-specific, whereas DZ was directed against the HTLV-IIIB and HTLV-RF strains. The epitope recognized by DZ was mapped to the carboxy terminus of the gp41, by expression of HIV DNA fragments in a yeast system and peptide analysis. The C31 epitope was not expressed by the yeast library and not present among the peptides which were tested. Monoclonal antibodies had no inhibitory effect in an HIV-induced cell fusion assay, but DZ showed a weak neutralizing activity against the HTLV-IIIB strain. Cloned EBV-transformed cell lines were fused to a murine myeloma, which allowed the heteromyeloma to be cultivated in serum-free medium. The monoclonal antibodies were produced in large quantity in a hollow-fibre reactor at defined culture conditions and purification procedures.

Animals↗
PubMed1990

Evidence for diversity of Plasmodium falciparum sporozoite surface antigens derived from analysis of antibodies elicited in humans.

We have compared the reactivities of antibodies developed by individuals frequently exposed to Plasmodium falciparum infections with the epitopes contained within the repeats of the circumsporozoite (CS) protein and their reactivities with the epitopes of a native molecule(s) accessible on the sporozoite surface. Results of direct-binding assays and competition assays between artificial and native molecules or between human antibodies and anti-CS monoclonal antibodies suggest that humans respond preferentially to epitopes not contained within the repeats of the CS protein and probably not contained in the whole CS protein. Human monoclonal antibodies reactive with P. falciparum sporozoite surface antigens were produced by Epstein-Barr virus transformation of human lymphocytes. Their pattern of reactivity with sporozoites from a number of different isolates indicates the existence of several distinct epitopes on the parasite surface. Differences between isolates and between sporozoites within a given sample were observed. No single human monoclonal antibody capable of detecting an epitope expressed in all the parasites studied was found.

Animals↗
PubMed1989

(E)-5-(2-bromovinyl)uridine requires phosphorylation by the herpes simplex virus (type 1)-induced thymidine kinase to express its antiviral activity.

(E)-5-(2-Bromovinyl)uridine (BVUrd), the riboside counterpart of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVdUrd), effected a dose-dependent inhibition of viral progeny formation and viral DNA synthesis in herpes simplex virus type 1 (HSV-1, strain KOS)-infected human (E6SM) diploid fibroblast cells. BVUrd was directly phosphorylated in HSV-1-infected cells, presumably by the virus-encoded thymidine kinase (TK), since (i) BVUrd was not phosphorylated by extracts of cells infected with a HSV-1 strain deficient in TK expression and (ii) the phosphorylation was inhibited by a polyclonal anti-HSV-1 antibody. Within the HSV-1-infected cells, BVUrd was incorporated into the viral DNA as BVdUMP (BVdUrd 5'-monophosphate). This incorporation may account for the antiviral action of BVUrd, and implies that, following its initial phosphorylation by the viral TK, BVUrd is converted to its 2'-deoxy counterpart, most likely at the 5'-diphosphate level (BVUDP----BVdUDP).

Antiviral Agents↗
PubMed1989

Human monoclonal antibodies with a protective activity against tetanus toxin.

The antibodies and their protective activity in response to tetanus toxoid in man were studied by producing human antitetanus monoclonal antibodies after transformation of peripheral blood lymphocytes with Epstein Barr virus. Two human monoclonal IgG that reacted with the heavy chain of the toxin were obtained. One of them binds the COOH-terminal moiety and the other the NH2-terminal moiety. Only the NH2-terminal specific monoclonal antibody neutralized toxin in mouse, but in doses approximately 100-fold higher than those of a polyclonal antiserum. However, the association of these 2 antibodies was protective with doses lower than necessary for the monoclonal antibodies alone. To replace the polyclonal antibodies used, a good protection could be achieved by mixed human monoclonal antibodies against different epitopes of tetanus toxin.

Animals↗
PubMed1988

Glomerulonephritis in common marmosets infected with Plasmodium brasilianum and Epstein-Barr virus.

Plasmodium brasilianum causes chronic quartan malaria in the common marmoset Callithrix jacchus, whereas Epstein-Barr virus (EBV) infection is followed by an infectious mononucleosis-like syndrome that resolves. We infected weanling marmosets with one or both of these pathogens. Timing of the infections influenced outcome. Six animals were simultaneously infected with both agents; four became seriously ill (with accompanying proteinuria and edema) and either died or were killed. Histopathology indicated that glomerulonephritis had developed. The two survivors had more-prolonged parasitemia than did animals infected with P. brasilianum alone, as did animals infected with EBV before P. brasilianum. Five of the six simultaneously infected animals had absent or low titers of antibody to Epstein-Barr viral capsid antigens when compared with the other EBV-infected animals. Our results suggest that combined infection may be part of the etiology of quartan malarial nephropathy.

Animals↗
PubMed1988

[Lipoprotein-dependent synthesis of prostacyclin in smooth muscle cells].

Low (LDL) and high density lipoproteins (HDL) stimulated prostacycline (PGI2) synthesis in rabbit and human aorta smooth muscle cells growing in culture. The lipoproteins were added to the cells in concentrations equal to that of cholesterol. It was shown that HDL exerted a stronger stimulating effect as compared to LDL. The maximal effect was observed with HDL3. HDL3 isolated from blood serum of healthy volunteers appeared to be more active in PGI2 synthesis promotion than those of CDH patients with documented coronary atherosclerosis. Purified Apo A-1 stimulated the transformation of [14C]arachidonic acid into the products of its metabolism with increased accumulation of 6-keto-PGF1 alpha among labeled metabolites. Estradiol (1.10(-7) M) showed a stimulating effect; norepinephrine (1.10(-6) M) and progesterone (1.10(-7) M) showed an inhibiting effect, whereas corticosterone (1.10(-6) M) and deoxycorticosterone (1.10(-6) M) did not influence the rate of LDL-dependent PGI2 synthesis.

Animals↗
PubMed1987

High affinity human monoclonal antibodies directed against hepatitis B surface antigen.

Peripheral blood mononuclear cells from donors immunized with hepatitis B vaccine (Pasteur Hevac B) were transformed with Epstein-Barr virus. Two polyclonal cell lines, producing antibodies to hepatitis B surface antigen were established and cloned. Seven clones were isolated; they secreted between 10 and 20 micrograms/ml of HBs specific IgG1 kappa or lambda antibody with anti-HBs titer of 300-800 IU/ml. These human antibodies expressed the anti 'a' specificities and had high affinity and avidity; their potential use as reagents for hepatitis B virus detection and for passive immunotherapy is under study.

Antibodies, Monoclonal↗
PubMed1987

Epstein-Barr virus-specific transcription in normal and malignant nasopharyngeal biopsies and in lymphocytes from healthy donors and infectious mononucleosis patients.

Cytoplasmic RNA was prepared from biopsy material obtained from the nasopharynx of normal individuals and nasopharyngeal carcinoma (NPC) patients. Similar RNA preparations were prepared from lymphocytes of healthy donors and infectious mononucleosis patients. RNA was radioactively labelled in vitro and hybridized to cloned fragments of B95-8 Epstein-Barr virus (EBV). In all seropositive cases the minimum pattern of EBV-specific RNA expression was like that observed previously in latently infected, EBV-positive lymphoblastoid cell lines or Burkitt's lymphoma biopsies. A novel observation was that all of the control biopsies from normal nasopharynxes expressed EBV-specific RNA, some of which appeared to be associated with a more active state of EBV infection. The pattern of expression in NPC patients was similar to that of the normal donors but showed some variations in complexity. In general the virus-specified small RNAs were not present in normal nasopharyngeal tissue but were expressed in the NPC biopsies.

Biopsy↗
PubMed1987

[Human monoclonal anti-cytomegalovirus antibodies].

Specific human monoclonal anti-CMV antibodies have been isolated and characterized. The first patient had a chronic T cell lymphocytic leukaemia and a subclinical CMV infection developed at the same time as a monoclonal peak of kappa IgG3. The purified F (ab')2 fragment of the IgG3 had an intense anti-CMV activity. A second monoclonal antibody, also a kappa IgG3, was isolated in a non-immunodepressed patient with a primary CMV infection (chronic pyrexia and hepatitis). The immunotransfer showed that the anti-CMV IgM and IgG of the patient's serum reacted particularly with the p51 protein of virus capsid. The monoclonal IgG3 was specific for the same p51. The third monoclonal anti-CMV Ig studied was synthesized in vitro by the B lymphocytes of a renal transplant patient immortalized by the Epstein-Barr virus. This kappa IgM produced continuously reacted strongly with the nucleus of the cells infected by the CMV. Human monoclonal anti-CMV antibodies could be used for the early detection of viral antigens by immunofluorescence and might also be used to treat severe cases of CMV infection.

Adolescent↗