Search PubMed⌕ Search

Biomedical subjects

M Girard

Publications and source records attributed to M Girard.

At least 253 records · Page 14Linked to original sources

A domain of SV40 capsid polypeptide VP1 that specifies migration into the cell nucleus.

In order to identify the determinants responsible for the nuclear migration of simian virus 40 (SV40) polypeptide VP1, the 5'-terminal portion of the SV40 VP1 gene was fused with the complete cDNA sequence of poliovirus capsid polypeptide VP1 and the hybrid gene was inserted into an SV40 vector in place of the normal SV40 VP1 gene. Deletions of various length were generated in the SV40 VP1 portion of the hybrid gene, resulting in a set of truncated genes encoding 2-40 NH2-terminal amino acids from SV40 VP1, followed by poliovirus VP1. Monkey kidney cells were infected by the deleted hybrid viruses in the presence of an early SV40 amber mutant as helper, and the subcellular localization of the fusion proteins was determined by indirect immunofluorescence using an anti-poliovirus VP1 immune serum. The presence of the first 11 NH2-terminal amino acids from SV40 VP1 was found to be sufficient to target the fusion protein to the cell nucleus. Deletions extending from the NH2- towards the COOH-terminal end of the protein were next generated. Transport of the SV40 VP1-poliovirus VP1 fusion polypeptide to the nucleus was abolished when the first eight amino acids from SV40 VP1 were deleted. Thus the sequence of the first eight NH2-terminal amino acids of SV40 VP1 appears to contain a nuclear migration signal which is sufficient to target the protein to the cell nucleus.

Antigens, Polyomavirus Transforming↗

Genetic heterogeneity of yellow fever virus strains from Africa and the Americas.

Isolates of yellow fever (YF) virus from Africa (Senegambia, Central African Republic, Ivory Coast, Burkina Faso) and from South America (Panama, Ecuador, Trinidad) were examined by oligonucleotide fingerprinting of the 40S genome RNA. Geographically isolated and epidemiologically unrelated viruses were very distinct. On the basis of the T1 oligonucleotide fingerprints of each isolate, four geographical variants (topotypes) of YF virus isolated within the same period of time have been established. The Ivory Coast and Burkina Faso topotypes were similar. In the Central African Republic, two variants could be found exhibiting 70 to 75% homology to one another. In South America, the three analysed strains exhibited only about 70% homology, but could be classified in the same topotype. The oligonucleotide fingerprints of the genome RNA offered a useful tool for the understanding of YF virus variability.

Aedes↗

Automation in blood banking.

During the past decade, automation took a major place in blood transfusion laboratories. Now many centers have purchased automated equipment and subsequently undertaken the computerization of their activities. The aim of this paper is to review the state of the art in the field of automation and to try to estimate future tendencies.

Automation↗

Mutations conferring resistance to neutralization with monoclonal antibodies in type 1 poliovirus can be located outside or inside the antibody-binding site.

Antigenic variants resistant to eight neutralizing monoclonal antibodies were selected from wild (Mahoney) and attenuated (Sabin) type 1 infectious poliovirions. Cross-immunoprecipitation revealed interrelationships between epitopes which were not detected by cross-neutralization. Operational analysis of antigenic variants showed that seven of eight neutralization epitopes studied were interrelated. Only one neutralization epitope, named Kc, varied independently from all the others. This latter, recognized by C3 neutralizing monoclonal antibody, was present not only on infectious virions but also on heat-denatured (C-antigenic) particles and on isolated capsid protein VP1. Loss of the neutralization function of an epitope did not necessary result from the loss of its antibody-binding capacity. Such potential, but not functional, neutralization epitopes exist naturally on Mahoney and Sabin 1 viruses. Their antibody-binding property could be disrupted by isolating antigenic variants in the presence of the nonneutralizing monoclonal antibody and anti-mouse immunoglobulin antibodies. Single-point mutations responsible for the acquisition of resistance to neutralization in the antigenic variants were located by sequence analyses of their genomes. Mutants selected in the presence of C3 neutralizing monoclonal antibody always had the mutation located inside the antibody-binding site (residues 93 through 103 of VP1) at the amino acid position 100 of VP1. On the contrary, antigenic variants selected in the presence of neutralizing monoclonal antibodies reacting only with D-antigenic particles had mutations situated in VP3, outside the antibody-binding site (residues 93 through 103 of VP1). The complete conversion of the Mahoney to the Sabin 1 epitope map resulted from a threonine-to-lysine substitution at position 60 of VP3.

Amino Acid Sequence↗

Highly infectious plasmids carrying poliovirus cDNA are capable of replication in transfected simian cells.

We examined events leading to production of infectious poliovirus upon transfection of simian cells with plasmids carrying poliovirus cDNA and simian virus 40 transcription and replication signals. The nature of the simian virus 40 promoter upstream from the poliovirus cDNA had no influence on its infectivity. A high specific infectivity was correlated with plasmid replication, dependent on expression of T antigen either encoded by the plasmid or present in host cells (COS-1).

Animals↗

[Prolactin stimulation test using TRH in affective disorders (72 cases)].

Authors report results of stimulation test of prolactin by T.R.H. in 72 inpatients with affective disorders. They find well known effects of physiological factors (age, sex), and treatments (neuroleptics, lithium, L-Dopa). They did statistical analysis on plasma levels before and after T.R.H. stimulation. This test has no value for differential diagnosis between types of depressions. But it shows particular relation between high levels of prolactin and bipolarity.

Adult↗

S-s-U-phenotype in a Caucasian family.

The S-s-U-blood group phenotype, commonly detected in Black populations, was found in a Caucasian family in which 4 homozygous U-negative members exhibit this phenotype. The erythrocyte blood group antigens and membrane glycoproteins from these donors have been serologically and electrophoretically characterized and compared to the U-negative red cells from Black people. Caucasian and Black S-s-U-red blood cells behaved identically since both lack Ss and U antigens and the minor red-cell membrane glycophorin B.

Black People↗

[Psychiatric manifestations of Steinert's disease].

Authors report one case of psychiatric manifestations of Steinert's disease, with biological data. They compare it with historical and actual descriptions of these manifestations, particularly for clinical and biological symptomatology. Main hypothesis is a central localization of this polysystemic process, under a genetical determinism.

Electroencephalography↗

Nuclear localization of poliovirus capsid polypeptide VP1 expressed as a fusion protein with SV40-VP1.

The poliovirus cDNA fragment coding for capsid polypeptide VP1 was inserted between the EcoRI and BamHI sites of SV40 DNA, generating a chimaeric gene in which the sequence of the 302 amino acids (aa) of poliovirus capsid polypeptide VP1 was placed downstream from that of the 94 N-terminal aa of SV40 capsid polypeptide VP1. The resulting defective, hybrid virus, SV40-delta 1 polio, was propagated in CV1 cells using an early SV40 mutant, am404, as a helper. Cells doubly infected by SV40-delta 1 polio and am404 expressed a 50-kDal fusion protein which was specifically immunoprecipitated by polyclonal and/or monoclonal antibodies raised against poliovirus capsids or against poliovirus polypeptide VP1. Examination of the infected cells by immunofluorescence after staining with anti-poliovirus VP1 immune sera revealed that the fusion protein was mostly located in the intra- and perinuclear space of the cells, in contrast to the exclusively intracytoplasmic location of genuine poliovirus VP1 polypeptide that was observed in poliovirus-infected cells. This suggests that the N-terminal part of the SV40-VP1 polypeptide could contain an important sequence element acting as a migration signal for the transport of proteins from the cytoplasm to the nucleus.

Animals↗

Immunogenicity of hepatitis B vaccine in guinea-pigs, mice and man.

The immunogenicity of the hepatitis B vaccine Hevac B Pasteur was assayed in guinea-pigs. The reproducibility of the test was determined by comparing the ImD50 of two samples of vaccine in 12 and eight groups of 40 animals each. The variation coefficient between groups was approximately 30%, similar to that found for other vaccines assayed in biological tests in vivo. The sensitivity of the test was determined by comparing the dose response curves in mice, guinea-pigs and humans. The results showed that one ImD50 in man (after one injection) was approximately equivalent to 3 ImD50 in guinea pigs and to 100 ImD50 in Balb/C mice. Stability of Hevac B at 37 degrees C was assayed by determining in guinea-pigs the ImD50 of a series of samples of vaccine that had been incubated at 37 degrees C for varying amounts of time. The immunogenicity of the vaccine was found to decay with a half-life of ten to 15 days at 37 degrees C.

Adult↗

Thermostability and efficacy in the field of a new, stabilized yellow fever virus vaccine.

Samples of the new, stabilized 17D virus vaccine from Pasteur Vaccins, France were stored for up to six months at +10 +/- 2 degrees C in the hospital of Bouar, Central African Republic. Each month during this study, the vaccine ampoules were put into an ice box without ice and taken into the field to be used as part of a vaccination programme. No significant loss of infectious virus titre was observed under these conditions. Efficacy of the vaccine was determined from percent seroconversions in vaccinated children. No loss of efficacy of the vaccine was observed after five months storage at +10 degrees C and five trips in the field, confirming the high heat stability of the new vaccine.

Antibodies, Viral↗