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C Salmon

Publications and source records attributed to C Salmon.

At least 19 recordsLinked to original sources
PubMed2001

Duality of gonadotropins in gnathostomes.

The glycoprotein hormone alpha subunit and two beta subunits were cloned from the ventral lobe of the pituitary gland of an elasmobranch fish, Scyliorhinus canicula. The mature alpha subunit was 96 amino acids long and showed 64-76 amino acid residues in common with alpha subunit sequences of representatives of sarcopterygians (tetrapods and dipnoi) and actinopterigyans (chondrostei and teleostei). The Scyliorhinus beta 1 subunit was 115 amino acid long and had characteristics specific to FSH beta subunits and, in particular, the two potential N-linked glycosylation sites in conserved positions. The beta 2 sequence was 112 amino acids long. The Scyliorhinus beta 2 subunit had only one potential N-linked glycosylation site at the same position as that in LH. None of the two beta subunits from Scyliorhinus displayed the two amino acid insertions shared by TSH beta subunit sequences between the fifth and the sixth cysteines as compared to actinopterygian and sarcopterygian gonadotropins. These data indicate that Scyliorhinus beta 1 and beta 2 subunits are orthologous to FSH and LH beta subunits, respectively. It is concluded that the two FSH and LH lineages were already individualized at the emergence of chondrichthyans.

Amino Acid Sequence↗
PubMed2000

Phylogenetic analysis of the vertebrate glycoprotein hormone family including new sequences of sturgeon (Acipenser baeri) beta subunits of the two gonadotropins and the thyroid-stimulating hormone.

The beta subunits of the two gonadotropins (GTH1 and GTH2) and of the thyroid-stimulating hormone (TSH) of a chondrostean fish, Acipenser baeri, were cloned. These new sequences and selected representative members of beta subunits of vertebrate glycoprotein hormones, including tetrapod follicle-stimulating hormones (FSH) and luteinizing hormones (LH), allowed us to infer the phylogenetic relationships within this family. Both distance matrix and maximum parsimony methods were used on both nucleotide and amino acid sequences, with bootstrapping evaluation over 1000 replicates. The four trees obtained had highly similar topologies. In each case, three monophylogenetic lineages, TSH, GTH1-FSH, and GTH2-LH were clearly identified. The three monophylogenetic lineages were supported by 21-23 specific characters at the amino acid level, out of a total of 121 characters. The resolved topologies within each monophyletic hormone cluster were congruent with the known phylogenetic relationships between the related species. The inferred parental relationships within gonadotropins are in agreement with data concerning their biological functions. The present study demonstrates that GTH1 and GTH2 are the actinopterygian homologues of tetrapod FSH and LH, respectively.

Amino Acid Sequence↗
PubMed1998

Heterogeneity of eel thyrotropin beta mRNAs is due to a minisatellite in the 3' untranslated region of the gene.

The aim of this study was to determine the causes of the high heterogeneity, in the number and the length, of the thyrotropin (TSH) beta mRNA in the European eel. Northern blot analysis showed that removal of the poly(A) tail did not affect this heterogeneity. PCR amplification on reverse-transcribed pituitary RNAs (RT) showed the main source of heterogeneity to be a highly variable region in the 3' untranslated region (UTR). PCR amplification of the 3' UTR from RTs and genomic DNAs demonstrated that the high variability reflected polymorphism within the eel TSH beta gene. Isolation and sequencing of 3' UTR amplification fragments showed that the variable region comprised more or less exact repetitions of a 26-42-bp fragment. The number of repetitions varied from one allele to another. This variable region could be characterized as a minisatellite. In conclusion, instability of a minisatellite in the 3' UTR of the TSH beta gene generated the multiple and widely differing TSH beta mRNAs.

Amino Acid Sequence↗
PubMed1997

Down-regulation of TSH subunit mRNA levels by thyroid hormones in the European eel.

The effects of 3,5,3'-triiodothyronine (T3) and thyroxine (T4) on alpha and thyroid-stimulating hormone (TSH) beta subunit mRNA pituitary levels were examined in a teleost, the European silver eel. Northern blot analysis showed that the number and length of mRNAs encoding TSH beta varied among individuals, a variability apparently not related to thyroidal status. When several bands were present, their intensities were summed for quantitative analysis. Increasing circulating thyroid hormones (THs) by implantation of T3 or T4 significantly decreased TSH beta mRNA levels. Depression of circulating THs by thiourea treatment increased alpha and TSH beta mRNA levels. In vitro studies showed that T3 and T4 decrease TSH beta mRNA levels in primary cultures of eel pituitary cells. In conclusion, in vivo and in vitro experiments indicate that T3 and T4 exert a negative feedback action on pituitary TSH beta mRNA level in the European eel and that this effect might be exerted, at least partly, through a direct action on the pituitary.

Animals↗
PubMed1993

[Cloning and sequence of thyrotropin beta subunit of a teleost fish: the eel (Anguilla anguilla L.)].

We obtained the sequence of eel thyrotropin beta-subunit cDNA. About 1,100 bp long, it encodes a 147-amino acid protein including a 20-residue signal peptide. We analyse homologies between angTSH beta and the other known beta-subunits taking in account the ability of mammal gonadotropins (GTH) to stimulate teleost thyroid. A peptide corresponding to mammalian CAGYC (implicated in subunit association) is original and different from its eel beta GTH2 counterpart.

Amino Acid Sequence↗
PubMed1991

[Passive immunotherapy in AIDS: transfusion of plasma rich in anti-p25 antibody (phase I trial)].

The present study is a therapeutic trial of phase I, based on the principle of passive immunotherapy in acquired immunodeficiency syndrome (AIDS). Eighteen patients with full blown AIDS (stage IV C2 of CDC) were subdivided into two groups: nine receiving every two weeks 300 ml of plasma collected from HIV-1 seropositive symptomless (stage II or III of CDC) individuals, and nine (control group) receiving 300 ml of seronegative plasma at the same rythm and for the same period. Each patient received seven transfusions. Clinical and biological results during the transfusional and post-transfusional periods are reported.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[DNA polymorphism: comparison of allelic frequencies obtained with two HVR probes in a population from Northeastern Brazil and in two other ethnic groups].

DNAS from 325 individuals representing 2 different populations (234 Brazilians and 91 Asiatics) were analysed for Restriction Fragment Length Polymorphisms (RFLPs). These DNAs were digested with Pvu II enzyme and successively hybridized to two HVR probes: alpha globin-3'HVR and Mucin-HVR. An allele frequency distribution was determined for each couple probe/enzyme and each ethnic groupe studied. The results were compared with frequencies observed in french population and we showed that there is no statistic significant difference between allele frequencies obtained with the couple probe/enzyme 3'HVR/Pvu II in Brazilian and French populations. We also showed that both populations studied (Brazilian and Asiatic) do not follow a Hardy-Weinberg balance.

Adolescent↗
PubMed1991

[Restriction fragment study (RFLP) of DNA polymorphism in criminology: quantitative and qualitative analyses beginning with dried blood and semen on various supports].

Deoxyribonucleic acid (DNA) purified from various forensic samples was characterized by RFLP (Restriction Fragments Length Polymorphism). DNA isolated from dried bloodstains and dried semen stains was digested with restriction endonucleases (HinfI, PvuII, TaqI) and fractionated by electrophoresis on 0.7% agarose gels. After transfer to a filter, DNA was hybridized with different radioactively labeled recombinant probes: with HinfI, G3, MS1, MS8, MS31, MS43, cloned from 33.6 and 33.15 Jeffreys probes, with PvuII 3'HVR, with TaqI MR24/1. This probes recognize polymorphic DNA regions, so variation between individuals at fundamental level of their DNA can be used to discriminate them. Therefore, pattern of RFLP detected by this test was used to determine the probable identity of different samples. DNA was isolated and detected by Southern blot from since 50 microliters dried bloodstains (HinfI, G3, MS1, MS31), from various specimen bloodstains and from dried semen stains. Highly variable minisatellites cloned from Jeffreys probes took more satisfaction for sensitivity than others. However, DNA polymorphism analysis can be used with caution because method limits can be perturbed interpretation of results.

Base Sequence↗
PubMed1991

[Purification and characterization of presumed thyrotropic hormone subunits of a teleost fish, the eel (Anguilla anguilla)].

We have only a partial knowledge of fish thyrotropins (TSH) and no data about peptide sequence are available. Various HPLC techniques allowed us to purify a 31.4 kDa, heterodimeric protein from saline eel pituitary extracts containing TSH activity. Partial N-terminal sequence (24 amino acids) from one subunit was strictly identical to that of eel gonadotropin II (GTH II) alpha subunit. With regard to the second subunit, 41% of the 22 amino acids identified at the N-terminus were homologous to those of bovine beta TSH and 36% were homologous to those of eel beta GTH II. Thus, the purified protein exhibits biochemical characteristics similar to those of mammalian TSH, in particular an alpha subunit common with GTH.

Amino Acid Sequence↗
PubMed1990

[Prediction of the clinical course of AIDS in a cohort of 77 seropositive persons. Importance of p24 antigen in the blood and the level of serum IgA].

Among the HIV-1 seropositive subjects detected through blood donation in Paris area who every six months voluntarily went through a thorough clinical and biological follow-up in the Institut National de Transfusion Sanguine, a cohort of 77 subjects had completed at least four biannual controls by september 1988. Upon inclusion in the study, all subjects were CDC stage II or III, none had received any treatment. Biological parameters in entrance in the study were assessed in a attempt to forecast the CD4 lymphocyte count decrease during the 18 months follow-up time. Multivariate forward stepwise analysis indicated that only p24 ag level, IgA level, and partially neopterin or Beta-2-Microglobulin levels were independently predictive of CD4 count at the end of the follow-up and of the CD4 loss at the same time. The prediction by these biological parameters is a rather poor one, 39% of the variation of CD4 lymphocyte count or 30% of the variation of CD4 loss after 18 months of the cohort follow-up being explained. In conclusion, HIV-infection seems to possess an intrinsic evolution which escapes our surveillance by biological parameters.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Perpropionic and peracetic acids destroy HIV in suspension, but do not inhibit the virus in contaminated units of blood].

The virucidal activity of peracetic and perpropionic acids was evaluated against HIV in an attempt to inactivate the virus which might contaminate blood units collected from donors. The results showed first that doses of peracids as weak as 50 ppm were able to kill the virus in free suspension, but that the doses that did not adversely affect blood components did not inactivate the virus in those components.

Acetates↗
PubMed1990

[Interviews with HIV seropositive subjects identified at the time of blood donation: consequences for pre-donation interviews].

This study is based upon an interview with 31 individuals recently detected human immunodeficiency virus (HIV) seropositive through the systematic screening of blood donations. The location of the blood donation, the type of blood donor, the risk of HIV infection, were established. Questions dealt with the use of blood donation as a diagnosis test and on the notion of an oral or written self-exclusion before the blood donation. The majority of the individuals had a classical risk factor of HIV infection and had given blood for serological testing. This data can allow an adaptation of the medical interview preceding the blood donation to the present epidemiological context of HIV infection.

Adult↗
PubMed1990

Failure to detect evidence of human immunodeficiency virus type 1 (HIV-1) infection by polymerase chain reaction assay in blood donors with isolated core antibodies (anti-p24 or -p17) to HIV-1.

Individuals with isolated and persistent core antibodies (anti-p24 or -p17) to HIV-1 are sometimes diagnosed through the systematic screening of blood donations. The significance of such serum reactivities remains unknown. Polymerase chain reaction (PCR) is a new technique allowing the direct detection of HIV-1 DNA in blood samples. In this study, PCR was used to detect HIV-1 DNA in 20 individuals with isolated and persistent core antibodies (14 anti-p24 and 6 -p17), in seven sexual partners of these individuals, in 55 HIV-1-seropositive individuals (positive controls), and in 105 HIV-1-seronegative blood donors at low risk of HIV-1 infection (negative controls). No HIV-1 DNA was detected in individuals with isolated and persistent core antibodies, in their sexual partners, or in negative control individuals, although PCR was positive in 54 of 55 seropositive control individuals. These results strongly suggest that individuals with isolated and persistent core antibodies are not infected with HIV-1.

Amino Acid Sequence↗
PubMed1990

Molecular cloning and protein structure of a human blood group Rh polypeptide.

cDNA clones encoding a human blood group Rh polypeptide were isolated from a human bone marrow cDNA library by using a polymerase chain reaction-amplified DNA fragment encoding the known common N-terminal region of the Rh proteins. The entire primary structure of the Rh polypeptide has been deduced from the nucleotide sequence of a 1384-base-pair-long cDNA clone. Translation of the open reading frame indicates that the Rh protein is composed of 417 amino acids, including the initiator methionine, which is removed in the mature protein, lacks a cleavable N-terminal sequence, and has no consensus site for potential N-glycosylation. The predicted molecular mass of the protein is 45,500, while that estimated for the Rh protein analyzed in NaDodSO4/polyacrylamide gels is in the range of 30,000-32,000. These findings suggest either that the hydrophobic Rh protein behaves abnormally on NaDodSO4 gels or that the Rh mRNA may encode a precursor protein, which is further matured by a proteolytic cleavage of the C-terminal region of the polypeptide. Hydropathy analysis and secondary structure predictions suggest the presence of 13 membrane-spanning domains, indicating that the Rh polypeptide is highly hydrophobic and deeply buried within the phospholipid bilayer. In RNA blot-hybridization (Northern) analysis, the Rh cDNA probe detects a major 1.7-kilobase and a minor 3.5-kilobase mRNA species in adult erythroblasts, fetal liver, and erythroid (K562, HEL) and megakaryocytic (MEG01) leukemic cell lines, but not in adult liver and kidney tissues or lymphoid (Jurkat) and promyelocytic (HL60) cell lines. These results suggest that the expression of the Rh gene(s) might be restricted to tissues or cell lines expressing erythroid characters.

Amino Acid Sequence↗
PubMed1990

Production and characterization of human monoclonal antibodies against core protein p25 and transmembrane glycoprotein gp41 of HIV-1.

With a view to obtaining human monoclonal antibodies against HIV-1 antigens we used the Epstein-Barr virus immortalization technique to induce lymphoblastoid cell lines from peripheral blood lymphocytes of 10 people who were seropositive for HIV-1 and had no clinical symptoms. A number of polyclonal lines were obtained which synthesized antibodies against most of the major proteins and glycoproteins of HIV-1. Three stable clones were characterized for class, secretion characteristics and specificity. Two of these clones produce antibodies which react with gp41, and the third reacts with p25. One of the anti-gp41 antibodies was found to have neutralizing activity.

Amino Acid Sequence↗