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P Chardon

Publications and source records attributed to P Chardon.

At least 73 records · Page 4Linked to original sources
PubMed1986

Swine chromosomes: flow sorting and spot blot hybridization.

Flow cytometry analysis was applied to swine chromosomes prepared from phytohemagglutinin (PHA) stimulated peripheral blood lymphocytes. Flow karyotypes from both sexes and from t(3;7) translocation carrier females were obtained. A certain number of chromosome pairs could be assigned to various peaks. In fact, 13 peaks were observed for 18 autosomal pairs plus X and Y. Moreover, abnormalities owing to the t(3;7) translocation were readily observable. The number of base pairs for chromosomes associated with the various peaks was estimated by comparison with human flow karyotypes. The following four peaks were thus sorted: the peak assumed to represent the translocated chromosome 7 plus the normals associated with it; the corresponding peak from a normal swine; the peak assumed to contain among others the normal chromosome 7; and finally the peak corresponding to swine chromosome 1. Chromosomes of each peak were collected on Pall Biodyne membrane. Following appropriate denaturation and prehybridization, the four samples were hybridized with a human leucocyte antigen (HLA) class I 32P-labelled cDNA probe, representing most of the coding sequence of the HLA B7 gene. The results confirmed previous data from other techniques that assigned the swine MHC(SLA) to chromosome 7. Subsequently, sorted samples were hybridized with a porcine genomic Interferon alpha probe in order to confirm the mapping of this gene family on porcine chromosome 1.

Animals↗
PubMed1986

DNA polymorphism in the major histocompatibility complex of man and various farm animals.

In the past few years it has been possible by combining enzymatic cleavage of genomic DNA and the Southern blot hybridization technique to explore the endonuclease recognition site polymorphism of the MHC. HLA class I and DR and DQ alpha and beta class II specific probes as well as human C4 and Bf class III probes were used. All these probes were shown to cross-hybridize with DNA from pigs, cattle, sheep and horses. Hybridization of human genomic DNA with a class I probe showed 15-25 bands per genome depending on the enzyme used. Distinct endonucleases generated clusters of restriction fragments (RF) in HLA-informative families which correlated with HLA specificities. While numerous clusters were found associated with HLA-A alleles almost no cluster was related to HLA B or C specificities. Similarly, class II probes provided a large number of clusters. The existence of these clusters suggested that some polymorphic restriction sites are found in strong linkage disequilibrium and that the underlying mechanism might be gene conversion with heteroduplex correction. Since the degree of polymorphism detected by RF appears to be greater than the polymorphism defined by more traditional methods stronger associations between RF and pathological conditions are to be expected. Southern blot analysis was applied to unrelated pigs and sheep, as well as to families. Preliminary studies have also been performed on a few unrelated cattle and horses. Depending on the endonuclease used the HLA class I probe hybridized with around 15 bands in MHC heterozygous pigs and ruminants while up to 20 bands were found in horses. Therefore, a several-fold greater number of potential class I genes exist compared to those actually expressed. With the class II beta probe, cattle and sheep showed around 10 bands whereas 15 were observed in pigs and around 20 in horses. Based on limited results obtained with DQ alpha and beta probes and with the DR alpha probe there appeared to be fewer of these respective genes. Only one C4 gene has been detected in pig and this gene maps within the SLA region. Hybridization with the human C4 probe in cattle, sheep and horses revealed two to four bands which could possibly account for two C4 genes. To date their linkage to the MHC has not been established. The Southern blot hybridization technique represents a powerful tool for future immunogenetic studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Restriction fragment length polymorphism of the major histocompatibility complex of the pig.

Human HLA cDNA probes were used to analyze the restriction fragment length polymorphism (RFLP) of the SLA major histocompatibility complex in swine. Cellular genomic DNA from 19 SLA homozygous pigs representing 13 different haplotypes was digested with restriction endonucleases Eco R1, Hind III, or Bam H1, separated by electrophoresis, and transferred onto diazobenzyloxymethyl paper by the Southern blot technique. The blots were probed with 32P-labeled class I or beta-DR class II cDNA. Depending on the haplotypes and the endonucleases used, seven to ten restriction fragments hybridized with the class I probe, and five to seven with the beta-DR probe. Their sizes ranged from 3.4 to 22 kilobase-pairs. Few bands were common to all 13 haplotypes. With all but one haplotype, identical autoradiogram patterns were obtained from unrelated, but phenotypically SLA-identical pigs, suggesting that most of the RFLP revealed were controlled by the SLA region. Further polymorphism was found in a group of seven unrelated pigs which typed serologically as SLA A15 C1 B18 homozygotes but could be divided into two subgroups, with five animals in one subgroup and two in the other, when the genomic DNA was hybridized with the class I probe. When the class II beta-DR probe was tested on the same seven pigs, another subdivision was seen, and this correlated with MLR data. These results demonstrate that HLA class I and class II probes can be used to identify certain well-established SLA haplotypes and to identify subclasses within at least one SLA haplotype.

Animals↗
PubMed1985

Analysis of the sheep MHC using HLA class I, II, and C4 cDNA probes.

Four cDNA probes for the human major histocompatibility complex (MHC) were used to investigate the sheep MHC, in conjunction with serological typing for ovine lymphocyte antigen (OLA). Lymphocytes from a family (two parents and five offspring) of Romanov sheep were subjected to genomic DNA digestion by the restriction endonuclease Eco RI, followed by gel electrophoresis. A single Southern blot representing all seven individuals was then consecutively hybridized with the class I, alpha-DC, beta-DR, and C4 probes, which were originally designed to identify HLA class I, class II (DC and DR), and C4 products, respectively. Using each of the three class I/class II probes, several bands showing DNA polymorphism were detected. The segregation of these bands in the five offspring exactly paralleled the OLA haplotype segregation established by serological typing. A further eight individuals carrying haplotypes which were phenotypically identical to those in the above-mentioned family showed bands in the corresponding positions when tested with the same three probes. Using the C4 probe, no polymorphism was detected in these fifteen individuals.

Animals↗
PubMed1985

[Effect of exclusive enteral feeding with Enteronutril on serum lipids].

Ten patients aged between 18 and 73 years admitted to our intensive care unit were placed on exclusive artificial nutrition with Enteronutril receiving on average 2.855 +/- 496 kcal/day (715 +/- 125 g). This solution is poor in lipids (1.5%) and contains no linoleic acid (C18:2). Its effects on serum lipids were analysed after 5, 10 and 15 days of treatment. Total cholesterol (TC) and phospholipids (PL) showed no significant change. However, triglycerides (TG) rose on d15 and pre-beta-lipoproteins were significantly higher on d5. The latter rose further from d10 to d15. The C18:2 fraction of total lipids (TL) fell precipitously on d5 (-50%). Although C18:2 remained stable from d5 to d10, a new, slower decrease occurred from d10 to d15. This decrease was accompanied by a specific rise in oleic (C18:1) and palmitoleic (C16:1) acids. Palmitic (C16:0) and stearic (C18:0) acids were unaffected. Arachidonic acid (C20:4) remained within normal limits up to d15. Eicosatrienoic acid which was measurable on d0 presented no significant rise during the course of the study. The changes in C18:2 were inversely proportional to those of C18:1 or C16:1. This translated a lack of C18:2 relative to delta 9 desaturase (freed of the inhibition usually exerted by C18:2). These results showed that the body could maintain a sufficient level of linoleic acid to synthesize arachidonic acid by drawing on its C18:2 reserves from fatty tissue. Nevertheless, these reserves were progressively exhausted beyond d10, thereby causing a shortage of arachidonic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Molecular genetic analyses of the major histocompatibility complex in pig families and recombinants.

Five HLA probes, one corresponding to class I genes, two corresponding to distinct class II light chain genes, DR beta and DQ beta, and two to class II heavy chain genes, DR alpha and DQ alpha, were used to analyse the genomic DNA of the pig. Three informative SLA typed families and four SLA recombinants were studied by Southern blot analysis. About 16 restriction fragments, generated by EcoR1 or Hind III endonucleases, were revealed for each individual, either with the class I probe or the DR beta probe. The number of restriction fragments which hybridized with the other probes was generally lower. Several restriction fragment-length polymorphisms were found and these segregated with SLA haplotypes. The studies on SLA recombinants showed that SLA DR beta- and DQ alpha-like genes are probably tightly clustered within the SLA-D-MLR region.

Animals↗
PubMed1984

Assignment of MHC in swine to chromosome 7 by in situ hybridization and serological typing.

Mapping of the MHC in swine (SLA) was achieved by direct in situ hybridization to chromosome preparations. We took advantage of the fact that the cDNA probe coding for class I HLA-B7 antigen cross-hybridizes with swine genomic DNA. By nick-translation, 35S nucleotides were incorporated to a specific activity of 2,7 10(7) cpm/ug. Analysis of 91 randomly selected labeled metaphases revealed highly significant labeling on chromosome 7. The SLA complex is most probably located at the proximal half of the long arm, as indicated in families carrying a modified chromosome 7 and heterozygous for SLA. The abnormal chromosome was always inherited with a specific haplotype whereas the other parental haplotypes were found in association with the normal 7.

Animals↗
PubMed1983

Expression of beta 2-microglobulin on preimplantation pig embryos.

The expression of beta-2 microglobulin (beta 2m), a protein associated with the histocompatibility antigens of the pig complex (SLA), was studied in preimplantation embryos between the segmentation stage and the beginning of elongation (day 12). The antigen was visualized at the ultrastructural level by immunocytochemical techniques using peroxidase or colloidal gold particles as labels. beta 2m expression appeared to parallel trophoblast differentiation. No positive reaction was obtained before the early blastocyst stage. From this stage on, labelling was observed on the apical surface of the trophectoderm cells.

Animals↗
PubMed1983

Monoclonal antibodies to HLA recognize monomorphic and polymorphic epitopes on BoLA.

Fourteen monoclonal antibodies recognizing monomorphic and polymorphic epitopes on class I and class II antigens of the human MHC have been assayed on lymphocytes of a panel of 20-150 BoLA typed bovine animals from 12 different breeds. Some monomorphic antibodies cross-reacted and others did not. Two polymorphic monoclonal antibodies in man recognize a polymorphism in cows that follows allospecificities (BoLA-w3, w9) already described. Immunoprecipitation experiments with monomorphic anti-B2m and anti-HLA-DR monoclonal antibodies have shown that these cross-reactions concern BoLA antigens. They also revealed that Ia-like antigens in cattle present the same two chain features characterized in other species.

Animals↗
PubMed1982

Monoclonal antibodies as a tool for phylogenetic studies of major histocompatibility antigens and beta 2-microglobulin.

The cross-reactivity of several monoclonal antibodies recognizing monomorphic determinants of human HLA-A, B, C, and DR antigens and human beta 2-microglobulin (beta 2m) has been studied on peripheral blood leukocytes in 24 different species. An monoclonal HLA-A-, B-, and C-specific antibody and four monoclonal HLA-DR-specific antibodies cross-reacted with cells from all the primate species tested. Furthermore, antibodies HLA-DR-specific were positive with peripheral blood leukocytes (PBL) from cows, goats, sheep, horses, and dogs. Two monoclonal beta 2m-specific antibodies, which were positive with PBL from certain primates, also reacted with cells from cows, goats, sheep, horses, and dogs. Two other beta 2-m-specific antibodies reacted only with PBL from chimpanzees. No reaction could be detected with all our reagents in other classes tested (birds, reptiles, amphibians, and Teleostei).

Animals↗
PubMed1982

The pig histocompatibility system SLA: serological study on a group of antigenic specificities.

The report presents an analysis of a group of class I SLA reagents which were highly correlated within one cluster in a previous analysis. Further population and family studies, and selected purification of several of these reagents led to the identification of 4 distinct specificities, namely SLA A 15, B 18, C 1 and A 16. Three of them, SLA A 15, B 18 and C 1, are actually in strong linkage disequilibrium and represent the main SLA haplotype in the Large White breed. SLA A 16 is present essentially in the Landrace breeds. SLA A 16 displays a strong cross-reaction with SLA A 15 and there is another specificity in linkage disequilibrium with SLA A 16 which cross-reacts with SLA B 18. Altogether, the strong linkage disequilibrium and the high degree of cross-reactivity among the allelic products of the SLA complex explain the failure to detect the diversity of our reagents in previous studies.

Absorption↗
PubMed1981

Characterization of class II histocompatibility antigens in pigs.

The D region of the SLA complex in the pig has been studied by immunochemical and sequential immunoprecipitation techniques as well as the redistribution of membranous antigens (capping). The molecules identifies by the anti-Ia sera were solubilized by NP 40, purified on lectin and precipitated. Polyacrylamide gel electrophoresis under dissociating conditions shows that these molecules are made up of two chains whose molecular weights are 32000 and 26000 daltons respectively. Sequential immunoprecipitation and capping experiments indicate that two distinct types of Ia molecules exist. At least a part of the nylon-wood-adherent lymphocyte population express both types of molecules.

Animals↗
PubMed1981

[Pharmacokinetics of intravenous non-steroidal anesthetics].

Even though the anesthetic agents thiopental, ketamine, propanidid and etomidate all belong to very different chemical families they are all characterized by a very large degree of liposolubility. This explains their rapid penetration into the brain. The pharmacokinetic model of thiopental is a three compartment model. There is strong protein binding and only the free fraction is active. The very short action of the product after a single injection is due to the rapid redistribution of the agent into the muscle mass because its hepatic metabolization is very slow. However, when given over prolonged time the adipose compartment plays an important role in the mixture of the product, explaining the prolonged sleep produced. The central depressant actions of thiopental and consequently its action on CMRO2 depend on the initial dose and the route of administration. A single and massive injection produces a small and temporary reduction in the CMRO2 even though the plasmic concentration is high. In contrast prolonged intravenous infusion produces more severe and longer lasting depression of the CMRO2. The pharmacokinetic model of ketamine is tri-compartmental. There is weak protein binding. After IV injection ketamine rapidly enters the brain and the maximum concentration is reached one minute later. After that the cerebral concentration rapidly falls as does the plasma level. Signs of waking are seen at a concentration of 130 micrograms per gram of tissue. An increase in the dose of ketamine does not much influence the duration of analgesia but increase the waking time. This suggests that its indication in ambulatory anesthesia should be looked at with care. It is metabolized by the liver with the formation of several metabolites of which some are active. The kinetics of propanidid can be explained on the basis of a monocompartmental model. The speed of the fall in plasma level of the product is related to the speed of injection. High plasma concentrations mobilize a larger quantity of plasma pseudo-cholinesterases, increasing thus the speed of degradation. The product is rapidly hydrolized (plasma and liver cholinesterases). The duration of action is longer when used at low doses or when it is administered at a constant dose. Propanidid does not have any accumulative effect. The kinetics of etomidate follow a tri-compartmental model. It is very rapidly and largely distributed in the organism, the peak cerebral concentration being reached in less than one minute. There is strong protein binding. Repeated administration of the drug produces an increase in anesthetic sleep but also a delay in recovery. Etomidate is hydrolized by hepatic esterases.

Anesthesia, Intravenous↗
PubMed1981

[Prognostic value of cutaneous delayed hypersensitivity tests in patients with acute decompensation of chronic respiratory failure. Relation to the nutritional state].

This study involved 15 chronic respiratory failure patients admitted to intensive care because of acute decompensation. Study of delayed hypersensitivity skin tests made it possible retrospectively to divide these patients into two groups according to whether tests were positive or negative. Group A: patient positive on admission and remaining so: or negative becoming positive on the 10th day = 8 patients. Group B: patient negative and remaining negative; or positive on admission and becoming negative on the 10th day = 7 patients. In group A, 7 patients survived, whilst one died of an intercurrent condition. In group B, all the patients died. Study of nutritional balance showed a deficiency in protein metabolism--with hypoproteinaemia, hypoalbuminaemia, decrease in creatine index, negative nitrogen balance--combined with a deficiency in trace elements. Such disturbances were particularly marked in group B. Under the influence of nutritional therapy, these deficiencies tended to return to normal in reacting subjects but worsened in non-reacting subjects. In patients of this type, nutritional therapy must be administered well before acute decompensation. It should be able to prevent the latter in a substantial number of cases.

Aged↗