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P Horín

Publications and source records attributed to P Horín.

15 recordsLinked to original sources
PubMed2002

A second locus and new alleles in the major histocompatibility complex class II (ELA-DQB) region in the horse.

More than two nucleotide sequences of the second exon of the ELA-DQB region retrieved from a single animal and two different sequences isolated from horses homozygous in the major histocompatibility complex (MHC) region by descent indicated the existence of at least two ELA-DQB loci at the genomic level. New alleles detected by polymerase chain reaction single strand conformation polymorphism (SSCP) and defined by nucleotide sequencing of the second exon of the DQB gene(s) were described. Based on the level of nucleotide sharing, at least two groups of alleles were shown to exist. The newly defined alleles belonged preferentially to one of the groups. However, their specific locus assignment was not possible from the data collected. At least one of these alleles was shown to be transcribed. No frame-shift mutations were identified among the new alleles, although one pseudoallele containing a stop codon was identified at the genomic DNA level.

Alleles↗
PubMed2002

Two bi-allelic single nucleotide polymorphisms within the promoter region of the horse tumour necrosis factor alpha gene.

Primers based on GenBank sequences within the 5' untranslated region (UTR) of the human and horse tumour necrosis factor alpha (TNF-alpha) genes were designed and used to amplify a 522-bp product. Sequencing of five clones derived from five independent PCRs obtained from three different animals of three different breeds (Old Kladruber, Akhal-Teke and Shetland Pony) revealed a high level of sequence identity to the TNF-alpha promoter regions of other species. The existing GenBank horse sequences were confirmed and extended upstream by 230 nucleotides. Based on the sequence obtained, a new horse-specific forward primer was designed to amplify a 213-bp PCR product, which was screened for polymorphism using single-strand conformation polymorphism (SSCP). Three allelic variants of the horse TNF-alpha gene were identified and sequenced (GenBank accession numbers ADF 349558-60). Two single nucleotide polymorphisms explained the existence of the three SSCP alleles detected: C/T and T/C single base pair substitutions at positions 137 and 147, respectively. Differences in allelic frequencies between Old Kladruber and Akhal-Teke breeds were observed.

5' Untranslated Regions↗
PubMed2002

Characterization of the NRAMP1 (SLC11A1) gene in the horse (Equus caballus L.).

The complete coding cDNA sequence of the horse NRAMP1 (SLC11A1) gene was determined (GenBank accession number AF354445). The nucleotide sequence of the horse NRAMP1 gene is similar to sequences of this gene in other species. The gene contains 15 exons whose total length of 1,635 bp corresponds to 544 amino acids constituting the resulting putative protein. Hydrophobicity profile analysis of the deduced horse NRAMP1 gene product showed a nearly identical structure with the mouse NRAMP1 protein. The gene was found to be located on the short arm of ECA 6p12-13 by fluorescence in situ hybridization (FISH) analysis. Five allelic variants of the 5' untranslated region (UTR) were identified at the nucleotide sequence level. PCR-RFLP polymorphisms for NlaIII, TaqI, MspI and AciI were detected. Four out of five alleles could be detected using TaqI and MspI restriction enzymes. Their haplotype frequencies were different in four genetically distinct horse breeds.

5' Untranslated Regions↗
PubMed2001

[Biological principles of chemotherapy: cellular response as a result of its evolutionary memory].

The cell reaction to chemotherapy is based on certain general biological principles. The genetic structure of cell populations, their actual reaction to chemotherapy and the prognosis of their development are not accidental. They are determined by previous exposures to chemotherapeutic agents and thus their evolutional experience on Darwinian principles. Chemotherapy occurs always in a defined environment of the host with his active participation. A genetic variability in the host reaction to chemotherapeutic interference also exists and which in the long-term perspective is also of evolutional nature. The complex of evaluation of therapeutic procedures thus involves evaluation and influencing of the host and his variability (immunotherapy). Understanding of molecular mechanisms of the pathogenesis of disease, definition of specific genes, their expression, the role of their products and definition of possible targets of chemotherapy is at present a realistic goal of application of genomics and proteogenomics in medicine. The new philosophy in medicine is thus based on respecting individuality in diagnosis, treatment and prognosis. We only can wish that the trend of respecting individuality will be applied in the future, and not only in medicine.

Animals↗
PubMed1998

Polymorphism of Old Kladruber horses, a surviving but endangered baroque breed.

Analysis of MHC class I and class II polymorphism, as well as data from other polymorphic systems (non-MHC lymphocyte alloantigen, blood groups systems, biochemical polymorphisms and microsatellite loci), was used to characterize the extent and distribution of the genic polymorphism of Kladruber horses. A breed-characteristic distribution of the MHC polymorphism was found. The repertoire of defined MHC class I specificities was restricted, especially in the grey subpopulation and in stallions, but a high frequency of blanks suggests the possible existence of undetected specificities. Despite the small population size and a relatively high degree of inbreeding, high heterozygosity in MHC haplotypes has been conserved. The extent of polymorphism and the degree of heterozygosity in other loci were also relatively high. A comparison of the two existing subpopulations, grey and black, at all the loci tested, including RAPD markers, characterized them as genetically distinct, although clearly related. The genetic distances between them were of the same order of magnitude as between distinct breeds. The results may be useful in defining short-term and long-term breeding policy within the breed and for further studies of associations with disease and other traits.

Animals↗
PubMed1998

Selective loss of BoLA class I determinants from the lymphocyte surface after acid treatment.

Acid treatment of bovine lymphocytes by a buffered solution of 0.263 m citric acid and 0.123 M Na2HPO4 at pH = 3.0, originally described for human and murine lymphocytes, selectively eliminated the antigenicity of MHC (BoLA) class I determinants also from bovine lymphocytes. The viability of acid-treated cell suspension was higher than 90%. The reactivity of acid-treated lymphocytes with BoLA class I typing alloantisera was lost in microcytotoxicity test, while their reactions with cross-reactive anti-HLA class II, anti-BoCD2 and BoCD5 monoclonal antibodies, and with antisera detecting two non-MHC lymphocyte alloantigenic specificities (BoLY w1 and R') remained unchanged in the microcytotoxicity and/or indirect immunofluorescence tests. The results thus show that this approach of modulating cell surface expression of MHC class I determinants may be used in cattle.

Animals↗
PubMed1998

BoLA DYA polymorphism in Czech cattle.

Polymorphism at the BoLA DYA locus was determined in two groups of Czech Black Pied cattle by PCR-RFLP detecting substitutions at nucleotide positions 112 and 219. Animals for this study were nonrandomly selected according to their health status in two BoLA-associated infections: bovine leukosis (n = 59) and Johne's disease (n = 36). A group of noninfected Czech Red Pied cows (n = 37) was used for comparison. The frequencies of DYA alleles and haplotypes were virtually identical in the two selected groups as well as in the infection-free animals. In contrast, distribution of BoLA DRB3.2 alleles differed considerably between the infected groups as expected based on the previously detected associations with BoLA. The results suggest that the polymorphism of the DYA unexpressed gene was not influenced by selecting animals for this study according to their health status.

Alleles↗
PubMed1994

A polymorphic monoclonal anti-BoLA class I antibody.

Cytotoxic monoclonal antibody IVA 44 was generated after the intraperitoneal immunization with peripheral blood mononuclear (PBM) cells and the boost by the intrasplenic inoculation of skin graft. The detected membrane antigen isolated by immunoprecipitation appears to be composed of two subunits characteristic for the MHC class I molecules. The antibody IVA 44 exhibited a different reactivity: it recognized the BoLA A14 (A8) specificity in animals typed in the Fifth BoLA workshop, while it reacted with all A8 positive animals including subtypes A14 and A15 in Czech and Slovak cattle. It is concluded that mAb IVA 44 might detect the broad subtype of A8 covering A14 and certain A15 split(s). The diverse A15 reactivity of this mAb in the workshop and our population could be explained by the different occurrence of A15 splits in both populations.

Animals↗
PubMed1992

Detection of T-lymphocytes in the peripheral blood and lymphoid tissues of cattle using a variant of the E-rosette test and monoclonal antibodies.

A simple and efficient variant of the E-rosette test based on addition of dextran to the incubation media is described. This variant 1) does not include B cells 2) involves some CD2+ null cells as described 3) is not inhibited by anti-CD5 antibody 4) correlates with CD2 expression 5) detects specific changes in the relative proportion of T-lymphocytes under the different conditions. In a group of calves the mean percentage of RFC in the peripheral blood lymphocytes was 53.59 +/- 8.70 and in cows there was 72.57 +/- 3.85. The proportion of RFC detected in bovine leukemia virus (BLV)--infected cows with lymphocytosis was less than one third of that in BLV--negative animals and vice versa in B (MHC class II+) lymphocytes.

Animals↗
PubMed1989

Absence of BoLA class I antigens on bovine spermatozoa.

Forty AI bulls were tested for BoLA class I antigens by means of eight specific polyclonal reagents. By means of immobilization and sperm penetration tests these antigens were not detected on sperm cells. Isoimmunization studies with the use of sperm as antigenic stimuli and insemination of frozen spermatozoa diluted in specific reagents did not prove the presence of BoLA class I antigens on bovine spermatozoa. The cytotoxic tests used in this investigation were not reliable.

Animals↗
PubMed1986

[Experimental and natural infection with the enzootic leukosis virus of cattle].

A trial was performed with heifers at the age of six to seven months. The animals were experimentally infected with the lymphocytes of a virus-productive donor. Infection was produced in all the nine cases, as demonstrated by means of the positive syncytial test. As indicated by the results of the trial, the antibodies to the enzootic bovine leucosis virus (BLV) were produced soon after experimental infection. A high sensitivity of the serum-neutralization test and the ELISA method was demonstrated in this connection: by these methods, the antibodies were identified already two to three weeks after experimental infection whereas by the immunodiffusion test they could be detected only after five weeks. Twenty-four animals were exposed to natural contact infection. Within 270 days of the trial, the disease after contact was recorded only in one heifer out of the four that were in close contact with the experimentally infected animals. In this case, as compared with experimental infection, the antibodies were produced much later--after 85 to 93 days. Leucosis was recorded in none of the remaining animals. The reasons why such a favourable result was obtained were the thorough disinfection of the stables after blood collections and the strict observance of the aseptic conditions. The results of experimental infection in three cows were identical with those obtained in young cattle. In the experimentally infected dairy cows, antibodies in milk were determined by the ELISA method. As found, in milk the antibodies to BLV appear two to three weeks later than they do in serum. The ELISA method of BLV antibody detection can be used for the identification of infected animals in herds where enzootic bovine leucosis occurs.

Animals↗
PubMed1986

[Immunoenzyme detection of enzootic bovine leukemia viruses (BLV) in cell cultures].

There is a description of the method of immunoenzymic test used for detection of enzootic bovine leukosis virus (BLV) on the cells of foetal lamb spleen (FLS) permanently producing BLV and on the lymphocytes of infected animals. In both cases (in FLS cells and lymphocytes) the presence of BLV was demonstrated by the immunoperoxidase test. Using the defined serums from the animals after experimental and natural infection, BLV was detected by the above-mentioned test in FLS cells in all cases of the use of positive serums with anti-BLV antibodies. The specificity of the antibodies was also demonstrated in this way. The presence of BLV was analogically detected in the lymphocytes of the infected animals where the infection time was precisely defined. The method of immunoperoxidase test on lymphocytes is recommended in indicated cases for the demonstration of the presence of BLV in infected animals.

Animals↗
PubMed1986

[Detection of enzootic bovine leukemia virus using the syncytium test].

BLV detection by the syncytial test was performed in 27 heifers experimentally and naturally infected by the enzootic bovine leukosis virus (BLV). The presence of BLV was demonstrated in 94.7% of the animals. The bovine foetal spleen cells (FBS) were found to be suitable for the syncytial test. Positive animals not reacting to infection by the production of anti-BLV antibodies were identified during the syncytial-test investigation. The importance of this finding for the programme of controlling enzootic bovine leukosis on farms is discussed. As suggested by the results, temporary occurrence of anti-BLV antibodies followed by their disappearance can be observed together with a negative result of the syncytial test in some circumstances. The discussion deals with the problems of the determination of anti-BLV antibodies in milk, and/or milk secretion, by the ELISA method.

Animals↗