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Biomedical subjects

S Lazary

Publications and source records attributed to S Lazary.

At least 37 records · Page 2Linked to original sources
PubMed1993

DNA sequence analysis of serologically detected ELA class II haplotypes at the equine DQ beta locus.

The genetic diversity at the ELA DQ beta locus was investigated using polymerase chain reaction and DNA sequencing. Based upon serological methods 16 class II homozygous animals were selected and their genomic DNA was used. A DQ beta gene from an equine cDNA library was also sequenced. Our methodology and the similarity between the genomic and the cDNA sequences suggest that the studied locus is expressed on equine lymphocytes. In the predicted amino acid sequence the most extensive variation is located at residues 56-60. The pattern of these five amino acids is strongly correlated to the serological ELA class II specificities (W13, W22, W23, Be200). The alleles corresponding to the W23 specificity are the most divergent among the equine DQ beta alleles and also from other mammalian DQ beta sequences.

Alleles↗
PubMed1993

Immune functions of veal calves fed low amounts of iron.

Immune functions were studied in male calves fed milk replacer (MR) containing 10 or 50 mg iron (Fe)/kg. Calves fed 10 mg Fe/kg MR developed marked hypoferremia and anemia, whereas serum-Fe and haemoglobin concentration of calves fed 50 mg Fe/kg MR were normal. Growth performance was reduced, while feed/gain ratio, incidence of infections (especially pneumonias), febrile body temperatures and antibiotic treatments were higher in calves fed 10 than 50 mg Fe/kg MR (p < 0.05). Whereas antibody production (to horse erythrocytes) and lymphocyte stimulation (by mitogens) were not significantly altered, cell-mediated immunity (measured as cutaneous delayed-type hypersensitivity reaction to dinitrofluoro-benzene), number of neutrophils with phagocytic capacity, activity of the Fe-containing enzyme myeloperoxidase, blood serum IgG concentration and the number and diameter of germinal centres as a measure of the number and production of B-cells in cervical superficial lymph nodes in calves fed 10 mg Fe/kg MR were reduced when compared with calves fed 50 mg Fe/kg MR (p < 0.05). In conclusion, severe Fe deficiency caused reduced growth performance, associated with and partly due to higher incidence of infections because of defective immune reactions.

Animals↗
PubMed1993

Serological and biochemical detection of B-cell antigens in goats.

The production of B-cell specific alloantisera by lymphocyte transfusion between class I matched, MLR positive goats is described. Furthermore, the usefulness of preceding IEF typing is demonstrated in the selection of immunization pairs. After suitable absorptions and cluster analysis the detected B-cell specific antigens were designated BeD1-BeD6. The specificity BeD3 could also be detected by two class II-specific murine anti-H2 monoclonal antibodies. IEF class II typing of 34 animals gave concordant results between the two techniques. One additional allelic variant could be detected by IEF typing. The detected products segregated in close linkage to the earlier described caprine class I antigens. One recombinant has been found in 78 offspring. The reactivity of cells in mixed lymphocyte cultures (MLC) was correlated with the compatibility of the test cells for their B-cell specific antigens. Three of the B-cell specific sera were characterized by immunoprecipitation. The precipitated antigens corresponded in molecular weight to MHC class II products as described in other species indicating that the here described caprine products are of class II nature.

Animals↗
PubMed1992

Exonic polymorphism vs intronic simple repeat hypervariability in MHC-DRB genes.

Gene products encoded by the major histocompatibility complex often exhibit a high degree of polymorphism. In humans the HLA-DR polymorphism is due to more than 50 alleles with varying exon 2 sequences. Each group of DRB alleles contains a certain form of the basic simple repeat motif (gt)n(ga)m in intron 2. Identical alleles can be differentiated on the basis of the hypervariable repeat. In this study focused on cattle (Bos taurus) we identified different Bota-DRB alleles in a limited survey by amplification via polymerase chain reaction and sequencing. In addition DRB exon 2 sequences were also obtained from eight additional hoofed animal species (seven horned artiodactyls and one pig) revealing artiodactyl-specific polymorphic and nonpolymorphic substitutions. In the genus Bos the intronic simple repeat variability was compared with exonic DRB polymorphism. As in humans all Bota-DRB exons were always associated with specifically organized basic simple repeat structures. Yet the extent of simple repeat variability was lower in cattle compared to humans. Selective breeding in the process of domestication might be responsible for the diminished intronic hypervariability. Nevertheless, the hypermutable simple repeat sequences have been preserved in the same position and with the same principal structure for at least 70 x 10(6) years of evolution. Unexpectedly, the rate of intronic simple repeat and exonic changes appear quite similar.

Alleles↗
PubMed1992

On the genetic basis of equine allergic diseases: II. Insect bite dermal hypersensitivity.

The horses studied were of the Swiss Warmblood breed and most were ELA-typed to assess a possible association of dermal hypersensitivity to insect bites with the major histocompatibility complex. Firstly, the occurrence of the condition was examined in 304 half-siblings sired by six stallions (A to F). Fourteen cases of dermal hypersensitivity were recognized and all were in the 153 offspring of Stallions C, E and F. Most animals of this group were also investigated for chronic hypersensitivity bronchitis: none of the sires displayed clinical signs of dermal hypersensitivity, but Stallions D, E and F were affected by chronic bronchitis. Among the animals investigated for both conditions only one horse showed coincidence of the two diseases as can be expected when the diseases are not correlated. The frequency of manifest dermal hypersensitivity and/or chronic hypersensitivity bronchitis varied in the half-sibling groups of individual sires. These findings suggest that the allergic conditions are independent entities. Secondly, the occurrence of dermal hypersensitivity was studied in three generations of horses at a stud at which Stallion C had exerted a particularly strong influence. A total of 302 animals, all born and raised at this stud, were surveyed over a period of 12 years. The descendants of Stallion C showed a significantly higher incidence (P less than 0.01) of dermal hypersensitivity (two daughters out of 19; eight second generation offspring out of 103; one third generation offspring out of 85) than did the controls of the same age classes but unrelated to Stallion C at the same stud (0 out of 95).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Characterization of BPV-like DNA in equine sarcoids.

The DNA from equine sarcoid samples from New York State and Switzerland was isolated and probed with bovine papillomavirus type 1 (BPV-1) to determine if BPV genomes were present. Twelve of 13 sarcoids from New York State and 17/20 sarcoids from Switzerland contained DNA that hybridized to the BPV-1 probe. Restriction enzyme analysis of the positive samples demonstrated restriction fragment profiles characteristic of BPV-1 in 22 sarcoids and restriction fragment profiles characteristic of bovine papillomavirus type 2 (BPV-2) in 7 sarcoids. In addition, three tissues histologically diagnosed as pyogranulomatous dermatitis, fibropapilloma, and fibrosarcoma contained BPV-like DNA. Tissues with BPV-1-like and BPV-2-like DNA contained an average of 285.7 (21 to 808) and 125.8 (2 to 762) BPV-like genomes per cell, respectively. Minor differences in the restriction fragment profiles of the BPV-like DNA and evidence for partial BPV-like genomes were found in some sarcoids. BPV-like DNA was not detected in lymphocyte DNA from sarcoid-affected horses. These results confirm previous observations and support the hypothesis that bovine papillomavirus, or a very similar virus, is linked to the cause of equine sarcoid.

Animals↗
PubMed1991

Production of alloantibodies against bovine B-lymphocyte antigens.

A series of alloimmunizations were carried out between BoLA class I antigen typed bulls, with the aim of generating class II specific reagents. Of the antisera produced, seven demonstrated exclusively B cell reactivity. Another 19 sera reacted with both T and B cells from some animals and with B cells only in other cases. Suitable buffy coat absorptions removed T cell reactivity from some sera and shortened broader reactivities in certain B cell specific sera. Typing of separated T and B cells from related and unrelated animals permitted clustering of the sera into four groups. These groups behave as allelic specificities. The class II nature of the recognized structures was strongly indicated by two further pieces of evidence. The presence or absence of particular B cell antigens correlated with reactivity of cells in one-way mixed lymphocyte cultures. In addition, a number of the B cell specific sera were characterized by immunoprecipitation of radiolabelled lymphocytes. The precipitated products corresponded in molecular weight to alpha and beta chains of MHC class II dimers, as has been found in this and other species.

Animals↗
PubMed1991

Distribution of leucocyte antigens in Icelandic horses affected with summer eczema compared to non-affected horses.

Three hundred and three horses, exported from Iceland to Norway, Sweden, Denmark, Switzerland or Germany were tested for their distribution of leucocyte antigens. One hundred and thirty-six horses were affected with summer eczema. The panel of sera recognised the internationally accepted ELA-specificities A 1 to A10, and the nine work shop specificities W 11 to W 15 and W 18 to W 21. Also, some local specificities, characterised in Switzerland (Be I, Be III, Be 8, Be 25, Be 26, Be 27), and two non major histocompatibility complex (MHC)-linked antigens (Ely 1:1, Ely 2) were included. Only one antigen, Be 8, gave a statistically significant difference in distribution between the two populations: Relative risk = 2.5, x2 = 10.11, corrected P less than 0.01.

Animals↗
PubMed1991

The genetic basis of equine allergic diseases. 1. Chronic hypersensitivity bronchitis.

The genetic influence on chronic hypersensitivity bronchitis (CB) was investigated in families at two studs and among half-siblings of three affected and three non-affected sires at several farms. The family members at the two studs were born and raised under the same conditions, whereas the half-siblings were kept individually under very different conditions and were exposed to various environmental factors. The diagnosis was based on long-term observations and multiple clinical examinations at each of the two studs. In the half-sibling group, the diagnosis was based on the individual history and on a thorough clinical examination. The history of all horses suggested the disease was caused by allergies (symptoms provoked by hay). Statistical analysis of the data in the first study showed that a greater percentage of off-spring of two affected parents developed CB (9 of 13) than those with only one affected parent (23 of 48) and those with two healthy parents (5 of 29). The distributions of the affected offspring in these three categories (none, one or both parents affected) differed significantly (P less than 0.005) from what would have been expected without a genetic effect. The tendency to develop the disease was inherited equally from dams or sires. In the second stud fewer animals (n = 42) were included in the study, but the results were similar. Parents without a history of CB produced off-spring with a low incidence of disease (1 of 16) compared with a higher incidence among descendants of one or two affected parents (10 of 26; P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Immunological reactions of pigs during long-term beta-adrenergic treatment.

Experiments were performed to determine the effects of the beta-adrenergic agonist Ro 16-8714 on the immune system of finishing pigs fed an adequate or a low-protein diet. Growth rate, nitrogen and fat retention, body composition as well as spleen weight were influenced by both beta-agonist and/or protein level, as expected. However, lymphocyte stimulation with Concanavalin A and phytohemagglutinine in vitro or in vivo antibody production against horse red blood cells were not changed by the beta-agonist in pigs fed sufficient or insufficient amounts of protein.

2-Hydroxyphenethylamine↗
PubMed1989

Biochemical evidence that equine leucocyte antigens W13, W22 and W23 are present on horse major histocompatibility complex class II molecules.

A number of horse alloantisera were characterized biochemically as being directed against MHC class I or class II antigens by immunoprecipitation of the corresponding antigens from lysates of biosynthetically radioactively labelled lymphocytes and determination of their molecular weights by SDS-PAGE and fluorography. Sera recognizing A2 and A3 specificities precipitated antigens of 44,000 Daltons molecular weight (class I heavy chain), whereas sera with specificities W13, W22 and W23 precipitated antigens corresponding to class II dimers (30,000 and 32,000 Daltons). Comparison with antigens precipitated from horse lymphocyte lysates using (cross-reacting) antibodies to human class I and class II MHC molecules confirmed the results obtained.

Animals↗
PubMed1988

Evidence for linkage between the caprine leucocyte antigen (CLA) system and susceptibility to CAE virus-induced arthritis in goats.

The distribution of caprine leucocyte antigens (CLA) in goats from four different breeds (n = 546) affected by caprine arthritis-encephalitis virus (CAEV)-induced arthritis were determined and compared breed for breed with those of infected but clinically healthy controls (n = 402). Differences in frequencies of some of the CLA specificities between the affected and control groups were found, but after correction of the ordinary P values for number of observed alleles, only the CLA Be7 specificity in the Saanen breed showed a significant deviation at the 0.05 probability level. Animals of the Saanen breed carrying this specificity are less prone to develop arthritis after CAE virus infection than goats lacking this specificity. Eleven groups (multiple-case families or halfsibling groups with at least two informative diseased offspring/group) were analyzed for manifestation of the disease and segregation of the parental haplotypes. The results of the maximum likelihood test of association (P less than 0.005) and the calculated high lod score value of 5.70 give evidence for linkage between the locus encoding the determined class I CLA alleles and a hypothetical locus (i) coding for genes responsible for arthritis resistance/susceptibility. The particular class I CLA allele associated with the disease susceptibility varied from family to family, however. These data provide the first evidence that CAE virus-induced arthritis in the goat is genetically influenced by the MHC system; they also suggest that susceptibility/resistance genes are not directly associated with the determined class I gene products but rather are in close genetic linkage.

Animals↗
PubMed1988

Association between equine leucocyte antigens (ELA) and equine sarcoid tumors in the population of Swedish halfbreds and some of their families.

The distribution of equine leucocyte antigens (ELA) in Swedish Halfbreds affected by sarcoid tumors was determined and compared with that of control horses of the same breed. ELA-haplotype A3W13 appeared more frequently in affected horses, resulting in a chi 2 value of 4.45 (P = 0.034) for A3 and 9.05 (P = 0.0026) for W13, respectively. The relative risk factor (RR) could be estimated to 2.13 and 3.00 for A3 and W13, respectively. The etiology fraction (EF) was calculated to 28% and 37% for A3 and W13, respectively. Thus, in the population of Swedish Halfbreds approximately 40% (at least) of the disease appeared to be associated with the genetic background of the affected horse. Family studies established that ELA are codominantly expressed and inherited as simple Mendelian traits and that sarcoids among offspring are significantly associated with one of the parental haplotypes (P = 0.00942). This parental haplotype does not always include A3W13. These results confirm and extend previous results from other breeds and strongly suggest the existence of a predisposition for sarcoids among horses, that is due to an autosomal, dominant, ELA-linked gene with incomplete penetrance. In extension, this indicates a multifactorial etiology of equine sarcoids (additional non-MHC gene(s) and/or environmental factors).

Animals↗
PubMed1988

Serological and genetic study of the ELA W21 specificity.

Investigations on the W21 specificity showed that this antigen is expressed on lymphocytes and platelets but not on erythrocytes. The molecule carrying the antigen W21 moves in the cell membrane independently from ELA locus A and B encoded antigens, as observed in 'lysostripping'. The W21 specificity occurs with very different gene frequencies in various breeds. In informative families it segregates together with defined gene products of the MHC region. The data suggest strongly that the W21 specificity belongs to the ELA system as a class I gene product, but is governed by a separate locus than the known locus A and locus B allelic series.

Absorption↗
PubMed1988

Restriction fragment length polymorphisms of horse class II MHC genes observed using various human alpha- and beta-chain cDNA probes.

Genomic DNA isolated from 20 horses was digested with up to six restriction endonucleases and subjected to southern blot hybridization analysis using various human class II alpha- and beta-chain cDNA probes. A high degree of restriction fragment length polymorphism (RFLP) was found for the DQ alpha, DP beta, DQ beta and DR beta probes, about 20 polymorphic bands being detected for each. DR alpha showed 2-4 polymorphic bands, whereas no evidence for DP alpha-like genes was found. A number of correlations of RFLPs with individual alloantisera were apparent.

Animals↗
PubMed1988

Joint Report of the Fifth International Workshop on Lymphocyte Alloantigens of the Horse, Baton Rouge, Louisiana, 31 October-1 November 1987.

Six laboratories participated in the Fifth International Workshop on Lymphocyte Alloantigens of the Horse, testing 132 alloantisera against lymphocytes of 880 horses chosen to represent different families and breeds. Most of the alloantisera were produced by lymphocyte immunization between horses matched at the ELA-A locus. All horses were also tested with antisera contributed to the workshop by participating laboratories which identified ELA specificities A1-A10 and W12-W21. Previously identified workshop specificities ELA-W14, W15 and W19 were accepted as products of the ELA-A locus based on family and population studies by the workshop. Their designations were changed to ELA-A14, ELA-A15 and ELA-A19, respectively. Two new specificities were identified, namely ELA-W22 (W22) and ELA-W23 (W23). Population and family studies indicated that W22 and W23 as well as W13 are products of an ELA locus other than ELA-A. The presence of these specificities was correlated with the presence of certain ELA-A locus specificities, e.g. W13 with A3, W22 with A2 and W23 with A5. However, the association was not complete and W13, W22 and W23 also segregated with other ELA-A specificities in some families. Evidence for recombination was found between the ELA-A locus and the locus or loci encoding these specificities resulting in seven recombinant haplotypes found among the data presented in this workshop. Further studies are required for definitive assignment of the specificities to a class I or class II locus.

Animals↗