A comparative study of major histocompatibility complex antigens in east African and European cattle breeds.

An account is given of the serologically defined class I specificities encoded by the bovine MHC (expressed as the BoLA system) in two populations of African cattle and in European breeds. The BoLA typing was performed using alloantisera raised against tissue antigens of both European and African breeds of cattle. All of the specificities agreed in the first two international BoLA workshops were found in the African cattle, although there were significant differences in the frequency of some specificities between the African and European animals.

Relationship between the bovine major histocompatibility complex (BoLA), erythrocyte markers and susceptibility to mastitis in Icelandic cattle.

Milk and blood samples were obtained from three Icelandic dairy herds. The herds were monitored regularly for mastitis incidence. Cell counts, adenosine triphosphate (ATP) and antitrypsin levels of the milk samples were recorded.

Characterization of class I bovine lymphocyte antigens (BoLA) by one-dimensional isoelectrofocusing.

BoLA class I antigens were characterized in a group of British and Dutch Friesian cattle by one-dimensional isoelectric focusing (1D-IEF) and the results compared with serology using alloantisera and microcytotoxicity. For IEF analysis, non-stimulated peripheral blood mononuclear cells (PBM) were metabolically labelled with 35S methionine, detergent lysates were prepared and MHC molecules precipitated with the monoclonal antibodies (mAbs) W6/32 or B1.1G6.

Activation of the xylDLEGF promoter of the TOL toluene-xylene degradation pathway by overproduction of the xylS regulatory gene product.

The xylS regulatory gene of the Pseudomonas putida TOL plasmid (pWWO) has been cloned under the transcriptional control of the Escherichia coli tac promoter in a broad-host-range controlled-expression vector. Induction with isopropylthiogalactoside allowed overproduction and characterization of the xylS product by specific interaction with the TOL meta-cleavage pathway operator-promoter region (OP2) in vivo in E. coli.

Detection of microalbuminuria in diabetic patients using a simple latex agglutination test.

The adaptation of an immunoturbidimetric assay to quantitatively measure urinary albumin is described and this was used to evaluate a commercial latex agglutination slide test, Albuscreen, with a sensitivity of 25 mg/l. Excellent agreement was observed between the two methods, and in clinical studies an acceptable classification of patients was made using Albuscreen, an albumin: creatinine ratio of less than or equal to 2.5 being used to indicate possible microalbuminuria.

Studies on the major histocompatibility complex of indigenous cattle in the Ivory Coast.

The MHC (BoLA) type has been determined for cattle from three breeds in West Africa. Seventy Baoule, 50 N'Dama and 30 Zebu cattle from the centre and north of the Ivory Coast were tested. Lymphocytes from these cattle were tested in a lymphocytotoxicity test with alloantisera detecting all of the internationally recognised BoLA sera.

Bovine alloreactive cytotoxic cells generated in vitro detect BoLA w6 subgroups.

Alloreactive cytotoxic T cells (CTL) were generated in mixed lymphocyte culture against cells bearing subgroups of BoLA w6, as well as in BoLA w4, w10 and w16. Primary cultures were restimulated at weekly intervals with irradiated stimulator cells and tested in a 51Cr-release assay with target cells derived from Theileria annulata-infected cell lines. Generation of CTL was accelerated in animals that had been previously primed in vivo by skin grafting.

Use of bovine lymphocyte antigens in diagnosis of parentage.

Lymphocyte antigens controlled by alleles at the BoLA-A locus were used to indicate which of two bulls could be eliminated as the sire in 18 cases of disputed parentage. The use of bovine lymphocyte antigens (BoLA) significantly increased the exclusion probability over that of the standard red cell and electrophoretic techniques.

Genetic, functional and sequence analysis of the xylR and xylS regulatory genes of the TOL plasmid pWW0.

Mutant derivatives of a plasmid, pCF20, which carries the XhoI-D fragment of the TOL plasmid pWW0 have been isolated using Tn5 transposon mutagenesis. Insertion mutations of the xylR and xylS regulatory genes of the catabolic pathway have been isolated and characterized and their ability to induce catechol 2,3-oxygenase activity determined. Analysis of the insertion mutants and also segments of the XhoI-D fragment cloned into plasmid pUC8 in maxicells has identified a 68 kDa polypeptide product encoded by the xylR gene.

Possible association of antibody responses to human serum albumin and (T,G)-A--L with the bovine major histocompatibility complex (BoLA).

Antibody responses to human serum albumin (HSA) and (T,G)-A--L were determined in 130 young bulls in Norway and the BoLA types of the bulls were defined. Significant associations of some BoLA antigens with immune responsiveness were shown, indicating the likely existence of an immune response (Ir) region linked to the BoLA class I antigens. High response to HSA seems to be a dominant trait.

Selenium depletion and its correction in a child with homocystinuria.

A child of 10 months with proven homocystinuria was found to be selenium depleted and we report the serial monitoring of replacement therapy. Selenium, as an enriched yeast preparation, equivalent to 50 mug on alternate days was required for maintenance. Indices of selenium status returned to normal in varying times.

Bovine alloreactive cytotoxic cells generated in vitro: target specificity in relation to BoLA phenotype.

Cytotoxic cells of bovine origin were generated in primary MLC using stimulator cells of BoLA w8/w11 phenotype. Bovine lymphoblasts transformed by the protozoan parasite Theileria parva parva acted as target cells in studies of the specificity of cytotoxicity. When responder cells in MLC did not share w8 or w11 with stimulator cells, cytotoxicity was evident with all targets bearing w8 or w11, or both, and was almost entirely restricted to these products of the BoLA-A locus.

Cross reaction of monoclonal antibodies to human MHC class I and class II products with bovine lymphocyte subpopulations.

Peripheral blood lymphocytes (PBL) from cattle have been separated into T & B cell subpopulations using a panning technique. These T and B cell preparations have then been tested by direct and indirect complement mediated cytotoxicity tests with a series of monoclonal antibodies (Moabs) reacting with HLA class I and class II products. The anti-class I monoclonals were monomorphic or non-reactive and where reactive killed both B and T cells.

A histocompatibility barrier to immunization against East Coast fever using Theileria parva-infected lymphoblastoid cell lines.

Histocompatibility may be a barrier to the infection of cattle when Theileria parva parva-infected tissues or in vitro cultured macroschizont-infected lymphoblastoid cell lines are used for immunization. By inoculating 10(3) and 10(5) infected cells into autologous recipients infection was achieved and immunity engendered. Cell lines inoculated into BoLA matched recipients did not produce patent infections but some recipients developed antibodies to the parasite and 3/5 were immune to challenge.

Observed activities of serum creatine kinase: total and B subunit activity and other enzymes in young persons abusing solvents.

Serum enzymes (aspartate transaminase, alanine transaminase, alkaline phosphatase (ALP), gamma-glutamyltransferase, and creatine kinase (CK] were measured in 296 young persons who admitted to recent inhalation of solvents, usually toluene based glues. In general, results fell within expected adult reference ranges except for ALP and CK. About 60% of subjects had CK activities above the upper reference limit and these activities were investigated in terms of their isoenzyme composition.

A method for freezing bovine lymphocytes.

A simple two-stage technique for preserving bovine lymphocytes is described. Lymphocytes from animals chosen at random were used. The experiments indicate that the optimum temperature for freezing and the optimum concentration of dimethylsulphoxide (DMSO) as cryoprotectant were in the range -29 degrees C to -31 degrees C and 17.

Culling and wastage in dairy cows in East Anglia.

A culling survey in 80 Friesian dairy herds in East Anglia over four years investigated the age at, and reasons for, disposal or death. Failure to conceive was the most important reason except in very old animals. Low production was the second most common reason, culling being particularly heavy in the first two lactations.

Cell-mediated cytotoxicity in Theileria annulata infection of cattle with evidence for BoLA restriction.

Recovery of calves from tropical theileriosis was accompanied by the disappearance of macroschizonts from lymph nodes and the appearance of cytotoxic cells in the blood and lymph nodes. Acute, fatal disease was associated with incremental parasitosis and parasitaemia and, in general, an absence of detectable cytotoxic cells in the blood or lymph nodes. After recovery from infection, calves were resistant to challenge.