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The equine leucocyte antigen (ELA) types and the clinical diagnosis for equine sarcoid and summer dermatitis were evaluated in 2026 horses representing five breeds. Data were analysed in unrelated animals and in family material. In the case of equine sarcoid, a strong association was observed between the ELA class II DW13 antigen and its effect on Swiss (cP < 0·001), French (cP < 0·0001) and Irish (cP < 0·01) Warmblood horses. The class I antigen A3 occurred more frequently in sarcoid-affected French horses (cP < 0·001). These results confirm our earlier findings (Gerber et al. 1988). Among Freiberger horses, which lack the ELA DW13 and A3 specificities, a breed-specific class I antigen, ABe108, displayed an increased frequency (cP < 0·05) in the affected group. Among Arabian horses, a tendency for increased frequency of the A1 antigen was observed in the affected animals, but the number of affected horses is too small for statistical significance. The Mendelian segregation in diseased half-siblings by ELA DW13 heterozygous stallions showed a strong association (P < 0·0001) between the inherited DW13 antigen and susceptibility to the sarcoid effect. In the case of summer dermatitis, previously published data (Marti et al. 1992) have been extended. The ELA types in four multiple-case families, founded by the same stallion, were analysed for an association with the effect of sarcoid. Eight out of nine ELA-typed affected offspring inherited the paternal haplotype A15, DW23 in contrast to nonaffected offspring where three out of 12 displayed these antigens (P < 0·005). Moreover, the ELA haplotypes of 11 out of 12 informative affected half-siblings sired by another stallion inherited the paternal haplotype A3, W12, DW23 (P < 0·05). Our findings demonstrate statistically significant associations between certain ELA antigens and two equine diseases. It is still unknown if the major histocompatibility complex (MHC) molecules themselves or another linked gene(s) play a role in the pathogenesis of these conditions. 相似文献
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The genetic diversity at the ELA DQβ 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 DQβ gene from an equine cDNA library was also sequenced. Our methology 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 DQβ alleles and also from other mammalian DQβ sequences. 相似文献
4.
Abstract: The enzymatic hydrolysis of UDP-galactose in rat and calf brain was studied. The hydrolysis occurs in two steps: The first is the conversion of UDP-galactose to galactose-1-phosphate catalyzed by nucleotide pyrophosphatase (EC 3.6.1.9), and the second is the conversion of the latter to free galactose by alkaline phosphatase (EC 3.1.3.1). The overall conversion has a pH optimum of 9.0, but there is considerable activity at pH 7.4, which is the optimum for UDP-galactose:ceramide galactosyltransferase in the synthesis of cerebrosides. Preparations from cytosol from calf brain cerebellum or stem that were enriched in UDP-galactose hydrolytic activity inhibit cerebroside synthesis under conditions optimal for the synthesis. Microsome-rich and nuclear debris fractions contain the highest apparent specific activity among the subcellular fractions studied. Hydrolysis of UDP-galactose occurs in all areas of brain, brainstem having the highest activity. The apparent specific activity in jimpy mouse brain homogenate is nearly twice as high as in the control brain homogenate. 相似文献
5.
G. B. Gerber 《Radiation and environmental biophysics》1982,20(4):235-243
Summary Interaction from several agents, i.e., a greater or smaller effects than expected from the sum of the individual effects can be of essentially two types: a) The agents could act in paralell on the same target, and a term depending on the doses of the agents involved would have to be added to the individual dose effect relationships (parergic interaction). b) The agents could act at different points in the chain of events leading to the observed effect, and the action of the second agent, the promotor, would be, at least in part, contingent on the action of the first inducer agent so that the dose effect relationships are linked in a multiplicative manner (metergic interaction). The dose effect surfaces for interaction depend on the type of dose effect relationship of the individual agents. Formulas are given for the general cases and are exemplified in graphs. Typical isobolic diagrams are also illustrated. These formulas may be adapted to experimental data by means of non-linear regression or maximum-likelihood analysis. 相似文献
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The 13C NMR spectra of geosmin, selina-4(14),7(11)-diene-99-ol and two dihydroeudesmol isomers have been obtained and the individual resonances assigned. Several different empirical correlations developed by others have been combined in simple calculations to predict chemical shift values for sesquiterpenols of the eudesmane group. 相似文献
8.
Novel hybrid maturases in unstable pseudorevertants of maturaseless mutants of yeast mitochondrial DNA. 总被引:5,自引:1,他引:4
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Unstable pseudorevertants of mitochondrial mutants of Saccharomyces cerevisiae lacking the maturase function encoded by the fourth intron of the cytochrome b gene (bI4) were isolated. They were found to be heteroplasmic cells owing their regained ability to respire (and grow on glycerol medium) to the presence of a rearranged (rho-) mtDNA that contains an in-frame fusion of the reading frames of the group I introns bI4 and intron 4 alpha of the coxl gene encoding subunit I of cytochrome c oxidase (aI4 alpha). The products of those gene fusions suppress the bI4 maturase deficiency still present in those heteroplasmic cells. Similar heteroplasmic pseudorevertants of a group II maturaseless mutant of the first intron of the coxI gene were characterized; they result from partial deletion of the coxI gene that fuses the reading frames of introns 1 and 2. These heteroplasms provide independent support for the existence of RNA maturases encoded by group I and group II introns. Also, since the petite/mit- heteroplasms arise spontaneously at very high frequencies they provide a system that can be used to obtain mutants unable to form or maintain heteroplasmic cells. 相似文献
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The two parameters of the hyperbolic tangent equation, Pm and, were estimated from in situ vertical profiles of primary productionusing mesocosm data along a nutrient gradient. The parameters,derived from 4-h (around noon) 14C incubations, were used togetherwith the photosynthesis-light curve and hourly solar radiationdata to calculate daily primary production rates (Pd). Approximately40% of the daily production occurred in the 4 h around noon.Considering parameter uncertainty, there was no indication ofan increase in variation in production with increased nutrientloading, nor did biomass-specific P-I parameters increase. Annualproduction ranged from 82 to 901 g C m2 year1and was highest in the highest nutrient treatment tank. Dailyproductivity ranged from 0.02 to 9.1 g C m2 day1and was significantly correlated, in all treatments, with acomposite parameter BI0/k (where B is phytoplankton biomass;I0 is daily radiation and k is the extinction coefficient).Linear regressions of Pd against BI0/k indicated that much ofthe variability (86%) in productivity was explained by lightavailability and phytoplankton biomass. Two approaches for predictingproductivity were compared: (i) predicting production directlyfrom environmental variables (i.e. BI0/k) and (ii) predictingthe parameters of the P-I curve from environmental variablesand using these to calculate daily production. 相似文献