Blood group association with severity and speed of the halothane reaction.

The second generation (n = 227) of British Landrace pigs from selected halothane-positive parents (36 litters) were blood-typed for the S(A-O), H and Phi loci and subjected to four 5-minute halothane tests at 21, 35, 49 and 63 days of age. Cumulative scores based on severity and speed of reaction were analysed in relation to single-locus blood group genotypes and linkage group sequences at two and three loci. A highly significant negative correlation (r = -0.79) was found between severity and speed of reaction. Significant differences occurred between blood group genotypes and linkage groups in both severity and speed of reaction. Genotypes S s/s, H a/a or H a/- and Phi B/B and linkage groups involving these three types had the highest cumulative reaction score and the fastest reaction time, whereas genotypes Phi A/B, S S/S or S S/s and H a/cd and linkage groups with these types had the lowest and slowest reaction scores. Some differences between genotypes and linkage groups were attributed to phenotypically halothane-positive parents and offspring being genotypically Hal N/n. These effects could result from linkage with heterozygous types such as H a/cd and S S/s. The possible role of the H cd allele acting as a genetic marker for a suppressor gene to the halothane reaction is discussed.

A reagin-like antibody in horse serum. II. Anti-human IgE induced reversed cutaneous anaphylaxis-like responses in horse skin.

Fc specific anti-human IgE serum induced prolonged reversed cutaneous anaphylaxis (RCA)-like reactions in horse skin. Morphologically and histologically, these reactions resembled passively induced late cutaneous anaphylaxis responses in human skin, but differed from reversed passive Arthus responses induced in horse skin using anti-horse IgG serum. The induction of RCA-like responses in horse skin by anti-human IgE indicates shared Fc antigenic determinants on human IgE and a horse homocytotropic or reagin-like antibody.

A reagin-like antibody in horse serum: 1. Occurrence and some biological properties.

The demonstration of a reagin-like antibody against Culicoides pulicaris extract in the serum of horses and ponies affected with recurrent seasonal dermatitis (sweet itch) is reported. This antibody can confer Prauznitz-Küstner (P-K) sensitivity on homologous skin for up to 5 days and, like human IgE, is thermolabile and susceptible to 2-mercaptoethanol reduction. It is eluted on diethylaminoethyl dextran-52 anion exchange chromatography independently of IgG, IgG(T) and IgM, and its elution characteristics indicate similarity in net molecular charge to human IgE. The P-K response observed in horse skin is biphasic, and is morphologically similar to the late cutaneous anaphylactic response in man. Both phases of the P-K response are dependent upon the reagin-like antibody, although other serum factors appear involved in the delayed phase of the response.

Causes of death and sex differences in survival times of pigs with untreated hereditary lymphosarcoma (leukemia).

The survival times from birth of 39 entire male Large White pigs with hereditary lymphosarcoma (L/S) were significantly shorter than those of 76 affected females. The survival times of 19 male castrates were for the most part intermediate between those for entire males and females. Analysis of the cause of death revealed that pigs with L/S (L/S-P) were more likely than pigs without L/S to die from colibacillosis, but this disease showed to sex predisposition. In uncomplicated deaths from L/S, weights of splanchnic lymph nodes, spleen, and thymus were greatest in females. The cell-mediated and humoral antibody responses of L/S-P were significantly poorer against 2,4-dinitrofluorobenzene (DNFB) and sheep red blood cells, poorer against skin homografts, but better against bovine serum albumin than those of healthy littermates. Healthy females had stronger DNFB reactions than did healthy males or castrates. Castrated L/S-P responded to DNFB better than did females and significantly better than did entire males.

Linkage studies between the halothane (Hal), phosphohexose isomerase (Phi) and the S(A-O) and H red blood cell loci of Pietrain/Hampshire and Landrace pigs.

Frequency of blood group factors at the A-O and H loci were markedly altered within halothane positive (HP) and halothane negative (HN) composite synthetic Pietrain/Hampshire lines (PTH) over four generations of selection. Linkage studies on the litters from 45 double backcross and 20 mixed and intercross matings, involving the S(A-O), H, Phi and Hal loci, were made in the PTH line and halothane positive and negative selected British Landrace lines. Crossing-over frequencies of 0.05 +/- 0.04, 0.05 +/- 0.03 and 0.1 +/- 0.03 were established between Phi and Hal, H and Hal, and Phi and H respectively. An unequal crossing-over frequency between Phi and H was found when the alleles Ha and Hcd were compared. The difference in recombination frequency between the Ha and Hcd alleles amounted to 0.04 to 0.06. No cross-overs were observed between the S(A-O) and Phi, H or Hal loci in 15 families studied. The position of the S locus in relation to the other loci could not be established, but statistical evidence of association favours a haplotype sequence of Phi-Hal-S-H.