The qualitative assessment of glycosaminoglycans in the canine intervertebral disc using a critical electrolyte concentration staining technique.

Through the use of a critical electrolyte concentration staining technique, the glycosaminoglycans (GAGs) in the nucleus pulposus region of the canine intervertebral disc were arbitrarily identified as "hyaluronic acid", chondroitin sulphate and keratan sulphate. Approximate estimates of GAG concentration could be qualitatively deduced by determining the appropriate GAG "ALCIANOPHILIC INDEX". This index was considered to be an effective qualitative adjunct to chemical quantitation of GAGs in the intervertebral disc.     

The "barker" (neonatal respiratory distress) syndrome in the pig: its occurrence in the field.

A new syndrome, characterised by acute respiratory distress and by abnormalities of the skin, hair and thyroid, was the apparent cause of neonatal death in 35 (24 per cent) of 146 piglets sired by a large white boar in four small commercial pig units. The syndrome appears to be of genetic origin, inherited as an autosomal recessive trait. Its similarities with the respiratory distress syndrome (RDS) of the newborn infant and the "barker" syndrome of the newborn foal are discussed.     

Biochemical genetics of oxidative resistance to diazinon in the house fly

The genetics and biochemistry of oxidative resistance to diazinon were investigated in a diazinon-resistant strain of the house fly, Musca domestica L. The resistant strain was crossed with a multimarker susceptible strain and substrains containing portions of the resistant strain genome were prepared. Resistance, microsomal oxidase, and cytochrome P-450 spectral characteristics were then compared in the different strains. The major gene for resistance to diazinon is semidominant and is located on chromosome II, 13 crossing over units from the recessive mutant stubby wing. Additional resistance genes occur on chromosome II and on other chromosomes as well. Resistance to diazinon was introduced into a susceptible mutant-marked strain via genetic crossing over. Increases in parathion oxidase, total and P-450-specific N- and O-demethylase activity, and resistant strain type I binding spectrum were introduced along with resistance, indicating genes controlling these parameters and resistance are either identical or closely linked. No increase in activity of cytochrome P-450 itself was introduced into the mutant strain. Additional genes controlling the amount of cytochrome P-450 and several spectral changes characteristic of the resistant strains are apparently controlled by genes located at different loci on chromosome II. Resistance factors on other chromosomes are also present, but were not characterized.     

Identification of immunoglobulins associated with complement fixation, agglutination, and low pH buffered antigen tests for brucellosis.

Serums from infected cattle, cattle with persistent postvaccinal antibody, and serologically "positive" noninfected cattle were fractionated into major immunoglobulin classes by diethylaminoethyl (DEAE)-cellulose chromatography and by sucrose density gradient centrifugation. Each fraction was assayed for anti-Brucella activity by standard tube-agglutination test (STT), buffered tube-agglutination test (BTT), and complement-fixation test (CF). In the serums from experimentally infected cattle, anti-Brucella antibody could be found by all tests in 6 DEAE fractions and in slow, fast, and sediment regions of the density gradient. Serums from cattle with persistent postvaccinal titers had STT activity in all 6 DEAE fractions, BTT activity in 5 fractions, and CF activity in only 1 fraction. The STT and BTT activities were found in the slow and the sediment regions of the gradient, whereas the CF activity was found only in the slow region. Serums from a chronically infected animal had STT and BTT activities in 2 DEAE fractions and CF activity in only 1. The STT, BTT, and CF activities were found in the slow and the sediment regions of the gradient. The principal antibody in serums from noninfected cattle was immunoglobulin M, which had all of the CF activity and most of the STT and BTT activities. Low levels of STT and BTT activities were found in 3 other DEAE fractions. Only STT and BTT activities were found in the fast and the sediment regions of the gradient.     

Agammaglobulinemia in a horse with evidence of functional T lymphocytes.

Agammaglobulinemia was diagnosed in a 1-year-old Thoroughbred horse on the basis of the following observations: (1) absence of serum immunoglobulins M, A, and G(T); (2) small amounts of serum immunoglobulin G (16 mg/100 ml); (3) absence of specific antibody in the serum of the horse following immunization and challenge exposure to 2 antigens; (4) absence of plasma cells, primary follicles, and germinal centers in a lymph node removed after antigenic stimulation; (5) absence of "natural" serum antibodies to rabbit-erythrocytes which were easily detectable in age-matched control horse serums; and (6) increased susceptibility to infections. There was evidence of functional cell-mediated immunity which included a skin response to injected phytolectins, skin response to antigen challenge following sensitization, and in vitro proliferative response of lymph node cells to phytohemagglutinin. An intact cell-mediated immune response was also supported by the observation that the horse lived to 17 months of age without antibody production, whereas horses with an absence of both antibody production and cell-mediated immunity (combined immunodeficiency) die by 4 months of age without immunologic intervention. The known features of agammaglobulinemia in this horse are similar to those in sex-linked agammaglobulinemia in persons and are unique among the immunodeficiences described in other animals.     

The substitution of lysine supplemented high protein wheat for protein feeds during the rearing and laying periods of hens. 8. Nitrogen excretion and true amino acid digestibility as an effect of various lysine levels and successive laying periods]

Digestibility trials were performed with laying hens receiving 3 types of rations containing equal proportions of the same dietary components. The percentage of high-protein wheat in these rations was 74%. Ration I was supplemented with 0.12% lysine while 0.06% lysine was added to ration II; ration III remained unsupplemented. The crude protein content of rations 1 to 3 was 16.1%, 16.5% and 16.6%, respectively. The corresponding lysine percentages were 0.66, 0.62 and 0.56. Studies were made to investigate the influence of different lysine levels on the rate of N excretion and various amino acid data. These studies were carried out during two successive laying periods. Only random differences between the data for urinary N excretion and N balances per kg liveweight were obtained in the two laying periods and for the different lysine levels. The true lysine digestibility was significantly lower in the poor-lysine ration as compared with the ration with 0.66% lysine. Moreover, the absorptive capacity for thio-amino acids is influenced by the lysine level of the ration. The proportion of lysine contained in faecal crude protein increased with the decreasing lysine content of the ration. Similarly, the total number of amino acids present in faecal crude protein increased with the declining supply of lysine. These findings suggest that relatively more NPN compounds are excreted in the faeces if adequate amounts of amino acids are supplied rather than when one amino acid is deficient.     

Excessive oral administration of iron to sheep. 1. Digestibility of rations, results of fattening and carcass yields]

4 digestibility trials (4 male sheep per group) and 2 growth trials were carried out with 24 (V 1) and 32 (V 2) fattening lambs to investigate the effect of abundant oral Fe doses on the digestibility of crude nutrients in a ration of barley + dried green feed and on the results of fattening and carcass yields. Fe supplementation (less than 1400 mg per sheep/day) did not significantly change the digestibility coefficients of crude nutrients. Increasing Fe levels in the concentrates decreased the rates of liveweight increase and food consumption in both growth trials. Well-established statistical evidence was provided for the decline in absolute carcass yields resulting from the lower weight of the lambs at the end of the fattening period after Fe supplementation.     

Changes in the ultrastructure of cardiac muscle in steers deprived of copper.

Young Friesian steers were fed for nine months on copper supplemented or depleted diets. Immediately after they had been killed, tissues were taken from the myocardium for examination by electron microscopy. Copper deficiency was associated with extensive changes in myofibrillar and mitochondrial morphology and distribution. It is suggested that the ultra-structural changes in the myocardium were specifically attributable to copper deficiency, the most likely underlying biochemical defect being lost of cytochrome oxidase activity.