The relationships of birth weight, preweaning gain and postweaning gain with the bovine major histocompatibility system

A total of 739 cattle from nine breeds maintained at the Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska were tested for 42 class I antigens of the bovine major histocompatibility system (BoLA). Each antigen appears to be the product of a distinct co-dominant allele of the BoLA-A locus. The number of antigens present in each breed ranged from a minimum of 10 in Hereford to a maximum of 21 in Charolais cattle. There were large differences among breeds in the frequencies of antigens. The effect of each antigen on birth weight, preweaning weight gain and postweaning weight gain was estimated in a gene substitution model. Each breed was analyzed separately. There were significant effects of some BoLA antigens on birth weight, preweaning weight gain and postweaning weight gain, which is consistent with previous reports showing associations between the major histocompatibility system and growth parameters in mice, rats and pigs. However, further research is necessary to confirm these findings and to determine the biological mechanisms underlying these associations.     

Effect of pelleting and beta-glucanase supplementation on the ileal and fecal digestibility of a barley-based diet in the pig

The influences of pelleting and beta-glucanase supplementation on the digestibility of dietary components in a barley-based diet were investigated in pigs fitted with cannulas in the terminal ileum. The diet contained 49.0% starch, 18.9% crude protein and 14.8% dietary fiber, with arabinoxylans (4.9%), mixed-linked beta-glucans (3.4%) and cellulose (3.3%) as the main fiber components. Pelleting increased mixed-linked beta-glucan solubility from 45 to 62%. Neither treatment influenced the ileal or fecal apparent digestibilities of dry matter (64 and 80%, respectively), energy (62 and 79%), crude protein (53 and 75%), crude fat (26 and 27%) or dietary fiber (58 and 72%). However, pelleting increased (P less than .01) the pre-ileal apparent digestibility of starch from 91.5 to 95.3% and decreased (P less than .03) that of ash from -10 to -23%, while increasing (P less than .005) the fecal apparent digestibility of starch from 98.6 to 99.7%. The solubility of mixed-linked beta-glucans in ileal digesta was lower (P less than .001) in pelleted (26%) than in unpelleted (58%) diets. beta-glucanase supplementation also increased (P less than .05) the ileal apparent digestibility of starch, from 92.6 to 94.3%, and of mixed-linked beta-glucans, from 95.7 to 97.1%. Significant between-pig differences in the apparent digestibility of dietary components were observed. In conclusion, treatments that disrupt the endosperm cell walls in barley can increase the proportion of the diet digested prior to the large intestine.     

Immunocytochemical study of tissues from clinically normal dogs and of neoplasms, using keratin monoclonal antibodies.

Three commonly used keratin monoclonal antibodies (MAB)--AE1:AE3, CAM 5.2, and MAK-6--were compared with routinely used cytokeratin antibody. The expression of these antibodies was analyzed in several tissues obtained from clinically normal dogs and in a variety of neoplasms from dogs. Using appropriate enzymatic digestion, paraffin-embedded tissues processed in routine manner retained their typical keratin expression. Differentiated and poorly differentiated epithelial neoplasms, lymphomas, and melanomas were studied by use of the avidin-biotin-peroxidase technique. All 4 of the aforementioned antibodies had similar staining profiles. Of 3 anaplastic carcinomas, 2 had positive reaction to all 4 antibodies. All lymphomas, plasma cell tumors, and amelanotic melanomas had negative reaction to MAK-6, CAM 5.2, AE1:AE3, and cytokeratin MAB. Three basal cell epitheliomas had positive reaction to all 4 antibodies, whereas 1 basal cell tumor with a solid pattern had negative staining reaction. Two carcinoids had negative reaction to all markers and 1 of 2 malignant chemodectomas and 1 transitional cell carcinoma had staining reaction to only AE1:AE3 MAB. Comparing the 4 antibodies, use of AE1:AE3 MAB produced the strongest staining intensity followed by cytokeratin, MAK-6, and CAM 5.2 MAB. All 4 antibodies had low background staining. In conclusion, AE1:AE3 and MAK-6 MAB are as useful as cytokeratin MAB for identification of poorly differentiated epithelial neoplasms in dogs and cats.     

Changes in the MHC Class II+ Dendritic Cell Population of Ovine Skin In Response to Orf Virus Infection

Abstract— Class II+ dendritic cells were widely distributed throughout normal ovine skin in two main locations: a) in or immediately adjacent to the epidermis and epidermal appendages and b) in the vicinity of the blood vessels. They are unlikely to represent a homogeneous population particularly since Langerhans cells, which previously have been found throughout the epidermal appendages, were located only in the epidermis using acetylcholinesterase staining. Following infection with orf virus, a dense mass of closely associated class II+ dendritic cells develops in the exposed necrotising dermis, adjacent to infected hair follicles and under infected degenerating epidermis. These cells interact and appear to form a barrier to invasion, a framework for immune defence and a template for subsequent epidermal repair; they seem to provide the basis of a highly integrated local dermal defence system. Résumé— Des cellules dendritiques de classe II+étaient largement réparties dans la peau ovine normale dans deux principales zones a) dans l'épiderme et les annexes épidermiques ou dans leur voisnage immédiat b) au voisinage des vaisseaux sanguins. Il est peu probable qu'elles représentant une population homogène particulièrement parce que les cellules de Langerhaps, qui ont été découvertes précédemment dans l'ensemble des annexes épidermiques, furent localisées seulement dans l'épiderme en utilisant une coloration à l'acétylcholinesterase. Après une infection par le virus de l'ecthyma, il se forme une masse dense de cellules dendritiques de classe II+étroitement associées, dans le derme nécrotique atteint, adjacente aux follicules pileux infectés et sous l'épiderme dégénératif infecté. Ces cellules interagissent et apparaissent former une barrière à l'invasion, un cadre pour les défenses immunitaires et un patron pour la réparation épidermique ultérieure; elles semblent fournir les bases d'un système de défense dermique local hautement intégré. Zusammenfassung— Klasse II+-Dendritenzellen waren in der gesamten Haut von normalen Schafen in vorwiegend zwei Bereichen verbreitet: a) in oder unmittelbar neben der Epidermis und der epidermalen Anhangsgebiete und b) in dor Nähe dar Blutgefäße. Sie stellen wahrscheinlich keine homogène Population dar, da die Langerhanszellen, die früher übarall in den epidermalen Anhangsgebilden nachgewiesen wurden, bei Acetylcholinesterase-Färbung nur in der Epidermis zu finden waren. Nach einer Orf-Virus-Infektion formiert sich eine dichte Masse aus eng verbundenen Klasse II+-Dendritenzellen in der betroffenen nekrotisierenden Dermis unmittelbar neben den infizierten Haarfollikeln und unter der infizierten, degenerierenden Epidermis. Diese Zellen stehen untereinander in Verbindung und bilden anscheinend eine Barrière gegen die Invasion, ein Gorüst für die Immunabwehr und einen Ausgangs punkt für die anschließenden Reparaturvorgänge in der Epidermis. Sie scheinen als Basis eines hochentwickelten lokalen Abwehrsystems der Haut zu fungieren. Resumen Células dendríticas de class II+ se observaron en gran cantidad en la piel de la oveja especialmente en dos localizaciones: a) en la epidermis, en la dermis muy próxima a la epidermis y en anejos cutáneos y b) en las proximidades de los vasos sanguíneos. No parece tratarse de una población homogénea de células puesto que las células de Langerhans, que previamente se habían encontrado en los anejos epidérmicos, se encontraron únicamente en la epidermis utilizando técnicas de detección del acetilcol-inesterasa. Después de la infección con el virus del ectima contagioso ovino se observó una masa de células dendríticas de clase II, dispuestas de forma muy densa, en las proximidades de la dermis necrosada y de los folículos pilosos y de la epidermis infectada. Eatas células interaccionan entre si y parecen formar una barrera contra la invasión, una red inmunitaria de defensa y participar en la reparación de la epidermis; parece ser que esta población de células dendriticas son la base de un sistema de defensa dérmico local altamente integrado.     

Vitamin deficiencies in cattle

Deficiencies of vitamins A, D, K, E and thiamin can cause severe limitations in beef production. In particular, vitamin A and E can be common causes of lost profit, secondary to limitations of reproductive and growth potential. Prolonged dry periods will reduce available A and E in pasture forage, as can ensiling and prolonged storage of harvested feedstuffs. Polioencephalomalacia is a thiamin responsive disorder, associated with high concentrate feeding and lush pastures. Antimetabolites, such as amprolium, will cause thiamine deficiency when fed in excess. Recent information has shown improved performance with supplemental beta carotene and niacin. The positive responses in reproductive performance, noted with cattle fed supplemental beta carotene, was independent of vitamin A. Supplementation of vitamins above National Research Council recommendations can be justified. However, proper evaluation of feed and animal status, and documentation of a response to supplementation is necessary before diagnosing deficiencies of specific nutrients.     

A novel HPLC method for glutathione-insulin transhydrogenase assay using fluorescence labeled insulin

The activity of rat liver glutathione-insulin transhydrogenase (GIT) was measured by HPLC. The degradation of fluorescein isothiocyanate-I (FITC-I)-labeled insulin is separated into several peaks, which are bound different amount of FITC-I. We selected mono-fluorescein-thiocarbamylated insulin to estimate the decrease of insulin content and it became possible to assay GIT activity. This novel method was time-saving and simple, and this system could utilize instead of previous method.     

In situ hybridization analysis of ovarian prostaglandin endoperoxide synthase mRNA throughout the periovulatory period of the ewe.

Cellular alterations in level of expression of mRNA encoding for prostaglandin endoperoxide synthase were quantified within ovarian tissues of sheep obtained before, during and after induction of the preovulatory surge of LH and ovulation with LHRH. This was accomplished by isotopic in situ hybridization using a selective cRNA probe to ovine prostaglandin endoperoxide synthase mRNA. A significant elevation in mRNA was detected within the theca interna of the preovulatory follicle at 8, 16 and 24 hr following administration of LHRH. Very close to the time of ovulation (ie., at 24 hr post-LHRH) a marked rise in mRNA was observed in association with epithelial cells covering the apical surface of the follicle. Ovarian cyclooxygenase metabolites of arachidonic acid produced during the ovulatory process in the ewe originate within the thecal layer and germinal epithelium of the follicle destined to ovulate.