Effects of dopamine administration on cecal mechanical activity and cecal blood flow in conscious healthy horses

Lateral cecal arterial blood flow, carotid arterial pressure, heart rate, and mechanical activity of the circular and longitudinal muscle layers of the cecal body were measured in 7 conscious healthy horses during IV infusion of physiologic saline solution for 60 minutes (control), during a 60-minute IV infusion of dopamine (at dosages of 1, 2.5, and 5 micrograms/kg/min), and for 60 minutes after IV infusion of dopamine. The mean values for lateral cecal arterial blood flow during IV infusion of dopamine at a dosage of either 1 or 2.5 micrograms/kg/min were not significantly different from the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. The mean values for lateral cecal arterial blood flow, however, were significantly greater during IV infusion of dopamine at a dosage of 5 micrograms/kg/min than the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. Intravenous infusion of dopamine at 1 and 2.5 micrograms/kg/min did not significantly change the mean values for carotid arterial pressure. In contrast, the mean values for carotid arterial pressure were significantly less during IV infusion of dopamine at dosages of 2.5 and 5 micrograms/kg/min than during infusion of saline solution. The mean values for heart rate were not significantly altered by infusion of dopamine at a dosage of either 1 or 2.5 micrograms/kg/min, but infusion of dopamine at a dosage of 5 micrograms/kg/min significantly increased heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oral fowlpox vaccination in chickens.

Chickens were given various fowlpox vaccines on food pellets--a commercial vaccine (strain M), and the same strain after a single passage on chorio-allantoic membrane or in chicken embryo fibroblasts. All three oral vaccines induced antibodies at levels similar to those induced by commercial strain M administered to the wingweb. The oral vaccine derived from chorio-allantoic membrane gave protection similar to that obtained with vaccine administered by the wingweb, but this required a thousandfold more virus.     

Additive and synergistic pharmacologic inhibition of equine fibrinoligase (factor XIIIa*-like) biochemical activity.

A selected group of pharmaceutical compounds were evaluated for the ability to inhibit the biochemical activity of fibrinoligase (coagulation factor XIIIa*) in pooled equine plasma. Criteria for the pharmaceuticals selected were based on the mechanism of the transglutamination biochemical reaction mediated by coagulation factor XIIa*. These criteria were complemented by recognition of the molecular configuration and chemical composition of amino acid residue side chains involved in the process of covalent fibrin monomer polymerization (cross-linking, transglutamination) mediated by this enzyme. Each pharmaceutical was evaluated individually and in combination with other potential coagulation factor XIIIa* inhibitors in an effort to detect additive and synergistic phenomenon. In this context, pharmaceuticals with a carbonylamide (eg, cefuroxime, Girard's reagent-P, prolinamide) were applied in concert with compounds with a terminal amine (eg, D-arginine, L-lysine) functional group. In concept, this method theoretically served to competitively simulate glutamine and lysine amino acid residues within strands of fibrin monomer substrate involved in phase I (carbonylamide) and phase II (terminal amine) of the transglutamination reaction (covalent fibrin monomer cross-linking). Halogen-dinitro and ethylene compounds were also evaluated because of their reported ability to inactivate enzyme systems dependent on an intact sulfhydryl group located at their biochemically active site (eg, cystine amino acid residue). This group of pharmaceutical compounds failed to inhibit the biochemical activity mediated by coagulation factor XIIIa* in equine plasma.     

Season and location effects on serum and liver mineral concentrations of Senepol cattle on St Croix,virgin islands

Summary Serum and liver concentrations of selected macro-and trace minerals were determined in Senepol cattle at 8 sites (4 each in a high and low rainfall region) during the dry and wet season on St Croix. At each site an average of 15 mature, lactating cows, grazing native grass/legume pastures without supplementation were blood sampled each season. Liver samples were collected (n=51) at slaughter from mature animals originating from the same sites. A preliminary analysis indicated no differences in serum mineral concentrations between mature lactating cows and growing heifers. There were differences between sites for serum magnesium (Mg) (P<0·001), copper (Cu) (P<0·05) selenium (Se) (P<0·001) and zinc (Zn) (P<0·01) in the dry season, and for Cu (P<0·01), iron (Fe) (P<0·001) and Zn (P<0·01) in the wet season. Higher (P<0·001) serum concentrations of Mg, Cu, Fe and Zn were observed in the dry season, while Se was higher (P<0·001) in the wet season. Liver concentrations of Cu and Fe were lower (P<0·01) and liver molybdenum (Mo) (P<0·001) and Se (P<0·05) higher during the dry season. The seasonal differences in serum Cu, Se and Zn concentrations have not been observed in other studies in the Central American region. More than 50% of serum samples were deficient in phosphorus (P) regardless of season, and in Cu and Zn during the wet season. Mineral supplementation should be considered.

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Resumen Se determinó la concentración de minerales (macro y trazas) seleccionados, en ganado Senepol en ocho sitios: cuatro de ellos en una región de alta precipitación y los otros cuatro en regiones de baja precipitación pluvial, durante la estación seca y lluviosa en la isla de Sta Cruz. En cada sitio, un promedio de 15 vacas lactantes, pastoreando pasto nativo y pasturas con leguminosas sin suplementación, se sangraron en cada estación. Se colectó tejido hepático (n=51) en el matadero local, de animales maduros provenientes de los sitios estudiados. Un análisis preliminar, no indicó diferencias en concentraciones séricas de minerales entre animales maduros lactandos y novillas en crecimiento. Hubo diferencias en cuanto a localización respecto al magnesio sérico (Mg) (P<0·001), cobre (Cu) (P<0·05) selenio (Se) (P<0·001) y zinc (Zn) (P<0·01) en la estación seca y para Cu (P<0·01), hierro (Fe) (P<0·001) y Zn (P<0·01) en la estación lluviosa. Se observaron concentracionas séricas màs altas (P<0·001) de Mg, Cu, Fe y Zn en la estación seca, mientras que el Se fue más alto (P<0·001) en la estación lluviosa. Las concentraciones hepáticas de Cu y Fe fueron bajas (P<0·01) y las de molibdeno hepático (Mo) (P<0·001) y Se (P<0·05), fueron altas durante la estación seca. Las diferencias estacionales en concentraciones de Cu, Se, y Zn sérico, no habian sido observadas en otros estudios en la región centroamericana. Mas de 50 por ciento de las muestras de suero fueron deficientes en fósforo (P) sin tener en cuenta la estación y en Cu y Zn durante la estación lluviosa. Se sugiere la necesidas de suplementación mineral.

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Résumé Les auteurs ont déterminé les concentrations sériques et hépatiques d'un certain nombre d'oligo éléments et de sels minéraux sur des bovins Senepol éléves sur 8 sites (quatre pour chaque région à forte et faible pluviométrie) pendant la saison humide et la saison sèche sur l'lle Sainte Croix. Sur chaque site, des prélèvements de sang ont été effectués pendant chaque saison sur la base d'une moyenne de 15 vaches adultes en lactation, paturant sur des parcours naturels de graminées/légumineuses, sans complémentation. Les prélèvements de foie (n=51) ont été collectés à l'abattoir sur des animaux adultes originaires de ces mêmes endroits. Une analyse préliminaire n'a indiqué aucune différence dans les concentrations minérales du sérum entre les vaches adultes en lactation et les génisses en cours de croissance. Il y avait des différences entre les sites pour le magnésium sérique (Mg) (P<0,001), le cuivre (Cu) (P<0,05), le sélénium (Se) (P<0,001) et le zinc (Zn) (P<0,01) en saison sèche et pour le cuivre (Cu) (P<0,01), le fer (Fe) (P<0,001) et le zinc (Zn) (P<0,01) en saison humide. En saison sèche, des concentrations plus élevées (P<0,001) on été observées pour Mg, Cu, Fe et Zn alors que le sélénium (Se) était plus abondant en saison humide. Les concentrations hépatiques en Cu et Fe étaient plus basses (P<0,01) mais celles en Molybdène (Mo) (P<0,001) et en sélénium (P<0,05) plus élevées au cours de la saison sèche. Les différences saisonnières entre les concentrations sériques de Cu, Se et Zn n'ont pas été observées en Amérique centrale par d'autres auteurs. Plus de 50 p. 100 des échantillons de sérum étaient carencés en phosphore (P) quelle que soit la saison, et en Cu et Zn pendant la saison humide. Il conviendrait de prendre en considération la complémentation minérale.

     

The effect of fatty acids in the feed on xanthine dehydrogenase activity in the Japanese quail]

The aim of the present study is to determine the effect of different fatty acids on the amino acid catabolism judged on the level of xanthine dehydrogenase (XDH). The model system of protein depletion with subsequent repletion was used in the trial consisted of Japanese quails 71 days old. In the period of protein repletion, the fatty acid (stearic, palmitic, oleic, linolenic, linoleic and lauric, respectively) was used instead of common fatty compound in the diet. Specific activities of XDH in liver, kidneys and pancreas of quails were tested dynamically from the first to the eighth day of feeding. It was demonstrated that neither lauric, palmitic nor oleic acid, respectively, had an effect on the development of the specific activity of XDH (Fig. 3). Stearic acid as a sole fatty compound in the diet however evoked reactibility of XDH in liver or in pancreas in different way as in kidneys (Fig. 4). The dynamics of the XDH development in kidneys was practically identical than that in the control. However, XDH in liver and pancreas raised statistically already from the first day of feeding. The effects of linoleic and linolenic acids on the development of specific activity of XDH were organ selective, too (Fig. 5). XDH in kidneys was shown in the same manner as in the control group. In liver and pancreas, however, the specific activity of XDH was diminished markedly just from the first day of feeding.     

Analytical methods for mycotoxins

Biological, physico-chemical and immunochemical methods are available today for solving the multiple problems which turn up in the course of mycotoxin diagnosis and mycotoxin research. In this review, selected analysis techniques are presented and their limits and possibilities are discussed. The biological methods (chicken-embryo-test, skin irritation test, cell cultures) indicate only toxicities, mostly without further specification for mycotoxins. In contrast, modern physico-chemical analysis (DC, HPLC, CLC, MS) allows the detection of defined mycotoxins in the picogram range; these methods should be employed or official and judicial purposes. The recently developed immunochemical methods (RIA, EIA) are characterized by a simple sample preparation, a short test duration and a high sensitivity; they could be used as a screening method in the course of mycotoxicological control of food and feed.     

Serological survey of the incidence of Hypoderma bovis in cattle in 1988

Sera from 74,502 cattle from 3087 farms in England and Wales were tested for the presence of antibodies against Hypoderma bovis in the spring of 1988. Twenty-nine positive sera were identified on 18 premises and these animals were treated; an examination of 6030 sera taken from 108 neighbouring herds identified another 17 seropositive animals on 10 farms in Devon, Cornwall, Lancashire, Shropshire and Powys, indicating that these counties still harbour populations of warble fly.     

Prevalence of Toxoplasma gondii infection in raccoons.

Serum samples from 427 raccoons (93 from Pennsylvania, 45 from New Jersey, 72 from South Carolina, 68 from Virginia, 30 from Iowa, and 119 from Ohio) were evaluated for Toxoplasma gondii antibodies in dilutions of 1:25, 1:50, and 1:500. The distribution of T gondii antibody titers was less than 1:25 for 212 raccoons (49.6%), 1:25 for 34 raccoons (7.9%), 1:50 for 117 raccoons (27.4%), and greater than or equal to 1:500 for 64 raccoons (14.9%). Tissue cysts were seen in the liver, and tachyzoites were in the brain of a raccoon with abnormal neurologic signs and concurrent infection with canine distemper virus. Organisms in the liver were stained with anti-T gondii serum, and the raccoon had a T gondii titer of 1:160 in the agglutination test.     

Theileria parva: the immune status of calves born of dams immunised against East Coast fever

Eight Friesian cross cows three months pregnant to a single Friesian bull were immunised against East Coast fever by infection with Theileria parva (Muguga) sporozoite stabilate and treatment with pyrrolidino-methyl tetracycline. They were challenged with the homologous stock four times before calving and a fifth time after calving, and resisted all five challenges which killed all of the five groups of five susceptible controls. Calves born to these hyperimmunised dams were fully susceptible on challenge with the same stabilate, as were susceptible cows from the same farm and their calves. In both instances the calves died three to seven days earlier than the cows which were approximately 10 times heavier. These results show that one- to two-month-old taurine calves from artificially immunised dams are not protected from experimental T parva sporozoite challenge and that there is no inherent calfhood resistance to East Coast fever.