The developmental pattern of c-fos expression in the rat thalamus following open-field stress stimulation

The thalamic nuclei with their defined set of input-output connections are the primary channel for information flow to the cerebral cortex. Several data suggest that neurons of that area are involved in the response to various aversive stimulations. However the pattern of activation seems to depend on the stress model as well as the stage of maturation. In the present study we would like to check which nuclei of the thalamus show expression of c-fos in the response to the "open field test", and how this response pattern changes during the maturation process. 30 rats of age ranged from P0 to P120 (P-postnatal day) were studied. The experimental group was exposed to the "open field test" for 10 minutes. After perfusion and fixation, brains were cut and stained for c-fos with immunohistochemical method. Our results showed that during development the pattern of c-fos activity in the thalamic nuclei after stress stimulation undergoes significant changes. Distinct c-fos expression was observed in the paraventricular nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus. These findings suggest that these nuclei may play a direct role in the stress reaction involved in the response to the "open field test".     

Risk factors of contamination of pig farms in the Netherlands with pig diseases and agents thereof: a review of the literature

Part of the project 'Clean pigs' an extensive study of literature was made of the risk factors related to the introduction of pathogenic micro-organisms in pigfarms in the Netherlands. On the basis of this study of literature and in close cooperation with the experts of the steering group of the project 'Clean pigs' a number of risk factors relevant for the Dutch pig farming were estimated. The impact of these risk factors on the introduction of the most important pig diseases/-agents in Dutch pig farming was quantified for three different levels of preventive measures. It is shown that many risks can be reduced or even be neglected by the biosecurity measures already applied on pig farms. For most diseases, including list A and B diseases of the OIE list, introduction of new animals is regarded as the main risk factor, but this risk can be reduced in several ways. Besides this, aerogenic transmission and introduction by rodents and pet animals need the most attention. Through specific actions and measures several important risk factors can be diminished or even eliminated.     

Reticular contraction attributes and passage of digesta from the ruminoreticulum in cattle fed roughage diets.

Four nonlactating Holstein dairy cows (BW = 692 +/- 49 kg) were used in a 4 x 4 Latin square design experiment to determine how changes in attributes of reticular contractions were related to changes in passage of digesta from the ruminoreticulum in cattle fed a forage-based diet. Frequencies of reticular contraction during eating, ruminating, and resting phases of the feeding cycle were not affected (P = .09; P = .07; P = .09, respectively) by feeding level. Duration and amplitude of reticular contractions both increased linearly during eating (P = .03; P = .01), ruminating (P = .01; P = .02), and resting (P = .04; P = .02), respectively, as feed intake level increased. After removing the effects of intake, squared partial correlations computed within analyses of covariance indicated that NDF flow was not related to frequency (r2 = .15, P = .20) but was positively correlated with duration (r2 = .76, P = .0001) and amplitude (r2 = .56, P = .003) of contraction, indicating that duration and amplitude of reticular contraction were more associated with duodenal NDF flow than frequency. However, duration of reticular contraction (r2 = .47, P = .014) explained a greater variation in duodenal NDF flow than amplitude (r2 = .011, P = .74). Stepwise multiple regression also indicated that duration of reticular contraction was the attribute most associated (r2 = .76, P = .0001) with duodenal NDF flow. It was concluded that the changes in digesta passage from the ruminoreticulum were associated primarily with changes in the duration of reticular contraction.     

Modulation of function of bovine polymorphonuclear leukocytes and lymphocytes by high temperature in vitro and in vivo.

Function of polymorphonuclear leukocytes (PMNL) and proliferation of lymphocytes after stimulation with mitogens were evaluated in vitro at incubation temperatures of 38.5 and 42 C, and after in vivo heat stress of lactating Holstein cows. Cytochrome-c reduction and random migration of PMNL were reduced when cells were preincubated or incubated at 42 C, but high incubation temperature had little or no effect on phagocytosis and killing of Escherichia coli. Proliferation of lymphocytes was reduced when cells were incubated for 60 hours at 42 C after stimulation with phytohemagglutinin, pokeweed mitogen, or concanavalin A. After stimulation with phytohemagglutinin, lymphocytes were most sensitive to high temperature during the first 24 hours of the 60-hour culture period. High incubation temperature had little effect on viability of cells. In vivo heat stress had no significant effect on responses of PMNL in vitro, but the decrease in proliferation of lymphocytes in vitro at high temperature was less when cells were obtained from heat-stressed cows. Total leukocyte counts in blood and somatic cell counts in milk were higher in heat-stressed cows. Results indicate that: exposure to high temperature in vitro can depress responses of PMNL and lymphocytes; apparent adaptive mechanisms induced by in vivo heat stress provide protection from effects of high temperature seen in vitro; and evidence could not be found to support the hypothesis that reduction in immune function is the basis for increases in the incidence of mastitis during the summer.     

Serum chemistry alterations, including creatine kinase isoenzymes, in furazolidone toxicosis of ducklings: preliminary findings.

Furazolidone induces a cardiotoxicosis when fed in toxic concentrations to newly hatched ducklings. This preliminary experiment was designed to determine if creatine kinase (CK) isoenzymic activities or other serum analytes would be useful as indicators of these cardiac alterations. Sera from 12 ducklings (six fed a control ration and six fed the control ration with 700 mg furazolidone added per kg of feed [700 ppm] for 28 days) were analyzed for CK isoenzymic activities, electrolytes, nitrogenous metabolites, hepatic enzymic activities, bilirubin, and glucose. Statistically significant differences between control and treated groups were detected for creatine kinase MB (CK-MB, cardiac muscle origin) isoenzymic activity and bilirubin, potassium, calcium, and total carbon dioxide concentrations. Differences other than CK-MB isoenzymic activity were generally explained by factors related to the toxicosis or sample handling. These findings suggest that CK-MB isoenzymic activity may be useful to detect and monitor the progress of cardiac injury in furazolidone toxicosis, thereby increasing the usefulness of this model of dilated cardiomyopathy. Our findings, analyzed on the Kodak Ektachem 700 Dry Chemistry Analyzer, are compared with serum chemistry values reported in the literature.     

Technical note: a double L intestinal cannula for cattle

A double L-shaped intestinal cannula was developed in an attempt to overcome problems observed previously with simple T-type cannulas. The cannula was constructed from cyclopolyvinyl chloride water pipe fittings. Construction materials were fairly rigid, but by connecting the split cannula pieces with elastic castration bands the cannula had some flexibility. Placing a short cone over the exposed cannula barrel reduced mechanical damage to the intestine. The double L cannula required a much smaller incision in the intestine during surgical insertion than a T-type cannula; it also simplified replacement. Construction is described; use and performance of the cannula has been satisfactory.     

Diabetes mellitus induced in a dog after administration of corticosteroids and methylprednisolone pulse therapy

An 8-year-old ovariohysterectomized Chow Chow was referred because of dermatologic lesions diagnosed as pemphigus foliaceus. Intolerance to orally administered corticosteroids necessitated the use of methylprednisolone pulse therapy. One week after treatment, diabetes mellitus was diagnosed on the basis of blood and urine test results. For 3 years after treatment, the dog has remained a well-regulated diabetic. Complete remission of pemphigus foliaceus is maintained by alternate-day, orally administered prednisone (0.5 mg/kg of body weight).     

Feedlot performance of Brahman x Angus versus Angus steers during cold weather

Ten Angus and 10 Brahman x Angus F1 steers were used in a 184-d trial to compare feedlot performance during cold weather (-9 to 26 degrees C). Both groups of steers were exposed to the same environment for the same amount of time. All steers were fed for the same number of days regardless of frame score to avoid frame score x environment interactions. Brahman x Angus steers were 30.7 kg heavier (P less than .05) than Angus steers at the start of the trial. Differences in age (Brahman x Angus 40 d younger) for the two breed groups did not affect final live weight or carcass weight. Brahman x Angus steers consumed .2% less feed (P less than .05) as a percentage of BW than Angus steers; however, there was no difference in overall feed efficiency. Angus steers had a higher yield grade, more fat at the 12th rib (P less than .05), and graded 90% Choice; only 10% of the Brahman x Angus were graded Choice. Brahman x Angus steers were taller at the hip (P less than .05) and longer from first rib to aitch bone (P less than .05) and from thoracic vertebrae (T12/T13) to point of hock (P less than .05). Hide thickness determined at the neck, belly, and rump was found to be similar (7.7 mm) between the two groups. Sample hair weight and diameter did not differ between groups. Fiber, fat, protein, and DM digestibility coefficients were similar between groups but Brahman x Angus feces had a higher DM content.(ABSTRACT TRUNCATED AT 250 WORDS)