PubMed Health⌕ Search

Biomedical subjects

J D Huber

Publications and source records attributed to J D Huber.

25 records · Page 2Linked to original sources

Evaluation of a radial immunodiffusion test with polysaccharide B antigen for diagnosis of bovine brucellosis.

A radial immunodiffusion (RID) test employing a polysaccharide antigen (poly B) was compared with tests currently used in the diagnosis of bovine brucellosis. Over 1,000 sera from vaccinated and infected cattle, all of which had been examined bacteriologically, were used to determine the sensitivity and specificity of the RID, card, Rivanol, and complement fixation tests. The RID test identified 90% of the cattle that were shedding Brucella in their milk. Although the complement fixation test was more sensitive, it was less specific than the RID test in cattle vaccinated as adults with Brucella abortus strain 19. A sensitive screening test, such as the card test, in combination with the RID test could be used in diagnostic laboratories, or even in the field, with little additional expense or technical expertise. An additional advantage is that the RID could be applied to sera from adult cattle as early as 2 months after vaccination, when postvaccinal agglutinins and complement-fixing antibodies may still be present. The indirect hemolytic test was used with some of the sera and was found to be a very sensitive test which could be useful in areas of low incidence but would not be practical for large-scale testing in adult-vaccinated herds.

Animals↗

Biotypes of Brucella abortus and their value in epidemiologic studies of infected cattle herds.

Four Texas cattle herds containing cows infected with either Brucella abortus biotype 1, 2, or 4 were studied to determine the probability of transmission of Brucella between adjacent cattle herds, the most probable means by which Brucella was introduced into the herds, and the relative frequency of strain 19 isolation from vaccinated cattle. A total of 1,935 cattle in the four herds were tested for brucellosis; 339 reactors were identified, and isolations of B abortus were made from 143. The biotype of B abortus was used to determine that purchased cattle or reentry of bred heifers into the herds was probably responsible for introducing B abortus and that the biotype was not readily transmitted to adjacent herds. Three (9%) of 32 B abortus isolations from adult-vaccinated cattle were strain 19. The data supported the hypothesis that biotypes can be useful in determining the source of B abortus for cattle and in differentiating field and vaccine strain infections in adult-vaccinated cattle.

Animals↗

The role of NMDA receptors in neonatal cocaine-induced neurotoxicity.

The present study assessed the ability of N-methyl-D-aspartate (NMDA) receptor antagonist, dizocilpine (MK-801), to modulate neonatal cocaine-induced neurobehavioral changes in the rat. Sprague-Dawley rats were randomly assigned on postnatal day 0 (PND 0) to one of four treatment groups. Treatments began on PND 4 and continued until PND 10. Treatments consisted of an oral bolus of either cocaine HCl (40 mg/kg), (+)MK-801 (0.4 mg/kg), (+)MK-801 (0.4 mg/kg) followed 30 min later with cocaine HCl (40 mg/kg) or 0.9% saline. On PND 21, 30, 40 and 60, males and females were examined for stress response using the cold-water swim test. Cocaine-treated male and female rats exhibited significantly diminished tolerance to cold-water stress compared to control and MK-801/cocaine-treated groups. In addition, neonatal exposure to cocaine was associated with increased severity of motor symptoms (tail twitches, wet dog shaking and convulsions) following the administration of NMDA (35 mg/kg). Treatment groups were also tested for pain sensitivity using the tail flick (TF) and hot plate (HP) methods. The results indicated that neonatal cocaine exposure altered pain sensitivity in both tests. NMDA receptor binding studies showed a significant increase in receptor densities in the hippocampus and hypothalamus of the cocaine-treated group compared to control. MK-801 administered to rat pups before cocaine treatment blocked the increase in receptor density. The results indicated that neonatal cocaine exposure was associated with altered responses to NMDA, stress tolerance and pain sensitivity. Moreover, the pretreatment with NMDA receptor antagonist, MK-801, abolished or attenuated these cocaine-induced neurobehavioral changes.

Adrenocorticotropic Hormone↗