The purpose of the study was to determine whether there were circadian variations in serum osteocalcin in normal horses and to determine whether it was important to regulate the time of blood sampling in clinical investigations. Osteocalcin or bone Gla-protein (BGP), alkaline phosphatase, total calcium, phosphate and total protein were studied over a 24 h period. Blood samples were taken every 60 min from nine adult Standardbred horses. There was a correlation between serum levels of alkaline phosphatase (r = 0.3, p < 0.01), phosphate (r = 0.42, p < 0.01) and serum osteocalcin levels. There was a very marked individual effect on serum levels of osteocalcin and alkaline phosphatase (p < 0.01). This effect was present for phosphate levels but not significant for total calcium. The individual effect was lower and time effect was higher for serum osteocalcin if the subjects were divided into two age groups, one of horses of five years or less (n = 4) and a second group older than five years (n = 5). In both groups a circadian rhythmicity was observed. Serum osteocalcin showed a biphasic pattern. Levels were constant during daytime (light period) and underwent significant variations during the night (dark period), going through a nadir at 2000 h and through a maximum peak at 0500 h. It was concluded that in normal horses the blood osteocalcin level follows a circadian variation. Also daytime (light period) seems to be the more appropriate period for blood sampling.

Intestinal tissues from swine affected withproliferative enteritis were ground, filtered through a 0.65-micrometer pore membrane filter, diluted, and injected into 7-day-old embryonated hens' eggs via the yolk sac. At 2, 4, and 7 days later, yolk sac swab specimens taken from live embryos were cultured for Campylobacter species. Campylobacter hyointestinalis was recovered from eggs injected with tissues of swine with acute hemorrhagic proliferative enteritis at dilutions up to 10-4. Campylobacter mucosalis was recovered from eggs injected with tissues of swine with chronic proliferative enteritis at dilutions up to 10-6. Campylobacter coli was recovered from several specimens without lesions of proliferative enteritis and also from some specimens with lesions of proliferative enteritis. Two previously undescribed hemolytic Campylobacter species designed as hemolytic number 1 and hemolytic number 2 were recovered from normal and experimentally inoculated swine tissues. Few contaminating organisms grow in eggs and these were usually recovered at dilutions of 10-2 or less. Recovery of Campylobacter species by use of these techniques was seldom successful in tissues stored at -70 C for more than 6 months.

We report here genetic recombination between 2USDA-licensed vaccine strains of pseudorabies virus co-inoculated into swine. The vaccine strains, one of which was a conventionally attenuated strain and the other, a genetically engineered deleted strain containing a negative immunologic marker, had complementary genomes. Coinoculation resulted in the creation of novel strains of pseudorabies virus containing negative immunologic markers with restored virulence genes. Plaque-purified recombinant progeny viruses were found in 2 litters of pigs in which both strains were co-inoculated IM, a litter in which both strains were co-inoculated oronasally, and a litter in which the conventionally attenuated strain was inoculated oronasally and the genetically engineered strain was inoculated IM. Recombinant phenotypes and recombinant restriction fragment patterns were observed. The creation, spread, and potential misdiagnosis of these types of recombinant strains could disrupt control and eradication programs that are based on the serologic identification of swine infected with potentially virulent strains of pseudorabies virus.

Sublethal irradiation of BALB/c mice 4 hours prior to inoculation with 5 X 10(4) virulent Brucella abortus, caused significant (P < 0.01) reductions in bacterial numbers in comparison with numbers in unirradiated controls. Numbers of brucellae in the spleen were significantly lower by 5 days after inoculation and decreased thereafter, so that at 2 and 3 weeks after inoculation, there were up to 1,000-fold fewer organisms in the spleen of irradiated mice. The number of brucellae in the spleen increased in irradiated mice thereafter. The course of events in the liver was similar, but developed more slowly, and peak differences in bacterial numbers were about 1 log less. These phenomena were not attributable to differences in implantation of brucellae in the liver or spleen, nor to an abnormal distribution of organisms in other organs of irradiated mice. Irradiation of mice during the plateau phase of infection also resulted in significant (P < 0.05) reductions in bacterial counts in the spleen during the succeeding 4 weeks. Macrophage activation in the spleen, measured by a Listeria monocytogenes-killing assay, was significantly (P < 0.01) increased by irradiation alone at 1 week after inoculation and at that time was significantly (P < 0.01) greater in B abortus-infected, irradiated mice than in B abortus-infected controls. Histologic, cytologic, and immunologic studies revealed that the decrease in numbers of organisms between 1 and 2 weeks after inoculation in irradiated mice occurred at a time when their immune response to B abortus was suppressed and when numbers of neutrophils and monocytes infiltrating the spleen were significantly (P < 0.01) diminished. The increase in numbers of B abortus in organs of irradiated mice that began after the third week coincided with recovery of the immune response and an increase in numbers of neutrophils and monocytes in the infected organs. The course of B abortus infection was not substantially altered during the first 11 days after inoculation in mice infected at the height of a profound monocytopenia and neutropenia induced by azathioprine, a drug that by itself failed to activate macrophages. We hypothesized that, in irradiated mice, a rapid radiation-induced activation of resident macrophages to a brucellacidal state was coupled with an absence of newly formed monocytes in which virulent strains of B abortus could establish persistent infection, and that as susceptible monocytes emerged in mice recovering from the effects of irradiation, chronic infection became established.

The effect of a passive heat and moisture exchanger on tracheal and large airway temperature, as reflected by esophageal temperature at the thoracic inlet, was determined for 12 anesthetized and ventilated tumor-bearing dogs undergoing whole-body hyperthermia at 42 C. Delivered thermal dose to the esophagus and rectum during 120 minutes of whole-body hyperthermia was quantified as the thermal dose summary measure EQ43. The heat and moisture exchanger significantly increased esophageal EQ43 from 7.3 minutes to 12.1 minutes. Esophageal EQ43, however, remained lower than rectal EQ43. Although use of a heat and moisture exchanger improved esophageal temperature during whole-body hyperthermia, presumably through improved airway temperature, additional methods will be necessary to increase esophageal and airway temperature to the target value of 42 C.

In vitro adherence to intestinal epithelial cells by enterotoxigenic Escherichia coli strains bearing K88, K99, F41, or 987P adhesins and of their variants not bearing adhesins (K88-, K99-, or F41-) was investigated in European Large White and Chinese Meishan pigs. Possible relationship between adherence and virulence was also examined. The K88-positive (K88+) strain strongly adhered to intestinal epithelial cells from 26 of 28 Large White pigs. This strain had previously been found to be highly virulent for Large White pigs. The only surviving pig was of nonadherent phenotype, and cells from 4 dehydrated moribund pigs had strong adherence. By contrast, the same K88+ strain found previously to have little pathogenicity for Meishan pigs adhered with variable intensity to cells from 17 of 23 Meishan pigs; correlation was not evident between adherence and virulence. The K99+F41+ strain of porcine origin and the F41+ strain generally adhered strongly to cells from 24 and 23 Meishan pigs, respectively, and to cells from 25 of 26 Large White pigs. Correlation was not found between adherence and virulence for the 2 strains. A K99+F41+ strain of bovine origin adhered to cells from 20 of 22 Meishan and 22 of 23 Large White pigs, and a K99-F41+ variant adhered to cells from 19 of 23 Meishan and 23 of 24 Large White pigs. The adhesin-negative variants never adhered to intestinal epithelial cells. Strain 987 known not to readily produce 987P adhesin after in vitro growth never adhered to cells during the test. Results indicated that K88, K99, and F41 adhesins were responsible for in vitro adherence and, except for the K88+ strain in Large White pigs, adherent phenotype was not a sufficient condition to make a pig susceptible to enterotoxigenic E coli. The contribution of physiologic factors and their genetic origin to the degree of resistance of the individual is not yet completely understood for every enterotoxigenic E coli strain and breed of pig.

Inclusion of lactose in the diets of chickens has been determined to reduce cecal colonization with Salmonella typhimurium. We hypothesized, therefore, that dietary lactose may be a practical means for reducing the prevalence of Salmonella contamination of chicken products. Because some strains of Salmonella are atypical and ferment lactose, we investigated the effects of dietary lactose on cecal colonization with lactose-fermenting S typhimurium. Broiler chicks were inoculated intracloacally with Lac+ S typhimurium selected for resistance to novobiocin and rifampicin. The chicks also were inoculated orally with certain anaerobes that do not effectively inhibit colonization by S typhimurium, but do appear essential for lactose mediated inhibition of cecal colonization. Control chicks were not given dietary lactose, and chicks in the experimental group were fed a diet containing 7% lactose. Enumeration of Lac+ S typhimurium in cecal contents revealed dietary lactose to be effective at controlling this organism. Control was correlated with changes in cecal pH and increases in undissociated volatile fatty acids, especially propionic acid.

From Aug 1985 through July 1986, 720 meat turkey flocks on 160 California premises were monitored and outbreaks of fowl cholera (Pasteurella multocida) were investigated. Data from 43 outbreak (case) flocks were compared with data from 43 nonoutbreak (control) flocks. Outbreak flocks, compared with control flocks, were more likely to be located on premises with higher maximal bird capacity and history of fowl cholera outbreaks. The overall impression was that flocks in larger, newer, more intensively managed premises were at greater risk of fowl cholera outbreaks than were other flocks.

Transcutaneous pulsed-wave Doppler echocardiography was used to obtain velocity signals from the aortic and pulmonary roots of clinically normal adult dogs tranquilized with acepromazine. Doppler-derived variables included peak ejection velocity, ejection time, and velocity-time integral. The cross-sectional areas of the left and right ventricular outflow tracts were estimated from diameters of the respective orifices measured from two-dimensional echocardiographic images. These data were used to calculate stroke volume and cardiac output for each ventricle. Linear, single variable regressions of ejection time, velocity-time integral, and peak velocity with body weight showed no significant correlations. Significant correlations existed between body weight and estimated left and right ventricular stroke volume and cardiac output. A close correspondence existed between pulmonary and aortic determinations of velocity-time integral, stroke volume, and cardiac output. These results provide an initial framework for interpretation of clinical data by veterinary cardiologists.

The effect of pulsed radio frequency therapy (PRFT) was evaluated on seven ponies with no arthritis and in 28 ponies in which arthritis was created using intra-articular amphotericin B to induce synovitis in the right middle carpal joint. The ponies were divided into five treatment and two control groups. Two levels of arthritis were created and two dosage levels of PRFT were evaluated. The effect of PRFT on arthritic and nonarthritic joints was measured by comparing synovial fluid parameters, the degree and duration of lameness, the range of carpal motion, and carpus circumference, for treated and untreated groups. Lesions seen radiographically at gross pathology, and by histopathology were also compared between the treated and control groups. In the ponies with a mild form of induced arthritis, PRFT significantly (p < 0.05) reduced the severity and duration of lameness, swelling of the carpus, and the severity of gross pathological and radiographic changes. In these ponies the synovial acid phosphatase levels were lower, the mucin clot quality was superior, and the synovial protein levels were lower for the ponies receiving PRFT as compared to the arthritic ponies receiving no treatment. A dose response effect was evident. In ponies with a slightly more severe form of arthritis, PRFT was evaluated at one dosage level. The treated ponies were significantly improved over the untreated ponies with respect to carpal range of motion, degree of lameness, carpus swelling, and radiographic lesions. No deleterious effects were noted when normal, PRFT treated, middle carpal joints were compared to contralateral untreated, normal joints. It was concluded that significant beneficial effects resulted when affected ponies were treated with PRFT.