Subepithelial elastic fibers in the bovine gastric mucosa

The arrangement of subepithelial elastic fibers in the bovine gastric mucosa was studied by light and electron microscopy, with special reference to the elastic architecture of the cornified papillae. A common feature of their arrangement was that the fibers, derived from the elastic plexus in the deep layer of the lamina propria, extend perpendicularly toward the epithelium giving off the slender branches that end at the epithelial basement membrane. The connecting branches were observed electron microscopically in the form of oxytalan or slender elaunin fibers. The high frequency of fibers was found in the mucosa of the upper part of the ruminal atrium, the ruminal pillars, the reticular cristae and two kinds of cornified unguiculiform and omasal papillae. Each papilla consisted of the core of three-dimensional elastic network and numerous connecting-twigs arising from the superficial points of the network. The mucosae of the ruminal sacs, the floor of the reticular cells and the abomasum except the pyloric part were relatively poor in elastic fibers. These results suggest that the variation in fiber-arrangement may be relevant to the condition of mechanical stress inflicting on the gastric innersurface.     

Serotypes in Cowdria ruminantium and their relationship with Ehrlichia phagocytophila determined by immunofluorescence

Two tick-borne rickettsial pathogens of ruminants, Cowdria ruminantium (causative agent of heartwater disease) and Ehrlichia phagocytophila (causative agent of tick-borne fever), were successfully cultivated in caprine or ovine neutrophilic granulocytes. Infected cultures were subsequently used as antigens in the indirect fluorescent antibody test. Low-level bilateral serological cross-reactions could be detected between Cowdria and Ehrlichia. In addition, comparison of five Cowdria stocks using immunofluorescence demonstrated the existence of distinct serotypes within the genus of Cowdria. It is concluded that the occurrence of these serotypes will considerably complicate the current serodiagnosis of heartwater.     

Structural and metabolic integrity of sheep external intercostal muscle during extended culture

The objectives of this study were to examine the structural and metabolic integrity of isolated sheep external intercostal muscle bundles following variable lengths of preincubation (0 to 192 h). Samples of intact external intercostal muscle (10 to 15 g), with tendons attached, were prepared from growing wethers and maintained at their resting lengths during preincubation for 0 to 192 h. Protein synthesis (PS), protein degradation (PD), acetate oxidation and ultrastructural integrity of muscle samples were examined at 0 to 192 h, 0 to 96 h, 0 to 48 h and 0 to 96 h following isolation, respectively. Additionally, the effects of variable fetal calf serum (FCS) concentrations (0 to 20%; w/v) on PS and PD and acetate oxidation were examined. Rate of PS increased as preincubation time increased to 192 h; however, most of this increase was due to the proliferation of fibroblasts on the surface of the muscle sample. Addition of cytosine arabinoside to the incubation media prevented the fibroblast-dependent increase in PS; however, it did not entirely prevent the preincubation time-dependent increase in PS. Rate of PD increased greatly upon preincubation. The nitrogen balance of incubated muscles was negative at all times examined. Acetate oxidation was maintained through 12 h of preincubation and thereafter declined. Relatively normal myofibrillar structure was maintained through 48 h of preincubation; however, loss of mitochondrial integrity and dissolution of Z-disks at 48 h and at 96 h of preincubation were evident. Isolated tissues were able to respond to FCS concentration in medium following 48 h of preincubation.     

Encephalitis, proventricular and ventricular myositis, and myenteric ganglioneuritis in an umbrella cockatoo

Myenteric ganglioneuritis and encephalomyelitis were diagnosed in an umbrella cockatoo. The cockatoo exhibited clinical signs that were milder than those associated with this syndrome, such as anorexia, muscle wasting, regurgitation, depression, and changes in fecal consistency. The gross lesions also differed from earlier reports in that only the duodenum and proximal jejunum were grossly dilated. Normally the proventriculus and ventriculus are dilated without visible intestinal changes. The histopathological lesions, however, such as perivascular cuffs in the brain stem and muscular mass of the ventriculus and proventriculus, were similar to earlier reports. A virus was suspected, although transmission and isolation of a virus has not occurred in other reports and was not attempted in this case.     

Subcutaneously implanted tissue chambers — a pharmacokinetic study

The purpose of this study was to characterize the pharmacokinetics of a subcutaneously implanted tissue-chamber model. Thermoplastic tissue chambers were implanted in the paralumbar fossae of six steers. Starting 30 days after implantation, the distribution of intravenously administered antipyrine and phenylbutazone into the tissue chambers was studied. These pharmacokinetic experiments were repeated 10 days later to determine the effect of time after implantation on tissue-chamber distribution. Fifty days after implantation, tissue chambers were drained of transudate, refilled with sterile saline and the rate of influx of endogenous urea, creatinine and albumin was measured. Delayed diffusion of antipyrine and phenylbutazone into tissue chambers was well described using a compartmental model in which tissue-chamber fluid represented the third of three compartments arranged in series. The distribution of antipyrine into tissue chambers was greater than that of phenylbutazone; an observation which is well correlated with the high degree of protein binding of phenylbutazone. There was no effect of time on the penetration of the two agents. Rapid diffusion of urea and creatinine and extremely slow influx of albumin into chambers showed that these chambers formed true interstitial compartments.     

Variations in the concentrations of the immunoglobulins IgG1, IgG2, IgM and IgA in sheep. 2. Changes in the blood of lambs of different breeds and crossbreeds during the course of the rearing period

The sera of 188 lambs from seven breed groups were analyzed for the concentrations of IgG1, IgG2, IgM and IgA by radial immunodiffusion using monospecific antibodies. From each lamb, 14 blood samples were drawn before and 5 samples after weaning. The following results were obtained: 1. Immunoglobulins could not be detected in sera drawn before the first intake of colostrum. 2. In normally suckling lambs, the peak concentrations of maternal immunoglobulins are attained at 0-18 hrs after birth. They can be assessed in a single blood sample drawn between 18 and 24 hrs. 3. The half-life times of maternal immunoglobulin in lamb sera are 11 days for IgG1, 7 days for IgG2, 6 days for IgM and 18 hours for IgA. 4. The absolute peak heights relate to the amounts of colostrum ingested before 12-18 hrs after birth. 5. The decline of maternal immunoglobulins in lamb sera over-laps with the onset of lamb immunoglobulin synthesis. Renewed rises of concentrations are observed for IgG2 after week 2, for IgM after week 3 and for IgG1 after week 7. The concentrations of IgA remain at the low levels characteristic for the serum of grown sheep. 6. The role of immunoglobulin synthesis in suckling lambs is only briefly and to a small extent reduced after weaning.     

The effect of pressure on turkey breast skin

In an attempt to experimentally reproduce focal ulcerative dermatitis (FUD) in turkeys, pressures of 94, 136, and 240 mmHg were applied for 2, 4, or 6 hr daily for 4 consecutive days to unfeathered breast skin of six 9-week-old toms. No gross lesions occurred either immediately after treatment or during a 10-day post-treatment period, and no microscopic changes were present in the skin at the conclusion of the trial. These findings suggest that avian skin is resistant to pressure-induced decubital ulceration and that pressure is unlikely to be either the cause of or a significant contributor to FUD.     

Biomicroscopy of the tear film: the tear film of the pekingese dog

Polarised light biomicroscopy was used to examine the normal pre-corneal tear film in 21 eyes of 12 pekingese dogs. The purpose of the study was to examine the influence of excessive exophthalmos on the pre-corneal tear film in the dog. The majority of the animals were found to have high levels of ocular surface contamination by particulate material and plaques of viscous mucus. Other abnormalities included surface lipid with an abnormal granular (three dogs) or 'curdled' (two dogs) appearance; excessive thinning of the lipid layer of the tear film; and the presence of dark globular structures in two dogs, which were presumed to be abnormal meibomian lipid. Break up of the tear film was observed in one dog. Grossly, a thread of viscous mucus was frequently observed along the margin of the lower eyelid. It is postulated that this thread forms because of the excessively exophthalmic conformation of the breed, which prevents the normal access of effete mucus and entrapped debris to the lower conjunctival fornix. The combination of the above factors in the pekingese is suggested as the mechanism whereby the tear film has a reduced stability, thus enhancing the risk from factors more usually considered to initiate corneal ulceration in the breed. The possible adverse effects of lid splitting for the mass removal of distichiae in exophthalmic dogs is discussed.     

Bacterial culture of blood from critically ill dogs and cats: 100 cases (1985-1987)

Of 100 critically ill dogs and cats, 49 (39 dogs, 10 cats) had bacteremia. Gram-negative bacilli were the most common isolates from the bloodstream of dogs with bacteremia (46%), and gram-positive cocci and anaerobic bacteria were isolated from 36% and 31% of positive cultures, respectively; 15% of positive cultures were polymicrobial. In cats, gram-negative bacilli (especially Salmonella enteritidis) and anaerobic bacteria were the most common isolates, and 30% of positive cultures were polymicrobial. Gram-positive cocci were not isolated from the blood-stream of cats. Odds ratios, adjusted for the combined effects of disease status (severe vs nonsevere), results of bacterial culture of blood result (positive vs negative), and species (dog vs cat) were calculated for mortality in animals in the study. In animals with bacteremia, severe disease increased the risk of death 11.6-fold, compared with the risk in animals with nonsevere disease. Bacteremia increased mortality 10-fold in animals with severe disease, compared with mortality in animals with severe disease without bacteremia. Animals with severe disease and bacteremia were 15.6 times more likely to die than were those with nonsevere disease and negative culture results. In animals with nonsevere disease, culture results (positive vs negative) were not related significantly to mortality. Disease status (severe vs nonsevere) in animals without bacteremia also was not significantly related to mortality. There was no significant difference in overall mortality in dogs, compared with that in cats.(ABSTRACT TRUNCATED AT 250 WORDS)