Evaluation of cortical bone damage and axial holding power of nonthreaded and enhanced threaded pins placed with and without drilling of a pilot hole in femurs from canine cadavers.

Objective: To evaluate the in vitro axial extraction forces necessary to remove pins and to evaluate mechanical trauma resulting from pin insertion, using various types of pins and insertion techniques.

Design: Prospective, controlled study.

Subjects: Femurs of cadavers of dogs.

Equine glucose-6-phosphate dehydrogenase deficiency.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a well-characterized X-linked inherited disorder in humans but has not been reported in horses. We describe a persistent hemolytic anemia and hyperbilirubinemia due to a severe G6PD deficiency in an American Saddlebred colt. Other abnormalities in the colt's erythrocytes as compared with those of healthy horses (n = 22-35) included increased activities of hexokinase and pyruvate kinase, decreased concentrations of reduced glutathione and reduced nicotinamide adenine dinucleotide phosphate (NADP), and increased concentration of oxidized NADP.

Pathogenicity of a bovine attaching effacing Escherichia coli isolate lacking Shiga-like toxins.

Escherichia coli isolate 7996-90, obtained from a calf with diarrhea, had negative results of tests for K-88, K-99, 987P, F41, CS31A, F1845, F165 or E. coli adherence factor adhesins and had negative results of tests for the toxins heat-labile, heat-stable A, heat-stable B, Shiga-like toxin (SLT)-I or SLT-II. Strain 7996-90 had localized adherence to HEp-2 cells, caused actin rearrangement in host cells to which it adhered, hybridized with the eaeA probe, and produced the 94-kd outer membrane protein associated with attaching effacing lesions.

In vitro model of adhesion and invasion by Bacillus piliformis.

An in vitro model of Bacillus piliformis infection was developed to investigate the mechanisms of adhesion and internalization of this obligate intracellular bacterium. Adhesion and internalization events were examined by electron microscopic evaluation of infected Caco-2 cell monolayers. A few bacteria were identified in apical surface invaginations and in vacuoles subjacent to the apical surface, whereas the majority of bacteria were observed free within the cytoplasm, suggesting that B.

Identification of common surface antigens among Babesia bigemina isolates by using monoclonal antibodies.

A group of monoclonal antibodies (MAb) was used to immunochemically characterize Babesia bigemina surface components. Two surface reactive MAb by an IFAT test were subsequently shown to bind to epitopes on the external surface of the parasite plasma membrane as evidenced by immunoelectron microscopy. Parasite components with relative sizes of 68, 62, 60, 58, 56, 54, 51, 49, 48, 47, 43, 36 kDa were identified with the group of MAb in at least 6 geographically different B.

Purification of the erythrocytic stages of Babesia bigemina from cultures.

Exposure of erythrocytes infected with Babesia bigemina to glycerol-enhanced osmotic shock yielded preparations containing infected erythrocyte ghosts, free parasites, and some intact erythrocytes. The released parasites were purified and concentrated by centrifugation in Percoll gradient. Recovered free parasites were shown by the fluorescein acetate technique to be metabolically active, but their infectivity in vitro was low.

Naturally acquired enteric adenovirus infection in Syrian hamsters (Mesocricetus auratus).

Intranuclear inclusions indicative of adenovirus infection were detected microscopically in formalin-fixed intestinal tissues from preweanling Syrian hamsters. The amphophilic intranuclear inclusion bodies were observed in ileal enterocytes from 16-to 24-day-old hamsters. Electron microscopy revealed large numbers of 72 +/- 3-nm viral particles typical of adenoviridae in enterocytic nuclei.

Isolation of a Campylobacter-like organism from healthy Syrian hamsters (Mesocricetus auratus).

A Campylobacter-like organism was isolated from the ilea of normal hamsters. The organism was isolated from an ileal homogenate which was passed through a filter (0.65-micron pore size) and cultured on blood-agar plates in a microaerophilic atmosphere at 37 degrees C.

Intestinal capillary filtration in acute and chronic portal hypertension.

The impact of acute and chronic portal hypertension on the dynamics of intestinal microvascular fluid exchange was examined in anesthetized, fasted, sham-operated control rats with normal portal pressures (CON), during acute elevations in portal pressure (APH) in control rats, and in rats in which chronic portal hypertension (CPH) was produced by calibrated stenosis of the portal vein 10 days prior to the experiments. Although intestinal blood flow and vascular resistance were not altered by APH in control rats, CPH was associated with an increased intestinal blood flow and reduced intestinal vascular resistance when compared with CON and APH. Intestinal capillary pressure and lymph flow were elevated in APH and CPH relative to control values.

The pathology of experimental cytauxzoonosis.

Clinical, gross post mortem, histological and electron-microscopical data were collected from cats serially killed following experimental infection with Cytauxzoon felis. The agent was originally isolated from domestic cats with naturally occurring fatal cytauxzoonosis. Morphologically, the blood phase of feline Cytauxzoon appeared similar or identical to that described for cases of cytauxzoonosis in African ruminants and closely resembled also the blood phases of Theileria spp.

Composition and properties of very low density lipoproteins secreted by the perfused rat liver and subfractionated by affinity chromatography.

Very low density lipoproteins (VLDL) were isolated from the perfusate of rat livers infused with a complex of oleic acid bound to bovine serum albumin. Very low density lipoprotein (VLDL) secretion, bile flow, histopathology, and transmission electron microscopy indicated that secretory functions but not morphologic integrity of the livers were maintained during the procedure. Plasma VLDL and liver perfusate VLDL did not have similar size distribution.

Ultrastructural study of the equine cecum during onset of laminitis.

The morphologic and pathologic changes which occurred within the cecal mucosa of 4 horses during the onset of laminitis were determined from cecal biopsy materials obtained via a cecal fistula; the laminitis was induced with carbohydrate overload. The cecal epithelial mucosa specimens were obtained at 0 (base line), 24, 32, 48, and 72 hours after horses were given carbohydrate overload, and these were fixed and subsequently photographed. Changes in the cecal epithelium were examined by transmission electron and scanning electron microscopies.

Scanning electron microscopy of bovine corneas irradiated with sun lamps and challenge exposed with Moraxella bovis.

Effects of UV radiation and irradiation followed by challenge exposure with Moraxella bovis on the corneal epithelium were studied in 6 calves by scanning electron microscopy. After UV irradiation, the number of dark cells comprising the surface epithelium increased. Many epithelial cells were in various states of degeneration and were characterized initially by large round nuclei, whereas sloughing and peeling were characteristic of the last degenerative stage.

Effect of intrauterine infusion of Escherichia coli endotoxin in postpartum pony mares.

Fifteen pony mares were assigned to 1 of 3 treatment groups after foaling: Group 1, 35 ml of sterile saline solution was infused into the uterine lumen within 24 hours after parturition (6 mares); group 2, 300 mg of Escherichia coli endotoxin was infused into the uterine lumen within 24 hours after parturition (6 mares); and group 3, 300 mg of E coli endotoxin was infused into the uterine lumen between 72 and 96 hours after parturition (3 mares). Rectal temperatures were taken at -1, -0.5, 0, 0.

Measurement of phagocytosis using fluorescent latex beads.

Fluorescent monodisperse latex beads and a computer-centered spectrofluorimeter were used to devise a sensitive new assay for phagocytosis. LM fibroblasts, a transformed cell line with a high endocytic rate, were exposed to fluoresbrite beads and the following parameters were investigated: incubation time, incubation temperature and bead/cell ratio. The bead uptake was linear for 60 min over a wide range of bead/cell ratios up to 130 beads/cell.

Parvovirus-like enteropathy in Missouri turkeys.

A viral enteric disease of young turkeys characterized by stunting of affected birds, diarrhea, and increased mortality is described. Eosinophilic intranuclear inclusion bodies were found in the absorptive epithelial cells of the ileum. Electron microscopy of formalin-fixed tissue revealed that the intestinal inclusions contained numerous loosely packed 15-to 20-nm hexagonal particles.

LM fibroblast plasma membrane subfractionation by affinity chromatography on con A-sepharose.

Affinity chromatography was used to determine the heterogeneity and orientation of plasma membrane vesicles isolated from LM fibroblasts subjected to Dounce homogenization. Two plasma membrane subfractions were obtained by Con A-Sepharose affinity chromatography of LM fibroblast plasma membranes prepared by Dounce homogenization. The desmosterol-phospholipid molar ratio, the phospholipid composition, and the phospholipid fatty acid composition were almost identical between the two fractions.

Atherosclerosis in rabbits fed a low cholesterol diet for five years.

Rabbits were fed a low cholesterol atherogenic diet for up to 5 years. Arterial lesions during the first 12 months consisted of smooth muscle cell and lipid accumulation in the intima, with smaller amounts of elastin and collagen. By 24 months, considerable degeneration and necrosis of smooth muscle foam cells had occurred, lipid had decreased in relative proportion, and collagen was predominant.

Characterization of the inclusion limiting membrane of anaplasma marginale by immunoferritin labeling.

Purified anti-erythrocytic membrane antibody (PAMA) was prepared from rabbit anti-bovine erythrocyte serum by an adsorption and elution technique, utilizing bovine erythrocytes. Lysed and washed anaplasma-infected erythrocytes were incubated with PAMA or control reagents. Specimens were then subjected to immunoferritin labeling with ferritin antiglobulin conjugate.

Transmissible gastroenteritis in neonatal dogs: experimental intestinal infection with transmissible gastroenteritis virus.

Fourteen neonatal dogs (4 through 11 days of age) were exposed orally to the Purdue strain of transmissible gastroenteritis (TGE) virus, and six dogs of similar age were noninoculated controls. Clinical signs of enteric disease did not develop. Both exposed and control dogs had normal fecal passages and appetite throughout the experiment.

Use of a tissue sectioner to expose internal structures of biological samples for scanning electron microscopy.

A procedure yielding sections of unembedded biological samples for observation by scanning electron microscopy is described. Sections of samples, fixed and hardened in OsO4, were obtained in quantity with a tissue sectioner. Subsequent treatments to osmium-coat cut surfaces were employed prior to critical point drying.

Electron microscopy of vesicular-arbuscular mycorrhizae of yellow poplar. IV. Host-endophyte interactions during arbuscular deterioration 1,2.

Scanning electron stereoscopy and transmission electron microscopy were used to correlate morphological alterations and cytological phenomena associated with deterioration of arbuscules in yellow poplar mycorrhizae. Arbuscular degradation was initiated at the tips of the finest branches and progressed basipetally. Cytoplasm in arbuscular hyphae progressively deteriorated and was followed by collapse of the fungal walls.