Effects of alkaline hydrogen peroxide treatment of cotton and wheat straw on cellulose crystallinity and on composition and site and extent of disappearance of wheat straw cell wall phenolics and monosaccharides by sheep

Effects of alkaline hydrogen peroxide (AHP) treatment on cellulose crystallinity and cell wall phenolic monomer and monosaccharide composition were measured using cotton and wheat straw (WS). Two WS treatments were used in this study, Type I WS, for which pH is not regulated during AHP treatment, and Type II WS, for which pH is regulated at 11.5 +/- .2 during AHP treatment. Wheat straw had a lower degree of cellulose crystallinity than cotton, but no differences occurred between treated and untreated substrates. Alkali-labile and nitrobenzene-extractable phenolic monomer concentrations were generally lower for Type I and Type II WS compared with untreated WS. Concentrations of glucose were higher and xylose and arabinose lower in Types I and II WS than in untreated WS. Disappearance of alkali-labile phenolic monomers and cell wall monosaccharides by wethers fed diets containing Type I (Exp. 1) or Type II (Exp. 2) AHP-treated WS were determined. Apparent digestibility of glucose and xylose before the duodenum, and of glucose, xylose and arabinose in the total tract, was greatest (P less than .05) when sheep were fed AHP-treated WS diets in both experiments. In Exp. 2, disappearance of alkali-labile phenolic monomers was greatest (P less than .05) before the duodenum and in the total tract when sheep were fed AHP-treated WS diets. Treatment of WS with AHP modified cell wall composition and increased cell wall monosaccharide digestion by sheep.     

Electromyographic evaluation of horses with laryngeal hemiplegia

Thirty-eight horses suspected of having laryngeal hemiplegia had electromyograms (EMGs) performed on the dorsal cricoarytenoid muscle (DCAM). Electromyographic abnormalities consisted of fibrillation potentials, positive sharp waves, bizarre high frequency discharges, and reduced insertional activity. Normal motor activity consisted of motor unit activity during inspiration, or less frequently motor unit activity during inspiration with subsequent tonic motor activity. In affected muscles, motor unit activity was often absent but when present there was activity consisting of motor units which did not correspond to a particular phase of respiration or it was consistent with normal motor unit activity.     

Chlamydia immunoreactivity in birds with psittacosis: localization of chlamydiae by the peroxidase-antiperoxidase method

Diagnosis of psittacosis (infection with Chlamydia psittaci) has traditionally been dependent upon culture or demonstration of chlamydiae in tissues by cytochemical stains such as the Gimenez or Macchiavello's stain. In this study, a peroxidase-antiperoxidase (PAP) technique that employs a commercially available monoclonal antibody directed against Chlamydia is used to demonstrate chlamydiae in the necropsy tissues of nine birds. Chlamydiae were identified in air sacs (83%), liver (78%), spleen (78%), small intestines (67%), large intestines (44%), and kidneys (33%). Usually chlamydiae were associated with microscopic lesions, but in 75% of large intestines examined, organisms were identified within the lumen of histologically normal intestine. PAP studies revealed numerous chlamydiae that were inapparent in hematoxylin-and-eosin-stained sections. These results demonstrate the utility and sensitivity of the PAP method in the identification of chlamydiae in microscopic sections.     

Changes in leukocyte populations in pulmonary lavage fluids of calves after inhalation of Pasteurella haemolytica

The distribution of leukocytes in bovine bronchoalveolar lavage fluids was determined in 15 calves at various times after aerosol exposure to Pasteurella haemolytica. For comparison, 10 calves were exposed to aerosols of phosphate-buffered saline solution; 15 calves, to Staphylococcus epidermidis; and 10 calves, to Salmonella typhimurium endotoxin. At 10 minutes after inhalation exposure for each group, the predominant cell type was the macrophage. Macrophages remained the predominant cell type throughout each lavage interval for calves exposed to phosphate-buffered saline solution and Staph epidermidis. For calves exposed to P haemolytica, there was a decrease in the percentage of macrophages detectable by 30 minutes after exposure, with a corresponding increase in the percentage of neutrophils. Sixty minutes after the inhalation exposure to P haemolytica, the percentages of macrophages and neutrophils in the lavage fluid were equal. By 240 minutes after exposure to P haemolytica, greater than 90% of the cells in the lavage fluids was neutrophils. The increase in the percentage of neutrophils in lavage fluids from calves exposed to S typhimurium endotoxin was similar to that seen for the calves exposed to P haemolytica.     

Productivity of different cow genotypes: culling rates and early calf performance

Records of Jersey-sired (Jx), Santa Gertrudis-sired (Sx), Charolais-sired (Cx) and straightbred Hereford (H) cows were examined to determine culling rates, birth dates, weaning weights and average daily gains of their first, second and third calves. Culling categories were defined on the basis of number of calves weaned before removal from the herd. Calf performance data were analyzed by cow breed group and cow culling category. A second-degree polynomial model fit the data of all breeds, and accounted for a greater proportion of variation in percentage culled than did the linear model (P less than .05). Total percentage culled through the study were 71, 67, 54 and 53 for the H, Sx, Cx and Jx cows, respectively. Culling rates in the H and Sx cows tended to be higher at earlier ages than in the Cx and Jx cows. Cow-culling category was a significant source of variation only on birth date of first calves. Cows culled after one calf had calves that were born later than cows in the other two categories (P less than .05). Birth date, weaning weight and average daily gain of first calves varied with cow breed in that Jx cows had calves that were born earlier, gained faster and weaned heavier than first calves from the other breed groups (P less than .05). First calves from Sx and Cx cows gained faster (P less than .05) than calves from H cows.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrastructural and clinicopathological studies on the toxicity of cationic acrylamide-based flocculant to rainbow trout

Rainbow trout (Salmo gairdneri) of two age groups were exposed to a cationic acrylamide-based flocculant at various concentrations in static bioassay chambers. At lethal concentrations the flocculant produced severe gill alterations in all fish. The principal alterations were necrosis and separation of the respiratory epithelial cells covering secondary lamellae. Many necrotic chloride cells were also seen, their apical plasma membrane was destroyed, and mitochondria were swollen with separated cristae. An influx of a large amount of fluid into the interstitial spaces caused partial or complete separation of subepithelial spaces from the covering epithelial cells and basement membranes of underlying blood vessels. Clinicopathological alterations included marked decreases in blood pH, partial pressure of oxygen, bicarbonate and plasma sodium, and chloride concentrations. Hematocrit, total protein, and blood glucose were increased. Fish exposed to sublethal concentrations had gill alterations characterized by hypercellularity and thickening of the secondary lamellae. These were due to undifferentiated cell proliferation and macrophage and lymphocyte infiltration between the covering epithelial cells and the underlying blood vessels. Macrophages and undifferentiated cells had large phagolysosomes containing cytoplasmic organelles, an indication of cell injury and increased turnover.     

Open drainage, intra-articular and systemic antibiotics in the treatment of septic arthritis/tenosynovitis in horses.

Open drainage was used to treat 26 horses with persistent or severe septic arthritis/tenosynovitis. Infected synovial structures were drained through a small (3 cm) arthrotomy incision that was left open and protected by a sterile bandage. Joint lavage was performed in all 26 horses. In addition to systemic antibiotics, 23 of these horses were also treated with intra-articular antibiotics; amikacin (17 horses), gentamycin (2 horses), cefazolin (2 horses), and 2 horses were injected at different times with gentamycin and amikacin. The infection was eliminated from the involved synovial structures in 25 of 26 horses; 24 survived and were released from the hospital. The arthrotomy incisions healed by granulation in 16 horses; in 9 horses the arthrotomy incision was sutured closed once the infection was eliminated. Seventeen horses returned to soundness and resumed athletic function. Open drainage was an effective method of achieving chronic drainage from a joint or tendon sheath. It is indicated in horses that have established intra-synovial infections or in horses that do not respond to joint lavage through needles.     

Diagnosis of chlamydial infection in pet birds: comparison of cloacal-swab culture and peroxidase-antiperoxidase methods

Cloacal swabs were examined using a peroxidase-antiperoxidase (PAP) method that employs a monoclonal antibody to chlamydiae. The specificity and sensitivity of cloacal-swab PAP examination and the prevalence of chlamydiosis were calculated using both culture and tissue PAP evaluation as standards. The prevalence of chlamydial infections was 9.3% as determined by culture and 46.3% as judged by tissue PAP evaluation. Cloacal-swab PAP examination yielded a sensitivity of 71.4% and specificity of 85.5% when compared with culture results and a sensitivity of 81% and specificity of 85.7% compared with tissue PAP results. Culture had a sensitivity of 47.4% and specificity of 100% compared with tissue PAP results. Similarly, the efficiency of cloacal-swab PAP test was about 84% compared with culture results and tissue PAP. The efficiency of culture compared with tissue PAP was 73.1%.     

Antimicrobial susceptibility of bacterial isolates from 233 horses with musculoskeletal infection during 1979-1989.

Bacterial culture and susceptibility results were analysed from 233 horses with septic arthritis/tenosynovitis or osteomyelitis that developed after fracture repair. Antibiotics were deemed highly effective, effective or ineffective if > or = 85%, 70-84.9% or < 70% of the isolates were susceptible respectively. In total, 424 bacterial types were isolated; 386 were aerobic or facultative and 38 were anaerobic. Enterobacteriaceae (28.8%) were the most common bacterial group isolated, followed by non-beta-haemolytic streptococci (13.0%), coagulase-positive staphylococci (11.8%), beta-haemolytic streptococci (9.4%), and coagulase-negative staphylococci (7.3%). The remainder of the organisms were other Gram-negative (15.8%), other Gram-positive (2.3%) and miscellaneous (2.6%) bacteria. Penicillin and ampicillin were highly effective against beta-haemolytic streptococci, but were ineffective against other bacteria. Ampicillin was no more effective than penicillin against most bacteria. Amikacin was the most effective antibiotic against the wide range of bacteria isolated in this study. Amikacin was highly effective against coagulase-positive staphylococci, Enterobacteriaceae and Pseudomonas and was effective against coagulase-negative staphylococci and Actinobacillus. Gentamycin was not highly effective against any bacterial group; but was effective against coagulase-positive and negative staphylococci, Pseudomonas, Salmonella and Actinobacillus. Kanamycin was ineffective against all bacteria with the exception of Actinobacillus. Cephalothin was highly effective against beta-haemolytic streptococci, coagulase-positive staphylococci and Actinobacillus and was effective against coagulase-negative staphylococci.(ABSTRACT TRUNCATED AT 250 WORDS)     

Contrast-enhanced computed tomography and myelography in six horses with cervical stenotic myelopathy.

The cervical spines of 6 horses with cervical stenotic myelopathy (CSM) were examined using myelography and contrast-enhanced computed tomography (CECT). Histopathology of the spinal cord of these horses identified 10 neurologically significant compressive lesions. Myelography and CECT were both able to demonstrate all 10 spinal cord compressive lesions, but myelography falsely identified 2 sites and CECT falsely identified 1 site as compressive lesions of the spinal cord which were not supported by histopathology. Additional qualitative information was obtained by CECT regarding the source, severity and location of spinal cord compression. Computed tomography identified stenosis of the vertebral canal with circumferential loss of contrast agent and documented lateral compressive lesions of the spinal cord due to malformed articular facets. Compression of the peripheral nerve roots by malformed articular facets encroaching on the intervertebral foramen was easily identified by CECT in the axial plane. No compressive lesions were identified in 3 unaffected horses by either method. Minimum sagittal diameter (MSD) values obtained from CECT images were strongly correlated with necropsy measurements, validating CECT as an accurate method of obtaining MSD values. The MSD values in the CSM-affected horses were significantly narrowed (P less than 0.05) from C3C6 regardless of the site of spinal cord compression, when compared with the unaffected controls. This finding supports previous reports suggesting that generalised stenosis of the vertebral canal is an important feature in the pathogenesis of cervical stenotic myelopathy.