Ethionine, an analogue of methionine, induces fatty liver in rats by inhibiting protein synthesis, including that of apolipoproteins in liver. Ethionine was administered to cows to elucidate the participation in fatty liver development of impaired triglyceride secretion from liver attributable to decreased apolipoprotein synthesis. The administration resulted in a significant increase of liver triglyceride contents. Several apolipoproteins were found to have decreased concentrations. In particular, apolipoprotein B-100 in very low-density (0.95 to 1.006 g/ml) lipoprotein and in low-density (1.006 to 1.063 g/ml) lipoprotein fractions was greatly reduced. The decreases of apolipoprotein B-100 concentrations in the 2 lipoprotein fractions were at least partly correlated to the decreased triglyceride concentrations in the respective fractions. Decreased concentrations of apolipoprotein A-I in high-density (1.063 to 1.210 g/ml) lipoprotein were also observed, although not as distinctly as with apolipoprotein B-100. Total cholesterol and phospholipid concentrations in low- and high-density lipoprotein fractions were decreased. The decrease in cholesterol was attributed to reduced concentrations of cholesteryl esters. It was suggested that the impaired lipid secretion from liver attributable to the decreased apolipoprotein concentrations has a role in ethionine-induced fatty liver of cows.

Maximal urethral closure pressure, functional profile length, and number of respiratory peaks on the resting urethral pressure profile, expressed as a percentage of those occurring on the bladder pressure recording, were compared at catheter withdrawal speeds of 1 and 3 mm/s in 30 anesthetized bitches. Significant (P < 0.001) differences were found in maximal urethral closure pressure and percentage of transmission of respiratory peaks between the 2 speeds. Significant difference was not detected in functional pro-file length.

We attempted to define quantitative objective criteria for diagnosis of mammary adenoma and adenocarcinoma in dogs. To that end, correlation between diagnosis made by conventional histologic examination and morphometric descriptors, obtained by computerized histologic analysis, was assessed in biopsy specimens of mammary tissue from 63 dogs. We used 2 interactive computer procedures: one assessed mean nuclear perimeter, mean nuclear area, and circularity factor; and the other evaluated nuclear stratification and cell crowding. A data base was generated with 11 specimens from normal mammary tissue, 17 specimens from mammary adenoma, 18 specimens from low-grade mammary adenocarcinoma, and 15 specimens from mammary adenocarcinoma. The mean values of nuclear perimeter, nuclear area, nuclei per millimeter of basement membrane, and minimal distances from cells to basement membrane gradually increased from normal to high-grade malignancy. Distributions of nuclear areas and of minimal distances from cells to basement membrane were shifted in specimens from malignant tumors. Multivariate analysis confirmed the homogeneity of the diagnostic groups.

Tooth root and root trunk surface area measurements were taken from 20 first mandibular molar (M1) teeth obtained randomly from canine cadaver specimens. The mean root surface area for all teeth was 497.1 +/- 116.2 mm2. The cumulative surface areas of the mesial (MR) and distal (DR) roots were 251.4 +/- 70.2 mm2 and 211.7 +/- 51.9 mm2, respectively. The root trunk surface area was 34.0 +/- 21.4 mm2. Surface area measurements for individual roots and the root trunk were significantly different. Cumulative individual root surface area (MR + DR) was 93.2% of total root surface area. The MR surface area contributed most to total root surface area (50.6%) and cumulative individual root surface area (54.3%). The mean distance from the beginning of the root trunk to the furcation was 2.1 mm. On the basis of the linear variation of the percentage of root surface area of the M1, 44.6% of the total root surface area was 3 to 7 mm apical to the most coronal aspect of the cementoenamel junction. The MR was heart-shaped, compared with the more cylindrical shape of the DR.

The effect of dietary copper deficiency on T-cell mitogenic responsiveness and phenotypic profile of blood mononuclear cells (MNC) in weaned pigs was examined. Outbred, weaned pigs were fed a semipurified diet containing adequate (6.4 mg/kg of body weight) or deficient (0.8 mg(kg) amounts of Cu. Pigs fed the low Cu diet for 10 weeks had markedly decreased concentrations of Cu in liver and plasma, and hypertrophic hearts. In vitro reactivity of MNC from Cu-deficient pigs to phytohemagglutinin and concanavalin A was significantly suppressed. This functional impairment was not associated with a decrease in the percentages of T cells, CD4 or CD8 cell subsets, or B cells. Expression of SLA-DQ and SLA-DR class II major histocompatibility complex (MHC) antigens was increased by Cu deficiency, the former significantly. Unlike rodents, in which inadequate Cu nutriture induces functional T cell deficiency that is associated with a decrease in the CD4 T-cell subset, swine fed inadequate Cu diets for 10 weeks had no changes in MNC subsets yet clearly manifested functional impairment of T-cell responses.

The effect of metoclopramide (MC), a dopamine antagonist on luteinizing hormone (LH), was examined in anestrous primaparous cows. Metoclopramide has been found to be beneficial in overcoming fescue toxicosis; increasing LH secretion stimulates return to ovulatory function after parturition. Consequently, if MC had negative effect on LH secretion, it would indicate that administration of MC to reproducing animals might be limited. Of 14 postpartum (47 to 66 days) cows, 7 were given MC (4 mg/kg of body weight, IV), and 7 served as controls. Blood was obtained via jugular cannulas at 15-minute intervals for 8 hours; MC was given at the end of the first hour, and gonadotropin-releasing hormone (GnRH, 7 mg/kg), was given IV at the end of hour 7 as a challenge stimulus for LH secretion. Prior to GnRH administration, MC did not have significant effect on LH secretion, as judged by mean serum LH concentration, LH pulse frequency, and LH pulse amplitude. Administration of MC resulted in greater (P < 0.05) LH response to GnRH, indicating enhanced secretory ability when the pituitary gland was challenged. Serum prolactin concentration was increased (P < 0.01) by MC administration. Therefore, MC did not have adverse effect on LH secretion in postpartum cows.

Two hundred sixty Haemophilus spp isolates that had been obtained from the respiratory tract and other sites of swine were acquired from diagnostic laboratories, primarily in the United States and Canada. The majority of isolates (243/260) were biochemically characterized as H parasuis; however, a few isolates of taxa distinct from H parasuis (taxa "minor group," D, E, and F) were identified. Fourteen H parasuis serovars were identified, and of those previously described, the most prevalent were 5 (24.3% of isolates), 4 (16.1%), 2 (8.2%), and 7 (3.7%). Three new serovars that were also prevalent included ND4 (11.1%), ND3 (8.6%), and ND5 (6.6%). Serovars 1, 3, 6, C, D, and new serovars ND1 and ND2 were infrequently identified, and 15.2% of isolates were nontypeable. It was not uncommon to isolate multiple serovars from swine of the same herd or related herds. Distribution of serovars among isolates from the United States and Canada was generally similar; however, a higher prevalence of serovar 5 and a lower prevalence of serovars 2, ND3, and ND5 were evident in isolates from Canada. Comparison of isolates obtained from the respiratory tract of swine without polyserositis with those obtained from swine with polyserositis revealed an increased frequency of serovars 4 and 5, and a decreased frequency of serovar 2, among isolates from swine with polyserositis. However, all prevalent serovars were isolated from swine with polyserositis, and data were not indicative of an association between serovar, site of isolation, or pathogenic potential.

Protein concentration was determined, using the Bradford technique, in tears from cats with normal corneas and from cats with corneal sequestrum. Tears from the former group contained 5.81 +/- 2.29 mg of protein/ml; those from cornmeal sequestrum-affected cats contained 6.21 +/- 2.21 mg/ml. Difference between the 2 values was not significant. Molecular weight determination was made, using 4 to 20% sodium dodecyl sulfate-polyacrylamide gels. Molecular mass of proteins ranged from 263 to 14 kDa. There was no detectable difference in the band patterns for the 2 groups.

Serum concentrations of metronidazole were determined in 6 healthy adult mares after a single IV injection of metronidazole (15 mg/kg of body weight). The mean elimination rate (K) was 0.23 h(-1), and the mean elimination half-life (t1/2) was 3.1 hours. The apparent volume of distribution at steady state was 0.69 L/kg, and the clearance was 168 ml/h/kg. Each mare was then given a loading dose (15 mg/kg) of metronidazole at time 0, followed by 4 maintenance doses (7.5 mg/kg, q 6 h) by nasogastric tube. Metronidazole concentrations were measured in serial samples of serum, synovia, peritoneal fluid, and urine. Metronidazole concentrations in CSF and endometrial tissues were measured after the fourth maintenance dose. The highest mean concentration in serum was 13.9 +/- 2.18 microg/ml at 40 minutes after the loading dose (time 0). The highest mean synovial and peritoneal fluid concentrations were 8.9 +/- 1.31 microg/ml and 12.8 +/- 3.21 microg/ml, respectively, 2 hours after the loading dose. The lowest mean trough concentration in urine was 32 microg/ml. Mean concentration of metronidazole in CSF was 4.3 +/- 2.51 microg/ml and the mean concentration in endometrial tissues was 0.9 +/- 0.48 microg/g at 3 hours after the fourth maintenance dose. Two mares hospitalized for treatment of bacterial pleuropneumonia were given metronidazole (15.0 mg/kg, PO, initially then 7.5 mg/kg, PO, q 6 h), while concurrently receiving gentamicin, potassium penicillin, and flunixin meglumine IV. Metronidazole pharmacokinetics and serum concentrations in the sick mares were similar to those obtained in the healthy mares.

The anatomy of the nasolacrimal duct of llamas was examined grossly and radiographically in 2 llamas. Dacryocystorhinography was performed on cadaver heads, using a radiographic aqueous contrast agent. Anatomic casts of the nasolacrimal apparatus were obtained by cannulation of the duct and use of polyurethane cast material. Dacryocystorhinography accurately revealed the nasolacrimal apparatus and compared favorably with gross dissections and polyurethane casts.