Monoclonal antibody (MAb) against Mycoplasma gallisepticum strain PG31 was produced in BALB/c mice. The MAb (designated M9) was of IgG3 isotype and reacted with an epitope in M gallisepticum antigens with molecular weights of 35, 90, 95, and 98 kilodaltons (kDa). The M9 reacted with M gallisepticum antigens in the dot-blot ELISA and in western blot assays. It agglutinated M gallisepticum strains PG31, F, R, S6, A5969, and 9 field isolates from various sources. A coagglutination assay, using Staphylococcus aureus (Cowan strain 1), was developed to enhance the agglutination of some weakly agglutinating M gallisepticum isolates. The M9 did not react with M synoviae, M iowae, M meleagridis, M gallinarum, or M gallinaceum in any of the aforementioned assays. This MAb may be useful in facilitating laboratory diagnosis of M gallisepticum infections.

Conjunctiva-associated lymphoid tissue (CALT) in the eyelids of chickens was studied by gross, histologic, and electron microscopic techniques. Structural features were characterized at 1 day of age and at posthatching week (PHW) 1, 2, 3, 4, 6, 8, 12, and 16. Beginning at PHW 1, prominent lymphoid nodules containing a heterogenous population of lymphocytes, lymphoblasts, and macrophages were first observed within conjunctival folds and fissures of the lower eyelid. Nodules contained germinal centers by PHW 2 and plasma cells by PHW 4. The epithelium associated with these nodules was flat, had short, irregular microvilli, contained intraepithelial lymphocytes, and lacked goblet cells. High endothelial venules were located at the base of lymphoid nodules and contained lymphocytes within and below the cuboidal endothelium. In the upper eyelid, CALT was morphologically similar to lymphoid tissue in the lower eyelid, but nodules were smaller and more random, lacked association with epithelial folds and fissures, and were clustered around the opening of the nasolacrimal duct. By PHW 12, CALT was characterized by basal germinal centers outlined by collagenous stroma, suprafollicular plasma cells, columnar epithelium with goblet cells, and fewer intraepithelial lymphocytes. On the basis of these features, CALT in chickens has morphologic characteristics similar to other components of the mucosal immune system and, therefore, may have a role in mucosal immunity.

A rapid, simple chemosensitivity assay, assessing tumor cell nuclear uptake of doxorubicin hydrochloride, was evaluated in 16 dogs with appendicular osteosarcoma. Doxorubicin was administered to dogs in 5 biweekly treatments, and surgical resection was performed after the second or third treatment, The chemosensitivity assay was performed on biopsy specimens from all dogs before chemotherapy. It was repeated on tissue from resected tumors, and tumors were evaluated histologically to determine the degree of necrosis resulting from chemotherapy. Disease-free and total survival time correlated significantly (P < 0.05 in both cases) with the degree of postchemotherapy necrosis of the primary tumors. Significant correlation was not apparent between the percentage of tumor cells with nuclear uptake of doxorubicin (in either biopsy or resection samples) and disease-free or total survival time. The percentage of cells with nuclear uptake of doxorubicin in surgically resected tumors correlated significantly (P < 0.05) with percentage of necrosis,

The bulbospongiosus reflex, genitoanal reflex, and nerve conduction velocity of the dorsal nerve of the penis were evaluated in cats. Seven adult sexually intact or castrated male mixed-breed cats underwent surgical isolation of the bulbospongiosus (analagous to bulbocavenosus) branch, anal branch, and distal trunk of the pudendal nerve. The bulbospongiosus and genitoanal reflexes were recorded from the bulbospongiosus and anal branches, respectively, by electrical stimulation, in turn, of the distal pudendal trunk and the penis itself. Nerve conduction velocity of the dorsal nerve of the penis was calculated by measuring response latency differences in the anal branch after stimulation of 2 sites on the extruded penis. The bulbospongiosus reflex had response latencies of 8.1 to 10.3 ms (distal trunk stimulation) and 11.0 to 13.0 ms (penile stimulation). The genitoanal reflex had latencies of 8.1 to 10.5 ms (distal trunk stimulation) and 11.2 to 13.2 ms (penile stimulation). Response amplitudes diminished at stimulus rates of 5 to 10 Hz; responses were abolished at rates of 12 to 15 Hz, suggesting that the reflexes are polysynaptic. There was no significant difference between latency values for the bulbospongiosus and genitoanal reflexes. Mean +/- SD nerve conduction velocity in the dorsal nerve of the penis was calculated to be 3.8 +/- 0.34 m/s, which was considerably slower than that found in human beings. This may represent technical difficulties in performing the test in cats, but could also indicate a difference between cats and human beings in the predominant population of cutaneous sensory fiber types of the penis.

Ticlopidine hydrochloride was evaluated for its effectiveness in inhibiting platelet aggregation and serotonin release in 5 laboratory Beagles before and after heartworm implantation with 7 adult Dirofilaria immitis, and after embolization with 7 dead heartworms to mimic what happens after heartworm adulticide treatment. Five other laboratory Beagles, similarly implanted and embolized with heartworms, were used as nonmedicated controls. During the heartworm-negative stage, the dosage of ticlopidine that inhibited adenosine diphosphate (ADP)-induced platelet aggregation in 5 dogs by at least 50% after 5 days of treatment was 62 mg/kg of body weight once a day. In the same dogs implanted with 7 adult heartworms 21 days previously, mean (+/- SD) ticlopidine dosage required to obtain similar results was 71 (+/- 13) mg/kg given once daily. During the 21 days after dead heartworms were implanted in heartworm-infected dogs, mean ticlopidine dosage was 108 (+/- 35) mg/kg (range, 62 to 150 mg/kg). Ticlopidine treatment was associated with increased platelet numbers in all 5 dogs during the heartworm-negative stage and in 4 of 5 dogs during the heartworm implantation and heartworm embolization stages. Mean platelet volume tended to decrease as platelet numbers increased. At necropsy, gross and histologic pulmonary lesions were less severe in ticlopidine-treated dogs than in nonmedicated control dogs.

To determine the position, dimensions, and structure of the right kidney in cattle by use of ultrasonography, the right kidney of 11 healthy Brown Swiss cows was examined 10 times within 2 weeks. A 3.5- and 5.0-Mhz linear and convex transducer was placed on the right side of the cow in the lumbar region, in the paralumbar fossa, and in the last intercostal space. The echogenicity of various renal structures differed. The lobulation of the kidney in cattle could be visualized ultrasonographically; however, the cortex and medulla could not be differentiated. The distance between body surface and the right kidney was almost 3 times larger (5.3 +/- 1.71 cm, mean +/- SD) in the lumbar region than in the paralumbar fossa (1.8 +/- 0.52 cm). The vertical diameter of the kidney was remarkably smaller (5.1 +/- 0.47 cm) than the horizontal diameter (9.4 +/- 0.98 cm). In 7 cows, the thickness of the renal cortex and medulla was between 1.9 and 2.1 cm. The medullary pyramids could be visualized when the transducer was placed in the paralumbar fossa. Fourteen of 19 variables measured had a coefficient of variation between 8 and 14%. It was concluded that the ultrasonographic values determined in this study can be used as references for the diagnosis of morphologic changes in the right kidney of domestic dairy cattle.

Hydrated sodium calcium aluminosilicate (HSCAS), an anticaking agent for agricultural feeds, was added to aflatoxin (AF)-contaminated diets of 3 lactating dairy cows and evaluated for its potential to reduce aflatoxin M1 (AFM1) residues in milk. During phase I, cows were fed alternating diets that consisted of 200 microgram of AF/kg of feed for 7 days, 0.5% HSCAS plus 200 microgram of AF/kg of feed for 7 days, and feed with the HSCAS removed for a final 7 days. The AFM1 milk concentrations from the intervals with HSCAS added to diets were compared with those times when HSCAS was absent. The presence of 0.5% HSCAS in feed containing 200 microgram of AF/kg reduced AFM1 secretion into the milk by an average of 0.44 microgram/L (from pretreatment of 1.85 microgram/L to 1.41 microgram/L with HSCAS, a 24% reduction). Following a 10-day period of noncontaminated feed consumption and no AFM1 residues in the milk, phase II of the study was begun. The same experimental design as phase I was used, but the dosages of HSCAS and AF were changed to 1.0% and 100 microgram/kg of feed, respectively. The addition of 1.0% HSCAS in feed containing 100 microgram of AF/kg decreased AFM1 content in the milk by an average of 0.40 microgram/L (from a pretreatment of 0.91 microgram/L to 0.51 microgram/L when HSCAS was present, a 44% reduction). These findings suggest that HSCAS, a high-affinity sorbent compound for AF in vitro, is capable of reducing the secretion of AFM1 into milk.

Campylobacter jejuni A74/O and A74/C are congenic strains. An oral dose of 10(5) organisms of strain A74/C colonizes chicken intestines. Strain A74/O, from which A74/C is derived, does not colonize the chicken intestines with an oral dose of 10(5) organisms. In this study, the congenic bacteria were compared to identify possible colonization mechanisms. Differences were not observed in plasmid content or by HindIII, Pst I, Acc I, HincII, Ava I, Ava II, Xba I, and BamHI restriction enzyme digestion of total DNA. Transmission electron microscopy of negatively stained samples revealed no differences between the strains. Sections of cecal tissue from nonfed day-of-hatch chicks were cultured with each strain for 2 hours and then examined by light and electron microscopy. Both strains caused necrosis of villus epithelial cells. Immunofluorescent or silver staining revealed strain A74/C located deep in numerous epithelial crypts, but strain A74/O only was present in one sample mixed with sloughed necrotic cells. Similarly, organisms were detected by transmission electron microscopy deep in crypts in tissues cultured with A74/C, but not A74/O. Cells of A74/C detected in crypts did not appear to associate with epithelial cells. The strains did not differ in chemotactic behavior to mucin or fucose.

Pathophysiologic effects of Ostertagia ostertagi infection and their prevention by strategic anthelmintic treatments were studied in 3 groups each of 6 steer calves. Group-1 calves were noninfected controls. Group-2 calves were inoculated with 100,000 third-stage larvae on the 1st and 28th days of the experiment and grazed on pasture initially free of contamination. Group-3 calves were on a similar regimen as those in group 2, but were also treated with ivermectin 9 days after each larval inoculation. Group-2 calves had increased plasma pepsinogen and gastrin values and decreased weight gains, and total serum protein and albumin concentrations from the 2nd week of infection onward. They were anemic at 10 to 12 weeks and had lower carcass and meat quality at slaughter. Strategic anthelmintic treatments were effective in preventing these effects and calves in groups 1 and 3 had similar performances. On the basis of our findings, high pepsinogen values were related to worm burdens, whereas high gastrin concentrations were related to gastric lesions.

A cross-sectional epidemiologic study associating air quality with swine health was conducted on 28 swine farms in southern Sweden. Correlation of housing air environment to swine diseases and productivity (data collected over the preceding 12 months) were investigated. The most prevalent swine health problems detected at slaughter were pneumonia and pleuritis. In farrowing and nursery operations, the most prevalent problem was neonatal pig mortality. Several air contaminants (dust, ammonia, carbon dioxide, and microbes) were found to be correlated with these swine health problems. Maximal safe concentrations of air contaminants were estimated on the basis of dose-response correlation to swine health or human health problems. Recommended maximal concentrations of contaminants were: dust, 2.4 mg/m3; ammonia, 7 ppm; endotoxin, 0.08 mg/m3; total microbes, 10(5) colony-forming units/m3; and carbon dioxide, 1,540 ppm. The overall quality of the ventilation system was correlated with lower concentration of ammonia, carbon dioxide, microorganisms, and endotoxin, but not with dust concentrations. High animal density was related to high ammonia and air microbe concentrations. Animal density measured as kilograms of swine per cubic meter (compared with kilograms of pig weight or swine per square meter) had the highest correlation to animal health and air contaminants.