West Nile virus-infected human dendritic cells fail to fully activate invariant natural killer T cells.

West Nile virus (WNV) infection is a mosquito-borne zoonosis with increasing prevalence in the United States. WNV infection begins in the skin, and the virus replicates initially in keratinocytes and dendritic cells (DCs). In the skin and cutaneous lymph nodes, infected DCs are likely to interact with invariant natural killer T cells (iNKTs). Bidirectional interactions between DCs and iNKTs amplify the innate immune response to viral infections, thus controlling viral load and regulating adaptive immunity. iNKTs are stimulated by CD1d-bound lipid antigens or activated indirectly by inflammatory cytokines. We exposed human monocyte-derived DCs to WNV Kunjin and determined their ability to activate isolated blood iNKTs. DCs became infected as judged by synthesis of viral mRNA and Envelope and NS-1 proteins, but did not undergo significant apoptosis. Infected DCs up-regulated the co-stimulatory molecules CD86 and CD40, but showed decreased expression of CD1d. WNV infection induced DC secretion of type I interferon (IFN), but no or minimal interleukin (IL)-12, IL-23, IL-18 or IL-10. Unexpectedly, we found that the WNV-infected DCs stimulated human iNKTs to up-regulate CD69 and produce low amounts of IL-10, but not proinflammatory cytokines such as IFN-γ or tumour necrosis factor (TNF)-α. Both CD1d and IFNAR blockade partially abrogated this iNKT response, suggesting involvement of a T cell receptor (TCR)-CD1d interaction and type I interferon receptor (IFNAR) signalling. Thus, WNV infection interferes with DC-iNKT interactions by preventing the production of proinflammatory cytokines. iNKTs may be a source of IL-10 observed in human flavivirus infections and initiate an anti-inflammatory innate response that limits adaptive immunity and immune pathology upon WNV infection.

Experimental Isospora suis infections in miniature swine.

Clinical responses to experimental Isospora suis infections were compared in Sinclair miniature pigs and cross-bred conventional pigs. Pre-patent periods, fecal consistencies, oocyst excretion dynamics, trends in surviving pig weights and lesions were similar in infected miniature and conventional pigs. The results indicate that the susceptibility of miniature pigs to I. suis is similar to that of conventional pigs. These findings should encourage their use as models for the study of neonatal coccidiosis.

Preliminary implications of B-mode ultrasonography of the testicles of beef bulls with normal breeding soundness examinations.

Four polled Hereford bulls were found to have satisfactory breeding soundness examinations. They were examined by B-mode ultrasonography, at which time the testicular diameter was measured by ultrasound. The testicles were removed, measured physically and this data was compared with the ultrasound measurements and correlated with other parameters of the breeding soundness examination. The testicles from bulls with normal breeding soundness examinations appeared ultrasonographically identical with the normal testicles from other species such as the pig and dog. Results indicated that the bull testicle diameter could be accurately measured by ultrasonography. Neither ultrasonographic nor physical testicular diameter measurements correlated statistically with scrotal circumference, but they did correlated well with testicular circumference, weight and volume.

Embryo transfer from goats seropositive for caprine arthritis-encephalitis virus.

Twelve attempts were made to isolate caprine arthritis-encephalitis virus (CAEV) from the uterine flushings of serologically positive superovulated does mated to serologically positive bucks. Embryos were transferred to eight serologically negative estrus-synchronized recipient does and the recipients were monitored serologically following embryo transfer. Virus isolation was attempted from colostrum and placental tissues from does that kidded following embryo transfers and the surviving kid was monitored serologically until four months of age. The CAEV was not isolated from any of the uterine flushings, colostrum or placental tissues. All recipients and the kid remained seronegative throughout the trial.

Caliper and ultrasonographic measurements of bovine testicles and a mathematical formula for determining testicular volume and weight in vivo.

This study quantified the relationship between calibrated caliper and ultrasonographic derived measurements of bovine testicles in vivo with actual testicular length, width, volume and weight. The prolate spheroid formula was tested to accurately predict testicular volume and a modification to predict weight. Ten bulls were employed to derive caliper and ultrasound testicle (n = 20) length and width measurements in vivo. Caliper length measurements were more reliable than ultrasound derived lengths, with correlations of r2 = 0.8023; P < 0.05 and r2 = 0.5111; P < 0.05, respectively. Width for both the calipers and ultrasound measurements when compared to actual width measurements were r2 = 0.7313; P < 0.05 and r2 = 0.8310; P < 0.05, respectively. The prolate spheroid formula is reliable in determining testicle (n = 116) volume (r2 = 0.8928; P < 0.05). Testicular volume and weight are highly correlated (r2 = 0.9776; P < 0.05); therefore, a modification of the prolate spheroid formula was used to predict weight (r2 = 0.9084; P < 0.05) against the actual weight. Caliper-derived length and width measurements used in the prediction of volume and weight had correlation coefficients against actual volume and weight of r2 = 0.5497; P < 0.05 and r2 = 0.6340; P < 0.05, respectively. Ultrasound in vivo measurements for prediction of testicular volume and testicular weight had a correlation of r2 = 0.3276; P < 0.05 and r2 = 0.6249; P < 0.05, respectively. A testicular (n = 116) length to width ratio of 1.8:1 (SEM = 0.01) was determined for both slaughterhouse and castrated animals. Caliper measurements are reliable, inexpensive and much simpler to obtain than ultrasound determinations for in vivo testicle length, width, volume and weight. The two-dimensional measurement of length and width would be a more accurate predictor of testicle volume and weight than the one-dimensional measurement of scrotal circumference (SC), especially in bulls with variation in testicular shape.

Campylobacter jejuni infections in gnotobiotic pigs.

At 3 days of age, 12 gnotobiotic pigs were inoculated orally with broth cultures of Campylobacter jejuni. One pig was euthanatized and evaluated each day for 12 days. In the cecum and colon, there was diffuse edema, neutrophilic infiltration, and sloughing of epithelial cells from the mucosa on postinoculation days (PID) 2 through 5. Dysplastic colonic crypt epithelial cells were observed in the submucosa of the colon on PID 5 through 12. Curved, rod-shaped bacteria were detected on the surface of ileal, cecal, and colic absorptive and glandular epithelial cells. Bacteria also were found around small submucosal vessels on PID 3 and 4 and were associated with numerous perivascular neutrophils. The gnotobiotic pig appears to provide a simple, well-controlled in vivo model for the study of the pathogenesis of C jejuni infections in human beings, pigs, and other mammals.

Evidence for suppression or incomplete maturation of cell-mediated immunity in neonatal calves as determined by delayed-type hypersensitivity responses.

Fifteen bovine fetuses were inoculated in utero 20 to 123 days before birth with a mixture of killed Mycobacterium bovis, tetanus toxoid, and ferritin in Freund's complete adjuvant. On the day of birth (day 0) and when the calves were 21 days of age, the calves were skin-tested to each of the antigens for delayed-type hypersensitivity. Nine delayed-type hypersensitivity responses to the various antigens were obtained at the 0-day test, whereas 28 responses were obtained at the 21-day test. Of those responses that were positive, the mean differences in the double skin-fold thickness before testing and 48 hours later were 5.4 mm for the 0-day and 21-day test and 9.4 mm for the 21-day test. Six control calves that were not inoculated in utero were skin tested on days 0 and 21 and did not exhibit any positive reactions. There was no indication that the interval between immunization and birth had any effect on the immune response. Cellular characteristics of the reactions at 0 and 21 days were the same.

Ultrasonographic evaluation of normal boar testicles.

The testicles of 14 Landrace boars (7 at 9 months of age and 7 at 15 months of age) were measured and examined by routine physical examination. Semen analysis was done. The testicles were then examined and measured by B-mode ultrasonography. The ultrasonographic appearance and measurements were compared with the physical measurements and the semen analysis. Seminiferous epithelial area (SEA) data were obtained after the testicles were surgically removed. These data were compared with the ultrasonographic data and the other physical data. A correlation could not be found between semen analysis and either physical or ultrasonographic data or between SEA data and semen analysis. Significant differences were found between the 9-month-old and the 15-month-old boars relative to 5 measurements: SEA, tunica albuginea thickness, testicular diameter, testicular length, and epididymal diameter. A ratio of 4:1 was found between each of the average physical measurements (scrotal diameter, testicular-epididymal circumference, testicular-epididymal length) and ultrasonographic measurements of testicular diameter. A ratio of 2.6:1 was found between testicular diameter and epididymal tail diameter (cranial to caudal).

Effectiveness of two commercial infectious bovine keratoconjunctivitis vaccines.

Two commercially available infectious bovine keratoconjunctivitis (IBK) vaccines were evaluated for their effectiveness in protecting cattle from disease caused by experimental challenge exposure and natural transmission of Moraxella bovis infections. The study was conducted as 2 experiments, using a total of 81 cattle that were culture-negative for M bovis prior to vaccination. In each experiment, young adult cattle were randomly allotted to 4 groups. Each calf in groups 1 and 2 was vaccinated according to the vaccine manufacturer's directions. Groups 3 and 4 were unvaccinated controls. Three weeks after the last vaccination, each calf in groups 1 and 3 was experimentally challenge exposed by dropping a suspension of viable cells of a virulent strain of M bovis directly onto the corneal surface of each eye. Calves in all 4 groups were then commingled in open pastures so that calves in groups 2 and 4 could be naturally exposed to the calves with experimentally induced infections. Each calf was examined for signs of ocular disease on a regular basis by 2 experienced clinicians who scored each eye for severity of disease on the basis of a prearranged scale. Neither clinician was aware of the vaccination or exposure status of the calf nor to which experimental group they belonged. Lacrimal secretions were collected regularly to determine the number of eyes in which the virulent organism became established. Moraxella bovis with bacterial cultural characteristics similar to those of the virulent strain placed in the eyes of groups 1 and 3 was cultured from greater than or equal to 83% of the eyes of calves in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortions, fetal death, and stillbirths in pregnant pygmy goats inoculated with tachyzoites of Neospora caninum.

Neospora caninum-induced abortion is a major production problem in the dairy cattle industry in the United States and worldwide. Abortions attributable to naturally acquired N caninum infection also have been observed in pygmy goats. We studied experimentally induced infections with N caninum in pregnant pygmy does to determine whether abortions attributable to N caninum infection would occur after inoculation. Seven pregnant pygmy does (1 control doe and 6 inoculated with N caninum) were studied. The control doe remained clinically normal throughout the study and delivered 2 healthy kids. Abortion, fetal death, and stillbirths were observed in some pregnant does inoculated with N caninum. Two pregnant pygmy does inoculated with N caninum early in gestation (day 51) had fetuses that died and were aborted, or died and were reabsorbed. Neospora caninum tachyzoites and lesions were observed in the brain, spinal cord, and heart of aborted fetuses; parasites also were isolated from the placenta. Four additional pregnant pygmy does (2 inoculated at mid-gestation [day 85], and 2 at late gestation [day 127]) did not abort after inoculation. However, 1 doe inoculated during mid-gestation delivered a stillborn fetus that had died about 1 week prior to parturition. This kid was congenitally infected with N caninum. Neospora caninum was isolated from the placentas of all inoculated does examined. Neonatal neosporosis was not observed in live-born kids, nor were stages of N caninum isolated from any live-born kid. Does did not undergo abortion or have congenitally infected kids when they were rebred and evaluated for neosporosis.

Periorchitis after tetramisole treatment in bulls implanted with Setaria labiatopapillos.

Thirteen mixed-breed beef bulls, 1 to 4 years old, were used to determine the effect of live and dead filarial nematodes, Setaria labiatopapillosa, placed in the vaginal cavity of the testes. When dead worms were used, granulomatous lesions developed on the tunica vaginalis parietalis in 7 of 8 testes. The lesions were similar to those seen in some clinical cases of periorchitis. Similar lesions developed in 5 of 6 testes after live worms were implanted in the vaginal cavity of the testes and tetramisole (8 mg/kg) was injected subcutaneously 6 days after implantation. When live worms were implanted and tetramisole was not given, lesions developed in 3 of 6 testes. It was concluded that the granulomatous reaction was a local response to dead or killed S labiatopapillosa.

Use of xylazine, butorphanol, tiletamine-zolazepam, and isoflurane for induction and maintenance of anesthesia in ratites.

Anesthetic effects of xylazine, butorphanol, tiletamine-zolazepam, and isoflurane in ratites (9 emus, 3 rheas, 6 ostriches) were determined. Anesthetic treatments included 4 regimens: induction and maintenance of anesthesia with isoflurane, preanesthetic tranquilization with xylazine and butorphanol followed by induction and maintenance of anesthesia with isoflurane, induction of anesthesia with tiletamine-zolazepam and maintenance with isoflurane, and preanesthetic tranquilization with xylazine and butorphanol followed by induction of anesthesia with tiletamine-zolazepam and maintenance with isoflurane. None of the birds developed irreversible adverse effects, but 2 developed brady cardia (1 was treated with atropine and responded) and 2 others developed transient apnea. Intravenous administration of tiletamine-zolazepam produced rapid and smooth induction of anesthesia in adult ostriches.

Mesothelioma in cattle: eight cases (1970-1988)

Over an 8-year period, 8 beef cattle with mesothelioma were admitted to the Auburn University College of Veterinary Medicine and the Louisiana State School of Veterinary Medicine. Diagnosis was confirmed by histologic examination of affected tissues. Five bulls, 1 steer, and 2 cows were affected. Four of the bulls had scrotal swelling; 2 cows and 1 bull had ventral abdominal swelling. The peritoneal cavity was involved in 5 cases, the pleural cavity was affected in 2 cases, and in 2 cases, disease was apparently confined to the vaginal cavity. Of the 8 cattle, 6 died or were euthanatized; only cattle with tumor apparently confined to the vaginal cavity survived.

Anesthesia in sheep with propofol or with xylazine-ketamine followed by halothane.

OBJECTIVE: This study evaluates the clinical usefulness and anesthetic effect of propofol, and compares these effects with those of xylazine-ketamine-halothane anesthesia in sheep. STUDY DESIGN: Prospective, randomized, clinical trial. ANIMALS OR SAMPLE POPULATION: Fourteen healthy adult male sheep. METHODS: Sheep were randomly assigned to two different drug regimens: (1) Bolus injection of propofol (3 mg/kg, intravenously [i.v.]) followed by continuous intravenous infusion and (2) xylazine (0.11 mg/kg, i.v.) and ketamine (2.2 mg/kg, i.v.) for induction followed by halothane anesthesia. Heart rate, respiratory rate, and arterial blood pressures were monitored during anesthesia. Venous blood samples were collected for blood gas analysis. Quality of induction and recovery were also recorded. RESULTS: The average dose of propofol used to induce and maintain anesthesia was 6.63 +/- 2.06 mg/kg and 29.3 +/- 11.7 mg/kg/hr (0.49 +/- 0.20 mg/kg/min), respectively. The duration of propofol anesthesia was 45.3 +/- 13.2 minutes and recovery to standing occurred in 14.7 +/- 5.7 minutes. Sheep receiving xylazine-ketamine-halothane were anesthetized for 35.9 +/- 4.0 minutes and recovery to standing occurred within 28.5 +/- 7.5 minutes. Sheep anesthetized with propofol had a significantly higher heart rate, diastolic blood pressure and Pvo2, and a lower Pvco2 at 30 minutes and lower BE at 15 and 30 minutes than sheep anesthetized with xylazine-ketamine-halothane. CONCLUSIONS: Propofol anesthesia was characterized by a smooth induction, effective surgical anesthesia and rapid recovery which was comparable to anesthesia with xylazine-ketamine-halothane. CLINICAL RELEVANCE: Propofol may be indicated in situations when it is desirable to maintain anesthesia with an intravenous infusion followed by a rapid recovery in healthy sheep.

Use of an enzyme-linked immunosorbent assay for detection of Treponema hyodysenteriae infection in swine.

Discriminate analysis was used to evaluate the enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Treponema hyodysenteriae antibodies in experimentally and naturally infected swine. In trial 1, 26 pigs were randomly divided into three groups (naturally infected, n = 8; experimentally infected, n = 11; and noninfected, n = 7), and samples were collected for 10 weeks. For trial 2, 31 pigs were randomly divided into two groups (naturally infected, n = 22; and noninfected, n = 7), and samples were collected for 20 weeks. Rectal swabs for T. hyodysenteriae isolation were collected daily, and fecal samples for isolation of Salmonella spp. were collected weekly. Serum samples for ELISA evaluation were collected biweekly (trial 1) or weekly (trial 2). Results of discriminate analysis indicated that the ELISA correctly identified 90% or more of the individually infected pigs at prior probabilities of infection ranging from 60 to 90%. The test correctly identified noninfected pigs at a lower rate (61 to 92% range). The mean ELISA titers of naturally infected pigs without clinical signs were not significantly different (P less than 0.05) from the titers of both groups of experimentally infected pigs. Mean ELISA titers of naturally infected pigs without clinical signs were significantly greater than the mean titers of naturally infected pigs with clinical signs. Naturally infected pigs with clinical signs had a mean ELISA titer that was significantly greater than that of noninfected pigs and significantly less than the mean titers of the experimentally infected pigs without clinical signs and the naturally infected pigs without clinical signs.