Characterization of anti-channel catfish MHC class IIbeta monoclonal antibodies

This study characterizes four monoclonal antibodies (mAb) developed against the major histocompatibility complex (MHC) class II beta chain of the channel catfish, Ictalurus punctatus. Immunoprecipitations using catfish clonal B cells revealed that each of these mAbs immunoselected proteins of approximately 32 and 36 kD, which are of the appropriate sizes for MHC class II alpha and beta chains, respectively. Cell distribution studies using a fluorescence-activated cell sorter (FACS) combined with RT-PCR analyses demonstrated that MHC class II beta is expressed at a high density on catfish clonal macrophage, B and T cell lines, on alloantigen stimulated leukocytes, and on lipopolysaccharide-induced B-cell blasts. Collectively, these results demonstrate the potential importance of these antibodies as reagents in future studies dealing with the functional role of MHC class II molecules in immune recognition of self from non-self.     

Comparative studies of the use of some injectable anaesthetic agents in birds

The effect of three injectable drugs and a combination of two of them was compared in birds. The agents were ketamine hydrochloride, xylazine hydrochloride and the steroid mixture alphaxalone-alphadolone. Ketamine and xylazine were used in combination. One hundred and fifty-four species, all maintained by major zoos in the United Kingdom, were involved in the study. The results indicate that the drugs used produced more widely differing effects in the range of species studied than have previously been reported.     

Continuous positive airway pressure administered via face mask in tranquilized dogs

Objective – To evaluate the tolerance of a continuous positive airway pressure (CPAP) mask in tranquilized dogs and compare PaO₂ in arterial blood in dogs receiving oxygen with a regular face mask or CPAP mask set to maintain a pressure of 2.5 or 5 cm H₂O. Design – Prospective, randomized clinical study. Setting – University teaching hospital. Animals – Sixteen client‐owned dogs without evidence of cardiopulmonary disease were studied. Interventions – Eight animals were randomly assigned to each of 2 treatment groups: group A received 2.5 cm H₂O CPAP and group B received 5 cm H₂O CPAP after first receiving oxygen (5 L/min) by a regular face mask. Animals were tranquilized with acepromazine 0.05 mg/kg, IV and morphine 0.2 mg/kg, IM. An arterial catheter was then placed to facilitate blood sampling for pHa, PaO₂, and PaCO₂ determinations before and after treatments. Direct mean arterial pressure, heart rate, respiratory rate, and temperature were also recorded after each treatment. Measurements and Main Results – CPAP administration was well tolerated by all animals. The mean arterial pressure, heart rate, respiratory rate, temperature, PaCO₂, and pHa, did not differ at any time point between groups. Differences were seen in oxygenation; in group A, PaO₂ significantly increased from a mean of 288.3±47.5 mm Hg with a standard mask to a mean of 390.3±65.5 mm Hg with the CPAP mask and in group B, PaO₂ increased similarly from 325.0±70.5 to 425.2±63.4 mm Hg (P<0.05); no differences were detected between the 2 CPAP treatments. Conclusions – In healthy tranquilized dogs noninvasive CPAP is well tolerated and increases PaO₂ above values obtained when using a regular face mask.     

Case of suspected theobromine poisoning in dairy cattle

High-yielding dairy cows collapsed and died displaying signs of a disturbed central nervous system (muscle tremor, convulsion) and a considerably reduced body condition score. An intense diagnostic screening did not allow to confirm a definite diagnosis. Therefore, further analyses including an evaluation of feeds and feeding were initiated. The herd was fed a total mixed ration (TMR) based on corn and grass silage of moderate nutritive value supplemented with various amounts of chocolate chips. In retrospect, the amount of chocolate chips added to the respective TMR batches could not be quantified. These chips were purchased from a company producing bakery and chocolate products for human consumption and added to the silage and therefore to the TMR in order to increase the energy intake of the animals. Because the TMR, which was fed during the time of the incidence, was no longer available, a sample of a later batch of silage was examined. The amount of chocolate chips was quantified (0.44% per fresh matter), and a theobromine analysis was performed in the chocolate chips of the available batch (69.7 mg/100 g fresh matter). Because of the possible link between chocolate intake and observed signs, an immediate cessation of using the chocolate chips was recommended in addition to an optimisation of the TMR, that is an increase of the energy density. Even though the theobromine intake during the time of the incidence is unknown and information about toxicity of theobromine in ruminants is limited, we suspect that the feeding of chocolate in this case caused all signs including the sudden death of the cows. Further reasons are that no differential diagnoses were established and the problems at the farm stopped after removing the chocolate from the TMR.     

Usefulness of subjective ovine milk scores: II. Genetic parameter estimates

Genetic parameters for a subjective milk score given to ewes within 24 h of parturition were estimated to determine the usefulness of milk score as a selection trait to improve milk production, which influences total litter weight weaned. Heritability of milk score and the genetic correlation of milk score with litter weight weaned were estimated by REML separately for four sheep breeds, Rambouillet (n = 1,731), Targhee (n = 1,638), Columbia (n = 1,731), and Polypay (n = 1,129). Litter weight weaned was the total weight of lambs weaned at approximately 120 d of age under a western range production system. Observed heritability estimates for milk score at first parity were moderate and similar among breeds, ranging from 0.18 to 0.32. Heritability estimates adjusted for a binomial distribution of milk scores at first parity were high (Columbia, 0.43; Polypay, 0.35; Rambouillet, 0.50; Targhee, 0.84). Estimates of observed heritability for second-parity milk score were moderate to high, ranging from 0.23 to 0.46. Milk score at first or second parity was genetically correlated with milk score records at maturity (third parity and greater), with estimates ranging from 0.69 to 1.00. Milk score and litter weight weaned were genetically correlated at first or second parity in Rambouillet (r(g) = 1.00) and Targhee breeds (r(g) = 1.00 and 0.61, respectively), but not in the Columbia and Polypay breeds. Estimates of heritability for lifetime records for milk score ranged from 0.16 to 0.26 across breeds. Estimates of genetic correlations of annual lifetime milk score records with litter weight weaned were high (Columbia, 1.00; Polypay, 0.81; Rambouillet, 1.00; and Targhee, 0.77). Repeatability estimates for milk score were similar across breeds, 0.23 for Columbia, Rambouillet, and Targhee ewes and 0.28 for Polypay ewes. Milk score measured at first or second parity may be a good predictor of future potential milking ability. Further, milk score can be used as a selection trait to improve maternal ability for increasing litter weight weaned. The need for increasing ewe milking performance and lamb growth rate at first parity in commercial range sheep production systems may be addressed by selection for milk score at first parity.     

Comparison of core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes for antemortem diagnosis of enzootic bovine lymphosarcoma in cattle

OBJECTIVE: To determine whether antemortem core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes could be used to distinguish between inflammation and lymphosarcoma in cattle. DESIGN: Prospective study. ANIMALS: 25 cattle with enlarged peripheral lymph nodes. PROCEDURES: Antemortem biopsies of the selected lymph nodes were performed with an 18-gauge, 12-cm core needle biopsy instrument. Fine-needle aspirates were performed with a 20-gauge, 4-cm needle. Specimens were analyzed by pathologists who were unaware of clinical findings and final necropsy findings, and specimens were categorized as reactive, neoplastic, or nondiagnostic for comparison with necropsy results. RESULTS: Sensitivity and specificity of core needle biopsy ranged from 38% to 67% and from 80% to 25%, respectively. Sensitivity of fine-needle aspiration ranged from 41% to 53%, and specificity was 100%. Predictive values for positive test results ranged from 77% to 89% for core needle biopsy and were 100% for fine-needle aspiration. Predictive values for negative test results were low for both core needle biopsy and fine-needle aspiration. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that core needle biopsy and fine-needle aspiration can aid in the antemortem diagnosis of bovine enzootic lymphosarcoma. Results of fine-needle aspiration of enlarged peripheral lymph nodes were more specific and more predictive for a positive test result than were results of core needle biopsy.     

Effect of salicylates on intestinal secretion in calves given (intestinal loops) Escherichia coli heat-stable enterotoxin

The inhibitory effect of salicylates on intestinal secretion in 1- to 5-day-old calves given Escherichia coli heat-stable enterotoxin (ST)-induced intestinal fluid response was investigated. Purified ST was diluted in isotonic saline solution to obtain 1:10, 1:25, 1:50, 1:75, and 1:100 dilutions. Each dilution (1 ml) was inoculated into ligated loops in the distal part of the jejunum of each calf. Acetylsalicylic acid (aspirin) given orally (100 mg/kg) at 4 hours before ST was inoculated did not substantially alter the intestinal fluid response to ST. Sodium salicylate (IV) infusion, begun simultaneously when, or at 1 hour after, ST was inoculated, significantly (P less than 0.05) decreased fluid accumulation in those loops inoculated with ST dilutions of 1:25 or greater. The sodium and potassium concentrations of the accumulated fluid did not differ significantly between or within treatment groups. These results indicate that sodium salicylate infusion may be beneficial in treating enterotoxic colibacillosis in calves. Aspirin given orally at the dose used in the present study, would not have any beneficial effect.     

Indigenous protected areas in Sea Country: Indigenous‐driven collaborative marine protected areas in Australia

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