Malignant Sertoli Cell Tumour in a Young Simmenthal Bull – Clinical and Pathological Observations

Tumours are rare in the bovine testicle. A case of malignant Sertoli cell tumour in a 29‐month‐old Simmenthal bull that was hospitalized with a history of severe unilateral scrotal swelling is reported. On inspection and palpation, the scrotal sac was found enlarged with fluctuant content in the right side. The right testicle was enlarged, hard and indolent. Also the right plexus pampiniformis and funiculus spermaticus were enlarged. Sonograms revealed severe changes in the right testicle with a loss of homogeneity and multiple hyperechogenic areas. After slaughter, the scrotum with testicles were removed and evaluated pathologically. On section, the right testicle contained areas of necrosis, haemorrhage, and mineralization. Histology showed Sertoli cells in tubular structures surrounded by dense fibrous stroma replacing normal testicular tissue. Both lymphatic and blood vessels were infiltrated by neoplastic cells. Immunohistochemically, the neoplastic cells stained positive for vimentin and negative for cytokeratin and S‐100. Based on the pathological observations a diagnosis of right‐sided malignant Sertoli cell tumour with vascular invasion and hydrocele was established.     

A clinical trial of a topical preparation of miconazole, polymyxin and prednisolone in the treatment of otitis externa in dogs

A topical preparation containing miconazole, polymyxin and prednisolone was shown to be more effective in the treatment of otitis externa in 167 dogs than 2 other ear preparations containing antibiotics, an antimycotic and a corticosteroid. With miconazole, polymyxin and prednisolone, the recurrence rate was 26.7% compared with 72.6% and 54.3% when the other products were used. The mean duration of treatment required to achieve resolution of clinical signs was 9.6 days, compared with 12.2 days and 13.0 days and no cases failed to respond to treatment, compared with 17.7% and 14.3%. Malassezia canis alone (71%) or in association with bacteria (18%) was recovered from 44 of 49 ears cultured.     

Esterase-inhibiting photo-oxidation products from the organophosphorus insecticide pyrimithate

Pyrimithate (2-dimethylamino-6-methylpyrimidin-4-yl diethyl phosphorothio-nate) decomposes when exposed to u.v. light in the presence of air to a complex mixture of products, some of which inhibit esterases directly or indirectly. Separation of the mixture by thin-layer and liquid chromatography gave five pure components in sufficient quantity for spectroscopic identification. A sixth was tentatively identified. The structures ( II-VII ) show that oxidative attack occurs at the dimethylamino group and at the sulphur atom.     

Metabolic aspects of the toxicology of diazinon. I. Hepatic metabolism in the sheep,cow, pig,guinea-pig,rat, turkey,chicken and duck

The phosphorothionate insecticide diazinon was incubated with liver microsomes from the sheep, cow, pig, guinea-pig, rat, turkey, chicken and duck. Metabolism by liver slices of most of these species was also examined. Hydroxydiazinon, isohydroxydiazinon, dehydrodiazinon, their oxons and diazoxon were identified and determined quantitatively or semi-quantitatively. An eighth metabolite was tentatively identified as the 6-aldehyde analogue of diazinon. Yields and rates of production of these metabolites varied greatly between species. Production of oxons was not generally correlated with susceptibility to diazinon poisoning, although it was lowest in the least susceptible animal, the sheep. The degradation of oxons by liver slices was too slow to explain the low toxicity of diazinon to the mammals. The relative importance of hepatic and extrahepatic metabolism in determining toxicity to vertebrates is discussed.     

Comparison of persistence of seven bovine viruses on bovine embryos following in vitro exposure

The ability of seven cytopathic strains of bovine viruses to adhere to the zona pellucida of six-to-eight day-old bovine embryos were compared. Embryos were exposed to virus by placing them either in virus suspensions or by culturing them on infected bovine turbinate cultures for 18-24 h. After exposure to bovine virus diarrhea virus (BVDV), infectious bovine rhinotracheitis virus (IBV), bluetongue virus (BTV), pseudorabies virus (PRV), vesicular stomatitis virus (VSV), parainfluenza 3 virus (PI3), or bovine enterovirus virus (BEV), the embryos were tested for virus by culture in bovine turbinate cells and by morphological examination using electron microscopy (EM). A special technique to minimize loss of embryos processed for EM was developed. More embryos had viral particles on the surface of the zona pellucida after exposure to 18-24 hour infected cell cultures than did embryos exposed to viral culture suspensions. The most dramatic finding was that BTV adhered in large numbers to the surface of the zona pellucida of exposed embryos. IBRV, PRV, and VSV comprised an intermediate group, with virions occasionally detected on the surface of exposed embryos after 5 washes. Therefore, extensive washing is required. The PI3 and BEV were easily removed from embryo-exposed virus by washing. BVD was difficult to identify morphologically, making assessment by EM unreliable. There was no evidence that any one of the seven viruses penetrated the intact zona pellucida. Using a micromanipulator, 42 embryos were also directly inoculated through the zona pellucida with +/- 50 picoliters of virus inoculum or medium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Feasibility of using retinol-binding protein from capillary blood specimens to estimate serum retinol concentrations and the prevalence of vitamin A deficiency in low-resource settings

Vitamin A deficiency (VAD) is a significant public health problem in many countries. While cost-effective interventions are available to control VAD, reliable information is needed to the track progress of control programmes. However, assessment of VAD is uncommon because current approaches are expensive and not feasible in low-resource settings. The present study explores the utility of retinol-binding protein (RBP), analysed by enzyme-linked immunosorbent assay from capillary blood, as an alternative measure of serum retinol concentrations in populations. The study collected matched panels of venous and capillary blood from pre-school children in Chiang Mai, Thailand. Of a total sample of 195 children, there were no differences between RBP from venous blood, RBP from capillary blood or retinol from capillary blood relative to retinol from venous blood. Receiver-operating characteristic curve analysis suggested a cut-off of RBP < 0.825 micromol l(-1) had optimal screening proficiency relative to retinol <0.70 micromol l(-1). For the purpose of population assessment, all three parameters performed well in screening for VAD relative to retinol from venous blood. There were no differences in the estimates of VAD between children stratified by inflammation status. Lower RBP concentrations were found in children in the early convalescent stage of infection than in children with no infection or in the late convalescent stage. This study provided evidence of the biological comparability between retinol and RBP estimated from venous blood and capillary blood. This is a critical observation as it provides empirical evidence that RBP from capillary blood is a surrogate measure of serum retinol concentrations.