Effects of atropine, isoprenaline, neostigmine and practocol on cardiac arrhythmias induced by potassium in anesthetized dogs

Either atropine, isoprenaline, neostigmine or practolol was given intravenously in therapeutic doses to dogs anesthetized with pentobarbitone sodium. Cardiac arrhythmias were induced by potassium chloride intravenously as a bolus injection in a dose of 0.3 mmol/kg. The standard electrocardiographic lead II was recorded continuously. pH, Po2 and Pco2 were checked from arterial blood samples before and after the injection. The isoprenaline treated dogs showed the smallest amount of arrhythmias and all the dogs survived. More severe arrhythmias were seen in the neostigmine and practolol treated dogs and the most severe occurrences were encountered in the atropine treated dogs.     

COMPUTED TOMOGRAPHY OF ASPIRATION PNEUMONIA IN A DOG

A dog with aspiration pneumonia was examined by computed tomography (CT) with 8-mm continuous scans of the chest. The results demonstrated that CT is a useful procedure for evaluating pneumonia, although high cost prevents its routine use. A normal littermate was examined, and normal structures of the chest and chest wall were compared.     

Osteochondrotic changes in the vertebrae of four ataxic horses suffering from cervical vertebral malformation

Ataxia caused by a focal compression of the cervical spinal cord was diagnosed in four young standardbred trotting horses. Diagnosis was verified by myelography. Changes in the cervical vertebral column were studied using microradiographic and histologic methods. In the vertebrae involved, there was irregularity of the cartilaginous growth zone, cracks with a loose fragment and disturbance in the enchondral ossification. These changes resemble osteochondrosis. Porous appearance in lateral and ventral funiculi as well as mural calcified plaques in the small vessels of the white matter were found in the spinal cord.     

Autosomal trisomy in a heifer

A malformed Ayrshire heifer had one additional autosome in all the lymphocyte metaphases studied. Chromosome banding techniques showed the karyotype of the calf to be 2n = 61, XX, +24.Slight prognathia of the lower jaw and peculiar abbrevations in the structure of the genitals were the most apparent anomalies, in addition to heart abnormalities, a poorly-closed urachus and slow growth rate.     

Venous drainage of the femoral neck in Legg Perthes disease and in hip dysplasia. A clinical and experimental study in the dog and pig

Three clinical cases of canine avascular femoral head necrosis and 4 cases of hip dysplasia were examined using intraosseus femoral neck venography. The contrast medium passed initio the diaphyseal bone marrow in all cases. Three growing dogs and 7 growing pigs were examined with the same method, before and after experimental ligation of the femoral veins. Before the venous tamponade, no contrast medium was visible in the femoral neck. The venography performed immediately after ligation showed contrast flow into the femoral neck similar to that seen in the clinical cases of Legg Perthes disease or hip dysplasia. However, a collateral circulation developed within 7 weeks. No more contrast-flow into the diaphysis was observed after that time.Although osteomedullography shows that both in Perthes disease and in hip dysplasia venous drainage has failed, venous tamponade may not induce the onset of the disease.Key words: hip dysplasia, Legg Perthes disease, osteomedullography     

Evaluating the accuracy of canine pregnancy diagnosis and litter size using real-time ultrasound

A total of 135 bitches suspected of being pregnant were examined with a real-time ultrasound equipment. 58 bitches were not pregnant. In pregnancy diagnosis ultrasound produced an overall accuracy of 99.3%, sensitivity 98.7%, and specificity 100.0%. Estimation of the litter size was fairly reliable in small litters of 1–3 puppies.     

Vascular abnormalities and deregulation of VEGF in Lkb1-deficient mice

The LKB1 tumor suppressor gene, mutated in Peutz-Jeghers syndrome, encodes a serine/threonine kinase of unknown function. Here we show that mice with a targeted disruption of Lkb1 die at midgestation, with the embryos showing neural tube defects, mesenchymal cell death, and vascular abnormalities. Extraembryonic development was also severely affected; the mutant placentas exhibited defective labyrinth layer development and the fetal vessels failed to invade the placenta. These phenotypes were associated with tissue-specific deregulation of vascular endothelial growth factor (VEGF) expression, including a marked increase in the amount of VEGF messenger RNA. Moreover, VEGF production in cultured Lkb1(-/-) fibroblasts was elevated in both normoxic and hypoxic conditions. These findings place Lkb1 in the VEGF signaling pathway and suggest that the vascular defects accompanying Lkb1 loss are mediated at least in part by VEGF.