Long-term EKG in dogs: comparison between a computerized system and visual arrhythmia analysis]

Based on results of holter ecg recordings taken from 38 dogs the computerized analyses system turned out as method not exactly valuing the frequency and sensitivity of arrhythmias. Despite there was a significant correlation between the computerized and visual arrhythmia analysis for ventricular respectively supraventricular premature beats, in individual cases there was an important aberration between the particular values.     

Teratological examination of the insecticide methylparathion (Wofatox 50 EC) on pheasant embryos. 1. Morphological study

Teratogenic effects of methylparathion / Wofatox 50 EC/ and Parathion 20 WP as positive control material were tested in pheasant embryos. On the 12th day of incubation 0.1 ml of the emulsions or suspensions of the insecticides at different concentrations was inoculated into the air space of embryonated eggs. The following dose levels were employed: 27 and 270 mg/kg egg of Wofatox 50 EC, and 10 mg/kg of Parathion 20 WP. Morphological changes were evaluated by macroscopic, skeletal staining and light microscopic examinations of the embryos. Primary hypoplasia or atrophy developed in the cervical musculature /m. longus colli/ accompanied by lordosis and scoliosis of the cervical spine. In most cases we also found cyllosis .     

Feline one-way mixed leukocyte reaction

The feline one-way mixed leukocyte reaction (MLR) was accomplished by a microtechnique assay using gradient purified mononuclear leukocytes from the peripheral blood of specific-pathogen-free (SPF) cats. An eight day assay was required with an appropriate serum supplement of rabbit or cat serum and obtainable cell concentrations of 1×10⁵ mononuclear cells per well of each responder and stimulator population. This assay was devised as an $\text{in vitro}$ correlate of cell-mediated immunity and to demonstrate that feline histocompatibility differences can be detected in culture.     

Computed tomographic morphology of the synovial invaginations of the distal sesamoid bone of the horse

The morphological features of the distal border synovial invaginations (SI) of the distal sesamoid bone (DSB) in horses were described by the use of computed tomography (CT). Transverse CT images were obtained on 50 cadaver forefeet from 25 Warmblood horses. Dorsal and sagittal planes were reformatted. The CT images allowed the evaluation of the number, shape, depth of penetration and direction of the SI into the bone. The total number of SI was 295 (mean 5.9). The number of invaginations in a particular DSB ranged from 3 (n = 3), 4 (n = 6), 5 (n = 11), 6 (n = 12), 7 (n = 13), 8 (n = 3), 9 (n = 1) to 11 (n = 1). The shape of the SI was 'conical' (n = 118), 'linear' (n = 109), 'lollipop' (n = 38) or 'branched' (n = 30). Penetration of the SI into the DSB was 'mild' in 195 cases, 'moderate' in 67 cases and 'deep' in 33 cases. The SI ran in a 'straight', 'dorsoproximal' and 'palmaroproximal' direction in 187, 28 and 80 cases, respectively. In only six DSBs, all SI ran in the same direction. The images obtained in this study may serve as reference for the radiographic evaluation of these SI.     

Aglepristone decreases proliferation in progesterone receptor-positive canine mammary carcinomas

Background: Progesterone receptor (PR) antagonist aglepristone (RU534) has been used successfully for pregnancy termination and therapy of pyometra, vaginal tumors, and mammary hyperplasia in bitches and queens. All of these conditions share with canine mammary carcinomas the expression of PR. Objectives: To study the effect of RU534 on proliferation and apoptosis in canine mammary carcinomas in relation to PR expression. Animals: Twenty‐seven nonspayed bitches with mammary carcinomas were treated with either 2 doses of 20 mg/kg RU534 (n = 22, RU534‐treated group) or oil placebo (n = 5, control group) on days 1 and 8. Methods: Tumor samples were collected before (day 1) and after (day 15) treatment for immunohistochemistry. PR expression, proliferation index (PI), and apoptotic index (AI) were determined using antibodies against PR, Ki67, and cleaved lamin A/C antigens, respectively. The effect of treatment on these parameters was analyzed. Results: Differential expression of PR between day 1 (59.1% PR‐positive tumors) and day 15 (36.4% PR‐positive tumors) was observed in RU534‐treated tumors exclusively. After RU534 treatment, mean PI was significantly decreased in PR‐positive but unchanged in PR‐negative RU534‐treated tumors. A reduction of ≥20% in PI was found in 61.5% of RU534‐treated tumors with PR expression. Conversely, no effect on AI was observed after RU534 treatment. Conclusions and Clinical Importance: Neoadjuvant RU534 treatment had PR expression‐related inhibiting effects on proliferation of canine mammary carcinoma cells.     

Effect of topical phenylephrine on the equine pupil

The mydriatic effect of 10% phenylephrine was evaluated in 9 horses. Base-line pupillary size in mesopic conditions and during light stimulation was ascertained before application of pharmacologic agents. In study 1, 10% phenylephrine was applied to each eye (n = 5 horses). After 15 minutes, the pupillary size was determined in both lighting conditions. Phenylephrine was again applied to each eye, and after an additional 15 minutes, the pupillary size was determined. In study 2, 1% tropicamide was applied to each eye (n = 4 horses), and after 30 minutes, the pupillary size was determined in both lighting conditions. Tropicamide and phenylephrine were applied to each eye immediately after determination of pupillary size, and after an additional 30 minutes, the pupillary size was determined. There was no significant change (P greater than 0.9) in pupillary size when phenylephrine was used alone or when phenylephrine was used in an eye that had been dilated with tropicamide.     

The developmental pattern of c-fos expression in the rat thalamus following open-field stress stimulation

The thalamic nuclei with their defined set of input-output connections are the primary channel for information flow to the cerebral cortex. Several data suggest that neurons of that area are involved in the response to various aversive stimulations. However the pattern of activation seems to depend on the stress model as well as the stage of maturation. In the present study we would like to check which nuclei of the thalamus show expression of c-fos in the response to the "open field test", and how this response pattern changes during the maturation process. 30 rats of age ranged from P0 to P120 (P-postnatal day) were studied. The experimental group was exposed to the "open field test" for 10 minutes. After perfusion and fixation, brains were cut and stained for c-fos with immunohistochemical method. Our results showed that during development the pattern of c-fos activity in the thalamic nuclei after stress stimulation undergoes significant changes. Distinct c-fos expression was observed in the paraventricular nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus. These findings suggest that these nuclei may play a direct role in the stress reaction involved in the response to the "open field test".