Showing papers by "University of Veterinary Science published in 1991"

Mapping of glial fibrillary acidic protein‐immunoreactivity in the rat forebrain and mesencephalon by computerized image analysis

Abstract: Computer-assisted image analysis was used to map the regional distribution of glial fibrillary acidic protein-immunoreactive (GFAP-IR) astrocytes in the rat forebrain, and mesencephalon. A complete survey of packing densities of GFAP-IR structures was performed. Computer maps revealed high values in the outer and inner layers of the cortex, some hippocampal and olfactory bulb layers, prepiriform cortex, dorsal part of the caudate-putamen, globus pallidus, lateral septum, reticular thalamic nucleus, lateral habenular nucleus, circumventricular organs, nuclei of the medial hypothalamus, substantia nigra, interpeduncular nucleus, and mamillary body. These correspond to regions of the embryonic pial and ventricular brain surfaces, which undergo developmental alterations including growth and various forms of internalization. From this we conclude that in the adult brain, astrocytes of high GFAP-IR are derivatives of surface-contact glia, whereas those located in areas having developed by the local thickening of the neural tube wall show reduced or no GFAP-IR.

Effects of Volatile Fatty Acids on the Epithelial Cell Proliferation of the Digestive Tract and Its Hormonal Mediation

Abstract: Publisher Summary The stratified, horny lining epithelium of the rumen has important physiological functions—such as absorption, transport, metabolic activity, and protection—that presuppose its integrity and ready adaptation to the internal and external environment. One of the main characteristics of rumen adaptation is the changed rate of mucosal cell division, and studies on the factors influencing mitosis may either directly or indirectly throw light on the underlying mechanism. The gastrointestinal mucosal membranes of ruminants adapt themselves mainly to the diet and to the mode and times of feeding. Certain feed components and their fermentation products have an appreciable influence on cell division. An analysis of the interrelationships between diet changes and rumen adaptation presents a feasible approach to the problem. The regressive and progressive changes of the rumen mucosa occur depending on the amount of easily digestible carbohydrate in the diet.

Effect of storage on measurement of ionized calcium and acid-base variables in equine, bovine, ovine, and canine venous blood.

Abstract: The stability of blood ionized calcium (Ca2+) and acid-base variables in equine, bovine, ovine, and canine venous blood samples (n = 15, in each group) stored at 4 C for 3, 6, 9, 24, or 48 hours was studied. Variables included blood Ca2+ and standard ionized calcium (Ca2+ corrected to pH 7.4) concentrations, pH, blood carbon dioxide and oxygen tensions, base excess, bicarbonate concentration, and total carbon dioxide content. Results indicate that storage of blood samples at 4 C for up to 48 hours, despite appreciable acid-base changes, is associated with less than 1.5% change in equine, bovine, and ovine blood Ca2+ concentrations. Similar changes were observed in canine blood during the first 9 hours' storage. After 24 and 48 hours' storage, clinically relevant decrease (10.5 and 15.5%) in canine blood Ca2+ concentration was measured. Therefore, Ca2+ concentration in equine, bovine, and ovine venous blood samples stored up to 48 hours, and in canine blood samples stored up to 9 hours at 4 C is of diagnostic use.

Correlation of ultrasonographic and patho‐morphological findings in canine hepatic diseases

Abstract: Findings of hepatic ultrasonography were analysed in 22 dogs with liver disease and compared with the results of final morphological diagnoses. Ultrasonographic appearance of the liver demonstrated focal alterations in 11 dogs (50 per cent): multifocal lesions in hepatic neoplasia (six), hepatic cirrhosis (one), generalised mycosis (one) and unifocal lesions in haemangiosarcoma (one), nodular hyperplasia (one) and misdiagnosed intestinal invagination (one), Diffuse ultrasonographic alterations were found in 11 dogs (50 per cent): hyperechoic liver of normal/enlarged size in lymphosarcoma (four) and hepatic lipidosis (two); hyperechoic ‘bright’ but small liver in atrophic cirrhosis (two); hypoechoic to normal intensity liver of normal size in liver dystrophy (two) and hepatic venous distension (one). Gallbladder abnormalities were detected in 14 of 20 dogs (70 per cent). Correct ultrasonographic diagnoses were made in 11 dogs (50 per cent). The best results were achieved by combining the clinicolaboratory and ultrasonographic findings, providing a correct diagnosis in 17 dogs (77-3 per cent).

Two-dimensional echocardiographically guided pericardiocentesis in a horse with traumatic pericarditis.

Abstract: Two-dimensional echocardiographic (2DE) examination was performed on a horse with clinical signs of pericardial effusion. Thickening of the pericardium, excess amount of pericardial fluid, elevation of the cardiac apex, and right ventricular compression, characteristic of cardiac tamponade, could be seen on 2DE recordings. Fibrinous pericarditis was suspected by observation of fibrinous strands in the pericardial fluid and epicardial fibrin deposits. Echocardiographically guided pericardiocentesis was performed, and 4 L of fluid was removed from the pericardial sac. Streptococcus zooepidemicus was isolated from the fluid. Pericardiocentesis was repeated for 3 days, and medication was administered. Despite temporary improvement in cardiac function, the horse's condition deteriorated gradually, and euthanasia was performed on the ninth day of hospitalization. Necropsy revealed chronic serofibrinous pericarditis of traumatic origin, attributable to an intercostal stab wound entering the pericardium and the apical portion of the myocardium.

Physilogically beneficial effects of titanium

Abstract: Titanium is the tenth most common element in the Earth's crust In soils we find it in form of TiO2, some titanates and Ti-silicates Therefore, in most cases Ti is not taken up by plants and therefore, it is not a member of the food chain Water-soluble and pH-stable chelate form, Ti-ascorbate was applied in plant and animal nutrition It was demonstrated on a very large scale that Ti-ascorbate has a very avorable, beneficial role in various physiological processes The results show that Ti should be a member of the family of demonstrated beneficial elements

Changes induced in newborn piglets by the trichothecene toxin T-2.

Abstract: Three pregnant sows, being in the last quarter of gestation, were used in an experiment to study the changes induced in newborn piglets by T-2 toxin. One sow was used as control (C). The other two received 24 mg (sow A) and 6 mg (sow B) T-2 toxin, respectively, mixed in the feed, daily, up to the time of farrowing. The piglets of sow A became ill by 48-72 h after birth, while the litters of sow B and C remained healthy. The clinical symptoms included faintness, diarrhoea, decreased blood glucose level, and collapse followed by death. The milk and urine of sow A and the stomach contents of affected and dead piglets contained T-2 toxin and its metabolites. Pathological changes seen at necropsy included acute enteritis, degeneration of the liver and kidneys, and oedema of the mesentery. The stomach was filled with clotted milk. Histopathological and electron-microscopic findings consisted of reduced glycogen content and pathological simple fatty infiltration of the liver cells, lymphocyte depletion and necrosis in the lymphoid follicles of the intestinal mucosa, atrophy of the thymic cortex, and hyperfunction of the adrenal and thyroid glands compared to the control.

Comparison of surface antigens of some Campylobacter fetus subsp. fetus strains of ovine origin by polyacrylamide gel electrophoresis and immunoblotting.

Abstract: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting were used to identify and to compare the surface antigens of eight C. fetus subsp. fetus strains. Seven strains (one of serogroup A and six of serogroup B) were isolated from aborted ovine fetuses, while one strain (serogroup A) originated from an aborted calf fetus. Saline extracts at 56 degrees C and 100 degrees C were used as antigens. Antisera were produced in rabbits. In saline extracts (56 degrees C) of the strains at least 19 fractions were identified by SDS-PAGE, with molecular masses ranging from approx. 4,800 to 205,000. The major bands appeared at 205,000, 66,000, 31,500, 25,000, 21,000 and 17,500. Despite the fact that the strains were cultured from 4 different sheep flocks and belonged to serogroup A or B, the SDS-PAGE profiles of the strains were very similar. When boiled (100 degrees C) extracts were used, a band migrating at 32,500 in sheep strains and a band at 97,500 in the calf isolate were missing. Most of the bands obtained by SDS-PAGE could be identified also by the immunoblot procedure. A or B type specificity of the ovine isolates was due to an LPS fraction, migrating at approx. 21,000, while the other LPS fractions appearing under this region although reacted with antisera did not influence the type specificity. Using alkaline extracts (pH 12) in SDS-PAGE, LPS fractions gave more pronounced profiles. In two of our C. fetus subsp. fetus isolates, plasmids with a molecular mass of 31,500 were identified.

Abortion of a sow caused by Pasteurella aerogenes.

Abstract: Three strains of the Pasteurella aerogenes complex were isolated as sole pathogens from aborted fetuses of a sow aborted at the 12th week of gestation on a farm of 600 sows. Gross pathology showed no characteristic lesions. The isolates were biochemically identical and resembled P. pneumotropica on the basis of their strong indole and urease positivity but they produced gas, were ornithine decarboxylase negative and fermented mannitol but not trehalose. Only a few differences were apparent in biochemical characteristics between the isolated strains and P. aerogenes. They differed from the type strain of P. aerogenes in ornithine decarboxylase activity, indole production and lactose and mannitol fermentation; however, such strains do occur within this heterogeneous species. At the time of abortion the antibody titre of the aborted sow was 1 in 16 when examined with live bacterial suspension and 1 in 128 if boiled antigen was used. Similar strains could not be isolated from the vaginas of aborted sows or pregnant and newly farrowed sows in the same group. The bacteriological, serological and histological findings support the opinion of other workers on the occasional pathogenic nature of P. aerogenes.

Immune reactions and immunopathologic changes induced in ovine fetuses and lambs by maedi-visna virus.

Abstract: Seventy- to 80-day fetuses of Merino ewes were inoculated intramuscularly in utero and 2-week-old lambs of the same breed intratracheally with 10(6.3) TCID50/0.1 ml of maedi-visna virus strain K1512 isolated in Iceland. While no precipitins appeared in the serum of fetuses, such antibodies were demonstrable in the lambs from postinoculation (PI) day 30. Indirect immunofluorescence (IIF) revealed the presence of antibodies in samples from both fetuses and lambs; the detectability of these antibodies, however, varied even within a given animal during the experiment. The serologic results were inversely proportional to the kinetics of circulating immune complex (cIC) production. By the lymphocyte stimulation test (LST), the blastogenic transformation of lymphocytes as measured by 3H-TdR incorporation was 6-8% and 6-14% in the fetuses and lambs, respectively. By antibody-dependent cell-mediated cytotoxicity (ADCC) test, cytotoxic capacity (10-14%) was only demonstrable in lambs inoculated at 2 weeks of age, in the 2nd month of life. Histologic examination showed that in the lungs of both fetuses and lambs lympho-histiocytic infiltration developed from PI week 4. This was later joined by lymphoid hyperplasia in the peribronchial lymph nodes. T lymphocyte proliferation was dominant in these lesions as shown by a histochemical procedure (alpha-naphthyl-acetate-esterase, ANAE). By immunofluorescence (IF), deposited immune complexes (IC) were demonstrable in various organs (wall of cerebral ventricles, endothelium of blood vessels of the brain stem, cerebellum, lungs, kidneys). These IC may play an important role in the pathogenesis of maedi-visna.

Characterization of a new fimbrial antigen present in Escherichia coli strains isolated from calves.

Abstract: Summary Thirteen Escherichia coli strains isolated from calves with diarrhoea, supposed to carry a common antigen were examined for their hemagglutinating activity and compared by bacterial agglutination, double diffusion in two dimensions and by crossed immunoelectrophoresis (CIE). Two of the strains were examined also in the electron microscope. Most of the strains agglutinated red blood cells of horse, ox, guinea pig and chicken, of which the agglutination of ox erythrocytes was mannose-resistant (MRHA). None of the strains agglutinated human erythrocytes. All strains with MRHA of ox red blood cells, regardless to their O: K: H antigens could be agglutinated in unabsorbed or absorbed antisera produced against cultures C1209 (020: K-: H9) and C1213 (09: K36: H-) when live cells as antigens were used. None of these sera agglutinated reference strains carrying K88, K99, 987P, F41 or FY (Att25) antigen respectively. By the double gel diffusion test and by CIE in extracts (60°C) of the strains a common heat labile antigen, responsible for the MRHA of ox red blood cells was identified. Electron microscopy revealed that this common antigen was represented by thin, long, hair-like fimbriae on cells of E. coli C1213, and that specific homologous antibodies attached to these fimbriae.