Showing papers by "University of Veterinary Science published in 1995"

Development of antioxidant capacity in tissues of the chick embryo

Abstract: The concentrations of vitamin E, vitamin A, selenium, reduced glutathione and the activities of glutathione peroxidase and superoxide dismutase were determined in the yolk, yolk sac membrane, liver and brain of the developing chick embryo. The changes in the concentrations of vitamins E and A in the yolk and liver during development were consistent with the occurrence of a preferential transfer of vitamin A from the yolk to the embryo before day 14 of incubation, whereas the main period of vitamin E transfer occurred later, during the last week of incubation. The concentrations of reduced glutathione in the yolk sac membrane, liver and brain were similar at all developmental stages studied. However, the levels of the other measured antioxidant systems were very much higher in the liver than in the brain. Thus, in the newly hatched chick, the levels of vitamin E, vitamin A, selenium, glutathione peroxidase and superoxide dismutase were, respectively, 58.0-, 174.7-, 3.6-, 4.0- and 4.7- fold higher in the liver than in the brain when expressed on the basis of tissue fresh weight.

Effect of various levels of T-2 toxin in the immune system of growing pigs.

Abstract: Four groups of seven-week-old pigs weighing about 9 kg were fed for three weeks a prestarter that contained 0.5, 1.0, 2.0 or 3.0 mg/kg of highly purified T-2 toxin. The average daily intakes of toxin by the pigs were 0.38, 0.81, 1.24 and 1.43 mg, respectively. The experimental and control pigs were immunised with 5 ml aluminum hydroxide gel-absorbed purified horse globulin on the first and fourth days of the treatment period. Blood samples were withdrawn on days 7, 14 and 21 and used for the determination of the titre of anti-horse globulin antibody, for an in vitro lymphocyte proliferation test, using purified horse globulin, phytohaemagglutinin and concanavalin-A and for determinations of the immune complex, the cytotoxic reaction and the phagocytic activity and phagocytic index of circulating granulocytes. The samples taken on day 21 were also used to determine the erythrocyte count, the mean cell volume of the erythrocytes, the haematocrit, the blood haemoglobin concentration, the leucocyte count and the proportion of T lymphocytes. At the end of the experiment samples were taken from the thymus, spleen and mesenteric lymph nodes for histological examination. The diets that contained 2 and 3 mg T-2 toxin/kg caused a significant decrease in the red blood cell count, the mean corpuscular volume and the haemoglobin concentration. A significant decrease in the leucocyte count and the proportion of T lymphocytes was observed in all the treatment groups. There were also dose-dependent, significant decreases in antibody formation and in the blastogenic transformation of lymphocytes, and mild to moderate reactive processes were observed histologically in the lymphoid organs.

Effect of various levels of T-2 toxin on the clinical status, performance and metabolism of growing pigs.

Abstract: In two sets of experiments eight groups of seven-week-old pigs weighing about 9 kg were fed for three weeks a prestarter that contained 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 10.0 or 15.0 mg/kg of highly purified T-2 toxin. The feed of the two control groups was free from T-2 toxin. Average daily intakes of toxin by the pigs were 0.38, 0.81, 1.24, 1.43, 0.93, 0.81, 0.99 and 2.5 mg, respectively. The weight gains, the feed intakes, the extent of feed refusal, the parameters of energy and protein metabolism and the serum concentrations of calcium, inorganic phosphorus and magnesium were affected to different extents by the different doses of T-2 toxin, but the data indicated that feed consumption was reduced and the activity of aspartate aminotransferase was increased by the smallest amount of T-2 toxin tested.

Intestinal absorption of colostral lymphocytes in newborn lambs and their role in the development of immune status.

Abstract: Two model experiments were conducted to study the intestinal absorption of colostral lymphoid cells and the role of these cells in the development of immune status in newborn lambs. In experiment I, 17 lambs of 14 Merino ewes were used. Suspensions of lymphoid cells separated from the colostrum (cell density: 5 x 10(6)/ml) and blood (3 x 10(6)/ml) were labelled with technetium (Na99mTcO4) of 37 MBq/ml radioactive concentration. In three groups of lambs, 10-ml volumes of the cell suspensions were injected directly into the duodenum after laparotomy, while in a fourth group (group Ia) the same volume was administered to the animals through an oesophageal tube. The labelled cells revealed that colostral cells of the lamb's own dam are absorbed from the gastrointestinal tract and get into the newborn lamb's lymph circulation irrespective of the route of application. In experiment II, involving 40 lambs of 40 ewes, we studied the effect of absorbed colostral lymphocytes on the development of the newborn lamb's immune status. Twenty ewes (group A) each were treated with 3 ml tetanus anatoxin twice, while the remaining animals (group B) were left uninoculated. Lambs of group A (designated A2) were separated from their dams immediately after birth, then were administered, through an oesophageal tube, 10 ml of a suspension of lymphoid cells (cell density: 5 x 10(6)/ml) separated from the maternal colostrum. Subsequently, the lambs were interchanged with lambs of nonimmunized ewes of group B (designated lambs B1), i.e. were mutually put out to nursing. At three days of age, lambs of groups A1, A2, B1 and B2 were inoculated with 3 ml tetanus anatoxin, then blood samples were taken from them 5 times in a period of 27 days for comparative examination of the humoral and cellular immune reactions. The results demonstrate that lymphoid cells from the colostrum of the lambs' own dam become absorbed into the newborn lambs' lymph circulation, remain immunologically active and may transfer, besides immunological memory, also cellular activity.

Orientation of agents of wound myiasis to hosts and artificial stimuli in Hungary

Abstract: . The orientation of adults of the myiasis species Wohlfahrtia magnified and Lucilia sericata to artificial visual stimuli (cloth targets) and olfactory stimuli (‘swormlure-4’, a potent screwworm attractant), was studied in sheep pastures near to Sarbogard in Hungary. Experiments with odour-baited cloth targets, enclosed in electrocuting grids, demonstrated that colour was an important factor influencing catches on targets: a black target caught most flies of both species, with other colours in the following order of effectiveness, blue > white > yellow. Wohlfahrtia magnified did not respond to swormlure-4 in the strong manner that L. sericata did. The sex ratios of W. magnifica caught on targets (67.2% males) and hand-netted from fence posts (68.8% males) were similar and biased towards males, whereas that of L. sericata on targets was strongly biased towards females (15.6% males), indicating a fundamental difference in the response of these two myiasis species towards the swormlure-baited targets. The orientation of these two species towards hosts was also recorded together with that of a third species, Phormia regina. Electric nets placed beside infested sheep caught significantly more flies of all three species than those placed beside uninfested sheep or in the absence of sheep. The sex ratio of W. magnified caught around infested sheep was the reverse of that on targets, with 68.5% females. Wohlfahrtia magnifica responded more strongly to healthy, uninfested sheep than did L. sericata and P. regina. The potential for use of targets both for population monitoring and control is discussed.

Age-dependent resistance to Cryptosporidium baileyi infection in chickens.

Abstract: The age-dependent aspects of resistance to Cryptosporidium baileyi were studied in chickens orally inoculated with C. baileyi oocysts at 1 and 9 wk of age. The prepatent period was significantly shorter and the patency was significantly longer in younger birds. Chickens infected at 1 wk of age excreted 3 times the number of oocysts excreted by those inoculated at 9 wk of age. There was a good correlation between the length of the patent period and the total oocyst output of chickens. These results indicate that both innate and acquired resistance to C. baileyi are age-related. The numbers of animals needed per experimental group to estimate the length of the prepatent period, the patency, and the total oocyst output were assessed. Relatively small numbers of animals are required for the estimation of the mean length of the prepatent period, in contrast with the large numbers of birds needed for the estimation of the mean length of the patent period or that of the total oocyst excretion.

Lesions of the renal pelvis and proximal ureter in various nephro-urological conditions: an ultrasonographic study

Abstract: The applicability of ultrasonography was studied in the diagnosis of lesions of the renal pelvis and ureter in 10 dogs. Ultrasonographic findings of processes associated with dilatation and concretion formation in the renal pelvis were described and the differential diagnosis of the lesions was discussed. The authors propose a new classification system for judging processes characterized by dilatation of the renal pelvis. Experience suggests that ultrasonography is an effective procedure in the diagnosis of certain diseases of the upper urinary tract in dogs.

Quantitative method to assess Cryptosporidium oocyst shedding in the chicken model

Abstract: An unsophisticated and fairly sensitive quantitative method and its grounds are described, which proved useful to assessCryptosporidium oocyst shedding in the chicken model. The method is based on the rather slow sedimentation of oocysts. A threshold of sensitivity ranging between 5,000 and 10,000 oocysts/g feces was established for this technique. There was good agreement between triplicate assays over a wide range of oocyst concentrations.

Complex study of the physiological role of cadmium. II. Effect of cadmium load on the cadmium content of eggs.

Abstract: The possibility of "cadmium (Cd) contamination" of eggs and the dynamics of Cd accumulation were studied. A total of 40 (4 x 10) Japanese quails weighing 155-200 g, being at the middle phase of egg production and kept on batteries in a climatized animal house were used. The birds were fed a standard quail layer diet and drank tap-water ad libitum. With the exception of the control group (Cd-0), the diet of the other three groups was supplemented with Cd sulphate homogeneously mixed in the diet so that it contained 75 mg (Cd-75), 150 mg (Cd-150) and 300 mg (Cd-300) per kg. During the 37-day feeding trial the quails' behaviour, health status and daily egg production were monitored and the birds were weighed weekly. The egg production of the experimental groups, particularly of those exposed to a high Cd load, rapidly decreased: at the highest Cd load (300 ppm) egg production completely ceased at days 10-11 of the trial. The total Cd content of the eggs rose already from the 3rd day of the feeding trial and by day 10 it reached a value of 0.777 mg/kg dry matter in the eggs of quails of group Cd-75. This was about five times the value measured in the control quails' eggs (0.165 mg/kg dry matter). The Cd content of the egg-white and egg-yolk (maximum values: 0.212 and 0.107 mg/kg dry matter) also increased to about 2 or 3 times that measured in the control eggs. The Cd content of eggs reached the peak in the 2nd week of the feeding trial, then started to decrease, and in the 3rd and 4th weeks not even the eggs laid by quails exposed to a high Cd load contained more Cd than about twice the concentration measured in the controls' eggs. The elucidation of this hitherto not studied process requires further investigations. The phenomenon may be due to a lack of the protein necessary for Cd transport and to the impairment of Cd absorption and of the excretory activity of the oviduct. The higher Cd concentrations measured in the egg were accompanied by markedly elevated Fe, K and S values. In the egg samples collected in the 4th week a substantial reduction in Ca and P concentration was observed. As regards the mineral elements measured in the egg-shell, a significant negative correlation was established between the concentration of Cd and those of Zn, Mg and Ca.(ABSTRACT TRUNCATED AT 400 WORDS)

Complex study of the physiological role of cadmium. III. Cadmium loading trials on broiler chickens.

Abstract: Cadmium (Cd) loading trials were conducted on a total of 110 (3 x 10 and 4 x 20) broiler chickens prereared for 21 days. The control chickens received no cadmium, while chickens in the six treatment groups were given different doses of Cd as an aqueous solution of CdSO4 administered either into the crop or mixed in the feed. The chickens were kept in a climatized animal house and treated usually for 3-5 weeks (maximum 68 days), with the exception of group Cd-75 chickens which were treated up to 239 days of age. The chickens' health status, body mass and feed consumption were monitored throughout the trial. On days 14-20 and on day 42 of the trial 2 chickens per group, then at the end of trial a total of 25 chickens were killed in anaesthesia. These birds, together with chickens that died or were killed during the trial, were subjected to detailed gross pathological examination. From 11 organs (kidney, liver, spleen, testicle, brain, myocardium, skeletal muscle, lungs, digestive tract, pancreas, tubular bones) of these chickens samples were taken for assay for a total of 16 elements, as well as for light and electron microscopic examination. With the exception of groups Cd-30 and Cd-600, no abnormal clinical signs were observed in the first two weeks of the trial. Chickens of group Cd-30 died before day 8-12 of the trial among signs of complete anorexia, rapid emaciation, huddling and diarrhoea, while chickens of group Cd-600 died before day 28, showing similar clinical signs. The body mass of chickens fed a Cd-supplemented diet either remained constant or decreased substantially, in a degree proportional to the Cd load. The only exception was group Cd-2.5, in which the average body mass of birds at the end of week 8 slightly exceeded that of the controls. Four out of the 10 cockerel chicks fed a diet containing 75 ppm Cd up to 239 days of age died of intercurrent diseases; the remaining six grew well and reached a body mass of 3.8-4.3 kg. Feed conversion efficiency was satisfactory in the control group and in group Cd-2.5 (2.1 and 2.4 kg, respectively) and could not be evaluated in a realistic manner in the other groups. At necropsy, the cockerel chicks of groups Cd-30 and Cd-600 showed severe emaciation, liver and kidney degeneration, myocardial hypertrophy and cardiac dilatation.(ABSTRACT TRUNCATED AT 400 WORDS)

Potentiation of ionophorous anticoccidials with duokvin: battery trials against Cryptosporidium baileyi in chickens.

Abstract: Three battery tests, employing 444 Arbor Acres chickens, were conducted to study the anticryptosporidial efficacy of the polyether ionophorous anticoccidials alone and in combination with a new dihydroquinoline antioxidant, duokvin. The following efficacy percentages for the ionophores at the recommended level were established on the basis of oocyst output: lasalocid 45, monensin 37, semduramicin 29, narasin 23, and maduramicin and salinomycin 21. The efficacy of the ionophores, with the exception of lasalocid, could be increased to 36-88% by combination with duokvin. However, these combinations resulted in a significant weight gain reduction due to toxic interaction. Efficacy showed a strong negative correlation with body weight gain and bursa weight, suggesting an indirect mode of action against the parasite. It has been concluded that neither ionophorous anticoccidials nor their combinations with duokvin can be recommended for chemoprophylaxis against avian cryptosporidiosis.

Poor semen quality in Irish wolfhounds: A clinical, hormonal and spermatological study

Abstract: On the basis of clinical observations, Irish wolfhounds were suspected as being subject to a relatively high incidence of soft testicular consistency and low semen quality. Thirty-seven Irish wolfhounds and 67 dogs of other breeds (control group) were therefore examined. Conventional andrological studies were performed in both groups, these included libido testing, palpation and measurement of testes and semen evaluation. Semen evaluation was performed both manually and by videomicrographic analysis. Testosterone concentrations were measured both before and after human chorionic gonadotropin challenge in the Irish wolfhounds. The Irish wolfhounds had lower libidos than the control group. More Irish wolfhounds (21.2 per cent) exhibited low semen quality than the control group (6.1 per cent). Soft testicular consistency occurred more frequently in Irish wolfhounds (25.7 per cent) than in the control group (10.5 per cent). In the control group, bodyweight correlated significantly with total sperm count. Serum testosterone concentration did not correlate with semen quality parameters.

Evaluation of blood lipid peroxidation parameters in carbon tetrachloride (CCl4) toxicity in sheep.

Abstract: Seven female, 2-year-old, nonpregnant, Merino ewes were treated with a nonlethal dose of 0.3 ml/kg body mass carbon tetrachloride (CCl4) in 1:1 v/v dilution with paraffin oil via a stomach tube into the rumen. Blood samples were collected one day before and on the first, second, third, seventh and tenth day after toxin exposure to study the changes of the lipid peroxidation (LP) status of red blood cell haemolyzate (RBC-haem). The severity of liver damage was monitored by determination of aspartate aminotransferase (AST) activity and bilirubin concentration in the blood plasma. Twenty-four h after CCl4 exposure all animals became lethargic and anorexic, their heart rate and respiratory rate increased. On the subsequent two days these signs became more severe, but by the 10th day the symptoms disappeared. On the 1st and 2nd day following CCl4 exposure the concentration of malondialdehyde (MDA)--an end product of LP--in RBC-haem significantly increased. A slight decrease was found on the 3rd, 7th and 10th day, but MDA values remained significantly higher than the basal ones. The activity of glutathione peroxidase (GPX) in RBC-haem increased slowly on the 1st and 2nd day, then it rose intensively on the third day. GPX activity remained elevated until the 7th day, but on the 10th day it dropped again. Catalase (Cat) activity in RBC-haem did not show any significant changes during the experiment. AST activity in blood plasma showed a two-fold increase in the first three days; later on the high values decreased. Total and direct plasma bilirubin concentration slightly increased on the 3rd day, then both decreased. LP effects in CCl4-induced hepatocellular injury were significant in sheep, in line with the results of experiments on other species such as rats. The LP effects were demonstrated by the elevated MDA concentration and GPX activity.

Isolation of Bacteroides ureolyticus from vaginal discharge of mares.

Abstract: Summary A total of seven Bacteroides ureolyticus strains were isolated from the cervix and the clitoral fossa of mares with vaginal discharge. No other bacteria capable of causing metritis or vaginitis were isolated from the samples. The isolated strains resembled Taylorella equigenitalis. Both species are catalase, oxidase and alkaline phosphatase positive, but, in addition to these characteristics, B. ureolyticus strains produced urease and they could not tolerate 10% O2. They also failed to be agglutinated in a hyperimmune serum raised against T. equigenitalis; however, B. ureolyticus and T. equigenitalis were agglutinated in the slide agglutination test in a serum produced against one of the B. ureolyticus isolates. Further investigations are needed to clarify the pathologic role of B. ureolyticus in genital infections of mares and other animals.

The remote astroglial response (RAR): a holistic approach for evaluating the effects of lesions of the central nervous system.

Abstract: The right dorsal lateral geniculate nucleus was stereotaxically destroyed in adult albino rats. After 3 to 150 days of survival the visual cortices from both hemispheres were processed for semithin histology, electron microscopy, GFAP immunohistochemistry and immunoblotting. In visual cortices with histologically disclosed degeneration of the geniculo-cortical tract, a hypertrophy of astrocytes without change in their total numbers was seen from postoperative day 3. From day 7, a rise in GFAP immunoreactivity was observed, reaching its peak between days 11–14, after which a decrease occurred. Observations were confirmed by computer-assisted image analysis of immunohistochemical preparation. Using the immunoblot technique, relative GFAP levels were found to change in a fashion similar to immunohistochemical findings. This showed that synaptic degeneration triggered an up-regulation of GFAP synthesis in the perisynaptic astrocyte processes as a second, cytoskeletal phase of the astrocyte reaction. The phenomenon is denoted as the remote astroglial response (RAR) and is though to be a marker of synapase removal during plastic changes either related to function or induced by lesions. An extrapolation is made to the possible significance of whole-brain GFAP levels in assessing the effects of focal CNS lesions.

Effect of methionine and its related compounds on rumen bacterial activity

Abstract: The effect of several methionine sources (L‐methionine = L‐MET; DL‐ methionine = DL‐MET, DL‐S‐methyl‐methionine‐sulphonium‐chloride = SMM; N‐hydroxymethyl‐DL‐methionine‐Ca = NHM; methionine‐hydroxy‐analog free acid=MHA; methionine‐sulphoxyde=MSO) on rumen bacterial growth was studied using a new methodical approach which utilises a methionine free assay medium (Bacto Methionine Assay Media, Difco) supplemented by increasing quantities of the methionine sources and inoculated with one drop of diluted rumen bacteria. The optical density was measured after 18 h incubation on 39 °C. L‐ and DL‐MET promoted the highest growth response, while SMM and NHM exerted significantly (p < 0.05) lower optical densities. MHA and MSO showed no growth response. The methodical approach and the possible bacterial strains, which might have contributed to the growth response have been discussed.

Areas of dormant glial fibrillary acidic protein (GFAP) immunoreactivity in the rat brain as revealed by automated image analysis of serial coronal sections.

Abstract: Coronal vibratome sections of the rat brain were immunostained for glial fibrillary acidic protein (GFAP) a major cytoskeletal protein typical for astrocytes. Using computer-assisted image analysis of whole sections, a substantial heterogeneity in regional staining intensities was pointed out. The middle layers of the neocortex, the thalamus and caudate-putamen and the tectal and tegmental part of the mesencephalon were found to show no detectable staining, while peak staining intensities were measured for the pallidum, septal triangular nucleus, hippocampus, medial geniculate nucleus and interpeduncular nucleus. In some of the negative areas neural lesioning induced the appearance of GFAP immunoreaction parallel to an up-regulation of GFAP synthesis. On this basis it was assumed that GFAP immunoreactivity is dormant in these astrocytes and plastic changes in the neuropil trigger its expression.

Toxicological studies on potentiated ionophores in chickens. II. Compatibility study.

Abstract: Two trials were carried out on a total of 2 x 360 Tetra-82 broiler chickens to study how the presence of the antioxidant duokvin as potentiating agent influenced the compatibility of reduced doses of monensin (12.5 mg/kg of feed) or maduramicin (3.0 mg/kg of feed) with other chemotherapeutic agents (tiamulin, erythromycin, sulfaquinoxaline, sulfachlorpyrazine, flumequine, tylosin, kitasamycin) widely used in broiler rearing. Compatibility was assessed on the basis of the appearance of clinical signs suggestive of toxic interaction, the mortality rate, body mass gain, feed consumption and drinking water intake, and changes in AST and LDH activities of the blood plasma. The monensin-duokvin combination (12.5 mg monensin/kg of feed + 120 mg duokvin/kg of feed) was found to be compatible with erythromycin, sulfaquinoxaline, sulfachlorpyrazine, flumequine, tylosin and kitasamycin. For tiamulin, a slight incompatibility was observed; however, this was much less severe than that found for monensin administered at a dose of 100 mg/kg of feed. The maduramicin-duokvin combination (3.0 mg maduramicin/kg of feed + 120 mg duokvin/kg of feed) was compatible with all the compounds tested; thus, it can be safely applied also in combination with tiamulin.

Oral bioavailability of sulphonamides in ruminants: a comparison between sulphamethoxazole, sulphatroxazole, and sulphamerazine, using the dwarf goat as animal model.

Abstract: The various sulphonamides show marked differences in disposition characteristics after administration to ruminants. For use in combination with a diaminopyrimidine derivative such as trimethoprim or baquiloprim, it is essential that a sulphonamide has similar pharmacokinetic properties in order to obtain optimal synergy. In the present study the pharmacokinetics of sulphamethoxazole, sulphatroxazole, and sulphamerazine were investigated in dwarf goats (n = 6) after IV and intraruminal administration at a dose of 30 mg/kg bodyweight. In addition, the in vitro binding of sulphamerazine to ruminal contents was studied as a possible explanation for a reduced absorption rate. Sulphamethoxazole showed the most rapid absorption after intraruminal administration (mean tmax +/- SD : 0.8 +/- 0.2h). However, the drug was rapidly eliminated from the plasma (t1/2 beta : 2.4 +/- 1.5 h) and the bioavailability was only 12.4 +/- 4.7%, most likely due to an extensive 'first-pass' effect. The bioavailability of orally administered sulphamerazine and sulphatroxazole was much higher (67.6 +/- 13.5% and 70.2 +/- 32.3%, respectively). After intraruminal administration, sulphatroxazole showed the highest plasma peak concentration (26.1 +/- 6.3 mg/l) and the longest plasma half-life (4.7 +/- 1.8h) and mean residence time (13.9 +/- 4.5 h). Sulphamerazine showed considerable binding to rumen contents in vitro. Based on its pharmacokinetic properties sulphatroxazole appears to be a suitable candidate to be used in combination with the more recently developed diaminopyrimidines such as baquiloprim.

Toxicological studies on potentiated ionophores in chickens. I. Tolerance study.

Abstract: The tolerance of chickens to monensin (12.5 mg/kg of feed) and maduramicin (3.0 mg/kg of feed) fed at a reduced dose in the presence of the antioxidant duokvin was studied in two experiments including 2 x 200 Tetra-82 broiler chickens. Tolerance was assessed by the appearance of clinical signs indicative of a toxic effect, the number of deaths, the groups' body weight gain, feed and drinking water intake, the aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities, calcium ion, inorganic phosphate and total protein content of the blood plasma, the haematocrit value, and haemoglobin concentration. When applied at a dose that had proved to be optimum in the efficacy studies, neither the monensin-duokvin combination (12.5 mg monensin per kg of feed + 120 mg duokvin per kg of feed) nor the maduramicin-duokvin combination (3.0 mg maduramicin per kg of feed + 120 mg duokvin per kg of feed) exerted a statistically significant influence on the parameters tested.

Species-specificity of glial vimentin as revealed by immunocytochemical studies with the Vim 3B4 and V9 monoclonal antibodies.

Abstract: Two monoclonal antibodies directed against vimentin, Vim 3B4 and V9 could distinguish between vimentins originating from certain species, when tested on cell lines (Bohn et al, 1992) Our comparative immunohistochemical studies in the rat and chicken brain with the same antibodies suggest the coexistence of two vimentin forms in the glial cells of both species One of these forms bearing the epitope present in the respective non-glial cell lines is present in astrocytes and Bergmann glia independently of the ontogenic state of the animal The other epitope appeared also mutually in both species, albeit its expression was more restricted These patterns suggest that in these two species, the expression of the different vimentin forms might be differently regulated

Toxicological studies on potentiated ionophores in chickens. III. Electrotoxicological investigations.

Abstract: The effect exerted by the simultaneous administration of tiamulin (40 mg/kg body mass) and a lowered dose (12 mg/kg of feed) of monensin combined with the antioxidant duokvin on the conductivity of peripheral nerve and the electrophysiological function of the heart was studied in two trials comprising 3 x 6 broiler chickens. For the study of peripheral nerve function, chickens were anaesthetized with pentobarbital sodium, the sciatic nerve (n. ischiadicus) was exposed in the sciatic arc, and bipolar stimulating and efferent electrodes were inserted directly beside the nerve, at an average distance of 20 mm from each other. For the recordings, the nerve was stimulated with 16 supramaximal impulses of 0.02 ms duration, applied at 15-s intervals. The responses given to the stimulus were recorded with the help of a polygraph and evaluated with a computer in online mode. For the study of cardiac function, the chickens were anaesthetized with methomidate. The electrocardiograms were taken in Einthoven's lead II with the help of needle electrodes, and then evaluated with computer in online mode. In control chickens, maximum conduction velocity was 30.70 +/- 0.52 m/s on the average. That value did not change after a single treatment with monensin-duokvin + tiamulin, while it underwent a slight but statistically significant decrease after two treatments. Studies on the electrical function of the heart revealed no signs of dysfunction in either of the treated groups as compared to the control.(ABSTRACT TRUNCATED AT 250 WORDS)