Showing papers by "University of Veterinary Science published in 1998"
TL;DR: R‐LM interneurons comprise several distinct populations which evoke fast GABAA receptor‐mediated IPSPs, and the domain‐specific innervation of postsynaptic pyramidal cells suggests functionally diverse effects on the integration of afferent information in functionally non‐equivalent compartments of pyramid cells.
Abstract: 1. Hippocampal non-principal neurons at the stratum radiatum-stratum lacunosum-moleculare border (R-LM interneurons) of the CA1 area may constitute several cell classes and have been implicated in the generation of GABAergic unitary IPSPs. Using biocytin-filled electrodes we recorded R-LM interneurons intracellularly in vitro and determined their postsynaptic effects in concomitantly recorded pyramidal cells. 2. Light microscopic analysis revealed four populations of R-LM interneurons with distinct axons: (1) basket cells (n = 4) with axons predominantly ramifying in the pyramidal cell layer; (2) Schaffer collateral/commissural pathway-associated interneurons (n = 10) stratifying in stratum radiatum and, to a lesser extent, stratum oriens; (3) perforant pathway-associated interneurons (n = 6) innervating the perforant path termination zone in stratum lacunosum-moleculare of the CA1 area as well as equivalent portions of the dentate gyrus and subiculum; and (4) neurogliaform interneurons (n = 2) characterized by their dense, compact axonal and dendritic arbour. 3. Random electron microscopic sampling of synaptic targets revealed a preponderance of pyramidal neurons as postsynaptic elements. Basket cells had a synaptic target preference for somata and proximal dendrites, whereas the remainder of R-LM interneurons innervated dendritic shafts and spines. The axon of dendrite-targeting cells formed up to six putative contacts with individual postsynatpic pyramidal cells. 4. Anatomically recovered R-LM interneurons (n = 22) had a mean resting membrane potential of -56.7 +/- 3.6 mV, a membrane time constant of 12.9 +/- 7.7 ms and an input resistance of 86.4 +/- 29.2 M omega. Depolarizing current pulses generally elicited overshooting action potentials (70.8 +/- 6.9 mV) which had a mean duration, when measured at half-amplitude, of 0.7 +/- 0.1 ms. In response to prolonged (> 200 ms) depolarizing current pulses all R-LM interneurons displayed (a varying degree of) spike frequency adaptation. 5. Basket cells, Schaffer-associated and neurogliaform interneurons elicited small-amplitude (< 2 mV), short-latency IPSPs in postsynaptic pyramids (n = 5, 13 and 1, respectively). Those interactions in which an effect was elicited with the repetitive activation of the presynaptic neuron (n = 13) showed a substantial degree of postsynaptic response summation. Unitary IPSPs had fast kinetics and, whenever tested (n = 5; 1 basket cell and 4 Schaffer-associated interneurons), were abolished by the GABAA receptor antagonist bicuculline. 6. Thus, R-LM interneurons comprise several distinct populations which evoke fast GABAA receptor mediated IPSPs. The domain-specific innervation of postsynaptic pyramidal cells suggests functionally diverse effects on the integration of afferent information in functionally non-equivalent compartments of pyramidal cells.
200 citations
TL;DR: The accuracy of detecting nonpregnant animals by both protein tests was limited by the relatively long half-life of these proteins after calving and by early embryonic mortality.
142 citations
TL;DR: The forebrain/innovation trend is independent of juvenile development mode, but phylogeny appears to be an important intervening variable in Australasia, as evidenced by non-significant independent contrasts.
Abstract: Many authors have proposed that behavioural flexibility in the field is associated with learning ability in captivity, relative forebrain size and rate of structural evolution. In birds, the frequency of feeding innovations reported in the short notes sections of ornithology journals may be a good way to operationalize flexibility. In this paper, we examine in the birds of Australia and New Zealand the relationship between forebrain size and innovation frequency found in a previous study covering North America and the British Isles. From a methodological point of view, the two variables are highly reliable: innovation frequency per taxonomic group is similar when different readers judge innovation reports and when different editorial styles govern journals; relative forebrain size yields very similar estimates whether mean residuals from a log-log regression are used or ratios of forebrain to brainstem mass. Innovation frequency per taxon is correlated between the two Australasian zones and between these zones and the more northerly ones studied previously. Innovation frequency is also associated with relative forebrain size in Australia and, to a lesser extent, in New-Zealand; in Australia, parrots show the high frequency of innovations predicted by their large forebrain, but yield no innovations in the New Zealand sample. The forebrain/innovation trend is independent of juvenile development mode, but phylogeny appears to be an important intervening variable in Australasia, as evidenced by non-significant independent contrasts.
111 citations
TL;DR: Results showed that before day 31, ultrasonographic scanning was not very sensitive because six of the 30 calving cows were incorrectly diagnosed as non-pregnant, and plasma levels of bPAG-1 and progesterone proved that four of the cows which had early positive Ultrasonographic diagnoses but did not produce a calf, were pregnant when they were examined.
Abstract: Between days 27 and 59 after artificial insemination (AI), 189 ultrasonographic pregnancy diagnoses were made in 56 dairy cows using a 7.5 MHz linear-array rectal transducer. Blood samples were withdrawn from a jugular vein on the day of Al, on day 21, and after each ultrasonographic examination between days 27 and 31, days 34 and 38, days 41 and 45 and days 55 and 59 after AI. Plasma concentrations of bovine pregnancy- associated glycoprotein 1 (bPAG-1) were measured by radioimmunoassay. The results showed that before day 31, ultrasonographic scanning was not very sensitive because six of the 30 calving cows were incorrectly diagnosed as non-pregnant. In five of these animals, the uterus was located far cranial to the pelvic inlet. Five of the cows examined between days 27 and 31 were pregnant on the basis of plasma bPAG-1 levels on the same day, using 0.5 ng/ml as the cut-off point. Plasma levels of bPAG-1 and progesterone proved that four of the cows which had early positive ultrasonographic diagnoses but did not produce a calf, were pregnant when they were examined.
69 citations
Journal Article•
TL;DR: The evaluation of individual progesterone profiles has revealed that the microplate ELISA detects the time of ovulation at the same time as it is determined by the RIA and clinical examination.
Abstract: Several assay systems (3H radioimmunoassay (RIA) with and without extraction; microplate enzyme-linked immunoassay (ELISA); qualitative ELISA (tube test)] were used to measure plasma progesterone concentration in mare plasma. The direct RIA showed a close correlation (R = 0.94) with the extraction RIA. The direct RIA and the microplate ELISA were compared in two different studies. In the first study 1155 samples of postpartum mares were used for progesterone determination with both assays. The ELISA resulted in more elevated values both in oestrus and dioestrus (0.19+/-0.3 and 2.44+/-3.62 nmol/l for oestrus, n = 436, and 8.94+/-4.29 and 27.88+/-18.34 nmol/l for dioestrus, N = 719, for the RIA and ELISA, respectively, R = 0.71). The evaluation of individual progesterone profiles has revealed that the microplate ELISA detects the time of ovulation at the same time as it is determined by the RIA and clinical examination. The sensitivity and specificity were calculated for different progesterone threshold values. In the second study including 7 non-pregnant, cycling mares the progesterone concentration of 240 samples was determined by both assays. Basal values (Day 0) obtained with the ELISA were higher (1.57 nmol/l) than those of the RIA (0.2 nmol/l). Both curves reached the same maximum concentration (12.11 and 12.45 nmol/l) 5 days after ovulation. The correlation between the RIA and ELISA values was high (R = 0.90). The tube test was compared to the microplate ELISA as reference using 576 plasma samples of 34 non-pregnant, non-cycling mares included in an ovulation induction study. Of these samples 118 had higher and 458 had lower values than 3.18 nmol/l. In most cases the tube test was in complete agreement with the microplate ELISA. The sensitivity, specificity, + predictive and - predictive values for the tube test were 79.7%, 95.4%, 81.7% and 94.8%, respectively.
43 citations
TL;DR: The radiographic method reported in this paper showed be a useful complement to diagnostic methods that have so far been based exclusively on fish dissection, and showed good agreement with dissection findings.
Abstract: The nematode Anguillicola crassus appeared in Europe about 15 yr ago, and has subsequently become recognised as a cause of major pathological lesions in the swimbladder of the European eel Anguilla anguilla. The radiographic method reported in this paper showed be a useful complement to diagnostic methods that have so far been based exclusively on fish dissection. Using this method, the infection of the swimbladder and the severity of its pathological changes can be assessed in a reliable manner without causing damage to the fish. By analysing radiographs of 45 eels from Lake Balaton, 5 stages of swimbladder lesions were distinguished. The method enables the examiner to draw conclusions on the air, worm and exudate content of the swimbladder; however, data on thickening of the swimbladder wall can be obtained only indirectly. The radiograph also provides information on the air and worm content of the pneumatic duct. Results obtained by radiography showed good agreement with dissection findings. Radiographic results are compared with pathological findings obtained from fish dissections separately for each severity grade of infection.
40 citations
TL;DR: Although SC was superior to video imaging for estimating testicular size, ultrasonographic imaging of the testes has considerable potential for the evaluation of testicular function in bulls.
38 citations
TL;DR: It is concluded that under field conditions the resumption of cyclic ovarian activity and sexual behavior in mares after foaling are strongly affected by the season of parturition and parity.
35 citations
34 citations
TL;DR: Both flies were unable to complete their development at higher and lower moisture levels, however both species were from laboratory strains that have been selected for development at optimum moisture levels.
Abstract: Hydrotaea aenescens (Wiedemann) and Musca domestica L. were reared separately and successfully in poultry and pig manure with moisture levels of 50–80%. H. aenescens produced more pupae in poultry manure, but heavier pupae in pig manure. The reverse was true for M. domestica. Both flies were unable to complete their development at higher and lower moisture levels, however both species were from laboratory strains that have been selected for development at optimum moisture levels. Implications for biological control are discussed.
33 citations
TL;DR: Veterinarians in Hungary reported that fly larvae were present deep in wounds rather than superficially, consistent with infestations due to the obligate parasite Wohlfahrtia magnifica (Diptera: Sarcophagidae).
Abstract: Veterinarians in Hungary were asked to complete a questionnaire on traumatic myiasis; of the 664 veterinarians contacted, 247 replied (37.2 per cent) and of these 209 (84.6 per cent) reported myiasis to be a problem among the livestock they treated. Infestation levels of >10 per cent of animals were reported in sheep, cattle and horses. The myiasis season lasted from March to November with most cases reported in July and August. Significantly more respondents reported that fly larvae were present deep in wounds rather than superficially, consistent with infestations due to the obligate parasite Wohlfahrtia magnifica (Diptera: Sarcophagidae). Frequent inspections and the treatment of infested animals were reported by 64.1 per cent of respondents as contributing to the economic impact of traumatic myiasis, and approximately half of the respondents (51.4 per cent) reported that inspections and treatments were carried out at least weekly during the summer. The most common form of treatment was the manual removal of larvae followed by topical application of insecticides, particularly organophosphates. More than half of the respondents (56.6 per cent) reported that there had been no change in the importance of myiasis over the last five to 10 years, but of those who reported a change, more reported an increase (28.3 per cent) than a decrease (15.2 per cent).
TL;DR: In a 10-year-old ovariohysterectomized standard Schnauzer, the finding of dexamethasone-resistant hypersecretion of cortisol, the results of computed tomography, and elevated plasma concentrations of ACTH suggested the presence of both adrenocortical tumour and pituitary-dependent hyperadrenocorticism, which is suggested to be related to the vascular supply of the adrenals.
Abstract: Summary In a 10‐year‐old ovariohysterectomized standard Schnauzer, the finding of dexamethasone‐resistant hypersecretion of cortisol, the results of computed tomography, and elevated plasma concentrations of ACTH suggested the presence of both adrenocortical tumour and pituitary‐dependent hyperadrenocorticism. The dog made an uneventful recovery after bilateral adrenalectomy and remained in good health for 31/2 years with substitution for the induced hypoadrenocorticism. Then the enlarged pituitary caused neurological signs and eventually euthanasia was performed. The surgically excised right adrenal contained a well‐circumscribed tumour of differentiated adrenocortical tissue and in the left adrenal there were two adrenocortical tumours and a pheochromocytoma. The unaffected parts of the adrenal cortices were well developed and without regressive transformation. At necropsy there were no metastatic lesions. The cells of the pituitary tumour were immunopositive for ACTH and had characteristics of malignan...
TL;DR: It is concluded that the optimization of host defense and parasite evasion strategies may select ectoparasites for site segregation and this may stabilize the coexistence of parasite species.
Abstract: Site segregation of coexisting ectoparasite species may result either from a direct interaction such as resource competition between them or from a host-mediated interaction. Here we present an individual-based model for the coevolution of 1 host and 2 parasite species to study this latter hypothesis. Parasite species are generalists at the start of the simulation and develop site specificities under the following assumptions. Parasite populations are not subject to resource limitations but are limited directly by host defense as predation. Hosts have 2 sites that need different defensive abilities to reduce their parasite burden. Parasites need to exhibit different evasive abilities to survive on different sites. Host grooming selects parasites for an increasing capability for evasion, whereas parasites select hosts for an increasing efficiency of grooming. Two trade-offs are incorporated into the model: one between host defensive abilities on the 2 sites, and another between parasite evasive abilities on the 2 sites. We conclude that, under these assumptions, the optimization of host defense and parasite evasion strategies may select ectoparasites for site segregation and this may stabilize the coexistence of parasite species.
TL;DR: The blood-brain barrier is permeable for the anthelmintics tested, and the brain of mice does not provide a site promoting survival of larvae, indicating application of medicated dry food (pellets) may be a simple way of improving efficacy of treatment compared to oral drenching.
Journal Article•
TL;DR: The two main groups of placental proteins of ruminants are discussed in this paper: chorionic somatomammotropins (placental lactogens) and pregnancy-specific (-associated) proteins.
Abstract: The two main groups of placental proteins of ruminants are discussed in this paper: chorionic somatomammotropins (placental lactogens) and pregnancy-specific (-associated) proteins. Placental lactogens belong to the prolactin and growth hormone family. They stimulate mammogenesis, fetal growth and maternal metabolism. Pregnancy-specific proteins and pregnancy-associated glycoproteins belong to the aspartic proteinase family like pepsin, cathepsin D and E. These two groups of proteins are secreted in the maternal circulation by the binucleate cells after their migration to and fusion with the uterine cells. Their profiles were determined by radioimmunoassay (RIA). Further investigations are in progress to relate secretory profiles with alterations of the trophoblastic function such as those occurring in embryonic mortality, abortion, and fetal distress. The endocrine function of the primate and equine placenta is also discussed.
TL;DR: The results presented here suggest that concurrent CAV infection increases the reproductive potential of C. baileyi in chickens, and both pathogens have synergistic effect on each other.
TL;DR: Sticky boards offer a simple technique for trapping both sexes of tabanids, especially males, which are poorly represented in many tabanid traps, and encourages the exploration of a wider range of compounds astabanid repellents than are used at present.
Abstract: Tabanid flies were captured in a sheep pasture in Hungary using black plastic boards (30 × 30 cm), coated with an adhesive sheet, which were either unbaited or baited with ethane-ethiol or Swormlure-4. Five species of tabanid were caught, of which Tabanus tergestinus was caught in the greatest number (87% of 192). The sex ratio of T. tergestinus on unbaited boards was not statistically significantly different to equality. However, on baited boards, males were significantly more numerous, probably due to a repellent effect of the odours on female tabanids. Because of the importance of repellents in tabanid control, this result encourages the exploration of a wider range of compounds as tabanid repellents than are used at present. Sticky boards offer a simple technique for trapping both sexes of tabanids, especially males, which are poorly represented in many tabanid traps.
TL;DR: It is suggested that infection of hens with C. baileyi results in partial protection of their progeny to this parasite, and factors other than immunoglobulins may also be transferred via the eggs.
TL;DR: Concerning repeatability and reproducibility, Z-agar proved to be superior to cetrimide agar, and a relevant and statistically significant difference was found in the results of sample I in favour of theZ-agar, that could indicate the presence of a low number of bacteria.
Journal Article•
TL;DR: The present study suggests that ultrasonography is a valuable tool for diagnosing small intestinal obstruction in the dog.
Abstract: Ultrasonography was performed on 44 dogs to decide whether small bowel obstruction was present. The sonographic criteria for small bowel obstruction were (1) the presence of pendulous movement of the ingesta inside the dilated bowel, (2) observation of invaginated intestines or an ingested intraluminal foreign body, (3) observation of non-uniform peristaltic activity of the dilated intestines, or (4) observation of akinetic intestinal loops together with abdominal fluid accumulation. By using these criteria, obstruction was correctly diagnosed by ultrasonography in 11 of the 13 dogs with mechanical ileus, and obstruction was correctly excluded in 29 of the 31 non-obstructive cases. Thus, the above-mentioned sonographic criteria had 85% sensitivity and positive predictive value, and 94% specificity and negative predictive value. The present study suggests that ultrasonography is a valuable tool for diagnosing small intestinal obstruction in the dog.
Journal Article•
TL;DR: The non-radioactive method performed well in assays in bovine mononuclear cells derived from prolactin-treated or -untreated calves, showing a 50% lower responsiveness to mitogenic stimulation in prolactIn-deprived animals.
Abstract: A rapid colorimetric non-radioactive assay for the determination of bovine mitogen-induced lymphocyte proliferation in cell culture was evaluated using a novel tetrazolium compound (MTS) and an electron coupling reagent (PMS) provided in the CellTiter 96 kit (Promega). The results of the new method were compared with those of the 3H-thymidine incorporation assay using parallels obtained from the same lymphocyte population. The concentrations used in the cell suspension of primary cultured lymphocytes resulted in a significant signal/background ratio when cells were prepared from peripheral blood, spleen or mesenteric lymph nodes. The same concentrations of thymocytes resulted in a weak signal even for the highest concentrations of mitogen. A good correlation was demonstrated between the results of the two methods. The non-radioactive method performed well in assays in bovine mononuclear cells derived from prolactin-treated or -untreated calves, showing a 50% lower responsiveness to mitogenic stimulation in prolactin-deprived animals.
TL;DR: The findings suggest that dystrophin is an integral protein of the postsynaptic component of spine Synapses but is lacking in a subpopulation of hippocampal spine synapses.
Abstract: DYSTROPHIN immunocytochemistry was carried out using monoclonal antibody against the C-terminal part of dystrophin (Dys2) in rat cerebral cortex, cerebellum and hippocampus containing a high number of spine synapses of similar morphological character. Dys2 immunoreactivity was found in the spine component of spine synapses. Particularly heavy label was observed on the postsynaptic densities. In the cerebral and cerebellar cortices all spines were immunopositive. In the hippocampus some postsynaptic densities were intensely immunostained, whereas those of adjacent synapses remained unstained. The findings suggest that dystrophin is an integral protein of the postsynaptic component of spine synapses but is lacking in a subpopulation of hippocampal spine synapses. The heterogeneity of input to the hippocampal spiny sites by contrast to the homogeneous population of fibres synapsing with cerebral and cerebellar cortical spines is suggested to account for differences.
Journal Article•
TL;DR: It was found that the heat treatment of amaranth increased the body weight gain of rats even when the animals consumed diets containing only 10% crude protein, which suggests the presence of a heat-labile antinutritive compound.
Abstract: Two experiments were carried out on rats to determine the nutritional value of raw and autoclaved amaranth (Amaranthus retroflexus) seeds. The test groups of the first experiment were fed only ground amaranth seed. The control group received pure maize meal. Both test groups showed higher growth rate than the control group, due to the higher protein content of amaranth. The final body weight of rats fed autoclaved amaranth seed significantly exceeded that of rats fed raw amaranth seed. The Net Protein Utilisation (NPU) index of raw and autoclaved amaranth was determined in the second experiment. The diets had 10% crude protein concentration and the only protein source was the meal of raw and autoclaved amaranth seed. It was found that the heat treatment of amaranth increased the body weight gain of rats even when the animals consumed diets containing only 10% crude protein. The feed consumption was also higher with the diet containing autoclaved seeds. Despite the finding that there was no significant difference in the NPU index, data suggest the presence of a heat-labile antinutritive compound.
TL;DR: Changes in serum LH and testosterone concentrations and in scrotal surface temperature (SST) following GnRH treatment and to predict the number of spermatozoa collected and the proportion that were viable were determined.
TL;DR: The results suggest that the attachment of fimbriated E. coli strains which were capable of binding to rumen cells was more likely to be dependent on differentiation than the host specificity of the bacteria.
TL;DR: It is concluded from this study that complex, continuously distributed neural traits can successfully be subjected to QTL introgression, and the results raise the possibility that the RQI method can be efficiently applied for gene mapping of complex neural and behavioral traits even if their phenotypic expression is sensitive to confounding developmental and environmental variations.
Abstract: One of the significant factors that affect brain dopamine function is the activity of tyrosine hydroxylase (TH), the first and rate-limiting enzyme in catecholamine biosynthesis. For the analysis of the genetically determined role of dopamine function and TH in behavior and in the regulatory mechanisms of the mesotelencephalic dopamine system we devised a novel genetic strategy (Vadasz; Mouse Genome 88:16–18; 1990). We hypothesized that phenotypic introgression and recombinant fixation could ensure the transfer of Quantitative Trait Loci (QTL) from one strain onto the genetic background of another strain, and new, genetically very similar quasi-congenic strains could be created that would carry individual QTLs, or QTLs in various combinations. Here we summarize the construction of the first set of QTL Introgression strains, and present evidence that QTLs that are responsible for the continuous variation of mesencephalic tyrosine hydroxylase activity (TH/MES), have been transferred onto the C57BL/6By (B6) strain background from BALB/cJ (C) and CXBI (I) donor strains with high and low TH/MES, respectively. The QTL transfer was carried out in two directions by repeated backcross-intercross cycles with concomitant selection for the extreme high and low expressions of TH/MES in replicates, resulting in four QTL Introgression lines. Analysis of regional brain TH activities in the course of the QTL introgression indicated that (a) TH activity in B6.I lines showed quite limited heritability, (b) TH/MES was not highly correlated with striatal TH, and (c) the control of hypothalamic and olfactory tubercle TH activities was largely independent from that of TH/MES. Examination of the open-field (OF) behavior data demonstrated that TH activity did not correlate significantly with OF behavior. After 5 backcross-intercross cycles, TH/MES in each replicate line was still significantly different from that of the B6 background strain. A genomewide scanning of microsatellite markers in the QTL introgression lines demonstrated that about 96% of the markers were of background (B6) type. These results indicate the successful transfer of TH/MES QTLs. After the QTL transfer phase of the experiment altogether more than 100 new RQI strains were initiated in the QTL Introgression lines by strict brother × sister mating. After fixing the introgressed QTLs, ten of the inbred RQI strains were tested for TH/MES. The results showed that in one of the new RQI strains TH/MES was restored to a level that is characteristic to the C donor strain, while TH/MES values in some other strains were between those of the background and donor strains, confirming our hypothesis that phenotypic introgression and recombinant fixation can ensure a virtually complete transfer of QTLs. We conclude from this study that complex, continuously distributed neural traits can successfully be subjected to QTL introgression, and the results raise the possibility that the RQI method can be efficiently applied for gene mapping of complex neural and behavioral traits even if their phenotypic expression is sensitive to confounding developmental and environmental variations, genetic interactions, and genotype-environment interactions.
TL;DR: Treatment with GnRH and assessment of scrotal surface temperature and plasma testosterone concentrations have some correlation with the semen production in the mature bull.