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At least 127 records · Page 7Linked to original sources
PubMed1982

Vanadium metabolism in sheep. I. Comparative and acute toxicity of vanadium compounds in sheep.

Twelve Florida native wethers were given ammonium metavandate, calcium orthovanadate and calcium pyrovanadate by capsule in a study to examine the toxicity of the compounds. The initial daily dosage of 100 mg elemental vanadium was increased by 50 mg at 2-d intervals for an assessment not only of the toxic effects, but also to determined the amount that caused a decline in feed intake to 25% of that of control animals. The initial decline in feed intake was observed at 400 to 500 mg vanadium/d (9.6 to 12 mg/kg body weight, 310 to 350 ppm); a rapid decline in feed intake was accompanied by diarrhea. One sheep fed 550 mg vanadium as calcium orthovanadate died 3 d after dosing. One animal on each of the other three treatments was killed and necropsied for immediate comparison. Extensive mucosal hemorrhage of the small intestine and diffuse or petechial subcapsular hemorrhages of the kidneys were observed for sheep fed all compounds. The three vanadium compounds appeared to be similar in toxicity, as determined by abrupt declines in feed intake and pathological changes of the intestine and kidney. For a determination of acute toxicosis, three sheep were given 40 mg/kg body weight of vanadium as NH4VO3 in gelatin capsules and two sheep were included as controls. Two of the treated animals died within 80 h after administration and the other three were killed at 96 h. Vanadium content of kidney, liver, bone, spleen, lung and muscle was elevated by treatment.

Acute Disease↗
PubMed1982

Fatal pneumonia of bighorn sheep following association with domestic sheep.

During 1979-1980 acute fibrinopurulent bronchopneumonia resulted in high mortality or total loss of herds of bighorn sheep (Ovis canadensis) in California and Washington. Contact with domestic sheep occurred shortly before the onset of disease in each case. Circumstantial evidence indicated that the apparently healthy domestic sheep transmitted pathogenic bacteria to the bighorns, resulting in mortality. Pasteurella multocida and Corynebacterium pyogenes were isolated from pulmonary tissue of dead bighorns. The presence of domestic sheep may have been an important stress which initiated or compounded the disease.

Animal Population Groups↗
PubMed1988

Experimental contact transmission of Pasteurella haemolytica from clinically normal domestic sheep causing pneumonia in Rocky Mountain bighorn sheep.

Two Rocky Mountain bighorn lambs (Ovis canadensis canadensis) were held in captivity for 120 days before being housed with two domestic sheep. The lambs were clinically normal and had no Pasteurella spp. on nasal swab cultures. The domestic sheep were known to carry Pasteurella haemolytica biotype A in the nasal passages. After being in close contact for 19 days. P. haemolytica biotype A was cultured from nasal swabs of one of the bighorn lambs. By 26 days, both bighorn sheep developed coughs, were anorectic and became lethargic and nasal swabs yielded P. haemolytica biotype T, serotype 10. Twenty-nine days after contact, the lambs were necropsied and found to have extensive fibrinous bronchopneumonia. From affected tissues pure cultures of beta-hemolytic P. haemolytica biotype T, serotype 10 were grown. Both domestic sheep remained clinically normal and had no gross or microscopic lesions, but they carried the same P. haemolytica serotype in their tonsils. Behavioural observations gave no indication of stress in the bighorn lambs.

Animals↗
PubMed2000

[Blood gas values in healthy sheep and in sheep with lung diseases] .

In 24 healthy and 101 sheep with different lung diseases like catarrhalic pneumonic bronchopneumonia, lung abscesses, lung worm infections, Maedi and Sheep Pulmonary Adenomatosis (SPA) in arterial and venous samples blood gas analysis was performed. The alveolo-arterial-oxygen-difference was the most sensitive parameter to detect impaired ventilation, it was 11.40 +/- 6.39 mm Hg in healthy sheep. Global insufficiency occurred mainly in sheep with SPA and in mixed infections of SPA with Maedi.

Abscess↗
PubMed1988

[Fecal surveys in pastured sheep and the occurrence of Cysticercus tenuicollis in slaughtered sheep].

Out of 4 fenced pastures, 2 stationary flocks and 3 wandering flocks with approx. 2,000 mother sheep, 962 samples of faeces were checked for the occurrence of gastro-intestinal nematodes and lungworms. Irrespective of the way the sheep are kept, an infestation incidence of 11.1 to 100% with gastro-intestinal nematodes was found. In one flock even after two treatments 66.7% were still infected; therefore, suspect methods of treatment have to be avoided and a constant change of anthelmintics is absolutely essential. Dictyocaulus filaria occurred in 6 out of 9 flocks and was easy to be treated chemotherapeutically, whereas the protostrongyles could be reduced but were not eliminated totally. - 785 out of 4,710 slaughter sheep (= 16.7%) harboured metacestodes of Taenia hydatigena in the omentum majus. In most cases one or two specimens (= 66.6 i.e. 17.6%) of Cysticercus tenuicollis could be found, once there were even 117. 1.332 cysticercus (= 78.1%) showed ready to contract and according to these and other morphological criteria, a total of 1,416 (= 83%) were regarded to be vital and able to evoke an infection. Relating to practice, the sheep dog should always be treated at the same time as deworming of the flock takes place.

Animals↗
PubMed1983

Biliary excretion of infused conjugated sulfobromophthalein in sheep heterozygote for the transport defect present in mutant Corriedale sheep.

Biliary excretion of dye was measured in 2 clinically normal and 2 heterozygote Corriedale sheep (the mutant Corriedale is characterized by depressed biliary transport of conjugated sulfobromophthalein (SBP) compounds) during infusion of the preformed glutathione conjugate of SBP. Maximal rates of excretion of conjugated SBP compounds in bile were comparable in heterozygote Corriedale and clinically normal sheep. These 2 heterozygote sheep do not express the biliary transport defect observed in mutant Corriedale sheep during SBP-glutathione infusion.

Animals↗
PubMed1981

Brain cholinesterases activity in healthy cattle, swine, and sheep and in cattle and sheep exposed to cholinesterase-inhibiting insecticides.

Cholinesterase activity of the cerebrum, brain stem, and cerebellum was measured in cattle, swine, and sheep. Mean activities of the individual brain parts were expressed as micromoles of acetylthiocholine iodide hydrolyzed per minute per gram of brain. Cerebrum values were 3.01, 3.88, and 3.32; brain stem values were 3.42, 4.48, and 3.93; and cerebellum values were 2.36, 2.89, and 6.77 for cattle, swine, and sheep, respectively. The average activity of the 3 brain portions from cattle, swine, and sheep was 2.93, 3.75, and 4.67, respectively. Cholinesterase activity was stable for several days at 25 C and under refrigeration or freezing conditions for longer periods. Cattle and sheep poisoned with organophosphate or carbamate insecticides had cholinesterase depression ranging from near 50% to 80%.

Animals↗
PubMed1999

Amino-terminal sequencing of sheep CD1 antigens and identification of a sheep CD1D gene.

The anti-CD1 monoclonal antibodies IAH-CC14 and SBU-T6 were used to immunopurify CD1 antigens from sheep thymocytes. The amino-terminal sequence of IAH-CC14 yielded 13 amino acids, and 29 amino acids were obtained from the SBU-T6 antigen. The sequence of the IAH-CC14 antigen was 100% identical to the predicted sequence of the sheep CD1B clone, SCD1B-42. The 29 amino acid sequence of the SBU-T6 antigen did not match identically with the derived amino acid sequence of any of the previously reported sheep CD1 genes but had closest similarity to the derived sequence of human CD1E. Degenerate polymerase chain reaction primers based on this sequence identified a group 2 sheep CD1 gene. The predicted amino acid sequence of this gene shows that it is not identical to the SBU-T6 peptide, indicating that a different, CD1D-like gene was cloned.

Amino Acid Sequence↗
PubMed1992

Inter- and intraspecific placentae in sheep, goats and sheep-goat chimaeras.

These studies compared inter- and intraspecific placentae during implantation and at full-term in sheep, goats and interspecific sheep-goat chimaeras. Histological sections prepared from intra- and interspecific day-26, 32 and 36 placentae in ewes and does indicated an altered ability of the trophoblast to invade the maternal caruncle in interspecific pregnancies. Two sheep-in-goat pregnancies were less, and two goat-in-sheep pregnancies were more, invasive than homologous pregnancies. Caprine pregnancies in chimaeras generally terminated before timed samples could be obtained, but biopsy samples collected at laparotomy between days 42 and 48 demonstrated both normal and abnormal placentation in chimaeras after breedings to rams. In six of 11 full-term fetal placentae from ovine pregnancies in chimaeras, there was abnormal retention of maternal caruncular tissue to the extent that macroscopic lesions were visible on the surface of the fetal cotyledons. Histological observations indicated that proliferation of maternal septa and hyalinization of maternal vessels had occurred at the expense of the fetal villi. Overall, the results suggested that the physiological events that regulate implantation are different in the two species, despite anatomical similarities between the ovine and caprine placenta. The caprine conceptus is likely to be rejected in the ovine or chimaeric uterus because of its over-invasiveness in the early stages of implantation, whereas the ovine conceptus can survive in the potentially chimaeric uterus.

Animals↗
PubMed1996

T cell subsets and Langerhans cells in the forestomach mucosa of adult sheep and sheep foetuses.

As part of a study on leukocytes in the ruminant forestomach the occurrence and distribution of T cells and major histocompatibility complex Class II positive (MHC-II+) cells in the forestomach mucosa of sheep were investigated. Samples were taken from the reticulum, atrium ruminis, ventral rumen, dorsal rumen and omasum of five healthy adult ewes and seven nearly fullborne foetuses. Frozen sections were stained with an indirect immunoperoxidase method using monoclonal antibodies against sheep MHC-II, CD4 and CD8 molecules and the sheep gamma delta T cell receptor. Both MHC-II+ cells and T cells were distributed along the basal lamina of the epithelium, with either mainly intraepithelial (CD8+ and gamma delta +cells) or mainly subepithelial (MHC-II+ and CD4+ cells) location. The MHC-II+ cells showed dendritic morphology and were interpreted as Langerhans cells. In adults ewes CD4+T cells comprised the major T cell subset at all sample sites. The number of T cells declined from the atrium ruminis through the ventral rumen to the dorsal rumen, while the number of Langerhans cells showed no marked variation between different sample sites. In foetuses, Langerhans cells showed a relatively high prevalence, while T cells were sparse and showed a more random distribution in the rumen wall. No marked variation between sample sites were observed in the fetal forestomachs. It is concluded that Langerhans cells and T cells are normally present in the forestomach mucosa of sheep, and it is suggested that the Langerhans cells represent a constituent component, while the prevalence and distribution of T cells may be influenced by antigen leakage through the epithelium.

Animals↗
PubMed1999

Sheep perforin: identification and expression by gammadelta T cells from pregnant sheep uterine epithelium.

GammadeltaTCR-positive intraepithelial lymphocytes (IEL) in sheep uterus have been shown in previous studies to express CD8 and to contain prominent intracytoplasmic granules, indicating that they may be cytotoxic. Sheep perforin, which has not previously been described, was identified in the present study using RT-PCR based on primers from human and mouse perforin sequences. A 290 base pair (bp), partial sheep perforin sequence was obtained which showed 80.3% and 66.2% nucleotide identity with human and mouse perforin, respectively. GammadeltaTCR+ IEL from sheep pregnant uteri were found to express perforin mRNA providing further evidence that these cells are cytotoxic.

Animals↗
PubMed1997

Molecular cloning of sheep and goat ferredoxin reductase messenger ribonucleic acids, and identification of an alternatively spliced form of sheep ferredoxin reductase.

Complementary DNA clones of mRNAs for sheep and goat NADPH-ferredoxin reductases (ferredoxin NADP+ oxidoreductase, EC 1.18.1.2) were isolated by the reverse transcriptase polymerase chain reaction method, and the complete nucleotide sequences of the coding and 3'-flanking regions of these cDNA clones were determined. Comparative analysis using the deduced amino acid sequences of NADPH-ferredoxin reductases clarified the interspecific conservation of the ferredoxin-binding and flavin adenine dinucleotide (FAD)-binding regions, confirming the results reported previously. During this study, we happened to identify an alternatively spliced mRNA that completely lacks exon 3, just adjacent to the FAD-binding region of the sheep NADPH-ferredoxin reductase cDNA clone. In the screening of other alternatively spliced mRNAs of NADPH-ferredoxin reductases derived from several steroidogenic organs, such as adrenocortices, testes, and ovaries of sheep and goats, only one kind of alternatively spliced mRNA as described above was detected in sheep adrenocortices. Then, we constructed Escherichia coli expression systems for these two forms of mRNA and analyzed their enzymatic properties. We found that the ability of the alternatively spliced NADPH-ferredoxin reductase protein to transfer electrons to ferredoxin is completely abolished because FAD binding is inhibited.

Alternative Splicing↗
PubMed1996

The effects of propofol on hemodynamics and renal blood flow in healthy and in septic sheep, and combined with fentanyl in septic sheep.

Sepsis is characterized by myocardial depression and systemic vasodilation, both of which are most likely mediated by nitric oxide. Propofol inhibits nitric oxide synthase and may therefore be beneficial in sepsis. On the other hand, renal blood flow, known to be only minimally affected by propofol in healthy subjects, may be drastically reduced in septic individuals, because the renal microvasculature is known to be very sensitive to nitric oxide. In this study, the effects of propofol in healthy and in septic sheep, and in combination with fentanyl, were analyzed and compared with nonanesthetized septic sheep. In healthy sheep, propofol caused only minor hemodynamic changes. In septic sheep, however, hemodynamics deteriorated. Renal blood flow was reduced to 60% +/- 10% of the preseptic baseline and to 39% +/- 4% of the septic value. This reduction was selective, since the cardiac output decreased significantly less. These adverse effects of propofol on hemodynamics and renal blood flow were reduced when propofol was combined with fentanyl.

Adjuvants, Anesthesia↗
PubMed1985

Sheep histocompatibility antigens: a population level comparison between lymphocyte antigens previously defined in France, England and Scotland, and sheep red cell groups.

A comparison test was performed to look for correlations between the three nomenclature systems for sheep histocompatibility antigens which have been previously described in France, England and Scotland. 187 French sheep from a wide variety of breeds were typed for lymphocyte antigens with antisera which detect the OLA, P and ED series of antigens; they were also tested against 387 uncharacterized French antisera. Six clusters of sera were found which showed correspondence between antigens of at least two of the three nomenclatures; five of these clusters gave high r values of 0.78-0.94. New antisera from French sheep were found which contributed to the above clusters but few additional clusters were noted. No correlation was found between any of the lymphocyte groups of antisera tested and the sheep red cell antigens which were also tested.

Animals↗
PubMed1996

Characterization and linkage mapping of ten sheep microsatellite markers derived from a sheep x hamster cell hybrid.

A cosmid library has been constructed from a sheep x hamster cell hybrid containing sheep chromosome t1, rob (6;24). Clones containing sheep DNA were identified by hybridizing to a total sheep genomic DNA probe. Small fragments (< 500 bp) containing (AC)n microsatellites were subcloned and sequenced. Ten microsatellite markers were characterized and six were mapped back to chromosomes 6 and 24. The remaining microsatellites mapped to chromosome 26, which was shown to be present in a small proportion of cells of the cell line.

Animals↗
PubMed1978

Identification of enterotoxigenic staphylococci from sheep and sheep cheese.

The total of 127 Staphylococcus aureus strains obtained from sheep and sheep cheese were examined for their biochemical activities, biotypes, phage patterns, and ability to produce enterotoxins. Of the 83 staphylococcal strains isolated from animals 77 (93%) were classified as the C biotype. Of this group of sheep-adapted strains, 61 (79%) were sensitive to phage 78, and 46 (60%) produced enterotoxin C exclusively. The three isolated belonging to the A biotype produced enterotoxin D, and two of the three unclassifiable strains produced enterotoxin A. Of the 44 staphylococcal strains isolated from sheep cheese, there were 37 (84%) identified as the C biotype. From this series, 31 (84%) strains were lysed with phage 78, 6 (16%) strains produced enterotoxin C, and 1 strain produced enterotoxin A. One of the six strains determined as the A biotype produced enterotoxin D. C biotype strains, especially of ovine origin, are an exception among animal staphylococci, because a large number of them are enterotoixgenic. The C antigenic type is the most usual of the known enterotoxins in staphylococci of animal provenance.

Animals↗
PubMed1999

Jaagsiekte sheep retrovirus is necessary and sufficient to induce a contagious lung cancer in sheep.

Sheep pulmonary adenomatosis (SPA) is a contagious and experimentally transmissible lung cancer of sheep resembling human bronchiolo-alveolar carcinoma. A type D retrovirus, known as jaagsiekte sheep retrovirus (JSRV), has been associated with the etiology of SPA, but its exact role in the induction of the tumor has not been clear due to the lack of (i) a tissue culture system for the propagation of JSRV and (ii) an infectious JSRV molecular clone. To investigate the role of JSRV in the etiology of SPA, we isolated a full-length JSRV proviral clone, pJSRV21, from a tumor genomic DNA library derived from a natural case of SPA. pJSRV21 was completely sequenced and showed open reading frames in agreement with those deduced for the original South African strain of JSRV. In vivo transfection of three newborn lambs by intratracheal inoculation with pJSRV21 DNA complexed with cationic lipids showed that pJSRV21 is an infectious molecular clone. Viral DNA was detected in the peripheral blood mononuclear cells (PBMCs) of the transfected animals by a highly sensitive JSRV-U3 heminested PCR at various time points ranging from 2 weeks to 6 months posttransfection. In addition, proviral DNA was detected in the PBMCs, lungs, and mediastinal lymph nodes of two lambs sacrificed 9 months posttransfection, but no macroscopic or histological SPA lesion was induced. We prepared JSRV particles by transient transfection of 293T cells with a JSRV construct (pCMV2JS21) in which the upstream U3 was replaced with the cytomegalovirus early promoter. Four newborn lambs were inoculated with JSRV21 particles produced in this manner, and two of them showed the classical signs of SPA 4 months postinfection. The resulting tumors were positive for JSRV DNA and protein. Thus, JSRV21 is an infectious and pathogenic molecular clone and is necessary and sufficient to induce sheep pulmonary adenomatosis.

Animals↗
PubMed2001

Estimation of cumulative exposure to organophosphate sheep dips in a study of chronic neurological health effects among United Kingdom sheep dippers.

OBJECTIVES: To derive a method for retrospectively estimating cumulative exposure to organophosphate (OP) pesticides among a cross section of United Kingdom sheep dippers, as part of a wider epidemiological study of neurological abnormality within this group of workers. METHODS: A hygiene study of dipping sessions at 20 farms using diazinon based dips was carried out by two experienced occupational hygienists. Observations on the exposure of people to concentrate and dilute dip were recorded throughout each dipping session, together with the other relevant factors including the use and condition of protective clothing. Concentrations of urinary metabolites of diazinon were used to measure actual exposure to OPs. To estimate exposure in the subsequent epidemiological study, an occupational exposure history questionnaire was developed using results from the hygiene study and an empirical exposure model. RESULTS: In the hygiene study, increased urinary metabolites were associated with the handling of concentrate dip and exposure to dilute dip wash through splashing. Very few dippers wore the recommended protective clothing. The handling of concentrate dip was the principal source of exposure to OPs. Dipping task was used as a surrogate for splashing of dilute dip in retrospective exposure estimation. In the epidemiological study, cumulative exposure to OP sheep dips was highly correlated with the total number of dipping days, but not with age. CONCLUSIONS: Sheep dip concentrate is the most important source of OP exposure among sheep dippers and estimates of exposure to OPs during routine dipping should take due account of exposure to concentrate dip as well as to the dilute dip wash. The observed use of recommended protective clothing by most subjects was insufficient to allow a proper empirical assessment of its effectiveness.

Agricultural Workers' Diseases↗