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Development of pneumonia in desert bighorn sheep after exposure to a flock of exotic wild and domestic sheep.

From 1986 to 1989, 5 desert bighorn sheep (3 Ovis canadensis mexicana and 2 O c nelsoni), ranging in age from 2 to 3 years, were exposed to a flock of exotic wild and domestic sheep to potentially achieve naturally acquired pneumonia. Pasteurella multocida was isolated from nasal samples from 4 of 6 sheep randomly sampled from the flock. Bighorn sheep were exposed individually and each exposure period was a trial. Treatment before and after exposure varied and included combinations of alpha interferon, antibiotics, anti-inflammatory drugs, and vaccines. Treatments were chosen on the basis of recommendations of others for treating pneumonia in desert bighorn sheep as well as our own experience in sheep and cattle. Regardless of treatment used, bighorn sheep in trials 1 to 4 developed signs of pneumonia within 10 to 14 days of exposure. Bighorn sheep in trials 1 to 3 died within 11 to 17 days of initial exposure. In trial 4, the bighorn sheep was isolated from the carrier sheep for treatment of pneumonia on day 14 and died on day 30. Pasteurella multocida was isolated from lung tissue in 3 of the 4 bighorn sheep. On the basis of results of trials 1 to 4, a more in depth clinical study was conducted in trial 5. Nasal and blood specimens were collected prior to and during trial 5 for bacteriologic culturing and serologic testing for bovine viral diarrhea virus, infectious bovine rhinotracheitis, parainfluenza-3 virus, and respiratory syncytial virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

The effect of insulin-like growth factor 1 incorporated into a hyaluronic acid-based nasal pack on nasal mucosal healing in a healthy sheep model and a sheep model of chronic sinusitis.

BACKGROUND: Endoscopic sinus surgery (ESS) is the accepted surgical treatment for chronic refractory rhinosinusitis. Prolonged healing and adhesion formation remain common problems. This study investigates the use of a hyaluronic acid-based pack impregnated with insulin-like growth factor (IGF) 1 to facilitate more rapid and effective healing after ESS in a healthy sheep model and a sheep model of chronic sinusitis. METHODS: This study used 12 healthy sheep and 9 sheep with chronic sinusitis. In each sheep one side (computer randomized) was used as a control. Under endoscopic guidance, mucosal injuries and adhesions were created on both sides and were either packed with a hyaluronic acid pack impregnated with IGF-1 or left unpacked as a control. Serial biopsies were performed for 4 months. RESULTS: In the healthy sheep there was a statistically significant (p < 0.05) improvement in reepithelialization in IGF-1 packed wounds at day 28 (89% for IGF-1 versus 44% for controls). In both healthy sheep and sheep with sinusitis there was no significant difference in mucosal reepithelialization at any of the other measured time points. In the sinusitis group, there was a significant decrease in ciliary regeneration at day 56 in the Merogel/IGF-1 group compared with the control group: 59.20% versus 77.68% (p < 0.01) and at day 112, 69.70% versus 87.26% (p < 0.01). CONCLUSION: Hyaluronic acid impregnated with IGF-1 improved reepithelialization in the healthy sheep but not in the sheep with chronic rhinosinusitis. These packs had a detrimental effect on mucosal ciliary regeneration in the sheep with chronic rhinosinusitis.

Administration, Topical↗

Jaagsiekte sheep retrovirus can be detected in the peripheral blood during the pre-clinical period of sheep pulmonary adenomatosis.

Peripheral blood leukocytes (PBLs) and tissue samples from 36 sheep were examined for jaagsiekte sheep retrovirus (JSRV) by hemi-nested PCR. Animals were classified according to the status of sheep pulmonary adenomatosis (SPA), which was confirmed by pathological examination, as follows: (i) sheep with classical SPA (cSPA, n=10), (ii) sheep with atypical SPA (aSPA, n=6), (iii) non-affected sheep from SPA-affected flocks (in-contact, n=10) and (iv) non-affected sheep from SPA-free flocks (control, n=10). JSRV proviral DNA was detected in the PBLs of 10/10 cSPA, 5/6 aSPA, 4/10 in-contact and 0/10 control sheep. Lung tumours and lymphoid organs were also found to be JSRV-positive. The number of positive PCR results was greater for sheep in the cSPA group than for those in the aSPA and in-contact groups. For the first time, it is concluded that JSRV can be detected in naturally infected sheep before the onset of clinical disease and even before the development of discernible tumours.

Animals↗

Chromosomal distribution of endogenous Jaagsiekte sheep retrovirus proviral sequences in the sheep genome.

A family of endogenous retroviruses (enJSRV) closely related to Jaagsiekte sheep retrovirus (JSRV) is ubiquitous in domestic and wild sheep and goats. Southern blot hybridization studies indicate that there is little active replication or movement of the enJSRV proviruses in these species. Two approaches were used to investigate the distribution of proviral loci in the sheep genome. Fluorescence in situ hybridization (FISH) to metaphase chromosome spreads using viral DNA probes was used to detect loci on chromosomes. Hybridization signals were reproducibly detected on seven sheep chromosomes and eight goat chromosomes in seven cell lines. In addition, a panel of 30 sheep-hamster hybrid cell lines, each of which carries one or more sheep chromosomes and which collectively contain the whole sheep genome, was examined for enJSRV sequences. DNA from each of the lines was used as a template for PCR with JSRV gag-specific primers. A PCR product was amplified from 27 of the hybrid lines, indicating that JSRV gag sequences are found on at least 15 of the 28 sheep chromosomes, including those identified by FISH. Thus, enJSRV proviruses are essentially randomly distributed among the chromosomes of sheep and goats. FISH and/or Southern blot hybridization on DNA from several of the sheep-hamster hybrid cell lines suggests that loci containing multiple copies of enJSRV are present on chromosomes 6 and 9. The origin and functional significance of these arrays is not known.

Animals↗

Cloning and comparison of bighorn sheep CD18 with that of domestic sheep, goats, cattle, humans and mice.

Previously, we have shown that CD18, the beta-subunit of beta(2)-integrins, serves as a receptor for leukotoxin (Lkt) secreted by Mannheimia (Pasteurella) haemolytica on bovine leukocytes. Anti-CD18 monoclonal antibodies (mAbs) inhibit Lkt-induced cytolysis of bighorn sheep (Ovis canadensis) leukocytes suggesting that CD18 may serve as a receptor for Lkt on the leukocytes of this species as well. Confirmation of bighorn sheep CD18 as a receptor for Lkt, and elucidation of the enhanced Lkt-susceptibility of bighorn sheep polymorphonuclear leukocytes (PMNs), necessitates the cloning and sequencing of cDNA encoding bighorn sheep CD18. Hence, in this study we cloned and sequenced the cDNA encoding CD18 of bighorn sheep, and compared with that of other animal species. The cDNA of bighorn sheep CD18 has an open reading frame (ORF) of 2310bp. CD18 sequences obtained individually from peripheral blood mononuclear cells (PBMCs) and PMNs were identical to each other. Comparison of the deduced 770-amino acid sequence of CD18 of bighorn sheep with that of domestic sheep, goats, cattle, humans and mice revealed 99, 98, 95, 82 and 80% identity, respectively. Availability of cloned bighorn sheep CD18 cDNA should allow the molecular characterization of M. haemolytica Lkt-receptor interactions in bighorn sheep and other ruminants that are susceptible to this disease.

Amino Acid Sequence↗

Vaccination of sheep against larvae of the sheep blowfly (Lucilia cuprina).

Four first stage larval antigens from the sheep blowfly were identified using supernatants from cultures of antibody secreting cells. These partially purified larval antigens, when added to Montanide ISA-25 containing recombinant ovine IL-1 beta (rovIL-1 beta) were used to successfully vaccinate sheep against larvae of the sheep blowfly. Significantly less strikes were recorded on vaccinated sheep compared to controls (P < 0.033) with surviving larvae from vaccinated sheep up to 85% smaller than larvae from control sheep. RovIL-1 beta was found to be an important component of the vaccine. Vaccinated sheep showed both humoral and cellular immune responses to the larval antigens. Antibody levels generally correlated directly with delayed-type hypersensitivity (DTH) responses, but neither antibody nor DTH correlated positively with protection in vaccinated sheep. Skin sections removed from individual sheep immediately after challenge revealed aggregations of CD4+, gamma delta-TCR+ and CD1+ cells located directly under the epidermis in vaccinated sheep.

Animals↗

Characterization of the sheep apolipoprotein E (ApoE) gene and allelic variations of the ApoE gene in scrapie Suffolk sheep.

Apolipoprotein E (ApoE) plays a central role in lipid transport and is suggested to be involved in neuronal repair. Human ApoE epsilon 4 allele is known as a risk factor for Alzheimer's disease, and an association of the human ApoE genotype with the human prion disease, Creutzfeldt-Jakob disease, is suggested, albeit controversial. We analyzed the sheep ApoE gene to determine whether any association between the sheep ApoE genotype and the sheep prion disease, scrapie, existed. The sheep ApoE cDNA contained an open reading frame (ORF) consisting of 948 base pairs (bp) that encoded 316 amino acids (aa). The sheep ApoE gene was composed of four exons separated by three introns, and the ORF was encoded by three exons, designated exons 2, 3, and 4. Nucleotide sequence analysis also showed the presence of one G/T nucleotide polymorphism in the ORF that resulted in an Ala/Ser amino-acid substitution at codon 258. PCR-restriction fragment length polymorphism analysis of genomic DNA showed the presence of three sheep ApoE genotypes that were the result of the homologous and heterologous combinations of the two alleles. We analyzed the sheep ApoE genotypic and the allelic frequencies in scrapie and control Suffolk sheep, but they did not significantly differ from those in the control sheep, even though PrP genotype-matched populations were compared. The ApoE genotype appeared not to be associated with the progression of the disease when looking at the age at death. These results indicated that in Suffolk sheep, none of the ApoE genotypes was associated with scrapie.

Alleles↗

New Zealand sheep with scrapie-susceptible PrP genotypes succumb to experimental challenge with a sheep-passaged scrapie isolate (SSBP/1).

Scrapie does not occur in New Zealand (NZ), although PrP gene alleles associated with susceptibility to the disease are found at relatively high frequencies in NZ sheep. The hypothesis that scrapie is a genetic disease of sheep is thus unlikely to be true. To confirm that NZ sheep are actually susceptible to scrapie infection, NZ sheep of various PrP genotypes were challenged by subcutaneous inoculation with a sheep-passaged scrapie isolate (SSBP/1). Showing similar PrP genetics to that seen in UK sheep, all NZ sheep carrying the VRQ PrP allele developed clinical signs typical of scrapie, with characteristic neurodegenerative changes and PrP(Sc) evident on histopathological examination of their brains and lymphoid tissues. The incubation periods recorded in NZ sheep were generally shorter than those found in UK sheep. The results confirm that New Zealand sheep are as susceptible as their UK counterparts to experimental scrapie infection by subcutaneous inoculation.

Animals↗

A comparative study of feeding behavior and digestive function in dairy goats, wool sheep and hair sheep.

An intake and digestibility study was conducted with three groups (six animals per group) of yearling wether dairy goats (four Toggenburg, two Alpine), wool sheep (Targhee X Dorset) and hair sheep (St. Croix). Body weight (BW) ranged from 42 to 52 kg, averaging 47 kg. All animals were penned individually and given ad libitum access to a mixture of alfalfa-smooth bromegrass hay in pelleted, chopped or long form. Each group contained three ruminally cannulated animals. There were no apparent differences in the composition of feed consumed among goats, wool sheep and hair sheep, and no significant animal type X forage form interactions for any of the variables evaluated. Significant differences were observed in dry matter intake (DMI) between wool sheep, hair sheep and goats: 3.17%, 2.66% and 2.23% of BW, respectively (P less than .05). Daily water intake (WI) was greatest for wool sheep (P less than .05), but not different between hair sheep and goats. Total digestibility of dry matter (DM) and all fiber fractions were similar among animal types. For the cannulated animals, ruminal content weight and total ruminal volume were greatest for wool sheep (P less than .05). Ruminal acid detergent lignin (ADL) turnover was greater in wool and hair sheep than goats (P less than .05), but no differences were apparent for dry matter or neutral detergent fiber (NDF) turnover. For all animals, DMI, DMI/BW, digestible DMI and WI were greater for pelleted than chopped and long hay (P less than .05). Total ruminal volume, contents weight (on an absolute or BW basis) and fluid volume were lower in the cannulated animals consuming pelleted hay (P less than .05). Ruminal DM turnover rate was faster on pelleted than long hay, while DM turnover rate on chopped hay was intermediate. Turnover of ADL was faster on pelleted than chopped or long hay (P less than .05), but there were no differences among forage forms in NDF turnover rate. Fluid turnover rate was faster on pelleted and chopped than on long hay (P less than .05). Under the conditions of this study, no apparent differences were observed among animal types in the nutrient composition of feed consumed, ruminal or total tract digestibilities or rate of passage for dry matter. However, feeding behavior or selectivity differences under natural grazing conditions may deviate from what has been observed in confinement.

Animals↗

Rosetting of human T lymphocytes with sheep and human erythrocytes. Comparison of human and sheep ligand binding using purified E receptor.

Previous studies have shown that the purified T lymphocyte glycoprotein, cluster differentiation 2 (CD2) (also known as T11, lymphocyte function-associated antigen (LFA)-2, and the erythrocyte (E) rosette receptor) interacts with the LFA-3 molecule on human E. We have examined the interaction of the purified CD2 molecule with the T11 target structure (T11TS) molecule on sheep E, and compared the two interactions. Purified, 125I-labeled CD2 bound to sheep E and the binding was inhibited by anti-T11TS monoclonal antibody (mAb). Reciprocally, the binding of T11TS mAb to sheep E was inhibited by pretreatment of sheep E with purified CD2. High concentrations of purified CD2 aggregated sheep E, possibly by inserting into the membrane, and the aggregation was inhibited by T11TS mAb. The affinity and number of binding sites for purified CD2 on sheep and human E was found to be similar, with Ka of 9 X 10(7)/M and 6 X 10(7)/M and 9800 and 8300 CD2 binding sites/E, respectively. Thus, the human T lymphocyte CD2 molecule is a receptor that cross-reacts between LFA-3 on human E and T11TS on sheep E, suggesting that LFA-3 and T11TS are functionally homologous ligands. As measured by saturation mAb binding, there are 8100 and 3900 ligand molecules/sheep and human E, respectively. Human and sheep E have surface areas of 145 and 54 micron 2, respectively. The 3.2- to 5.6-fold higher ligand density on sheep E appears to account for the ability of sheep but not human E to rosette with certain types of human T lymphocytes.

Animals↗

Guinea pig antibody to C3 component of the sheep complement produced by immunization with a heat-inactivated sheep serum--alcian blue complex.

Normal sheep serum or serum heated at 56 degrees C for 30 min were added to alcian blue solutions. The optical density of alcian blue-heated sheep serum complexes formed were 2-4 times greater than those obtained with unheated serum. Most guinea pigs immunized with alcian blue-heated sheep serum complexes produced antibodies that precipitated the third component (C3) of sheep complement (C') from electrophoresed sheep serum. These antisera also hemagglutinated sheep erythrocyte--rabbit antibody complexes treated with sheep serum (C'). Guinea pigs immunized with alcian blue-normal sheep serum complexes did not react with electrophoresed sheep serum nor with sheep C' in the hemagglutination test.

Alcian Blue↗

Unique long terminal repeat U3 sequences distinguish exogenous jaagsiekte sheep retroviruses associated with ovine pulmonary carcinoma from endogenous loci in the sheep genome.

Ovine pulmonary carcinoma (OPC) is a contagious lung cancer of sheep that is presumed to be caused by an exogenous retrovirus of sheep, jaagsiekte sheep retrovirus (JSRV). The sheep genome carries 15 to 20 copies of endogenous sheep retrovirus (ESRV) loci that hybridize to JSRV DNA probes. In order to clarity the etiologic roles of ESRV and an exogenous JSRV-like retrovirus (exJSRV) in OPC, we assessed sequence differences between ESRV and JSRV. Molecular characterization of six ESRV loci revealed restriction sites specific for JSRV. Nucleotide sequences of ESRVs from sheep of different breeds were similar to those of JSRV in structural genes but divergent in U3. Therefore, primers specific for the U3 sequences of exJSRV were designed for use in the PCR. Of 13 tumor DNAs tested by PCR with these exogenous-virus U3 primers, 8 produced DNA fragments that hybridized with the JSRV gag probe, but neither lung DNAs from healthy sheep nor DNAs from nontumor tissues of diseased sheep produced similar DNA fragments. exJSRV PCR products from tumor DNAs of sheep with OPC from three continents had restriction profiles similar to each other but different from those of ESRVs upon digestion with EcoRI, HindIII, NdeI, KpnI, and ScaI. These exjSRVs could be classified into two genotypes according to U3 sequences and restriction profiles. U3 sequences of exJSRV proviruses in tumors strongly resembled those of JSRV but differed from those of ESRVs, suggesting that exJSRVs, rather than ESRVs, are primarily associated with oncogenesis in OPC.

Amino Acid Sequence↗

Susceptibility of Rocky Mountain bighorn sheep and domestic sheep to pneumonia induced by bighorn and domestic livestock strains of Pasteurella haemolytica.

Bighorn sheep were inoculated intratracheally with suspensions of nonhemolytic Pasteurella haemolytica biotype T (10(12) organisms) unique to wild bighorns, with beta-hemolytic P. haemolytica biotype T (10(12) organisms) isolated from clinically normal domestic sheep or intradermally with half a dose of a cattle vaccine containing P. haemolytica biotype A (10(5) organisms). The bighorn strain caused lobar necrotizing bronchopneumonia whereas both domestic livestock strains precipitated fatal septicemia and fibrinous bronchopneumonia. The serotypes given were T3, T4, T15 and A1 and these were recovered from lung lesions and other organs. In three trials, domestic sheep were inoculated intratracheally with suspensions of bighorn sheep pneumonic lungs, and two concentrations of the P. haemolytica bighorn strain (10(4) and 10(12) organisms). One of these sheep was inoculated intrabronchially. The domestic sheep experienced a transient fever and elevated white blood cell counts. After six days, none of the sheep had lung lesions and inoculated organisms could not be recovered. It is suggested that bighorn sheep are very susceptible to P. haemolytica from domestic livestock and should not be allowed in contact with sheep or cattle.

Alberta↗

Ketone body and fatty acid metabolism in sheep tissues. 3-Hydroxybutyrate dehydrogenase, a cytoplasmic enzyme in sheep liver and kidney.

1. 3-Hydroxybutyrate dehydrogenase (EC 1.1.1.30) activities in sheep kidney cortex, rumen epithelium, skeletal muscle, brain, heart and liver were 177, 41, 38, 33, 27 and 17mumol/h per g of tissue respectively, and in rat liver and kidney cortex the values were 1150 and 170 respectively. 2. In sheep liver and kidney cortex the 3-hydroxybutyrate dehydrogenase was located predominantly in the cytosol fractions. In contrast, the enzyme was found in the mitochondria in rat liver and kidney cortex. 3. Laurate, myristate, palmitate and stearate were not oxidized by sheep liver mitochondria, whereas the l-carnitine esters were oxidized at appreciable rates. The free acids were readily oxidized by rat liver mitochondria. 4. During oxidation of palmitoyl-l-carnitine by sheep liver mitochondria, acetoacetate production accounted for 63% of the oxygen uptake. No 3-hydroxybutyrate was formed, even after 10min anaerobic incubation, except when sheep liver cytosol was added. With rat liver mitochondria, half of the preformed acetoacetate was converted into 3-hydroxybutyrate after anaerobic incubation. 5. Measurement of ketone bodies by using specific enzymic methods (Williamson, Mellanby & Krebs, 1962) showed that blood of normal sheep and cattle has a high [3-hydroxybutyrate]/[acetoacetate] ratio, in contrast with that of non-ruminants (rats and pigeons). This ratio in the blood of lambs was similar to that of non-ruminants. The ratio in sheep blood decreased on starvation and rose again on re-feeding. 6. The physiological implications of the low activity of 3-hydroxybutyrate dehydrogenase in sheep liver and the fact that it is found in the cytoplasm in sheep liver and kidney cortex are discussed.

Acetoacetates↗

Analysis of mitochondrial DNA indicates that domestic sheep are derived from two different ancestral maternal sources: no evidence for contributions from urial and argali sheep.

To investigate the origins and phylogenetic relationships of domestic sheep, mitochondrial DNA (mtDNA) from 243 sheep of five European, one African, and four Asian breeds and several mouflon (Ovis musimon), urial (O. vignei bochariensis), and argali (O. ammon nigrimontana, O. a. collium) were assayed for restriction fragment length polymorphisms (RFLP). Twenty haplotypes were identified which occurred in three major phlogenetic groups: urial/argali, mouflon/domestic, and domestic sheep. From the branches that contain mouflon and domestic sheep, two major domestic sheep lineages are apparent. One lineage, termed European lineage, contains the majority of haplotypes detected among European domestic sheep. These mtDNAs resemble mouflon haplotypes. The other lineage, termed Asian lineage, consists of haplotypes found in central Asian and some European domestic sheep. The mean sequence difference between these two lineages (0.72%) is of similar magnitude as that between two argali subspecies. To accurately estimate sequence differences between the European and Asian mtDNA types, the mitochondrial control region of one animal from each lineage and of one mouflon and urial were completely sequenced. Sequence comparisons show that Asian and European domestic sheep lineages differ by 4.43%. The mouflon sequences diverges from the Asian type by 4.52%, but by only 1.36% from the European type. Our data supports the hypothesis that some modern domestic sheep and European mouflon derive from a common ancestor and provide evidence of an additional wild ancestor, other than the urial and argali groups, which has yet to be identified.

Africa↗

Identification of beta-adrenergic receptors using [3H]dihydroalprenolol in fetal sheep heart: direct evidence of qualitative similarity to the receptors in adult sheep heart.

The fetal sheep heart responds to beta-adrenergic stimuli; however, in vivo studies show the response of the fetal heart is less than that of the adult heart. We used [3H]dihydroalprenolol (DHA) to study directly beta-adrenergic receptors in heart particulates of fetal sheep at term and adult sheep. [3H]DHA binding to fetal heart particulates was rapid, reversible (t 1/2 = 2.9 +/- 0.3 min), stereoselective, saturable (101.2 +/- 7.4 fmoles/mg protein), and of high affinity (4.8 +/- 0.4 nM). The rank order of agonists competing for [3H]DHA binding was isoproterenol (0.32 +/- 0.10 microM) greater than epinephrine (1.19 +/- 0.23 muM) approximately equal to norepinephrine (2.67 +/- 0.69 muM), which is compatible with beta 1-adrenergic potencies. [3H]DHA also bound to the adult sheep heart in a manner expected for beta 1-receptors. No difference in the binding affinity of [3H]DHA or agonists' competition was demonstrated between the fetal and adult sheep heart. Comparison of the concentration of beta-adrenergic receptors in fetal and adult hearts was confounded by the choice of the denominator for unit expression. The concentration was higher in the adult when expressed as a function of protein content or 5'-nucleotidase activity (0.52 +/- 0.07 versus 1.12 +/- 0.06). However, there was no difference when tissue weight, Na+ - K+-ATPase, or NaF-stimulated adenylate cyclase was used. Furthermore, isoproterenol-stimulated adenylate cyclase and cardiac contractile response to a threshold dose of isoproterenol were identical in the fetal and adult sheep heart. We conclude that beta-receptors can be studied with [3H]DHA in the fetal sheep heart, this receptor is qualitatively similar to the beta-receptor in the adult sheep heart, and it is unlikely that there is a difference in the concentration of beta-adrenergic receptors in fetal and adult sheep heart.

Adenylyl Cyclases↗

[Ecological adaptability of Suffolk sheep and Polled Dosert sheep introduced from Australia to Xinjiang and their hybrid utilization].

The physiological characters, reproductive rate and comprehensive adaptability of Suffolk sheep and Polled Dosert sheep introduced from Australia to Xinjiang Region were measured. The results showed that the Suffolk sheep and the Polled Dosert sheep were similar or higher than those in Australia in productive rate, and body weight. The comprehensive adaptability of Suffolk sheep and Polled Dosert sheep were 98.80% and 98.74%, respectively. The performance of fattening, slaughtering of F1 of Suffolk and Polled Dosert sheep with Kasak sheep were better than that of Kazak sheep.

Adaptation, Biological↗