Ovine atrial natriuretic factor: sequence of circulating forms and metabolism in plasma.

The sequence of ovine ANF is not known, yet sheep have been used extensively for ANF studies. We sequenced the circulating form of ovine ANF from coronary sinus plasma of sheep in paced heart failure. The main circulating form was identical to human ANF(99-126). Small amounts of ANF identical to human ANF(103-126) and ANF(101-126) peptides were also found. Incubation of labeled ANF in ovine serum suggested ANF(103-126) could be a degradation product of ANF(99-126). The endopeptidase-24.11 degradation product ANF(99-105/106-126) was not found in ovine plasma, in contrast to human plasma where it was a minor component. These results show that while the main circulating forms are similar in sheep and humans, there are differences in the minor peptides.     

Comparison of Gene Expression by Sheep and Human Blood Stimulated with the TLR4 Agonists Lipopolysaccharide and Monophosphoryl Lipid A

Background

Animal models that mimic human biology are important for successful translation of basic science discoveries into the clinical practice. Recent studies in rodents have demonstrated the efficacy of TLR4 agonists as immunomodulators in models of infection. However, rodent models have been criticized for not mimicking important characteristics of the human immune response to microbial products. The goal of this study was to compare genomic responses of human and sheep blood to the TLR4 agonists lipopolysaccharide (LPS) and monophosphoryl lipid A (MPLA).

Methods

Venous blood, withdrawn from six healthy human adult volunteers (~ 28 years old) and six healthy adult female sheep (~3 years old), was mixed with 30 μL of PBS, LPS (1μg/mL) or MPLA (10μg/mL) and incubated at room temperature for 90 minutes on a rolling rocker. After incubation, 2.5 mL of blood was transferred to Paxgene Blood RNA tubes. Gene expression analysis was performed using an Agilent Bioanalyzer with the RNA6000 Nano Lab Chip. Agilent gene expression microarrays were scanned with a G2565 Microarray Scanner. Differentially expressed genes were identified.

Results

11,431 human and 4,992 sheep probes were detected above background. Among them 1,029 human and 175 sheep genes were differentially expressed at a stringency of 1.5-fold change (p<0.05). Of the 175 sheep genes, 54 had a known human orthologue. Among those genes, 22 had > 1.5-fold changes in human samples. Genes of major inflammatory mediators, such as IL-1, IL-6 and IL-8, TNF alpha, NF-kappaB, ETS2, PTGS2, PTX3, CXCL16, KYNU, and CLEC4E were similarly (>2-fold) upregulated by LPS and MPLA in both species.

Conclusion

The genomic responses of peripheral blood to LPS and MPLA in sheep are quite similar to those observed in humans, supporting the use of the ovine model for translational studies that mimic human inflammatory diseases and the study of TLR-based immunomodulators.     

Radionuclide concentration ratios in Australian terrestrial wildlife and livestock: data compilation and analysis

Radionuclide concentrations in Australian terrestrial fauna, including indigenous kangaroos and lizards, as well as introduced sheep and water buffalo, are of interest when considering doses to human receptors and doses to the biota itself. Here, concentration ratio (CR) values for a variety of endemic and introduced Australian animals with a focus on wildlife and livestock inhabiting open rangeland are derived and reported. The CR values are based on U- and Th-series concentration data obtained from previous studies at mining sites and ²⁴¹Am and ^239/240Pu data from a former weapons testing site. Soil-to-muscle CR values of key natural-series radionuclides for grazing Australian kangaroo and sheep are one to two orders of magnitude higher than those of grazing cattle in North and South America, and for ²¹⁰Po, ²³⁰Th, and ²³⁸U are one to two orders of magnitude higher than the ERICA tool reference values. When comparing paired kangaroo and sheep CR values, results are linearly correlated (r = 0.81) for all tissue types. However, kidney and liver CR values for kangaroo are typically higher than those of sheep, particularly for ²¹⁰Pb, and ²¹⁰Po, with values in kangaroo liver more than an order of magnitude higher than those in sheep liver. Concentration ratios for organs are typically higher than those for muscle including those for ²⁴¹Am and ^239/240Pu in cooked kangaroo and rabbit samples. This study provides CR values for Australian terrestrial wildlife and livestock and suggests higher accumulation rates for select radionuclides in semi-arid Australian conditions compared with those associated with temperate conditions.     

Population structure, genetic variation and morphological diversity in indigenous sheep of Ethiopia

We investigated genetic and morphological diversity and population structure of 14 traditional sheep populations originating from four ecological zones in Ethiopia (sub-alpine, wet highland, sub-humid lowland and arid lowland). All animals (n = 672) were genotyped for 17 microsatellite markers and scored for 12 morphological characters. The sheep were initially classified as fat-tailed (11 populations), thin-tailed (one population) and fat-rumped sheep (two populations). These classifications are thought to correspond to three consecutive introduction events of sheep from the Near-East into East Africa. For the 14 populations, allelic richness ranged from 5.87 to 7.51 and expected heterozygosity (H(E)) from 0.66 to 0.75. Genetic differentiations (F(ST) values) between all pairs of populations, except between sub-alpine populations, were significantly different from zero (P < 0.001). Cluster analysis of morphological characters and a dendrogram constructed from genetic distances were broadly consistent with the classification into fat-tailed, thin-tailed and fat-rumped sheep. Bayesian cluster analysis using microsatellite markers indicated that there has been further genetic differentiation after the initial introduction of sheep into Ethiopia. Investigation of factors associated with genetic variation showed that an isolation-by-distance model, independently of other factors, explained most of the observed genetic variation. We also obtained a strong indication of adaptive divergence in morphological characters, patterns of morphological variation being highly associated with ecology even when the effect of neutral genetic divergence (F(ST)) was parcelled out in partial Mantel tests. Using a combination of F(ST) values, Bayesian clustering analysis and morphological divergence, we propose a classification of Ethiopian sheep into six breed groups and nine breeds.     

A survey of Clostridium perfringens enterotoxin antibody in human and animal sera in western Canada

Sera from human, cattle, sheep, swine, and horse populations in western Canada were tested for the presence of Clostridium perfringens enterotoxin antibody by the passive hemagglutination (PHA) test, supplemented by an immunodiffusion test and by counterimmunoelectrophoresis. A total of 224 human, 345 cattle, 165 sheep, 620 swine, and 768 horse serum samples were examined. Low-titer reactions in the PHA test were detected in human, cattle, horse, and swine sera, in that order, with no titers demonstrated in sheep. The titers in human sera ranged up to 1:128 and three of these samples were also positive in the other two serological tests. The significance of this antibody is not clear, but it is suggested that the low prevalence of the antibody may reflect a low prevalence of enterotoxigenic C. perfringens strains in western Canada. Such serological surveys may be applicable to epidemiological studies involving enterotoxigenic C perfringens.     

Fluorescent in-situ hybridization of cattle and sheep chromosomes with cloned human fragile-X DNA

An extensive study on spontaneous and 5-Fluorodeoxyuridine induced fragile sites identified Xq31 in cattle (Bos taurus) and (Xq24, Xq26) in sheep (Ovis aries) in addition to several autosomal fragile sites (under publication). A ZOO-FISH study using three cloned human fragile-X probes with CCG/CGG_n trinucleotide repeat sequence was carried out to determine homology between human and bovine fragile-X. The hybridisation results showed only a weak signal on a human chromosome that was not an X with all three fragile site probes. No signals were detected in sheep chromosomes. The signal of all three human fragile-X probes on cattle chromosomes was however, medium-prominent sub-centromeric signal on two homologues. BrdU administration in 12 h before harvesting identified these homologues to be chromosome number 5. In addition retrospective slides of cattle and sheep chromosomes used for fragile site studies showed no signals whatsoever. It was therefore concluded that no homology existed between human and bovine fragile-X.     

Genetic and phenotypic parameters of body weight in West African Dwarf goat and Djallonké sheep

The International Trypanotolerance Centre's small ruminant breeding programme was initiated in 1995. The aim was to increase the efficiency of meat production and the trypanotolerance of the animals (sheep and goat). To achieve that goal, selection was based on estimated breeding values for daily weight gain from 4 to 12 months of age measured on trypanotolerance challenge. The purpose of this study was to estimate genetic parameters for growth traits and to evaluate genetic trends in West African Dwarf goat and Djallonké sheep resulting from the breeding programme under a low input production environment. Data for West African Dwarf goat and Djallonké sheep included birth weight (BW), weaning weight (W120), yearling weight (W360), pre-weaning (GR0–4) and post-weaning (GR4–12) growth rate. The data were analysed using an animal model that accounted for fixed effects of sex, year of birth, season of birth, parity of the dam, type of birth and the interaction year by season of birth. Estimates of heritability for BW, W120, W360, GR0–4 and GR4–12 were 0.5, 0.43, 0.30, 0.32 and 0.11 for goats and 0.39, 0.54, 0.21, 0.54 and 0.23 for sheep, respectively. The genetic correlation between BW and W120 was high for goats (0.74) and moderate for sheep (0.47). Genetic correlations between W120 and GR4–12 were high (0.92) for goats and moderate (0.49) for sheep. Between GR0–4 and BW the correlation was positive but low for sheep (0.26) and moderate for goats (0.60). Positive trends were found in mean estimated breeding values for animals born in the period 1995–2002 which demonstrated the effectiveness of the implemented breeding programs.     

Zero-stress state of intra- and extraparenchymal airways from human, pig, rabbit, and sheep lung.

Alterations in airway wall anatomic properties and the consequential effects on airway narrowing have been assessed by use of computational models. In these models, it is generally assumed that at zero transmural pressure the airway wall exists in a zero-stress state. Many studies have shown that this is often not the case, as evidenced by a nonzero opening angle. In this study, we measured the opening angle of airway rings at zero transmural pressure to test this assumption. The airway tree was dissected from human, pig, sheep, and rabbit lungs. Airways were excised from the tree, and the opening angle was measured. There were obvious species and regional differences in opening angle. Rabbit airways from both extraparenchymal and intraparenchymal sites exhibited marked opening angles (7-82 degrees). Extraparenchymal airways from sheep had large opening angles (up to 50 degrees), but ovine intraparenchymal airways had small opening angles. Measurable opening angles were rarely observed in human and porcine airways of any size. The assumption of a stable zero-stress state at zero transmural pressure is therefore valid for human and porcine, but not rabbit and sheep, airways.     

Hematology and serum biochemistry of European mouflon (<Emphasis Type="Italic">Ovis orientalis musimon</Emphasis>) in Croatia

The aim of the present study was to determine the reference intervals for the most commonly used hematological and biochemical parameters of European mouflon from a closed hunting ground in the eastern part of the Republic of Croatia. Blood samples were collected from 39 live, physically restrained, clinically normal European mouflon, as well as from 50 domestic sheep. The distribution of values within each parameter was determined and statistical differences in values between sexes were also determined. For each sample, 14 hematological and 18 biochemical parameters were analyzed. Hematology and biochemistry values of the European mouflon were also compared with the values of domestic sheep. In further studies, the established values might be useful for the health assessment of mouflon.     

Membrane orientation of sheep spectrin

Based primarily on studies of human erythrocytes, current theories of the structure and organization of erythrocyte membrane localize spectrin to the membrane cytoplasmic surface. Affinity purified anti-sheep spectrin antibodies were used in indirect immunofluorescence studies of intact erythrocytes from various vertebrate species and inside-out and right-side-out impermeable sheep erythrocyte vesicles. This investigation detected immunologically reactive external and potentially transmembranal determinant(s) of the sheep erythrocyte spectrin "assembly." Parallel studies using anti-sheep and anti-human spectrin antibodies, as well as 125I surface-labelling studies of intact sheep and human erythrocytes, indicated that this particular membrane orientation of spectrin was evident in sheep but not in human erythrocytes. Antisera containing antibodies to the external portion of this spectrin "assembly" demonstrated external fluorescence to a variable degree on some, but not all, vertebrate erythrocytes surveyed, confirming that the sheep erythrocyte was not the only exception. It is suggested that there may be subtle species variability in the intermolecular associations of the spectrin "assembly" with(in) the erythrocyte membrane not requiring alterations of the spectrin molecule itself.     

Purification, properties and kinetics of sheep and human renin substrates.

Sheep plasma renin substrate was purified 1,200-fold by using nephrectomised sheep plasma, followed by DEAE-Sephadex chromatography and gel filtration. The purified substrate contained 8 mu-g angiotensin II/mg protein and had an estimated molecular weight of 52,000. The kinetic characteristics of the purified substrate were identical both to those of unpurified nephrectomised sheep plasma and to normal sheep plasma substrates. At pH 7.5, K-m of the human renin-sheep substrate reaction was 0.29 mu-M and for sheep renin-sheep substrate, 2.0 mu-M. Sheep substrate was susceptible to peptic digestion with generation of pepsitensin. Human renin substrate was less readily purified. DEAE-Sephadex chromatography of plasma from pregnant women at 36-40 weeks' gestation produced a 70-fold increase in purity (0.9 mu-g angiotensin II/mg protein). No further increase was achieved with gel filtration. Human renin substrate behaved as a larger (mol. wt. 82,000) more anionic protein than sheep substrate and was resistant to the proteolytic actions of both pepsin and sheep renin. K-m for the human renin-human substrate reaction was high and could not be accurately determined (range 3-8 mu-M, mean 5.7 mu-M). The presence of human substrate in a human renin-sheep substrate system did not alter the measured initial velocity. In both sheep and man, the normal concentration of renin substrate is considerably less than K-m and must therefore be considered a determinant of angiotensin production rate in vivo.     

Cardiopulmonary reference standards in the pregnant sheep (Ovis aries): a comparative study of ovine and human physiology in obstetrics.

1. Complete blood counts, respiratory rate, tidal volume, arterial and mixed venous blood gases; heart rate, cardiac output, and arterial, pulmonary artery, central venous and pulmonary wedge pressures were determined in 10 pregnant adult sheep of 42.7-65.7 kg body weight. 2. Arithmetic means, standard deviations, and coefficients of variation were calculated to develop reference values; in addition, the 95% confidence limits for ranges were established. 3. Comparison of derived data with that from non-pregnant sheep shows changes similar to those seen when examining pregnant and non-pregnant humans. 4. These results indicate the pregnant sheep is an acceptable model for human obstetrical research.     

Basic haematological values in antelopes--IV. A comparison and concluding remarks

Comparison of mean erythrocyte counts, mean haematocrit values, mean haemoglobin content and mean corpuscular volume of the red cell is presented for 21 species of antelopes (four species being excluded because of the small number of animals investigated). A direct relationship of haematocrit values and haemoglobin content and an inverse relationship of red cell counts and mean corpuscular volume of the erythrocytes were noted. The significance of an increased total surface area for oxygen exchange is discussed and values obtained in the red blood picture are compared with those of domesticated animals (cattle, goat and sheep) taken from the literature. Mean leukocyte counts were found to be in the human range with the exception of two species, but significantly lower than in domesticated artiodactylids. Problems in assessing the general health, the age, the effect of diet and of environment in captivity are discussed. Problems of methodology, especially of blood sampling, are given comparing results in manually restrained and in sedated animals.     

Immunochemistry of serum albumin. VI. A dynamic approach to the immunochemical cross reactions of proteins using serum albumins from various species as models.

Antisera against bovine serum albumin were raised in two rabbits. Serial bleedings were obtained at different times after the first immunization, and antisera from these serial bleedings were not mixed but were kept and studied separately. The immunochemical cross-reactions of these antisera with serum albumins from bovine, goat, sheep, porcine, horse, human and chicken were determined by immunoadsorbent studies. These were done by titration so that the values of maximum (plateau) binding by each albumin of radioiodinated antibodies were determined. In each rabbit, the immunochemical cross-reactivity was not static but increased progressievly with time after the first immunization. In the interval 7 days to 398 days the increases in cross-reaction were extremely large. pH dissociation studies revealed that, together with the increase in cross-reactivity of a given albumin with time after immunization, there was a restriction in the antibody heterogeneity towards populations possessing higher affinity. These results provide a rational explanation for the different values of cross-reactivities for a given albumin from different laboratories. The findings are analyzed in relation to the antigenic structure of albumin and their significance in evolutionary studies discussed.     

Effect of sheep and human follicular fluid on the maturation of sheep oocytes in vitro

This study examines the effect of sheep and human follicular fluid on the in vitro maturation (IVM) of sheep follicular oocytes. Oocyte cumulus complexes recovered post mortem were matured for 24 to 26 h at 38.6 degrees C, 5% CO(2) in air, in TCM-199 bicarbonate medium supplemented with 20% fetal calf serum (FCS) and, where stated, with maturation hormones, including FSH (5.0 ug/ml), LH (5.0 ug/ml) and estradiol (1 ug/ml), or with sheep follicular fluid recovered from large (>5mm) or small (2 to 5mm) ovarian follicles post mortem, or with human periovular follicular fluid obtained during routine IVF procedures. The matured oocytes were then denuded, and their maturation stage and developmental capacity were assessed by in vitro fertilization (IVF) and culture (IVC). It was found that inclusion of sheep or human follicular fluid or hormone supplements in the IVM media more than doubled the number of oocytes completing maturation (FCS alone 33%, compared with 76.2% for maturation hormones, 84.2% for fluid from large and 69.6% for fluid from small sheep follicles and 82.6% for human follicular fluid), and significantly increased fertilization rates (FCS alone 51.6%, compared with 71.9% for maturation hormones, 78.4% for fluid from the large and 75.7% for fluid from small sheep follicles and 73.1% for human follicular fluid) without discernible adverse effects on the development of the cleaving embryos to the morula or blastocyst stage in culture. Omission of FCS and supplements from the IVM medium resulted in a marked reduction (56%) in the number of oocytes maturing. This reduction could be offset to a large part, but not completely, by inclusion of human follicular fluid or human follicular fluid plus LH (5 ug/ml) in the medium. The results of this study show that addition of sheep or human follicular fluid to maturation medium can enhance rather than inhibit the maturation and fertilizability of sheep follicular oocytes in vitro.     

Hair Sheep Blood,Citrated or Defibrinated,Fulfills All Requirements of Blood Agar for Diagnostic Microbiology Laboratory Tests

Background

Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis [1], [2]. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies.

Methods and Findings

Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test.

Conclusions

The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to dramatically improve the safety and accuracy of laboratory diagnosis of pathogenic bacteria in resource-poor countries.     

Plasmalemmal H+ extruders in mammalian alveolar macrophages

The distribution of plasmalemmal V-type H+-pumps (V-ATPase) among mammalian macrophages (mvarphi) is uncertain and, hence, the functional significance of mvarphi plasmalemmal V-ATPase is unclear. This study investigated the role of V-ATPase in the regulation of intracellular pH (pH(i)) by resident alveolar mvarphi from sheep, pigs, dogs and rabbits. The fluorescent probe 2',7'-biscarboxyethyl-5,6-carboxyfluorescein was used to monitor baseline pH(i) and the rate of pH(i) recovery (dpH(i)/dt) from intracellular acid-loads (NH(4)Cl prepulse). Baseline pH(i) was 7.1-7.2. In sheep, pig and dog studies, 10 microM bafilomycin A(1) (a selective V-ATPase inhibitor) caused a rapid fall in baseline pH(i) (0.15-0.20 units); baseline values were unaffected by 0.1 mM amiloride (a Na+ transport inhibitor). V-ATPase activity (bafilomycin-sensitive component of dpH(i)/dt) was solely responsible for pH(i) recovery from intracellular acid-loads at acid-loaded pH(i) values >6.8-6.9. Na+/H+ exchange (amiloride-sensitive component of dpH(i)/dt) was detected only at acid-loaded pH(i) values <6.8. The activity of both H+ extruders increased at lower pH(i) values, albeit the Na+/H+ exchanger was more pH-sensitive than was V-ATPase. In rabbit studies, 10 microM bafilomycin A(1) and 1 mM N-ethylmaleimide (a non-specific H+-pump inhibitor) produced similar falls in baseline mvarphi pH(i), but had significantly larger effects than did the selective V-ATPase inhibitor concanamycin A (相似文献   

Thrombin-induced chemotaxis and aggregation of neutrophils

Thrombin-induced neutrophil chemotaxis and aggregation were studied using cells isolated from either human or sheep blood. Sheep neutrophils (10(8) cells/ml) exhibited maximum chemotactic migration towards 10(-8)M human alpha-thrombin, 10(-8)M gamma-thrombin (which lacks the fibrinogen site), and 10(-12)MD-Phe-Pro-Arg-CH2-alpha-thrombin (catalytically inactive thrombin). Chemotactic responses of the same magnitude were obtained with human neutrophils (10(8) cells/ml). The chemotactic responses to thrombin were comparable to those obtained with diluted (1:200 v/v) zymosan activated serum (ZAS) and 10(-11)M FMLP. Premixing of the thrombin forms with hirudin in 1:1 stoichiometric amounts abolished the chemotaxis but not chemokinesis Aggregatory responses of human and sheep neutrophils were comparable for ZAS, alpha-thrombin, and gamma-thrombin. The responses of both human and sheep neutrophils to D-Phe-Pro-Arg-CH2-alpha-thrombin were attenuated, indicating that the proteolytic site may be involved in the aggregatory response. The results suggest that thrombin-induced neutrophil chemotaxis and aggregation are mediated by different mechanisms, since chemotaxis is a catalytically independent response whereas aggregation is an active site independent response.     

Sheep linkage mapping: restriction fragment length polymorphism detection with heterologous cDNA probes

Summary. A selection of cattle, human and sheep cDNA probes were screened against sheep genomic DNA, cut with 10 different restriction enzymes, to assess the usefulness of these probes for restriction fragment length polymorphism (RFLP) linkage studies in sheep. Two-thirds of the cattle cDNA probes showed moderate to strong homology with sheep DNA samples, compared with less than half of the human cDNA probes at the final washing stringency chosen for the experiments. The set of probes tested detected a useful frequency of RFLPs. Fifty-seven per cent of probes showing moderate to strong homology identified RFLPs with one or more restriction enzymes. Restriction enzymes that detected RFLPs most frequently in sheep were Taq I and Msp I. The results show that sheep and cattle cDNA probes, including candidate genes for production traits, identified a high frequency of RFLPs suitable for genetic mapping in sheep.