Untreated Sheep Research Articles

T and B lymphocyte membrane markers in cells from patients with leukemia and lymphoma.

Rosette formation of human lymphocytes with untreated sheep erythrocytes (E) or sheep erythrocytes treated with antibody and complement (EAC) may be employed as a marker of T and B lymphocytes. Cells from 16 patients with leukemia and from 18 with lymphoma were compared with normal lymphocytes in their ability to form E and EAC rosettes. The results were compared with the <i>in vitro </i>responses to PHA and MLR. A correlation was observed between the impaired responses to PHA and MLR and diminished percentages of cells having receptors for E or both E and EAC.

Effect of gonadotrophins on the production of steroids by sheep ovarian follicles cultured in vitro.

SUMMARY The main objective of the study was to determine the rate at which Graafian follicles of sheep that had been treated with exogenous gonadotrophin acquire the ability to secrete oestrogen in vitro. Follicles were explanted from sheep 5 min to 24 h after injection of pregnant mare serum gonadotrophin (PMSG) and kept individually in culture for 7 days. The mean daily output of oestrogen by follicles from PMSG-treated sheep was higher than that secreted by follicles from untreated sheep. However, only a certain proportion of the follicles from each sheep secreted significant amounts of oestrogen in vitro; these follicles were called 'stimulated'. The proportion of stimulated follicles was 5% for control sheep, 20–30% for follicles explanted from sheep 5 min to 12 h after injection with PMSG, and 80% for follicles explanted from sheep that had been injected with PMSG 24 h previously. In the second part of the study, the pattern of oestrogen and progesterone secretion by stimulated follicles of different sizes explanted from PMSG-treated sheep at various stages of the oestrous cycle was determined. Up to the 14th day, oestrogen production in vitro by follicles over 4·5 mm in diameter reached a maximum 2 days after PMSG injection and decreased thereafter; progesterone production rose steadily as the oestrogen levels declined. In contrast, follicles of less than 4·5 mm diameter secreted considerable amounts of oestrogen for the first 5 days in culture, but produced only small quantities of progesterone. In follicles explanted on day 15, oestrogen secretion decreased steadily from the beginning of the culture period and was very low by the 4th day. Most follicles explanted at oestrus secreted only small amounts of oestrogen in vitro but secreted large amounts of progesterone.

Chemotherapeutic Evaluation of Trimethoprim and Sulphonamides in Experimental Salmonellosis of Sheep

Summary Using an infection method which produced a mortality rate of over 80% in untreated sheep, trimethoprim/sulphonamidc therapy was shown to be effective against Salmonella tlublin in vivo. The marked mutual potentiation of in vitro activity exhibited by the two druos when present together was examined in vivo, and the therapeutic effect of combined treatment was shown to be greatly superior to that of either drug used alone. A 5-day course of treatment was more effective clinically when delayed for 3 or 4 days compared with similar treatment instituted earlier, especially in the prevention of relapses. In comparisons with chloramphenicol used at the same dose rate, trimethoprim/sulphadiazine was shown to possess the same high degree of efficacy.

Trichostrongylosis and wool growth. 2. The wool growth response of infected sheep to parenteral and duodenal cystine and cysteine supplementation

Two experiments are reported. In experiment 1, light infections with the intestinal nematode Trichostrongylus colubriformis reduced wool growth of sheep by 42 per cent compared with pair-fed controls. There was no significant difference in wool growth between those sheep given a cystine supplement as an intraperitoneal pellet and those given a daily intra-duodenal injection of cystine, although cystine was poorly absorbed from the peritoneal cavity. In experiment 2, fifteen sheep were fed a maintenance ration and their wool growth rates defined. When six of the sheep were given a daily intra-duodenal drip containing 2 g cysteine hydrochloride, and six sheep were given the same drip intravenously, their wool growth rate increased by a mean of 33 per cent compared with the wool growth of the three untreated sheep, irrespective of the route of administration of the cysteine. Three sheep in each group of six were then lightly infected with Trichostrongylus colubriformis and the wool production of all sheep was measured in the presence and absence of the daily cysteine supplement via the two routes. The infection depressed wool growth, but did not influence the wool growth response to either route of cysteine supplementation. It was concluded that the reduced wool growth induced by trichostrongylosis could not be attributed to malabsorption of cysteine. Evidence was obtained that sheep resistant to Trichostrongylus colubriformis produced less wool when subjected to a larval challenge.

Trichostrongylid infections of sheep in a winter rainfall region. II. Epizootiological studies in the western district of Victoria, 1967-68

Mean counts of O. circumcincta and Trichostrongylus spp. from groups of 'tracer' sheep ranged between 220 and 2150 per fortnight between June and October and were less than 100 per fortnight from November to February inclusive. O. circumcincta was more numerous than Trichostrongylus spp. The relatively low numbers of available larvae were attributed to the dry weather conditions in autumn which did not favour development and survival of the free-living stages. Between May and December 1967, worm numbers increased linearly in weaner sheep to reach mean levels of 14,000 without any detectable resistance to reinfection or significant decrease in liveweight gain or wool production. Correlations between mean plasma pepsinogen concentrations from weaner and adult sheep and 'tracer' worm burdens were significantly different; r = 0.37 and 0.47 for weaners and r = 0.8 for adult sheep. Thus the relationship between larval intake and abomasal damage as reflected by plasma pepsinogen concentrations is not a simple one. Mucosal damage is probably preceded by a hypersensitive state. Anthelmintic treatment, given in October and January, reduced the worm egg output of treated sheep to one-tenth that of untreated sheep for a period of 18 weeks between October and March.

Effect of the rimino phenazine B663 (G30320) on Mycobacterium johnei infection and reinfection in sheep : I. Bacteriology and hypersensitivity

Experiments in sheep reinfected with M. johnei indicated that an immunity to superinfection had been acquired, in so far as the superinfecting inoculum failed to multiply or cause lesions comparable with those attained in untreated sheep. Treament with rimino phenazine B663 (G30320) orally at the rate of 10 mg. per kg. bodyweight daily for 90 days did not reduce the levels of viable unit counts or the numbers of lesions in treated compared to untreated sheep.

Phagocytosis of erythrocytes by Acanthamoeba sp.

Phagocytic recognition by the unicellular soil organism Acanthamoeba sp. (Neff strain) was examined with fresh or modified erythrocytes. Several parameters were studied of the interaction of glutaraldehyde-treated red cells with amoebae attached to glass. Attachment and ingestion steps of particle uptake were found to have differing temperature dependence. Particle-phagocyte interaction required the addition of Na+ or Ca2+ and was inhibited by high osmolarity or ionic strength. These features are similar to those previously described for mammalian macrophages. A quantitative spectrophotometric technique was adapted to the measurement of erythrocyte uptake after lysis of noningested red cells. Rates of uptake of six species of red cells spanned a 100-fold range. While untreated sheep red cells were taken up at very low rates, ingestion of red cells treated with aldehyde, tannic acid, polylysine, carbodiimide, ferrous sulfate or salt-free sucrose was appreciably increased. Some but not all of these modified red cells were previously found to interact with macrophages and insect hemocytes. Thus Acanthamoeba displays phagocytic recognition of untreated and modified erythrocytes. The results also indicate that the particle vocabulary ingested by the amoebae overlaps in part with that of certain metazoan phagocytes.

Studies on the congenitally goitrous sheep. Iodoproteins of the goitre.

1. Congenitally goitrous thyroid tissue was obtained from South Australian Merino sheep. Ultrastructural studies of the secretory cells in this tissue showed active cells of normal appearance, containing apical protein droplets. 2. (125)I-labelling in vivo of goitre tissue was used to investigate the iodoproteins, in which the major proportion of (125)I appeared in the cell protein fraction soluble in 0.9% sodium chloride (average 62% in goitres from untreated sheep). 3. Ammonium sulphate fractionation showed two clear peaks of iodoprotein precipitation, one at 35-40% saturation and the other at 50-55% saturation. Both iodoprotein fractions contained iodotyrosines and iodothyronines, which were identified chromatographically after enzymic hydrolysis of the protein. 4. Polyacrylamide-gel electrophoresis at pH9.4, at either 7.5 or 5.0% acrylamide concentration, was used to characterize the iodoproteins. Two major fractions were observed, the fastest-migrating fraction coincident with serum albumin, and a slower-migrating, less-well-defined zone. This fraction migrated in 7.5% acrylamide gel, which excluded normal thyroglobulin. 5. Density-gradient (10-40% sucrose) centrifugation was used to determine the approximate sedimentation coefficients of the iodoproteins, which showed major components at s(20,w) 8-9S and s(20,w)<5S. 6. Immunoprecipitation with rabbit anti-(sheep thyroglobulin) failed to sediment (125)I-labelled proteins from goitre extracts. 7. Ouchterlony-type double diffusion in agar plates demonstrated immunoprecipitation lines between rabbit anti-(sheep thyroglobulin) and both the concentrated goitre extract and its Sephadex G-200-excluded fraction, which were confluent with that obtained on reaction with purified normal thyroglobulin. 8. It was concluded that both major iodoprotein fractions were capable of supplying thyroid hormones to the animal, and that the fraction of s(20,w)<5S was iodinated serum albumin. As (125)I-labelled thyroglobulin was not detected in goitre tissue from untreated or thyroxine-treated animals, it was possible that the genetic defect causing goitre resulted in an abnormal thyroglobulin, incapable of being iodinated but immunologically reactive.

Pituitary adrenal interactions in shorn sheep exposed to cold, wet conditions

Newly shorn sheep were exposed to a cold (3°C) wet environment for 8 days; six out of 10 untreated animals died but there were no deaths in a group of 10 that was treated with cortisone. In two other experiments, nine out of 15 control sheep died, but only four out of 15 sheep treated with adrenocorticotrophin (ACTH). In a final experiment approximately one-third of exposed controls died compared with one-tenth of sheep treated with dexamethasone trimethylacetate. A significantly greater proportion (P &lt; 0.05) of sheep given ACTH or 1.5 mg or more of dexamethasone trimethylacetate per kg had rectal temperatures higher than 37.8°C during the first 96 hr of exposure than the comparable controls. The adrenal glands of sheep that died in the cortisone and ACTH experiments were heavier than those taken from survivors that were killed after the experiment; macroscopically, the cortices of some of the adrenals from sheep that succumbed were haemorrhagic and resembled the glands seen in the Waterhouse-Friderichsen syndrome in man; all were heavily infiltrated with lipid when compared with the cortices of survivors. ß-Glucuronidase activity in the serum of cortisone-treated sheep (and in untreated survivors) was elevated during the first 2–3 days of exposure and returned to pre-exposure levels; untreated sheep that succumbed showed continuously increasing enzymatic activity. Acid phosphatase activity was initially depressed in steroid-treated sheep and returned to pre-exposure levels, whereas activity increased continuously in controls that died. Total leucocytes were lower during the first 72 hr of exposure in sheep treated with 1.5–2 mg dexamethasone trimethylacetate per kg, compared with untreated controls. We suggest that the enlarged, fat-laden haemorrhagic adrenals found in sheep that died from cold exposure resulted from excessive ACTH stimulation prior to death. The results suggested a state of adrenocortical insufficiency during the first 96 hr of cold exposure.

Reaction of young adult sheep to vaccination and infection with myxovirus parainfluenza 3

An effect of vaccination against PI 3 virus by measuring the amount of virus excreted in the nasopharynx in vaccinated and in untreated sheep up to 5 days after challenge is described.

Effects of beta-adrenergic blockade on the heart rate and energy expenditure of sheep during feeding and during acute cold exposure.

Heart rates, respiratory exchange, and rectal temperatures of five sheep were measured during 4 h exposure to −30 °C and during a 3-h period at +8 °C in which the sheep fed for 1 h. Propranolol, a beta-adrenergic receptor blocking agent, was infused at 0.25, 0.5, and 1.0 mg/kg in both series of experiments. These doses blocked isoproterenol-induced tachycardia. Exposure of the untreated sheep to −30 °C produced marked increases in both energy expenditure and heart rate. Propranolol infusion at 0.25 and 0.5 mg/kg had no effect on energy expenditure but almost totally abolished cardioacceleration in response to cold. Propranolol at 1.0 mg/kg significantly reduced energy expenditure at −30 °C. Both heart rate and energy expenditure increased markedly in the untreated sheep during feeding. Propranolol at 0.25, 0.5, and 1.0 mg/kg had significantly similar effects on heart rate during feeding, reducing the absolute values attained at only 12%. Cardioacceleration during feeding was, however, reduced by 46% because propranolol infusion increased heart rate in the prefeeding period. Propranolol at 0.5 mg/kg had no effect on energy expenditure during feeding. It was concluded that the sympathetic system, acting through the beta receptors, is of major importance in controlling the metabolic and cardiac responses of sheep to acute cold exposure, but of minor importance in initiating and regulating these responses during feeding.

Detection of Immune Response Against Synthetic Polymers of Amino Acids Employing the Plaque-Forming Cell System

Summary Lymph node tissue from rabbits sensitized with the synthetic terpolymer, G42L28A30, was found to contain antibody-forming cells capable of reacting with GLA-coated erythrocytes in the agar plate method originally devised by Jerne and Nordin. Sheep anti-rabbit globulin completely inhibited the anti-GLA activity in the plaque-forming cells obtained during the early stages following both primary and secondary immunization. Soluble GLA30 (2.4 mg) incorporated into the upper layer also inhibited the response; in contrast, lower concentrations of GLA30 (0.02 mg) had no effect. Passive hemagglutination titers of the sera against GLA-coated sheep cells indicated no correlation between these titers and the magnitude of the plaque-forming cell response in the lymph node tissue, with the possible exception of sera obtained in the early phases following primary immunization. Differences in the reactions against untreated sheep cells and the GLA-coated cells were discussed, including the appearance of the hemolytic zones and the effect of sheep anti-rabbit globulin sera.

Immunological tolerance to microbial antigens. II. Suppressed antibody plaque formation to Shigella antigen by spleen cells from tolerant mice.

Friedman, Herman (Albert Einstein Medical Center, Philadelphia, Pa.). Immunological tolerance to microbial antigens. II. Suppressed antibody plaque formation to Shigella antigen by spleen cells from tolerant mice. J. Bacteriol. 92:820-827. 1966.-An indirect, localized, antibody plaque procedure has been used to demonstrate a marked difference in the number of antibody plaques formed with spleen cell suspensions from normal and Shigella-tolerant mice. Whereas challenge with soluble Shigella antigen (SSA) into normal mice, ranging in age from 4 to 40 weeks, resulted in a rapid rise in antibody plaque formation to Shigella-treated sheep erythrocytes, there was only a slight increase in plaque formation with spleen cell suspensions from similarly challenged mice which had been made tolerant to Shigella antigen during neonatal life. Apparently, the suppression of plaque formation to Shigella in tolerant animals was specific, since both Shigella-tolerant and normal mice responded equally well to untreated sheep red blood cells after challenge with sheep erythrocytes only. Spleen cells from nonchallenged Shigella-tolerant mice did not form significant numbers of antibody plaques to SSA-treated red blood cells during an observation period of 4 to 30 weeks after neonatal administration of antigen. "Nonspecific" increases in plaque formation to untreated sheep red cells occurred with spleen cell suspensions from both normal and SSA-tolerant mice after challenge injection with Shigella antigen, with or without sheep erythrocytes. Such a response suggested an adjuvant effect for the endotoxin-containing Shigella antigen even in mice tolerant to the agglutinogenic moiety of SSA. The results of these experiments support the view that specific antibody-forming cells are either absent or in low number in lymphoid tissue from mice specifically tolerant to Shigella antigens. It seems unlikely that the low postchallenge agglutinin titers of tolerant mice are due to suppressed antibody formation by normal numbers of individual antibody-producing cells, or due to "masking" of normal antibody production by persisting circulating antigen.

Observations on the thrift of young sheep on a marginally Cobalt-Deficient area

Abstract Weight changes of cobalt-dosed and untreated sheep were compared in seven trials, carried out over a seven-year period at the Wallaceville Animal Research Centre, on land consisting mainly of stonier phases of Heretaunga-Gollans silt loam soils. Significant weight responses of sheep as lambs were obtained in four out of seven trials (in 1952, 1953, 1954, and 1957, but not in 1951, 1955, and 1956). Sheep responded as two-tooths in two trials but not in another. In the one trial in which it was used, there was a small though significant response to hexoestrol, but no interaction between the effects of hexoestrol and cobalt treatments. In some years there was considerable unthriftiness and mortality among lambs, irrespective of cobalt treatment. It is considered that a number of factors other than cobalt deficiency, notably internal parasitism, contributed greatly to the unthriftiness and mortality experienced. It was noted that for the years 1953 to 1957 inclusively, during autumn, cobalt-treated lambs at Winton in Southland grew much better than did cobalt-treated lambs at Wallaceville. The years in which lamb growth was poorest were also the years in which no responses to cobalt occurred. The concept of marginal cobalt deficiency is described. Results of analyses of soils, pastures, and livers for cobalt, and of livers for vitamin B12, are given, and limitations of the diagnostic value of analytical data, with particular reference to marginal deficiency, are discussed. An important aspect of the present work is considered to be the focusing of attention on the possibility of marginal cobalt deficiency affecting young sheep, over extensive areas of light stony soils related to Heretaunga silt loam, notably in Wairarapa and Canterbury.

The effect of thyroxine on the mean and variance of wool production of Merino sheep on natural pasture

Administration of sodium-1-thyroxine to 14-15 months old medium Peppin Merino wethers resulted in a significant increase in both greasy and clean wool production (P&lt;0.05 in each case) when the wethers were grazing on natural pasture in south-western Queensland. This was demonstrated in an analysis of wool production during a total period of 24 months. Within this period, the wethers treated with thyroxine produced seven per cent more greasy wool per head than did the untreated control sheep (P&lt;0.01) and seven per cent more clean wool (P&lt;0.05) during the 15 weeks following implantation. During the subsequent 17 weeks the treated wethers produced three per cent more greasy wool than the controls (P&lt;0.05), but there was no significant difference in clean wool production. There were no significant differences in either greasy or clean wool production in either of the last two periods of the 24-month experiment. There were no significant differences in wool production among the three groups of wethers whose dose rates at a single implantation were 30 mg, 60 mg, and 90 mg respectively. Administration of thyroxine resulted in a significant increase in the variance of greasy wool production during the 15 weeks following implantation (P&lt;0.05) hut had no effect on the variance of clean wool production. The rate of gain in body weight displayed by all groups that received thyroxine was retarded, but groups had returned to their pre-treatment body weight ranking five months after implantation. Mortality was one per cent per annum among implanted animals over the two years following implantation. It is suggested that the response to thyroxine administered in mid-summer may have resulted partly from making good a seasonal deficiency in thyroid secretion. The tactical use of thyroxine to increase wool production per head in a region of considerable within-year or between-year variation of rainfall characterized by unpredictable flushes of pasture growth is discussed. The limited influence of thyroxine on the variance of wool production does not encourage its use as an aid to selection for clean wool production per head.

Louse control in sheep—a comparison of seven dipping preparations

Abstract Plunge-dipping was carried out using an arsenical dip (sodium arsenite) and six organo-phosphorus compounds (diazinon, “Bayer S 1752,” “Lucijet,” “Asuntol,” “Nankor,” and “Delnav”). A complete kill of body lice (Damalinia avis) was recorded with all dips. Dipped sheep were run with untreated louse-infested sheep, and periods of two to five months' freedom from louse re-infestation were recorded.

Stimulation of wool growth by thyroxine implantation. II. Feed intake of grazing Merino wethers treated repeatedly with thyroxine.

Estimates have been made of the feed intake of wethers that received implantations of 60 mg thyroxine every 3 months, and of untreated sheep, grazing together. The estimated intake of digestible organic matter (D.O.M.) by treated wethers was higher than that of controls in 24 out of 27 measurement periods. The difference in feed intake was least in the iirst month after implantation, when the treated sheep lost weight, and greatest in the second and third months when the treated sheep were regaining weight. The overall increase in intake resulting from thyroxine treatment (20–25%) was greater than the increase in wool production (7% greasy weight, 3-7 % clean weight), and the efficiency of wool production was therefore lower in thyroxinetreated wethers. From the relationships between feed intake and rate of weight change it was concluded that in the month after implantation, when pulse rates indicated a substantial rise in metabolic rate, the maintenance feed requirement was raised from about 560 g to about 780 g D.O.M. per day. Observations in two winters with recently shorn sheep gave estimates of maintenance requirements for untreated wethers ranging from 850 to 1300 g D.O.M. per day. During recovery from repeated thyroxine implantation the wethers gained in weight no more efficiently than the controls. The mechanism of action of exogenous thyroxine is discussed in the light of these and other data.

Carbon tetrachloride poisoning in sheep: Effect upon the serum E260 value and plasma volume

Serum E260 values were determined at intervals in sheep which were given 50 ml carbon tetrachloride (CCl4) by stomach tube into the rumen, and in untreated sheep. After administration of the drug, the mean E260 value fell initially, being minimal at 3 hr. At this time, the circulating plasma volume had increased by one-fifth, and it is considered that this dilution factor largely explained the fall. The group mean for non-fatal cases rose above the pre-administration level at 7 hr, then returned to it by 24 hr. However, in the one sheep that died from CCl4 poisoning, the serum E260 value remained very high until death at 46 hr. In view of the significant variations in serum E260 values between untreated sheep, and the significant random variations in serum E260 values between times of bleeding such sheep, it is concluded that the determination of serum E260 values at isolated times in individual sheep is of no value as a diagnostic criterion of CCl4 poisoning.

Sheep Ked Control in Oregon Farm Flocks

A high level of sheep ked control in western Oregon farm flocks resulted from applications of 1.5 % dieldrin dust at rates of about 2 ounces per head by means of a hand operated rotary duster. Post-treatment re-infestation due to mingling of treated and untreated flocks was found to materially reduce the effectiveness of the treatment, while the effect of either three or six untreated sheep on the quality of ked control in a flock was less apparent. Little difference could be detected in the effects of applications made during each of three portions of the yearly flock management cycle. Under western Oregon management conditions, treatments after the last fat lamb has been selected from the flock in the fall and before the Hock or the remaining lambs go on winter feed, are thought most likely to result in minimum residues in slaughter lambs.