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Mitochondrial DNA genotypes in nuclear transfer-derived cloned sheep.

Eukaryotic cells contain two distinct genomes. One is located in the nucleus (nDNA) and is transmitted in a mendelian fashion, whereas the o … imal cloned from an established adult somatic cell line, and in nine other nuclear transfer-derived sheep generated from fetal cells. The mtDNA of each of the ten nuclear-transfer sheep was derived exclusively from recipient enucleated oocytes, with no detectable contribution from the respective somatic donor cells. Thus, although these ten sheep are au …

Propranolol blocks cocaine-induced cerebral vasodilation in newborn sheep.

OBJECTIVE: The objective of this study was to test the hypothesis that cocaine-induced cerebral vasodilation in newborn sheep is mediated via beta-adrenergic receptor activation. DESIGN: The cerebral effects of a single intravenous injection of cocaine (4 mg/kg) given 30 mins after pretreatment with propranolol (1 mg/kg) were studied and compared with the results from a previous study using an identical cocaine protocol without propranolol pretreatment. SUBJECTS: Seven chronically catheterized, unanesthetized newborn sheep (6 +/- 1 days old). MEASUREMENTS: Cerebral blood flow using radiolab…

Dialysis access failure: A sheep model of rapid stenosis.

PURPOSE: Intimal hyperplasia at the venous anastomosis of dialysis access grafts causes early failure, although increased flow inhibits intimal hyperplasia in arterial grafts and after vessel injury. We designed a sheep model to study this process. METHODS: Polytetrafluoroethylene (PTFE) grafts were placed in the necks of sheep from the carotid artery to the external jugular vein. Grafts were harvested after perfusion fixation at 4, 8, and 12 weeks and submitted for histologic and immunohistochemical examination, including morphometry of neointimal lesions. RESULTS: The venous anastomoses de…

Thermal drive contributes to hyperventilation during exercise in sheep.

The etiology of exercise hypocapnia is unknown. The contributions of exercise intensity (ExInt), lactic acid, environmental temperature, rectal temperature (Tre), and physical conditioning to the variance in arterial CO2 tension (PaCO2) in the exercising sheep were quantified. We hypothesized that thermal drive contributes to hyperventilation. Four unshorn sheep were exercised at approximately 30, 50, and 70% of maximal O2 consumption for 30 min, or until exhaustion, both before and after 5 wk of physical conditioning. In addition, two of the sheep were shorn and exercised at each intensity in…

Pasteurella haemolytica complicated respiratory infections in sheep and goats.

Respiratory infections which commonly occur in sheep and goats often result from adverse physical and physiological stress combined with viral and bacterial infections. Inevitably, Pasteurella haemolytica pneumonia occurs as a result of these interactions. In this review, we present recent advances in research on the complex etiology of pneumonia involving P. haemolytica. Initially stress, induced by factors such as heat, overcrowding, exposure to inclement weather, poor ventilation, handling and transport is a major predisposing factor. Respiratory viruses including parainfluenza 3 (PI-3) vir…

Fasciola hepatica infection in sheep: changes in liver metabolism.

Several aspects of liver function during infection with Fasciola hepatica were examined in sheep four weeks after infection and compared with the changes observed in infected rats. Previously reported respiratory abnormalities in mitochondria isolated from the left lobe of the liver of infected sheep were characterised further. Evidence is presented that the respiratory lesion is located in the mitochondrial electron transport chain and that the aberrant respiratory behaviour is not associated with an increase in nonesterified fatty acids and the depletion of mitochondrial phospholipids, as is…

Immunisation regimes used to elevate serum IgE in sheep.

Six different immunisation regimes were used in an attempt to elevate the concentration of ovine IgE. The response was measured by a passive cutaneous anaphylaxis (PCA) test. These regimes included infection with Ascaris suum and the combination of infection and parenteral administration of Ascaris antigens and ovalbumin in adjuvants. The regime producing the highest titre of IgE was the combination of Ascaris infection with parenteral administration of Ascaris extract in Bordetella pertussis. This regime consistently produced a transient high titre (1:1280-1:2560) of serum IgE 9-12 days after

Toxicity of Compound 1080 livestock protection collars to sheep.

The toxicity of Compound 1080 (sodium fluoroacetate) livestock protection collars (LPCs) to sheep was investigated. Lambs wearing punctured LPCs were observed to determine dermal toxicity, sheep were fed hay treated with LPC solution to find a lethal concentration, hay treated with a lethal concentration was subjected to sun and simulated rain to assess weathering influences, and sheep were held on pasture treated with LPC solution to evaluate grazing effects. Five lambs that wore punctured LPCs for up to seven days showed no dermal erythema or edema, but three died after ingesting 1080 from L…

Long-term evaluation of prosthetic mitral valves in sheep.

We have developed an in vivo model for chronic evaluation of prosthetic heart valves using juvenile domestic sheep. This report summarizes the results of a study conducted to assess a new bileaflet prosthetic valve. Nine juvenile sheep underwent mitral valve replacement using standard cardiopulmonary bypass techniques including mild hemodilution, systemic hypothermia, and cold fibrillatory arrest. The average time on cardiopulmonary bypass was 57 min. There were no surgical or anesthetic complications. Two (22%) early deaths occurred due to prosthetic annular size disproportion (1) and preexis…

Epidemiology of sheep myiases in São Paulo State, Brazil.

A survey of Diptera species causing cutaneous myiases on sheep in Botucatu, São Paulo, Brazil was made to determine seasonal incidence, predilection sites and the factors predisposing to infestation. Sheep were checked daily for myiases for one year. At two week intervals larvae from wounds were collected for identification. Only larvae of Dermatobia hominis and Cochliomyia hominivorax were found. Myiases due to C. hominivorax were observed during the whole year with high incidence from January to April. The feet, vulva, tail and scrotum were most frequently infested. Wounds were the commonest…

Toxicosis in sheep following ingestion of natural gas condensate.

Thirty of 200 ewes died or were euthanatized during a 21-day period following a 1-day accidental exposure to natural gas condensate, a compl … uents. This appears to be the first reported incidence of natural gas condensate toxicity involving sheep or other ruminants. Although the available literature presents a suggestive pattern of clinical signs and pathologic lesions of petroleum product poisoning, diagnostic investigations should employ detailed analytic examination because each source of …

Cardiovascular responses to hypoxemia in sinoaortic-denervated fetal sheep.

Fetal cardiovascular response to acute hypoxemia is characterized by bradycardia, hypertension, and redistribution of cardiac output. The role of aortic and carotid chemoreceptors in mediating these responses was examined in eight sinoaortic-denervated and nine shamoperated fetal lambs. Blood gases, pH, heart rate, arterial pressure, and blood flow distribution were determined before and during hypoxemia. In intact fetuses, heart rate fell from 184 +/- 12 to 165 +/- 23 beats/min (p less than 0.01) but increased from 184 +/- 22 to 200 +/- 16 beats/min (p less than 0.05) in the sinoaortic-denerv

Histopathological changes in sheep experimentally infected with Babesia ovis.

Histopathological study was made of 12 Merino sheep - five splenectomized and seven intact - experimentally infected with Babesia ovis. Non-purulent encephalitis; initially exudative and subsequently interstitial pneumonia; pericarditis, myocarditis and haemorrhagic endocarditis; centrilobular necrotic hepatitis; hyperplasia of the lymphoreticular system; necrosis and vascular changes in adrenal glands were observed. The kidney was the most severely affected organ, exhibiting acute tubular necrosis typical of kidney shock syndrome. The lesions observed were suggestive of hypovolemic shock culm…

Elevated fetal plasma lactate produces polyhydramnios in the sheep.

In human fetuses with hemolytic diseases such as erythroblastosis fetalis, hydrops fetalis or polyhydramnios often develops. The mechanism(s) that produces these fluid imbalances is unknown, although lactate concentrations have been reported to be elevated in hydropic human fetuses with erythroblastosis. In this study we explored the role of lactate in producing fetal fluid imbalances. In seven near-term fetal sheep, we infused 5 mol/L sodium lactate at a rate of 10 mmol/hr for 3 days. Fetal plasma lactate rose by 6.0 +/- 1.0 (mean +/- SE) mmol/L above control. Fetal plasma osmolality and Na+ …

Immunisation against infections caused by Listeria monocytogenes in sheep.

Immunisation against listeriosis in sheep using a live, attenuated vaccine was introduced in Norway in 1984. Since then 65,000 to 80,000 animals have been vaccinated annually. Information obtained by a questionnaire showed that the incidence of listeriosis decreased from approximately 4.0 per cent before the introduction of the vaccine to 1.5 per cent after vaccination started. The incidence of abortions was 0.7 per cent in vaccinated flocks compared to 1.1 per cent in unvaccinated flocks. There were a few adverse reactions in the vaccinated sheep.

Some aspects of tick-borne diseases of British sheep.

The significance of tick-borne fever (TBF) and other tick-borne diseases of British sheep are reviewed. Experimental and field studies were carried out to clarify the role of TBF as a pathogen per se and as a predisposing factor in other diseases. Experimental TBF infection caused anorexia and depression in two- to three-week-old lambs, which under the stress of a hill environment could alone be a cause of mortality. Nine out of 10 lambs experimentally inoculated with Staphylococcus aureus during the febrile phase of a TBF reaction developed pyaemic lesions compared with four out of 20 lambs i…

Fetal cartilage xylosyltransferase activity and skeletal growth in sheep.

The activity of UDP-D-xylose:proteoglycan core protein beta-D-xylosyltransferase (EC 2.4.2.26), the enzyme that catalyzes the initiation of the polysaccharide chain linkage to the core protein of proteoglycans, was measured in costal cartilage from 20 fetal sheep of 65-138 days gestation. Activity of the enzyme was estimated from the transfer of [14C]xylose from UDP-[14C]xylose to silk as the acceptor protein. The specific activity decreased approximately 10-fold and was found to be highly correlated with the decremental rate of growth in length of the fetal vertebral column. These observation…

Характеристика агента скрипки, изолированного от овец в Японии.

Было отмечено, что патогенный агент, изолированный в мышах от мозга овцы, пораженной скрипчатой болезнью. Период инкубации болезни при первичной передаче от овец к мышам был более продолжительным, чем во вторичной и третичной передаче в том же штамме мышей. Прогрессивное разбавление инокулы вызвало продление периода инкубации. Инфекция вещества в 10% однородности головного мозга сохранялась, но снизилась примерно в 10 (3)−10(4) раза после нагрева при температуре 100 C в течение 30 минут. Гистологические изменения в мышечном мозге были связаны с вакуолизацией нервных клеток и дегенерацией губки

Совпадение в аннотации оригинала
A pathogenic agent isolated in mice from the brain of a sheep affected by scrapie-like disease was characterized. The incubation period of the disease in the primary transmission from the sheep to mice was longer than in the secondary and the tertiary transmission in the same strain of mice. Progressive dilution of the inoculum caused prolongation of the inc…