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Failure to detect scrapie virus in sheep at slaughter in a highly endemic region of France.

A study was carried out in a sheep slaughterhouse located in a region of France where scrapie has been endemic for several decades. Neuropathological examination of 63 randomly selected lambs and adult sheep revealed no scrapie-related abnormalities, and inoculation of mice with brain, tonsil, lateropharyngeal ganglia, and intestine from the same animals did not transmit scrapie. The failure to detect any evidence of scrapie infection in commercially-bred sheep, the absence of an increased mortality rate for human CJD in the surrounding consumer region, and the absence of a single case of CJD …

The effect of carbonic anhydrase inhibition on breathing movements and electrocortical activity in fetal sheep.

Fetal breathing movements (FBM) indicated by repetitive negative intrathoracic pressures and biparietal electrocorticograms (ECoG) were recorded from 8 fetal sheep for 3 h before (control) and 3 h after the administration of a carbonic anhydrase inhibitor, acetazolamide. FBM and the low voltage (LV) ECoG state occurred 36 +/- 5% (SEM) and 60 +/- 3% of the control period, respectively. Virtually no FBM occurred during high voltage (HV) ECoG while in 57 +/- 6% of the LV state the fetuses were making FBM. The peak magnitude of the negative intrathoracic (tracheal) pressure deflections was 4 +/- 1…

A serological survey for Bhanja and tick-borne encephalitis viruses in sheep of eastern Slovakia.

755 sheep from 41 farms in the districts of Trebisov, Michalovce, Humenné and Roznava in the East Slovakian region were investigated on the presence of antibodies to Bhanja (neutralization test) and tick-borne encephalitis (haemagglutination-inhibition test) viruses. In respective districts 2.2%, 0.4%, 1.7% and 26.7% of animals (total 5.3%) were found to be positive on Bhanja virus, 4.4%, 1.5%, 1.7% and 5.0% (total 2.6%) on tick-borne encephalitis (TBE) virus. The considerable infection rate in sheep with Bhanja virus in the district of Roznava (mean 26.7%-on one farm as high as 63.9% serologi…

Proglumide: selective antagonism of the rumination but not gastric motor effects induced by pentagastrin in sheep.

The effect of intravenous (IV) vs intracerebroventricular (ICV) administrations of pentagastrin on gastro-intestinal motility and rumination were investigated by electromyography in sheep; these effects were compared to those obtained after a previous IV or ICV injection of proglumide. When ICV administered at a dose of 20 ng X kg-1, pentagastrin did not significantly affect the frequency of reticular and abomasal spiking activity but elicited a 13 to 37 min period of rumination after a delay of 23 +/- 7 min. In contrast, when IV infused at a rate of 20 ng X kg-1 X h-1 during 20 min, pentagast…

Effects of dietary copper and molybdenum on tansy ragwort (Senecio jacobaea) toxicity in sheep.

Dried tansy ragwort (Senecio jacobaea), which contains pyrrolizidine alkaloids (PA), was fed to sheep to determine whether PA consumption influenced liver Cu concentrations. Nine Polypay wether lambs were allotted to 3 groups according to the diets: control diet + 50 micrograms of Cu/g of feed (control + Cu); tansy ragwort (TR) diet + 50 micrograms of Cu/g of feed (TR + Cu); and TR diet + 50 micrograms of Cu/g of feed and 10 micrograms of Mo/g of feed (TR + Cu + Mo). Liver Cu concentrations were sharply increased (13-fold) after 8 weeks of feeding the diets, and then decreased slightly. There …

Tension receptors with vagal afferent fibres in the proximal duodenum and pyloric sphincter of sheep.

Single-unit afferent activity was recorded from the hepatic-duodenal branch of the vagus nerve of chloralose-anaesthetized sheep during acute electrophysiological experiments. The impulse activity of sixty-seven slowly adapting mechanoreceptors situated in the muscularis externa of the proximal duodenum and pyloric sphincter was synchronous with alterations in electromyographic and tension records. Afferent units were excited during passive distension, compression and drug-induced increases in muscle tension, thus satisfying the criteria for 'in series' tension receptors (Iggo, 1955). From the…

Influence of heat stress on exercise-induced changes in regional blood flow in sheep.

Radioactive microspheres were used to measure cardiac output and blood flow to most major tissues in sheep at rest and during treadmill exercise (3- to 6-fold increase in metabolic rate for 30 min) in thermoneutral (TN) [dry bulb temperature (Tdb) = 16 degrees C, wet bulb temperature (Twb) = 12 degrees C] and mildly hot (MH) (Tdb = 40 degrees C, Twb = 23 degrees C) environments. During exercise, rectal temperature increased more under MH than under TN conditions; exercise-induced changes in the major central cardiovascular parameters were unaffected by MH. Exercise in TN caused mild hypocapnia…

Passive protection of mice and sheep against bluetongue virus by a neutralizing monoclonal antibody.

A murine hybridoma antibody, 6C2A.4.2, previously characterized as an immunoglobulin G class 2a that binds in radioimmunoassay to bluetongue … death of neonatal mice. Antibody 6C2A.4.2-containing ascitic fluid was injected intravenously into sheep that were later inoculated with BTV-17. These sheep remained free of clinical signs, did not develop viremia or detectable levels of antibodies reactive in the immunodiffusion test used for routine BTV diagnosis in the United States, and developed o …

Foetal and maternal rates of urea production and disposal in well-nourished and undernourished sheep.

1. Five monotocous and two ditocous Scottish Blackface ewes with indwelling catheters in an umbilical artery and vein of one foetus only and in both maternal jugular veins were used. 2. Experiments were conducted over a period of 2 d when [14C]urea was infused intravenously over 9 h into either the mother or foetus, separate days being used for each infusion. Two series of experiments were completed, one in well-nourished and the other in undernourished sheep at 125-141 and 138-143 d of gestation respectively. 3. Plasma urea specific radioactivities of the mother and infused foetus at plateau …

Nucleoside translocation in sheep reticulocytes and fetal erythrocytes: a proposed model for the nucleoside transporter.

1. Nucleoside transport by fetal erythrocytes from nucleoside-permeable and nucleoside-impermeable type new-born lambs and by reticulocytes from adult sheep was compared with that of mature erythrocytes from adult sheep of the two phenotypes.2. Fetal cells and reticulocytes transported [U-(14)C]uridine rapidly, with little difference between cells from the two types of sheep. Transport occurred by a saturable uptake mechanism with similar properties to that present in mature cells from adult nucleoside-permeable type animals, except for an approximately 100-fold higher V(max).3. This increased…

The ovipositional response of the Australian sheep blowfly, Lucilia cuprina, to fleece-rot odours.

The ovipositional response of Lucilia cuprina flies to odours emanating from fleece-rot lesions of greasy wool in which Pseudomonas aeruginosa bacteria proliferated, was studied. Fractionation of the fleece-rot odours was carried out by bubbling the volatile components through hydrochloric acid and sodium hydroxide solutions to remove basic odours and acidic odours respectively. It was found that the acidic/neutral odours of fleece-rot wool, when perfused into wet, greasy wool stimulated L. cuprina to oviposit. On the other hand, the basic/neutral odours of fleece-rot wool were virtually unatt

Protein, prostaglandin and steroid synthesis in caruncular and intercaruncular endometrium of sheep before implantation.

The effect of the presence of a preimplantation embryo on protein concentration, rate of protein synthesis, beta-glucuronidase and acid phosphatase activities, steroid metabolism and prostaglandin F production in caruncular and intercaruncular tissue have been studied for sheep at Day 15 of pregnancy. The rate of protein synthesis in both tissues was greater in pregnant than in non-pregnant animals, although the difference was only significant in caruncular endometrium. The effect in caruncular tissue was mimicked in ovariectomized animals treated with oestradiol. Localized changes in the caru…

Differences in airway reactivity in normal and allergic sheep after exposure to sulfur dioxide.

The effect of breathing 5 ppm sulfur dioxide (SO2) on airway reactivity was studied in both normal and allergic conscious sheep. Allergic sheep were defined as animals in which inhalation of Ascaris suum extract resulted in bronchospasm as evidenced by an increase in mean pulmonary flow resistance (RL), hyperinflation, and a fall in dynamic compliance. Airway reactivity was assessed by measuring the increase of RL after 18 breaths of 0.25% carbachol (c), from an initial RL value obtained after 18 breaths of buffered saline (s) [RL(c-s)]. RL and RL(c-s) were determined prior to, immediately aft…

Effect of a constant arterial CO2 tension on respiratory pattern in hear-stressed sheep.

Sheep were exposed in a climate chamber to a hot humid environment under two conditions: breathing atmospheric air and breathing air enriched with CO2. Measurements were made of rectal temperature (Tre), respiratory frequency (fR), mean arterial pressure (BP), heart rate (fH), and arterial O2 tension (PO2), CO2 tension (PCO2), and pH; depth of breathing was also estimated. Tre increased at a similar rate under both conditions. When breathing air, sheep exhibited rapid shallow panting followed by slower deeper (second phase) breathing during which they became severely hypocapnic and alkalotic. …

Иммуносоппрессия в токсоплазмозе: исследования на овцах с вакцинами от хламидиального аборта и вируса взрыва.

Инфекция токсоплазмы гонди была установлена у овец за семь дней (приемная инфекция) или за 28 дней (хроническая инфекция) до того, как они получили вакцину от энзоотического аборта (EAE) самостоятельно или одновременно с вакциной от взрыва (LI). Неинфекционный контроль получил такой же график вакцинации. Серологическая реакция сильно зараженных токсоплазмой овец на первоначальную вакцинацию ЛИ была значительно подавлена, однако через четыре недели после повторной вакцинации эти овцы продемонстрировали такую же реакцию, как и ревакцинированные средства контроля. Зараженные овцы также значительн

Совпадение в аннотации оригинала
Toxoplasma gondii infection was established in sheep seven days (acute infection) or 28 days (chronic infection) before they were given enzootic abortion (EAE) vaccine alone or simultaneously with louping-ill (LI) vaccine. Uninfected controls received the same vaccination schedule. The serological response of acute toxoplasma-infected sheep to initial LI vac…

Measurements of the partial pressure of oxygen in the carotid body of fetal sheep and newborn lambs.

The partial pressure of oxygen in chemoreceptors tissue of the carotid body was measured in parallel with arterial oxygen tension in eleven sheep fetuses exteriorized from 9 ewes anaesthetized with pentobarbitone, in 6 of these fetuses in the transitional period following occlusion of the umbilical cord and the start of artificial pulmonary ventilation and in 6 naturally born lambs, 10-36 h old. In the fetal carotid body, O2 gradients were very small and, in the majority of tests, the arterial-to-tissue O2 difference was small or negligible. During the transitional period, this difference incr…

[Blood concentrations of sulfadimidine after the internal use of depot sulfadimezine granules in sheep].

A granular premixed form, called sulphadimesin-depot-granules, was produced, containing 40% of sulphadimine inserted into a hydrophobic matrix of hydrogeneric sunflower oil. After a single internal insertion into sheep by means of a stomach-tube or of a bottle on an empty stomach in a dose of 0.5 g/kg t, they caused bacteriostatic concentrations in blood plasma during 78 hours, and in a dose of 1.0 g/kg t--during 96 hours, whereas the sulphadimesin in tablets, applied in a dose of 0.2g/kg t, kept up a therapeutic concentration for 24 hours. The duration of the bacteriostatic level of sulphadim…

[Effects of intracerebroventricular injections of nalorphine on feeding behaviour and rumination in sheep (author's transl)].

Two sheep were fitted with permanent cannulus in the first cerebral ventricule and permanent electrodes were stitched to the wall of the reticulum. They were housed in individual pens and fed lucern pellets twice a day (total duration 1.30 hour) at fixed hours. Food intake was weighed. Chewing movements were recorded permanently by means of a submandibular balloon. Reticular motility was recorded by electromyography during feeding periods. Feeding behaviour and rumination were previously recorded during two control periods. No treatment was applied during the first control period of 6 days (Ta…