Experimental pestivirus infections in newborn goat kids

Two experiments were carried out in which 37 healthy newborn goat kids were inoculated with a non-cytopathic ovine (BDV) or a cytopathic bovine pestivirus (BVDV) by intramuscular or intracerebral injection. No kids showed signs of disease or gross lesions which could be attributed to these viruses, but inoculated kids had lower mean growth rates than the controls. Significant histological changes in the CNS of 14 kids were restricted largely to the white matter and consisted mainly of hypercellular foci comprising microglial/histiocytic cells and mild perivascular infiltration by mononuclear cells. Varying degrees of infiltration of the myocardium by lymphocytes and plasma cells were observed. All kids remained negative for neutralizing antibodies against pestivirus until 2 to 3 weeks after infection. Titres increased during the following weeks. Pestiviruses were recovered from kids necropsied 10 days after inoculation, but not from any kids killed 20 days after inoculation or later. Non-cytopathic virus was isolated from various tissues of four kids that had received BDV and three kids that had been given BVDV. Cytopathic viruses were not recovered from any kids. Mean white blood cell counts in all kids were within the normal range at 4 and 8 weeks after inoculation. The lymphocyte response to stimulation by phytohaemagglutinin was significantly increased on both sampling occasions in the BDV-inoculated kids, while in the BVDV-inoculated animals, a similar increase was seen only at 8 weeks.     

Influence of partial hepatectomy on the renal response to isotonic saline loads in conscious rats

Summary If injected into the superior pancreatico-duodenal artery secretin, pancreozymin, histamine and Decholin^® each significantly increases the amount of blood flowing through the artery and the pancreatic tissue. The relationship between the logs of the drug doses and their effects are linear. Whereas to histamine and Decholin^® all dogs respond with the same rise in pancreatic blood flow, to pancreozymin the rate of increase was similar in all dogs and to secretin the rate of increase differs from one animal to the other.     

Effects of intraruminal loads of saline or water followed by voluntary drinking in the dehydrated lactating goat

In five goats water deprivation for 26 h increased plasma osmolality, total plasma protein concentration, and plasma vasopressin (AVP) concentration to higher levels during lactation compared to nonlactation. At the end of the dehydration period intraruminal loads of saline or water (corresponding to 50% of the body weight loss) were given to lactating goats. The saline load decreased the plasma protein concentration below control levels, while plasma osmolality, Na concentration and AVP did not change. After the water load the plasma protein concentration stayed elevated. Plasma osmolality, Na concentration and AVP fell, but remained significantly above control levels. Both plasma renin activity (PRA) and aldosterone (PA) concentration increased after water, but decreased after saline administration. Three hours after the fluid loads the goats were offered water to drink. AVP decreased at the sight of water. After drinking, plasma osmolality, Na and AVP continued to decrease in water loaded animals, and fell also in saline loaded goats. PRA remained elevated, and PA increased in water loaded goats, while these hormones still were depressed in saline loaded goats. Mean renal 'free water clearance' became positive after drinking in both groups. It is concluded that the water losses with the milk cause lactating goats to become dehydrated more rapidly than non-lactating goats during water deprivation. Lowering of the plasma osmolality and Na concentration are more important than restoration of the plasma volume in suppressing the high plasma AVP concentration in the dehydrated lactating goat. The water diuresis, which occurred after voluntary drinking, indicates that the goats had not been able to anticipate their water deficit accurately.(ABSTRACT TRUNCATED AT 250 WORDS)     

Control strategies using diclazuril against coccidiosis in goat kids

Coccidiosis is probably the main parasitic disease affecting goat kids around the weaning period, leading to high economic losses in goat production due to deaths and delayed growth rates of infected animals. A total of 101 kids of 2-4 weeks of age, naturally infected with Eimeria spp., were divided into five groups and studies were conducted to analyse the effects of metaphylactic administration of diclazuril (Vecoxan?) on parasitological and productive parameters. Two different doses of diclazuril (1 and 2 mg/kg BW, p.o.) were given either at 3 weeks (single treatment) or at 3 and 5 weeks of life (double treatment). The faecal oocyst shedding and the body weights of the animals were monitored at 2-weeks intervals for 6 consecutive weeks. Treatments of goat kids with diclazuril were effective against the three most predominant Eimeria species recorded in this study (E. arloingi, E. ninakohlyakimovae and E. christenseni) and also against other minor species found in faecal examinations, including E. alijevi, E. caprina, E. jolchijevi, E. caprovina, E. hirci and E. aspheronica). In consequence, OPG values lower than 1?×?10(3) were detected in 90 to 100% of the animals up to 15-20 days post-treatment depending on the treatment regimen. Even a single dose of 1 mg/kg BW p.o. resulted in an increase of growth rates in treated animals and therefore should be considered as a control strategy in farms precluding coccidian infections, whilst double and multiple dose treatments could be the recommendation for environments heavily contaminated with Eimeria oocysts. In relation to the OPG reduction and increased growth rates, the severity of the clinical signs (i.e., diarrhoea) was ameliorated in treated animals during the course of infection compared to that of non-treated or control kids. The precise timing of treatment appears crucial in order to prevent severe clinical coccidiosis and thereby enabling the adequate development of protective immune response against Eimeria challenge infections.     

Plasma atrial natriuretic peptide (ANP) concentration and fluid balance during rapid intravenous saline infusions in camels

Human muscle samples were obtained with the percutaneous biopsy technique. The samples were membrane-hyperpermeabilized (skinned) using a chemical or freeze-drying technique. Short single fibre segments were dissected from the sample, transferred to an experimental chamber, connected to a force transducer and manipulator, and exposed to temperature-controlled solutions. The force generating-capacity, the sensitivity of the contractile apparatus to calcium and the caffeine threshold for calcium release from the sarcoplasmic reticulum could be studied in the short muscle fibre segments obtained from man with the percutaneous muscle biopsy technique. The average length of the fibre segments between the connectors was 0.44±0.21 mm. Thus, detailed studies of the contractile machinery can be made on human skinned muscle fibres with only minimal discomfort to the patient or subject during biopsy, which should be useful in studies of neuromuscular disease, muscle plasticity or in applied physiology.     

Rib response and breakage due to anteroposterior loads

The purpose of this investigation is to determine the loading conditions required for rib breakage as might occur in automobile accidents or in cardiopulmonary resuscitation. Analytical modelling is coupled with the results of experimental tests on postmortem dogs to predict the effects of loading rate on rib response. Dynamic impedance tests were performed on both extracted and in situ dog ribs to obtain natural frequencies and those rib response characteristics which are dominant in a given frequency range. Ligament stiffness at the costovertebral joint were estimated. Compression of each individual rib was also performed to determine its contribution to overall thoracic stiffness and its required deflection for failure. A three-dimensional dynamic model for the rib based on vibrations of the circular ring is given which conforms well with rib geometry and includes damping effects of surrounding tissues and the elasticities of the costovertebral joint. The dynamic model was found to adequately predict rib static stiffness, first natural frequency and forced frequency response. Based on the dynamic impedance tests of the dog, the inertia effects of the rib were found to be minimal for all important cases of anteroposterior loading. Thus, the ribcage exhibits predominantly elastic and viscous properties.     

Early recognition of newborn goat kids by their mother: I. Nonolfactory discrimination

Mother sheep and goats develop an early bond with their neonate on the basis of olfactory recognition. We investigated whether goats were also able to show early (<24 hr postpartum) nonolfactory discrimination of their kids, as already reported in sheep. In a first experiment, we found that goats are not able to recognize their kid at 1 m away on the basis of olfactory cues alone. By contrast, they showed a significant preference for their own kid in a two-choice test as early as 4 hr postpartum, and prepartum maternal anosmia did not impede the ability of mothers to show discrimination. We conclude that goats, like sheep, are fully able to discriminate their neonate without the help of olfactory cues very early after parturition. The difference in the early spatial mother-young relationship between the two species due to the different behavior of the young (kids = hiders, lambs = followers), is not associated with marked differences in the dynamics or mechanisms controlling the development of recognition of the neonate by its mother.     

Binding sites for atrial natriuretic peptide (ANP) on cultured pituicytes: lack of effect of ANP on release of neurohypophysial hormones in vitro

Receptors for atrial natriuretic peptide (ANP) are known to be present in the posterior pituitary gland and this is a possible site of action of ANP to modulate neurohypophysial hormone release. Pituicytes cultured from adult rat neurohypophyses are shown to possess high affinity binding sites for ANP, suggesting that in vivo a population of neurohypophysial ANP receptors are present on these astrocytic glial cells. alpha-rANP (1-100 nM) did not modulate the basal or electrically stimulated release of oxytocin or vasopressin from the isolated neurohypophysis in vitro. The physiological significance of the glial ANP binding sites thus remains unknown.     

Accidental death due to erroneous intravenous infusion of hypertonic saline solution for hemodialysis

The case of a continuous hemodialysis patient who died shortly after erroneous infusion with undiluted hypertonic solution is reported. Autopsy showed small parenchymal hemorrhages in all organs. Although producers take measures to prevent such errors by hospital staff, further steps are suggested for types of dialysis requiring reinfusion of large quantities of reinfusion hemodialysis solution.     

The secretion of gastric acid in response to a lack of metabolizable glucose

1. The onset of the secretion of acid from the stomach of rats during insulin-induced hypoglycaemia has been found to correspond to a mean plasma glucose concentration of 72 mg/100 ml. (equivalent to a blood glucose concentration of 44 mg/100 ml.).2. Infusions of the non-metabolizable sugar, 3-O-methylglucose, into rats with denervated adrenal glands caused a large and sustained rise in the gastric acid output. This gastric acid secretion could be prevented by prior vagotomy or stopped, when previously established, by cutting the vagi or by the administration of glucose.3. A consistent relationship was demonstrated between the plasma concentration of glucose and the total concentration of glucoses (glucose plus 3-O-methylglucose) in the plasma at the onset of gastric acid secretion during the infusion of 3-O-methylglucose into these rats. The theoretical basis for this relationship is discussed.4. 3-O-methylglucose did not cause the release of gastric acid when infused into rats with intact sympathetic nervous systems owing to the effects of the secretion of adrenaline provoked by this agent.5. The qualitative and quantitative similarities between the factors governing both the secretion of gastric acid and the release of adrenaline in the absence of a sufficiency of metabolizable glucose are discussed. It is suggested that the reactions of both these systems under such circumstances are determined by chemoreceptors which possess identical characteristics.