In this study, the biological properties of the replication-competent viruses, F-MuLVA, present in the anemia-inducing isolate of Friend leukemia virus complex (FV-A); and F-MuLVP, present in the polycythemia-inducing isolate of Friend leukemia virus complex (FV-P) have been examined. BALB/c mice infected as newborns with clonal isolates of F-MuLVA or F-MuLVP become anemic and show splenic enla...

immunohistochemistry, we studied the presynaptic muscarinic autoreceptor subtypes controlling ACh release in the neuromuscular junctions of the newborn (3-6 days postnatal) and adult (30-40 days) rat. In the Levator auris longus muscles of both newborn and adult rats, acetylcholine release was modified by the M1receptor selective antagonists pirenzepine (10 μM) and MT-7 (100 nM) and by the M2-r...

We examined whether nitric oxide (NO) generated from neuronal NO synthase (nNOS) contributes to the reduced ability of the newborn to autoregulate retinal blood flow (RBF) and choroidal blood flow (ChBF) during acute rises in perfusion pressure. In newborn pigs (1-2 days old), RBF (measured by microsphere) is autoregulated over a narrow range of perfusion pressure, whereas ChBF is not autoregul...

Mice lacking granulocyte colony-stimulating factor (G-CSF) are neutropenic with reduced hematopoietic progenitors in the bone marrow and spleen, whereas those lacking granulocyte-macrophage colony-stimulating factor (GM-CSF) have impaired pulmonary homeostasis and increased splenic hematopoietic progenitors, but unimpaired steady-state hematopoiesis. These contrasting phenotypes establish uniqu...

Cretinism is a term frequently applied to forms of thyroid deficiency occurring in utero or early in extra-uterine existence. Experimental cretinism probably had its beginnitgs in the first recorded extirpation of the thyroid in young animals, which seems to have been performed by Raynard' in 1834. Two years later, Astley Cooper' published his observations on thyroid extirpation in pups. His an...

Attempts were made to transmit O. volvulus infection to small laboratory animals and several species of primates to identify a practical laboratory host for human onchocerciasis. Infective larvae of O. volvulus of Guatemalan origin were inoculated into the following animals: rhesus monkeys, bonnet monkeys, golden spider monkeys, black spider monkeys, galagos, opossums, jirds, newborn and adult ...

In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV) started at the end of 2011. The objectives of this study were to describe clinical symptoms of SBV infection, the effect of infection on mortality rates, and reproductive performance in sheep, as well as to identify and quantify flock level risk factors for ...

BACKGROUND AND PURPOSE Although indomethacin has been demonstrated to prevent germinal matrix and intraventricular hemorrhage in clinical and animal studies, the mechanism of action of this agent to prevent hemorrhage remains unclear. Previous studies have demonstrated both that the microvessels in the germinal matrix of newborn beagle pups undergo basement membrane maturation during the first ...

This paper deals with the refractoriness of PET \ mouse integument to the subcutaneous administration of nerve growth factor. Newborn mice were injected once daily with NGF through ten injections. Gross and histological examination showed that the skin of the experimental animals was completely unresponsive to this agent. No alterations in the hair growth cycle or pattern were ·observed.

Diving mammals share with fetal and newborn animals a high resistance to asphyxia when compared, respectively, with terrestrial and adult animals. Adaptations for conservation or sparing of oxygen and for adjustment to the effects of accumulated metabolic products, such as carbon dioxide and hydrogen ions, have been discovered in both diving marine mammals and asphyxiated terrestrial species. T...