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Biomedical subjects

A Stock

Publications and source records attributed to A Stock.

10 recordsLinked to original sources
PubMed1992

Localization of acidic fibroblast growth factor in specific subcortical neuronal populations.

The effects of fibroblast growth factors (FGFs) in vitro include the stimulation of mitogenesis in a variety of non-neuronal cell types and the promotion of the survival of various central and peripheral neuronal populations. The precise physiological role of FGFs in vivo is currently not known. As a step toward understanding the role of FGFs in the nervous system, the present study determined the distribution of acidic FGF (aFGF) in the rat CNS. The levels of aFGF in dissected areas of the nervous system were quantified using a biological assay method, and the cellular distribution of aFGF was determined in tissue sections using immunohistochemical methods. aFGF was found to be localized within specific neuronal populations in the CNS and was absent from non-neuronal cells. Neurons containing aFGF immunoreactivity included magnocellular neurons in the septal area and nucleus basalis; some additional defined neuronal groups in the subcortical telencephalon; specific neuronal populations in the hypothalamus, the thalamus, the substantia nigra, the reticular formation, and the pons; and motor and sensory neurons. Cerebral cortex and hippocampus contained only a very limited number of aFGF-immunoreactive neurons. A significant overlap of neuronal populations known to express the low-affinity NGF receptor (LNGFR) with populations containing aFGF immunoreactivity was also observed. These neuronal populations are known to be affected by neurodegenerative diseases, and the possible functional implications of the presence of aFGF and the LNGFR in these cells are discussed.

Animals↗
PubMed1991

Reconstitution of the bacterial chemotaxis signal transduction system from purified components.

In bacterial chemotaxis, transmembrane receptor proteins detect attractants and repellents in the medium and send intracellular signals that control motility. The cytoplasmic proteins that transduce information from the receptors to the flagellar motor have previously been purified and many of their enzymatic activities have been identified. Here we report the reconstitution of the complete signal transduction system from purified components. The protein kinase, CheA, plays a central role in both the initial excitation response to stimuli as well as subsequent events associated with adaptation. This kinase provides phosphoryl groups to two acceptor proteins, CheY, which interacts with the flagellar motor, and CheB, which demethylates the receptors. The purified aspartate receptor, Tar, reconstituted into phospholipid vesicles, acts in conjunction with an auxiliary protein, CheW, to stimulate the rate of kinase autophosphorylation greater than 10-fold. This stimulation is inhibited by aspartate. The activity of the kinase is increased by increased levels of receptor methylation. This effect provides a mechanism that explains how changes in receptor methylation mediate adaptive responses to attractant and repellant stimuli.

Adenosine Triphosphatases↗
PubMed1976

Assessment of urinary tract obstruction using a perfusion technique.

A perfusion technique is described which enables differentiation in a dilated upper urinary tract between one which is obstructed and one which is not. It has been found invaluable in the assessment of patients prior to surgical intervention and has saved many patients from an operation.

Adult↗
PubMed1975

Special diets in hospitals: discrepancy between what is prescribed and what is eaten.

An assessment has been made in four hospitals of the food eaten by 40 patients on special diets restricted in energy, carbohydrate, fat, protein, or sodium. The diets eaten by most patients were significantly different from those prescribed, partly because of patients' unrestricted access to food they possessed or could buy in the ward, but mainly because of the extra or alternative foods provided by ward staff. Not only may the patients, progress be prevented or hindered by excessive consumption but also the lack of progress may be interpreted as indicating that the dietary treatment has failed rather than that it has not been followed.

Attitude of Health Personnel↗