PubMed Health⌕ Search

Biomedical subjects

D C Edwards

Publications and source records attributed to D C Edwards.

At least 19 recordsLinked to original sources
PubMed1977

Immunogenic contaminants in mouse nerve-growth factor.

Experiments are described that confirm the presence of gamma-globulin in standard preparations of mouse nerve growth factor (7-S complex and beta subunit) and show that antibodies to this protein are present in horse antisera to the growth factor. These antibodies may be partially removed by adsorption with soluble antigen and totally removed by affinity chromatography on columns of insolubilised antigen. These procedures do not affect the potency of the antiserum in vitro or in vivo. Contaminating globulin may be removed from samples of the isolated beta subunit by gel filtration to give an immunochemically pure preparation which will permit more meaningful studies on nerve growth factor and its antiserum.

Animals↗
PubMed1975

Formation of virosomes from influenza subunits and liposomes.

The surface haemagglutinin and neuraminidase projections of influenza virus were removed from the viral envelope, purified, and relocated on the surface of unilamellar liposomes. The resulting structures were examined in the electron microscope and found to resemble the original virus. Units of both the viral haemagglutinin and viral neuraminidase could be discerned. The name virosome is proposed for these new bodies.

Hemagglutinins, Viral↗
PubMed1975

A study of the de- and regenerative changes in the sympathetic nervous system of the adult mouse after treatment with the antiserum to nerve growth factor.

In the adult mouse, the antiserum to nerve growth factor (NGF) induced marked atrophic changes of the ganglionic cell bodies in the superior cervical ganglion (SCG) and a disappearance of adrenergic nerve terminals in several peripheral tissues. By fluorescence histochemistry a lower-than-normal content of the noradrenaline (NA) transmitter was observed within the entire adrenergic neurone only 1 day after a single injection of NGF-antiserum (0.1 ml/g body weight). An atrophy of adrenergic nerve cell bodies and a disappearance of adrenergic nerve terminals were observed after 3 days, but the antiserum-induced effects did not appear maximally developed until 7 days after treatment. These fluorescence histochemical findings were paralleled by a gradual decrease of the endogenous NA levels in peripheral tissues and also of the weight of the SCG. A gradually proceeding restoration towards normal of the adrenergic innervation apparatus was observed fluorescence histochemically following a 5-day treatment with NGF-antiserum (0.1 ml/g body weight each dose), and after 6 weeks to 3 months a normal or close to normal fluorescence microscopical appearance was regained in the peripheral tissues and also in the SCG. These findings were parelleled by the results of the determinations of endogenous NA in peripheral tissues and by the results of weighing the SCG. We discuss some important differences between NGF-antiserum and 6-hydroxydopamine with respect to their mode of action on the mature sympathetic nervous system. Finally, we suggest that a decreased availability of NGF in a terminal area, due to an interference with endogenous NGF by NGF-antibodies, may temporarily result in an impaired function of the supplying adrenergic neurone, including a degeneration of nerve terminals.

Animals↗
PubMed1975

Within mode quality and intensity changes of habituated stimuli.

Habituation of skin conductance response (SCR) magnitude was established by a number of presentations of a short burst of moderate intensity white noise. The 6th, 11th, or 21st stimulus event was either a pure tone of unchanged loudness or another noise pulse of greatly reduced loudness. Mean SCR magnitude to the reduced intensity noise pulses was consistently smaller than that to the tones, but the difference of each of these response from the habituation curve varied with the number of prior habituation trials. The qualitative changes in the stimulus produced a consistent increase in SCR magnitude; the greater the number of prior habituation trials, the larger the difference from the habituation curve. The reduced intensity noise stimulus reduced SCR magnitude below that of the habituation curve at the 6th trial, equalled the curve at the 11th trial, and yielded a greater response than the habituation curve at the 21st trial test position. The response to the tone was superior to that to the reduced intensity noise by a constant amount over the three habituation curve test points.

Acoustic Stimulation↗
PubMed1975

Effects of nerve growth factors from mouse salivary glands and snake venom on the sympathetic ganglia of neonatal and developing mice.

1. Quantitative histological analysis has been made of the effects of nerve growth factor (NGF) from mouse submaxillary gland and from the venom of Vipera russelli on superior cervical ganglia of neonatal mice. 2. The hypertrophic and hyperplastic effects reported by other workers have been confirmed. 3. The hypertrophic effect arises from an increase in the rate at which the sympathetic neurones attain their mature size. The size at maturity is never exceeded. 4. The hyperplastic effect arises from an increase in the rate of production of neurones from less differentiated cells. In the developmental period, the number of neurones can exceed that found at maturity. If injection of NGF is discontinued the excess neurones disappear. 5. If injection of NGF is continued to maturity, the excess number of neurones is maintained.

Animals↗