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Biomedical subjects

C Kay

Publications and source records attributed to C Kay.

At least 55 records · Page 3Linked to original sources
PubMed1986

Steroids and triiodothyronine reduce nerve growth factor concentrations in medium conditioned by L-929 fibroblasts.

Thyroid hormone, testosterone, and glucocorticoids stimulate the production of nerve growth factor (NGF) in mouse submandibular glands, but little is known about the influences of these hormones on other sources of NGF. In this study we tested the effects of thyroid hormone and steroids on NGF levels in medium conditioned by L-929 fibroblasts (L-cells), a mouse cell line that secretes NGF in culture. NGF concentrations in conditioned medium were measured by RIA and were normalized for cell number. In the absence of hormones, NGF levels in medium averaged 5.57 ng/ml. T3, cortisone, and aldosterone decreased NGF levels below the sensitivity of the RIA (less than 0.37 ng/ml), with respective ID50 values of 1 X 10(-5), 1 X 10(-8), and 5 X 10(-8) M. Testosterone decreased NGF levels by 66%, with an ID50 of 9 X 10(-9) M, and 17 beta-estradiol decreased it by up to 50%, although the hormone's effects had not plateaued at 10(-6) M. NGF concentrations were unaffected by progesterone at doses as high as 10(-6) M. Cell viability was unaffected by hormone treatment, and the total amount of secreted protein in medium decreased only in cultures treated with high doses of cortisone and aldosterone. Qualitatively similar results were obtained by bioassay; steroids markedly reduced, but did not eliminate, the nerve growth-promoting effects of L-cells on embryonic chick dorsal root ganglia in cocultures. These data indicate that hormones that stimulate NGF production in salivary glands inhibit NGF production by L-cells in culture.

Aldosterone↗
PubMed1981

An IgE inhibition assay for the detection of allergen specific IgE.

A method for the detection of specific IgE in human serum is described, using a modified radioimmune assay termed the Inhibition Assay Technique (IAT) The technique is based on the ability of specific IgE to bind with allergen. The difference in total IgE before incubation with the allergen and after incubation with the allergen gives a relative concentration of specific IgE to that particular allergenic substance. The assay has been shown to correlate with both the intradermal skin test as well as the standard RAST now used to determine specific IgE.

Allergens↗
PubMed1980

Enteric viruses in renovated water in Manitoba.

Using various concentration procedures (including the gauze pad method, ultrafiltration, and adsorption-elution), enteric viruses, mainly vaccine strains of polioviruses, were isolated from 61.8% of sewage, 20.5% of effluents, 3.0% of river water, and 6.7% of drinking water samples collected from a waterway system in Manitoba. The presence of polioviruses in the drinking water of the town utilizing this waterway was not correlated with an increase in the number of infectious diseases reported.

Enterovirus↗
PubMed1978

Wescodyne: lack of activity against poliovirus in the presence of organic matter.

The National Institute of Health Guidelines for Recombinant DNA Research recommends 2% aqueous Wescodyne, an iodophore that is used in many hospitals and laboratories as a disinfectant, as a decontaminant for biological safety cabinets and 5% for a spill outside a cabinet. A contact time of 10 to 15 minutes was given for the 2% solution and 20 minutes was considered adequate for the 5% concentration. The results indicate: 1. Aqueous Wescodyne (5%) is ineffective when used for 80 minutes against poliovirus in a test mixture containing 8.5% bovine serum albumin (a mixture equivalent in protein concentration to the higher range in serum). 2. Wescodyne (10%) employed under the same conditions for 40 minutes is also ineffective. 3. Wescodyne (10% v/v) in 50% ethanol (w/w) was effective and this mixture, originally recommended for hand washing, should be considered for use in biohazard situations, particularly for decontamination of work surfaces and biological safety cabinets. These results are of significance for if a virucide cannot inactivate poliovirus one would be concerned about using the virucide against hepatitis B or SV40 viruses.

Cells, Cultured↗
PubMed1977

Extravascular lung water accumulation in patients following coronary artery surgery.

We studied patients undergoing A-C Bypass with haemodilution. The bubble oxygenator was primed with either two units of plasma and lactated Ringer's solution (PLASMA) or with lactated Ringer's solution (RINGER'S) alone. We found no difference in pulmonary function or lung water determinations between the Ringer's and the Plasma groups. When all patients were grouped together we found no significant increase in lung water (ETVL)5 immediately post-operatively. This suggests lung water did not increase during cardiopulmonary bypass. By the following morning there was a highly significant increase in lung water which was related to changes in the balance between hydrostatic pressure and colloid osmotic pressure and which continued through the second post-operative day. Pulmonary dysfunction, as measured by gas exchange, was not a major problem except in one patient whose lung water increase exceeded 3 ml H2O/kg of total body weight (52 per cent increase) and in whom there was increased shunting. We consider the increase in lung water important, since it may reduce lung compliance and further lung water accumulation. Since the increased lung water was associated with a change in the balance of Starling's forces (PMV - COPMV), treatment designed to reduce that balance should reduce lung water accumulation.

Adult↗
PubMed1976

Psychiatric morbidity in general practice and the community.

The "General Health Questionnaire" was used to assess the psychiatric morbidity among 365 consecutive attenders at a general practice and to compare this with a systematic random sample of 213 patients drawn from the lists of the same practice. Those attending a general practitioner are shown to be more psychiatrically disturbed than a random sample of the practice population, and this difference remains when those attending for psychological symptoms are discounted. Various social and demographic characteristics which distinguish between those who do and those who do not attend a doctor with a given set of psychological symptoms are described.

Adult↗
PubMedDate not supplied

The importance of internal quality control data in National External Quality Assessment schemes. Plasma progesterone assays.

Co-ordinators of external quality assessment schemes in the U.K. despatch samples of quality control material to participant laboratories at frequent intervals to assess laboratory performance. We show, via a controlled experiment on the plasma progesterone assay, that the current analysis performed by the external assessors is inadequate and often leads to erroneous conclusions about a laboratory's performance. It is concluded that for a proper assessment of a laboratory's performance, the external assessor should prepare large pools of plasma and distribute them to all participants in the scheme to use as internal quality control material.

Chemistry Techniques, Analytical↗