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Biomedical subjects

M K Nicholas

Publications and source records attributed to M K Nicholas.

25 records · Page 2Linked to original sources
PubMed1986

Comparison of T8+ cell-mediated suppressor and cytotoxic functions in multiple sclerosis.

Patients with progressive multiple sclerosis (MS) and controls were compared with regard to: (a) in vitro pokeweed mitogen (pwm)-induced IgG secretion, as an indirect measure of T8+ cell-mediated suppressor function; (b) alloantigen-directed cytotoxic activity, a predominantly T8+ cell-mediated function. The MS group had increased IgG secretion (4790 +/- 372 ng/ml vs. 1866 +/- 233 ng/ml, P less than 0.001) compared to controls. In contrast, alloantigen-directed cytotoxic activity did not differ between MS and control groups. These results suggest a selective defect of suppressor cell function in MS rather than a generalized dysfunction of T8+ cells. Defective immunoregulatory control coupled with preserved effector functions may contribute to the autoimmune process, suspected to underlie the pathogenesis of MS.

Adult↗
PubMed1986

Suppressor and cytolytic cell function in multiple sclerosis. Effects of cyclosporine A and interleukin 2.

Patients with progressive multiple sclerosis (MS) demonstrated persistent reductions in levels of concanavalin A (Con A)-induced suppressor activity and heightened levels of in vitro pokeweed mitogen (PWM)-induced IgG secretion. The reduced Con A suppressor activity could not be reversed by addition of interleukin 2 (IL-2). Cyclosporine A (CsA) treatment did not alter the defect in Con A-induced suppressor activity, but did markedly inhibit T8+ cell-mediated alloantigen directed cytolytic activity; this latter defect was reversible by in vitro addition of IL-2. CsA-treated patients did not differ from placebo-treated patients with regard to levels of PWM-induced IgG secretion or proliferative responses of their mononuclear cells to Con A. The results indicate that CsA treatment of MS patients reduces cytolytic function from baseline normal values, but does not alter aberrant suppressor cell function.

Adult↗
PubMed1986

Dissociation of T8+ cell-mediated cytolytic and suppressor functions in young adults.

In the normal young adult population, in vitro levels of polyclonally-induced IgG secretion by mononuclear cells (MNCs) vary widely amongst individuals. Levels of IgG secretion correlate with functional suppressor activity of T8+ cells but not with their proportion within the MNCs either prior to culture, or as found in this study, at the end of the culture period. The current study also demonstrates a lack of correlation between T8+ cell-mediated suppressor (Ts) function and a second predominantly T8+ cell-mediated function, alloantigen-directed cytolytic (Tc) activity. Whether this dissociation between Ts and Tc functions reflects quantitative differences in subsets contained within the T8+ population or qualitative differences in the mechanisms required for induction or generation of Ts and Tc remains to be established.

Adult↗
PubMed1984

Passage of cows' milk protein in breast milk.

An enzyme-linked immunosorbent assay has been used to search for lactoglobulin and bovine casein in breast milk. Initial results suggest this may be a simple and useful method for such studies. Detection and prevention of antigen passage could influence the prevalence of atopic disease.

Animals↗
PubMed1983

Characteristics, attitudes and personalities of AI donors.

The first 50 men recruited to an artificial insemination by donor (AID) programme have been assessed for their attitudes and characteristics using a basic questionnaire and a standard well evaluated personality inventory. The results have shown that donors can be characterized as stable and moderately extroverted people who come from a wide range of occupations. Their marital and parental status had no particular relationship to their desire to donate and most of them volunteered for altruistic reasons, financial remuneration being a poor inducement. Most subjects lived within the close environs of the Westmead Centre and preferred to donate during normal working hours. The inconvenience of donating appeared to be the most important factor in considering new approaches to recruiting semen donors.

Adult↗
PubMed1983

Some attitudes to artificial insemination by donor.

A preliminary survey to assess and quantify attitudes to Artificial Insemination by Donor (AID) has been conducted with the aid of an article in a national magazine. The consensus of 375 individuals (mostly with a vested interest in infertility) concerning their attitudes to semen donation, hypothetical receipt of donor semen, legal aspects and the keeping of donor records, etc., have been analysed and their answers correlated to their age, sex, ethnic grouping, educational level, religion, and marital and fertility status as well as their place of residence. Within the limitations of this study, three major conclusions can be drawn. Firstly there are probably many potential semen donors in the general community and recruitment techniques need to be improved to capitalize on this source. Secondly, a centralized non-identifying National Register of donor information may be tolerated, and finally, the couples questioned felt an AID child should not be likened to one received through adoption. These and other findings would suggest that attitudes towards AID are changing and consequently some of the practices within AID programmes may need to be altered. Further statistically conducted surveys are warranted to determine these current attitudes.

Adult↗