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Biomedical subjects

O Williams

Publications and source records attributed to O Williams.

63 records · Page 4Linked to original sources
PubMed1991

Phosphorylation of murine CD8 alpha is not essential for responses of T cell hybridomas to antigen.

CD8 T cell differentiation antigens, expressed on class I-restricted T cells, have a key role in the control of recognition and response of these cells to antigen. It has been suggested that these molecules function as co-receptors together with antigen-specific T cell receptors to regulate T cell responses. We have addressed the question of whether cytoplasmic serine phosphorylation, which occurs on CD8 molecules after activation by antigen or phorbol esters, is relevant to its co-receptor function. By mutagenesis, we show that phorbol ester-induced phosphorylation occurs exclusively on CD8 alpha serine residue 216. However, inhibition of CD8 polypeptide phosphorylation does not appear to have a detrimental effect on several responses of CD8-dependent transfectants to antigen. This is in contrast to results reported with CD4 (N.Glaichenhaus, N.Shastri, D.R. Littmann and J.M.Turner. 1991. Cell, 64:511), suggesting that CD4 and CD8 molecules may play somewhat different roles in the control of T cell activation.

Animals↗
PubMed1989

Spouse abuse: social learning, attribution and interventions.

Forty male respondents, 20 batterers and 20 non-batterers comparably matched for education, sex, age, employment, and occupation in a non-probabilistic sample, were administered the Conflict Tactics Scale and the Causal Dimension Scale in order to measure exposure to violence in both family and non-family environments and to determine how respondents attributed the cause of spousal conflict. The results demonstrate that batterers were exposed to violence in non-family environments, particularly with their friends, and did not differ with respect to exposure to violence and suggestions are made with respect to points of intervention.

Adult↗
PubMed1975

Diagnosis of deep venous thrombosis using a Doppler ultrasonic technique.

A consecutive series of 118 patients was studied postoperatively by Doppler ultrasonic techniques and by either venography or radioiodinated fibrinogen. When using the latter diagnostic measures, 22 patients were shown to have deep venous thrombosis, an incidence of 18.6 per cent. The Doppler ultrasonic technique showed that 21 patients had deep venous thrombosis, an incidence of 17.7 per cent. When the patients diagnosed as having deep venous thrombosis by two separate methods were compared, it was shown that the Doppler technique gave two false-positive results and three false-negative results. It is concluded that this technique is accurate, and because of its convenience, lack of complications and ability to be repeated frequently, it should be the preferred screening technique for the diagnosis of postoperative deep venous thrombosis.

Doppler Effect↗
PubMed1974

Ventilation-perfusion lung scanning for pulmonary emboli.

The conventional method of lung scanning detects defects of pulmonary artery perfusion. False positive results occur because regions of hypoventilation, such as are present in obstructive airways disease, also cause defects of perfusion. The converse is not true, however, as defects of perfusion continue to be ventilated. Thus in pulmonary embolism ventilation-perfusion discrepancy (normal ventilation and impaired perfusion) occurs.We have assessed the clinical value of this discrepancy. Out of 18 patients with ventilation-perfusion discrepancy 14 had a final diagnosis of pulmonary emboli, whereas in none of the 34 patients without the discrepancy was this final diagnosis made. We conclude that combined ventilation-perfusion lung scanning distinguishes pulmonary emboli from other lung conditions such as asthma and bronchitis which cause impaired pulmonary perfusion. The false positive rate was only 4% overall and 7.7% in patients with perfusion defects.

Airway Obstruction↗
PubMedDate not supplied

The development of humoral immunological memory to a T-cell-dependent antigen requires thymic emigrant cells.

Immunological memory is embodied in the rapid and enhanced immune responsiveness to previously encountered antigens. Classically, memory would depend on the presence of small resting long-lived specific lymphocytes which, through clonal expansion after priming with antigen, would be present at higher frequencies than in naive animals. Here we report that T-cell-reconstituted athymic mice, which lack recent thymic emigrants, mount a primary response to a T-cell-dependent antigen, but do not develop memory or the capacity to produce specific anti-TNP IgG1 antibodies during the secondary immune response. On the other hand, if thymocytes are continuously provided during the secondary response, a typical secondary immune response is achieved with high levels of specific IgG1. These results lead us to propose that the development of humoral immunological memory cannot be explained solely by the long life span of primed T lymphocytes, but is rather a dynamic state dependent on the continuous presence of recent thymic emigrants and qualitative functional differences in responder T cells.

Animals↗