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T Whitehead

Publications and source records attributed to T Whitehead.

At least 19 recordsLinked to original sources
PubMed2001

Direct and indirect bacterial killing functions of neutrophil defensins in lung explants.

Studies of the antimicrobial activity of neutrophil defensins have mostly been carried out in microbiological media, and their effects on the host defense in physiological conditions are unclear. We examined 1) the antibacterial activity of defensins in physiological media with and without lung tissue present, 2) the effect of defensins on hydrogen peroxide (H(2)O(2)) production by lung tissue that had been exposed to bacteria, and 3) the effect of diphenyleneiodonium (DPI), an inhibitor of reactive oxygen species formation, on the antibacterial activity of defensins in the presence of lung tissue. Defensins were incubated with Escherichia coli or Pseudomonas aeruginosa in the absence or presence of primary cultured mouse lung explants. Defensins reduced bacterial counts by approximately 65-fold and approximately 25-fold, respectively, at 48 h; bacterial counts were further decreased by approximately 600-fold and approximately 12,000-fold, respectively, in the presence of lung tissue. Defensins induced H(2)O(2) production by lung tissue, and the rate of killing of E. coli by defensins was reduced by approximately 2,500-fold in the presence of 10 microM DPI. We conclude that defensins exert a significant antimicrobial effect under physiological conditions and that this effect is enhanced in the presence of lung tissue by a mechanism that involves the production of reactive oxygen species.

Animals↗
PubMed2000

Ethics in the classroom: a reflection on integrating ethical discussions in an introductory course in computer programming.

In this paper, we describe our recent approaches to introducing students in a beginning computer science class to the study of ethical issues related to computer science and technology. This consists of three components: lectures on ethics and technology, in-class discussion of ethical scenarios, and a reflective paper on a topic related to ethics or the impact of technology on society. We give both student reactions to these aspects, and instructor perspective on the difficulties and benefits in exposing students to these ideas.

California↗
PubMed1997

Coding component important element of compliance plan.

In recent years the U.S. government has increased its fraud and abuse investigations in all sectors of the healthcare community. Healthcare providers that are successfully prosecuted may be excluded from the Medicare programs and are liable for monetary penalties. The best course of action is for providers to have a comprehensive compliance plan in place. An important element of such a plan is a component that will identify and address problematic coding issues.

Abstracting and Indexing↗
PubMed1993

Serum urate as a free radical scavenger in diabetics.

We have looked at the relationship between serum urate and the molar equivalent serum antioxidant capacity (MESA) in diabetic and normal individuals who attended St Bartholomew's Hospital diabetic clinic and BUPA Health Screening Centre, London, and have compared serum antioxidant capacity between the two groups. Sample response curves showed less serum antioxidant potential in diabetics than in nondiabetics, and a linear relationship between serum urate and MESA. Simple regression analysis gave a correlation coefficient of 0.9 (p < 0.0001). Significant differences between the two groups were found for both mean MESA values (p < 0.0001) and mean uric acid levels (p < 0.005).

Diabetes Mellitus, Type 1↗
PubMed1990

One path to a comprehensive district psychiatric service.

Brighton, which never had its own large psychiatric hospital, now has a comprehensive community psychiatric service. Sarah Hood and Tony Whitehead describe the development of the service and argue that the closure of large hospitals need not and should not result in the neglect or exploitation of former patients.

Aged↗
PubMed1990

Carotid patch angioplasty: immediate and long-term results.

To determine the benefit of carotid patch angioplasty, a retrospective study of 1000 consecutive carotid endarterectomies was done. Based on the type of carotid endarterectomy closure, patients were divided into four groups: 250 had primary closure, 250 had expanded polytetrafluoroethylene patch, 250 had Dacron patch, and 250 had saphenous vein patch. On the basis of operative technique or type of carotid artery closure, no statistical difference was found in the incidence of postoperative stroke (p greater than 0.25): primary closure 1.6% (4), expanded polytetrafluoroethylene 2.0% (5), Dacron patch 1.6% (4), and saphenous vein patch (0). Postoperative carotid patency was determined by B-mode ultrasonography, and 717 patients were evaluated in follow-up extending to 6 years (mean 37.8 months). Based on the method of carotid endarterectomy closure, no significant difference (p greater than 0.25) was found in the incidence of significant restenosis (greater than 50% diameter reduction): primary closure 4.0% (7), expanded polytetrafluoroethylene 4.0% (6), Dacron 5.4% (9), and saphenous vein 1.0% (2). Significant restenosis was most frequent in habitual smokers (93%, 25/28) and females (78%, 22/28) despite the method of carotid endarterectomy closure. No statistical difference was found in the incidence of late ipsilateral stroke either (p greater than 0.25): primary closure 2.9% (5), expanded polytetrafluoroethylene 2% (3), Dacron 5% (3), and saphenous vein 0%. These results indicate that the incidence of postoperative stroke, regardless of method of arterial closure, was not statistically different. The method of carotid closure did not appear to affect the occurrence of late ipsilateral stroke or restenosis; however, patch angioplasty with saphenous vein appears appropriate in habitual smokers, and likely in patients with small internal carotid arteries.

Blood Vessel Prosthesis↗
PubMed1988

Sequential development of aneuploidy, keratin modifications, and gamma-glutamyltransferase expression in mouse skin papillomas.

To elucidate the role and timing of expression of different premalignant and malignant markers in tumor promotion, we correlated alterations in keratin patterns and gamma-glutamyltransferase (GGT) expression with the chromosomal status of individual mouse skin papillomas. Papillomas were induced by 7,12-dimethylbenz[a]anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate promotion. Individual tumors were randomly sampled at 20 and 35 weeks of promotion. Each tumor was cytogenetically analyzed and serial paraffin sections were used for GGT detection, immunoblotting, and immunohistochemistry studies. Monospecific antibodies elicited against keratins K1 (Mr 67,000) and K14 (Mr 55,000) were used to analyze keratin modifications. Most tumors at 20 weeks of promotion, although exhibiting aneuploidy, still presented high levels of the K1 differentiation-associated keratin. Later during promotion those tumors bearing the highest aneuploidy indexes were those that showed a marked decrease in or absence of the K1 protein. Furthermore, those same tumors with the highest levels of genomic alterations also exhibited foci of GGT activity. These results support the idea that the majority of papillomas under continuous promotion are progressing toward malignancy. Aneuploidy seems to precede detectable keratin modifications, and GGT activity appears to be the latest marker to be expressed.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Difficult people.

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Dangerous Behavior↗