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Biomedical subjects

T Stewart

Publications and source records attributed to T Stewart.

At least 73 records · Page 4Linked to original sources
PubMed1993

An outbreak of hepatitis A among homosexual men in Melbourne.

OBJECTIVE: To describe an outbreak of hepatitis A virus (HAV) infection that occurred in Melbourne in 1991. DESIGN: (i) We reviewed Health Department Victoria surveillance data from 1989 to 1991 (primary surveillance) and identified all notified cases of HAV infection with an onset of illness between 1 January and 31 December 1991 (secondary surveillance data). (ii) We studied HAV seroprevalence in Melbourne among homosexual men attending gay venues. RESULTS: (i) In the two years 1989-1990 there were only 55 notifications of HAV infection to Health Department Victoria, with a male:female ratio of 1.2:1. Of the 495 notifications for 1991, 407 (82%) were male, of whom 210 (52%) were known to be homosexual. Many reported sexual and social contact at Melbourne's gay venues and with the Sydney gay community. (ii) Of men attending gay venues, 27% had serological evidence of past infection with HAV, compared with 45.8% in a 1981 Melbourne study. CONCLUSION: The outbreak of HAV infection in Victoria largely affected homosexual males in their sexually active years. Contact with the Sydney gay community was commonly reported.

Adult↗
PubMed1993

Peptide stability in drug development. II. Effect of single amino acid substitution and glycosylation on peptide reactivity in human serum.

The determination of peptide stability in human serum (HS) or plasma constitutes a powerful screening assay for eliminating unstable peptides from further development. Herein we report on the stability in HS of several major histocompatibility complex (MHC)-binding peptides. Some of these peptides are in development for the novel treatment of selected autoimmune disorders such as rheumatoid arthritis and insulin-dependent diabetes. For most of the l-amino acid peptides studied, the predominant degradation mechanism is exopeptidase-catalyzed cleavage. Peptides that were protected by d-amino acids at both termini were found to be more stable than predicted, based on additivity of single substitutions. In addition, N-acetylglucosamine glycopeptides were significantly stabilized, even when the glycosylation site was several amino acids from the predominant site(s) of cleavage. This indicates that long-range stabilization is possible, and likely due to altered peptide conformation. Finally, the effect of single amino acid substitutions on peptide stability in HS was determined using a model set of poly-Ala peptides which were protected from exopeptidase cleavage, allowing the study of endopeptidase cleavage pathways.

Acetylglucosamine↗
PubMed1993

A case of acquired stammering: the pattern of recovery.

A case is presented of a 21-year-old student who demonstrated sudden onset of severe stammering speech. The findings of speech assessments over a 1-year period post-onset are described and discussed. In addition a comprehensive description of the client's own perceptions of her difficulties during the same time scale is recounted. The case demonstrates a possible pattern of recovery and the profound psychological implications in the event of acquired stammering in adulthood.

Acute Disease↗
PubMed1992

Scuba tanks as a compressed air source in positive-pressure ventilation.

Throughout the developing world there is a general problem of ensuring regular deliveries of medical supplies to hospitals. This includes the supply of compressed gases. At one regional hospital in Vanuatu, we were faced with the problem of how to provide economically a source of compressed gas at regulated pressure to drive an anaesthetic ventilator. We eventually adapted the output from a Scuba cylinder for this purpose. This paper describes the simple modifications necessary and suggests other uses for this source of compressed air that could be implemented in hospitals with small to medium case loads and access to a diving compressor.

Diving↗
PubMed1992

Influenza surveillance in general practice.

This paper describes a survey of influenza conducted in general practice from July to October 1990. The study demonstrates how interested general practitioners can be involved in community based surveillance for the early detection of influenza outbreaks.

Adolescent↗
PubMed1991

The treatment of neuroleptic malignant syndrome. Are dantrolene and bromocriptine useful adjuncts to supportive care?

In a prospective study of 20 patients with NMS, those who received dantrolene (2 patients) or bromocriptine (2 patients) or both (4 patients) tended to have a more prolonged course of illness and a greater incidence of sequelae than those treated with supportive care alone. These results do not indicate a useful role for dantrolene or bromocriptine in the treatment of NMS.

Adult↗
PubMed1990

Loss of pancreatic islet tolerance induced by beta-cell expression of interferon-gamma.

Interferon-gamma (IFN-gamma) is produced during the response to infection and participates in immunostimulatory events. We have previously reported the induction of diabetes in transgenic mice (ins-IFN-gamma) in which the expression of the lymphokine IFN-gamma is directed by the insulin promoter. This diabetes is a result of the progressive destruction of pancreatic islets that occurs with the influx of inflammatory cells. Here we demonstrate that this islet cell loss is mediated by lymphocytes, that engrafted histocompatible islets are destroyed, and that lymphocytes from the transgenic mice are cytotoxic to normal islets in vitro. These results indicate that the pancreatic expression of IFN-gamma can result in a loss of tolerance to normal islets, consistent with its role as an inducer of costimulatory activity, which is essential for lymphocyte activation during an immune response.

Animals↗
PubMed1989

Immunohistologic demonstration of type II collagen in synovial fluid phagocytes of osteoarthritis and rheumatoid arthritis patients.

We were able to demonstrate type II collagen in synovial phagocytes of osteoarthritis (OA) and rheumatoid arthritis (RA) patients, using a monoclonal antibody to human type II collagen and immunoperoxidase staining. In addition, using immunoelectron microscopy, we demonstrated labeled fragments in synovial phagocytes of both RA and OA patients. This immunohistochemical assay may prove to be a sensitive indicator of cartilage erosion in patients with OA and RA.

Adult↗
PubMed1989

A prospective analysis of 24 episodes of neuroleptic malignant syndrome.

The authors prospectively studied 24 consecutive cases of neuroleptic malignant syndrome occurring in 20 patients in a general hospital over a 6-year period. They present detailed data concerning the clinical setting in which neuroleptic malignant syndrome occurs, the associated clinical and laboratory features, the favorable outcome that can be achieved with vigorous supportive therapy, and the factors that might help predict whether patients with neuroleptic malignant syndrome will subsequently be able to tolerate the reintroduction of neuroleptic medication.

Adolescent↗
PubMed1988

Specific active lung cancer immunotherapy. Immune correlates of clinical responses and an update of immunotherapy trials evaluations.

The mechanisms of action of the specific active immunotherapy of solid tumors have not been defined. In an attempt to characterize some of these mechanisms, we report controlled studies of humoral immune responses and cell-mediated immune (CMI) responses in lung cancer patients with Stage I and Stage II adenocarcinoma and squamous cell cancer receiving pure tumor-associated antigen (TAA) specific active immunotherapy or combination immunochemotherapy. At 5 to 6 months postimmunotherapy, the humoral immune response measurements are predictive of response to therapy/survival in early lung cancer patients, permitting decisions as to whether to continue therapy. Patients with adenocarcinoma respond to combination chemoimmunotherapy by showing stronger or earlier responses to tests of immunity. Cell-mediated immunity to TAA at 17 to 24 months was far greater in patients receiving immunotherapy or immunochemotherapy compared with control patients, and also correlated with early humoral immune response and with 5-year survival. Here we report a further subset analysis of Stage I and Stage II lung cancer patients in a successful Phase III US specific active immunotherapy trial as substantiating the experience with Stage I patients in a successful Phase II Canadian trial. We analyze failures and suggest additional therapies, especially a chemoimmunotherapy trial indicated by our analyses of humorocellular immune variables reported here.

Adenocarcinoma↗
PubMed1988

Toxicity study of continuous administration of physostigmine salicylate.

The present study demonstrates that continuous administration with physostigmine salicylate (0.12 or 0.24 mg/kg/hr via mini-osmotic pumps) induces toxicities (e.g., body weight loss, decreased water consumption, tremors, decreased body temperatures, mortality) in guinea pigs. Both blood and brain cholinesterase activity is inhibited dose-dependently by physostigmine salicylate. The signs of toxicity in the guinea pigs which received the low dose appeared within 2 or 3 days and then the animals recovered, while toxic signs in the guinea pigs treated with the high dose of the drug persisted throughout the experiments. The study further shows that continuous administration of physostigmine salicylate also caused down-regulation of muscarinic receptors in the striata of the guinea pigs.

Acetylcholinesterase↗
PubMed1988

General practice geriatric surveillance scheme.

This project converted an on-demand, crisis intervention service into a doctor-initiated, anticipatory, preventive programme to improve management, based on home visiting and 'activities of daily living' screening by state enrolled nurse, with serial medical assessment and regular surveillance by the general practitioner. Opportunistic and domiciliary organised, standardised, serial, numerically scored, medical, social and functional assessment of list patients over 75 years, allowed comparison over time and identification of high need/risk patients--focus for anticipatory service and aids provision. 24% healthy, 41% moderately impaired and 35% high risk patients were contacted or visited annually, six-monthly and quarterly respectively. Patient-initiated calls decreased by 41% but additional surveillance input increased work load by 9% per annum. Improved standards of care helped patients live longer at home however. The nurse proved effective and economical in this role.

Activities of Daily Living↗
PubMed1987

Diagnostic value of knee extension torque tracings in suspected anterior cruciate ligament tears.

The purpose of this study was to determine the diagnostic accuracy of knee extensor muscle torque tracings in patients suspected of having damage to the anterior cruciate ligament of the knee joint. The knee extensor torque tracings of 30 patients suspected of having anterior instability of the knee joint were reviewed independently for abnormalities believed to be associated with anterior cruciate ligament damage. These results were compared blindly with an arthroscopic evaluation. The diagnostic accuracy of the torque tracing approach was determined by calculating the prevalence, sensitivity, specificity, and positive and negative predictive values. The sensitivity and specificity were calculated to be 25.0% and 85.7%, respectively. These results suggest that the curve patterns examined in this article have poor diagnostic accuracy and are of little benefit as a clinical diagnostic aid.

Adult↗