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Biomedical subjects

T S Wilson

Publications and source records attributed to T S Wilson.

At least 19 recordsLinked to original sources

Age-related changes in levels of tyrosine kinase B receptor and fibroblast growth factor receptor 2 in the rat inferior colliculus: implications for neural senescence.

Brain-derived neurotrophic factor and fibroblast growth factor 2, and their respective binding sites, tyrosine kinase B receptor and fibroblast growth factor receptor 2, are known to regulate neurite outgrowth and antioxidant enzyme activity. Several studies suggest that brain-derived neurotrophic factor and fibroblast growth factor are contained in the inferior colliculus. Previous work in our laboratories revealed dendritic and synaptic losses in the inferior colliculus of aged Fischer-344 rats, along with coincident increases in lipid peroxidation possibly linked to a decrease in activity of antioxidant enzymes. In an effort to identify potential causal mechanisms underlying age-related synaptic and dendritic losses that occur in the inferior colliculus, the present study attempted to determine if inferior colliculus levels of tyrosine kinase B receptor and fibroblast growth factor receptor 2 expression are altered with age. Immunocytochemistry was performed in the inferior colliculus, hippocampus and cerebellum of 3-month-old F344 rats to study distributions of the full-length and truncated isoforms of tyrosine kinase B receptor, and fibroblast growth factor receptor 2. The latter two brain regions served as positive controls. For all three antigens, immunolabeling was localized primarily in somata and proximal dendrites in all subdivisions of the inferior colliculus, and in the dentate gyrus and Ammon's horn of the hippocampus. In the cerebellum, the somata and dendrites of the Purkinje cells were also immunolabeled.A significant reduction in levels of the full-length form of tyrosine kinase B receptor in 18- and 25-month-old rats (respectively, approximately 20% and 30% relative to 3-month-olds) was revealed using western blot analyses. Inferior colliculus and hippocampal levels of the truncated form were modestly decreased ( approximately 7%) as well in the two older age groups. In contrast, levels of fibroblast growth factor receptor 2 in the inferior colliculus and hippocampus were elevated by approximately 35% in the two older age groups when compared to 3-month-olds. Changes in cerebellar levels of tyrosine kinase B receptor and fibroblast growth factor receptor 2, while similar to those in the inferior colliculus and hippocampus among the age groups, did not achieve statistical significance in this study. These findings give rise to the possibility that age-related reductions in tyrosine kinase B receptor levels could be a causal factor in the degenerative changes observed in the inferior colliculus of aged animals, including mitochondrial damage and dendritic regression. The observed increases in fibroblast growth factor receptor 2 levels may be compensatory to the increased oxidative stress. The effectiveness of the fibroblast growth factor receptor 2 response is questionable given the damage that occurs in the inferior colliculus and hippocampus of aged animals. However, the deficits could worsen in the absence of an increase in fibroblast growth factor receptor 2.

Aging↗

LASIK surgery.

The laser in situ keratomileusis (i.e., LASIK) procedure reshapes the surface of the cornea to focus visual images directly onto the retina, thereby improving visual acuity. In 1998, approximately 420,000 LASIK procedures were performed in the United States, and approximately two million people throughout the world already are benefiting from the LASIK vision correction procedure.

History, 20th Century↗

An outbreak of Salmonella enteritidis phage type 4 infection in a rural community in Northern Ireland.

An outbreak of gastroenteritis arose in people who attended a charity barbecue at a hotel in a rural area of Northern Ireland in July 1995. About 120 people attended the barbecue, 98 of whom were identified. Fifty-one of them and seven members of hotel staff met the case definition. An epidemiological investigation showed that illness was significantly associated with eating foods containing mayonnaise that had been prepared using raw shell eggs and stored at too high a temperature. Salmonella enteritidis phage type 4 was cultured from 17 out of 24 faecal specimens received from people who attended the barbecue and in 17 out of 34 faecal specimens from staff, including all seven staff cases. The primary source of infection was not identified despite thorough investigation. This paper highlights the value of administering questionnaires by telephone when investigating community outbreaks of infection in rural areas, the important role of general practitioners in the identification of community outbreaks, and the need to periodically reiterate public health messages, in particular for food handlers and caterers.

Bacteriophage Typing↗

Salmonella in retail poultry in Northern Ireland.

A prospective survey was carried out in Northern Ireland between February and August 1994 to assess the current levels of salmonella in retail chickens, and to determine whether contamination rates differed between chickens sold in supermarkets and by butchers. One hundred and forty chilled and frozen raw chickens were sampled from retail display and examined for the presence of salmonella using an approved method. Contamination was commoner in chickens that were chilled, sold from smaller premises, and reared or slaughtered outside Northern Ireland. Salmonella enteritidis phage type 4 was the most commonly isolated type. The contamination rate of about 7% is considerably lower than in Great Britain and this may partially explain the lower rate of human salmonella infections in Northern Ireland. This finding supports the recommendations made in the Advisory Committee on the Microbiological Standards of Food's report on poultry meat, since many of the improvements proposed are already in operation in areas of the Northern Ireland poultry industry.

Animals↗

Investigation of a nosocomial outbreak of Pseudomonas aeruginosa pneumonia in an intensive care unit by random amplification of polymorphic DNA assay.

From July to September 1993 in the intensive care unit of the Royal Victoria Hospital there were 10 cases of pneumonia associated with sputum culture of Pseudomonas aeruginosa. The isolates had an identical biotype and pyocine typing profile. The same strain of P. aeruginosa was recovered from the sink plug-hole in two rooms, and the tap handles and ventilator tubing in a third room. All strains were retrospectively typed by the random amplification of polymorphic DNA (RAPD) method using a 26-mer oligonucleotide primer, and were identical in profile. Recommendations to medical and nursing staff included secretion isolation precautions, terminal disinfection after patient discharge, use of disposable vinyl gloves by hospital staff for all body substance contacts, thorough handwashing with 4% chlorhexidine gluconate before and after dealing with all patient contacts, and prompt, appropriate antibiotic treatment for P. aeruginosa pneumonia. RAPD is a simple and effective method to determine the relatedness of P. aeruginosa isolates, and typing results are available within a single working day; thus dramatically increasing its clinical relevance over existing molecular methods.

Bacterial Typing Techniques↗

Assessment of skeletal muscle viability by PET.

UNLABELLED: We investigated the use of [18F]fluoro-2-deoxyglucose (FDG) PET scanning for assessment of skeletal muscle viability in patients with peripheral vascular disease and in patients following free-flap skeletal muscle transfer for closure of open wounds. METHODS: We obtained 32 FDG-PET scans from 30 patients, either at the time of admission for peripheral vascular disease (n = 16) or between 1 and 15 days after surgery for skeletal muscle transfer (n = 16). Ratios between injured and contralateral limb FDG tracer activity uptake were correlated with clinical outcome at 1 mo to 3 yr follow-up. RESULTS: Viable muscle uptake ratios ranged from 0.47 to 7.88 (mean: 2.26 +/- 1.81; n = 26), while nonviable muscle uptake ratios ranged from 0.12 to 0.46 (mean: 0.27 +/- 0.12; n = 6; p < 0.02). After skeletal muscle transfer, two patients with viable tissue, as documented by PET, required amputation due to osteomyelitis, and one patient with peripheral vascular disease who showed viable tissue by PET required amputation 3 mo after the PET scan because of recurrent ulcers. CONCLUSION: FDG-PET scanning can determine skeletal muscle viability in patients with peripheral vascular disease and in patients following free-flap transfer.

Adolescent↗

The effects of HIV/AIDS intervention groups for high-risk women in urban clinics.

OBJECTIVE: This study reports the results of a behavior change intervention offered to women at high risk for human immunodeficiency virus (HIV) infection seen in an urban primary health care clinic. METHODS: Participants were 197 women randomly assigned to either an HIV/acquired immunodeficiency syndrome (AIDS) risk reduction group or a comparison group. Women in the HIV/AIDS intervention group attended five group sessions focusing on risk education; skills training in condom use, sexual assertiveness, problem solving, and risk trigger self-management; and peer support for change efforts. Women in the comparison group attended sessions on health topics unrelated to AIDS. RESULTS: At the 3-month follow-up, women in the HIV/AIDS intervention group had increased in sexual communication and negotiation skills. Unprotected sexual intercourse had declined significantly and condom use had increased from 26% to 56% of all intercourse occasions. Women in the comparison group showed no change. CONCLUSIONS: Socially disadvantaged women can be assisted in reducing their risk of contracting HIV infection. Risk reduction behavior change interventions should be offered routinely in primary health care clinics serving low-income and high-risk patients.

Adolescent↗

Immunoglobulin G (IgG) serological response to Branhamella catarrhalis in patients with acute bronchopulmonary infections.

Over 12 months serum was collected from 45 inpatients, with acute bronchopulmonary infection, in whose sputum Branhamella catarrhalis predominated, or was the sole pathogen. Serum was examined for IgG against B catarrhalis using an immunofluorescence antibody test. Acute and convalescent sera were compared with sera of age and sex matched controls. The convalescent sera had significantly higher titres than the acute sera which in turn had higher titres than the controls. The findings confirm the role of B catarrhalis as a respiratory pathogen and suggest that patients with chronic pulmonary disease are more prone to infection with this organism than the general population.

Acute Disease↗