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Biomedical subjects

S Whittaker

Publications and source records attributed to S Whittaker.

At least 55 records · Page 3Linked to original sources
PubMed1996

IL-6 acts on endothelial cells to preferentially increase their adherence for lymphocytes.

Using a quantitative monolayer adhesion assay, the current report shows that treatment of human umbilical vein endothelial cells (HUVEC) with IL-6 increases their adhesiveness for blood lymphocytes, particularly CD4+ cells, but not for polymorphonuclear cells and monocytes. This effect, which was most pronounced when using low concentrations of the cytokine (0.1-1.0 U/ml) and a short incubation period (4h), was also apparent with microvascular endothelial cells and a hybrid endothelial cell line. Skin lesions from patients with mycosis fungoides contain high levels of IL-6, and blood lymphocytes from patients with this disorder also exhibited an enhanced adhesion to IL-6-treated HUVEC. The cytokine enhanced intercellular adhesion molecule-1 (ICAM-1) expression and induced the expression of vascular cell adhesion molecule-1 (VCAM-1) and E-selectin on endothelial cells. Antibody blocking studies demonstrated that the vascular adhesion molecules ICAM-1, VCAM-1 and E-selectin and the leucocyte integrin LFA-1 all contributed to lymphocyte binding to endothelium activated by IL-6. It is proposed that IL-6 may be involved in the recruitment of lymphocytes into non-lymphoid tissue.

Adjuvants, Immunologic↗
PubMed1996

T-cell receptor gene analysis in cutaneous T-cell lymphomas.

An essential property of the immune system is its ability to generate diverse antibody and T-cell mediated responses to virtually any potential foreign particle. The basic molecular mechanisms responsible for producing this extensive diversity have now been elucidated. Each T cell expresses a unique membrane bound T-cell antigen receptor (TCR) which combines with specific antigenic peptides and major histocompatibility complex molecules. The characterization of TCR usage now represents a focal point for many studies of inflammatory and neoplastic disorders. Such studies are helping to clarify the pathogenesis of T-cell mediated diseases and provide the basis for the development of specific therapies. This paper will review several techniques used to identify neoplastic T-cell clones in cutaneous T-cell lymphoma. Similar methods may be used to analyse TCR gene usage in cutaneous inflammatory dermatoses.

Base Sequence↗
PubMed1995

p53 immunoreactivity is uncommon in primary cutaneous lymphoma.

p53 gene mutation appears to play an important role in the development of systemic lymphoma, and may be associated with tumour progression. Its role in cutaneous lymphoma is currently unknown. We examined p53 expression in 55 biopsies of cutaneous lymphoma, including patch-, plaque- and tumour-stage mycosis fungoides (MF), T- and B-cell lymphoma and lymphomatoid papulosis. Strong, homogeneous p53 expression, thought to correlate most closely with p53 gene mutation, was seen in only three cases; in a plaque and tumour from a patient with tumour-stage MF, in plaque-stage MF in a patient without tumours, and in one case of CD30+ large-cell anaplastic lymphoma. These data suggest that p53 gene mutation is not a critical step in the development of the majority of primary cutaneous lymphomas.

Humans↗
PubMed1994

Coronary angioplasty in high risk patients with percutaneous cardiopulmonary support.

Cardiopulmonary Support (CPS) was employed electively in 13 patients during high risk percutaneous transluminal coronary angioplasty (PTCA) in accordance with a selection criteria, which included at least two of the following; (i) left ventricular ejection fraction of less than 35%, (ii) target vessel(s) supplying more than 50% of the viable myocardium, and (iii) patients refused coronary bypass surgery. The mean age of the patients was 56.8 +/- 10.7 years (range 39-77). PTCA was attempted in a total of 35 lesions in 12 patients; 29 lesions were successfully dilated (technical success rate of 82.9%). On average, 2.7 lesions were attempted in each patient, and 2.2 lesions were successfully dilated per patient. In one patient the procedure was abandoned due to dissection of the iliac artery during cannulation. One patient died of a large pulmonary embolism 72 h after the procedure. All the surviving 11 patients who had successful PTCA on CPS showed symptomatic improvement during a mean follow-up period of 18.5 +/- 4.3 months (range 11 to 24 months). The commonest complication encountered following the CPS-assisted PTCA was local haematoma (nine of 13 patients), but all patients required transfusion due to significant periprocedural blood loss. Our early experience suggests that CPS enhances the safety of undertaking PTCA in high risk patients.

Adult↗
PubMed1994

Chondromyxoid fibroma of a metatarsal and cuneiform.

The occurrence of chondromyxoid fibroma in the foot is relatively rare, and it is highly unusual for the lesion to involve the epiphysis. The authors report a case of a highly aggressive tumor occurring in the first metatarsal bone, crossing the epiphysis and invading the medial cuneiform bone. A literature search did not reveal previous cases of chondromyxoid fibroma in this unusual location.

Adult↗
PubMed1994

Control of an amoebiasis outbreak in the Philippi area near Cape Town.

Previous studies in Durban have shown that serological investigations, in combination with iso-enzyme electrophoresis, are invaluable for monitoring the endemicity of pathogenic strains of Entamoeba histolytica. We therefore proposed that antibody profiles could be used to detect epidemic situations. An outbreak of amoebiasis in the normally non-endemic Philippi area near Cape Town provided an opportunity for testing this hypothesis. Seven of 9 patients presenting at a district hospital with invasive amoebiasis originated from a single farm in Philippi. Iso-enzyme electrophoresis and serological investigations were used to monitor the endemicity of amoebiasis on 16 of the 49 farms in this district. In an attempt to contain disease transmission all inhabitants on farms from which patients came (including those where cyst-passers were identified) and all seropositive subjects were treated. The antibody profiles proved invaluable for confirming that the farm from which the hospitalised patients originated was the central focus of the outbreak, and also identified subjects infected with pathogenic zymodemes of E. histolytica on the adjacent 4 farms. On all 5 of these farms, 62.5-100% of seropositive subjects were strongly positive. In contrast weak to negative serological responses occurred on the remaining 11 farms. In addition the success of treatment was indicated by a notable drop in strong seropositive responses on the affected 5 farms to 11.5% within 9 months. The infection pathways implied that the pathogenic strain of E. histolytica was introduced into this non-endemic area by a foreigner from an endemic area; this suggests that the pathogenicity of E. histolytica is an immutable stable feature.

Animals↗
PubMed1993

Mortality and cancer incidence in patients with dermatitis herpetiformis: a cohort study.

One hundred and fifty-two patients in whom a diagnosis of dermatitis herpetiformis was made at St John's Hospital for Diseases of the Skin, London, during 1950-85, were followed from the date of diagnosis to the end of 1989 for mortality, and from 1971, or the date of diagnosis if later, to 1986 for cancer incidence. Thirty-eight deaths occurred under the age of 85, slightly fewer than expected on the basis of national general population rates [standardized mortality ratio (SMR) = 87; 95% confidence interval (CI) 61-119]. All-cause mortality was somewhat lower in patients who had followed a gluten-free diet (SMR = 51; 17-120) than in those who had not (SMR = 97; 66-136), but the difference in SMRs was not significant (P = 0.3). Cancer mortality was non-significantly below expectations from national rates (SMR = 72; 31-142), but cancer incidence was significantly increased [standardized registration ratio (SRR) = 394; 180-749]. No particular cancer site accounted for the cancer incidence excess. One death occurred from cancer of the small intestine (SMR = 4953, P = 0.04), and one lymphoma was incident (SRR = 1555, P = 0.12). Increased risks of these malignancies have previously been found to be associated with coeliac disease (which is present in many patients with dermatitis herpetiformis), and with dermatitis herpetiformis, respectively. Mortality from ischaemic heart disease (IHD) was significantly below national rates (SMR = 37; 95% CI 12-86), and was similar in patients who had followed a gluten-free diet and those who had not.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Cardiac resuscitation with percutaneous cardiopulmonary support.

Percutaneous cardiopulmonary support (CPS) was initiated in 9 patients to provide haemodynamic stability after failure of conventional resuscitation. 4 patients were in cardiogenic shock and 4 remained in asystole, with 1 in resistant ventricular fibrillation, after cardiac arrest. During CPS for those in cardiogenic shock, the mean intra-arterial pressures ranged from 65 to 100 mm Hg (mean 84), at flow rates of between 3 to 5 l/min (mean 3.9). 2 patients underwent technically successful coronary angioplasty. No patient in this group survived. In the cardiac arrest group, acceptable mean intra-arterial blood pressures were achieved (mean 95, range 90-100 mm Hg) at flow rates of between 2 to 3 l/min (mean 2.6). All 5 subjects underwent technically successful coronary angioplasty whilst on CPS. 4 survived. 2 were alive and well at 12 months follow-up, 1 of whom had returned to work; the third is alive and well at 4 months.

Aged↗
PubMed1992

Phenytoin-induced pseudolymphoma. A report of a case and review of the literature.

We report a patient with phenytoin-induced pseudolymphoma mimicking cutaneous T-cell lymphoma (CTCL). Despite withdrawal of phenytoin, there was persistence of the cutaneous eruption and lymphadenopathy. Southern blot analysis of immunoglobulin and T-cell receptor genes was therefore used to assess whether there was a clonal lymphoid expansion. However, no rearrangement of the beta T-cell receptor gene or immunoglobulin heavy-chain gene was detected in tissue DNA from skin and lymph nodes. One year later the patient became asymptomatic, although he is still at risk of developing a true malignant lymphoma in the future, a condition known as pseudo-pseudolymphoma. It is suggested that genotypic studies may help in the initial diagnosis and the subsequent management of such patients.

Adult↗
PubMed1992

Ineffectiveness of AIDS education and HIV antibody testing in reducing high-risk behaviors among injection drug users.

The effectiveness of education in reducing high-risk human immunodeficiency virus (HIV) transmission behaviors was examined in 313 injection drug users. Involvement in high-risk behaviors was assessed via structured interview at study entry and 4 months following the intervention. Subjects were randomly assigned to (1) AIDS education, (2) AIDS education with optional HIV antibody testing, or (3) a wait list. The sample as a whole decreased its involvement in high-risk behaviors, but there were no significant differences as a function of experimental group assignment.

AIDS Serodiagnosis↗
PubMed1991

Frail aged persons residing in South African homes for the aged who require hospitalisation. Part I. Urban areas.

The numbers and characteristics of white residents identified by medical and nursing staff as requiring more staff time and/or expertise and/or medical equipment than is available in homes for the aged were assessed. Only 27 out of 2,447 (1.1%) extremely infirm aged persons resident in 93 homes for the aged would, in the opinion of institutional staff, benefit by admission to a long-term care hospital catering for chronically ill. The conditions affecting these residents are described and recommendations relating to their management made.

Aged↗
PubMed1991

Frail aged persons residing in South African homes for the aged who require hospitalisation. Part II. Rural areas.

The numbers and characteristics of white residents identified by medical and nursing staff to require more staff time and/or expertise and/or medical equipment than was available in rural homes for the aged in the Orange Free State were assessed. In the opinion of institution staff, 12.6% of extremely infirm aged persons would benefit by admission to a hospital catering for the chronically ill. The conditions affecting these residents are described and recommendations relating to their management are made.

Aged↗