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Biomedical subjects

S Lewis

Publications and source records attributed to S Lewis.

At least 253 records · Page 14Linked to original sources
PubMed1995

Magnetic resonance imaging in myelodysplastic syndromes.

In this study we used magnetic resonance imaging (MRI) to examine the axial bone marrow of 11 patients with myelodysplastic syndromes (MDS). T1 weighted images showed a reduction in signal intensity in all patients. The degree of reduction in signal intensity correlated with bone marrow cellularity rather than percentage blasts or French-American-British Co-operative group (FAB) classification. T2 weighted images showed an increase in signal intensity in 10 out of 11 patients; however, reliable grading was not possible using this sequence. Both T1 and T2 weighted images indicated a homogeneous pattern of disease within the axial skeleton in MDS. We have also shown that iron deposition in multiply transfused patients is a significant factor influencing signal reduction. The results of this study suggest that MRI may have a diagnostic role in MDS but is unlikely to be of value in staging.

Adult↗
PubMed1995

Anterior single-tooth implant restorations.

The application of implant dentistry to the treatment of partial edentulism has necessitated the development of new components and techniques. This article reviews the various systems and techniques used to fabricate successful anterior single-tooth implant restorations. Placement techniques for nonsegmented, screw-retained abutments; segmented, screw-retained abutments; and segmented, cement-retained abutments are illustrated.

Cementation↗
PubMed1995

Double trouble.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed1994

The 5q-syndrome.

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Aged↗
PubMed1994

The self reported prevalence of asthma symptoms amongst adult New Zealanders.

AIMS: To examine the prevalence of asthma symptoms in a random population sample of New Zealand adults aged 20-44 years drawn from the general and Maori electoral rolls as phase I of an international study of asthma prevalence. METHODS: Subjects aged 20-44 years in Auckland, Hawkes Bay, Wellington and Christchurch, were selected randomly from the electoral rolls and sent a one page screening questionnaire, asking about respiratory symptoms, asthma attacks and asthma treatment. They were also asked to record their ethnic affiliation. Nonresponders were subsequently sent two written reminders followed by a telephone questionnaire where possible. RESULTS: A response rate of 84% was achieved. The study found a high prevalence of asthma symptoms, with 26% reporting wheezing in the last year, 8% experiencing an attack of asthma in the last year and 9% currently using asthma medication. Females were more likely to have had wheezing in the last year (26.6%) and be on treatment for asthma (9.8%) compared with males (24.7% and 7.5% respectively). Small regional differences were found with more reported symptoms and asthma treatment in Wellington and Christchurch, compared with Auckland and Hawkes Bay. Maori were more frequently symptomatic (35.2%) than nonPolynesian (24.8%) but were no more likely to report an attack of asthma (Maori 9.0%, nonPolynesian 7.7%) or be currently receiving asthma treatment (Maori 10.0%, nonPolynesian 8.6%). Asthma symptoms tended to decline with age in non Maori but increased with age in Maori. Adjustment of prevalence rates by two independent methods suggests that nonresponse bias has not significantly inflated these rates. CONCLUSIONS: The symptoms of asthma and their treatment are common in young New Zealanders, affecting one in three Maori and one in four nonMaori. One in ten of this adult population currently receive asthma treatment.

Adult↗
PubMed1994

The influence of increased health care costs on general practitioner consultations and prescription collection.

AIM: Increased health service charges have led to concern that some patients may be unable to meet these costs, which could compromise their care. Increased costs may affect general practitioner attendance, and/or the collection of a prescription. This study examines both of these factors. METHODS: Between 18 August and 14 September 1992, questionnaires were sent to the consenting patients of 19 general practitioners from the Hutt Valley requesting information regarding the general practice (GP) visit and the prescription. The information included the reason for the GP visit, whether there was any delay and its duration, the reason for any delay, the cost of the visit and whether a prescription was received. Data regarding the prescription included the cost and whether all, some, or none of the items were uplifted, and whether the patient had a community service card. RESULTS: 489 (86%) returned completed questionnaires and 426 received a prescription. Of these, 164 were group 1 community service card holders; one was a group 2 community service card holder; 186 were group 3; 59 did not specify their group; 18 had a chronic-user card. Forty percent (194 patients), delayed going to their doctor, 118 by more than 3 days. The most common reasons for delay were hope that their condition may improve spontaneously and the cost of the consultation or prescription. Possession of a community service card was a significant factor in delay with group 3 (high wage earners) more likely to delay than group 1 (p < 0.0005). Only two patients did not present their prescription. Ninety-three percent of those receiving a prescription presented for dispensing within 24 hours. Ninety-two percent of patients paid for all their prescription items. CONCLUSIONS: Delay in obtaining treatment is common and occurs primarily at the general practitioner consultation. It primarily affects those individuals who were classified as group 3, the group that has taken the burden of recent health service charges increases.

Adolescent↗
PubMed1994

Dietary magnesium, lung function, wheezing, and airway hyperreactivity in a random adult population sample.

Magnesium is involved in a wide range of biological activities, including some that may protect against the development of asthma and chronic airflow obstruction. We tested the hypothesis that high dietary magnesium intake is associated with better lung function, and a reduced risk of airway hyper-reactivity and wheezing in a random sample of adults. In 2633 adults aged 18-70 sampled from the electoral register of an administrative area of Nottingham, UK, we measured dietary magnesium intake by semiquantitative food-frequency questionnaire, lung function as the 1-sec forced expiratory volume (FEV1), and atopy as the mean skin-prick test response to three common environmental allergens. We measured airway reactivity to methacholine in 2415 individuals, defining hyper-reactivity as a 20% fall in FEV1 after a cumulative dose of 12.25 mumol or less. Mean (SD) daily intake of magnesium was 380 (114) mg/day. After adjusting for age, sex, and height, and for the effects of atopy and smoking, a 100 mg/day higher magnesium intake was associated with a 27.7 (95% CI, 11.9-43.5) mL higher FEV1, and a reduction in the relative odds of hyper-reactivity by a ratio of 0.82 (0.72-0.93). The same incremental difference in magnesium intake was also associated with a reduction in the odds of self-reported wheeze within the past 12 months, adjusted for age, sex, smoking, atopy, and kilojoule intake, by a ratio of 0.85 (0.76-0.95). Dietary magnesium intake is independently related to lung function and the occurrence of airway hyper-reactivity and self-reported wheezing in the general population. Low magnesium intake may therefore be involved in the aetiology of asthma and chronic obstructive airways disease.

Adult↗
PubMed1994

Amplification of DNA of Mycobacterium tuberculosis from peripheral blood of patients with pulmonary tuberculosis.

Sputum examination for rapid diagnosis of pulmonary tuberculosis is not always satisfactory. We examined peripheral blood with the polymerase chain reaction (PCR). Blood samples were collected from 8 consecutive patients with suspected pulmonary tuberculosis and from 18 healthy controls, half of whom were tuberculin skin-test positive. All 8 patients had evidence of circulating Mycobacterium tuberculosis DNA in the lymphocyte fraction of peripheral blood, and positive sputum cultures indicating active pulmonary tuberculosis. None of the healthy controls had positive PCR results. This PCR technique may prove useful for the rapid diagnosis of tuberculosis.

DNA, Bacterial↗
PubMed1994

Tacrine alters the secretion of the beta-amyloid precursor protein in cell lines.

The characteristic features of Alzheimer's disease (AD) include a high density of beta-amyloid-containing plaques in the cerebral cortex and the loss of basal forebrain cholinergic neurons. Amyloid beta-protein (A beta, Mr. approximately 4.5 kDa) is derived from a family of large (Mr. approximately 110-140 kDa) beta-amyloid precursor proteins (APP) which are integral membrane glycoproteins consisting of a large extracytoplasmic domain, a transmembrane domain, and a short cytoplasmic tail. Secreted derivatives of APP lacking the cytoplasmic tail, transmembrane domain, and a small portion of the extracellular domain are generated by the proteolytic processing of full length APP by a family of proteolytic enzymes known as APP secretases. Using cell cultures, we investigated the possibility that APP processing can be regulated by a centrally active cholinesterase inhibitor, tacrine, which has recently been shown to improve memory and cognitive functions in patients with AD. We analyzed the level of APP in glial, fibroblast, pheochromocytoma (PC12), and neuroblastoma cells by immunoblotting cell lysates and conditioned media. Normal levels of secretion of soluble APP derivatives by cells into conditioned media were severely inhibited by treating cells with tacrine. A similar decrease after treatment with tacrine was observed when neuroblastoma and PC12 cells were pretreated with either growth factors, phorbol ester, or retinoic acid. To determine whether the effect of tacrine on APP levels was specific or a more general phenomenon affecting other proteins, we measured the level of heat shock protein-70 (HSP-70) and another secretory protein, protease nexin-1 (PN-1). Tacrine treatment did not alter the level of HSP-70 in cell extracts and tacrine affected mildly the secretion of PN-1. Thus, the processing of HSP and PN-1, unlike APP, was not severely affected by treating cells with tacrine. Our results suggest that tacrine may inhibit an acetylcholinesterase-associated proteolytic activity involved in the secretion of APP, which results in less secretion of soluble APP into the conditioned media from tacrine treated cells. These results demonstrate that tacrine regulates APP secretion in cell cultures and suggest the possibility that tacrine therapy of Alzheimer's disease may, in the longer term, have effects on the process of A beta deposition.

Amyloid beta-Protein Precursor↗
PubMed1994

Molecular mapping of uncharacteristically small 5q deletions in two patients with the 5q- syndrome: delineation of the critical region on 5q and identification of a 5q- breakpoint.

Molecular mapping techniques have defined the region of gene loss in two patients with the 5q- syndrome and uncharacteristically small 5q deletions (5q31-q33). The allelic loss of 10 genes localized to 5q23-qter (centromere-CSF2-EGR1-FGFA-GRL-ADRB2-CS F1R-SPARC-GLUH1-NKSF1-FLT4-telomere) was investigated in peripheral blood cell fractions. Gene dosage experiments demonstrated that CSF2, EGR1, NKSF1, and FLT4 were retained on the 5q- chromosome in both patients and that FGFA was retained in one patient, thus placing these genes outside the critical region. GRL, ADRB2, CSF1R, SPARC, and GLUH1 were shown to be deleted in both patients. The proximal breakpoint is localized between EGR1 and FGFA in one patient and between FGFA and ADRB2 in the other, and the distal breakpoint is localized between GLUH1 and NKSF1 in both patients. Pulsed-field gel electrophoresis was used to map the 5q deletion breakpoints, and breakpoint-specific fragments were detected with FGFA in the granulocyte but not the lymphocyte fraction of one patient. This study has established the critical region of gene loss of the 5q- chromosome in the 5q- syndrome, giving the location for a putative tumor-suppressor gene in the 5.6-Mb region between FGFA and NKSF1.

Adult↗
PubMed1994

Cannabis and acute psychosis.

The Present State Examination was used to assess the psychopathology of 23 psychotic patients who were cannabis positive on urinary screening, and 46 matched drug-free controls. Cases and controls were indistinguishable in terms of psychopathology, DSMIII diagnoses, onset of recent illness, the proportion of first admissions, ethnicity, and socio-economic class, differing only in their histories of substance use. These data suggest that psychosis which develops or recurs in the context of cannabis use does not have a characteristic psychopathology or mode of onset, and is not restricted to a particular ethnic or socio-demographic group. There is thus little evidence to support the validity of 'cannabis psychosis' as a diagnostic entity.

Acute Disease↗
PubMed1994

The influence of life events on the subsequent course of psychotic illness. A prospective follow-up of the Camberwell Collaborative Psychosis Study.

Fifty-nine psychotic patients with acute onset of illness, who had been interviewed about their experience of stressful life events before the episode, were followed up for an average of 42 months. Thirty patients (51%) had experienced a stressful life event in the 3 months immediately before onset (EV+), 29 had not (EV-). In patients with an RDC diagnosis of affective disorder or unspecified functional psychosis, the presence of stressful life events was associated subsequently with milder symptom severity, less time spent in hospital, more treatment for depressive symptoms and less for psychotic symptoms. In schizophrenia, differences were less apparent, but patients with event associated episodes had less need of anti-psychotic maintenance medication over the follow-up period and tended to have spent more time in complete remission. EV+ schizophrenic subjects also had higher morbid risk for schizophrenia in their first degree relatives, and tended to be female and to have less typical symptoms than EV- schizophrenic patients.

Adult↗
PubMed1994

Psychosocial factors and chronic fatigue syndrome.

This study investigated the number and severity of life events, Type A behaviour, coping strategies and social support differences between chronic fatigue and irritable bowel syndrome patients prior to illness and between these groups and healthy controls. Although few differences were found between the groups for life events, a number of interesting results emerged with regard to different aspects of Type A behaviour, various coping strategies and social support. These findings are discussed with respect to existing research in the field.

Adaptation, Psychological↗
PubMed1994

Can oncologists detect distress in their out-patients and how satisfied are they with their performance during bad news consultations?

Recognition of psychological distress in patients with cancer, some of which can be ameliorated with appropriate intervention, is a crucial aspect of patient care. Previous studies, with the exception of one, indicate that oncologists often fail to detect general distress and do not identify those patients with significant psychological disorder. As approximately 25-30% of patients experience anxiety and/or depression severe enough to merit psychological intervention, this is a serious problem. This study assessed the ability of five oncologists to recognise distress in newly referred out-patients who were receiving bad news. Self-report measures of the oncologists' satisfaction with their performance during the bad news interviews were also collected. Each patient had two clinical interviews in which information concerning diagnosis and treatment were given. Prior to each interview patients reported their own levels of distress by completing two self-report questionnaires. These were correlated with the ratings of distress and satisfaction made by each clinician on a visual analogue scale after each interview. Only one oncologist's ratings consistently correlated with patients' self-reported scores. The clinicians tended to under-rate the distress in their patients and were mostly satisfied with their performances during each interview. The ability to detect distress varied between each clinician and confirmed the conclusions of past studies that oncologists would benefit from up-grading their psychological assessment skills.

Adult↗
PubMed1994

Nurses' knowledge of and attitudes towards sexuality and the relationship of these with nursing practice.

Issues concerning sex and sexuality are relevant to nursing practice. The objective of this study was to determine the relationship between knowledge of and attitude towards sexuality, and nursing practice. Nursing practice in this case was defined as the discussion of sexuality with the patient, with particular reference to taking a sexual history on admission to the ward. A multi-choice questionnaire with sections establishing demographic details and nursing practice, and including the Sex, Knowledge and Attitude Test (SKAT), was administered to 357 registered general nurses (RGNs). Results show a relationship between knowledge and attitude but no relationship between either of these and the nursing practice scale. However, a slight but significant correlation between receiving teaching about sexual history taking and questioning patients about sexuality on admission suggests that nursing practice and knowledge are weakly related. There is evidence that factors other than those within the scope of this study influence all three independent variables, and these are discussed. The implications of the study suggest the need for an improvement in nurse education regarding sexuality at all stages of training.

Adult↗