Biomedical subjects

N Wray

Publications and source records attributed to N Wray.

11 recordsLinked to original sources

PubMed2001

Multi-professional staff development programme for PAMs.

A unique, accredited, multi-professional education programme for junior staff in professions allied to medicine (PAMs) developed by Durham and Teesside Education and Training Consortium in collaboration with local trusts and social services is described. Designed to ensure competence to practice in line with clinical governance, it aims to strengthen multi-professional working practice through a greater understanding of roles and of the way the national health service (NHS) works. It enables staff to analyse their own learning needs and to employ self-directed learning skills for life-long learning. Using problem-based learning, it uses real clinical cases as triggers to promote critical evaluation and reasoning and the development of multi-professional care pathways.

Allied Health Personnel↗

PubMed1999

Population density and childhood leukaemia: results of the EUROCLUS Study.

The EUROCLUS study assembled incidence data for 13,551 cases of childhood leukaemia (CL) diagnosed between 1980 and 1989 in 17 countries (or regions of countries). These were referenced by location at diagnosis to small census areas of which there were 25,723 in the study area. Population counts, surface area and, hence, population density were available for all these small areas. Previous analyses have shown limited extra-Poisson variation (EPV) of case counts within small areas; this is most pronounced in areas of intermediate population density (150-499 persons/km2). In this study, the data set was examined in more detail for evidence that variations in incidence and EPV of CL are associated with population density. Incidence showed a curvilinear association with population density and was highest in areas which were somewhat more densely populated (500-750 persons/km2), where the incidence rate ratio relative to areas having > or = 1000 persons/km2 was 1.16 (95% confidence interval 1.07-1.26) and the P value for quadratic trend across eight strata of population density was 0.02. Incidence in these areas is uniformly elevated and showed no evidence of heterogeneity (i.e. EPV). Statistically significant evidence of EPV was evident amongst some of the areas previously classified as intermediate density areas (specifically, those with a density of 250-499 persons/km2, P < 0.001 for CL). These results were interpreted in terms of the current aetiological hypotheses for CL which propose that exposure to localised epidemics of one or more common infectious agent may contribute to the development of leukaemia. They suggest that such epidemics arise regularly in moderately densely populated areas and also sporadically in areas which are somewhat less densely populated. Although other interpretations are possible, these results may assist in the identification of characteristics which infectious agents must possess if direct or indirect causes of CL.

Child↗

PubMed1998

Spatial clustering of childhood leukaemia: summary results from the EUROCLUS project.

The interpretation of reports of clusters of childhood leukaemia is difficult, first because little is known about the causes of the disease, and second because there is insufficient information on whether cases show a generalized tendency to cluster geographically. The EUROCLUS project is a European collaborative study whose primary objective is to determine whether the residence locations of cases at diagnosis show a general tendency towards spatial clustering. The second objective is to interpret any patterns observed and, in particular, to see if clustering can be explained in terms of either infectious agents or environmental hazards as aetiological agents. The spatial distribution of 13351 cases of childhood leukaemia diagnosed in 17 countries between 1980 and 1989 has been analysed using the Potthoff-Whittinghill method. The overall results show statistically significant evidence of clustering of total childhood leukaemia within small census areas (P=0.03) but the magnitude of the clustering is small (extra-Poisson component of variance (%) = 1.7 with 90% confidence interval 0.2-3.1). The clustering is most marked in areas that have intermediate population density (150-499 persons km[-2]). It cannot be attributed to any specific age group at diagnosis or cell type and involves spatial aggregation of cases of different ages and cell types. The results indicate that intense clusters are a rare phenomenon that merit careful investigation, although aetiological insights are more likely to come from investigation of large numbers of cases. We present a method for detecting clustering that is simple and readily available to cancer registries and similar groups.

Adolescent↗

PubMed1997

Dimensions of quality of life expressed by men treated for metastatic prostate cancer.

Men who pursue active treatment for metastatic prostate cancer face a choice between medical or surgical castration. While both alternatives have documented side-effects (e.g. loss of libido, breast enlargement and tenderness, hot flashes, and nausea), their psychosocial impacts are not well understood. As part of a study of patients' treatment decision making, we have sought to construct a patient-based measure of the salient disease and treatment-related qualities of life experienced by these men subsequent to treatment. Focus groups (15 with patients, two with wives) were used to develop candidate Likert scale questionnaire items representing quality of life issues that patients said were important. These items were combined with assessments of symptoms, comorbidity, and generic measures of functional status and well-being in a mail survey of patients treated at the Houston VAMC and two other Houston hospitals (n = 201, response rate = 63%). Psychometric analyses (principal components and multitrait scaling) were used to identify distinct dimensions of life quality; correlations with generic measures, and symptom reports were used in validation analyses. Qualitative analyses of focus group data identified three major domains of life quality: self-perceptions, anxiety about the effects of treatment, and concern with the process of decision making and treatment. Psychometric analyses identified nine reliable and valid indicators of prostate cancer-related quality of life: body image, sexual problems, spouse affection, spouse worry, masculinity, cancer-related self-image, cancer distress, cancer acceptance, and regret of treatment decision. Internal consistency (alpha) ranged form 0.71 to 0.90. Correlations with reference scales (e.g. MOS Mental Health Index, Profile of Mood States) and symptom status supported concurrent validity. Prostate cancer patients perceive a number of important psychosocial consequences of their treatment. These consequences are represented by nine scales comprising a brief (35 items) disease and treatment sensitive health-related quality of life instrument, which we will use in monitoring the outcomes of patients' treatment choices.

Adaptation, Psychological↗

PubMed1997

Aggregation of childhood leukemia in geographic areas of Greece.

A total of 872 children aged up to 14 years, who were diagnosed with leukemia in Greece during the decade 1980-89, were allocated by place of residence to the 601 administrative districts of the country. Evaluation of spatial clustering was done using the Potthoff-Whittinghill method, which validly assesses heterogeneity of leukemia risk among districts with variable expected numbers of cases. There was highly significant evidence for spatial clustering occurring particularly among children living in urban and, to a lesser extent, semi-urban areas. The evidence was stronger for children younger than 10 years old, applied also to children in different five-year age groups, and persisted when cases of acute lymphoblastic leukemia were analyzed separately. These findings provide support to the hypothesis that localized environmental exposures could contribute to the etiology of childhood leukemia, but they cannot distinguish between exposures of physical or chemical nature, nor can they exclude socially conditioned patterns of exposure to infectious agents.

Adolescent↗

PubMed1991

The impact of economic considerations on clinical decisionmaking: the case of thrombolytic therapy.

This study examines the intravenous use of two thrombolytic agents [streptokinase (SK) and tissue plasminogen activator (tPA)] in the acute phase of myocardial infarction (MI). These two agents have very different costs and offer an excellent opportunity to study both the impact of economic factors on clinical decisionmaking and the potential for cost savings by limiting the use of expensive new therapeutic agents. A nationwide survey of the 5,792 acute care general hospitals listed in the American Hospital Association's 1988 data file was responded to by 2,651 hospitals (46%) and revealed that 2,384 of these responding hospitals (90%) were using thrombolytic therapy. For 2,200 of these 2,384 hospitals (92%), the respondent was a physician who primarily used one of the two drugs. Eight hundred eighty-six of these 2,200 physicians (40%) primarily used SK while 1,314 (60%) primarily used tPA. SK users were more concentrated in federal public hospitals (69% used SK) than in nonfederal public hospitals (47% used SK), and were least concentrated in private hospitals (36% used SK). There was no difference between the rate of SK vs tPA use in investor-owned and not-for-profit private hospitals. SK users most often (62%) cited various economic factors as the reason for their choice. The users of tPA primarily (73%) cited clinical preferability as the reason for their choice even though trials are still ongoing to see which drug is preferable. Several multivariate analyses shed light upon the association between choice of thrombolytic agent and various additional physician and hospital characteristics. These data clearly indicate that while new therapies are rapidly implemented by the medical community, considerations of cost have a substantial impact upon the pattern of implementation and reflect a desire to implement cost savings in the use of new drugs.

Data Collection↗

PubMed1990

Acute and chronic effects of propranolol on extinction of rewarded running in the rat.

Three experiments examined the effect of propranolol injected IP on a series of 16 extinction trials at 24-hour intertrial intervals after continuously rewarded running. In Experiment I, propranolol (1, 5 or 10 mg/kg) was injected, in different groups, shortly before or shortly after each extinction trial, but without effect. In Experiment II, the same doses were injected daily for 18 days preceding extinction, to allow longer for any long-term drug effect to accumulate. Propranolol (1 mg/kg) facilitated extinction. In Experiment III, a single dose (7.5 mg/kg) was injected before or after extinction trials as in Experiment I; the acute effect was to impair extinction. These results are consistent with previous findings in the Skinner box that propranolol has an acute disinhibitory effect on nonrewarded responses and a long-term inhibitory one. These effects have different dose-response relationships.

Animals↗

PubMed1988

Withholding medical treatment from the severely demented patient. Decisional processes and cost implications.

We performed an observational study to determine the prevalence of severe dementia in a general medicine unit, the categories of acute medical care provided to these patients, the process by which treatment decisions are made, and their cost implications. The prevalence of severe dementia was 4.4%. The patients from whom some form of acute medical care was withheld (26 [45.6%] of 57) were more severely ill at admission and had a mortality rate five times higher than those who received full care. Physicians cited family wishes in 75.9% of the decisions to limit care but in only 10.9% of the decisions to give full care. The only differences in charges incurred were due to differential mortality rates in individuals from whom care was withheld. We recommend that hospitals develop and implement protocols for decision making in the care of the severely demented to promote open discussions among providers and families and to increase family contributions to decision making. We believe that the extension of this consultative approach to decisions involving severely demented patients may have the virtue of combining more humane care with more cost-effective care.

Acute Disease↗

PubMed1979

Aryl hydrocarbon hydroxylase activity in pulmonary alveolar macrophages and lymphocytes from lung cancer and noncancer patients: a correlation with family histories of cancer.

Aryl hydrocarbon hydroxylase (AHH) activity was measured in pulmonary alveolar macrophages (PAMs) and peripheral blood lymphocytes from cigarette smokers with and without primary lung cancer. Frequency distribution analysis of AHH induction ratios for the two groups revealed an increased number of individuals in the lung cancer patient group with high lymphocyte induction values (P less than 0.05). A similar increase was not shown for high-PAM AHH values in lung cancer patients (P greater than 0.2). When individual PAM and lymphocyte AHH values were compared between noncancer and lung cancer patients, a positive correlation was observed for noncancer patients (r=0.195, P less than 0.001), but no correlation of these values was noted for lung cancer patients. The lung cancer patients were divided into three subgroups of patients showing (I) high PAM and low lymphocyte AHH levels, (II) low PAM and low lymphocyte AHH levels, and (III) low PAM and high lymphocyte AHH levels. When the incidence of family history of cancer was compared for these subgroups, no family cancer history was recorded for persons in subgroup II; however, individuals in subgroups I and III presented family cancer history incidence of 9.5% and 39.3%, respectively. Patients in group III averaged 6 years younger than those in group I. These data suggest that familial factors may be identified among lung cancer patients and that these factors appear to associate as either a cause of an effect with the capacity of pulmonary alveolar macrophages and lymphocytes to be induced for AHH. The data support the hypothesis that high AHH values may be characteristic of lung cancer patients but show that enzyme values determined from a single tissue, either PAMs or lymphocytes, may not be appropriate for showing whether high AHH inducibility is correlated with lung cancer.

Aryl Hydrocarbon Hydroxylases↗

PubMed1979

Phagocytosis of asbestos fibers by human pulmonary alveolar macrophages.

Human pulmonary alveolar macrophages (PAMs) were cultured for 24--72 h with varying concentrations (0--300 microgram/ml) of amosite asbestos (AS). At lower AS concentrations, (less than 100 microgram/ml) no decrease in cell viability occurred during the first 24 h of culture. Significant cytotoxicity (P less than 0.005 in all instances) was observed, however, following incubation for 24 h with higher AS concentrations (greater than 100 microgram/ml). Even following incubation with lower concentrations of AS, significant cytotoxicity (P less than 0.006 in all instances) was observed after 48 or 72 h of culture. Scanning electron microscopy (SEM) clearly illustrates the various stages of AS phagocytosis by PAMs. SEM also documented morphological changes in PAMs following AS exposure. These included increased zeiosis and the appearance of a fibrous-like material on the surface of AS fibers following initial contact with the PAM cytoplasmic membrane. Further study of the biological interactions between AS and human cells, such as PAMs, might provide valuable information regarding the etiology of AS-related lung disorders.

Adult↗

PubMed1978

A human plasma component that binds benzo(a)pyrene.

A component capable of binding benzo(a)pyrene was measured in plasma from cigarette smokers and nonsmokers. This plasma fraction was found to have a high specificity of binding to benzo(a)pyrene, bound benzanthracene competitively with benzo(a)pyrene, and was positively correlated (r = 0.861, p less than 0.001) with the capacity of the individual subject's lymphocytes to be induced for AHH activity in culture. An inverse correlation (r = -0.957, p less than 0.001) between the presence of the plasma component in lung cancer patients and the capacity of lung cancer patients' lymphocytes to be induced in culture is unexplained at this time. A benzo(a)pyrene-binding fraction was not found in induced or uninduced cultured lymphocytes from smokers or nonsmokers, or in homogenates of lung excisional tissue from smokers with or without primary lung cancer.

Aryl Hydrocarbon Hydroxylases↗