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Biomedical subjects

D Gray

Publications and source records attributed to D Gray.

At least 91 records · Page 5Linked to original sources
PubMed1999

Moving beyond information: evaluation of a nutrition education tool based on a theoretical model.

OBJECTIVE: This study investigated the relative effectiveness of a nutrition education brochure based on a theoretical model versus a more traditional information-based brochure in getting subjects to accurately assess daily calcium intake, make a plan to increase intake if needed, and to implement the plan. DESIGN: A randomized trial involving 216 women between the ages of 19-49y. Subjects were randomly assigned to a group which received educational materials containing an interactive brochure designed using the Motivation Generating model (Calcium CalculatorS), or to a group which received a calcium information brochure (An Appetite for Good Health). Within a two week period the women were contacted by telephone to assess use of materials, calcium intake assessment information, and plans for dietary change. SETTING: Subjects were recruited at five fitness centres in the Vancouver area. The research was conducted by the Institute of Health Promotion Research at the University of British Columbia. RESULTS: Results indicated significantly greater numbers of subjects conducting self- assessment and increased group accuracy for calcium intake assessment in subjects using the interactive brochure. CONCLUSION: Use of a theoretical model designed to create behaviour change such as the Motivation Generating Model can increase specific behaviours which may lead to improvements in dietary consumption.

Adult↗
PubMed1999

Influence of ambulance crew's length of experience on the outcome of out-of-hospital cardiac arrest.

AIMS: To investigate whether an ambulance crew's length of experience affected the outcome of out-of-hospital cardiac arrest. METHODS AND RESULTS: This was a population-based, retrospective observational study of attempted resuscitations in 1547 consecutive arrests of cardiac aetiology by Nottinghamshire Emergency Ambulance Service crew. One thousand and seventy-one patients were managed by either a paramedic or a technician crew without assistance from other trained individuals at the scene of arrest. Overall, the chances of a patient surviving to be discharged from hospital alive did not appear to be affected by the paramedic's length of experience (among survivors, 18 months experience vs non-survivors 16 months experience, P = 0.347) but there appears to be a trend in the effect of a technician's length of experience on survival (among survivors, 60 months experience vs non-survivors 28 months experience, P = 0.075). However, when a technician had 4 years of experience or more and a paramedic 1 year's experience, survival rates did improve. Logistic regression analysis, adjusted for factors known to influence outcome, revealed that chances of survival increased once technicians had over 4 years of experience after qualification (odds ratio 2.71, 95% CI 1.17 to 6.32, P = 0.02) and paramedics after just 1 year of experience (odds ratio 2.68, 95% CI 1.05 to 6.82, P = 0.04). CONCLUSIONS: Survival from out-of-hospital cardiac arrest varies with the type of ambulance crew and length of experience after qualification. Experience in the field seems important as paramedics achieve better survival rates after just 1 year's experience, while technicians need to have more than 4 years' experience to improve survival.

Ambulances↗
PubMed1999

Statin prescribing in Nottingham general practices: a cross-sectional study.

BACKGROUND: The aim of the study was to determine the effect of deprivation on variations in statin prescribing in Nottingham general practices. Deprivation is used as a measure of population cardiovascular morbidity and need for statin treatment. The setting was all 118 general practices in contract with Nottingham Health Authority. METHODS: A cross-sectional study was undertaken. Statin prescribing in general practice during 1996 was related to indices of practice deprivation based on enumeration district (ED) level data from the 1991 Census. The relationship between statin prescribing per 1000 patients aged 35-69 and practice deprivation (measured both as Townsend score and as Jarman UPA(8) score) with additional adjustment for practice characteristics (number of partners, training status, total list size, fundholding status) cardiovascular prescribing costs net of lipid prescribing and hospital activity (total and medical admissions and new general practitioner total and medical out-patient referrals) for each practice. RESULTS: The prescription of statins during 1996 varied between nil and 14.1 'statin-years' of prescribing per 1000 patients aged 35-69. There was a significant inverse relationship between the rate of statin prescribing and the level of deprivation of that practice (p < 0.0001). Deprivation, as measured by Townsend index, accounted for 13 per cent of the total variability in statin prescribing, which rose to 19 per cent after adjustment. The prescribing of other lipid lowering agents of the fibrate class was positively associated with statin prescribing (p=0.001) and this association persisted after adjusting for deprivation. None of the other practice characteristics were found to be significantly associated with rates of statin prescribing. CONCLUSIONS: General practices with high deprivation indices serve more deprived populations with a higher prevalence of cardiovascular disease, and may be assumed to have a greater need for statins. Despite this, practices with higher deprivation indices prescribed fewer statins to their patients than less deprived practices. It was not possible to identify whether the more deprived general practices had successfully identified at risk individuals but it is likely that special efforts are needed to increase the uptake of effective health care in their patients.

Adult↗
PubMed1999

Interleukin-10 gene-deficient mice develop a primary intestinal permeability defect in response to enteric microflora.

The normal intestinal epithelium provides a barrier relatively impermeable to luminal constituents. However, patients with inflammatory bowel disease experience enhanced intestinal permeability that correlates with the degree of injury. IL-10 gene-deficient mice were studied to determine whether increased intestinal permeability occurs as a primary defect before the onset of mucosal inflammation or is secondary to mucosal injury. At 2 weeks of age, IL-10 gene-deficient mice show an increase in ileal and colonic permeability in the absence of any histological injury. This primary permeability defect is associated with increased mucosal secretion of interferon-gamma and tumor necrosis factor-alpha, and does not involve an increase in nitric oxide synthase activity. Colonic permeability remains elevated as inflammation progresses, while ileal permeability normalizes by 6 weeks of age. IL-10 gene-deficient mice raised under germ-free conditions have no inflammation, and demonstrate normal permeability and cytokine levels. This data suggests that the intestinal permeability defect in IL-10 gene-deficient mice occurs due to a dysregulated immune response to normal enteric microflora and, furthermore, this permeability defect exists prior to the development of mucosal inflammation.

Animals↗
PubMed1999

The Northern Territory's cask wine levy: health and taxation policy implications.

OBJECTIVE: To examine the effect of the application, and removal, in the Northern Territory of a levy on the sale of cask wine--a beverage shown to contribute disproportionately to alcohol-related harm. METHOD: Using data on licensee purchases of alcoholic beverages and ABS population data, estimates were made of per capita consumption of pure alcohol by beverage type. Time series variables were analysed using multiple linear regression analysis. RESULTS: Prior to the introduction of the levy, quarterly per capita consumption of cask wine among persons aged > or = 15 years was 0.73 litres. During the levy period, this fell to 0.49 litres and following removal of the levy rose to 0.58 litres. Imposition of the levy had no significant effect on the consumption of other beverages. CONCLUSIONS: Taxation is an effective means of reducing excessive alcohol consumption and related harm. IMPLICATIONS: In the interests of public health, support should be given to the introduction of a tiered tax based on alcohol content.

Adolescent↗
PubMed1999

Resuscitation from out-of-hospital cardiac arrest: is survival dependent on who is available at the scene?

OBJECTIVE: To determine whether survival from out-of-hospital cardiac arrest is influenced by the on-scene availability of different grades of ambulance personnel and other health professionals. DESIGN: Population based, retrospective, observational study. SETTING: County of Nottinghamshire with a population of one million. SUBJECTS: All 2094 patients who had resuscitation attempted by Nottinghamshire Ambulance Service crew from 1991 to 1994; study of 1547 patients whose arrest were of cardiac aetiology. MAIN OUTCOME MEASURES: Survival to hospital admission and survival to hospital discharge. RESULTS: Overall survival from out-of-hospital cardiac arrest remains poor: 221 patients (14.3%) survived to reach hospital alive and only 94 (6.1%) survived to be discharged from hospital. Multivariate logistic regression analysis showed that the chances of those resuscitated by technician crew reaching hospital alive were poor but were greater when paramedic crew were either called to assist technicians or dealt with the arrest themselves (odds ratio 6.9 (95% confidence interval 3.92 to 26.61)). Compared to technician crew, survival to hospital discharge was only significantly improved with paramedic crew (3.55 (1.62 to 7.79)) and further improved when paramedics were assisted by either a health professional (9.91 (3.12 to 26.61)) or a medical practitioner (20.88 (6.72 to 64.94)). CONCLUSIONS: Survival from out-of-hospital cardiac arrest remains poor despite attendance at the scene of the arrest by ambulance crew and other health professionals. Patients resuscitated by a paramedic from out-of-hospital cardiac arrest caused by cardiac disease were more likely to survive to hospital discharge than when resuscitation was provided by an ambulance technician. Resuscitation by a paramedic assisted by a medical practitioner offers a patient the best chances of surviving the event.

Aged↗
PubMed1999

Quality of life four years after acute myocardial infarction: short form 36 scores compared with a normal population.

OBJECTIVES: To assess the impact of myocardial infarction on quality of life in four year survivors compared to data from "community norms", and to determine factors associated with a poor quality of life. DESIGN: Cohort study based on the Nottingham heart attack register. SETTING: Two district general hospitals serving a defined urban/rural population. SUBJECTS: All patients admitted with acute myocardial infarction during 1992 and alive at a median of four years. MAIN OUTCOME MEASURES: Short form 36 (SF 36) domain and overall scores. RESULTS: Of 900 patients with an acute myocardial infarction in 1992, there were 476 patients alive and capable of responding to a questionnaire in 1997. The response rate was 424 (89. 1%). Compared to age and sex adjusted normative data, patients aged under 65 years exhibited impairment in all eight domains, the largest differences being in physical functioning (mean difference 20 points), role physical (mean difference 23 points), and general health (mean difference 19 points). In patients over 65 years mean domain scores were similar to community norms. Multiple regression analysis revealed that impaired quality of life was closely associated with inability to return to work through ill health, a need for coronary revascularisation, the use of anxiolytics, hypnotics or inhalers, the need for two or more angina drugs, a frequency of chest pain one or more times per week, and a Rose dyspnoea score of >/= 2. CONCLUSIONS: The SF 36 provides valuable additional information for the practising clinician. Compared to community norms the greatest impact on quality of life is seen in patients of working age. Impaired quality of life was reported by patients unfit for work, those with angina and dyspnoea, patients with coexistent lung disease, and those with anxiety and sleep disturbances. Improving quality of life after myocardial infarction remains a challenge for physicians.

Aged↗
PubMed1999

Relevance of clinical trial results in myocardial infarction to medical practice: comparison of four year outcome in participants of a thrombolytic trial, patients receiving routine thrombolysis, and those deemed ineligible for thrombolysis.

OBJECTIVE: To assess the medium to long term outcome of patients ineligible for thrombolysis compared to those enrolled in a clinical trial of thrombolysis and patients receiving non-trial thrombolysis. DESIGN: Cohort study based on the Nottingham heart attack register. SETTING: Two district general hospitals serving a defined urban/rural population. SUBJECTS: All patients admitted with a confirmed acute myocardial infarction during 1992 categorised as either participants of a thrombolytic trial (group A, n = 140), receiving non-trial thrombolysis (group B, n = 329), or deemed ineligible for lytic treatment (group C, n = 431). MAIN OUTCOME MEASURES: Background characteristics, inhospital treatment, patterns of follow up, referrals to cardiologists, revascularisation rates, and short and long term survival. RESULTS: Clinical trial recruits were younger by almost 10 years, were less likely to have a previous history of myocardial infarction, and more likely to be in Killip class 1 on admission than those ineligible for thrombolysis. Cardiology follow up was mandatory for all surviving trial participants but 22% of patients in group B and 31% of patients in group C received no follow up, and during four years less than 50% ever saw a cardiologist. Revascularisation was performed in 17.2% of patients in group A, 13.6% of patients in group B, and 7.5% of patients in group C. Cumulative mortality at a median of four years was 24.3% in group A, 36.8% in B, and 59.6% in group C. Adjusting for age, sex, previous myocardial infarction, type of infarction, and Killip class in a logistic regression model the odds ratios (OR) of death at four years for groups B and C were 1.60 (95% confidence intervals (CI) 0.97 to 2.63, p = 0.065) and 2.64 (95% CI 1.61 to 4. 32, p < 0.001), respectively, when compared to group A (OR 1). CONCLUSIONS: Patients enrolled into thrombolytic trials are at low risk. Patients deemed ineligible for thrombolysis are high risk, receive less surveillance, are less likely to be revascularised or receive trial proven treatments, have a poor long term outcome not entirely explained by increased age or severity of infarction, and deserve further evaluation.

Aftercare↗
PubMed1999

Cardiac rehabilitation: socially deprived patients are less likely to attend but patients ineligible for thrombolysis are less likely to be invited.

OBJECTIVE: To identify factors associated with the uptake of cardiac rehabilitation following acute myocardial infarction. DESIGN: Retrospective analysis using multivariate logistic regression modelling. SETTING: Two large teaching hospitals in Nottingham. PATIENTS: Cohorts of patients admitted with acute myocardial infarction in 1992 and 1996. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Factors in multivariate analysis found to be associated with attendance at cardiac rehabilitation. Use of secondary prevention in those who were and were not invited and those who did and did not attend cardiac rehabilitation. RESULTS: 58% of all patients were offered cardiac rehabilitation. Attendance rates were 60% in 1992 and 74% in 1996. Invitations were more likely to be offered to younger patients, those who had received thrombolysis, and to patients admitted to one of the two Nottingham hospitals. Use of secondary prevention was only 48% in 1992 but this increased to 80% in 1996. Patients not receiving secondary prevention were less likely to be invited to cardiac rehabilitation. Social deprivation was the only factor significantly associated with poor uptake of cardiac rehabilitation in both years. There was no difference in the use of secondary prevention between those who did and did not attend cardiac rehabilitation. CONCLUSION: Those invited to attend a cardiac rehabilitation programme are likely to be in a good prognosis group, comprising those who are young and have received thrombolysis. Those at greatest risk, particularly patients from socially deprived areas, seem to be missing out on the potential benefits of cardiac rehabilitation. High risk patients should be specifically targeted to ensure that they are invited to, and encouraged to, attend a programme of cardiac rehabilitation.

Adult↗
PubMed1998

T cell-dependent immune response in C1q-deficient mice: defective interferon gamma production by antigen-specific T cells.

The role of the classical complement pathway in humoral immune responses was investigated in gene-targeted C1q-deficient mice (C1qA-/-). Production of antigen-specific immunoglobulin (Ig)G2a and IgG3 in primary and secondary responses to T cell-dependent antigen was significantly reduced, whereas IgM, IgG1, and IgG2b responses were similar in control and C1qA-/- mice. Despite abnormal humoral responses, B cells from C1qA-/- mice proliferated normally to a number of stimuli in vitro. Immune complex localization to follicular dendritic cells within splenic follicles was lacking in C1qA-/- mice. The precursor frequency of antigen-specific T cells was similar in C1qA-/- and wild-type mice. However, analysis of cytokine production by primed T cells in response to keyhole limpet hemocyanin revealed a significant reduction in interferon-gamma production in C1qA-/- mice compared with control mice, whereas interleukin 4 secretion was equivalent. These data suggest that the classical pathway of complement may influence the cytokine profile of antigen-specific T lymphocytes and the subsequent immune response.

Animals↗
PubMed1998

Regulation of cytoplasmic, surface and soluble forms of CD40 ligand in mouse B cells.

CD40 and CD40 ligand (CD40L) form one of most important receptor-ligand pairs that dock during T-B cell interactions as part of T-dependent antibody responses. It has been reported that among other cell types, B cells can express CD40L. Here we show that a large proportion of mouse B cells express CD40L in their cytoplasm, but not on the surface and that this is readily released as a soluble molecule. Thus, in their resting state up to 50% of mouse B cells express CD40L within their cytoplasm and both the proportion of cells expressing and the amount of CD40L is increased by signaling through immunoglobulin (Ig) or CD38. In contrast, T cell-derived signals such as CD40L (anti-CD40) or Th2-type cytokines cause a decrease in CD40L expression that is related to a release of a soluble form of the molecule from the cell. Supernatants from B cells activated with anti-Ig and anti-CD40 contain CD40L in a variety of forms (18 kDa, 33 kDa and 66 kDa) that are readily detectable by immunoprecipitation with CD40-Fc gamma fusion protein (CD40-Ig) followed by Western blotting with anti-CD40L antibody (MR1). The 33-kDa species is distinct from the 39-kDa membrane-bound molecule found in activated T cells or in resting B cells and appears to be a novel soluble form of CD40L. Inhibition of T cell-independent in vitro stimulation of B cells with CD40-Ig or anti-CD40L suggests that the B cell-derived soluble CD40L or CD40L expressed on the B cell surface can play a positive role in B cell proliferation.

Animals↗
PubMed1998

CD40 ligand signals optimize T helper cell cytokine production: role in Th2 development and induction of germinal centers.

The role of CD40 in the development of germinal centers (GC) is not simply to initiate the B cell response, as rudimentary GC can develop in CD40-/- mice that are injected with CD40-immunoglobulin (Ig) fusion protein. This indicates that CD40 ligand (CD40L) transduces a signal to T cells that is important in the process. In this study we have used an in vitro model of GC development to investigate the role of CD40L, cytokines and other co-stimuli. The model involves the specific induction of an H-2E transgene in GC B cells (in Sma58 mice). We find that Th2 cytokines together with Ig and CD40 cross-linking are the most efficient means of induction of the GC phenotype. Although IL-4 plays some inductive role, it is not the sole active ingredient in the mix of cytokines made by Th2 cells. Our studies on primary T cells and T cell clones activated in the absence of CD40 on antigen-presenting cells or CD40L on T cells indicate that the CD40L co-stimulus does not directly bias the response to Th2 cells, as previously reported, but that it augments terminal effector T cell differentiation or the level of secretory activity. However, both in vitro and in vivo, the CD40L co-stimulus is crucially important for Th2 development as in its absence IL-4 production is suboptimal and does not compete with a larger, more rapid IFN-gamma response.

Animals↗
PubMed1998

Operative outcomes of minimally invasive saphenous vein harvest.

BACKGROUND: The longest incision used in surgery is the standard incision for harvesting the greater saphenous vein for arterial grafting. This long incision is associated with significant pain and morbidity. We present a comparative study between two relatively less invasive techniques: the standard bridge technique (BT) and the endoscopic saphenous vein harvest (ESVH). PATIENTS AND METHODS: This is a prospective, nonrandomized, case-matched study of contemporaneous minimally invasive saphenous vein harvest in patients undergoing multiple vessel coronary artery bypass grafting (CABG). Data points include operative time, total wound length, length of vein harvested, intraoperative complications, conversions to open, injury to the graft, postoperative complications and hospital length of stay. Follow-up continued for 8 weeks postdischarge. RESULTS: Within a 10-month period (July 1996 to May 1997), 60 saphenous vein harvests were performed, with 29 by BT and 31 by ESVH. Patient demographics were well matched, except for a larger number of patients with peripheral vascular disease in the ESVH group. ESVH only required 2.3 incisions versus 5 for the BT (P = 0.000001), whereas ESVH produced on average longer veins of 53.9 cm versus 47.7 cm for BT (P = 0.05). Harvest times were comparable in the two groups. However, mean vein preparation times, incision closure times, and total vein operative times for the BT were, respectively, 18.5 minutes, 35.1 minutes, and 94 minutes versus significantly less times of 11.3 minutes (P = 0.009), 10.6 minutes (P = 0.000001), and 73 minutes (P = 0.0001), respectively, for ESVH. The early, minor wound complication rate was 32% for the ESVH group versus 3% for the BT group (P = 0.0048). However, excluding small wound hematomas, the wound complication rate in the ESVH group fell to 13%. Graft quality was acceptable in both groups. CONCLUSIONS: ESVH was demonstrated to be a useful procedure to harvest saphenous veins for CABG surgery. The ESVH technique allowed the harvesting of a longer vein, via shorter and fewer incisions and in less time. However, for maximum operating room efficiency with the new technology, staff education is essential. There was a greater incidence of minor wound complications in the ESVH group; however, the majority of these ESVH complications were small wound hematomas, which did not occur as surgeon experience with the technique increased.

Aged↗
PubMed1998

Therapeutic potential of recombinant p53 overexpression in breast cancer cells expressing endogenous wild-type p53.

Reconstitution of the p53-dependent apoptotic pathway by gene transfer of a recombinant wild-type p53 minigene leads to rapid apoptotic cell death in breast and other cancer cell types expressing null or mutant p53. Tumour cells expressing wild-type p53 have been reported to be more resistant to this treatment strategy, presumably as a result of mutations in downstream regulators of p53-dependent apoptotic signalling. The MCF-7 breast cancer cell line is representative of this class of tumour cell. Our recent observation of a p53-dependent apoptotic response following adenovirus-mediated HSV thymidine kinase gene transfer and gancyclovir treatment led us to reexamine recombinant p53 cytotoxicity in MCF-7 cells. Infection with a recombinant adenovirus expressing wild-type p53 resulted in a dramatic increase in p53 protein levels and was accompanied by an increase in p21WAF/CIP1 protein levels and G1 arrest within 24 hours post-infection. A significant decrease in MCF-7 cell viability was first observed at 5 days post-infection and coincided with the appearance of morphological and biochemical changes consistent with apoptotic cell death. By day 7 post-treatment, cell viability decreased to 45% and clonogenic survival was reduced to 12% of controls. The results demonstrate that persistent, high level expression of recombinant p53 can induce programmed cell death in MCF-7 cells. While the mechanism by which p53 overexpression overcomes the defect in downstream apoptotic signalling is not clear, our data suggests that this treatment strategy may be beneficial for the class of tumour cells represented by the MCF-7 cell line.

Adenoviridae↗
PubMed1998

Subdivisions of the motor and somatosensory thalamus of primates revealed with Wisteria floribunda agglutinin histochemistry.

We obtained well-differentiated staining of thalamic subdivisions in rhesus macaques and squirrel monkeys using a lectin, Wisteria floribunda agglutinin (WFA), that labels extracellular matrix proteoglycans. Regional variations in staining were observed within the motor and somatosensory thalamic regions that bear on current interpretations of the organization of these regions. The pattern of WFA staining was generally similar to that obtained with Cat-301 antibody, which also stains proteoglycans. However, WFA reliably produced selective staining in both squirrel monkeys and macaques, whereas Cat-301 stained macaques more consistently than squirrel monkeys.

Animals↗
PubMed1998

Changes in the process of care for Medicaid patients with schizophrenia in Utah's Prepaid Mental Health Plan.

OBJECTIVE: Changes in the process of psychiatric care received by Medicaid beneficiaries with schizophrenia were examined after the introduction of capitated payments for enrollees of some community mental health centers (CMHCs) under the Utah Prepaid Mental Health Plan. METHODS: Data from the medical records of 200 patients receiving care in CMHCs participating in the prepaid plan were compared with data from the records of 200 patients in nonparticipating CMHCs, which remained in a fee-for-service reimbursement arrangement. Using the Process of Care Review Form, trained abstracters gathered data characterizing general patient management, social support, medication management, and medical management before implementation of the plan in 1990 and for three follow-up years. Using regression techniques, differences in the adjusted changes between third-year follow-up and baseline were examined by treatment site. RESULTS: By year 3 at the CMHCs participating in the plan, psychotherapy visits decreased, the probability of a patient's terminating treatment or being lost to follow-up increased, the probability of having a case manager increased, the probability of a crisis visit decreased (but still exceeded that at the nonplan sites), and the probability of treatment for a month or longer with a suboptimal dosage of antipsychotic medication increased. Only modest changes in the process of care were observed at the nonplan CMHCs. CONCLUSIONS: Change in the process of psychiatric care was more evident at the sites participating in the plan, where traditional therapeutic encounters were de-emphasized in response to capitation. The array of changes raises questions about the vigor of care provided to a highly vulnerable group of patients.

Adult↗