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Biomedical subjects

A Reid

Publications and source records attributed to A Reid.

At least 37 records · Page 2Linked to original sources
PubMed2000

Quantitative assays for the chick chorioallantoic membrane.

Focal application of angiogenic substances to the chick chorioallantoic membrane is quick and easy as a rapid screening test, but is susceptible to artefactual stimulation induced by carriers, hyperosmolarity, proteolytic activity, and indeed any cause of damage to the CAM. This can be deceptive and unanticipated. Focal application methods can be used for subsequent measurement by morphometry of the increased vascularity forming the typical spokewheel pattern of supply vessels. If test and control substances are applied in liquid form to the whole dropped CAM surface, then a much wider variety of quantitative morphometric, histological and biochemical techniques can be applied. Assessment of arterial vascularity, terminal arterial branching, supply vessels in cross-sections, and CAM haemoglobin content are direct measures of angiogenic effects, but are time-consuming. Biochemical assays of collagen, protein and DNA synthesis parallel the other assays, and these parameters can be estimated more quickly within the working week. There is inherent variability in the outbred strains of hen eggs currently commercially available. This means that all assays require substantial group numbers to achieve statistical validity, generally not less than 10 eggs per group. The biochemical assays yield interesting time-course patterns that distinguish between different types of angiogenic stimulants.

Animals↗
PubMed2000

Locating the active site for angiogenesis and cell proliferation due to fibrin fragment E with a phage epitope display library.

The plasmin-mediated lysis of fibrin present in a wound, or in chronic inflammatory disease, results in the release of fibrin degradation products. One of the two major products is fibrin fragment E, which has been shown to stimulate cell proliferation in many cell types including endothelium, fibroblasts, and smooth muscle cells, and to be angiogenic in the chick chorioallantoic membrane (CAM) system. The activity of fibrin fragment E is dependent on N-terminus thrombin action. Antibodies against fibrin E, which block the cell proliferative activity, were used to locate the active site. Phage epitope display libraries were used to identify the sequence of a peptide, which resembles a region of the N terminus structure. The equivalent synthetic peptide (WTM110) has optimal stimulatory properties at equimolar concentrations to the parent molecule. Such peptide information has therapeutic potential for both stimulating and suppressing angiogenesis and cell proliferation.

Amino Acid Sequence↗
PubMed2000

An economic evaluation of occupational health.

There is an increasing need to evaluate the costs and benefits of an occupational health service (OHS). However, measuring benefits from an OHS is inherently difficult. Instead, an economic model can be constructed to present the minimum threshold benefits required for OHSs to be cost-effective, given what is known about costs. This model assumes that the benefits of an OHS are to maximize health and morale of employees; maximize performance and increase productivity; minimize medico-legal costs; enhance workplace safety; and reduce sickness absence. A certain distribution across these benefits can be assumed for each OHS. The overall required value of all benefits brought about by use of an OHS is in the range 158-199 Pounds per year. The plausibility of results can be assessed using known data and judgement. Despite many uncertainties it is likely that the minimum benefit thresholds will be achieved overall.

Cost-Benefit Analysis↗
PubMed2000

Program directors' perspectives on federally funded fellowship training in primary care research.

PURPOSE: To describe the organization, models of training, and institutional impact of National Research Service Award fellowship programs in primary care research. METHOD: Survey of 25 directors of currently-funded and former training sites. RESULTS: Twenty-four program directors (96%) completed the survey. Programs allocated 39% of fellows' time to course work leading to an advanced degree or other didactic instruction, and 40% of time to the conduct of research. Collaborations with other training programs within the institution occurred at 83% of sites. Programs commonly (54%) or exclusively (42%) relied on a research model of "early research independence" in which the fellow defined an area of research interest, rather than an "apprenticeship" model in which the fellow worked in a senior investigator's research area. These programs enriched the local academic environment, but required extensive financial subsidies. The high costs of training often had adverse impacts on recruitment and other components of the training process. CONCLUSION: Research training programs in primary care often substitute acquisition of advanced degrees for early immersion in research. The "early independence" model of research differs from fellowships in the medical specialties, and requires further study to assess its effectiveness. The need to subsidize training costs poses substantial problems for the institutions that host these fellowship programs.

Attitude of Health Personnel↗
PubMed2000

Psychiatric symptomatology in borderline and other personality disorders: dissociation and fragmentation as mediators.

This study considered the role of dissociation and personality fragmentation as psychological factors that might distinguish borderline and personality disorder (BPD) patients, and that might explain why BPD patients have higher levels of other psychiatric symptomatology than those with other personality disorders. Two groups of personality-disordered patients (personality disorders including BPD; personality disorders other than BPD) completed measures of dissociation, personality fragmentation, and psychiatric disturbance. The BPD group had higher levels of a number of aspects of psychiatric symptomatology. Those differences were mediated by aspects of dissociation. Personality fragmentation differentiated the two groups but was not related to the higher levels of other aspects of psychiatric disturbance. Treating the syndrome of BPD may depend on addressing both dissociation and personality fragmentation. In contrast, reducing the level of comorbid psychiatric disturbance in BPD is likely to be more strongly dependent on reducing levels of different aspects of dissociation. Psychotherapeutic techniques and targets for achieving such change are discussed.

Adult↗
PubMed2000

Cannabis use among Australian adolescents: findings of the 1998 National Drug Strategy Household Survey.

OBJECTIVE: To describe the prevalence, context and recent trends in cannabis use among Australian adolescents. METHOD: Data was collected from 1,581 adolescents aged 14-19 years as part of the 1998 National Drug Strategy Household Survey, and comparisons were made with data from 350 adolescents who participated in the 1995 survey. RESULTS: Among 14-19 year olds, 47.8% have had the opportunity to use cannabis in the past year and 45.2% have used cannabis at least once in their lifetime. Substantial increases have occurred since 1995 in the prevalence of use among young females. While most cannabis use was fairly infrequent, a minority of 14-19 year olds (9.4%) used cannabis at least weekly. Cannabis use was associated with regular tobacco and alcohol use, and other illicit drug use. Regular cannabis users had lower levels of health on the general health and vitality dimensions of the SF-36. IMPLICATIONS: These results show that cannabis availability and use is common among Australian adolescents, and confirm that there has been an increase in use between 1995 and 1998, although only among young females. Future research is required to understand why this recent increase has occurred, and trends in cannabis uptake and use patterns among this group should be carefully monitored. Interventions may need to be developed and made available to the group of young people who are using cannabis heavily.

Adolescent↗
PubMed2000

Trial-of-antibiotic algorithm for the diagnosis of tuberculosis in a district hospital in a developing country with high HIV prevalence.

OBJECTIVE: To evaluate a diagnostic algorithm for pulmonary tuberculosis based on smear microscopy and objective response to trial of antibiotics. SETTING: Adult medical wards, Hlabisa Hospital, South Africa, 1996-1997. METHODS: Adults with chronic chest symptoms and abnormal chest X-ray had sputum examined for Ziehl-Neelsen stained acid-fast bacilli by light microscopy. Those with negative smears were treated with amoxycillin for 5 days and assessed. Those who had not improved were treated with erythromycin for 5 days and reassessed. Response was compared with mycobacterial culture. RESULTS: Of 280 suspects who completed the diagnostic pathway, 160 (57%) had a positive smear, 46 (17%) responded to amoxycillin, 34 (12%) responded to erythromycin and 40 (14%) were treated as smear-negative tuberculosis. The sensitivity (89%) and specificity (84%) of the full algorithm for culture-positive tuberculosis were high. However, 11 patients (positive predictive value [PPV] 95%) were incorrectly diagnosed with tuberculosis, and 24 cases of tuberculosis (negative predictive value [NPV] 70%) were not identified. NPV improved to 75% when anaemia was included as a predictor. Algorithm performance was independent of human immunodeficiency virus status. CONCLUSION: Sputum smear microscopy plus trial of antibiotic algorithm among a selected group of tuberculosis suspects may increase diagnostic accuracy in district hospitals in developing countries.

AIDS-Related Opportunistic Infections↗
PubMed1999

Acute paw oedema induced by local injection of adenosine A(1), A(2) and A(3) receptor agonists.

The present study used plethysmometry to examine oedema following local injection of selective adenosine A(1), A(2) and A(3) receptor agonists and inhibitors of adenosine metabolism into the hindpaw of the rat. N(6)-Cyclopentyladenosine and L-N(6)-phenylisopropyladenosine (A(1)), 2-[p(2-carboxyethyl) phenethylamino]-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS21680) (A(2A)) and N(6)-benzyl-5'-N-ethylcarboxamido adenosine (N(6)-B-NECA) (A(3)) all produced an increase in paw volume (N(6)N(6)-cyclopentyladenosine, L-N(6)CGS21680). At the highest dose, each agent also produced a systemically mediated suppression of oedema. Oedema by N(6)-cyclopentyladenosine was blocked by caffeine, 8-cyclopentyl-1,3-dimethylxanthine and enprofylline. Oedema by CGS21680 was blocked by caffeine and 8-cyclopentyl-1, 3-dimethylxanthine. Oedema by N(6)-B-NECA was blocked by enprofylline, but not by caffeine or 8-cyclopentyl-1, 3-dimethylxanthine, or by systemic administration of MRS 1191. Oedema by both N(6)-cyclopentyladenosine and N(6)-B-NECA was blocked by mepyramine, ketanserin and phentolamine, but that by CGS21680 was not. The adenosine kinase inhibitor 5'-amino-5'-deoxyadenosine and the adenosine deaminase inhibitor 2'-deoxycoformycin produced only a limited increase in paw volume, and this was blocked by caffeine. This study demonstrates an acute paw oedema response following local administration of adenosine A(1), A(2) and A(3) receptor agonists, which likely results from different mechanisms of action in each case.

Acute Disease↗
PubMed1999

Incidence of testicular germ-cell malignancies in England and Wales: trends in children compared with adults.

The incidence of testicular cancer has been increasing markedly in most industrialised countries. This rise is known to have affected young adults, but it is less clear whether it has affected other age groups, particularly children. We used data from the National Cancer Registry file at the Office of National Statistics (ONS) and the National Registry of Childhood Tumours to examine trends in testicular germ-cell malignancies overall in England and Wales from 1962 to 1990 and in children from 1962 to 1995. The incidence of testicular cancer at all ages rose by 3.4% (95% CI 3.3-3.6%) per annum from 1962 to 1990. A similar rise in the incidence of germ-cell malignancies occurred during the years for which histological information was available in the ONS files, 1971-1989 (3.4%; 3.1-3.6%), to which both seminomas and non-seminomas contributed equally. The incidence of non-seminomas in adults rose in men under age 55 years and declined in older men, whereas there were increases in the incidence of seminomas in both young and older men. Cohort analysis at young ages showed a marked rise in the risk of germ-cell malignancies up to the cohort born in 1955-1959 but no further rise for those born subsequently. The rise in the incidence of these tumours in young adults was paralleled by a similar trend, although less marked, in children aged under 15 years (1.3% per annum; 0.2-2.5%). The increase in risk for children in this very large data set alongside the rise in young adults is compatible with the hypothesis that childhood and adult testicular germ-cell malignancies may have some common risk factors, presumably pre-natal.

Adolescent↗
PubMed1999

Relapse and mortality among HIV-infected and uninfected patients with tuberculosis successfully treated with twice weekly directly observed therapy in rural South Africa.

OBJECTIVE: To determine post-treatment relapse and mortality rates among HIV-infected and uninfected patients with tuberculosis treated with a twice-weekly drug regimen under direct observation (DOT). SETTING: Hlabisa, South Africa. PATIENTS: A group of 403 patients with tuberculosis (53% HIV infected) cured following treatment with isoniazid (H), rifampicin (R), pyrazinamide (Z) and ethambutol (E) given in hospital (median 17 days), followed by HRZE twice weekly to 2 months and HR twice weekly to 6 months in the community under DOT. METHODS: Relapses were identified through hospital readmission and 6-monthly home visits. Relapse (culture for Mycobacterium tuberculosis) and mortality given as rates per 100 person-years observation (PYO) stratified by HIV status and history of previous tuberculosis treatment. RESULTS: Mean (SD) post-treatment follow-up was 1.2 (0.4) years (total PYO = 499); 78 patients (19%) left the area, 58 (14%) died, 248 (62%) remained well and 19 (5%) relapsed. Relapse rates in HIV-infected and uninfected patients were 3.9 [95% confidence interval (CI) 1.5-6.3] and 3.6 (95% CI 1.1-6.1) per 100 PYO (P = 0.7). Probability of relapse at 18 months was estimated as 5% in each group. Mortality was four-fold higher among HIV-infected patients (17.8 and 4.4 deaths per 100 PYO for HIV-infected and uninfected patients, respectively; P<0.0001). Probability of survival at 24 months was estimated as 59% and 81%, respectively. We observed no increase in relapse or mortality among previously treated patients compared with new patients. A positive smear at 2 months did not predict relapse or mortality. CONCLUSION: Relapse rates are acceptably low following successful DOT with a twice weekly rifampicin-containing regimen, irrespective of HIV status and previous treatment history. Mortality is substantially increased among HIV-infected patients even following successful DOT and this requires further attention.

AIDS-Related Opportunistic Infections↗
PubMed1999

Infrainguinal revascularisation in the era of vein-graft surveillance--do clinical factors influence long-term outcome?

OBJECTIVES: To investigate the variables affecting the long-term outcome of infrainguinal vein bypass grafts that have undergone postoperative surveillance. DESIGN: A retrospective analysis. PATIENTS AND METHODS: Details of 299 consecutive infrainguinal vein grafts performed in 275 patients from a single university hospital were collected and analysed. All grafts underwent postoperative duplex surveillance. Factors affecting patency, limb salvage and survival rates were examined. These factors were gender, diabetes, hypertension, aspirin, warfarin, ischaemic heart disease, run-off, graft type, early thrombectomy, level of anastomoses and indication for surgery. RESULTS: The 6-year primary, primary assisted and secondary patency rates were 23, 47, and 57%, respectively. Six-year limb salvage and patient survival were 68 and 45%, respectively. Primary patency was adversely influenced by the use of composite vein grafts. Early thrombectomy was the only factor that significantly influenced secondary patency. Limb salvage was worse in diabetic limbs, limbs with poor run-off and in grafts that required early thrombectomy. Postoperative survival was better in males, claudicants and in patients who took aspirin. CONCLUSIONS: Although co-morbid factors did not influence graft patency rates, diabetes did adversely effect limb salvage. This study, like others before it, confirms that aspirin significantly reduces long-term mortality in patients undergoing infrainguinal revascularisation.

Angioplasty↗
PubMed1998

Vitamin E, lipids, and lipid peroxidation products in tardive dyskinesia.

BACKGROUND: Lipid peroxidation has been postulated as a possible mechanism for neuronal damage in tardive dyskinesia, and this is supported by evidence of increased lipid peroxidation products in the cerebrospinal fluid of dyskinetic subjects. METHODS: In this study plasma levels of vitamin E and vitamin A, measured by high-performance liquid chromatography, and of thiobarbituric acid-reactive substances (TBARS), were determined in 16 schizophrenic patients with tardive dyskinesia, 16 nondyskinetic patients all assessed by Abnormal Involuntary Movement Scale (AIMS), and 10 normal control subjects. Plasma cholesterol and triglyceride were also measured throughout. Vitamin E levels in plasma were corrected for total lipids. RESULTS: Multivariate analysis of covariance showed significant differences when vitamin E and TBARS were compared in the three groups. Univariate t tests showed a significantly lower lipid-corrected vitamin E (p = .018) between the normal and dyskinetic group but not between the normal and the nondyskinetic schizophrenic patients. There was no difference in vitamin A levels between patients and normal controls. TBAR results showed a significant positive correlation between AIMS score and lipid-corrected TBARS. CONCLUSIONS: This study confirms an abnormality associating lipid peroxidation and tardive dyskinesia and extends this abnormality to measurements of lipid-corrected vitamin E in plasma.

Aged↗
PubMed1998

The increasing workload required to maintain infrainguinal bypass graft patency.

BACKGROUND: To assess the impact upon the provision of a vascular service of the workload associated with maintaining infrainguinal bypass graft patency. DESIGN: A computerised prospective audit. MATERIALS AND METHODS: Between January 1990 and December 1995, all patients with infrainguinal bypass grafts were entered into a prospective computerised audit to monitor interventions for the maintenance of graft patency. Excluded from the study were interventions during the first 30 postoperative days and procedures not directly related to the graft. A graft surveillance programme was in operation throughout. RESULTS: During the study period a total of 131 patients with 144 grafts were admitted on 330 occasions and required 401 separate interventional procedures. There were 227 procedures in 72 femorodistal grafts, 116 in 38 below-knee femoropopliteal grafts and 58 interventions in the group of 34 above-knee femoropopliteal grafts. Radiological interventions accounted for almost 70% of this workload. CONCLUSION: The workload associated with the maintenance of infrainguinal bypass grafts increased considerably during the study period, and seems likely to increase further. Such interventions should therefore be considered when planning for vascular service provision.

Anastomosis, Surgical↗
PubMed1998

General practitioners' attitudes to psychiatric and medical illness.

BACKGROUND: General practitioners are increasingly involved in the care of patients with long-term psychiatric disorders. We have previously reported that general practitioners are less willing to treat patients with schizophrenia than those without such a diagnosis, but this may have been attributable to a reluctance to treat patients with any psychiatric or chronic illness. We, therefore, examined general practitioners' attitudes to patients with chronic psychiatric or medical illnesses. METHODS: A random sample of 260 local general practitioners were each sent one of our case vignettes which were identical apart from mention of a previous diagnosis of schizophrenia, depression, diabetes or no illness. The general practitioners were asked to indicate their level of agreement with 13 attitudinal statements based on the vignette. RESULTS: One hundred and sixty-six (66%) of the general practitioners responded to the case vignettes. Those responding to the vignette about the patient with schizophrenia were less happy to have that patient on their practice list and were more concerned about the risk of violence and the child's welfare. Those responding to the depression vignette were more likely to offer the patient antidepressants or counselling; and those who replied to the diabetes case were most likely to refer the patient to a hospital specialist. These differences were not attributable to the personal or practice characteristics of the general practitioners. CONCLUSIONS: Patients with schizophrenia arouse concerns in general practitioners that are not simply due to those patients suffering from a psychiatric or chronic illness. Our results suggest that some patients with schizophrenia may find it difficult to register with a general practitioner and receive the integrated community-based health care service they require. Psychiatrists should provide education and support to general practitioners who look after patients with schizophrenia.

Adult↗
PubMed1998

Trends in cancer incidence and mortality in Scotland: description and possible explanations.

Secular and cohort trends in mortality from cancer in Scotland during 1953-93, and incidence during 1960-90, were analysed using individual records from the national mortality and registration files. For certain cancer sites, the secular analyses of mortality were extended back to 1911 by use of published data. Mortality from cancer at older ages in Scotland has increased over the last 40 years. In each sex, this trend has been dominated by the effects of smoking: all-cancer rates and rates of lung cancer, now the most common fatal cancer in men and in women in Scotland, reached a peak in the cohort of men born at the turn of the century and the cohort of women born in the 1920s. For much of the period, the Scottish all-age rates of lung cancer were the highest reported in the world; they are now decreasing on a secular basis in men, but are still increasing in women. There have also been large increases at older ages in the incidence and mortality rates for cancer of the prostate in recent years. bladder cancer, nervous system cancer, non-Hodgkin's lymphoma, myeloma and leukaemia; for each there is likely to be a considerable artefactual element to the increase, with differing degrees of possibility that there may in addition be an element of real increase. Substantial decreases in mortality at all ages have occurred for stomach and colorectal cancers and substantial increases at all ages for pleural cancer and melanoma. Rates of mortality from breast cancer, the most common cancer in women in Scotland, have generally increased over the past 80 years; a temporary cessation in this upward trend occurred in the years during and after the Second World War, and recently rates have turned downward, probably at least in part because of better treatment. Mortality from ovarian cancer, the second most common reproductive-related female tumour in Scotland, has also increased at older ages. At younger ages, mortality from cancer in Scotland has decreased, especially in men, whereas incidence has not. This divergence, which has been a consequence of better treatment, has occurred especially for cancers of the testis and ovary, Hodgkin's disease and leukaemia. There have been increases at young adult ages, however, in both mortality from and incidence of oral and pharyngeal, oesophageal and laryngeal cancers in men, and melanoma and non-Hodgkin's lymphoma in each sex. Cervical cancer rates at young ages also increased, but this trend has reversed for incidence in the most recent birth cohorts. Incidence rates have also increased for testicular cancer in young adults and leukaemia in children. With the possible exceptions of non-Hodgkin's lymphoma and childhood leukaemia, the increasing rates are likely largely to reflect real rises in incidence, and they highlight the need for investigation of the causes of these cancers, and, when causes are known, for preventive action.

Adolescent↗