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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 253 records · Page 14Linked to original sources
PubMed1997

The role of insulin resistance in the natural history of type 1 diabetes.

It is well established that peripheral insulin sensitivity is a critical factor in the aetiology of non-insulin dependent (Type 2) diabetes mellitus (NIDDM). Insulin resistance may also play a role at various stages in the natural history of insulin dependent (Type 1) diabetes (IDDM) and this was the topic of a workshop held in London on Friday 14 July 1995. The mechanisms of insulin resistance in IDDM are ill-defined but probably include 'glucose toxicity'. In the pre-diabetic period, insulin resistance may affect rates of progression to frank hyperglycaemia. Following the clinical onset of IDDM, insulin resistance could influence the length of the 'honeymoon period', diabetic control and patterns of growth during puberty, insulin requirements and blood glucose control at any time, the birth weight of infants born to diabetic mothers, and, through an effect on lipid metabolism and hypertension, ultimately contribute to the excess mortality associated with IDDM. In NIDDM, insulin resistance could influence rates of progression to insulin dependence. Treatment using insulin enhancers in NIDDM patients with autoimmune changes might delay or arrest their usual high-risk of progression to insulin dependence. As it is likely that insulin resistance has a wide-ranging influence on the natural history of diabetes in IDDM patients we suggest that treatment with insulin enhancers may prove beneficial in selected patients.

Adolescent↗
PubMed1997

Cell vehicles for gene transfer to the brain.

Gene products of therapeutic value have been delivered directly to the brain by viral and physical transfer methods and indirectly using cell delivery vehicles. Neural precursor cells, produced by immortalization or expansion with growth factors (e.g. fibroblast growth factor (FGF2)), offer promise both as vehicles for gene delivery to the brain and for their inherent ability to differentiate into neurons and glia in vivo. Their ability to migrate widely throughout the brain after injection, and to integrate in a functional and non-disruptive manner are key advantages over non-neural cells. In mouse models of neurodegenerative disease, transplanted neural precursor cells performed dual functions; they acted as a gene delivery vehicle, supplying a deficient enzyme, and provided some neuroglial cell functions which had been lost. Genetically modified neural precursor transplants influenced the development of inherited neurological disease, establishing the feasibility of this novel approach as a treatment for neurodegenerative disorders.

Animals↗
PubMed1997

Implementing programs for chronic illness management: the case of hypertension services.

BACKGROUND: This article describes the process by which HealthSystem Minnesota (a vertically integrated health care organization), functioning in a competitive managed care environment, has been implementing a hypertension services program. The program involves a team approach to care, with emphasis on patient participation in treatment; decentralized care delivery by nurse coordinators at primary care practice sites; ongoing training and education for patients and providers; and the continuous monitoring and evaluation of patient outcomes and satisfaction. JOB-LEVEL ISSUES: A variety of issues, such as the role and responsibilities of the nurse coordinator, became evident as the program moved towards operational status at four primary care practice sites, which prolonged the implementation period. PROCESS-LEVEL ISSUES: Issues relating to work process changes were more complicated to resolve and required, in some cases, changes in the proposed model. The most significant process-level issues related to educating physicians about the program to secure their participation and support. ORGANIZATION-LEVEL ISSUES: Such issues, which were the most difficult for program implementors to anticipate and resolve, included an organizational culture that emphasized decision making autonomy at primary practice sites. In part, the difficulty encountered in resolving organization-level issues reflected the implementors' lack of awareness of the strength or complexity of the environmental pressures facing the organization, as well as a lack of sensitivity to nuances relating to organizational culture. MOVING AHEAD: Two groups of hypertensive patients--at the implementation and comparison sites--will be compared with respect to satisfaction with care, clinical outcomes, and costs. Expansion of the model to patients with other chronic conditions is under consideration.

Case Management↗
PubMed1997

IsoStar: a library of information about nonbonded interactions.

Crystallographic and theoretical (ab initio) data on intermolecular nonbonded interactions have been gathered together in a computerised library ('IsoStar'). The library contains information about the nonbonded contacts formed by some 250 chemical groupings. The data can be displayed visually and used to aid protein-ligand docking or the identification of bioisosteric replacements. Data from the library show that there is great variability in the geometrical preferences of different types of hydrogen bonds, although in general there is a tendency for H-bonds to form along lone-pair directions. The H-bond acceptor abilities of oxygen and sulphur atoms are highly dependent on intramolecular environments. The nonbonded contacts formed by many hydrophobic groups show surprisingly strong directional preferences. Many unusual nonbonded interactions are to be found in the library and are of potential value for designing novel biologically active molecules.

Biochemical Phenomena↗
PubMed1997

Similarity searching in files of three-dimensional chemical structures: representation and searching of molecular electrostatic potentials using field-graphs.

This paper reports a method for the identification of those molecules in a database of rigid 3d structures with molecular electrostatic potential (MEP) grids that are most similar to that of a user-defined target molecule. The most important features of an MEP grid are encoded in field-graphs, and a target molecule is matched against a database molecule by a comparison of the corresponding field-graphs. The matching is effected using a maximal common subgraph isomorphism algorithm, which provides an alignment of the target molecule's field-graph with those of each of the database molecules in turn. These alignments are used in the second stage of the search algorithm to calculate the intermolecular MEP similarities. Several different ways of generating field-graphs are evaluated, in terms of the effectiveness of the resulting similarity measures and of the associated computational costs. The most appropriate procedure has been implemented in an operational system that searches a corporate database, containing ca. 173,000 3D structures.

Algorithms↗
PubMed1997

Politics, science, and the emergence of a new disease. The case of chronic fatigue syndrome.

Chronic fatigue syndrome (CFS) emerged as a diagnostic category during the last decade. Initial research suggested that CFS was a relatively rare disorder with a high level of psychiatric comorbidity. Many physicians minimized the seriousness of this disorder and also interpreted the syndrome as being equivalent to a psychiatric disorder. These attitudes had negative consequences for the treatment of CFS. By the mid-1990s, findings from more representative epidemiological studies indicated considerably higher CFS prevalence rates. However, the use of the revised CFS case definition might have produced heterogeneous patient groups, possibly including some patients with pure psychiatric disorders. Social scientists have the expertise to more precisely define this syndrome and to develop appropriate and sensitive research strategies for understanding this disease.

Attitude of Health Personnel↗
PubMed1997

Liaison psychiatric nursing in an inner city accident and emergency department.

The Mental Health Nursing Review Team recommend research to examine the potential of liaison mental health nursing. This paper describes a study into the work of two emergency psychiatric nurses (EPN) attached to a central London accident and emergency (A&E) department. A semi-structured interview schedule was employed to generate data on role development and purpose, and a retrospective survey of clinical activity was carried out over a 94-day period. Specific attributes and working practices, which promoted integration within the A&E department, are identified as are the reasons for referring patients to the EPNs, patients' primary problems on assessment, assessment outcome and the staff involved in each assessment. Findings are considered in relation to the various models of psychiatric consultation and liaison found in the literature. The scope and quality of the available data is also assessed and recommendations are made to enable a more robust prospective study to be undertaken.

Emergency Nursing↗
PubMed1997

The prevalence of hereditary haemochromatosis in a diabetic population.

Hereditary haemochromatosis is an under-diagnosed and treatable cause of chronic liver disease. Its prevalence indicates that selective population screening may be worthwhile, but opinion differs as to whether diabetic patients constitute such a group. We studied 727 patients attending a teaching hospital diabetic clinic. On first testing, 7.4% had abnormally high iron indices, but only 3% remained abnormal on retesting. Of these patients, those at high risk were offered liver biopsy for histological assessment and iron assay. Only one had hereditary haemochromatosis, but all had abnormal liver histology--largely steatosis but some with fibrosis. These findings raise questions regarding the true prevalence of this disorder in North-East England, do not indicate that targeted screening of diabetic patients is worthwhile, and incidentally highlight the potential importance of diabetes as a cause of liver disease.

Adult↗
PubMed1997

Bronchoalveolar lavage findings suggest two different forms of childhood asthma.

BACKGROUND: It seems plausible that children with atopy and persistent asthma symptoms will, like their adult counterparts, have chronic airways inflammation. However, many young children with no other atopic features have episodic wheezing that is triggered solely by viral respiratory infections. Little is known as to whether airways inflammation occurs in these two asthma patterns during relatively asymptomatic periods. METHODS: Using a non-bronchoscopic bronchoalveolar lavage (BAL) procedure on children presenting for an elective surgical procedure, this study has investigated the cellular constituents of BAL fluid in children with a history of atopic asthma (AA) non-asthmatic atopic children (NAA) or viral associated wheeze (VAW). RESULTS: A total of 95 children was studied: 52 with atopic asthma (8.0 years, range 1.1-15.3, 36 male), 23 with non-asthmatic atopy (median age 8.3 years, range 1.7-13.6, 11 male) and 20 with VAW (3.1 years, range 1.0-8.2, 13 male). No complications were observed during the lavage procedure and no adverse events were noted post-operatively. Total lavage fluid recovered was similar in all groups and the total cell numbers were higher in the VAW group. Eosinophil (P < or = 0.005) and mast cell (P < or = 0.05) numbers were significantly elevated in the group with atopic asthma. CONCLUSIONS: During relatively asymptomatic periods there is on-going airways inflammation, as demonstrated by eosinophil and mast cell recruitment, in children with asthma and atopy but not in children with viral associated wheeze or atopy alone. This strongly suggests that there are different underlying pathophysiological mechanisms in these two groups of children who wheeze.

Adolescent↗
PubMed1997

Time delay in the treatment of acute myocardial infarction (AMI): a comparison of primary percutaneous transluminal coronary angioplasty (PTCA) with thrombolysis.

BACKGROUND: If primary percutaneous transluminal coronary angioplasty (PTCA) cannot be performed within times comparable to thrombolysis, the possible advantages of that management may be offset by the logistic difficulties associated with its delivery. AIM: To measure and compare the time delay involved in administration of thrombolysis and primary PTCA over a one year period and examine causes for delay greater than 60 minutes. METHOD: Prospective data collection on all patients treated with primary PTCA or thrombolysis. A quality improvement process was applied. RESULTS: Eighty-five patients were treated with thrombolysis with a delay of 39 +/- 8 (SD) minutes, 12 patients being treated more than 60 minutes after presentation. Primary PTCA was used in 79 patients with a delay of 48 +/- 12 (SD) minutes, 21 patients being treated after more than 60 minutes. Time delays in the two management groups were significantly different (p = 0.03) but that in primary PTCA during routine hours was not significantly different from that in thrombolysis treated patients (p = 0.07). Causes for revascularisation delay greater than 60 minutes from presentation are discussed. CONCLUSIONS: With appropriate facilities and organisation, patients with acute myocardial infarction presenting within normal working hours can be treated with primary PTCA without compromising their care due to time delay. Many patients managed with primary revascularisation by thrombolysis or primary PTCA with a delay of more than 60 minutes have identifiable clinically appropriate delays.

Angioplasty, Balloon, Coronary↗
PubMed1997

The occurrence of cancer in a cohort of New South Wales coal miners.

To describe the incidence of cancer in coal miners in New South Wales (NSW) between 1973 and 1992, an inception cohort of all male coal industry employees who entered the industry between 1 January 1973 and 31 December 1992 was constructed from the medical examination records of the Joint Coal Board. This cohort was matched with the NSW State Cancer Registry to determine the occurrence and type of cancer. In the cohort of 23,630 men, 297 developed 301 primary cancers in the 20-year period of observation. The standardised incidence ratio (SIR) for all cancers was 0.82. Stomach cancer has been reported to be common in coal miners but the SIR for stomach cancer was not higher than average in this cohort. A cluster of non-Hodgkin's lymphoma has been reported in a NSW coal mine but an increased risk of this cancer was not evident in the industry as a whole. Similarly a cluster of cases of brain tumour has been reported. In this cohort, the SIR for brain tumour was 1.05 (95 per cent confidence interval (CI) 0.57 to 1.76) and a risk for brain tumour remains unconfirmed. The SIR for malignant melanoma was 1.13 (CI 0.90 to 1.39) together and 2.02 (CI 1.31 to 2.98) for those workers who started in an open-cut mine. Overall, there does not appear to be a general risk of cancer in the NSW coal industry. Open-cut miners have an increased risk of malignant melanoma, which may be related to their exposure to the sun at work.

Adult↗
PubMed1997

Breast cancer five-year survival in New South Wales women, 1972 to 1991.

This study of breast cancer survival is based on analysis of five-year relative survival of 38,362 cases of invasive breast cancer in New South Wales (NSW) women, incident between 1972 and 1991, with follow-up to 1992, using data from the population-based NSW Central Cancer Registry. Survival was ascertained by matching the registry file of breast cancers against NSW death certificates from 1972 to 1992, mainly by automated probabilistic linkage. Absolute survival of cases was compared with expected survival of age- and period-matched NSW women. Proportional hazard regression analysis was used for examination of the effects on excess mortality of age, period of diagnosis and degree of spread at diagnosis. Relative survival at five years increased from 70 per cent in 1972-1976 to 77 per cent in 1987-1991. Survival improved during the 1970s and in the late 1980s. Regression analysis suggested that part of the improved survival in the late 1980s was due to lesser degree of spread at diagnosis, whereas the improved survival during the 1970s may have been due to treatment. Survival was better for those aged 40-49 years (RR = 0.86) and worse for those aged > or = 70 years (RR = 1.22) compared with the referent group (60-69 years). Excess mortality was much less for those with invasive localised disease than those with regional spread (RR = 3.1) or metastatic cancer (RR = 15.5) at diagnosis. For the most recent period (1987-1991), relative five-year survival was 90, 70 and 18 per cent, respectively, for the three degree-of-spread categories.

Adult↗
PubMed1997

Breast cancer five-year survival, by New South Wales regions, 1980 to 1991.

Breast cancer five-year relative survival was calculated for 16 urban and rural regions in New South Wales (NSW) for cases incidents in 1980-1991. Survival analysis employed cancer registry data linked with the death register, and age- and period-matched regional mortality of NSW women. Proportional hazard regression analysis was used to compare excess mortality in breast cancer cases in each region. The effect of region was significant (P < 0.05) in analysis, after age and the follow-up variable (and their interaction) were adjusted for, although no region was significantly different from the referent group (chosen because of average relative five-year survival). When degree of spread and its interactions were entered into the model, the effect of region became nonsignificant. A significant linear trend (P < 0.05) in the adjusted relative risk for excess mortality in breast cancer cases was noted when regions were divided into quartiles based on socioeconomic status, with higher relative risk in low-socioeconomic-status groups; this effect also disappeared with adjustment for degree of spread at diagnosis. There was no general effect of rurality versus capital city or other metropolitan centres. This study demonstrates a small effect of region of residence and implied socioeconomic status on breast cancer survival in NSW women, but this becomes nonsignificant when the data are adjusted for degree of spread at diagnosis. This suggests that earlier diagnosis would be of benefit in reducing minor inequalities in breast cancer survival in NSW women.

Adult↗
PubMed1997

A review of health effects of aircraft noise.

Social surveys have established dose-response relationships between aircraft noise and annoyance, with a number of psychological symptoms being positively related to annoyance. Evidence that exposure to aircraft noise is associated with higher psychiatric hospital admission rates is mixed. Some evidence exists of an association between aircraft noise exposure and use of psychotropic medications. People with a pre-existing psychological or psychiatric condition may be more susceptible to the effects or exposure to aircraft noise. Aircraft noise can produce effects on electroencephalogram sleep patterns and cause wakefulness and difficult in sleeping. Attendances at general practitioners, self-reported health problems and use of medications, have been associated with exposure to aircraft noise, but some findings are inconsistent. Some association between aircraft noise exposure and elevated mean blood pressure has been observed in cross-sectional studies of schoolchildren, but with little confirmation from cohort studies. There is no convincing evidence to suggest that all-cause or cause-specific mortality is increased by exposure to aircraft noise. There is no strong evidence that aircraft noise has significant perinatal effects. Using the World Health Organization definition of health, which includes positive mental and social wellbeing, aircraft noise is responsible for considerable ill-health. However, population-based studies have not found strong evidence that people living near or under aircraft flight paths suffer higher rates of clinical morbidity or mortality as a consequence of exposure to aircraft noise. A dearth of high quality studies in this area precludes drawing substantive conclusions.

Aircraft↗
PubMed1997

Asthma mortality in Australia 1920-94: age, period, and cohort effects.

STUDY OBJECTIVE: To investigate asthma mortality during 1920-94 in Australia in order to assess the relative role of period and birth cohort effects. DESIGN: Asthma mortality (both sexes) was age standardised and examined for changes over time. The data were also examined for age, period, and cohort (APC) effects using Poisson regression modelling. SETTING: National Australian mortality data. PARTICIPANTS: Population (both sexes) aged 15-34 years, 1920-94. MAIN RESULTS: Age adjusted period rates indicate an increase in asthma mortality during the 1950's, and increases and subsequent falls (epidemics) during the mid 1960s and late 1980s. APC modelling suggested an increasing cohort effect (adjusted for both age and period) from the birth cohort 1950-54 onwards. Period effects (adjusted for age and cohort) are characterized by an increase in the 1950s (possibly due to changes in diagnostic labelling), minimal or no increases in the mid 1960s and late 1980s (where period peaks had been noted when data were adjusted for age only), and declines in mortality risk subsequent to the periods where age-period analysis had noted increases. Thus, in Australia, some of the mid 1960s epidemic in asthma deaths, and all of the late 1980s mortality increase, seem to be attributable to cohort effects. CONCLUSIONS: The increase in asthma mortality cohort effect is consistent with empirical evidence of recent increases in prevalence (and presumably incidence) of asthma in Australia, and suggests the need for more research into the underlying environmental aetiology of this condition.

Adolescent↗