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D H Taylor

Publications and source records attributed to D H Taylor.

At least 37 records · Page 2Linked to original sources
PubMed1998

The natural life of policy indices: geographical problem areas in the U.S. and U.K.

In spite of many fundamental differences between the health systems in the U.S. and U.K., each has pursued a policy of identifying geographical small-areas believed to have inadequate primary care physicians given local health care needs. The magnitude of the problems in such areas differ in the U.S. and U.K. leading to idiosyncratic policy responses that are dictated by overall health system realities. However, there are several common themes identified in this comparative study: goals for remedial health policy are often unclear, making evaluation difficult; in the absence of conceptual clarity, a consensus-based approach of identifying existing and widely available variables to designate areas has been used to identify geographical problem areas; there are widespread concerns that the present indices used to implement policy are inappropriate, but no alternative index has been adopted. The paper concludes that clarifying goals for remedial health policy is key if the effectiveness of such policy is to be improved. Guidelines for assessing the usefulness of existing and future indices used to designate areas as eligible for resources as a part of this type of small-area remedial policy are developed from this U.S./U.K. comparison.

Guidelines as Topic↗
PubMed1998

General practitioner turnover and migration in England 1990-94.

BACKGROUND: In tandem with fears about a GP workforce crisis, increasing attention is being focused on the supply and distribution of primary care services: on general practitioners in particular. Differential turnover and migration across health authority boundaries could lead to a maldistribution of GPs, yet comprehensive studies of GP turnover are non-existent. AIM: To quantify general practitioner (GP) turnover and migration in England from 1990 to 1994. METHOD: Yearly data from 1 October 1990 to 1 October 1994 were collected on GPs in England practising full time, including average yearly turnover, rates of entry to and exit from general practice, and net migration among GPs. All were calculated at the family health service authority (now the new health authorities) level. RESULTS: Average yearly GP turnover ranges from 2.9% in Shropshire to 7.8% in Kensington, Chelsea and Westminster; turnover is associated with deprivation and high-need areas. Migration of GPs across health authority borders was rare. Entry and exit rates were also positively related to measures of deprivation and need. Relatively underprovided health authorities lost 23 GPs over the study period as a result of migration; relatively overprovided ones gained three. CONCLUSION: Turnover is driven primarily by exits from general practice and is related to deprivation and high need. Retention appears to be the main problem in ensuring an adequate GP supply in relatively deprived and underprovided health authorities.

England↗
PubMed1997

Recruitment, retention, and time commitment change of general practitioners in England and Wales, 1990-4: a retrospective study.

OBJECTIVES: To describe the recruitment and retention of general practitioners and changes in their time commitment from 1 October 1990 to 1 October 1994. DESIGN: Retrospective analysis of yearly data. SETTING: England and Wales. SUBJECTS: General practitioners in unrestricted practice. MAIN OUTCOME MEASURES: Numbers of general practitioners moving into and out of general practice; proportion of general practitioners practising less than full time; proportion of general practitioners having unchanged time commitment over the study period; and proportion of general practitioners leaving general practice in 1991 who were subsequently practising in 1994. RESULTS: Numbers of general practitioners entering general practice (1565 in 1990, 1400 in 1994) fell over the study period as did the numbers leaving general practice (1488 in 1990, 1115 in 1994). The net effect was an increase in both the total and full time equivalent general practitioners practising from 1 October 1990 (26,757 full time equivalents) to 1 October 1994 (27,063 full time equivalents). Numbers of general practitioners practising full time were decreasing whereas part time practice was increasing; women were more likely to practise part time. 35.5% (43/121) of women practising full time and 17.8% (24/135) of men practising full time who left practice in 1991 were practising again in 1994. CONCLUSION: Simply using total numbers of general practitioners or net increase to describe workforce trends masks much movement in and out of general practice and between differing time commitments. Recruitment and retention issues need to be separated if reasonable policies are to be developed to assure the necessary general practitioner workforce for a primary care led NHS.

Adult↗
PubMed1997

Partnership changes in English general practice from 1990 to 1994.

BACKGROUND: The objective of this study was to quantify the rate of partnership change among general practitioners (GPs) in the National Health Service (NHS) in England from 1990 to 1994. METHODS: Time series data on English GPs were analysed on 1 October for the years 1990-1994. The main outcome measures include: (1) proportion of GPs practising in an unchanged partnership from 1 October 1990 to 1 October 1994; (2) proportion of partnerships that were unchanged over the study period; (3) the average yearly rate of partnership changes for England and per Family Health Service Authority (FHSA), calculated using both the individual GP and the practice as the unit of analysis. RESULTS: A total of 6532 (27.1 per cent) of the 24,107 unrestricted GPs practising full time on 1 October 1990 were still practising in the identical partnership on 1 October 1994; 3539 (35.7 per cent) of the 9918 practices in England were unchanged over the same period. The average yearly partnership change rate for all England was 23.1 per cent when calculated using the individual GP as the unit of analysis, and 23.4 per cent when calculated using the practice as the unit of analysis. There is threefold variation found in the average yearly partnership change rate by FHSA, with similar rank ordering of health authorities when using either the individual GP or practice as unit of analysis. CONCLUSIONS: Changes in partnerships are commonplace. The possible influence of such changes on primary care in the NHS should be further investigated.

England↗
PubMed1996

X-ray digital imaging petrography of lunar mare soils: modal analyses of minerals and glasses.

It is essential that accurate modal (i.e., volume) percentages of the various mineral and glass phases in lunar soils be used for addressing and resolving the effects of space weathering upon reflectance spectra, as well as for their calibration such data are also required for evaluating the resource potential of lunar minerals for use at a lunar base. However, these data are largely lacking. Particle-counting information for lunar soils, originally obtained to study formational processes, does not provide these necessary data, including the percentages of minerals locked in multi-phase lithic fragments and fused-soil particles, such as agglutinates. We have developed a technique for modal analyses, sensu stricto, of lunar soils, using digital imaging of X-ray maps obtained with an energy-dispersive spectrometer mounted on an electron microprobe. A suite of nine soils (90 to 150 micrometers size fraction) from the Apollo 11, 12, 15, and 17 mare sites was used for this study. This is the first collection of such modal data on soils from all Apollo mare sites. The abundances of free-mineral fragments in the mare soils are greater for immature and submature soils than for mature soils, largely because of the formation of agglutinitic glass as maturity progresses. In considerations of resource utilization at a lunar base, the best lunar soils to use for mineral beneficiation (i.e., most free-mineral fragments) have maturities near the immature/submature boundary (Is/FeO approximately or = 30), not the mature soils with their complications due to extensive agglutination. The particle data obtained from the nine mare soils confirm the generalizations for lunar soils predicted by L.A. Taylor and D.S. McKay (1992, Lunar Planet Sci. Conf. 23rd, pp. 1411-1412 [Abstract]).

Aluminum↗
PubMed1993

Increasing obstetrical care access to the rural poor.

Rising malpractice insurance rates have led to a decrease in the number of physicians who provide rural obstetrical care. North Carolina has responded with the Rural Obstetrical Care Incentive (ROCI) Program, which provides up to $6,500 per year to physicians who provide obstetrical care to the rural poor in conjunction with a local health department. This study finds some evidence that the program has led to an increase in the satisfaction that physician participants feel toward the prenatal care available at the local health department; that participants are increasing their provision of obstetrical care to Medicaid patients compared to other physicians in the state; and that the percentage of women delivering after receiving inadequate prenatal care is decreasing in the original ROCI counties, at a time when other rural counties are experiencing an increase in this measure. Other states should consider the ROCI program as one aspect of a rural health strategy.

Female↗
PubMed1992

Daily rhythmicity of the rat acoustic startle response.

We have measured the acoustic startle response (ASR) amplitude and latency in rats housed in a 12:12 light:dark (LD) cycle. The response amplitudes to eliciting stimuli (ES) of 110 dB or 120 dB (white noise) were significantly higher (nearly two-fold) during D than during L. Similar, but nonsignificant, trends were also observed at ES intensities of 90 dB or 100 dB. While some significant LD ASR latency differences were observed, we cannot ascribe them to the photoperiodic phase at this time. These findings conclusively demonstrate that the mammalian ASR amplitude exhibits daily rhythmicity.

Acoustic Stimulation↗
PubMed1992

The incidence of pacemaker dysfunction during helicopter air medical transport.

A number of recent publications have raised concern regarding in-flight pacemaker dysfunction during air medical transport. Unfortunately the clinical importance of this problem is unknown. The authors' purpose was to examine the incidence of pacemaker use and malfunction during helicopter air medical transport, using an incidence (cohort) study of an air medical service of a tertiary-care teaching hospital. During the study period, April 1, 1987 through December 31, 1991 2,388 patients were air-transported. Cardiac patients constituted 72% of the total population. Pacemakers were used in 44 patients, temporary transvenous pacemakers in 35, permanent transvenous in five, and transcutaneous pacers in four patients. No rate-responsive pacemakers were transported. No episodes of pacemaker malfunction were observed (95% confidence interval 0 to .002 for the population as a whole). The authors conclude that pacemaker dysfunction during air medical transport is a very rare occurrence, in part due to the infrequent transport of patients requiring these devices.

Aged↗
PubMed1992

Circadian modulation of the rat acoustic startle response.

The acoustic startle response (ASR) of male rats was measured during several sessions over a 24-hr period in both a light-dark cycle and a constant-dark condition. Each session consisted of 10 trials each at 80, 90, 100, 110, and 120 dB white noise. The results indicate robust daily and circadian modulation of ASR amplitude that consist of an approximately twofold nocturnal increase at eliciting-stimuli intensities above 80 dB. Similar results were observed in female rats in constant-dark conditions. To determine whether daily changes in auditory thresholds were responsible for the observed modulation, ASR reflex modification procedures were used. These procedures were designed to measure auditory thresholds at frequencies of 10 and 40 kHz at several times of day. The results suggest a lack of significant circadian differences in auditory thresholds at these frequencies. This study demonstrates a novel role of the rat circadian system in the modulation of ASR amplitude.

Acoustic Stimulation↗
PubMed1991

Microbial metabolic activities in soils of old-field communities following eleven years of nutrient enrichment.

Effects of 11 years (1978-1988) of nutrient enrichment (fertilizer or sludge) on microbial metabolic activity in soil samples collected from contrasting types of old-field communities were studied during September 1989. During the 1989 growing season, subplots were manipulated by tilling and/or liming to evaluate mechanisms of ecosystem recovery or were left undisturbed. Metabolic activities of soil microorganisms were determined by measuring dehydrogenase activity within soil samples collected from these subplots. The amounts of 2,3,5-triphenyltetrazolium formazan formed during incubation by the reduction of 2,3,5-triphenyltetrazolium chloride were used to evaluate dehydrogenase activity. Plots that had received long-term applications of sludge or fertilizer had significantly lower rates of microbial activity (P<0.05) than did control plots. Fertilizer and sludge plots treated with lime had significantly higher microbial metabolic activity (P<0.05) than those not receiving lime. Whereas liming stimulated microbial activity to near control levels, tilling had no significant treatment effect.

Journal Article↗
PubMed1990

Physiologically based pharmacokinetic modeling of the lactating rat and nursing pup: a multiroute exposure model for trichloroethylene and its metabolite, trichloroacetic acid.

A physiologically based pharmacokinetic (PB-PK) model was developed to describe trichloroethylene (TCE) kinetics in the lactating rat and nursing pup. The lactating dam was exposed to TCE either by inhalation or by ingestion in drinking water. The nursing pup's exposure to TCE was by ingestion of maternal milk containing TCE. The kinetics of trichloroacetic acid (TCA), a metabolite of TCE, were described in the lactating dam and developing pup by a hybrid one-compartment model. The lactating dam's exposure to TCA was from metabolism of TCE to TCA. The pup's exposure to TCA was from metabolism of TCE ingested in suckled milk and from direct ingestion of TCA in maternal milk. For the PB-PK model, partition coefficients (PCs) were determined by vial equilibration, and metabolic constants for TCE oxidation, by gas uptake methods. The blood/air and the fat/blood PCs for the dam were 13.1 and 34.2, and for the pup, 10.6 and 42.3, respectively. The milk/blood PC for the dam was 7.1. In lactating rats and rat pups (19-21 days old) the maximum velocities of oxidative metabolism were 9.26 +/- 0.073 and 12.94 +/- 0.107 mg/kg/hr. The plasma elimination rate constant (K = 0.063 +/- 0.004 hr-1) and apparent volume of distribution (Vd = 0.568 liter/kg) for TCA in the lactating dam were estimated from both intravenous dosing studies and an inhalation study with TCE. For the pup, K (0.014 +/- hr-1) and Vd (0.511 liter/kg) were estimated from a single 4-hr inhalation exposure with TCE. The dose-rate-dependent stoichiometric yield of TCA from oxidative metabolism of TCE in the lactating rat is 0.17 for a low-concentration inhalation exposure (27 ppm TCE) and 0.27 for an exposure above metabolic saturation (about 600 ppm TCE). For the pup, the stoichiometric yield of TCA is 0.12. With changing physiological values during lactation for compartmental volumes, blood flows, and milk yields obtained from the published literature and kinetic parameters and PCs determined by experimentation, a PB-PK model was constructed to predict maternal and pup concentrations of TCE and TCA. To test the fidelity of the PB-PK lactation model, a multiday inhalation exposure study was conducted from Days 3 to 14 of lactation and a drinking water study, from Days 3 to 21 of lactation. The inhalation exposure was 4 hr/day, 5 days/week, at 610 ppm. The TCE concentration in the drinking water was 333 micrograms/ml. Prediction compared favorably with limited data obtained at restricted time points during the period of lactation.

Animals↗
PubMed1990

Comparison of Albendazole and Praziquantel therapy of Echinococcus granulosus in naturally infected sheep.

The effects of albendazole (10 mg kg-1 day-1) and praziquantel (50 mg kg-1 day-1) for 6 weeks on naturally infected sheep with pulmonary cysts of Echinococcus granulosus of proven viability were studied. Immediately following therapy, one of three sheep treated with praziquantel had viable cysts and 7 months later one of two sheep had viable cysts. One sheep died during albendazole therapy, but 7 months following therapy only one of five sheep had viable cysts. Electron microscopy demonstrated necrotic germinal layer tissue in most albendazole-treated cysts and praziquantel also had an effect on cyst ultrastructure. These data suggest that recurrence in humans treated with albendazole may be small. Whilst praziquantel was not particularly effective in this animal model, its clear effect on the ultrastructure suggests that an increased dose and combination therapy with albendazole may be more effective.

Albendazole↗
PubMed1990

Echinococcus granulosus: development of resistance to albendazole in an animal model.

Gerbils with well developed peritoneal cysts of Echinococcus granulosus were randomized to albendazole 50 mg/kg/day or untreated control. Treated animals had less disease at post mortem after 3 months of treatment. Cysts were then taken from both albendazole-treated and control animals and cultured in vitro either with or without albendazole sulphoxide (Alb Sx) 500 micrograms/L for 14 days. Viability of cysts was then established by implantation of whole cysts into gerbils. Whilst naive cysts were affected by Alb Sx (only 2 cysts developed/gerbil) cysts from animals treated with albendazole were not sensitive to further therapy (6.4 cysts/gerbil).

Albendazole↗
PubMed1990

Perioperative prophylactic chemotherapy of Echinococcus granulosus: determination of minimum effective length of albendazole therapy in in vitro protoscolex culture.

Protoscoleces of Echinococcus granulosus were cultured in vitro in 500, 250 or 100 micrograms/l albendazole sulphoxide for 1,3,7,10,14d and then 'rescued' (R) into drug-free medium for the remainder of the culture period. Successful minimum lengths of therapy were much longer than for praziquantel, and only at 500 micrograms/l was the 10dR treatment as effective as continuous therapy for 28d. Treatment with 100 micrograms/l both in continuous culture and in the 'R' experiments was ineffective over a 35d period. The results are compared with those from similar experiments using praziquantel.

Albendazole↗
PubMed1989

Maternal exposure to 1,1,2-trichloroethylene affects myelin in the hippocampal formation of the developing rat.

The effect of 1,1,2-trichloroethylene (TCE), an industrial solvent, on myelin in the dorsal hippocampus of the developing rat was investigated. Rat pups were exposed to TCE via their dams' drinking water while in utero and until they were sacrificed at 21 days of age. Frozen coronal sections through the dorsal hippocampus were stained for the presence of myelin using a modification of the Heidenhain procedure developed for frozen sections. A significant decrease in myelinated fibers was found in the stratum lacunosum-moleculare, an area comprised of distal dendritic profiles of CA1 pyramidal neurons which receive input from the entorhinal cortex. These findings suggest that the reduction in myelin in the hippocampus may be responsible, in part, for behavioral effects observed following TCE exposure.

Animals↗