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Biomedical subjects

D Hughes

Publications and source records attributed to D Hughes.

At least 145 records · Page 8Linked to original sources
PubMed1996

Application of a classical model of competitive business strategy to orthodontic practice.

This study explored how market forces might affect the business aspects of orthodontic practices; in particular, profitability. The forces identified were (1) intensity of rivalry, (2) threat of new entrants, and (3) bargaining power of buyers and suppliers. A mail survey instrument was used to collect the data. Results showed that more than half the surveyed practices show an increase in new case starts despite weak economic conditions. Although satellite offices and marketing increase the overhead, they do not add to net profit. New entrants are a threat to existing practices, as are the substitute discretionary spending by the consumer. Interestingly, while some orthodontic practices have joined the managed care programs, a majority of them realize neither increased patient load nor profit. Our data seem to indicate that orthodontic practices have not been successful in "cost containment" with their marketing, number of employees, computerization or inventory. Collectively, the results of this study suggest that success in an orthodontic office is primarily dependent on the practitioner's personality traits, rather than rigidly applied business principles.

Attitude of Health Personnel↗
PubMed1996

A cost minimization study comparing vigabatrin, lamotrigine and gabapentin for the treatment of intractable partial epilepsy.

Epilepsy is one of the commonest of the serious neurological disorders. The total economic burden of epilepsy in the United Kingdom has been estimated to be 1930 m pounds, with around 32 m pounds spent on antiepileptic drug therapy alone. Despite the high level of expenditure on drug therapy for epilepsy there is very little information regarding the relative cost-effectiveness of the different drugs available. It is important to establish the relative cost-effectiveness of therapies to provide decision makers with the information necessary to allocate resources in a rational manner and thus achieve the highest benefit for available resources. In this study the cost-effectiveness of lamotrigine, vigabatrin and gabapentin was estimated by a cost minimization analysis for the first year of drug therapy using data based on published studies. In general, there was little difference between the initial direct costs of treatment, however, the fewer side-effects associated with gabapentin is reflected in the lower total costs of treatment in the first year resulting in savings of 18.52 pounds per patient compared with lamotrigine and 47.18 pounds compared with vigabatrin. Based on incidence data estimates this translates to estimated direct cost savings to the UK of between 166,680 pounds and 424,620 pounds per annum.

Acetates↗
PubMed1996

Randomized trial of bolus phenylephrine or ephedrine for maintenance of arterial pressure during spinal anaesthesia for Caesarean section.

Thirty-eight healthy women undergoing elective Caesarean section under spinal anaesthesia at term were allocated randomly to receive boluses of either phenylephrine 100 micrograms or ephedrine 5 mg for maintenance of maternal arterial pressure. The indication for administration of vasopressor was a reduction in systolic pressure to < or = 90% of baseline values. Maternal arterial pressure (BP) and heart rate (HR) were measured every minute by automated oscillometry. Cardiac output (CO) was measured by cross-sectional and Doppler echocardiography before and after preloading with 1500 ml Ringer lactate solution and then every 2 min after administration of bupivacaine. Umbilical artery pulsatility index (PI) was measured using Doppler before and after spinal anaesthesia. The median (range) number of boluses of phenylephrine and ephedrine was similar; 6 (1-10) vs 4 (1-8) respectively. Maternal systolic BP and CO changes were similar in both groups, but the mean [95% CI] maximum percentage change in maternal HR was larger in the phenylephrine group (-28.5 [-24.2, -32.9]%) than in the ephedrine group (-14.4 [-10.6, -18.2]%). As a consequence atropine was required in 11/19 women in the phenylephrine group compared with 2/19 in the ephedrine group (P < 0.01). Mean umbilical artery pH [95% CI] was higher in the phenylephrine group (7.29 [7.28-7.30]) than in the ephedrine group (7.27 [7.25-7.28]). The results of the present study support the use of phenylephrine for maintenance of maternal arterial pressure during spinal anaesthesia for elective Caesarean section.

Adult↗
PubMed1996

The cost-effectiveness of family planning service provision.

BACKGROUND: Family planning services are amongst the most highly utilized services in the National Health Service. There have, however, been few empirical studies of the cost-effectiveness of these services. METHODS: Two measures of output were used to calculate the cost-effectiveness of family planning services. The first measure is based on the number of pregnancies averted. The second measure uses the couple year of protection as the measure of output. Accordingly, two cost-effectiveness ratios are calculated: cost per pregnancy averted and cost per couple year of protection. RESULTS: The direct cost per pregnancy averted is between 48 pounds and 167 pounds for reversible and 18 pounds and 21 pounds for non-reversible methods. The cost per couple year of protection is between 49 pounds and 184 pounds for reversible and 17 pounds and 21 pounds for non-reversible methods. For both approaches, if averted NHS costs associated with family planning services are included these translate into resource savings to the NHS resulting from the provision of these services. CONCLUSION: From the perspective adopted in this study, family planning services are highly cost-effective. According to calculations made in this paper, these services provide a high rate of return to the NHS and, when the resource consequences of unplanned pregnancies in the health sector as a whole are considered, result in resource savings.

Cost Savings↗
PubMed1996

MR imaged neurovascular relationships at the cerebellopontine angle.

Improvements in MR imaging techniques allow visualisation of the anatomy of the cerebellopontine angle (CPA) in increasingly accurate detail, revealing the complex interrelationship of the neurovascular structures in this region. We wished to assess whether vessels and vascular loops intimately associated with cranial nerves VII and VIII, corresponded to any abnormality or symptom pattern, and thus had any clinical significance. The MR scans of 108 patients were retrospectively reviewed and the imaging status of VII, VIII, the vessels, presence of vascular loops and their relationship to the nerves, coded and recorded. The patients' records were independently reviewed and the presence and "sidedness' of asymmetrical hearing loss, tinnitus, vertigo, and the results of caloric and brain stem evoked responses recorded. The vessels were closely associated with VII and VIII in over 30% of this sample with vascular loops imaged in 21% of patients, and clearly imaged entering the IAM in 7% of both right and left CPAs studied. There was no statistically significant relationship demonstrated between the proximity of the vessels, or vascular loops, to the nerves and a symptom, or symptom pattern. These findings should be considered a normal variant on MR scanning.

Adult↗
PubMed1996

Accuracy of four commercial systems for identification of Burkholderia cepacia and other gram-negative nonfermenting bacilli recovered from patients with cystic fibrosis.

Burkholderia cepacia has recently been recognized as an important pathogen in chronic lung disease in patients with cystic fibrosis (CF). Because of the social, psychological, and medical implications of the isolation of B. cepacia from CF patients, accurate identification of this organism is essential. We compared the accuracies of four commercial systems developed for the identification of nonfermenting, gram-negative bacilli with that of conventional biochemical testing for 150 nonfermenters including 58 isolates of B. cepacia recovered from respiratory secretions from CF patients. The accuracies of the four systems for identifying all nonfermenters ranged from 57 to 80%, with the RapID NF Plus system being most accurate. The accuracies of these systems for identifying B. cepacia ranged from 43 to 86%, with the Remel system being most accurate. Depending on the commercial system, from two to seven isolates were misidentified as B. cepacia. The relatively poor performance of the commercial systems requires that identification of certain nonfermenters be confirmed by conventional biochemical testing. These organisms include B. cepacia, Burkholderia sp. other than B. cepacia, and infrequently encountered environmental species (Pseudomonas and Flavobacterium species). In addition, conventional biochemical testing should be done if a commercial system fails to assign an identification to an organism. Confirmatory testing should preferably be performed by a reference laboratory with experience in working organisms isolated from CF patients.

Bacteriological Techniques↗
PubMed1996

The cost-effectiveness of condoms in the prevention of HIV infection in England and Wales: should condoms be available on prescription?

OBJECTIVES: HIV and AIDS represent a considerable challenge to the British National Health Service, and the resources devoted to treatment and prevention of HIV/AIDS are significant and likely to increase. The focus of recent campaigns promoting safer sexual practices to prevent the spread of HIV have focused on the use of condoms, since condom use reduces the probability of infection. Furthermore, it has also been suggested that condoms should be provided routinely on prescription by general practitioners (GPs). The objective of this study was to evaluate the cost-effectiveness of GP-provision of condoms in the prevention of HIV infection. Since risk factors for HIV infection differ across population groups, cost-effectiveness ratios for three at-risk groups were considered. METHODS: Estimates of the cost per infection prevented and the cost per life year gained were made for female heterosexuals, male heterosexuals, and male homosexuals in England and Wales. Sensitivity analysis was conducted on a number of key parameters. RESULTS: The costs per infection prevented were 2,327,744 Pounds for female heterosexuals, 9,709,987 Pounds for male heterosexuals and 1315 Pounds for male homosexuals. The corresponding costs per life year gained were 56,774 Pounds, 269,722 Pounds and 37 Pounds. When savings from the costs of care were taken into account the use of condoms resulted in cost savings of nearly 50,000 Pounds for homosexual males. CONCLUSIONS: The provision of GP-prescribed condoms is highly cost-effective for male homosexuals. Such provision is much less cost-effective for heterosexuals, primarily due to the relatively low prevalence of HIV in the heterosexual population and the low infectivity parameter. This suggests that routine GP-provision of condoms would be inappropriate for all at-risk groups, and should target high-risk groups, specifically male homosexuals.

Condoms↗
PubMed1996

Cholesterol levels among Japanese Americans and other populations: Seattle Nikkei Health Study.

The purpose of this study was to compare average cholesterol levels between Seattle based Japanese Americans and three other populations: U.S. population, native Japanese population and native Japanese urban workers. A total of 1,466 Japanese Americans (724 men and 742 women) participated in cardiovascular disease screening in the Seattle area during 1989 94. Data sources for comparisons are from the Third National Health and Nutrition Examination Survey for 1988-91, the results of the National Cardiovascular Disease Examination Survey in Japan for 1990, and cardiovascular disease screening conducted by the Epidemiological Arteriosclerosis Research Institute in Japan for 1989. Total cholesterol and triglyceride levels of Seattle Japanese American men and women were highest among the four populations. Among men, high density lipoprotein cholesterol (HDL-C) levels for Seattle Japanese Americans and native Japanese were similar and fell between those of urban Japanese workers and the U.S. population. In women, the average HDL C levels were highest in the Japanese urban workers, second highest in Seattle Japanese Americans, and lowest in both the U.S. population and native Japanese population. These differences in lipid levels may be caused by both genetic and environmental factors, which are now under investigation.

Adult↗
PubMed1996

Proteinuria in recipients of liver transplants.

We investigated the incidence and significance of proteinuria in recipients of liver transplants. The overall incidence of proteinuria was 59.72%. The peak incidence of proteinuria was at 3 months and at the end of 1 yr posttransplant. Proteinuria was higher in those patients who developed posttransplant diabetes mellitus, and those who developed both posttransplant diabetes and posttransplant hyperlipidemia. Patients who received higher total dosage of steroids and CsA had significantly greater proteinuria. Patients who had a Cr Cl greater than 50 ml/min had greater proteinuria posttransplant for the first 6 months, but the trend was reversed later. We did not find any association of proteinuria with age, weight, rejection episodes, or with the etiology of liver failure. Hypertension was a common occurrence in our patients, and therefore its significance in the causation of proteinuria could not be defined.

Adolescent↗
PubMed1996

Metabolic problems in recipients of liver transplants.

We analyzed the metabolic problems in recipients of liver transplants. Immunosuppression consisted of cyclosporine, steroids and azathioprine. With a mean follow up of 3.5 yr, 37% of 71 recipients were rendered permanently diabetic and hyperlipidemic. Recipients who developed posttransplant diabetes had higher cholesterol levels and proteinuria, but decreased creatinine clearance. Transplant recipients who developed posttransplant hyperlipidemia had greater proteinuria, but their sugars and creatinine clearance were comparable to those who did not have hyperlipidemia. The most significant factor responsible for these metabolic complications was the total dosage of prednisone and cyclosporine. There was no effect of risk antigens on the development of diabetes.

Adult↗
PubMed1996

Complications of 32% dextran-70 in 10% dextrose. A case report.

BACKGROUND: Thirty-two percent dextran-70 in 10% dextrose is a useful distention medium for hysteroscopic surgery. However, the side effects profile is considerable. CASE REPORT: A young woman underwent hysteroscopic evaluation for menorrhagia. Postoperatively, she suffered severe noncardiogenic pulmonary edema, disseminated intravascular coagulopathy and acute anuric renal failure. CONCLUSION: Precautions must be taken when using 32% dextran-70 in 10% dextrose to avoid its potentially life-threatening complications.

Acute Disease↗
PubMed1995

Clinical features of early onset, familial Alzheimer's disease linked to chromosome 14.

Early onset familial Alzheimer's disease (AD) has an autosomal dominant mode of inheritance. Two genes are responsible for the majority of cases of this subtype of AD. Mutations in the beta-amyloid precursor protein (beta APP) gene on chromosome 21 have been shown to completely cosegregate with the disease. We and others have previously described the clinical features of families with beta APP mutations at the codon 717 locus in an attempt to define the phenotype associated with a valine to isoleucine (Val-->Ile) or a valine to glycine (Val-->Gly) change. More recently, a second locus for very early onset disease has been localized to chromosome 14. The results of linkage studies in some families suggesting linkage to both chromosomes have been explained by the suggestion of a second (centromeric) locus on chromosome 21. Here we report the clinical features and genetic analysis of a British pedigree (F74) with early onset AD in which neither the beta APP locus nor any other chromosome 21 locus segregates with the disease, but in which good evidence is seen for linkage on the long arm of chromosome 14. In particular we report marker data suggesting that the chromosome 14 disease locus is close to D14S43 and D14S77. Given the likelihood that F74 represents a chromosome 14 linked family, we describe the clinical features and make a limited clinical comparison with the beta APP717 Val-->Ile and beta APP717 Val-->Gly encoded families that have been previously described.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

A new mutation in 16S rRNA of Escherichia coli conferring spectinomycin resistance.

We report a novel mutation, C1066U in 16S rRNA which was selected for resistance to spectinomycin, an antibiotic which inhibits ribosomal translocation. The minimal inhibitory concentration (MIC) of spectinomycin determined for this mutant (15 micrograms/ml) is greater than with the wild-type plasmid (5 micrograms/ml) but lower than with the well known C1192U mutation (> 80 micrograms/ml). The C1066U mutation also increases the cells sensitivity to fusidic acid, another antibiotic which inhibits translation at the translocation stage, whereas C1192U is unchanged relative to the wild type. We discuss why the acquisition of resistance to one of these drugs is often associated with hypersensitivity to the other.

Base Sequence↗