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Biomedical subjects

A Mills

Publications and source records attributed to A Mills.

At least 55 records · Page 3Linked to original sources
PubMed1997

Modern oral contraceptives and cardiovascular disease.

We reviewed evidence that bears on the cardiovascular safety of combined oral contraceptives containing second- and third-generation progestogens and < 50 micrograms of estrogen. Recent epidemiologic studies indicate that current use of these formulations is associated with a smaller increase in the incidence of venous thromboembolism than earlier formulations. In some studies the increase for third-generation formulations containing desogestrel or gestodene was about 1.5 to 2 times that for second-generation formulations, but there is evidence that differences between users in underlying risk and likelihood of being diagnosed contributed to this result. Recent studies of myocardial infarction suggest a smaller increase in risk associated with modern formulations than with earlier ones; one study suggests a threefold increase for second-generation formulations and no increase for third-generation formulations, but the finding requires confirmation. Recent studies of stroke indicate little or no increase in risk for modern formulations among women without risk factors. We conclude that modern combined oral contraceptives are safer than earlier formulations with respect to cardiovascular disease, which occurs rarely in young women.

Cardiovascular Diseases↗
PubMed1997

The cost-effectiveness of permethrin impregnated bednets in preventing child mortality in Kassena-Nankana district of Northern Ghana.

Permethrin impregnated bednets are now being widely promoted as an effective means of protecting African children against malaria, but there is little evidence of their cost-effectiveness. The impact on child mortality of introducing permethrin impregnated bednets was evaluated in a rural district of northern Ghana in a controlled trial. The cost-effectiveness of the intervention is reported in this paper. The total cost of the intervention over the 2 years of follow-up was US $148,245. Cost per impregnated bednet per year and per person protected per year was US $2.4 and 1.2, respectively. Approximately 16,800 child years were protected and 74 child deaths averted at an estimated cost of US $8.8 per child year protected and US $2003 per death averted. In this rural community, where life expectancy at the mean age of death of trial children was 57.5 years, the estimated cost per discounted healthy life-year gained was US $73.5. Sensitivity analysis suggested that this cost-effectiveness ratio might be reduced substantially by feasible changes in programme implementation. This study supports the argument that the cost-effectiveness of bednet impregnation is sufficiently attractive to make it part of a package of high priority interventions for children. Issues of how to finance the provision of nets and insecticide, and especially the relative contribution of governments, households and donors, need urgently to be addressed.

Bedding and Linens↗
PubMed1997

The poor pay more: health-related inequality in Thailand.

This paper examines the equality of utilization for equal need and equity of out-of-pocket expenditure for health services in a large urban area in Thailand. Data from a household health interview survey were used to explore patterns of perceived morbidity, utilization of various treatment sources, and out-of-pocket payment. Financial access to health care, as reflected in medical benefit/ insurance cover, appeared to influence reported illness and hospitalization rates. Gross lack of access to health care amongst lower socio-economic groups was not the main problem in this densely populated urban area because people could choose and use alternative health services according to their ability and willingness to pay. The corollary, however, was an inequitable pattern of out-of-pocket health expenditure by income quintile and per capita. The underprivileged were more likely to pay out of their own pocket for their health problems, and to pay out of proportion to their household income when compared with more privileged groups. Furthermore, the underprivileged were least likely to be covered by government health benefit schemes, in contrast in particular to civil servants, who paid less out of pocket and did not contribute to their medical benefit fund. The private health sector (private clinics and private hospitals) was the major provider of health care to urban dwellers for both outpatient and inpatient services. Policy options for the short and long term to improve the equity of payment systems for health care are discussed.

Financing, Personal↗
PubMed1997

Leopard or chameleon? The changing character of international health economics.

Over the last 25 years the discipline of health economics has developed substantially. As an applied discipline, it has adapted and changed over time in response to the changing concerns of policy-makers, planners and managers. This paper questions whether it is like a chameleon, changing its appearance in response to the external environment, or like the leopard that never changes its spots. In answering the question, the paper presents an overview of the development of health economics as it has been applied in low and middle income countries distinguishing three eras, the 1970s, 1980s, and 1990s, and argues that in each of these eras the preoccupations of health economists have been somewhat different. In each era the key contributions of health economics are identified. The paper ends by considering future research priorities, and the obligations of developed country institutions in terms of research topics and mode of work.

Cost-Benefit Analysis↗
PubMed1997

Improving the efficiency of district hospitals: is contracting an option?

A world-wide revolution in thinking about public sector management has occurred in recent years, termed the 'new public management'. It aims to improve the efficiency of service provision primarily through the introduction of market mechanisms into the public sector. The earliest form of marketization in developed countries has tended to be the introduction of competitive tendering and contracts for the provision of public services. In less wealthy countries, the language of contracting is heard with increasing frequency in discussions of health sector reform despite the lack of evidence of the virtues (or vices) of contracting in specific country settings. This paper examines the economic arguments for contracting district hospital care in two rather different settings in Southern Africa: in South Africa using private-for-profit providers, and in Zimbabwe using NGO (mission) providers. The South African study compared the performance of three 'contractor' hospitals with three government-run hospitals, analysing data on costs and quality. There were no significant differences in quality between the two sets of hospitals, but contractor hospitals provided care at significantly lower unit costs. However, the cost to the government of contracting was close to that of direct provision, indicating that the efficiency gains were captured almost entirely by the contractor. A crucial lesson from the study is the importance of developing government capacity to design and negotiate contracts that ensure the government is able to derive significant efficiency gains from contractual arrangements. In other parts of Africa, contracts for hospital care are more likely to be agreed with not-for-profit providers. The Zimbabwean study compared the performance of two government district hospitals with two district 'designated' mission hospitals. It found that the two mission hospitals delivered similar services to those of the two government hospitals but at substantially lower unit cost. The nature of the contract between government and missions was implicit rather than explicit and of long standing. On the whole the mission organizations felt the informal nature of the agreement was advantageous, though the government plans to introduce service contracts at district level with all hospitals, both government and mission. The paper concludes by identifying concerns raised by the case-studies that are of relevance to other countries considering the introduction of explicit contractual arrangements for district hospital provision.

Contract Services↗
PubMed1997

The impact of charging for insecticide on the Gambian National Impregnated Bednet Programme.

During the second year of the Gambian National Impregnated Bednet Programme (NIBP) charges for insecticide ($0.50 per net) were introduced into the half of the primary health care villages in the country where insecticide have been provided free of charge the previous year. Free insecticide was provided in the remaining villages that had acted as controls during the previous year. In villages where insecticide was provided free, 77% of nets were treated with insecticide. In contrast, in villages where charges were made coverage was only 14%. During the first year of the NIBP, mortality in children was significantly lower in villages where insecticide was provided free than in the control villages. Introduction of a charge for insecticide into the first group of villages and the provision of free insecticide in the latter abolished this difference. The cash income of rural Gambians is very limited and payment of even $2-3 for insecticide treatment for all the bednets in a household represents a substantial outlay. Further education on the benefits of treatment of nets and/or the provision of cheaper insecticide will be required before the full benefits of this powerful new malaria control measure can be fully realised in the Gambia.

Bedding and Linens↗
PubMed1997

Mutagenesis, biochemical characterization and X-ray structural analysis of point mutants of bovine chymosin.

Chymosin B point mutants, A115T and G243D (chymosin A), were expressed in Escherichia coli and Trichoderma reesei respectively, characterized biochemically, crystallized and studied by X-ray analysis at 2.3 and 2.8 angstroms resolutions respectively. The three-dimensional structures showed that the mutations gave rise to local conformational changes only when compared with that of chymosin B. Kinetic analysis of the A115T mutant with a six residue synthetic peptide revealed a reduction in Km with respect to the wild type, possibly caused by the small local changes in the vicinity of S1 and S3. Although, kinetic analyses of the G243D mutant using the short substrate showed reduced catalytic activity, use of a 15 residue substrate based on residues 98-112 of kappa-casein, the natural substrate, revealed an increase in the kcat compared with chymosin B, probably a consequence of the charge introduced that may interact with the substrate between P4 and P8.

Amino Acid Sequence↗
PubMed1997

Vulnerable adolescent girls: opposite-sex relationships.

This interview-based study compares the opposite-sex relationships of 50 girls, aged 15-16, identified as being at risk for difficulties in early adult partnerships, with 50 girls of the same age from an inner-city school. The high-risk girls had begun solo-dating earlier than the school girls, were more likely to have had a sexual relationship, to have had more sexual partners, to have been pregnant, and to have had a child. A third of the girls in both groups were solo-dating at the time of the interview. In contrast to the school girls, the high-risk girls attached a prominence and permanence to their current dating relationships, which already bore the hallmarks of later unsupportive partnerships.

Adolescent↗
PubMed1997

Diffuse oesophageal spasm: diagnosis by ambulatory 24 hour manometry.

BACKGROUND: Diffuse oesophageal spasm (DOS) is a potential cause of intermittent chest pain and/or dysphagia. In the past, the diagnosis of DOS has relied on criteria obtained from standard oesophageal manometry (more than one simultaneous contraction in a series of 10 wet swallows with the rest being peristaltic). As symptoms are intermittent, however, 24 hour manometry may well be more suited to its investigation. AIMS: To determine the ability of 24 hour manometry to detect the symptomatic contractions of DOS and to compare standard, laboratory based manometry with 24 hour manometry in its diagnosis. PATIENTS: Three hundred and ninety consecutive patients referred with suspected oesophageal disorders. METHODS: Standard laboratory based manometry and 24 hour outpatient manometry. RESULTS: Sixteen patients were classified by 24 hour manometry as having DOS on the basis of painful contractions (spasms) of excessive duration and increased amplitude. Laboratory based manometry failed to detect the majority of these patients with DOS (14/16), and 53/55 were incorrectly labelled as having DOS on the basis of asymptomatic manometric findings. CONCLUSION: The detection of symptomatic DOS requires 24 hour manometry.

Adult↗
PubMed1996

Economic analysis at the global level: a resource requirement model for HIV prevention in developing countries.

Agencies operating at the international level have a need for economic analysis to help develop global health policies and determine resource requirements to support their advocacy efforts. This paper presents work commissioned by the Global Programme on AIDS to estimate the total resource requirements of implementing a package of HIV prevention strategies in developing countries. The modelling approach identified a hypothetical package which should be implemented and developed a set of assumptions relating the size, number and coverage of programmes required for each strategy to a set of demographic and other characteristics of individual countries. Costs were attached to estimate the total costs of the package for individual countries, regions and the developing world. Results are presented for regions and their implications discussed. Conclusions are drawn on the value of this type of modelling approach to estimating resource requirements.

Budgets↗
PubMed1996

Effect of methadone on the biophysical profile.

OBJECTIVE: To determine the effect of methadone on the biophysical profile. STUDY DESIGN: Sixteen narcotics-dependent gravidas on methadone maintenance were selected for the study. Biophysical profiles and nonstress tests (NSTs) were performed on women between 28 and 40 weeks' estimated gestational age before and two hours after methadone was given. The reactivity of the nonstress tests, biophysical profile scores and time needed to complete the biophysical profiled before and after methadone dosing were compared. RESULTS: Significantly more NSTs were nonreactive after methadone (P < .001), and it took more time for the NST to become reactive (P < .01). Although it took longer for the modified biophysical profile to be completed after methadone dosing, with the mean time going from 3.8 to 19.8 minutes (P < .01), the scores were the same before and after methadone in 75% of the women, with the mean score not significantly different before or after methadone. CONCLUSION: Our results suggest that the modified biophysical profile is a clinically useful test in the methadone-maintained gravida.

Adult↗
PubMed1995

Autoradiographic mapping of [3H]sumatriptan binding in cat brain stem and spinal cord.

In vitro autoradiography was performed on sections of cat brain stem and spinal cord using [3H]sumatriptan. Localization studies using 20-25 nM [3H]sumatriptan showed specific binding to cells in the trigeminal nucleus caudalis and nucleus tractus solitarius of the brain stem and the dorsal horn of the spinal cord. This binding was unaffected by 8-hydroxy-dipropylaminotetralin (20 nM), but was abolished by 5-carboxamidotryptamine (200 nM). Ketanserin displaced total specific binding in the brain stem with a pIC50 of 6.2 but no apparent regional specificity. These results indicate that [3H]sumatriptan labels predominantly 5-HT1D alpha and/or 5-HT1D beta (but not 5-HT1A or 5-HT1F) receptor subtypes in cat brain stem and spinal cord.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Registration and immobilization in robot-assisted surgery.

Robotic systems for computer-assisted surgery involve both tools and techniques that are new to the surgical arena. Registration and immobilization in particular are key problems. Registration is the spatial alignment of the coordinate frames of the robot, an anatomic object (e.g., a bone), and the preoperative plan (a computer model). Immobilization is necessary to maintain that alignment. We discuss various approaches to registration and immobilization and solutions appropriate for an orthopedic surgical system.

Ankle Joint↗
PubMed1995

Oesophageal acid clearance in patients with severe reflux oesophagitis.

Previous studies examining oesophageal acid clearance have employed a variety of techniques to induce or simulate acid reflux. Clearance abnormalities have been deduced from abnormal standard motility studies, barium radiology or from 24-h pH recordings. In this study a 24-h pH and oesophageal motility recording system was used to study naturally occurring acid reflux episodes in control subjects and in two groups of patients with severe acid reflux disease (erosive oesophagitis and oesophageal stricture). Acid clearance was compared between the subject groups. Patients with oesophageal stricture were found to have poor oesophageal peristaltic ability and particularly poor oesophageal acid clearance. Those with erosive oesophagitis had normal peristaltic swallowing but abnormal acid clearance. This study has characterized, for the first time, the abnormalities in acid clearance during naturally occurring acid reflux episodes in patients with severe reflux disease. A more complete understanding of these clearance abnormalities could influence future medical and surgical strategies in the management of severe gastro-oesophageal reflux disease.

Adult↗