Airway remodeling measured by multidetector CT is increased in severe asthma and correlates with pathology

BACKGROUND

To prospectively apply an automated, quantitative three-dimensional approach to imaging and airway analysis to assess airway remodeling in asthma patients.

METHODS

Using quantitative software (Pulmonary Workstation, version 0.139; VIDA Diagnostics; Iowa City, IA) that enables quantitative airway segment measurements of low-dose, thin-section (0.625 to 1.25 mm), multidetector-row CT (MDCT) scans, we compared airway wall thickness (WT) and wall area (WA) in 123 subjects participating in a prospective multicenter cohort study, the National Institutes of Health Severe Asthma Research Program (patients with severe asthma, n = 63; patients with mild-to-moderate asthma, n = 35); and healthy subjects, n = 25). A subset of these subjects underwent fiberoptic bronchoscopy and endobronchial biopsies (n = 32). WT and WA measurements were corrected for total airway diameter and area: WT and WA, respectively.

RESULTS

Subjects with severe asthma had a significantly greater WT% than patients with mild-to-moderate asthma and healthy subjects (17.2 +/- 1.5 vs 16.5 +/- 1.6 [p = 0.014] and 16.3 +/- 1.2 [p = 0.031], respectively) and a greater WA percentage (WA%) compared to patients with mild-to-moderate asthma and healthy subjects (56.6 +/- 2.9 vs 54.7 +/- 3.3 [p = 0.005] and 54.6 +/- 2.4 [p = 0.003], respectively). Both WT% and WA% were inversely correlated with baseline FEV(1) percent predicted (r = -0.39, p < 0.0001 and r = -0.40, p < 0.0001, respectively) and positively correlated with response to a bronchodilator (r = 0.28, p = 0.002 and r = 0.35, p < 0.0001, respectively). The airway epithelial thickness measure on the biopsy sample correlated with WT% (r = 0.47; p = 0.007) and WA% (r = 0.52; p = 0.003). In the same individual, there is considerable regional heterogeneity in airway WT.

CONCLUSION

Patients with severe asthma have thicker airway walls as measured on MDCT scan than do patients with mild asthma or healthy subjects, which correlates with pathologic measures of remodeling and the degree of airflow obstruction. MDCT scanning may be a useful technique for assessing airway remodeling in asthma patients, but overlap among the groups limits the diagnostic value in individual subjects.

Software for calculating blood lactate endurance markers

Blood lactate markers are used as summary measures of the underlying model of an athlete's blood lactate response to increasing work rate. Exercise physiologists use these endurance markers, typically corresponding to a work rate in the region of high curvature in the lactate curve, to predict and compare endurance ability. A short theoretical background of the commonly used markers is given and algorithms provided for their calculation. To date, no free software exists that allows the sports scientist to calculate these markers. In this paper, software is introduced for precisely this purpose that will calculate a variety of lactate markers for an individual athlete, an athlete at different instants (e.g. across a season), and simultaneously for a squad.

Pathological Correlates of Late Drug-Eluting Stent Thrombosis

Background— Late stent thrombosis (LST) after Cypher and Taxus drug-eluting stent placement has emerged as a major concern. Although the clinical predictors of LST have been reported, specific morphological and histological correlates of LST remain unknown.

Methods and Results— From a registry totaling 81 human autopsies of drug-eluting stents, 46 (62 lesions) had a drug-eluting stent implanted >30 days. We identified 28 lesions with thrombus and compared those with 34 of similar duration without thrombosis using computer-guided morphometric and histological analyses. LST was defined as an acute thrombus within a coronary artery stent in place >30 days. Multiple logistic generalized estimating equations modeling demonstrated that endothelialization was the best predictor of thrombosis. The morphometric parameter that best correlated with endothelialization was the ratio of uncovered to total stent struts per section. A univariable logistic generalized estimating equations model of occurrence of thrombus in a stent section versus ratio of uncovered to total stent struts per section demonstrated a marked increase in risk for LST as the number of uncovered struts increased. The odds ratio for thrombus in a stent with a ratio of uncovered to total stent struts per section >30% is 9.0 (95% CI, 3.5 to 22).

Conclusions— The most powerful histological predictor of stent thrombosis was endothelial coverage. The best morphometric predictor of LST was the ratio of uncovered to total stent struts. Heterogeneity of healing is a common finding in drug-eluting stents with evidence of LST and demonstrates the importance of incomplete healing of the stented segment in the pathophysiology of LST.

Developing services for the carers of young adults with early-onset psychosis - implementing evidence-based practice on psycho-educational family intervention

This paper describes a series of practice and service development initiatives to incorporate the family-inclusive approach into the newly established Early Intervention in Psychosis Service in Berkshire, England. Following a local study on carers' experiences and needs from those who cared for a young adult with a first-episode psychosis (FEP), a series of flexible services for this group of carers has been developed incorporating the much-researched psycho-educational family interventions. The findings of our local phenomenological study on the carers for young adults with FEP clearly specified the unique needs of this group of carers and that well-established approaches in family work and carers support facilities may have to be adapted to meet such needs. This paper reports the service development process through which a series of specially designed carers' services were set up for carers caring for a young adult with FEP. These services were developed to address carers' needs for knowledge, skills and support to cope with their caring roles and situation, from the stressful beginning of a potentially long caring journey.

Effects of sequential changes from conventional ventilation to high-frequency oscillatory ventilation at increasing mean airway pressures in an ovine model of combined lung and head injury

BACKGROUND

The objective of this study was to determine the intracranial, cardiovascular and respiratory changes induced by conversion to high-frequency oscillator ventilation from conventional mechanical ventilation at increasing airway pressures.

METHODS

In this study, 11 anaesthetized sheep had invasive cardiovascular and intracranial monitors placed. Lung injury was induced by saline lavage and head injury was induced by inflation of an intracranial balloon catheter. All animals were sequentially converted from conventional mechanical ventilation to high-frequency oscillator ventilation at target mean airway pressures of 16, 22, 28, 34 and 40 cm H(2)O. The mean airway pressure was achieved by adjusting positive end expiratory pressure while on conventional mechanical ventilation, and continuous distending pressures while on high-frequency oscillator ventilation. Cerebral lactate production, oxygen consumption and venous oximetry were measured and analysed in relation to changes in transcranial Doppler flow velocity. Transcranial Doppler profiles together with other physiological parameters were measured at each airway pressure.

RESULTS

Cerebral perfusion pressure was significantly lower during high-frequency oscillator ventilation than during conventional mechanical ventilation (CMV: 45, 34, 22, 6, 9 mmHg vs. HFOV: 33, 20, 19, 5, 5 mmHg at airway pressures mentioned above, P = 0.02). Intracranial pressure and cerebrovascular resistance increased with increasing intrathoracic pressures (P = 0.001). Cerebral metabolic indices demonstrated an initial increase in anaerobic metabolism followed by a decrease in cerebral oxygen consumption progressing to cerebral infarction as intrathoracic pressures were further increased in a stepwise fashion. Arterial PaCO(2) increased significantly after converting from conventional mechanical ventilation to high-frequency oscillator ventilation (P = 0.001). However, no difference was observed between conventional mechanical ventilation and high-frequency oscillator ventilation when intracranial pressure, metabolic and transcranial Doppler indices were compared at equivalent mean airway pressures.

CONCLUSIONS

The use of high positive end expiratory pressure with conventional mechanical ventilation or high continuous distending pressure with high-frequency oscillator ventilation increased intracranial pressure and adversely affected cerebral metabolic indices in this ovine model. Transcranial Doppler is a useful adjunct to intracranial pressure and intracranial venous saturation monitoring when major changes in ventilation strategy are adopted.

Chronic kidney disease and mortality and morbidity among patients with established cardiovascular disease: a West of Ireland community-based cohort study

BACKGROUND

The importance of chronic kidney disease as an independent risk factor for morbidity and mortality in patients with cardiovascular disease in the community is not widely recognized.

METHODS

A retrospective cohort study based in the West of Ireland followed a randomized practice-based sample of patients with cardiovascular disease. A database of 1609 patients with established cardiovascular disease was established in 2000. This was generated from a randomized sample of 35 general practices in the West of Ireland. The primary endpoint was a cardiovascular composite endpoint, which included death from a cardiovascular cause or any of the cardiovascular events of myocardial infarction (MI), heart failure, peripheral vascular disease and stroke. The secondary endpoint was death from any cause.

RESULTS

Of the original community-based cohort of 1609 patients with cardiovascular disease, 1272 (79%) had one or more serum creatinine measurements during the study period and 31 (1.9%) patients were lost to follow-up. Median follow-up was 2.90 years (SD 1.47) and the risk of the cardiovascular composite endpoint (total of 219 events) was significantly increased in those patients with reduced estimated glomerular filtration rate (GFR) [log rank (Mantel-Cox) 26.74, P<0.001] as was the risk of death from any cause (total of 214 deaths) [Log Rank (Mantel-Cox) 56.97, P<0.001]. On the basis of the proportional hazards model, while adjusting for other significant covariates, reduced estimated GFR was associated with a significant increase in risk of the primary and secondary outcomes (P<0.01). For every 10 ml decrement in estimated GFR there was a corresponding 20% increase in hazard of the cardiovascular composite endpoint and a 33% increase in hazard of death from any cause.

CONCLUSIONS

Estimated GFR appears to discriminate prognosis between patients with established cardiovascular disease. These results emphasise the importance of recognising chronic kidney disease as a significant risk factor in patients with cardiovascular disease in the community.

Who eats four or more servings of fruit and vegetables per day? Multivariate classification tree analysis of data from the 1998 Survey of Lifestyle, Attitudes and Nutrition in the Republic of Ireland

Objective

To identify, using the novel application of multivariate classification trees, the socio-economic, sociodemographic and health-related lifestyle behaviour profile of adults who comply with the recommended 4 or more servings per day of fruit and vegetables.

Design

Cross-sectional 1998 Survey of Lifestyle, Attitudes and Nutrition.

Setting

Community-dwelling adults aged 18 years and over on the Republic of Ireland electoral register.

Subjects

Six thousand five hundred and thirty-nine (response rate 62%) adults responded to a self-administered postal questionnaire, including a semi-quantitative food-frequency questionnaire.

Results

The most important determining factor of compliance with the fruit and vegetable dietary recommendations was gender. A complex constellation of sociodemographic and socio-economic factors emerged for males whereas the important predictors of 4 or more servings of fruit and vegetable consumption among females were strongly socio-economic in nature. A separate algorithm was run to investigate the importance of health-related lifestyle and other dietary factors on compliance with the fruit and vegetable recommendations. Following an initial split on compliance with dairy recommendations, a combination of non-dietary behaviours showed a consistent pattern of healthier options more likely to lead to compliance with fruit and vegetable recommendations. There did, however, appear to be a compensatory element between the variables, particularly around smoking, suggesting the non-existence of an exclusive lifestyle for health risk.

Conclusions

Material and structural influences matter very much for females in respect to compliance with fruit and vegetable recommendations. For males, while these factors are important they appear to be mediated through other more socially contextual-type factors. Recognition of the role that each of these factors plays in influencing dietary habits of men and women has implications for the manner in which dietary strategies and policies are developed and implemented.

Incremental Exercise Test Design and Analysis

Physiological variables, such as maximum work rate or maximal oxygen uptake (VO2max), together with other submaximal metabolic inflection points (e.g. the lactate threshold [LT], the onset of blood lactate accumulation and the pulmonary ventilation threshold [VT]), are regularly quantified by sports scientists during an incremental exercise test to exhaustion. These variables have been shown to correlate with endurance performance, have been used to prescribe exercise training loads and are useful to monitor adaptation to training. However, an incremental exercise test can be modified in terms of starting and subsequent work rates, increments and duration of each stage. At the same time, the analysis of the blood lactate/ventilatory response to incremental exercise may vary due to the medium of blood analysed and the treatment (or mathematical modelling) of data following the test to model the metabolic inflection points. Modification of the stage duration during an incremental exercise test may influence the submaximal and maximal physiological variables. In particular, the peak power output is reduced in incremental exercise tests that have stages of longer duration. Furthermore, the VT or LT may also occur at higher absolute exercise work rate in incremental tests comprising shorter stages. These effects may influence the relationship of the variables to endurance performance or potentially influence the sensitivity of these results to endurance training. A difference in maximum work rate with modification of incremental exercise test design may change the validity of using these results for predicting performance, and prescribing or monitoring training. Sports scientists and coaches should consider these factors when conducting incremental exercise testing for the purposes of performance diagnostics.

Incidence of injury in elite Gaelic footballers

The purpose of this study was to undertake a comprehensive prospective epidemiological study of injuries sustained by elite Gaelic Football players over one season. The pattern of injury is strikingly similar across all teams with 47% of all injuries occurring in the final quarter of games and training. Injuries to the lower limb, particularly the hamstrings muscles accounted for the majority of injuries. 65% of players were unable to participate fully in Gaelic Football activity for between one and three weeks as a result of injury. The high incidence of injury especially hamstrings injuries in the latter stages of training and games warrants further investigation.

Using functional data analysis to summarise and interpret lactate curves

John Tukey used the term exploratory data analysis (EDA) to describe a philosophy for analyzing data where graphical and numerical summaries are used to uncover interesting structures. The applied statistician today has a much more sophisticated set of methods to use when applying the EDA philosophy. One such collection of methods is functional data analysis (FDA), which was used to explore the structure of lactate curves. A principal components analysis and plots of the second derivatives provide new intuitive endurance markers which correlates highly with other numerical summaries of lactate curves that have been suggested in the literature.

Development of structure-taste relationships for monosubstituted phenylsulfamate sweeteners using classification and regression tree (CART) analysis

Twenty monosubstituted phenylsulfamates (cyclamates) have been synthesized and have had their taste portfolios determined. These have been combined with 63 compounds already in the literature to give a database of 83 ortho, meta, and para compounds. A training set of 75 compounds was randomly selected leaving eight compounds as a test set. A series of nine predictors determined with Corey-Pauling-Koltun models, calculated from the PC SPARTAN PRO program and Hammett sigma values taken mainly from the literature, have been used to establish structure-taste relationships for these types of sweeteners. The taste panel data for all compounds were categorized into three classes, namely, sweet (S), nonsweet (N), and sweet/nonsweet (N/S), and a novel "sweetness value" or weighting was also calculated for each compound. Linear and quadratic discriminant analysis were first used with the S, N, and N/S data, but the results were somewhat disappointing. Classification and regression tree analysis using the sweetness values for all 75 compounds was more successful, and only 14 were misclassified and six of the eight test set compounds were correctly classified. For the 29 meta compounds, one subset using just two parameters classified 83% of these compounds. Finally, using various methods, predictions were made on the likely tastes of a number of meta compounds and a striking agreement was found between the tree prediction and those given by earlier models. This appears to offer a strong vindication of the tree approach.

Survival ratio plots with permutation envelopes in survival data problems

A new method is proposed, based on a simple ratio plot, which is useful for identifying time intervals or regions in which survival prospects differ between two distinct populations or treatments. In order to investigate whether any observed difference or trend is due to sampling variation or is due to a possible real effect, resampling techniques are used to generate permutation envelopes as reference bands. The method is applicable to the comparison of survival in two populations for both independent and paired survival problems and also to the assessment of the symmetry of a bivariate survival function.

The effect of health status on patients' satisfaction with out-of-hours care provided by a family doctor co-operative

BACKGROUND

Systems for providing primary care outside normal hours have changed significantly in Europe over the last 20 years. The impetus for this change has come almost entirely from the medical profession, and it is important to consider the patients' perspective. Although patient's satisfaction with out-of-hours care has been studied extensively, the effect of patient's health status on satisfaction level has not been examined previously.

OBJECTIVES

The primary objective of this study was to investigate whether health status has an influence on patient satisfaction with out-of-hours care provided by a family doctor co-operative. The secondary objective of this study was to investigate the impact of age, gender, socio-economic status and call outcome on patients' satisfaction with out-of-hours care.

METHODS

All patients contacting the service over a designated 24 day period were forwarded a postal questionnaire. Health status was recorded using the Short Form-12 (SF-12) health survey. Patients' satisfaction was measured by using a version of the McKinley questionnaire.

RESULTS

The response rate was 55% (531 out of 966). Overall satisfaction levels were high, with 88% of patients rating the service as either excellent or good. Logistic regression, modelling for the simultaneous effects of age, gender, socio-economic status, call outcome and health status on overall satisfaction, found that patients with lower physical and mental health status scores were significantly less likely to be satisfied with their out-of-hours care [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07, P = 0.017; and 1.03, 95% CI 1.00-1.06, P = 0.046, respectively]. Patients with higher socio-economic status were also significantly less likely to be satisfied (OR 0.25, 95% CI 0.11-0.55, P = 0.001). Patient's age and gender, and call outcome did not significantly affect overall satisfaction levels.

CONCLUSION

Family doctor co-operatives have significantly altered the way out-of-hours care is delivered. Patients with lower health status are significantly less likely to be satisfied with this new form of out-of-hours care. This finding has important implications for the future planning of out-of-hours primary care services.

Mutation of the COG complex subunit gene COG7 causes a lethal congenital disorder

The congenital disorders of glycosylation (CDG) are characterized by defects in N-linked glycan biosynthesis that result from mutations in genes encoding proteins directly involved in the glycosylation pathway. Here we describe two siblings with a fatal form of CDG caused by a mutation in the gene encoding COG-7, a subunit of the conserved oligomeric Golgi (COG) complex. The mutation impairs integrity of the COG complex and alters Golgi trafficking, resulting in disruption of multiple glycosylation pathways. These cases represent a new type of CDG in which the molecular defect lies in a protein that affects the trafficking and function of the glycosylation machinery.

The effect of decreasing length of stay on discharge destination and readmission after coronary bypass operation

BACKGROUND

Over the decade of the 1990s, hospital stay after operation declined in response to prospective payment and managed care. As a result, complications previously detected and treated in the hospital may have begun to occur after discharge. In addition, discharge to nursing homes and rehabilitation hospitals may have increased. To address these questions, we used a statewide database to look at the use of postacute care and the 30-day readmission and mortality after coronary bypass operation.

METHODS

A modification of the Commonwealth of Massachusetts Division of Health Care Finance and Policy discharge data to include a unique patient identifier allowed us to retrospectively track patient destination at discharge and study 30-day readmission to all hospitals in the state.

RESULTS

Over the 3-year period after the institution of the unique patient identifier (1993 to 1996), postoperative length of stay after coronary bypass operation decreased from 7.4 to 6 days (19%, P <.0005), but the 30-day readmission rate (17.7%) did not increase. Discharge to rehabilitation hospitals and skilled nursing facilities rose significantly (11.7% to 23.8%), especially in the Medicare population (17.2% to 38.5%). Mortality in the 30 days after discharge remained constant at 0.3%.

CONCLUSIONS

A shorter postoperative length of stay did not appear to disadvantage coronary artery bypass patients by increasing their likelihood of readmission or death. Cost savings from reduced length of stay were offset by increased use of postacute services.

Reproducibility of the blood lactate threshold, 4 mmol.l(-1) marker, heart rate and ratings of perceived exertion during incremental treadmill exercise in humans

The aim of this study was to investigate the reproducibility of blood lactate measurements, heart rate (HR) and ratings of perceived exertion (RPE) during treadmill exercise at speeds corresponding to the lactate threshold ( v(Th,la)-) and a fixed blood lactate concentration of 4 mmol.l(-1)( v(la)-(,4)). Possible differences in reproducibility related to fitness levels were also investigated. A group of 20 men [mean (SD)] [age 20.5 (1.4) years] and 16 women [age 21.2 (0.9) years] took part in the study. The subjects performed two identical incremental exercise tests consisting of at least six 4 min stages. Blood lactate concentrations, HR and RPE were recorded at the end of each stage. Limits of agreement (LoA), correlation coefficients and 95% confidence intervals for the mean difference between tests were employed to investigate the level of agreement and reproducibility of blood lactate concentration, HR and RPE. For the group as a whole, the sample correlation coefficient for speed at v(Th,la)- was r=0.88, and was r=0.92 for the speed at v(la)-(,4). At v(Th,la) -, the correlation coefficients for the moderately fit and unfit were r=0.94 and r=0.36, respectively, and at v(la)-(,4) r=0.93 and r=0.68, respectively. The LoA for the moderately fit group indicated that a change of 1.62 km.h(-1) in v(Th,la)- would be necessary to be considered a change in training status. For HR and RPE, relationships between the tests were generally poor. The LoA suggested that changes in scores must be unacceptably large. These findings cast doubt on the sensitivity of testing for change of blood lactate concentration, HR and RPE in this population.

A comparison of mountain rescue casualty bags in a cold, windy environment

OBJECTIVE

To help the Mountain Rescue Association of Scotland find the best protective mountain rescue casualty bag in cold and windy conditions. The study investigated how 3 different casualty bags (labeled Bag 1, Bag 2, and Bag 3) performed in a cold (-10 degrees C, dry bulb), windy (wind speed 3.0 m x s(-1)) environment using physiological and subjective responses of the participating subjects.

METHODS

Eleven male subjects, aged 23.4+/-4 years, percentage body fat 15.5+/-2 (mean +/- SD). Each participated in a total of 3 tests (1 for each bag). The tests were scheduled to last 60 minutes. Core and skin temperatures (skin values were measured on the arm, chest, thigh, and calf, and a mean skin temperature was calculated) were measured during the tests. Heart rate, oxygen consumption (Vo2), and subjective cold perception ratings were also recorded at regular intervals throughout the test duration. All variables except for Vo2 and cold discomfort were adjusted for baseline.

RESULTS

There was a significant difference in the mean response between the bags for the following variables: arm, chest, thigh, calf, mean temperature, and cold discomfort.

CONCLUSIONS

All 3 bags showed limited ability to protect the subjects in cold, windy conditions. However, the study shows that Bag 2 offered the least protection against the imposed environment. It is difficult to differentiate between the other 2 bags, because Bag 1 performed better than Bag 3 for arm, calf, and mean temperatures, while Bag 3 outperformed Bag 1 for chest and thigh temperatures and cold discomfort scores.

Lactobacillus helveticus glycosyltransferases: from genes to carbohydrate synthesis

Bioactive carbohydrates are crucial in mediating essential biological processes, and their biosynthesis is an essential aspect to develop for a global view of their biological functions. Lactic acid bacteria display an array of diverse and complex carbohydrates and, therefore, are of particular interest. Here we present the identification of a novel exocellular polysaccharide structure and the corresponding gene cluster from Lactobacillus helveticus NCC2745. The development of a glycosyltransferase-specific enzymatic assay allowed the assignment of sugar specificities, which as a general approach will for the future permit a faster and more direct characterization of glycosyltransferase specificities. A model of the biosynthesis of the repeating unit is proposed. EpsE is a phosphoglucosyltransferase initiating the repeating unit biosynthesis by linking a glucose residue to a membrane-associated lipophilic acceptor. EpsF elongates the carbohydrate chain by forming an alpha(1,3)-Glcp linkage onto the first Glcp, whereas EpsG adds a backbone alpha(1,6)-Galp onto alpha-Glcp and EpsH attaches a alpha(1,6)-Glcp branch onto the first glucose residue. Finally, EpsI would add a beta(1,6)-Galp linkage onto alpha-Glcp terminating the sidechain and EpsJ would terminate the synthesis of the polysaccharides' repeating unit by forming a beta(1,3)-Galp linkage onto alpha-Galp.

Modified composite or conventional glass ionomer for band cementation? A comparative clinical trial

The time to first failure, the position of band failure at deband, and the change in enamel white spot lesions of teeth bonded with a modified composite or a conventional glass ionomer were compared in a randomized half-mouth trial over the full course of orthodontic treatment. One hundred forty band pairs were cemented in 98 subjects. Overall band failure rates of 5% and 2.8% were recorded for the modified composite and the conventional glass ionomer, respectively, with no significant difference found between their times to first band failure. At the end-of-treatment deband, the position of band failure was predominantly at the enamel-cement interface for the modified composite and at the band-cement interface for the conventional glass ionomer (P <.001). A comparison of changes in mean enamel white spot lesion scores during treatment did not reveal significant differences between the cement groups (P =.16).

Risk factors for excess weight gain in children treated for acute lymphoblastic leukaemia

OBJECTIVE

To test whether excess weight gain in patients treated for childhood acute lymphoblastic leukaemia (ALL) was predictable using patient characteristics at diagnosis.

DESIGN AND SUBJECTS

Longitudinal study of changes in body mass index (BMI) in all 98 patients treated in Scotland on treatment protocol MRC UKALL-XI who had reached at least 3y post-diagnosis in first remission.

MEASUREMENTS

The influence of the following variables on changes in BMI, expressed as a standard deviation score (SDS), was tested using variable selection techniques and classification and regression trees: BMI SDS at diagnosis; age at diagnosis; gender; socioeconomic status; treatment.

RESULTS

Prevalence of obesity (BMI SDS>2.0) was <2% at diagnosis, but increased to 16% at 3y. Gain in BMI SDS was significantly inversely influenced by BMI SDS at diagnosis (P<0.01) and age at diagnosis (P<0.01).

CONCLUSION

Obesity is common in ALL by the end of therapy, and is more likely in children who are younger and thinner at diagnosis. Excess weight gain was not readily predictable from routinely collected information available at diagnosis and so all children treated for ALL should be considered 'at risk' of excess weight gain and the target of obesity prevention.

A comparative clinical trial of a compomer and a resin adhesive for orthodontic bonding

The study aimed to compare the survival time and cariostatic potential of a compomer to that of a resin adhesive when used to bond stainless steel orthodontic brackets to labial segment teeth only. The effect of the patients' sex, age at the start of treatment and presenting malocclusion on bracket survival time was assessed also. Forty-five consecutive patients who attended for fixed appliance therapy were randomly selected. Four hundred twenty-six brackets were bonded (213 with compomer and 213 with resin adhesive) with a split mouth design; the right or left side allocation of compomer in either arch was alternated. Color transparencies of the maxillary incisors, mandibular incisors, or both, and transparencies of the canines, were taken before treatment. At the debond stage, the transparencies were projected (20x) and assessed by an experienced examiner, who used a caries index. The survival time distributions for brackets bonded with each bonding agent were not significantly different (P = .74, paired Prentice-Wilcoxon test; P = .75, Akritas test), with bracket failure rates of 17% and 20% recorded for compomer and resin adhesive, respectively. Neither the patients' sex (P = .85) nor malocclusion (P = .26) appear to affect significantly bracket survival, but patient age was identified as a useful prognostic indicator of bracket survival (P < .001). On average, there was more decalcification related to brackets bonded with resin adhesive than with compomer (P = .0075). Survival time distributions of brackets bonded with compomer or resin adhesive appear comparable, but decalcification was reduced significantly by bonding with compomer.

The effect of amlodipine on respiratory and pulmonary vascular responses to hypoxia in mountaineers

Calcium antagonists are known to reduce the incidence of high-altitude pulmonary oedema, but the mechanism is unclear. The aim of this study was to examine the effects of the calcium antagonist, amlodipine, on cardiac and respiratory responses in normoxia and hypoxia. Fourteen normal subjects aged 31+/-4 yrs who had climbed to altitudes of 5,000-7,500 m without problems were randomly assigned to a double-blind crossover trial of amlodipine versus placebo, using sea-level inspiratory hypoxia to simulate altitude. Doppler echocardiographic estimates of resting pulmonary haemodynamics and cycle ergometer test results of cardiorespiratory responses to exercise were recorded in normoxia and hypoxia. It was found that, although hypoxic pulmonary vasoconstriction (HPV) was not significantly reduced by amlodipine, the effect of the drug on HPV was inversely related to the serum level of amlodipine. Amlodipine did not alter left ventricular function measured echocardiographically. During exercise, amlodipine increased breathlessness, measured using standard scales, in both normoxia and hypoxia but had no effect on ventilatory variables. It was concluded that amlodipine has the potential to block hypoxic pulmonary vasoconstriction as evidenced by a drug concentration-related decrease in resting tricuspid regurgitation jet velocity without any change in resting myocardial contractility. However, with amlodipine, the subjects felt more breathless during exercise. The reasons for this increase in breathlessness are not clear.

Tuberculosis in Pakistan: socio-cultural constraints and opportunities in treatment

This study explores the extent to which factors related to individuals, the care provision process, and the cultural context influence the behaviour of tuberculosis patients attending TB clinics in rural Pakistan, and examines the effects of disease on their personal lives. Thirty-six patients attending three TB treatment clinics were interviewed in depth. These patients were stratified by stage of treatment (treatment proceeding, treatment completed, default), sex and by rural/urban status. Results indicate that the majority of patients were very poor, but nonetheless initially chose to attend private practitioners. Normally their disease was correctly diagnosed as tuberculosis only after repeated visits to a succession of health care providers. Patients' knowledge about their disease was limited, and doctors gave incorrect or only very limited health education. Most patients reported dissatisfaction with care provided. Almost all patients reported problems with access to treatment, both in terms of time and money; this was particularly true of women, whose freedom to travel in Pakistan is limited. Potential causes of default appeared to be more closely linked to deficiencies in treatment provision rather than patients' unwillingness to comply. Largely because of a perception that TB was incurable, respondents were generally unwilling to disclose that they were undergoing or had undergone TB treatment. For reasons related to confidential access to treatment, this could lead to default, perpetuating the perception of incurability, and hence causing a vicious circle. For TB programmes to be successful in Pakistan, it is essential that this circle is broken; and this can only be done through provision of good quality TB care and education to improve the population's understanding that TB can be cured. In addition, patients' unwillingness to disclose to health care providers that they had already received previous treatment meant that many patients were prescribed incorrect treatment regimes, potentially leading to the emergence of drug-resistant TB. In common with other researchers' findings, no clear differences were found between those who had completed treatment and those who had defaulted from treatment. This study was performed to provide information to assist the researchers to design potential TB treatment delivery strategies, and has proved invaluable for this purpose. Strategies based on findings from the study are currently being assessed using a randomised controlled trial.

Echocardiographic determination of risk area size in a murine model of myocardial ischemia

Genetically altered mice are useful to understand cardiac physiology. Myocardial contrast echocardiography (MCE) assesses myocardial perfusion in humans. We hypothesized it could evaluate murine myocardial perfusion before and after acute coronary ligation. MCE was performed before and after this experimental myocardial infarction (MI) in anesthetized mice by intravenous injection of contrast microbubbles and transthoracic echo imaging. Time-video intensity curves were obtained for the anterior, lateral, and septal myocardial walls. After MI, MCE defects were compared with the area of no perfusion measured by Evans blue staining. In healthy animals, intramyocardial contrast was visualized in all the cardiac walls. The anterior wall had a higher baseline video intensity (53 +/- 17 arbitrary units) than the lateral (34 +/- 13) and septal (27 +/- 13) walls (P < 0.001) and a lower increase in video intensity after contrast injection [50 +/- 17 vs. 60 +/- 24 (lateral) and 65 +/- 29 (septum), P < 0.01]. After MI, left ventricular (LV) dimensions were enlarged, and the shortening fraction was decreased. A perfusion defect was imaged with MCE in every mouse, with a correlation between MCE perfusion defect size (35 +/- 13%) and the nonperfused area by Evans blue (37 +/- 16%, y = 0.77x + 6.1, r = 0.93, P < 0. 001). Transthoracic MCE is feasible in the mouse and can accurately detect coronary occlusions and quantitate nonperfused myocardium.

Correlation of CT findings with clinical evaluations in 261 patients with symptomatic bronchiectasis

OBJECTIVE

In a multicenter study, we evaluated the relationships between the extent and severity of bronchiectasis on CT and clinical symptoms, spirometric abnormality, and sputum characteristics.

SUBJECTS AND METHODS

The study population included 261 patients with symptomatic, physiologically significant bronchiectasis, who were enrolled in another study evaluating the clinical efficacy of deoxyribonudease in treatment of bronchiectasis. Patients with cystic fibrosis, allergic bronchopulmonary aspergillosis, and fungal or mycobacterial infection were excluded. In addition to high-resolution CT scanning, all patients underwent clinical evaluation, spirometry, and sputum culture. CT features scored by consensus of two observers included the extent of bronchiectasis, type of bronchiectasis (cylindric, varicose, or cystic), extent of mucoid impaction, and degree of bronchial wall thickening.

RESULTS

Scores for the severity and extent of bronchiectasis correlated with the forced expiratory volume in 1 sec (FEV1) (r = -.362, p < .0001) and with the forced vital capacity (FVC) (r = -.362, p < .0001). Scores for bronchial wall thickening correlated with the FEV1 (r = -.367, p < .0001) and FVC (r = -.239, p < .001). Patients with cystic bronchiectasis were significantly more likely to grow Pseudomonas from their sputa and to have purulent sputa than were patients with cylindric or varicose bronchiectasis. Patients with cystic bronchiectasis had significantly lower FEV1 and FVC values than did patients with cylindric or varicose bronchiectasis.

CONCLUSION

In this patient population, we found weak but significant correlations between the degree of morphologic abnormality on CT and the extent of physiologic impairment. Cystic bronchiectasis was associated with sputum purulence and with the growth of Pseudomonas. CT classification of the type of bronchiectasis may be useful as an index of severity of disease.

Genetic and environmental influences in the development of multiple primary melanoma

OBJECTIVES

To identify risk factors and the prognosis associated with the development of multiple primary melanoma (MPM).

DESIGN

Case-comparison studies of subjects with MPM and single primary melanoma. Sequencing of CDKN2A in germline DNA.

SETTING

Population-based study of patients with invasive melanoma in Scotland between 1979 and 1996.

PATIENTS

For mortality studies, 108 patients with MPM and 216 single melanoma controls matched for age, sex, site, and tumor thickness. For risk factor studies, 48 patients with MPM and 48 single melanoma controls matched as above. For CDKN2A analysis, a sample of 23 subjects with MPM.

RESULTS

The development of MPM was found not to be an independent prognostic factor. The risk of MPM was greatest in those with a family history of melanoma, with large numbers of benign nevi, and the presence of clinically or histologically atypical nevi. Germline mutations of CDKN2A were present in 6 of 23 patients with MPM and in 5 cases consisted of the base pair substitution Met53Ile.

CONCLUSIONS

The importance of MPM should be addressed in melanoma follow-up protocols. Those patients at greatest risk can be identified by a family history of melanoma and their mole pattern. Germline mutations in CDKN2A occur in both familial and sporadic MPM and further studies are required to determine the value of analysis of this gene in melanoma surveillance. Patients should be informed that the development of MPM does not adversely affect their prognosis.

Incidence and occupational pattern of leukaemias, lymphomas, and testicular tumours in western Ireland over an 11 year period

STUDY OBJECTIVE

To determine incidence of the following malignancies, testicular tumours, all leukaemias and all lymphomas in the West of Ireland in an 11 year period. Secondly, to examine the relation between disease patterns and available occupational data in male subjects of working age.

DESIGN

A census survey of all cases occurring in the three counties in the Western Health Board (WHB) area, Galway, Mayo and Roscommon, for the 11 year period 1980 to 1990 inclusive. Average annual age standardised incidence rates for the period were calculated using the 1986 census data. Rates for the area are compared with rates from the southern region of Ireland, which had a tumour registry. Trends over the time period are evaluated. All male subjects for whom occupational data were available were categorised using the Irish socioeconomic group classification and incidence rates by occupation were compared using the standardised incidence ratio method. In one of the counties, Galway, a detailed occupational history of selected cases and an age matched control group was also elicited through patients' general practitioners.

SETTING

All available case records in the West of Ireland.

RESULTS

There are no national incidence records for the period. Compared with data from the Southern Tumour Registry, the number of cases of women with myeloid leukaemias was significantly lower. Male leukaemia rates were significantly lower as a group (SIR 84 (95% CI 74, 95) but not when considered as individual categories. Regression analysis revealed an increasing trend in the number of new cases of non-Hodgkin's lymphoma among both men (r = 0.47, p = 0.02) and women (r = 0.90, p = 0.0001) and of chronic lymphocytic leukaemia in men (r = 0.77, p = 0.005) and women (r = 0.68 p = 0.02) in the WHB region over the last decade. Four hundred and fifty six male cases over the age of 15 years were identified and adequate occupational information was available for 74% of these. Standardised incidence ratios of testicular tumours 100, 938) and agriworkers other than farmers (SIR 377, 95% CI 103, 967). There were also significantly increased incidence ratios for both non-Hodgkin's lymphoma (SIR 169, 95% CI 124, 266) and three categories of leukaemias among farmers. Hodgkin's disease and acute myeloid leukaemias were significantly increased among semi-skilled people. Interview data with 90 cases and 54 controls of both sexes revealed that among farmers, cases (n = 31) were significantly less likely than controls (n = 20) to use tractor mounted spraying techniques (OR = 0.19 (95% CI 0.04, 0.80)) and less likely to wear protective masks (OR 0.22 (95% CI 0.05, 0.84)).

CONCLUSIONS

Trends of increase in non-Hodgkin's lymphoma and some leukaemias are consistent with studies elsewhere. The study provides further evidence of the relation between agricultural work and certain lymphoproliferative cancers. The possible carcinogenic role of chemicals used in agricultural industries must be considered as an explanation.

A novel role for Rab5-GDI in ligand sequestration into clathrin-coated pits

BACKGROUND

Clathrin-coated pits are formed at the plasma membrane by the assembly of the coat components, namely clathrin and adaptors from the cytosol. Little is known about the regulation and mechanism of this assembly process.

RESULTS

We have used an in vitro assay for clathrin-coated pit assembly to identify a novel component required for the invagination of newly formed coated pits. We have purified this cytosolic component and shown it to be a complex of Rab5 and GDI (guanine-nucleotide dissociation inhibitor), that was previously demonstrated to be involved in downstream processing of endocytic vesicles. Using a combination of quantitative electron microscopy and in vitro endocytosis assays, we have demonstrated that although coat proteins and ATP are sufficient to increase the number of new coated pits at the cell surface in permeabilised cells, the Rab5-GDI complex is required for ligand sequestration into clathrin-coated pits.

CONCLUSIONS

We have identified Rab5 as a critical cytosolic component required for clathrin-coated pit function. Given the well-established role of Rab5 in the fusion of endocytic vesicles with endosomes, our results suggest that recruitment of essential components of the targeting and fusion machinery is coupled to the formation of functional transport vesicles.

Comparative effects of cyclosporin on glycosaminoglycan synthesis by gingival fibroblasts

Histological studies show that drug-induced gingival overgrowth results from an accumulation of the connective tissue component. Despite comprising a major part of gingival connective tissue, a role for glycosaminoglycans (GAGs) in the pathogenesis of gingival overgrowth has received scant attention. By analyzing the metabolism of 3H-glucosamine, we have compared GAG and hyaluronan synthesis by fibroblasts derived from normal and overgrown gingival tissue, and the effects of cyclosporin on GAG output. GAG production was cell density-dependent, fibroblasts cultured at low density synthesizing significantly increased quantities in comparison to confluent cultures. The effects of cyclosporin on GAG synthesis was also found to be both cell density- and cell strain-dependent. However, cyclosporin-stimulated GAG synthesis by 2/3 overgrown cell strains and 1/3 normal strains. These results suggest that a direct promotion of GAG synthesis by gingival fibroblasts in response to cyclosporin may play a role in the pathogenesis of gingival overgrowth.

Patterns of sexual behaviour in a rural population in north-western Tanzania

The HIV epidemic in sub-Saharan Africa has been characterised by the predominance of heterosexual transmission. Patterns of sexual behaviour have been implicated in the spread of the epidemic, but few quantitative data are available on sexual behaviour in rural populations in Africa. This paper reports data from a survey of 1117 adults aged 15-54 years selected randomly from twelve rural communities in Mwanza Region, Tanzania. Sexual debut occurred early, 50% of women and 46% of men reporting first sex before age 16. On average, women married 1.8 years and men 6.1 years after their sexual debut. In women, age at sexual debut appears to have increased over time, in parallel with an increase in age at first marriage. Men were generally married later, to women around five to ten years younger than themselves. Marital dissolution and remarriage were common in both sexes. Reported numbers of sexual partners were compared with those recorded in a population survey in Britain. More men reported 10 or more lifetime partners, or three or more partners in the past year, in rural Mwanza (48% and 29%) than in Britain (24% and 6%). Women reported fewer partners, and results were broadly similar to British data. Casual sex during the past year was reported by 53% of the men and 15% of the women, but only 2% of men reported sexual contact with bar girls or commercial sex workers. Only 20% of men and 3% of women had ever used a condom. Interventions are needed to reduce the high levels of sexual partner change and casual sex, and low levels of condom use, recorded in this rural population. Targeting of interventions to traditional "core groups" may be of limited value in rural areas, and additional strategies are needed, focusing particularly on teenagers who are at high risk of HIV and other sexually transmitted diseases.

A study of the impact of Sun Awareness Week 1995

We report a questionnaire-based survey of parents of schoolchildren to assess the impact of Sun Awareness Week, organized by the U.K. Skin Cancer Working Party, from 4 to 10 June 1995. A questionnaire was designed, pre-tested and modified. Nine hundred and eighty-nine patients of schoolchildren were approached before and after Sun Awareness Week at eight comprehensive primary schools and a children's clothes shop. Responses to the questionnaires were analysed in the following categories: total knowledge, sunscreen knowledge, melanoma risk factor knowledge, attitude, self-reported behaviour and awareness of the link between childhood sun exposure and cancer (link). A reasonable level of knowledge was demonstrated in the sample population. Significant improvements in attitude and behaviour scores were observed (P < 0.05). Three of the four link questions were significantly improved (P < 0.005). These results were not explained by differences in age, sex, or occupation between the before and after populations. Further national studies are needed to establish long-term benefits of such interventions.

Sexual behaviour and sex education in Irish school-going teenagers

The sexual behaviour and factors which affect such behaviour, source of knowledge and education about sex was assessed by means of an anonymous self-administered questionnaire among 2754 pupils (15-18 years) attending 40 (85%) second level schools in Galway City and County. The purpose of the study was to make recommendations in relation to a school sexual health education programme. Overall 21% of pupils had had sexual intercourse, with boys more than twice as likely as girls to have experienced this. The mean age of first sexual intercourse was 15.5 years, 72% reported having used a condom at first intercourse but of 475 pupils who had sexual intercourse regularly only 67% used condoms all the time with 33% using them sometimes or never. Over half reported that first intercourse was with a 'casual' partner and 35% and 9% respectively claimed that alcohol and non-prescribed drugs were a contributory factor. In relation to sexual risk beliefs, 72% believed that condoms used properly reduced the risk of sexually transmitted diseases (STDs) and 78% knew that the contraceptive pill is not protective against human immunodeficiency virus (HIV) infections. While the level of knowledge regarding sex education was generally high over one-third of sexually active respondents had been involved in high-risk behaviour. A need for health education programmes which focus on behaviour change and assertiveness has been identified.

Sexual behaviour patterns and other risk factors for HIV infection in rural Tanzania: a case-control study

OBJECTIVE

To examine the association between HIV infection and patterns of sexual behaviour and other risk factors in a rural Tanzanian population in a case-control study, nested within a randomized trial of improved sexually transmitted disease treatment.

METHODS

All HIV-positive patients from the baseline survey of the randomized trial were eligible as cases. Cases (n = 338) and controls (a random sample of one in eight HIV-negative persons; n = 1078) were interviewed about risk factors for HIV infection using a structured questionnaire.

RESULTS

A significantly higher HIV prevalence was found among men and women not currently employed in farming [men: odds ratio (OR), 2.08; women: OR, 3.65], women who had travelled (OR, 3.27), educated women (OR, 4.51), and widowed/ divorced people compared with those currently married (men: OR, 3.10; women: OR, 3.54). Two spouse-related factors were significantly associated with HIV, even after adjustment for the sexual behaviour of the index case: HIV was more prevalent in men with younger spouses (P = 0.020 for trend) and in women married to men currently employed in manual work, office work or business (OR, 2.20). In women only, blood transfusions were associated with a higher HIV prevalence (OR, 2.40), but only a small population attributable fraction (4%). There was an increased HIV prevalence associated with increasing numbers of injections. Reported number of lifetime sexual partners was significantly associated with HIV infection (women: OR, 7.33 if > or = 10 lifetime partners compared with < or = 1; men: OR, 4.35 for > or = 50 compared with < or = 1). After adjustment for confounders, male circumcision was associated with a lower HIV prevalence (OR, 0.65; P = 0.11).

CONCLUSIONS

In these rural communities, many HIV infections occur through sexual transmission. Some people are at high risk of HIV infection through large numbers of sex partners, whereas some are at risk through their spouse or regular partner. The role of circumcision in HIV transmission is unclear. Commercial sex seems to play a negligible role in HIV transmission in these communities. Our results confirm marked heterogeneity in HIV risk, indicating the scope for risk reduction strategies.

Multiple sclerosis with hydromyelia demonstrated at autopsy

Multiple sclerosis (MS) associated with intramedullary cysts has been recently documented radiographically in approximately a dozen cases, but histological confirmation in these cases has been lacking. These cysts have been noted to occur centrally in the spinal cord and have been previously diagnosed as syringomyelia. We report a patient with extensive hydromyelia, but no dissecting syringomyelic cavity, of the thoraco-lumbar spinal cord, which was co-existent with centrally located, non-necrotic, chronic demyelinative plaques. A few well demarcated non-necrotic plaques were seen in the cerebrum and cerebellum with sparing of optic chiasm, confirming the diagnosis of chronic, non-Devic type MS. Although a cause and effect between the hydromyelia and MS cannot be proven in this or any of the previously reported radiographic cases our report provides pathological confirmation of the association between these two entities and further delineates the type of cyst.

Asymptomatic gonorrhoea and chlamydial infection in rural Tanzanian men

OBJECTIVE

To measure the prevalence of urethritis due to Neisseria gonorrhoeae and Chlamydial infection trachomatis in rural Tanzanian men

DESIGN

About 500 men aged 15-54 years were selected from each of 12 rural communities by random cluster sampling; interviewed concerning past or present symptoms of sexually transmitted diseases; and asked to provide a first catch urine specimen, which was tested for pyuria with a leucocyte esterase dipstick test. Subjects with symptoms or with a positive result on testing were examined, and urethral swabs were taken for detection of N gonorrhoeae by gram stain and of C trachomatis by antigen detection immunoassay.

SETTING

Mwanza region, north western Tanzania.

SUBJECTS

5876 men aged 15-54 years.

MAIN OUTCOME MEASURES

Prevalence of urethral symptoms, observed urethral discharge, pyuria, urethritis ( > 4 pus cells per high power field on urethral smear), N gonorrhoeae infection (intracellular gram negative diplococci), and C trachomatis infection (IDEIA antigen detection assay).

RESULTS

1618 (28%) subjects reported ever having a urethral discharge. Current discharge was reported by 149 (2.5%) and observed on examination in 207 (3.5%). Gonorrhoea was found in 128 subjects (2.2%) and chlamydial infection in 39 (0.7%). Only 24 of 158 infected subjects complained of urethral discharge at the time of interview (15%).

CONCLUSION

Infection with N gonorrhoeae and C trachomatis is commonly asymptomatic among men in this rural African population. This has important implications for the design of control programmes for sexually transmitted disease.

A community trial of the impact of improved sexually transmitted disease treatment on the HIV epidemic in rural Tanzania: 1. Design

OBJECTIVE

To describe the rationale and design of a randomized trial of the impact of improved services for the treatment of sexually transmitted diseases (STD) on the incidence of HIV infection in Mwanza Region, Tanzania.

METHODS

The likely impact of improved STD treatment services on HIV incidence, and the need for empirical information on the effectiveness of this intervention strategy, are discussed. The rationale and design of such an intervention programme in Mwanza Region, and of a community-randomized trial to measure the impact of the programme on HIV and other STD, are presented. Problems in the design and interpretation of the trial are reviewed.

RESULTS

Results of the baseline survey of the cohort of over 12,000 adults in 12 communities are presented in a companion paper.

CONCLUSION

There is an urgent need for effective preventive measures against the HIV epidemic in sub-Saharan Africa and other developing regions. Improved STD treatment has been promoted as a potentially effective strategy, but there is little empirical information on its impact. The trial in Mwanza Region is the first randomized study of this intervention and should provide valuable data for health policy makers.

A community trial of the impact of improved sexually transmitted disease treatment on the HIV epidemic in rural Tanzania: 2. Baseline survey results

OBJECTIVES

To determine baseline HIV prevalence in a trial of improved sexually transmitted disease (STD) treatment, and to investigate risk factors for HIV. To assess comparability of intervention and comparison communities with respect to HIV/STD prevalence and risk factors. To assess adequacy of sample size.

SETTING

Twelve communities in Mwanza Region, Tanzania: one matched pair of roadside communities, four pairs of rural communities, and one pair of island communities. One community from each pair was randomly allocated to receive the STD intervention following the baseline survey.

METHODS

Approximately 1000 adults aged 15-54 years were randomly sampled from each community. Subjects were interviewed, and HIV and syphilis serology performed. Men with a positive leucocyte esterase dipstick test on urine, or reporting a current STD, were tested for urethral infections.

RESULTS

A total of 12,534 adults were enrolled. Baseline HIV prevalences were 7.7% (roadside), 3.8% (rural) and 1.8% (islands). Associations were observed with marital status, injections, education, travel, history of STD and syphilis serology. Prevalence was higher in circumcised men, but not significantly after adjusting for confounders. Intervention and comparison communities were similar in the prevalence of HIV (3.8 versus 4.4%), active syphilis (8.7 versus 8.2%), and most recorded risk factors. Within-pair variability in HIV prevalence was close to the value assumed for sample size calculations.

CONCLUSIONS

The trial cohort was successfully established. Comparability of intervention and comparison communities at baseline was confirmed for most factors. Matching appears to have achieved a trial of adequate sample size. The apparent lack of a protective effect of male circumcision contrasts with other studies in Africa.