Reperfused myocardial infarction in mice: 3D mapping of late gadolinium enhancement and strain.

We developed mathematical modeling tools for mapping 3D infarct geometry from multislice late gadolinium enhancement data, allowing fusion with multislice MR tagging data, in mice with myocardial infarction. Five C57BL/6 mice were imaged at baseline, 1, 7 and 28 days after 60 min occlusion of the left anterior descending coronary artery. The 3D infarct geometry was mapped in material coordinates, and registered with 3D strain, showing permanent dysfunction in infarcted segments, intermediate function in the adjacent zone, and maintained function in the remote zone. 3D mapping of late enhancement and strain allows registration of multiple studies in a consistent framework.     

Instrumental variable approach to estimating the scalar-on-function regression model with measurement error with application to energy expenditure assessment in childhood obesity

Wearable device technology allows continuous monitoring of biological markers and thereby enables study of time-dependent relationships. For example, in this paper, we are interested in the impact of daily energy expenditure over a period of time on subsequent progression toward obesity among children. Data from these devices appear as either sparsely or densely observed functional data and methods of functional regression are often used for their statistical analyses. We study the scalar-on-function regression model with imprecisely measured values of the predictor function. In this setting, we have a scalar-valued response and a function-valued covariate that are both collected at a single time period. We propose a generalized method of moments-based approach for estimation, while an instrumental variable belonging in the same time space as the imprecisely measured covariate is used for model identification. Additionally, no distributional assumptions regarding the measurement errors are assumed, while complex covariance structures are allowed for the measurement errors in the implementation of our proposed methods. We demonstrate that our proposed estimator is L₂ consistent and enjoys the optimal rate of convergence for univariate nonparametric functions. In a simulation study, we illustrate that ignoring measurement error leads to biased estimations of the functional coefficient. The simulation studies also confirm our ability to consistently estimate the function-valued coefficient when compared to approaches that ignore potential measurement errors. Our proposed methods are applied to our motivating example to assess the impact of baseline levels of energy expenditure on body mass index among elementary school–aged children.     

The prevalence of hepatitis C virus (HCV) infection in HIV‐positive individuals in the UK – trends in HCV testing and the impact of HCV on HIV treatment outcomes

Summary. We examined the prevalence of hepatitis C virus (HCV) infection among HIV‐positive individuals in the UK, trends in HCV testing and the impact of HCV on HIV treatment outcomes. Trends over time in HCV prevalence were calculated using each patient’s most recent HCV status at the end of each calendar year. Logistic regression was used to identify factors associated with having a HCV antibody test, and Cox regression was used to determine whether HCV status was associated with the time to experiencing an immunological response to highly active antiretroviral treatment (HAART), time to virological response and viral rebound. Of the 31 765 HIV‐positive individuals seen for care between January 1996 and September 2007, 20 365 (64.1%) individuals were tested for HCV, and 1807 (8.9%) had detectable HCV antibody. The proportion of patients in follow‐up ever tested for HCV increased over time, from 782/8505 (9.2%) in 1996 to 14 280/17 872 (79.9%) in 2007. Nine thousand six hundred and sixty‐nine individuals started HAART for the first time in or after January 2000, of whom, 396 (4.1%) were HCV positive. Presence of HCV infection did not affect initial virological response, virological rebound or immunological response. The cumulative prevalence of HCV in the UK CHIC Study is 8.9%. Despite UK guidelines, over 20% of HIV‐positive individuals have not had their HCV status determined by 2007. HCV infection had no impact on HIV virological outcomes or immunological response to HIV treatment. The long‐term impact on morbidity and mortality remain to be determined.     

Treatment-seeking behaviour, cost burdens and coping strategies among rural and urban households in Coastal Kenya: an equity analysis

Ill-health can inflict costs on households directly through spending on treatment and indirectly through impacting on labour productivity. The financial burden can be high and, for poor households, contributes significantly to declining welfare. We investigated socio-economic inequities in self-reported illnesses, treatment-seeking behaviour, cost burdens and coping strategies in a rural and urban setting along the Kenyan coast. We conducted a survey of 294 rural and 576 urban households, 9 FGDs and 9 in-depth interviews in each setting. Key findings were significantly higher levels of reported chronic and acute conditions in the rural setting, differences in treatment-seeking patterns by socio-economic status (SES) and by setting, and regressive cost burdens in both areas. These data suggest the need for greater governmental and non-governmental efforts towards protecting the poor from catastrophic illness cost burdens. Promising health sector options are elimination of user fees, at least in targeted hardship areas, developing more flexible charging systems, and improving quality of care in all facilities. The data also strongly support the need for a multi-sectoral approach to protecting households. Potential interventions beyond the health sector include supporting the social networks that are key to household livelihood strategies and promoting micro-finance schemes that enable small amounts of credit to be accessed with minimal interest rates.     

Translating efficacious behavioral principles for diabetes prevention into practice

This case study describes the process of translating efficacy-based Diabetes Prevention Program principles into a practical format for delivery within a managed care organization. Using Rogers' innovation-decision process model, the authors tracked the adoption, implementation, and short-term effectiveness of a clinical program. Effectiveness was documented using a pre-post design to detect changes in physical activity and dietary habits. Participants (N = 298) were Kaiser Permanente of Colorado patients enrolled in diabetes-prevention classes. Changes were analyzed using paired-samples t tests and one-way analysis of variance. Participants significantly increased reported minutes of moderate (p < .001, mu = 84.52, CI: 58.44-110.61) and vigorous (t = 2.220, p = .028, mu = 19.05, CI: 2.10-36.00) physical activity and their daily servings of fruits and vegetables (p < .001, mu = 0.20, CI: 0.13-0.27). By identifying the underlying strategies that led to efficacy, professionals can implement sound diabetes-prevention programs that fit within their context.     

Convulsant effect of diphenyl diselenide in rats and mice and its relationship to plasma levels

Diphenyl diselenide [(PhSe)₂], an organoselenium compound, presents pharmacological and toxicological properties in rodents. The aim of this study was to carry out the determination and quantification of (PhSe)₂ in plasma after oral administration (p.o.) of this compound (500 mg/kg), dissolved in canola oil, in rats and mice. The second objective was to verify the involvement of different routes of administration ((p.o.), intraperitoneal (i.p.) and subcutaneous (s.c.)) and vehicle solutions (canola oil and dimethyl sulfoxide (DMSO)) in the appearance of seizure episodes and in the plasmatic levels of (PhSe)₂ in rats and mice. Analysis of (PhSe)₂ in blood samples was performed by gas chromatography/flame ionized detector system (GC/FID). Rat and mouse peak plasma (PhSe)₂ levels were 13.13 and 10.11 μg/ml (C_max), respectively, and occurred at 0.5 h (T_max) post-dosing. The use of different administration routes (p.o., i.p. and s.c.) and vehicle solutions (canola oil or DMSO) in rats and mice indicated that the appearance of seizures and (PhSe)₂ plasmatic levels are dependent of administration routes (i.p. > p.o. > s.c.), vehicle solutions (DMSO > canola oil) and animal species (mice > rat).     

Improving state pain policies: recent progress and continuing opportunities

The National Institutes of Health reports that 100 million Americans suffer from chronic pain, including pain associated with the disease of cancer. Painful conditions can strike anyone, including cancer patients and cancer survivors. Unrelieved severe pain can limit a person's functioning and sometimes even destroy the will to live. When the quality of pain relief provided is inadequate, it is usually the result of failures to apply existing knowledge about pain and its treatment, including the appropriate use of opioids. But pain relief also can be affected by the regulatory environment and fear of being investigated for excessive prescribing. The importance of evaluating and improving policies governing pain management has been recognized by national and international authorities, including the Institute of Medicine and the World Health Organization. A pilot examination of state laws and regulatory policies demonstrated that they contained a number of outdated medical concepts and prescribing restrictions and did not contain key elements of law that can make pain management a priority for licensed medical practitioners. The Pain & Policy Studies Group developed a research program to evaluate US federal and state policy governing the medical use of pain medication. This article describes 3 national policy evaluations and how the results are being used to document improvements in state pain policies. An emerging role for clinicians and their professional organizations to improve their state's pain policies is discussed.     

Bone marrow cell transplantation to the myocardium of a patient with heart failure due to Chagas' disease

We report the first case of bone marrow cell transplantation to the myocardium of a patient with heart failure due to chagas' disease. The patient is a 52-year-old man with chronic heart failure, NYHA functional class III, despite the optimized clinical therapy. The procedure consisted of aspiration of 50 mL of bone marrow through puncture of the iliac crest, followed by filtration, separation of the mononuclear cells, resuspension, and intracoronary injection. The left ventricular ejection fraction at rest, measured using radionuclide ventriculography with labeled red blood cells prior to transplantation, was 24%, and, after 30 days, it increased to 32% with no change in the medicamentous schedule. The following measurements were assessed before and 30 days after transplantation: left ventricular end diastolic diameter (82 mm and 76 mm, respectively); Minnesota living with heart failure questionaire score (55 and 06, respectively); and distance walked in the 6-minute walking test (513 m and 683 m, respectively). Our findings show that intracoronary injection of bone marrow cells may be performed, suggesting that this is a potentially safe and effective procedure in patients with due to Chagas' disease heart failure.     

Health financing to promote access in low income settings-how much do we know?

In this article we outline research since 1995 on the impact of various financing strategies on access to health services or health outcomes in low income countries. The limited evidence available suggests, in general, that user fees deterred utilisation. Prepayment or insurance schemes offered potential for improving access, but are very limited in scope. Conditional cash payments showed promise for improving uptake of interventions, but could also create a perverse incentive. The largely African origin of the reports of user fees, and the evidence from Latin America on conditional cash transfers, demonstrate the importance of the context in which studies are done. There is a need for improved quality of research in this area. Larger scale, upfront funding for evaluation of health financing initiatives is necessary to ensure an evidence base that corresponds to the importance of this issue for achieving development goals.