Sample size calculations for the design of cluster randomized trials: A summary of methodology.

Cluster randomized trial designs are growing in popularity in, for example, cardiovascular medicine research and other clinical areas and parallel statistical developments concerned with the design and analysis of these trials have been stimulated. Nevertheless, reviews suggest that design issues associated with cluster randomized trials are often poorly appreciated and there remain inadequacies in, for example, describing how the trial size is determined and the associated results are presented. In this paper, our aim is to provide pragmatic guidance for researchers on the methods of calculating sample sizes.

Alternative splicing generates a novel truncated Cav1.2 channel in neonatal rat heart.

L-type Cav1.2 Ca(2+) channel undergoes extensive alternative splicing, generating functionally different channels. Alternatively spliced Cav1.

Hemodynamic analysis of patient-specific coronary artery tree.

Local hemodynamic parameters, such as wall shear stress (WSS), oscillatory shear index and relative resident time (RRT), have been linked to coronary plaque initiation and progression. In this study, a left coronary artery tree model was reconstructed from computed tomography angiography images of a patient with multiple stenoses. The geometry of the coronary artery tree model was virtually restored by eliminating the lesions, essentially re-creating the virtually healthy artery anatomy.

Risks and benefits of weight loss in heart failure.

Obesity adversely affects many cardiovascular disease (CVD) risk factors and increases the risk of most CVD, including heart failure (HF). HF is markedly increased in the setting of obesity. However, obese patients with HF have a better prognosis than lean patients with HF, which has been termed the obesity paradox.

Assessment of left ventricular preload by cardiac magnetic resonance imaging predicts exercise capacity in adult operated tetralogy of Fallot: a retrospective study.

Background: The optimal timing of pulmonary homograft valve replacement (PVR) is uncertain. Cardiopulmonary exercise testing (CPET) and cardiac magnetic resonance (CMR) are often used to guide the clinical decision for PVR in operated tetralogy of Fallot (TOF) patients with significant pulmonary regurgitation (PR). We aim to study the relationship between exercise capacity and CMR in these patients.

Cardiovascular implications of obstructive sleep apnea associated with the presence of a patent foramen ovale.

Patent foramen ovale (PFO) is a common congenital cardiac abnormality of the atrial septum which occurs in 25% of the population. It allows communication between the right and left atrium enabling right to left shunting of deoxygenated blood (after birth) which may be linked to strokes or transient ischemic attacks. PFO may also have an association with obstructive sleep apnea (OSA).

Heart failure and obesity in adults: pathophysiology, clinical manifestations and management.

Obesity is both a risk factor and a direct cause of heart failure (HF) in adults. Severe obesity produces hemodynamic alterations that predispose to changes in left ventricular morphology and function, which, over time, may lend to the development of HF (obesity cardiomyopathy). Certain neurohormonal and metabolic abnormalities as well as cardiovascular co-morbidities may facilitate this process.

Obesity paradox, cachexia, frailty, and heart failure.

Overweight and obesity adversely affect cardiovascular (CV) risk factors and CV structure and function, and lead to a marked increase in the risk of developing heart failure (HF). Despite this, an obesity paradox exists, wherein those who are overweight and obese with HF have a better prognosis than their leaner counterparts, and the underweight, frail, and cachectic have a particularly poor prognosis. In light of this, the potential benefits of exercise training and efforts to improve cardiorespiratory fitness, as well as the potential for weight reduction, especially in severely obese patients with HF, are discussed.

Is there a role for the incretin system in blood pressure regulation?

Incretin-based therapies are now well established for diabetes management and are among the frontline agents for control of hyperglycemia. In addition to their antihyperglycemic effects, evidence is emerging on the role of these agents on blood pressure regulation, cardioprotective and renoprotective properties. Because of the pleiotropic nature of these affects, these agents could offer significant benefits with regards to the cardiorenal metabolic complications that are part of the diabetes and obesity epidemic in the United States and worldwide.

Psychogenic non-epileptic seizures: a challenging entity.

Psychogenic non-epileptic seizures (PNES) are commonly encountered in neurologic practice. They are often misdiagnosed as epileptic seizures and treated as such for several years before a correct diagnosis is established. Such a misdiagnosis has the potential to expose patients to undue risk through several anti-epileptic drugs (AEDs).

Toward a human-centered hyperlipidemia management system: the interaction between internal and external information on relational data search.

In a distributed information search task, data representation and cognitive distribution jointly affect user search performance in terms of response time and accuracy. Guided by UFuRT (User, Function, Representation, Task), a human-centered framework, we proposed a search model and task taxonomy. The model defines its application in the context of healthcare setting.

Reversible sensorineural hearing loss with normal brainstem auditory evoked potentials in pontine hemorrhage due to capillary telangiectasia.

Capillary telangiectasias are vascular malformations most commonly found in the pons that are rarely associated with hemorrhage. We describe a unique case of pontine capillary telangiectasia causing central brainstem hemorrhage leading to reversible sensorineural deafness associated with a normal brainstem auditory evoked response.

Mitochondrial dysfunction precedes insulin resistance and hepatic steatosis and contributes to the natural history of non-alcoholic fatty liver disease in an obese rodent model.

Background & Aims: In this study, we sought to determine the temporal relationship between hepatic mitochondrial dysfunction, hepatic steatosis and insulin resistance, and to examine their potential role in the natural progression of non-alcoholic fatty liver disease (NAFLD) utilising a sedentary, hyperphagic, obese, Otsuka Long-Evans Tokushima Fatty (OLETF) rat model.

Methods: OLETF rats and their non-hyperphagic control Long-Evans Tokushima Otsuka (LETO) rats were sacrificed at 5, 8, 13, 20, and 40 weeks of age (n=6-8 per group).

Results: At 5 weeks of age, serum insulin and glucose and hepatic triglyceride (TG) concentrations did not differ between animal groups; however, OLETF animals displayed significant (p<0.

Report of anti-CCP antibody positive paraneoplastic polyarthritis and review of the literature.

A 45-year-old female presented to the rheumatology clinic with complaint of pain and swelling of multiple small joints of the hands and feet. She also complained of cough and shortness of breath onset around the same time. Since her cyclic citrullinated peptide antibody (anti-CCP) and rheumatoid factor tests were positive, rheumatoid arthritis (RA) was diagnosed and she was started on prednisone with plans for additional disease modifying therapy.

Clinical drug evaluation: the regulatory perspectives.

Introduction: This paper presents the regulatory perspectives of the clinical drug evaluation process and the role of the newly established Centre for Drug Evaluation in Singapore in this process. It describes the major drug evaluation systems in the developed countries and their similarities and differences.

Methods: The issues related to the benefits and risks assessments of new drugs are discussed, with examples, against the backdrop of the various drug evaluation systems and medical practices.