CADASIL presenting as schizophreniform organic psychosis.

Objective: To describe an Asian patient with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) presenting with schizophreniform organic psychosis.

Methods: Case report.

Results: We report a case of CADASIL in an Asian female presenting with frank psychotic symptoms.

Anticoagulation needs in asians with atrial fibrillation: a mythbuster.

Atrial fibrillation (AF) has long been known to increase the risk of stroke. As a result, relevant international guidelines recommend that measures to reduce the risk of thrombus formation should be considered in all patients presenting with AF. Based on risk assessment scores, patients would then receive either thrombocyte aggregation inhibitors or oral anticoagulants.

Impact of genetic polymorphisms of the renin-angiotensin system and of non-genetic factors on kidney transplant function--a single-center experience.

Renin-angiotensin-aldosterone system (RAAS) polymorphisms such as the angiotensinogen-gene-M235T-, the angiotensin-conversion enzyme (ACE)-gene I/D- and the angiotensin-II-type 1-receptor-(AT1R)-A1166C-polymorphism have been implicated in renal insufficiency and hypertension. We studied the association of these RAAS genotypes and non-genetic factors with transplant function and hypertension after renal graft transplantation (NTX). A total of 229 renal graft recipients, transplanted at a single center, were monitored up to 54 months and genotyped using polymerase chain reaction.

Key issues in conducting a meta-analysis of gene expression microarray datasets.

Adaikalavan Ramasamy and colleagues outline seven key issues and suggest a stepwise approach in conducting a meta-analysis of microarray datasets.

DNA polymorphisms and renal disease: a critical appraisal of studies presented at the annual ERA/EDTA and ASN conferences in 2004 and 2005.

Countless studies try to associate single DNA polymorphisms with disease, while there is growing evidence that many of these studies are of flawed design. Based on the Journal of the American Society of Nephrology (JASN) requirements for gene-disease association study quality, the abstracts presented at the two major international nephrology conferences in 2004 and 2005 organized by the European Renal Association/European Dialysis and Transplantation Association (ERA/EDTA) and American Society of Nephrology (ASN) are analysed to show how this problem affects nephrology. Over time, average sample numbers have increased, as have the numbers of abstracts compliant with the JASN requirements.

The "impact factor" revisited.

The number of scientific journals has become so large that individuals, institutions and institutional libraries cannot completely store their physical content. In order to prioritize the choice of quality information sources, librarians and scientists are in need of reliable decision aids. The "impact factor" (IF) is the most commonly used assessment aid for deciding which journals should receive a scholarly submission or attention from research readership.

Bone and the kidney: a systems biology approach to the molecular mechanisms of renal osteodystrophy.

Despite its apparent static condition, the skeleton undergoes a permanent process of remodeling mediated by osteoblasts and osteoclasts. The activity of these cells is regulated by a plethora of factors, ranging from mechanical stress to the effects of hormones to the immune system. One well-studied regulatory system involves the maintenance of calcium homeostasis through a network whose main regulatory components include ionized calcium, phosphate, parathyroid hormone and active vitamin D.

Relevance similarity: an alternative means to monitor information retrieval systems.

Background: Relevance assessment is a major problem in the evaluation of information retrieval systems. The work presented here introduces a new parameter, "Relevance Similarity", for the measurement of the variation of relevance assessment. In a situation where individual assessment can be compared with a gold standard, this parameter is used to study the effect of such variation on the performance of a medical information retrieval system.

An entropy-based gene selection method for cancer classification using microarray data.

Background: Accurate diagnosis of cancer subtypes remains a challenging problem. Building classifiers based on gene expression data is a promising approach; yet the selection of non-redundant but relevant genes is difficult. The selected gene set should be small enough to allow diagnosis even in regular clinical laboratories and ideally identify genes involved in cancer-specific regulatory pathways.

Volume-based non-continuum modeling of bone functional adaptation.

Background: Bone adapts to mechanical strain by rearranging the trabecular geometry and bone density. The common finite element methods used to simulate this adaptation have inconsistencies regarding material properties at each node and are computationally demanding. Here, a volume-based, non-continuum formulation is proposed as an alternative.

Antiglucocorticoid RU38486 reduces net protein catabolism in experimental acute renal failure.

Background: In acute renal failure, a pronounced net protein catabolism occurs that has long been associated with corticoid action. By competitively blocking the glucocorticoid receptor with the potent antiglucocorticoid RU 38486, the present study addressed the question to what extent does corticoid action specific to uremia cause the observed muscle degradation, and does inhibition of glucocorticoid action reduce the protein wasting?

Methods: RU 38486 was administered in a dose of 50 mg/kg/24 h for 48 h after operation to fasted bilaterally nephrectomized (BNX) male adult Wistar rats and sham operated (SHAM) controls. Protein turnover was evaluated by high performance liquid chromatography (HPLC) of amino acid efflux in sera from isolated perfused hindquarters of animals treated with RU 38486 versus untreated controls.

Polymorphisms of the insertion / deletion ACE and M235T AGT genes and hypertension: surprising new findings and meta-analysis of data.

Background: Essential hypertension is a common, polygenic, complex disorder resulting from interaction of several genes with each other and with environmental factors such as obesity, dietary salt intake, and alcohol consumption. Since the underlying genetic pathways remain elusive, currently most studies focus on the genes coding for proteins that regulate blood pressure as their physiological role makes them prime suspects. The present study examines how polymorphisms of the insertion/deletion (I/D) ACE and M235T AGT genes account for presence and severity of hypertension, and embeds the data in a meta-analysis of relevant studies.

Quantitative evaluation of recall and precision of CAT Crawler, a search engine specialized on retrieval of Critically Appraised Topics.

Background: Critically Appraised Topics (CATs) are a useful tool that helps physicians to make clinical decisions as the healthcare moves towards the practice of Evidence-Based Medicine (EBM). The fast growing World Wide Web has provided a place for physicians to share their appraised topics online, but an increasing amount of time is needed to find a particular topic within such a rich repository.

Methods: A web-based application, namely the CAT Crawler, was developed by Singapore's Bioinformatics Institute to allow physicians to adequately access available appraised topics on the Internet.

Active collaboration with primary care providers increases specialist referral in chronic renal disease.

Background: Late referral to specialist nephrological care is associated with increased morbidity, mortality, and cost. Consequently, nephrologists' associations recommend early referral. The recommendations' effectiveness remains questionable: 22-51% of referrals need renal replacement therapy (RRT) within 3-4 months.

Facilitating arrhythmia simulation: the method of quantitative cellular automata modeling and parallel running.

Background: Many arrhythmias are triggered by abnormal electrical activity at the ionic channel and cell level, and then evolve spatio-temporally within the heart. To understand arrhythmias better and to diagnose them more precisely by their ECG waveforms, a whole-heart model is required to explore the association between the massively parallel activities at the channel/cell level and the integrative electrophysiological phenomena at organ level.

Methods: We have developed a method to build large-scale electrophysiological models by using extended cellular automata, and to run such models on a cluster of shared memory machines.