Troponin I testing in dialysis patients presenting to the emergency room: does troponin I predict the 30-day outcome?

Background: Troponins are often measured in acutely ill chronic dialysis patients admitted to the emergency room, irrespective of their clinical presentation. The significance of an elevated troponin level in this setting is unclear.

Methods: We identified all chronic dialysis patients presenting over 1 year to a tertiary care hospital emergency room who also had at least one cardiac troponin I (cTnI) level determination.

Effects of antidepressant treatment on gene expression profile in mouse brain: cell type-specific transcription profiling using laser microdissection and microarray analysis.

A gene expression study of mice treated with the tricyclic antidepressant amitriptyline was performed. To enable the detection of cell type-specific expression changes, laser-microdissected nucleus accumbens was analysed after 4 and 28 days of treatment. After 4 days of treatment no significantly regulated genes could be detected in this study.

Molecular characterisation of non-absorptive and absorptive enterocytes in human small intestine.

Background And Aims: Perturbation of differentiation of the crypt-villus axis of the human small intestine is associated with several intestinal disorders of clinical importance. At present, differentiation of small intestinal enterocytes in the crypt-villus axis is not well characterised.

Subjects And Methods: Expression profiling of microdissected enterocytes lining the upper part of crypts or the middle of villi was performed using the Affymetrix X3P arrays and several methods for confirmation.

SorLA signaling by regulated intramembrane proteolysis.

The single-transmembrane receptor SorLA/LR11 contains binding domains typical for lipoprotein receptors and a VPS10 domain, which binds the neuropeptide head-activator. This undecapeptide enhances proliferation of neuronal precursor cells in a SorLA-dependent manner. Using specific inhibitors we found previously that head activator activates shedding of SorLA by the metalloprotease TACE close to the transmembrane domain releasing the large extra-cellular part of the receptor.

Enhancing instance-based classification with local density: a new algorithm for classifying unbalanced biomedical data.

Motivation: Classification is an important data mining task in biomedicine. In particular, classification on biomedical data often claims the separation of pathological and healthy samples with highest discriminatory performance for diagnostic issues. Even more important than the overall accuracy is the balance of a classifier, particularly if datasets of unbalanced class size are examined.

Identification of novel diagnostic markers for choroid plexus tumors: a microarray-based approach.

To identify specific markers for the diagnosis of choroid plexus tumors, gene expression profiles of choroid plexus epithelial cells (n = 8) and ependymal cells (n = 6) microdissected from human autopsy brains as well as choroid plexus papilloma tissue were investigated using DNA microarrays. Protein expression of genes overexpressed in choroid plexus was evaluated in normal choroid plexus, choroid plexus papilloma, choroid plexus carcinoma, other primary brain tumors, and cerebral metastases. Forty-six genes found to be overexpressed in normal choroid plexus epithelial cells were also present in choroid plexus papilloma.

Laser microdissection in CNS research.

The complexity of the brain makes the investigation of anatomically defined regions using manual dissection techniques problematic. With these manual dissection techniques, only a mixture of many different cell types can be obtained. This leads to averaging the contents of all the different cell types, making it nearly impossible to observe effects that are specific to one type of cell.

Effect of endocardial trabeculae on left ventricular measurements and measurement reproducibility at cardiovascular MR imaging.

Purpose: To prospectively assess the effect of including or excluding endocardial trabeculae in left ventricular (LV) measurements and the reproducibility of these measurements at cine cardiovascular magnetic resonance (MR) imaging with true fast imaging with steady-state precession (FISP).

Materials And Methods: The study was approved by the local ethics committee, and each subject gave informed consent before participating. Twenty healthy subjects and 20 consecutive patients underwent 1.

Functional cluster analysis of CT perfusion maps: a new tool for diagnosis of acute stroke?

CT perfusion imaging constitutes an important contribution to the early diagnosis of acute stroke. Cerebral blood flow (CBF), cerebral blood volume (CBV) and time-to-peak (TTP) maps are used to estimate the severity of cerebral damage after acute ischemia. We introduce functional cluster analysis as a new tool to evaluate CT perfusion in order to identify normal brain, ischemic tissue and large vessels.

Emerin expression in early development of Xenopus laevis.

Emerin is an integral protein of the inner nuclear membrane in the majority of differentiated vertebrate cells. In humans, deficiency of emerin causes a progressive muscular dystrophy of the Emery-Dreifuss type. The physiological role of emerin is poorly understood.

Modelling of classification rules on metabolic patterns including machine learning and expert knowledge.

Machine learning has a great potential to mine potential markers from high-dimensional metabolic data without any a priori knowledge. Exemplarily, we investigated metabolic patterns of three severe metabolic disorders, PAHD, MCADD, and 3-MCCD, on which we constructed classification models for disease screening and diagnosis using a decision tree paradigm and logistic regression analysis (LRA). For the LRA model-building process we assessed the relevance of established diagnostic flags, which have been developed from the biochemical knowledge of newborn metabolism, and compared the models' error rates with those of the decision tree classifier.

Hu-K4 is a ubiquitously expressed type 2 transmembrane protein associated with the endoplasmic reticulum.

Hu-K4 is a human protein homologous to the K4L protein of vaccinia virus. Due to the presence of two HKD motifs, Hu-K4 was assigned to the family of Phospholipase D proteins although so far no catalytic activity has been shown. The Hu-K4 mRNA is found in many human organs with highest expression levels in the central nervous system.

Use and outcomes of peritoneal dialysis among Aboriginal people in Canada.

There has been a dramatic increase in the incidence of ESRD among Aboriginal people in North America. Although peritoneal dialysis (PD) seems to be the dialysis modality of choice for this often rural-dwelling population, few data exist to confirm this. This study was conducted to evaluate rates of PD use, technique failure, and mortality among incident Aboriginal dialysis patients.

Death and renal transplantation among Aboriginal people undergoing dialysis.

Background: Despite the increase in the number of Aboriginal people with end-stage renal disease around the world, little is known about their health outcomes when undergoing renal replacement therapy. We evaluated differences in survival and rate of renal transplantation among Aboriginal and white patients after initiation of dialysis.

Methods: Adult patients who were Aboriginal or white and who commenced dialysis in Alberta, Saskatchewan or Manitoba between Jan.

Supervised machine learning techniques for the classification of metabolic disorders in newborns.

Motivation: During the Bavarian newborn screening programme all newborns have been tested for about 20 inherited metabolic disorders. Owing to the amount and complexity of the generated experimental data, machine learning techniques provide a promising approach to investigate novel patterns in high-dimensional metabolic data which form the source for constructing classification rules with high discriminatory power.

Results: Six machine learning techniques have been investigated for their classification accuracy focusing on two metabolic disorders, phenylketo nuria (PKU) and medium-chain acyl-CoA dehydrogenase deficiency (MCADD).

Murine pancreatic tumor cell line TD2 bears the characteristic pattern of genetic changes with two independently amplified gene loci.

TGFalpha/p53(+/-) transgenic mice represent a genetically engineered mouse model for pancreatic adenocarcinoma. The tumors develop a characteristic pattern of secondary genetic changes. From one of these tumors, the permanent cell line TD2 was established.

No evidence of tumour cells in blood of patients with glioma.

Background: Although clinically apparent systemic metastases of gliomas are very rare, reports of gliomas developing in recipient's transplanted organs have suggested that haematogenous spread might be more common.

Methods: This report describes a newly developed, sensitive real time quantitative reverse transcription polymerase chain reaction assay for the detection of mRNA encoding glial fibrillary acidic protein (GFAP). Blood from 10 patients with astrocytoma and 10 patients with glioblastoma was analysed.

Increased frequency of HLA A2/DR4 and A2/DR8 haplotypes in young saskatchewan aboriginal people with diabetic end-stage renal disease.

Aims: To determine the association of HLA with diabetic end-stage renal disease (DESRD) in Saskatchewan aboriginal people.

Methods: This was a retrospective study of HLA profiles in four groups of Saskatchewan residents with ESRD diagnosed from 1980 to 1998: aboriginal people with and without DESRD, and non-aboriginal people with and without DESRD. The aboriginal DESRD group was also subdivided into those 50 years of age.

Facile asymmetric synthesis of the core nuclei of xanthanolides, guaianolides, and eudesmanolides.

[reaction: see text] Bicyclic and tricyclic gamma-butyrolactones with 5,7-, 5,6,5-, 5,6,6-, or 5,7,5-fused ring systems, being found in xanthanolides, eudesmanolides, and guaianolides, were readily synthesized from methyl furan-2-carboxylic acid. Key steps were a copper(I)-catalyzed asymmetric cyclopropanation, Sakurai allylations, intramolecular ene reactions, and ring-closing metathesis reactions.

Enantioselective synthesis of paraconic acids.

The development of a new method for the enantioselective synthesis of disubstituted gamma-butyrolactones is reported. Based on this strategy, the total synthesis of three paraconic acids, that is (-)-roccellaric acid, (-)-nephrosteranic acid and (-)-protopraesorediosic acid, and the formal total synthesis of (-)-methylenolactocin and (-)-protolichesterinic acid is described, which are important because of their antibiotic and antitumor properties. Key steps of the synthesis are copper(I)-catalyzed asymmetric cyclopropanations of furans, highly diastereoselective Sakurai allylations, Lewis acid or Lewis base catalyzed retroaldol/lactonization cascades, and ruthenium(II)-catalyzed, intermolecular cross metathesis reactions.

Barriers to blood pressure control and angiotensin enzyme inhibitor use in Canadian patients with chronic renal insufficiency.

Background: Current recommendations for the management of chronic renal insufficiency (CRI) include the use of angiotensin-converting enzyme inhibitors (ACEI) and achieving target blood pressure control. We designed this study to describe the use of these therapeutic strategies, and to investigate barriers to their implementation.

Methods: This was a prospective study of 304 consecutive CRI patients, seen at follow-up in four nephrology clinics across Canada.

Enantioselective synthesis of (-)-roccellaric acid.

[reaction in text] A new strategy for the synthesis of anti-4,5-disubstituted gamma-butyrolactones starting from inexpensive furan-2-carboxylic methyl ester was developed. By applying this methodology, the enantioselective synthesis of (-)-roccellaric acid ((-)-17) was accomplished using a copper(I)-catalyzed asymmetric cyclopropanation, a tin(IV)-catalyzed retroaldol/lactonization sequence of cyclopropanols, and a ruthenium-catalyzed intermolecular metathesis reaction as key steps.

Effects of chiral fragrances on human autonomic nervous system parameters and self-evaluation.

The effects of chiral fragrances (enantiomers of limonene and carvone) on the human autonomic nervous system (ANS) and on self-evaluation were studied in 20 healthy volunteers. Each fragrance was administered to each subject by inhalation using an A-A-B design. Individuals were tested in four separate sessions; in one session one fragrance was administered.