Thromboprophylaxis adherence to the ninth edition of American college of chest physicians antithrombotic guidelines in a tertiary care centre: a cross-sectional study.

RATIONALE: Venous thromboembolic disease is a source of significant morbidity in hospitalized patients. The American College of Chest Physicians published the ninth edition of antithrombotic therapy and prevention guidelines (AT9) in 2012, addressing thromboprophylaxis in hospitalized patients. A notable difference from previous guidelines was utilization of risk assessment models for thrombosis and bleeding to classify patients into risk categories. AIM: This study's objective was to evaluate thromboprophylaxis adherence to AT9 guidelines in a population of patients at the Centre intégré universitaire de santé et de service sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke. METHOD: A cross-sectional study at the Centre intégré universitaire de santé et de service sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke was performed between June and December 2012. Patients' risk factors for thrombosis and bleeding, and thromboprophylaxis use were documented. The Padua and Caprini models were used to determine thrombotic risk, and the International Medical Prevention Registry on Venous Thromboembolism bleeding risk score was used for bleeding risk. RESULTS: A total of 290 patients were included for analysis. Overall, 200 patients (70%) received some form of thromboprophylaxis. However, according to AT9 guidelines, only 162 patients (55.9%) received recommended prophylaxis, 91 (31.4%) had overuse of prophylaxis and 37 (12.7%) had underuse of prophylaxis. Appropriate prophylaxis use was higher in surgical (61.8%) than in medical (46.7%) patients. CONCLUSIONS: There was a high rate of inappropriate thromboembolic prophylaxis in our centre according to AT9 guidelines, mostly from overuse of prophylaxis. Utilization of risk assessment models in AT9 guidelines adds to the complexity of physician's decisions to prescribe thromboprophylaxis and needs further validation.

Microarrays: biotechnology's discovery platform for functional genomics.

Advances in microarray technology enable massive parallel mining of biological data, with biological chips providing hybridization-based expression monitoring, polymorphism detection and genotyping on a genomic scale. Microarrays containing sequences representative of all human genes may soon permit the expression analysis of the entire human genome in a single reaction. These 'genome chips' will provide unprecedented access to key areas of human health, including disease prognosis and diagnosis, drug discovery, toxicology, aging, and mental illness. Microarray technology is rapidly becoming a central platform for functional genomics.

Real-time detection of DNA hybridization and melting on oligonucleotide arrays by using optical wave guides.

The challenge of the Human Genome Project is to increase the rate of DNA sequence acquisition by two orders of magnitude to complete sequencing of the human genome by the year 2000. The present work describes a rapid detection method using a two-dimensional optical wave guide that allows measurement of real-time binding or melting of a light-scattering label on a DNA array. A particulate label on the target DNA acts as a light-scattering source when illuminated by the evanescent wave of the wave guide and only the label bound to the surface generates a signal. Imaging/visual examination of the scattered light permits interrogation of the entire array simultaneously. Hybridization specificity is equivalent to that obtained with a conventional system using autoradiography. Wave guide melting curves are consistent with those obtained in the liquid phase and single-base discrimination is facile. Dilution experiments showed an apparent lower limit of detection at 0.4 nM oligonucleotide. This performance is comparable to the best currently known fluorescence-based systems. In addition, wave guide detection allows manipulation of hybridization stringency during detection and thereby reduces DNA chip complexity. It is anticipated that this methodology will provide a powerful tool for diagnostic applications that require rapid cost-effective detection of variations from known sequences.

Structural and kinetic studies of the Fab fragment of a monoclonal anti-spin label antibody by nuclear magnetic resonance.

Nuclear magnetic resonance has been used to study the structure of the anti-spin label antibody AN02 combining site and kinetic rates for the hapten-antibody reaction. The association reaction for the hapten dinitrophenyl-diglycine (DNP-diGly) is diffusion-limited. The activation enthalpy for association, 5.1 kcal/mol, is close to the activation enthalpy for diffusion in water. Several reliable resonance assignments have been made with the aid of recently reported crystal structure. Structural data deduced from the nuclear magnetic resonance (n.m.r.) spectra compare favorably with the crystal structure in terms of the combining site amino acid composition, distances of tyrosine residues from the unpaired electron of the hapten, and residues in direct contact with the hapten. Evidence is presented that a single binding site region tyrosine residue can assume two distinct conformations on binding of DNP-diGly. The AN02 antibody is an autoantibody. Dimerization of the Fab fragments is blocked by the hapten DNP-diGly. The n.m.r. spectra suggests that some of the amino acid residues involved in the binding of the DNP-hapten are also involved in the Fab dimerization.