Symmetry of belladonna mottle virus: rotation function studies

Belladonna mottle virus, a spherical plant virus belonging to the tymovirus group, was crystallized by precipitation with polyethylene glycol 6000 in sodium citrate buffer (pH 5.6). The crystals belong to rhombohedral space group R3 (a \simeq 300 A, \alpha \simeq 60 °) with one molecule in the unit cell, and diffract X-rays to 3.5/~ resolution. Owing to the special interaxial angle of \simeq 60°, the lattice can also be described in terms of a pseudo-face-centred cubic cell. The face-centring vectors of the pseudo cell form the cell edges of the rhombohedral cell. The three-dimensional X-ray diffraction data on these crystals were collected using screenless oscillation photography to a resolution of 6 A. 37 842 independent reflections with {I/ \sigma (I) \geq 2-0} were measured on 51 filn ^pairs. The cell parameters were refined to a = 295.4A and \alpha = 59.86 ° by a postrefinement procedure. A rotation function was calculated using data between 11 and 13 A resolution. The function unambiguously reveals the particle icosahedral symmetry and orientation in the unit cell. The body diagonals of the pseudo-cubic cell are nearly tetrahedral. The icosahedral particle also has a set of tetrahedrally related threefold axes. The particle orientation is such that these two sets can be made coincident by a rotation of \simeq 180 ° about the rhombohedral [111] direction

Stability of belladonna mottle virus particles: the role of polyamines and calcium

The stability of belladonna mottle virus (BDMV) has been studied with respect to elevated pH and to freezing and thawing. BDMV, purified by a modified procedure, was stable at alkaline pH, in contradiction to earlier reports. This difference in the stability could be attributed to the presence of 90 to 140 molecules of spermidine, 20 to 50 molecules of putrescine and 500 to 900 calcium ions in each virus particle. The polyamines could be easily exchanged with other cations such as potassium or caesium and this resulted in a loss of particle stability. These cations may therefore play a role in maintaining the integrity of particle structure. The formation of empty protein shells as a result of freezing and thawing BDMV particles parallels earlier observations on turnip yellow mosaic virus particles

Surgical site infection rates in six cities of India: findings of the International Nosocomial Infection Control Consortium (INICC)

Surgical site infections are a threat to patient safety. However, in India, data on their rates stratified by surgical procedure are not available. From January 2005 to December 2011, the International Nosocomial Infection Control Consortium (INICC) conducted a cohort prospective surveillance study on surgical site infections in 10 hospitals in 6 Indian cities. CDC National Healthcare Safety Network (CDC-NHSN) methods were applied and surgical procedures were classified into 11 types, according to the ninth edition of the International Classification of Diseases. We documented 1189 surgical site infections, associated with 28 340 surgical procedures (4.2%; 95% CI: 4.0-4.4). Surgical site infections rates were compared with INICC and CDC-NHSN reports, respectively: 4.3% for coronary bypass with chest and donor incision (4.5% vs 2.9%); 8.3% for breast surgery (1.7% vs 2.3%); 6.5% for cardiac surgery (5.6% vs 1.3%); 6.0% for exploratory abdominal surgery (4.1% vs 2.0%), among others. In most types of surgical procedures, surgical site infections rates were higher than those reported by the CDC-NHSN, but similar to INICC. This study is an important advancement towards the knowledge of surgical site infections epidemiology in the participating Indian hospitals that will allow us to introduce targeted interventions

Device-Associated Infection Rates in 20 Cities of India, Data Summary for 2004–2013: Findings of the International Nosocomial Infection Control Consortium

To report the International Nosocomial Infection Control Consortium surveillance data from 40 hospitals (20 cities) in India 2004-2013. Surveillance using US National Healthcare Safety Network's criteria and definitions, and International Nosocomial Infection Control Consortium methodology. We collected data from 236,700 ICU patients for 970,713 bed-days Pooled device-associated healthcare-associated infection rates for adult and pediatric ICUs were 5.1 central line-associated bloodstream infections (CLABSIs)/1,000 central line-days, 9.4 cases of ventilator-associated pneumonia (VAPs)/1,000 mechanical ventilator-days, and 2.1 catheter-associated urinary tract infections/1,000 urinary catheter-days In neonatal ICUs (NICUs) pooled rates were 36.2 CLABSIs/1,000 central line-days and 1.9 VAPs/1,000 mechanical ventilator-days Extra length of stay in adult and pediatric ICUs was 9.5 for CLABSI, 9.1 for VAP, and 10.0 for catheter-associated urinary tract infections. Extra length of stay in NICUs was 14.7 for CLABSI and 38.7 for VAP Crude extra mortality was 16.3% for CLABSI, 22.7% for VAP, and 6.6% for catheter-associated urinary tract infections in adult and pediatric ICUs, and 1.2% for CLABSI and 8.3% for VAP in NICUs Pooled device use ratios were 0.21 for mechanical ventilator, 0.39 for central line, and 0.53 for urinary catheter in adult and pediatric ICUs; and 0.07 for mechanical ventilator and 0.06 for central line in NICUs. Despite a lower device use ratio in our ICUs, our device-associated healthcare-associated infection rates are higher than National Healthcare Safety Network, but lower than International Nosocomial Infection Control Consortium Report

Crystal structures of the N-terminal kinase domain of human RSK1 bound to three different ligands: Implications for the design of RSK1 specific inhibitors

The p90 ribosomal S6 kinases (RSKs) also known as MAPKAP-Ks are serine/threonine protein kinases that are activated by ERK or PDK1 and act as downstream effectors of mitogen-activated protein kinase (MAPK). RSK1, a member of the RSK family, contains two distinct kinase domains in a single polypeptide chain, the regulatory C-terminal kinase domain (CTKD) and the catalytic N-terminal kinase domain (NTKD). Autophosphorylation of the CTKD leads to activation of the NTKD that subsequently phosphorylates downstream substrates. Here we report the crystal structures of the unactivated RSK1 NTKD bound to different ligands at 2.0 Å resolution. The activation loop and helix αC, key regulatory elements of kinase function, are disordered. The DFG motif of the inactive RSK1 adopts an “active-like” conformation. The β-PO4 group in the AMP–PCP complex adopts a unique conformation that may contribute to inactivity of the enzyme. Structures of RSK1 ligand complexes offer insights into the design of novel anticancer agents and into the regulation of the catalytic activity of RSKs