Topography of rRNA in ribosomes. Effect of pancreatic RNAse on small ribosomal subunits]

The treatment of E. coli 30S ribosome subunits with pancreatic RNase under certain conditions resulted in the release of rRNA (about 15%). The subunit retained as a whole structure: sedimentation coefficient was unchanged and no protein release was observed. The released RNA is a set of oligonucleotides from 1 to 9 bases, except hepta- and octanenucleotides. Base composition of this RNA fraction is similar to 16S RNA, a slight increase of purines content being due to the specificity of nuclease. Analysis of isoplit content has revealed that a spliting of long oligonucleotides in stechiometric amount from 30S subunits takes place: one nonanucleotide, one hexanucleotide and two pentanucleotides.     

Poliovirus 2C protein determinants of membrane binding and rearrangements in mammalian cells.

Poliovirus protein 2C is a 329-amino acid-protein that is essential for viral RNA synthesis and may perform multiple functions. In infected cells, it is associated with virus-specific membrane vesicles. Recombinant 2C protein expressed in transfected cells has been shown to associate with and induce rearrangement of the intracellular membrane network. This study was designed to map the determinants of membrane binding and rearrangement in the 2C protein. Computer-assisted analysis of the protein sequence led to a prediction that the protein folds into a structure composed of three domains. Expression plasmids that encode each or combinations of these predicted domains were used to examine the abilities of the partial protein sequences to associate with intracellular membranes and to induce rearrangement of these membranes in HeLa cells. Biochemical fractionation procedures suggested that the N-terminal region of the protein was required for membrane association. Electron microscopic and immunoelectron microscopic observation showed that both the N- and C-terminal regions, but not the central portion, of 2C protein interact with intracellular membranes and induce major changes in their morphology. The central portion, when fused to the N-terminal region, altered the specific membrane architecture induced by the N-terminal region, giving rise to vesicles resembling those observed during poliovirus infection.     

Putative promoter region of rRNA operon from archaebacterium Halobacterium halobium.

The 100 bp sequence from the beginning of the 16S rRNA gene of archaebacterium Halobacterium halobium and the adjacent 800 bp upstream sequence were determined. Four long (80 bp) direct repeats were found in the region preceeding the structural gene of the 16S rRNA. These repeats are proposed to constitute the promoter region of the rRNA operon of H. halobium.     

Severe Painful Vaso-Occlusive Crises and Mortality in a Contemporary Adult Sickle Cell Anemia Cohort Study

Background

Frequent painful vaso-occlusive crises (VOCs) were associated with mortality in the Cooperative Study of Sickle Cell Disease (CSSCD) over twenty years ago. Modern therapies for sickle cell anemia (SCA) like hydroxyurea are believed to have improved overall patient survival. The current study sought to determine the relevance of the association between more frequent VOCs and death and its relative impact upon overall mortality compared to other known risk factors in a contemporary adult SCA cohort.

Methods

Two hundred sixty four SCA adults were assigned into two groups based on patient reported outcomes for emergency department (ED) visits or hospitalizations for painful VOC treatment during the 12 months prior to evaluation.

Results

Higher baseline hematocrit (p = 0.0008), ferritin (p = 0.005), and HDL cholesterol (p = 0.01) were independently associated with 1 or more painful VOCs requiring an ED visit or hospitalization for acute pain. During a median follow-up of 5 years, mortality was higher in the ED visit/hospitalization group (relative risk [RR] 2.68, 95% CI 1.1-6.5, p = 0.03). Higher tricuspid regurgitatant jet velocity (TRV) (RR 2.41, 95% CI 1.5-3.9, p < 0.0001), elevated ferritin (RR 4.00, 95% CI 1.8-9.0, p = 0.001) and lower glomerular filtration rate (RR=2.73, 95% CI 1.6-4.6, p < 0.0001) were also independent risk factors for mortality.

Conclusions

Severe painful VOCs remain a marker for SCA disease severity and premature mortality in a modern cohort along with other known risk factors for death including high TRV, high ferritin and lower renal function. The number of patient reported pain crises requiring healthcare utilization is an easily obtained outcome that could help to identify high risk patients for disease modifying therapies.

Trial Registration

ClinicalTrials.gov NCT00011648 http://clinicaltrials.gov/     

Miocene ostracods of Chuya and Kurai depressions of the southeastern Altai

Ostracods from the lacustrine–alluvial beds of intermontane troughs of the Altai Mountains are examined. Ostracods similar in species composition are recorded in the Lower–Middle Miocene of southeastern Kazakhstan. Changes in species composition and abundance of ostracods in the section of boreholes caused by changes in paleogeographical conditions of water bodies are analyzed. A new species of the genus Candona is described. For the previously known ostracod species, figures are provided.     

Effects of medium viscosity on kinetics of the enzymatic reaction catalyzed by bacterial RNase

Effects of medium viscosity on kinetic parameters of poly(U) hydrolysis catalyzed by RNase from Bac. intermedius 7P (binase) were studied in solutions of sucrose (4-50 wt. %) and glycerol (35-62 wt. %) in Tris--sodium acetate buffer (pH 7.5) at 25 degreesC. The rate constant of reaction kcat was practically unchanged over a wide range of viscosities (1-15 cP for sucrose and 2.5-3 cP for glycerol). In glycerol solutions, kcat slightly increased with viscosity increase from 4 to 10 cP. Addition of NaCl to the buffer medium resulted in an inhibitory effect of Na+ on kcat, prevented by 50% sucrose or 60% glycerol. It is concluded that binase-catalyzed poly(U) cleavage occurs through a "tense"-substrate mechanism, similarly to reactions catalyzed by alpha-chymotrypsin, trypsin, and laccase.     

A web server to locate periodicities in a sequence

Summary : FT is a tool written in C++, which implements the Fourier analysis method to locate periodicities in aminoacid or DNA sequences. It is provided for free public use on a WWW server with a Java interface. Availability : The server address is http://o2.db. uoa.gr/FT Contact : shamodr@atlas.uoa.gr      

Genetic Polymorphism of a Pelagic Fish Species,Little Baikal Oilfish <Emphasis Type="Italic">Comephorus dybowski</Emphasis>, Deduced from Analysis of Microsatellite Loci

Intraspecific genetic polymorphism of a Baikal Lake endemic, little Baikal oilfish (Comephorus dybowski Korotneff, 1905), was evaluated based on microsatellite analysis. Six microsatellite loci designed for the European sculpin, Cottus gobio, were used. Each locus was tested using 25 to 32 individuals from each of the Baikal basins (southern, middle, and northern). Analysis of genetic differentiation (F _ST and R _ST) revealed no statistical significant differences between the samples. The data showed that the target species was represented by a single panmictic stable population.__________Translated from Genetika, Vol. 41, No. 7, 2005, pp. 919–924.Original Russian Text Copyright © 2005 by Teterina, Sukhanova, Bogdanov, Anoshko, Kirilchik.