A bacterial clone carrying sequences coding for elongation factor EF-1 alpha from Artemia

A bacterial cDNA clone was identified carrying one third of the nucleotides coding for elongation factor EF-1 alpha from the brine shrimp Artemia. The sequence of codons corresponds with the known sequence of amino acids of EF-1 alpha in the region involved.     

BRE over-expression promotes growth of hepatocellular carcinoma

BRE, also known as TNFRSF1A modulator and BRCC45, is an evolutionarily highly conserved protein. It is a death receptor-associated protein in cytoplasm and a component of BRCA1/2-containing DNA repair complex in nucleus. BRE was found to have anti-apoptotic activity. Over-expression of BRE by transfection promoted survival of cell lines against apoptotic induction; whereas depletion of the protein by siRNA resulted in the opposite. In vivo anti-apoptotic activity of BRE was demonstrated by significant attenuation of Fas-induced acute fulminant hepatitis in transgenic mice expressing the human protein specifically in the liver. BRE was also implicated in tumor promotion by the accelerated tumor growth of Lewis Lung carcinoma transfected with human BRE; and by high expression of BRE specifically in the tumoral regions of human hepatocellular carcinoma (HCC). The present study was to test directly if transgenic expression of BRE in livers could promote HCC development in neonatal diethylnitrosamine model. By 8 months after tumor induction, the maximal sizes of tumor nodules of transgenic mice were significantly larger than those of the non-transgenic controls, although the numbers of tumor nodules between the two groups did not significantly differ. Importantly, as in human HCC, the mouse endogenous BRE level was up-regulated in mouse HCC nodules. These results show that BRE over-expression can indeed promote growth, though not initiation, of liver tumors. Furthermore, the common occurrence of BRE over-expression in human and mouse HCC suggests that up-regulation of BRE is functionally important in liver tumor development.     

Rat atrial natriuretic factor: Isolation,structure and biological activities of four major peptides

Four peptides possessing both natriuretic activity and smooth muscle relaxant activity were isolated from rat atrium and their amino acid sequences determined. The four peptides designated ANF-I, ANF-II, ANF-III and ANF-IV containing 35, 31, 30 and 25 amino acid residues, respectively, were obtained in a molar ratio of 4:60:20:16. The predominant species ANF-II, which may represent the native form of ANF, has the following sequence: (H₂N)-G-P-R-S-L-R-R-S-S-C-F-G-G-R-I-D-R-I-G-A-Q-S-G-L-G-C-N-S-F-R-Y-(COOH) in which Cys-10 and Cys-26 are disulfide linked. Cleavage of the aspartyl linkage at position 16 by staphylococcal protease caused complete inactivation, indicating that the ring conformation is essential. The dose-response relationships determined for the four pepdides in relaxing norepinephrine-induced contraction of rabbit thoracic aorta showed half-maximum relaxation at concentrations ranging from 1.5 × 10^?9 to 2.5 × 10^?9 M. Comparable dose-response relationships were observed in relaxation of carbacol-induced contraction of chick rectum strips as tested with ANF-II and ANF-IV.     

Non‐muscle myosin IIB helps mediate TNF cell death signaling independent of actomyosin contractility (AMC)

Non‐muscle myosin II (NM II) helps mediate survival and apoptosis in response to TNF‐alpha (TNF), however, NM II's mechanism of action in these processes is not fully understood. NM II isoforms are involved in a variety of cellular processes and differences in their enzyme kinetics, localization, and activation allow NM II isoforms to have distinct functions within the same cell. The present study focused on isoform specific functions of NM IIA and IIB in mediating TNF induced apoptosis. Results show that siRNA knockdown of NM IIB, but not NM IIA, impaired caspase cleavage and nuclear condensation in response to TNF. NM II's function in promoting cell death signaling appears to be independent of actomyosin contractility (AMC) since treatment of cells with blebbistatin or cytochalasin D failed to inhibit TNF induced caspase cleavage. Immunoprecipitation studies revealed associations of NM IIB with clathrin, FADD, and caspase 8 in response to TNF suggesting a role for NM IIB in TNFR1 endocytosis and the formation of the death inducing signaling complex (DISC). These findings suggest that NM IIB promotes TNF cell death signaling in a manner independent of its force generating property. J. Cell. Biochem. 9999: 1365–1375, 2010. © 2010 Wiley‐Liss, Inc.     

Manganese-54 accumulation by Chlorella spp., Daphnia magna and yellow perch (Perca flavescens)

Concentration factor and biological half-life of ⁵⁴Mn were determined in three species representing an ecologically and economically important food chain. Green algae (Chlorella spp.), Daphnia magna and yellow perch (Perca flavescens) were exposed to ⁵⁴Mn in water and assayed for ⁵⁴Mn uptake. Steady state concentration factors computed from the laboratory data for algae, Daphnia and perch were 4230, 17 000 and 11, respectively. Respective biological half-lives were 1.6, 1.2 and 8.3 days.     

Analysis of Multiply Matched Retrospective Studies When Risk Factor Under Study is Discrete,With Two or More Levels

The odds ratio is known to closely approximate the relative risk when the disease is rare. Logistic regression models are often used to estimate such odds ratios, but here a different model is used which avoids the assumptions implicit in logistic modelling; it also has the advantage of providing a test of homogeneity for odds rat os in situations where the logistic model cannot.     

Activation of pigeon erythrocyte adenylate cyclase by cholera toxin partial purification of an essential macromolecular factor from horse erythrocyte cytosol

A cytosolic, macromolecular factor required for the cholera toxin-dependent activation of pigeon erythrocyte adenylate cyclase and cholera toxin-dependent ADP-ribosylation of a membrane-bound 43 000 dalton polypeptide has been purified 1100-fold from horse erythrocyte cytosol using organic solvent precipitation and heat treatment. This factor, 13 000 daltons, does not absorb to anionic or cationic exchange resins, is sensitive to trypsin or 10% trichloroacetic acid and is not extractable by diethyl ether. Activation of adenylate cyclase by cholera toxin requires the simultaneous presence of ATP (including possible trace GTP), NAD⁺, dithiothreitol, cholera toxin, membranes and the cytosolic macromolecular factor. Reversal of cholera toxin activation of adenylate cyclase, and of the toxin-dependent ADP-ribosylation, requires the presence of the cytosolic factor. The ability of the purified cytosolic factor to influence the hormonal sensitivity of liver membrane adenylate cyclase may provide clues to its physiological functions.