The 55-kDa tumor necrosis factor receptor induces clustering of mitochondria through its membrane-proximal region

The cytokine tumor necrosis factor (TNF) activates diverse signaling molecules resulting in gene expression, differentiation, and/or cell death. Here we report a novel feature induced by TNF, namely translocation of mitochondria from a dispersed distribution to a perinuclear cluster. Mitochondrial translocation correlated with sensitivity to the cell death-inducing activity of TNF and was mediated by the 55-kDa TNF receptor (TNF-R55), but not by Fas, indicating that the signaling pathway requires a TNF-R55-specific but death domain-independent signal. Indeed, using L929 cells that express mutant TNF-R55, we showed that the membrane-proximal region of TNF-R55 was essential for signaling to mitochondrial translocation. In the absence of translocation, the cell death response was markedly delayed, pointing to a cooperative effect on cell death. Translocation of mitochondria, although dependent on the microtubules, was not imposed by the latter and was equally induced by TNF-independent immunoinhibition of the motor protein kinesin. Additionally, immunoinhibition with antibody directed against the tail domain of kinesin synergized with TNF-induced cell death. Based on this functional mimicry, we propose that a TNF-R55 membrane-proximal region-dependent signal impedes mitochondria-associated kinesin, resulting in cooperation with the TNF-R55 death domain-induced cytotoxic response and causing the observed clustering of mitochondria.     

Spread of vancomycin-resistant enterococci: differences between the United States and Europe

We investigate whether symptoms of pressure, tightness, and/or pain in the chest, neck, and/or throat after administration of the 5HT1B/1D agonist avitriptan were associated with objective impairment of the myocardial function on 12-lead electrocardiogram (ECG), continuous ECG (Holter) monitoring, and echocardiography. Migraine sufferers who in two-thirds of all attacks treated with sumatriptan had experienced chest/throat/neck symptoms were chosen for study. Baseline measures included vital signs, a 12-lead ECG and an echocardiogram. Patients (n = 51) who had no clinically significant abnormality at baseline received a high dose (150 mg) of avitriptan orally outside of a migraine attack. If pressure, tightness, and/or pain in the chest, neck, and/or throat occurred, an ECG was obtained, and a repeat echocardiogram was done while the symptoms were present in order to monitor for impairment of myocardial function. If symptoms of these types did not occur within 60 min after administration of the study drug, a second echocardiogram was obtained. Forty-five patients (88%) reported at least one adverse event and 23 (45%) experienced pressure, tightness, and/or pain in the chest, neck, and/or throat after administration of avitriptan. No clinically significant myocardial abnormalities were observed in any patients, even in those who had experienced the targeted symptoms. No other serious adverse event occurred. We concluded that the typical 5HT1B/1D agonist-induced chest/throat/neck symptoms are most unlikely to be of cardiovascular origin.     

Parental psychological control and dimensions of identity formation in emerging adulthood.

Longitudinal data were used to evaluate whether parental psychological control would have a negative impact on identity formation. Perceived psychological control and 4 identity dimensions (i.e., commitment making, exploration in breadth, identification with commitment, and exploration in depth) were assessed 5 times in a college sample. Associations between psychological control and identity (i.e., negative associations with both commitment dimensions and a positive association with exploration in breadth) were stable across time. Further, the developmental pathways of these constructs appeared to be correlated: Increases in psychological control were associated with simultaneous decreases in both commitment dimensions. Finally, reciprocal effects were found: Psychological control inhibited progress in both commitment dimensions, whereas exploration in breadth led to increased psychological control. The authors have provided suggestions for helping emerging adults to approach the task of identity formation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modification of venous stasis thrombosis in the rat by platelet-active drugs and by heparin

Incubation of adenovirus type 2 infected cells at 42 degrees C resulted in an inhibition of assembly of virus particles although all the major viral structural polypeptides and virus-induced cellular polypeptides so far identified were detected by electrophoretic analysis. Selective high salt-acid-urea extraction of low mol. wt. polypeptides revealed the absence of protein VII at 42 degrees C whereas precursor polypeptide P-VII and core protein V were found. Pulse-chase and temperature shift experiments indicated that cleavage of P-VII into VII was a reversible thermosensitive process, requiring de novo protein synthesis after shift-down to 37 degrees C. Virus particles assembled at 37 degrees C after transfer from 42 to 37 degrees C contained both viral DNA and polypeptides pre-labelled during the eclipse phase at 42 degrees C, including core protein VII.     

Hemoglobin Dakar = Hb Grady: demonstration by a new approach to the analysis of the tryptic core region of the alpha chain and oxygen equilibrium properties

Preliminary studies have suggested that in Hb Dakar, histidine alpha112 was substituted by a glutamine. A re-investigation on this hemoglobin is presented in this report. A structural study has been performed using a new approach to analyse the tryptic core region of the human hemoglobin alpha chain. After tryptic digestion of the aminoethylated alpha chain, a secondary digestion of the tryptic core was carried out with chymotrypsin and with another protease, thermolysin. Analyses of the chymotryptic and thermolytic peptides indicated that the structure of Hb Dakar was identical to that of Hb Grady previously described by Huisman et al. who showed the insertion of three amino acid residues in position alpha115 or alpha118. The insertion, which was localized near two residues involved in the alpha1beta1 contact, did not produce a dissociation into dimers. Functional studies demonstrated a a slightly increased oxygen affinity, a lowered cooperativity and a normal Bohr effect. The low amount of the abnormal hemoglobin (8%) may in part be explained by a slight instability of the molecule.     

Soil conditioners for stabilising trench backfill in an unstable loam soil of low permeability

Laboratory experiments were carried out to evaluate different soil conditioners for stabilising a loam soil, the aim being to increase the structural stability and the permeability of the backfill of drain trenches. Soil samples previously treated with different concentrations of polymer solutions or emulsions were dried to different moisture contents and packed in cylinders to determine the changes in water permeability. Identical soil samples were subjected to wet-sieving tests for different lengths of time. Loam soil samples treated with emulsions need to be air-dried to make them stable and highly permeable. At higher moisture contents the emulsions become ineffective because of the lack of coagulation between the soil particles. Polymer solutions are effective with regard to soil stability and water permeability even in situations where the soil remains wet. There is a fair agreement between the results of the wet-sieving test and those of the permeability test on loam soil samples. Those two tests were considered as reflecting the behaviour of the soil in a backfilled drain trench.     

Experiments on size effects in helicon resonances

Helicon resonance experiments are described in thin metal plates where the electron mean free path exceeds the thickness of the plate. The contribution of surface scattering to the damping of helicon resonances is quantitatively discussed (for the regime where the Doppler-shifted Cyclotron Resonance is unimportant). This yields a satisfactory explanation for the differences between theQ-values of the fundamental resonance and the first overtone that we observed in a thin-walled box of pure indium.     

Towards the understanding of plasma polymer film behaviour in ethanol: A multi-technique investigation

Plasma polymer films (PPFs) of allylamine are prepared varying the mean power injected in the plasma (P_mean). The PPF behaviour in ethanol is studied through the analysis of the PPF physico-chemistry and the composition of the resulting ethanol solutions. By Visible light Spectroscopic Ellipsometry (VISSE), it is observed that the well-known decrease of the PPF thickness (Δd) upon immersion decreases as a function of P_mean. This behaviour is attributed to an increase of the PPF cross-linking density (χ). By means of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and further statistical processing of the data by principal component analysis (PCA), we propose a method to discriminate the samples according to χ. A significant increase in the PPF oxygen content is also observed after immersion which is ascribed to reaction between ethanol molecules and trapped radicals of the PPF network. On the other hand, taking into account the specificities of the gas chromatography–mass spectrometry (GC–MS) method, the resulting ethanol solutions are demonstrated to be free of chemical species containing a number of carbon atoms ranging from 7 to 40. However, Δd (accounting for PPF restructuring) might come with the dissolution of PPF materials having less than 7 carbon atoms.     

Impact ionization in thin silicon diodes

We study the breakdown behavior of thin, abrupt silicon pin-diodes, using a low-power optical technique which can directly measure the avalanche multiplication factors even in the presence of large tunneling currents. Our measurements agree with a simple model for nonlocal avalanche generation, and we use this model to extend the breakdown predictions to a broad class of doped diodes similar to those found in the base-collector region of bipolar devices. Based on this analysis, we make quantitative estimates for the BV/sub CEO/ breakdown of modern Si and SiGe high-speed bipolar transistors.