Traumatic brain injury

There is an increasing incidence of military traumatic brain injury (TBI), and similar injuries are seen in civilians in war zones or terrorist incidents. Indeed, blast-induced mild TBI has been referred to as the signature injury of the conflicts in Iraq and Afghanistan. Assessment involves schemes that are common in civilian practice but, in common with civilian TBI, takes little account of information available from modern imaging (particularly diffusion tensor magnetic resonance imaging) and emerging biomarkers. The efficient logistics of clinical care delivery in the field may have a role in optimizing outcome. Clinical care has much in common with civilian TBI, but intracranial pressure monitoring is not always available, and protocols need to be modified to take account of this. In addition, severe early oedema has led to increasing use of decompressive craniectomy, and blast TBI may be associated with a higher incidence of vasospasm and pseudoaneurysm formation. Visual and/or auditory deficits are common, and there is a significant risk of post-traumatic epilepsy. TBI is rarely an isolated finding in this setting, and persistent post-concussive symptoms are commonly associated with post-traumatic stress disorder and chronic pain, a constellation of findings that has been called the polytrauma clinical triad.     

Trs65p, a subunit of the Ypt1p GEF TRAPPII, interacts with the Arf1p exchange factor Gea2p to facilitate COPI-mediated vesicle traffic

The TRAPP complexes are multimeric guanine exchange factors (GEFs) for the Rab GTPase Ypt1p. The three complexes (TRAPPI, TRAPPII, and TRAPPIII) share a core of common subunits required for GEF activity, as well as unique subunits (Trs130p, Trs120p, Trs85p, and Trs65p) that redirect the GEF from the endoplasmic reticulum-Golgi pathway to different cellular locations where TRAPP mediates distinct membrane trafficking events. Roles for three of the four unique TRAPP subunits have been described before; however, the role of the TRAPPII-specific subunit Trs65p has remained elusive. Here we demonstrate that Trs65p directly binds to the C-terminus of the Arf1p exchange factor Gea2p and provide in vivo evidence that this interaction is physiologically relevant. Gea2p and TRAPPII also bind to the yeast orthologue of the γ subunit of the COPI coat complex (Sec21p), a known Arf1p effector. These and previous findings reveal that TRAPPII is part of an Arf1p GEF-effector loop that appears to play a role in recruiting or stabilizing TRAPPII to membranes. In support of this proposal, we show that TRAPPII is more soluble in an arf1Δ mutant.     

European society of intensive care medicine study of therapeutic hypothermia (32-35°C) for intracranial pressure reduction after traumatic brain injury (the Eurotherm3235Trial)

Background

Severe malaria remains a major cause of global morbidity and mortality. Despite the use of potent anti-parasitic agents, the mortality rate in severe malaria remains high. Adjunctive therapies that target the underlying pathophysiology of severe malaria may further reduce morbidity and mortality. Endothelial activation plays a central role in the pathogenesis of severe malaria, of which angiopoietin-2 (Ang-2) has recently been shown to function as a key regulator. Nitric oxide (NO) is a major inhibitor of Ang-2 release from endothelium and has been shown to decrease endothelial inflammation and reduce the adhesion of parasitized erythrocytes. Low-flow inhaled nitric oxide (iNO) gas is a US FDA-approved treatment for hypoxic respiratory failure in neonates.

Methods/Design

This prospective, parallel arm, randomized, placebo-controlled, blinded clinical trial compares adjunctive continuous inhaled nitric oxide at 80 ppm to placebo (both arms receiving standard anti-malarial therapy), among Ugandan children aged 1-10 years of age with severe malaria. The primary endpoint is the longitudinal change in Ang-2, an objective and quantitative biomarker of malaria severity, which will be analysed using a mixed-effects linear model. Secondary endpoints include mortality, recovery time, parasite clearance and neurocognitive sequelae.

Discussion

Noteworthy aspects of this trial design include its efficient sample size supported by a computer simulation study to evaluate statistical power, meticulous attention to complex ethical issues in a cross-cultural setting, and innovative strategies for safety monitoring and blinding to treatment allocation in a resource-constrained setting in sub-Saharan Africa.

Trial Registration

ClinicalTrials.gov Identifier: NCT01255215     

Constant-flow ventilation in pigs

Constant-flow ventilation (CFV) is a ventilatory technique in which physiological blood gases can be maintained in dogs by a constant flow of fresh gas introduced via two catheters placed in the main-stem bronchi (J. Appl. Physiol. 53: 483-489, 1982). High-velocity gas exiting from the catheters can create uneven pressure differences in adjacent lung segments, and these pressure differences could lead to gas flow through collateral channels. To examine this hypothesis, we studied CFV in pigs, animals known to have a high resistance to collateral ventilation. In three pigs we examined steady-state gas exchange, and in six others we studied unsteady gas exchange at three flow rates (20, 35, and 50 l/min) and three catheter positions (0.5, 1.5, and 2.5 cm distal to the tracheal carina). During steady-state runs we were unable to attain normocapnia; the arterial CO2 partial pressure (PaCO2) was approximately 300 Torr at all flow rates and all catheter positions, compared with 20-50 Torr at similar flows and positions in dogs studied previously. The initial unsteady gas-exchange experiments indicated no consistent effect of catheter position or flow rate on the rate of rise of PaCO2. In three other pigs, the rates of rise of PaCO2 were compared with the rates observed with apneic oxygenation (AO). At the maximum flow and deepest position, the rate of rise of PaCO2 was lower during CFV than during AO. These data suggest that flow through collateral channels might be important in producing adequate gas transport during CFV; however, other factors such as airway morphometry and the effects of cardiogenic oscillations may explain the differences between the results in pigs and dogs.     

Carboxyl terminal domain basic amino acids of mycobacterial topoisomerase I bind DNA to promote strand passage

Bacterial DNA topoisomerase I (topoI) carries out relaxation of negatively supercoiled DNA through a series of orchestrated steps, DNA binding, cleavage, strand passage and religation. The N-terminal domain (NTD) of the type IA topoisomerases harbor DNA cleavage and religation activities, but the carboxyl terminal domain (CTD) is highly diverse. Most of these enzymes contain a varied number of Zn²⁺ finger motifs in the CTD. The Zn²⁺ finger motifs were found to be essential in Escherichia coli topoI but dispensable in the Thermotoga maritima enzyme. Although, the CTD of mycobacterial topoI lacks Zn²⁺ fingers, it is indispensable for the DNA relaxation activity of the enzyme. The divergent CTD harbors three stretches of basic amino acids needed for the strand passage step of the reaction as demonstrated by a new assay. We also show that the basic amino acids constitute an independent DNA-binding site apart from the NTD and assist the simultaneous binding of two molecules of DNA to the enzyme, as required during the catalytic step. Although the NTD binds to DNA in a site-specific fashion to carry out DNA cleavage and religation, the basic residues in CTD bind to non-scissile DNA in a sequence-independent manner to promote the crucial strand passage step during DNA relaxation. The loss of Zn²⁺ fingers from the mycobacterial topoI could be associated with Zn²⁺ export and homeostasis.     

Protective effect of curcumin on γ-radiation induced DNA damage and lipid peroxidation in cultured human lymphocytes

The present work is aimed at evaluating the radioprotective effect of curcumin, a naturally occurring phenolic compound on γ-radiation induced toxicity. The cellular changes were estimated by using lipid peroxidative indices like thiobarbituric acid reactive substances (TBARS), the antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH). The DNA damage was analysed by using cytokinesis blocked micronucleus assay and dicentric aberration (DC). The γ-radiation at different doses (1, 2 and 4 Gy) were found to significantly increase micronuclei (MN), DC frequencies and TBARS level whereas the levels of GSH and antioxidant enzymes were significantly decreased. The maximum damage to lymphocytes was observed at 4 Gy irradiation. Curcumin pretreatment (1, 5 and 10 μg/ml) significantly decreased the frequency of MN and DC. The levels of TBARS decreased and activities of SOD, CAT and GPx significantly increased along with GSH levels. At 1 Gy irradiation all the concentrations of curcumin (1, 5 and 10 μg/ml) significantly protected the lymphocytes from radiation damage. At 2 Gy irradiation, 5 and 10 μg/ml of curcumin showed significant radioprotection. Since the highest damage was observed at 4 Gy irradiation both 1 and 5 μg/ml of curcumin pretreatment were not sufficient to protect the lymphocytes from radiation damage but 10 μg/ml of curcumin significantly protected the cultured lymphocytes from radiation damage. Thus, pretreatment with curcumin gives protection to lymphocytes against γ-radiation induced cellular damage.     

Overview of the HUPO Plasma Proteome Project: results from the pilot phase with 35 collaborating laboratories and multiple analytical groups, generating a core dataset of 3020 proteins and a publicly-available database

HUPO initiated the Plasma Proteome Project (PPP) in 2002. Its pilot phase has (1) evaluated advantages and limitations of many depletion, fractionation, and MS technology platforms; (2) compared PPP reference specimens of human serum and EDTA, heparin, and citrate-anti-coagulated plasma; and (3) created a publicly-available knowledge base (www.bioinformatics.med.umich.edu/hupo/ppp; www.ebi.ac.uk/pride). Thirty-five participating laboratories in 13 countries submitted datasets. Working groups addressed (a) specimen stability and protein concentrations; (b) protein identifications from 18 MS/MS datasets; (c) independent analyses from raw MS-MS spectra; (d) search engine performance, subproteome analyses, and biological insights; (e) antibody arrays; and (f) direct MS/SELDI analyses. MS-MS datasets had 15 710 different International Protein Index (IPI) protein IDs; our integration algorithm applied to multiple matches of peptide sequences yielded 9504 IPI proteins identified with one or more peptides and 3020 proteins identified with two or more peptides (the Core Dataset). These proteins have been characterized with Gene Ontology, InterPro, Novartis Atlas, OMIM, and immunoassay-based concentration determinations. The database permits examination of many other subsets, such as 1274 proteins identified with three or more peptides. Reverse protein to DNA matching identified proteins for 118 previously unidentified ORFs. We recommend use of plasma instead of serum, with EDTA (or citrate) for anticoagulation. To improve resolution, sensitivity and reproducibility of peptide identifications and protein matches, we recommend combinations of depletion, fractionation, and MS/MS technologies, with explicit criteria for evaluation of spectra, use of search algorithms, and integration of homologous protein matches. This Special Issue of PROTEOMICS presents papers integral to the collaborative analysis plus many reports of supplementary work on various aspects of the PPP workplan. These PPP results on complexity, dynamic range, incomplete sampling, false-positive matches, and integration of diverse datasets for plasma and serum proteins lay a foundation for development and validation of circulating protein biomarkers in health and disease.