Who Needs Bereavement Support? A Population Based Survey of Bereavement Risk and Support Need

This study identifies and describes the profiles of bereavement risk and support needs of a community sample in Australia and tests the fit of the data with the three-tiered public health model for bereavement support. Family members who were bereaved 6–24 months prior to the survey and who were clients of four funeral providers participated (May-July 2013). A postal survey was used to collect information about bereaved people’s experience of caring and perceived satisfaction with any bereavement support provided. The questionnaire included a validated risk assessment screening measure for Prolonged Grief Disorder (PG-13). A total of 678 bereaved people responded. The model predicted that 60% of the sample would be low risk, 30% moderate risk, and 10% high risk. Actual figures were very close at 58.4%, 35.2% and 6.4% respectively. The analysis of the demographic characteristics, experience and impact of caring and bereavement, and satisfaction with support received from a variety of sources revealed differential experiences and needs that align with the expectation of low, moderate, and high bereavement support need, as articulated in the public health model. This is the first empirical test of the public health model of bereavement support. As there is a lack of clear evidence to guide development and allocation of bereavement support programs, the findings have the potential to inform the ability of services, community organizations and informal networks to prioritize care according to each level of bereavement need. This is essential to achieve cost-effective and equitable resource allocation.     

Weighted Score Tests Implementing Model-Averaging Schemes in Detection of Rare Variants in Case-Control Studies

Multi-locus effect modeling is a powerful approach for detection of genes influencing a complex disease. Especially for rare variants, we need to analyze multiple variants together to achieve adequate power for detection. In this paper, we propose several parsimonious branching model techniques to assess the joint effect of a group of rare variants in a case-control study. These models implement a data reduction strategy within a likelihood framework and use a weighted score test to assess the statistical significance of the effect of the group of variants on the disease. The primary advantage of the proposed approach is that it performs model-averaging over a substantially smaller set of models supported by the data and thus gains power to detect multi-locus effects. We illustrate these proposed approaches on simulated and real data and study their performance compared to several existing rare variant detection approaches. The primary goal of this paper is to assess if there is any gain in power to detect association by averaging over a number of models instead of selecting the best model. Extensive simulations and real data application demonstrate the advantage the proposed approach in presence of causal variants with opposite directional effects along with a moderate number of null variants in linkage disequilibrium.     

The Unfolding MD Simulations of Cyclophilin: Analyzed by Surface Contact Networks and Their Associated Metrics

Currently, considerable interest exists with regard to the dissociation of close packed aminoacids within proteins, in the course of unfolding, which could result in either wet or dry moltenglobules. The progressive disjuncture of residues constituting the hydrophobic core ofcyclophilin from L. donovani (LdCyp) has been studied during the thermal unfolding of the molecule, by molecular dynamics simulations. LdCyp has been represented as a surface contactnetwork (SCN) based on the surface complementarity (S_m) of interacting residues within themolecular interior. The application of S_m to side chain packing within proteins make it a very sensitive indicator of subtle perturbations in packing, in the thermal unfolding of the protein. Network based metrics have been defined to track the sequential changes in the disintegration ofthe SCN spanning the hydrophobic core of LdCyp and these metrics prove to be highly sensitive compared to traditional metrics in indicating the increased conformational (and dynamical) flexibility in the network. These metrics have been applied to suggest criteria distinguishing DMG, WMG and transition state ensembles and to identify key residues involved in crucial conformational/topological events during the unfolding process.     

Depletion of reduction potential and key energy generation metabolic enzymes underlies tellurite toxicity in Deinococcus radiodurans

Oxidative stress resistant Deinococcus radiodurans surprisingly exhibited moderate sensitivity to tellurite induced oxidative stress (LD₅₀ = 40 μM tellurite, 40 min exposure). The organism reduced 70% of 40 μM potassium tellurite within 5 h. Tellurite exposure significantly modulated cellular redox status. The level of ROS and protein carbonyl contents increased while the cellular reduction potential substantially decreased following tellurite exposure. Cellular thiols levels initially increased (within 30 min) of tellurite exposure but decreased at later time points. At proteome level, tellurite resistance proteins (TerB and TerD), tellurite reducing enzymes (pyruvate dehydrogense subunits E1 and E3), ROS detoxification enzymes (superoxide dismutase and thioredoxin reductase), and protein folding chaperones (DnaK, EF‐Ts, and PPIase) displayed increased abundance in tellurite‐stressed cells. However, remarkably decreased levels of key metabolic enzymes (aconitase, transketolase, 3‐hydroxy acyl‐CoA dehydrogenase, acyl‐CoA dehydrogenase, electron transfer flavoprotein alpha, and beta) involved in carbon and energy metabolism were observed upon tellurite stress. The results demonstrate that depletion of reduction potential in intensive tellurite reduction with impaired energy metabolism lead to tellurite toxicity in D. radiodurans.     

Releasable PEGylation of mesothelin targeted immunotoxin SS1P achieves single dosage complete regression of a human carcinoma in mice

Recombinant immunotoxins exhibit targeting and cytotoxic functions needed for cell-specific destruction. However, antitumor efficacy, safety, and pharmacokinetics of these therapeutics might be improved by further macromolecular engineering. SS1P is a recombinant anti-mesothelin immunotoxin in clinical trials in patients with mesothelin-expressing tumors. We have modified this immunotoxin using several PEGylation strategies employing releasable linkages between the protein and the PEG polymers, and observed superior performance of these bioconjugates when compared to similar PEG derivatives bearing permanent linkages to the polymers. PEGylated derivatives displayed markedly diminished cytotoxicity on cultured mesothelin-overexpressing A431-K5 cells; however, the releasable PEGylated immunotoxins exhibited increased antitumor activity in A431-K5 xenografts in mice, with a diminished animal toxicity. Most significantly, complete tumor regressions were achievable with single dose administration of the bioconjugates but not the native immunotoxin. Pharmacokinetic analysis of the releasable PEGylated derivatives in mice demonstrated an over 80-fold expansion of the area under the curve exposure of bioactive protein when compared to native immunotoxin. A correlation in degree of derivatization, release kinetics, and polymer size with potency was observed in vivo, whereas in vitro cytotoxicity was not predictive of efficacy in animal models. The potent antitumor efficacy of the releasable PEGylated mesothelin-targeted immunotoxins was not exhibited by similar untargeted PEG immunotoxins in this model. Since the bioconjugates can also exhibit the attributes of passive targeting via enhanced permeability and retention, this is the first demonstration of a pivotal role of active targeting for immunotoxin bioconjugate efficacy.     

Both cyclooxygenase- and cytokine-mediated inflammation are associated with carotid intima-media thickness

BACKGROUND: Common carotid artery intima-media thickness (CCA-IMT) is a valid index of atherosclerosis, which is viewed as an inflammatory disease. It is unknown if various modes of inflammation (cyclooxygenase [COX]-mediated, cytokine-mediated), oxidative stress and anti-oxidants are independently related to CCA-IMT. METHODS AND RESULTS: We investigated cross-sectional relations between CCA-IMT measured by B-mode ultrasound and COX-mediated inflammation (as measured by 15-keto-dihydro-prostaglandin F(2alpha) [PGF(2alpha)], cytokine-mediated inflammation (interleukin-6 [IL-6], high sensitivity C-reactive protein [hsCRP] and serum amyloid A protein [SAA]), oxidative stress (8-iso-PGF(2alpha), an F(2)-isoprostane; a non-enzymatic, free radical-induced product of arachidonic acid), and tocopherols (anti-oxidants) in a small subset of a population-based sample of elderly men (n=234) stating no use of anti-inflammatory medications. In a backward-stepwise regression analysis of correlates of CCA-IMT (with PGF(2alpha), hsCRP, IL-6, SAA, F(2)-isoprostanes, tocopherols, diabetes, body mass index (BMI), beta-blocker, statin treatment, smoking, hypertension and cholesterol), PGF(2alpha), CRP, beta-blocker treatment, diabetes and BMI were independently associated with CCA-IMT. There were no associations between F(2)-isoprostanes or tocopherols and CCA-IMT in this study. CONCLUSION: This study suggests both COX- and cytokine-mediated inflammation to be independently associated with increased CCA-IMT, implying that there might be more than one mode of inflammation involved in atherogenesis.     

Regulation of the formin for3p by cdc42p and bud6p

Formins are conserved actin nucleators responsible for the assembly of diverse actin structures. Many formins are controlled through an autoinhibitory mechanism involving the interaction of a C-terminal DAD sequence with an N-terminal DID sequence. Here, we show that the fission yeast formin for3p, which mediates actin cable assembly and polarized cell growth, is regulated by a similar autoinhibitory mechanism in vivo. Multiple sites govern for3p localization to cell tips. The localization and activity of for3p are inhibited by an intramolecular interaction of divergent DAD and DID-like sequences. A for3p DAD mutant expressed at endogenous levels produces more robust actin cables, which appear to have normal organization and dynamics. We identify cdc42p as the primary Rho GTPase involved in actin cable assembly and for3p regulation. Both cdc42p, which binds at the N terminus of for3p, and bud6p, which binds near the C-terminal DAD-like sequence, are needed for for3p localization and full activity, but a mutation in the for3p DAD restores for3p localization and other phenotypes of cdc42 and bud6 mutants. In particular, the for3p DAD mutation suppresses the bipolar growth (NETO) defect of bud6Delta cells. These findings suggest that cdc42p and bud6p activate for3p by relieving autoinhibition.     

Catechin as an antioxidant in liver mitochondrial toxicity: Inhibition of tamoxifen-induced protein oxidation and lipid peroxidation

Tamoxifen (TAM) is a nonsteroidal triphenylethylene antiestrogenic drug widely used in the treatment and prevention of breast cancer. TAM brings about a collapse of the mitochondrial membrane potential. It acts both as an uncoupling agent and as a powerful inhibitor of mitochondrial electron transport chain. The effect of catechin pretreatment on the mitochondrial toxicity of TAM was studied in liver mitochondria of Swiss albino mice. TAM treatment caused a significant increase in the mitochondrial lipid peroxidation (LPO) and the protein carbonyls (PCs). It also caused a significant increase in superoxide radical production. Pretreatment of mice with catechin (40 mg/kg) showed significant protection as demonstrated by marked attenuation of increased oxidative stress parameters such LPO, PCs, and superoxide production. It also restored the decreased nonenzymatic and enzymatic antioxidants of mitochondria. The inhibitory effect of catechin on TAM-:induced oxidative damage suggests that it may have potential benefits in prevention of human diseases where reactive oxygen species have some role as causative agents.