Wwox Binding to the Murine Brca1-BRCT Domain Regulates Timing of Brip1 and CtIP Phospho-Protein Interactions with This Domain at DNA Double-Strand Breaks,and Repair Pathway Choice

Wwox-deficient human cells show elevated homologous recombination, leading to resistance to killing by double-strand break-inducing agents. Human Wwox binds to the Brca1 981-PPLF-984 Wwox-binding motif, likely blocking the pChk2 phosphorylation site at Brca1-S988. This phosphorylation site is conserved across mammalian species; the PPLF motif is conserved in primates but not in rodents. We now show that murine Wwox does not bind Brca1 near the conserved mouse Brca1 phospho-S971 site, leaving it open for Chk2 phosphorylation and Brca1 activation. Instead, murine Wwox binds to Brca1 through its BRCT domain, where pAbraxas, pBrip1, and pCtIP, of the A, B, and C binding complexes, interact to regulate double-strand break repair pathway response. In Wwox-deficient mouse cells, the Brca1-BRCT domain is thus accessible for immediate binding of these phospho-proteins. We confirm elevated homologous recombination in Wwox-silenced murine cells, as in human cells. Wwox-deficient murine cells showed increased ionizing radiation-induced Abraxas, Brca1, and CtIP foci and long resected single-strand DNA, early after ionizing radiation. Wwox deletion increased the basal level of Brca1-CtIP interaction and the expression level of the MRN-CtIP protein complex, key players in end-resection, and facilitated Brca1 release from foci. Inhibition of phospho-Chk2 phosphorylation of Brca1-S971 delays the end-resection; the delay of premature end-resection by combining Chk2 inhibition with ionizing radiation or carboplatin treatment restored ionizing radiation and platinum sensitivity in Wwox-deficient murine cells, as in human cells, supporting the use of murine in vitro and in vivo models in preclinical cancer treatment research.     

Psychosocial considerations for mass decontamination

Mass exposure to explosions, infectious agents, foodborne illnesses, chemicals or radiological materials may require mass decontamination that have critical psychosocial implications for the public and for both traditional and non-traditional responders in terms of impact and of response. Five main issues are common to mass decontamination events: (i) perception, (ii) somatisation, (iii) media role and communication, (iv) information sharing, (v) behavioural guidance and (vi) organisational issues. Empirical evidence is drawn from a number of cases, including Chernobyl; Goiania, Brazil; the sarin gas attack in Tokyo; the anthrax attacks in the USA; Three Mile Island; and by features of the 2003 severe acute respiratory syndrome pandemic. In this paper, a common platform for mass casualty management is explored and suggestions for mass interventions are proposed across the complete event timeline, from pre-event threat and warning stages through to the impact and reconstruction phases. Implication for responders, healthcare and emergency infrastructure, public behaviour, screening processes, risk communication and media management are described.     

A20 Attenuates the Fibrotic Response in the Trabecular Meshwork

Although the extracellular matrix (ECM) in trabecular meshwork (TM) cells is known to be important in intraocular pressure (IOP) regulation, the molecular mechanisms involved in generating a glaucomatous environment in the TM are not completely understood. Recently we identified a molecular pathway, transforming growth factor beta 2 (TGFβ2)–toll-like receptor 4 (TLR4) signaling crosstalk, as an important regulator of glaucomatous damage in the TM, which contributes to fibrosis. Here we evaluate a novel molecular target, A20, also known as tumor necrosis factor alpha-induced protein 3 (TNFAIP3), which may help to block pathological TGFβ2–TLR4 signaling. Primary human TM cells were analyzed for A20 message and for A20 and fibronectin protein expression after treatment with TGFβ2. A20 message increased when the TLR4 pathway was inhibited in TM cells. In addition, TGFβ2, a known inducer of fibrosis, increased fibronectin expression, while at the same time decreasing the expression of A20. We then overexpressed A20 in TM cells in order to test the effect on treatment with TGFβ2, lipopolysaccharide (LPS), or cellular fibronectin extra domain A (cFN-EDA). Importantly, overexpression of A20 rescued the fibrotic response when TM cells were treated with TGFβ2, LPS, or cFN-EDA. In situ hybridization was used to probe for A20 RNA expression in age-matched control (C57BL/6J) mice and mice that constitutively express the EDA isoform of fibronectin (B6.EDA^+/+). In this novel mouse model of glaucoma, A20 RNA was increased versus age-matched control mice in a cyclic manner at 6 weeks and 1 year of age, but not at 8 months. Overall, these data suggest that A20 may work through a negative feedback mechanism attenuating the ability of TGFβ2–TLR4 signaling to induce fibrosis.     

Juvenile drug court: Enhancing outcomes by integrating evidence-based treatments.

Evaluated the effectiveness of juvenile drug court for 161 juvenile offenders meeting diagnostic criteria for substance abuse or dependence and determined whether the integration of evidence-based practices enhanced the outcomes of juvenile drug court. Over a 1-year period, a four-condition randomized design evaluated outcomes for family court with usual community services, drug court with usual community services, drug court with multisystemic therapy, and drug court with multisystemic therapy enhanced with contingency management for adolescent substance use, criminal behavior, symptomatology, and days in out-of-home placement. In general, findings supported the view that drug court was more effective than family court services in decreasing rates of adolescent substance use and criminal behavior. Possibly due to the greatly increased surveillance of youths in drug court, however, these relative reductions in antisocial behavior did not translate to corresponding decreases in rearrest or incarceration. In addition, findings supported the view that the use of evidence-based treatments within the drug court context improved youth substance-related outcomes. Clinical and policy implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of a light timber‐framed compartment in natural fire subjected to lateral load

A common approach for designing buildings for lateral stability during and post‐fire in New Zealand is to ensure that a fire‐rated structure does not collapse when subjected to a nominal horizontal force. For external walls of residential buildings, which are required to resist a lateral load of 0.5 kPa, it is hypothesised that the adjacent unrated construction could provide sufficient support. A natural fire experiment has been conducted to evaluate the fire performance of a laterally loaded light timber‐framed compartment, with external dimensions of 4.33 m × 3.35 m and a stud height of 2.4 m constructed with a timber truss roof and plasterboard ceiling. During the experiment, the ceiling collapsed at 12 to 13 minutes, and the bottom chord of the roof truss failed in tension after 28 minutes which resulted in the fire‐rated wall losing its lateral stability at 28 minutes. The fire severity experienced in the compartment has been estimated to correspond to an equivalent time of 33‐minute exposure to a standard furnace time‐temperature. It is concluded that there is no need to provide nominal (additional) moment‐resisting fixity at the base of the fire‐rated wall when exposed to the standard fire for no more than 30 minutes.     

Decoding the Molecular Effects of Atovaquone Linked Resistant Mutations on Plasmodium falciparum Cytb-ISP Complex in the Phospholipid Bilayer Membrane

Atovaquone (ATQ) is a drug used to prevent and treat malaria that functions by targeting the Plasmodium falciparum cytochrome b (PfCytb) protein. PfCytb catalyzes the transmembrane electron transfer (ET) pathway which maintains the mitochondrial membrane potential. The ubiquinol substrate binding site of the protein has heme bL, heme bH and iron-sulphur [2FE-2S] cluster cofactors that act as redox centers to aid in ET. Recent studies investigating ATQ resistance mechanisms have shown that point mutations of PfCytb confer resistance. Thus, understanding the resistance mechanisms at the molecular level via computational approaches incorporating phospholipid bilayer would help in the design of new efficacious drugs that are also capable of bypassing parasite resistance. With this knowledge gap, this article seeks to explore the effect of three drug resistant mutations Y268C, Y268N and Y268S on the PfCytb structure and function in the presence and absence of ATQ. To draw reliable conclusions, 350 ns all-atom membrane (POPC:POPE phospholipid bilayer) molecular dynamics (MD) simulations with derived metal parameters for the holo and ATQ-bound -proteins were performed. Thereafter, simulation outputs were analyzed using dynamic residue network (DRN) analysis. Across the triplicate MD runs, hydrophobic interactions, reported to be crucial in protein function were assessed. In both, the presence and absence of ATQ and a loss of key active site residue interactions were observed as a result of mutations. These active site residues included: Met 133, Trp136, Val140, Thr142, Ile258, Val259, Pro260 and Phe264. These changes to residue interactions are likely to destabilize the overall intra-protein residue communication network where the proteins’ function could be implicated. Protein dynamics of the ATQ-bound mutant complexes showed that they assumed a different pose to the wild-type, resulting in diminished residue interactions in the mutant proteins. In summary, this study presents insights on the possible effect of the mutations on ATQ drug activity causing resistance and describes accurate MD simulations in the presence of the lipid bilayer prior to conducting inhibitory drug discovery for the PfCytb-iron sulphur protein (Cytb-ISP) complex.     

Use of manure nutrients from concentrated animal feeding operations

Over the past few decades, there has been a nationwide trend away from small livestock farms and toward large Concentrated Animal Feeding Operations (CAFOs). This shift results in concentrated manure production and introduces potential problems associated with its disposal. We analyzed data from 13 permitted CAFOs in southeastern Michigan, including 1187 occurrences of manure application from 12 of the CAFOs with available field-level data. CAFOs applied excess manure nutrients to cropland by applying to fields with soil phosphorus test levels >50?ppm (42% of all cases), applying to soybeans (7% of all cases), over-estimating crop yields in calculating plant nutrient requirements (67% of all cases), and applying beyond what is allowed by state permits (26% of all cases). This represents significant potential for redistribution of manure nutrients. The total amount of manure from all instances of over-application could be redistributed to fertilize over 4775?ha (11,800?acres) per year. Significant barriers to redistribution of manure exist, however, including cost, land availability, crop and soil need, transport logistics, and farmers' reluctance to use manure instead of inorganic fertilizer due to its variable composition. These findings are relevant to the harmful algal bloom and hypoxia issues in Lake Erie, which are driven by excess nutrients, and can be used to better inform science, modeling, and policy in the region.     

A review of methods for determining structural fire severity—Part I: A historical perspective

There is a risk of a building suffering unsustainable structural damage in the event of a large fire. Therefore, it is necessary to design buildings to withstand expected fires. A widely used simplified calculation method is the so-called ‘time-equivalence’ method. There are significant concerns about the suitability of this method. This paper is Part I of a twofold study examining the state of the art of time-equivalence methods. The purpose of this paper is to provide a detailed background of the development of time-equivalence methods since its first introduction in 1928 and to provide an initial high-level assessment of the accuracy of these methods. A simple scoring system is used to assess the methods based on the accuracy of the analysis techniques used in their derivation. The study revealed that most methods do not account well for structural system response to fire exposure. While some time-equivalence methods do yield accurate results, further analysis is required to fully assess their suitability.