Influence of association state and DNA binding on the O2-reactivity of [4Fe-4S] fumarate and nitrate reduction (FNR) regulator

The fumarate and nitrate reduction (FNR) regulator is the master switch for the transition between anaerobic and aerobic respiration in Escherichia coli. Reaction of dimeric [4Fe-4S] FNR with O2 results in conversion of the cluster into a [2Fe-2S] form, via a [3Fe-4S] intermediate, leading to the loss of DNA binding through dissociation of the dimer into monomers. In the present paper, we report studies of two previously identified variants of FNR, D154A and I151A, in which the form of the cluster is decoupled from the association state. In vivo studies of permanently dimeric D154A FNR show that DNA binding does not affect the rate of cluster incorporation into the apoprotein or the rate of O2-mediated cluster loss. In vitro studies show that O2-mediated cluster conversion for D154A and the permanent monomer I151A FNR is the same as in wild-type FNR, but with altered kinetics. Decoupling leads to an increase in the rate of the [3Fe-4S]1+ into [2Fe-2S]2+ conversion step, consistent with the suggestion that this step drives association state changes in the wild-type protein. We have also shown that DNA-bound FNR reacts more rapidly with O2 than FNR free in solution, implying that transcriptionally active FNR is the preferred target for reaction with O2

Effect of post-pyloric Dobhoff tube retention during gastrojejunostomy for reduction of fluoroscopic time and radiation dose

The purpose of this study was to determine whether retention of a post-pyloric Dobhoff tube (DHT) in position to serve as a visual guide through the pylorus during gastrojejunostomy (GJ) tube placement results in a reduction in fluoroscopy time, procedure time, and estimated radiation dose. A retrospective study evaluated patients who underwent GJ tube placement or gastric to GJ conversion from January 1, 2017, to April 1, 2021. Demographic and procedural data were collected, and results were evaluated using descriptive statistics and hypothesis testing through an unpaired Student’s t-test. Of the 71 GJ tube placements included for analysis, 12 patients underwent placement with a post-pyloric DHT in position, and 59 patients underwent placement without a post-pyloric DHT in position. The mean fluoroscopy time and estimated radiation dose were significantly reduced in patients who underwent GJ tube placement with a post-pyloric DHT in position compared with those without (7.08 min vs. 11.02 min, P = 0.004; 123.12 mGy vs. 255.19 mGy, P = 0.015, respectively). The mean total procedure time was also reduced in patients who underwent GJ tube placement with a post-pyloric DHT in position compared with those who had no post-pyloric DHT, but this finding lacked statistical significance (18.55 min vs. 23.15 min; P = 0.09). Post-pyloric DHT retention can be utilized during GJ tube placement to reduce radiation exposure to both the patient and interventionalist

Characteristics and Predictors of Intensive Care Unit Admission in Pediatric Blunt Abdominal Trauma

BACKGROUND: Pediatric trauma patients sustaining blunt abdominal trauma (BAT) with intra-abdominal injury (IAI) are frequently admitted to the intensive care unit (ICU). This study was performed to identify predictors for ICU admission following BAT. METHODS: Prospective study of children (\u3c 16 years) who presented to 14 Level-One Pediatric Trauma Centers following BAT over a 1-year period. Patients were categorized as ICU or non-ICU patients. Data collected included vitals, physical exam findings, laboratory results, imaging, and traumatic injuries. A multivariable hierarchical logistic regression model was used to identify predictors of ICU admission. Predictive ability of the model was assessed via tenfold cross-validated area under the receiver operating characteristic curves (cvAUC). RESULTS: Included were 2,182 children with 21% (n = 463) admitted to the ICU. On univariate analysis, ICU patients were associated with abnormal age-adjusted shock index, increased injury severity scores (ISS), lower Glasgow coma scores (GCS), traumatic brain injury (TBI), and severe solid organ injury (SOI). With multivariable logistic regression, factors associated with ICU admission were severe trauma (ISS \u3e 15), anemia (hematocrit \u3c 30), severe TBI (GCS \u3c 8), cervical spine injury, skull fracture, and severe solid organ injury. The cvAUC for the multivariable model was 0.91 (95% CI 0.88-0.92). CONCLUSION: Severe solid organ injury and traumatic brain injury, in association with multisystem trauma, appear to drive ICU admission in pediatric patients with BAT. These results may inform the design of a trauma bay prediction rule to assist in optimizing ICU resource utilization after BAT. STUDY DESIGN: Prognosis study

Coibamide A Targets Sec61 to Prevent Biogenesis of Secretory and Membrane Proteins

Coibamide A (CbA) is a marine natural product with potent antiproliferative activity against human cancer cells and a unique selectivity profile. Despite promising antitumor activity, the mechanism of cytotoxicity and specific cellular target of CbA remain unknown. Here, we develop an optimized synthetic CbA photoaffinity probe (photo-CbA) and use it to demonstrate that CbA directly targets the Sec61 alpha subunit of the Sec61 protein translocon. CbA binding to Sec61 results in broad substratenonselective inhibition of ER protein import and potent cytotoxicity against specific cancer cell lines. CbA targets a lumenal cavity of Sec61 that is partially shared with known Sec61 inhibitors, yet profiling against resistance conferring Sec61 alpha mutations identified from human HCT116 cells su ests a distinct binding mode for CbA. Specifically, despite conferring strong resistance to all previously known Sec61 inhibitors, the Sec61 alpha mutant R66I remains sensitive to CbA. A further unbiased screen for Sec61 alpha resistance mutations identified the CbA-resistant mutation S71P, which confirms nonidentical binding sites for CbA and apratoxin A and supports the susceptibility of the Sec61 plug region for channel inhibition. Remarkably, CbA, apratoxin A, and ipomoeassin F do not display comparable patterns of potency and selectivity in the NCI60 panel of human cancer cell lines. Our work connecting CbA activity with selective prevention of secretory and membrane protein biogenesis by inhibition of Sec61 opens up possibilities for developing new Sec61 inhibitors with improved druglike properties that are based on the coibamide pharmacophore.Peer reviewe

First-in-Class Mitogen-Activated Protein Kinase p38α: MAPK-Activated Protein Kinase-2 (MK2) Dual Signal Modulator with Anti-inflammatory and Endothelial-stabilizing Properties.

We previously identified a small molecule, UM101, predicted to bind to the substrate-binding groove of p38aMitogen-activated Protein Kinase (MAPK) near the binding site of its proinflammatory substrate, MAPK-activated protein kinase (MK2). UM101 exhibited anti-inflammatory, endothelial-stabilizing, and lung-protective effects. To overcome its limited aqueous solubility and p38a binding affinity, we designed an analog of UM101, GEn-1124, with improved aqueous solubility, stability, and p38a binding affinity. Compared with UM101, GEn-1124 has 18-fold greater p38a-binding affinity as measured by Surface Plasmon Resonance (SPR), 11-fold greater aqueous solubility, enhanced barrier-stabilizing activity in thrombin-stimulated human pulmonary artery endothelial cells (hPAEC) in vitro, and greater lung protection in vivo GEn-1124 improved survival from 10% to 40% in murine acute lung injury (ALI) induced by combined exposure to intratracheal bacterial endotoxin lipopolysaccharide (LPS) instillation and febrile-range hyperthermia (FRH) and from 0% to 50% in a mouse influenza pneumonia model. Gene expression analysis by RNASeq in TNFa-treated hPAEC showed that the gene-modifying effects of GEn-1124 were much more restricted to TNFa-inducible genes than the catalytic site p38 inhibitor, SB203580. Gene expression pathway analysis, confocal immunofluorescence analysis of p38aand MK2 subcellular trafficking, and SPR analysis of phosphorylated p38a:MK2 binding affinity supports a novel mechanism of action. GEn-1124 destabilizes the activated p38a:MK2 complex, dissociates nuclear export of MK2 and p38a, thereby promoting intranuclear retention and enhanced intranuclear signaling by phosphorylated p38a retention, and accelerated inactivation of p38-free cytosolic MK2 by unopposed phosphatases. Significance Statement We describe an analog of our first-in-class small molecule modulator of p38a/MK2 signaling targeted to a pocket near the ED substrate binding domain of p38a, which destabilizes the p38a:MK2 complex without blocking p38 catalytic activity or ablating downstream signaling. The result is a rebalancing of downstream pro- and anti-inflammatory signaling, yielding anti-inflammatory, endothelial-stabilizing, and lung-protective effects with therapeutic potential in ARDS

How to measure working memory capacity in the change detection paradigm

Although the measurement of working memory capacity is crucial to understanding working memory and its interaction with other cognitive faculties, there are inconsistencies in the literature on how to measure capacity. We address the measurement in the change detection paradigm, popularized by Luck and Vogel (Nature, 390, 279–281, 1997). Two measures for this task—from Pashler (Perception & Psychophysics, 44, 369–378, 1988) and Cowan (The Behavioral and Brain Sciences, 24, 87–114, 2001), respectively—have been used interchangeably, even though they may yield qualitatively different conclusions. We show that the choice between these two measures is not arbitrary. Although they are motivated by the same underlying discrete-slots working memory model, each is applicable only to a specific task; the two are never interchangeable. In the course of deriving these measures, we discuss subtle but consequential flaws in the underlying discrete-slots model. These flaws motivate revision in the modal model and capacity measures

Carbohydrate antigens in nipple aspirate fluid predict the presence of atypia and cancer in women requiring diagnostic breast biopsy

<p>Abstract</p> <p>Background</p> <p>The goal of this prospective study was to determine (a) concentrations of the carbohydrate biomarkers Thomsen Friedenreich (TF) antigen and its precursor, Tn antigen, in nipple discharge (ND) collected from women requiring biopsy because of a suspicious breast lesion; and (b) if concentration levels predicted pathologic diagnosis.</p> <p>Methods</p> <p>Adult women requiring biopsy to exclude breast cancer were enrolled and ND obtained. The samples from 124 women were analyzed using an anti-TF and anti-Tn monoclonal antibodies in direct immunoassay.</p> <p>Results</p> <p>The highest median concentration in ND for TF and Tn was in women with ductal carcinoma <it>in situ </it>(DCIS). TF was higher in women with 1) cancer (DCIS or invasive) vs. either no cancer (atypia or benign pathology, p = .048), or benign pathology (p = .018); and 2) abnormal (atypia or cancer) versus benign pathology (p = .016); and was more predictive of atypia or cancer in post- compared to premenopausal women. Tn was not predictive of disease. High TF concentration and age were independent predictors of disease, correctly classifying either cancer or abnormal vs. benign pathology 83% of the time in postmenopausal women.</p> <p>Conclusions</p> <p>TF concentrations in ND were higher in women with precancer and cancer compared to women with benign disease, and TF was an independent predictor of breast atypia and cancer. TF may prove useful in early breast cancer detection.</p

Медицинские и социальные аспекты коммерческого секса

Представлены демографические, медицинские, психологические и социальные характеристики женщин, оказывающих платные сексуальные услуги. Обсуждается проблема легализации и регламентации проституции в контексте профилактики инфекций, передающихся половым путем, и заражения ВИЧ.Demographic, medical, psychological and social characteristics of women rendering sexual services are described. The problem of legalization and regulation of prostitution in the context of prevention of sexually transmitted infections and HIV is discussed

Advances in GPCR modeling evaluated by the GPCR Dock 2013 assessment: Meeting new challenges

© 2014 Elsevier Ltd All rights reserved. Despite tremendous successes of GPCR crystallography, the receptors with available structures represent only a small fraction of human GPCRs. An important role of the modeling community is to maximize structural insights for the remaining receptors and complexes. The community-wide GPCR Dock assessment was established to stimulate and monitor the progress in molecular modeling and ligand docking for GPCRs. The four targets in the present third assessment round presented new and diverse challenges for modelers, including prediction of allosteric ligand interaction and activation states in 5-hydroxytryptamine receptors 1B and 2B, and modeling by extremely distant homology for smoothened receptor. Forty-four modeling groups participated in the assessment. State-of-the-art modeling approaches achieved close-to-experimental accuracy for small rigid orthosteric ligands and models built by close homology, and they correctly predicted protein fold for distant homology targets. Predictions of long loops and GPCR activation states remain unsolved problems