bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of Many Charged Residues at the Stator-Rotor Interface of the Na
+
-Driven Flagellar Motor to Torque Generation in Vibrio alginolyticus
Authors: Takekawa Norihiro , Kojima Seiji , Homma Michio 
Published: January 2014

ABSTRACT

In torque generation by the bacterial flagellar motor, it has been suggested that electrostatic interactions between charged residues of MotA and FliG at the rotor-stator interface are important. However, the actual role(s) of those charged residues has not yet been clarified. In this study, we systematically made mutants of
Vibrio alginolyticus
whose charged residues of PomA (MotA homologue) and FliG were replaced by uncharged or charge-reversed residues and characterized the motilities of those mutants. We found that the members of a group of charged residues, 7 in PomA and 6 in FliG, collectively participate in torque generation of the Na
+
-driven flagellar motor in
Vibrio
. An additional specific interaction between PomA-E97 and FliG-K284 is critical for proper performance of the
Vibrio
motor. Our results also reveal that more charged residues are involved in the PomA-FliG interactions in the
Vibrio
Na
+
-driven motor than in the MotA-FliG interactions in the H
+
-driven one. This suggests that a larger number of conserved charged residues at the PomA-FliG interface contributes to the robustness of the
Vibrio
motor against mutations. The interaction surfaces of the stator and rotor of the Na
+
-driven motor seem to be more complex than those previously proposed in the H
+
-driven motor.
Nonclassical Transpeptidases of Mycobacterium tuberculosis Alter Cell Size, Morphology, the Cytosolic Matrix, Protein Localization, Virulence, and Resistance to β-Lactams
Authors: Schoonmaker Maia K. , Bishai William R. , Lamichhane Gyanu 
Published: January 2014

ABSTRACT

Virtually all bacteria possess a peptidoglycan layer that is essential for their growth and survival. The β-lactams, the most widely used class of antibiotics in human history, inhibit
d,d
-transpeptidases, which catalyze the final step in peptidoglycan biosynthesis. The existence of a second class of transpeptidases, the
l,d
-transpeptidases, was recently reported.
Mycobacterium tuberculosis
, an infectious pathogen that causes tuberculosis (TB), is known to possess as many as five proteins with
l,d
-transpeptidase activity. Here, for the first time, we demonstrate that loss of
l,d
-transpeptidases 1 and 2 of
M. tuberculosis
(Ldt
Mt1
and Ldt
Mt2
) alters cell surface morphology, shape, size, organization of the intracellular matrix, sorting of some low-molecular-weight proteins that are targeted to the membrane or secreted, cellular physiology, growth, virulence, and resistance of
M. tuberculosis
to amoxicillin-clavulanate and vancomycin.
Global Analysis of the Burkholderia thailandensis Quorum Sensing-Controlled Regulon
Authors: Majerczyk Charlotte , Brittnacher Mitchell , Jacobs Michael , Armour Christopher D. , Radey Mathew , Schneider Emily , Phattarasokul Somsak , Bunt Richard , Greenberg E. Peter 
Published: January 2014

ABSTRACT

Burkholderia thailandensis
contains three acyl-homoserine lactone quorum sensing circuits and has two additional LuxR homologs. To identify
B. thailandensis
quorum sensing-controlled genes, we carried out transcriptome sequencing (RNA-seq) analyses of quorum sensing mutants and their parent. The analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. We also found that genes coding for contact-dependent inhibition were induced by quorum sensing and confirmed that specific quorum sensing mutants had a contact-dependent inhibition defect. Additional quorum-controlled genes included those for the production of numerous secondary metabolites, an uncharacterized exopolysaccharide, and a predicted chitin-binding protein. This study provides insights into the roles of the three quorum sensing circuits in the saprophytic lifestyle of
B. thailandensis
, and it provides a foundation on which to build an understanding of the roles of quorum sensing in the biology of
B. thailandensis
and the closely related pathogenic
Burkholderia pseudomallei
and
Burkholderia mallei
.
Influence of O Polysaccharides on Biofilm Development and Outer Membrane Vesicle Biogenesis in Pseudomonas aeruginosa PAO1
Authors: Murphy Kathleen , Park Amber J. , Hao Youai , Brewer Dyanne , Lam Joseph S. , Khursigara Cezar M. 
Published: January 2014

ABSTRACT

Pseudomonas aeruginosa
is a common opportunistic human pathogen known for its ability to adapt to changes in its environment during the course of infection. These adaptations include changes in the expression of cell surface lipopolysaccharide (LPS), biofilm development, and the production of a protective extracellular exopolysaccharide matrix. Outer membrane vesicles (OMVs) have been identified as an important component of the extracellular matrix of
P. aeruginosa
biofilms and are thought to contribute to the development and fitness of these bacterial communities. The goal of this study was to examine the relationships between changes in the cell surface expression of LPS O polysaccharides, biofilm development, and OMV biogenesis in
P. aeruginosa
. We compared wild-type
P. aeruginosa
PAO1 with three chromosomal knockouts. These knockouts have deletions in the
rmd
,
wbpM
, and
wbpL
genes that produce changes in the expression of common polysaccharide antigen (CPA), O-specific antigen (OSA), or both. Our results demonstrate that changes in O polysaccharide expression do not significantly influence OMV production but do affect the size and protein content of OMVs derived from both CPA
−
and OSA
−
cells; these mutant cells also exhibited different physical properties from wild-type cells. We further examined biofilm growth of the mutants and determined that CPA
−
cells could not develop into robust biofilms and exhibit changes in cell morphology and biofilm matrix production. Together these results demonstrate the importance of O polysaccharide expression on
P. aeruginosa
OMV composition and highlight the significance of CPA expression in biofilm development.
Disease status, patient quality of life and healthcare resource use for ulcerative colitis in the UK: an observational study
Authors: Vaizey Carolynne J , Gibson Peter R , Black Christopher M , Nicholls Rebecca J , Weston Adèle R , Gaya Daniel R , Sebastian Shaji , Shaw Ian , Lewis Stephen , Bloom Stuart , Gordon John N , Beale Amanda , Arnott Ian , Campbell Simon , Fan Tao 
Published: January 2014

BackgroundUlcerative colitis is a lifelong, chronic, relapsing-remitting disease.ObjectiveTo assess the relationship between ulcerative colitis disease status and patient quality of life, and to determine the impact of ulcerative colitis on healthcare costs and work productivity, in the UK.MethodsClinicians assessed 173 adult patients’ current disease status at a single study visit using the partial Mayo (pMayo) instrument. Patients completed the Euro Quality of Life 5-dimension, 5-level (EQ-5D-5L) questionnaire, the Work Productivity and Activity Impairment (WPAI) questionnaire. Healthcare resource use was determined from questionnaires and from patients’ medical charts.ResultsPatients in remission had a significantly higher EQ-5D-5L scores (mean (SD) 0.86 (0.15)) than patients with active disease (0.71 (0.20); p<0.001). Patients with mild disease had significantly higher mean (SD) EQ-5D-5L scores than patients with moderate/severe disease: 0.77 (0.11) and 0.66 (0.24), respectively (p<0.001). The mean percent productivity impairment was greater for patients with active disease than for patients in remission on all items of the WPAI questionnaire: 24.6% vs 1.8% for work time missed, 34.1% vs 12.9% for impairment while working, 40.8% vs 14.4% for overall work impairment and 42.7% vs 13.0% for activity impairment (p<0.001 for all comparisons). The mean (SD) total cost of healthcare for ulcerative colitis in the prior 3 months was £1211 (1588).ConclusionsWhen compared with patients in remission, patients with active ulcerative colitis have significantly worse quality of life and significantly more work impairment. The healthcare costs of ulcerative colitis are considerable.
Expression of EpCAMMFand EpCAMMTvariants in human carcinomas
Authors: Fong Dominic , Seeber Andreas , Terracciano Luigi , Kasal Armin , Mazzoleni Guido , Lehne Florian , Gastl Guenther , Spizzo Gilbert 
Published: January 2014

AimsRegulated intramembrane proteolysis has been shown to be an important mechanism for oncogenic activation of epithelial cell adhesion molecule (EpCAM) through nuclear translocation of the intracellular domain EpICD. Recent studies have identified new membrane-bound EpCAM variants. To evaluate the prevalence of two membranous EpCAM variants in human tumours, we performed a large-scale expression analysis using specific antibodies against the extracellular domain EpEX (MOC-31 clone) and the intracellular domain EpICD (9-2 clone) of the EpCAM antigen by immunohistochemistry.Material and methodsTwo multi-tissue microarrays (TMA) series containing 1564 tissue samples each of 53 different histological tumour types were stained and compared. One TMA was stained for EpEX and one for EpICD. Membranous full-length EpCAM (EpCAMMF) expression in tissues was defined by the expression of EpEX and EpICD, while the truncated variant of EpCAM (EpCAMMT) was characterised by a significant loss of membranous EpICD expression compared with EpEX expression.ResultsWe defined tumours with high EpCAMMTexpression (ie, cancers of the endometrium and bladder), tumours with intermediate (ie, gastric, pancreatic, colorectal and oesophageal cancer) and tumours with low rates of expression of the EpCAMMTvariant (ie, lung, ovarian, gallbladder, breast and prostate cancer).ConclusionsOur results indicate that loss of membranous EpICD expression is a common event in human epithelial carcinomas, arguing for the expression of different degrees of EpCAMMFand EpCAMMTvariants across the most important tumour entities. Future studies evaluating the prognostic and predictive role of these variants in human malignancies, especially in patients treated with EpCAM-specific antibodies, are clearly warranted.
Young men and the morning after: a missed opportunity for emergency contraception provision?
Authors: Schrager Sheree M , Olson Johanna , Beharry Meera , Belzer Marvin , Goldsich Katherine , Desai Mona , Clark Leslie F 
Published: January 2014

ObjectivesAlthough adolescents and young adults of lower socioeconomic status (SES) are disproportionately affected by unintended pregnancies, research on experiences with emergency contraception (EC) in this population has lagged. Furthermore, it is unclear whether EC-related knowledge and behaviour varies between young men and women. This study investigated knowledge, attitudes and experiences with EC among low SES young men and women aged 18–25 years.MethodsOne hundred and ninety-eight new enrollees at two Los Angeles primary medical care clinics completed surveys about their knowledge, past use and likelihood of using EC. Chi square (χ2) and regression analyses assessed gender differences in knowledge and attitudes.ResultsWomen were more likely than men to accurately answer questions about EC and its use. Across both sexes, accurate knowledge predicted future willingness to use EC. Only half the women and a third of men knew that EC could be directly dispensed by pharmacists; even fewer knew that the legal access age for EC was 17 years (13%) or that men could access EC from pharmacies for their female partners (24%). Although respondents most commonly reported that friends were their source of current information about EC, both men and women chose health care professionals as their desired source of future information about EC.ConclusionsYoung men in this sample were significantly less knowledgeable than young women about EC. Educating young men about EC by health care providers during routine visits may be a unique opportunity to increase EC knowledge, access and use among low-income young couples to decrease undesired pregnancies.
Contraceptive use among women presenting to pharmacies for emergency contraception: an opportunity for intervention
Authors: Michie Lucy , Cameron Sharon T , Glasier Anna , Greed Elizabeth 
Published: January 2014

ObjectivesMost women who use emergency contraception (EC) do so because of unprotected sexual intercourse or condom failure and so remain at risk of pregnancy unless they commence an effective method of contraception. In Great Britain, increasingly women now choose to obtain EC from a pharmacy; however, pharmacists do not currently provide effective ongoing contraception. We sought to determine the views of women obtaining EC from pharmacies and clinicians working in sexual and reproductive health care (SRH) about the possibility of pharmacists providing a temporary supply of a progestogen-only pill (POP) together with EC.MethodsSelf-administered, anonymous questionnaires of (1) women requesting EC from pharmacies in Edinburgh, Scotland and (2) SRH clinicians attending a major UK scientific meeting.ResultsA total of 211/232 women completed questionnaires in pharmacies (a 91% response rate). Of those women not using a hormonal method of contraception at the time of EC (n=166; 79%), almost half (44%) wished to use an effective method. Most women (64%) agreed that the option of a pharmacist being able to supply a POP would have been helpful. Among the SRH clinicians, 110 completed questionnaires out of 150 distributed (a 73% response rate). The majority of respondents (92%) were positive about a pharmacist supplying a POP at the time of EC.ConclusionsA reasonable proportion of women requesting EC would like to start using an effective contraceptive method. Both the women and the SRH clinicians we surveyed are positive about the option of a short supply of a POP being provided by the pharmacy in the UK together with EC.
Primary blast lung injury at a NATO Role 3 hospital
Authors: Aboudara Matthew , Mahoney P F , Hicks B , Cuadrado D 
Published: January 2014

BackgroundPrimary blast lung injury (PBLI) is defined as lung contusion from barotrauma following an explosive mechanism of injury (MOI). Military data have focused on PBLI characteristics following evacuation from the combat theatre; less is known about its immediate management and epidemiology in the deployed setting. We conducted a quality improvement project to describe the prevalence, clinical characteristics, management strategies and evacuation techniques for PBLI patients prior to evacuation.MethodsPatients admitted to a Role 3 hospital in southwest, Afghanistan, from January 2008 to March 2013 with a blast MOI were identified through the Department of Defense Trauma Registry; International Classification of Diseases 9 codes and patient record review were used to identify the PBLI cohort from radiology reports. Descriptive statistics and Fishers exact test were used to report findings.ResultsPrevalence of PBLI among blast injured patients with radiology reports was 11.2% (73/648). The population exhibited high Injury Severity Scores median 25 (IQR 14–34) and most received a massive blood transfusion (mean 33.4±38.3 total blood products/24 h). The mean positive end expiratory pressure (PEEP) requirement was 6.2±3.7 (range 5–15) cm H2O and PaO2to FiO2ratio was 297±175.2 (66–796) mm Hg. However, 16.6% of patients had a PaO2to FiO2ratio <200, 13.3% required PEEP ≥10 cm H2O and one patient required specialised evacuation for respiratory failure. A dismounted MOI (72.8%) and evacuation from point of injury by the Medical Emergency Response Team (62.3%) appeared to be associated with worse lung injury. Only eight of the 73 PBLI patients died and of the five with retrievable records, none died from respiratory failure.ConclusionsPBLI has a low prevalence and conventional lung protective ventilator management is generally appropriate immediately after injury; application of advanced modes of ventilation and specialised evacuation assistance may be required. PBLI may be a marker of underlying injury severity since all deaths were not due to respiratory failure. Further work is needed to determine exact MOI in mounted and dismounted casualties.
Translational research to improve the treatment of severe extremity injuries
Authors: Brown Kate V , Penn-Barwell J G , Rand B C , Wenke J C 
Published: January 2014

ObjectivesSevere extremity injuries are the most significant injury sustained in combat wounds. Despite optimal clinical management, non-union and infection remain common complications. In a concerted effort to dovetail research efforts, there has been a collaboration between the UK and USA, with British military surgeons conducting translational studies under the auspices of the US Institute of Surgical Research. This paper describes 3 years of work.MethodsA variety of studies were conducted using, and developing, a previously validated rat femur critical-sized defect model. Timing of surgical debridement and irrigation, different types of irrigants and different means of delivery of antibiotic and growth factors for infection control and to promote bone healing were investigated.ResultsEarly debridement and irrigation were independently shown to reduce infection. Normal saline was the most optimal irrigant, superior to disinfectant solutions. A biodegradable gel demonstrated superior antibiotic delivery capabilities than standard polymethylmethacrylate beads. A polyurethane scaffold was shown to have the ability to deliver both antibiotics and growth factors.DiscussionThe importance of early transit times to Role 3 capabilities for definitive surgical care has been underlined. Novel and superior methods of antibiotic and growth factor delivery, compared with current clinical standards of care, have been shown. There is the potential for translation to clinical studies to promote infection control and bone healing in these devastating injuries.
Contrast-enhanced time-resolved MRA for pre-angiographic evaluation of suspected spinal dural arterial venous fistulas
Authors: Saindane Amit M , Boddu Srikanth R , Tong Frank C , Dehkharghani Seena , Dion Jacques E 
Published: January 2014

BackgroundSpinal digital subtraction angiography (DSA) is the gold standard for diagnosis of spinal dural arterial venous fistulas (SDAVFs), but can require extensive time, radiation exposure and contrast dose. We hypothesize that contrast-enhanced time-resolved MR angiography (CE-TR MRA) will have utility for the non-invasive diagnosis and pre-angiographic localization of SDAVFs.MethodsEighteen patients underwent both CE-TR MRA and DSA for suspected SDAVFs, with DSA performed a median of 11 days (range 0–41) after MRA. CE-TR MRA was performed on a 1.5 T GE unit using Time Resolved Imaging of Contrast Kinetics (TRICKS). CE-TR MRA and DSA images were evaluated for the presence of SDAVFs and location of the feeding arterial supply, with DSA as the reference standard. DSA was also evaluated for the number of vessels catheterized, contrast volume and fluoroscopic and procedure times.ResultsEight of the 18 patients were positive for SDAVF on DSA. Sensitivity, specificity, positive predictive value and negative predictive value for the 18 CE-TR MRAs were 88%, 90%, 88% and 90%, respectively. Localization of the SDAVF arterial supply on CE-TR MRA was within one vertebral level from DSA for 6/7 SDAVFs. Compared with patients with a SDAVF and feeding artery identified on CE-TR MRA, patients with negative or suboptimal CE-TR MRA had a significantly increased number of vessels catheterized (p=0.027) and larger contrast volumes (p=0.022).ConclusionsCE-TR MRA is a useful initial examination for the diagnosis and localization of SDAVFs, with a high concordance rate with DSA. When CE-TR MRA demonstrates a SDAVF, the number of catheterized vessels and contrast dose can be decreased during DSA.
BRAF Inhibitor Resistance Mechanisms in Metastatic Melanoma: Spectrum and Clinical Impact
Authors: Rizos Helen , Menzies Alexander M. , Pupo Gulietta M. , Carlino Matteo S. , Fung Carina , Hyman Jessica , Haydu Lauren E. , Mijatov Branka , Becker Therese M. , Boyd Suzanah C. , Howle Julie , Saw Robyn , Thompson John F. , Kefford Richard F. , Scolyer Richard A. , Long Georgina V. 
Published: January 2014

Abstract
Purpose: Multiple BRAF inhibitor resistance mechanisms have been described, however, their relative frequency, clinical correlates, and effect on subsequent therapy have not been assessed in patients with metastatic melanoma.
Experimental Design: Fifty-nine BRAFV600-mutant melanoma metastases from patients treated with dabrafenib or vemurafenib were analyzed. The genetic profile of resistance mechanisms and tumor signaling pathway activity was correlated with clinicopathologic features and therapeutic outcomes.
Results: Resistance mechanisms were identified in 58% progressing tumors and BRAF alterations were common. Gene expression analysis revealed that mitogen-activated protein kinase (MAPK) activity remained inhibited in 21% of resistant tumors, and the outcomes of patients with these tumors were poor. Resistance mechanisms also occurred in pretreatment biopsies and heterogeneity of resistance mechanisms occurred within patients and within tumors. There were no responses to subsequent targeted therapy, even when a progressing tumor had a resistance mechanism predicted to be responsive.
Conclusions: Selecting sequential drugs based on the molecular characteristics of a single progressing biopsy is unlikely to provide improved responses, and first-line therapies targeting multiple pathways will be required. Clin Cancer Res; 20(7); 1965–77. ©2014 AACR.
Activation of Peroxisome Proliferator-Activated Receptor-β/δ (PPAR-β/δ) Inhibits Human Breast Cancer Cell Line Tumorigenicity
Authors: Yao Pei-Li , Morales Jose L. , Zhu Bokai , Kang Boo-Hyon , Gonzalez Frank J. , Peters Jeffrey M. 
Published: January 2014

Abstract
The effect of activation and overexpression of the nuclear receptor PPAR-β/δ in human MDA-MB-231 (estrogen receptor–negative; ER−) and MCF7 (estrogen-receptor-positive; ER+) breast cancer cell lines was examined. Target gene induction by ligand activation of PPAR-β/δ was increased by overexpression of PPAR-β/δ compared with controls. Overexpression of PPAR-β/δ caused a decrease in cell proliferation in MCF7 and MDA-MB-231 cells compared with controls, whereas ligand activation of PPAR-β/δ further inhibited proliferation of MCF7 but not MDA-MB-231 cells. Overexpression and/or ligand activation of PPAR-β/δ in MDA-MB-231 or MCF7 cells had no effect on experimental apoptosis. Decreased clonogenicity was observed in both MDA-MB-231 and MCF7 overexpressing PPAR-β/δ in response to ligand activation of PPAR-β/δ as compared with controls. Ectopic xenografts developed from MDA-MB-231 and MCF7 cells overexpressing PPAR-β/δ were significantly smaller, and ligand activation of PPAR-β/δ caused an even greater reduction in tumor volume as compared with controls. Interestingly, the decrease in MDA-MB-231 tumor size after overexpressing PPAR-β/δ and ligand activation of PPAR-β/δ correlated with increased necrosis. These data show that ligand activation and/or overexpression of PPAR-β/δ in two human breast cancer cell lines inhibits relative breast cancer tumorigenicity and provide further support for the development of ligands for PPAR-β/δ to specifically inhibit breast carcinogenesis. These new cell-based models will be invaluable tools for delineating the role of PPAR-β/δ in breast cancer and evaluating the effects of PPAR-β/δ agonists. Mol Cancer Ther; 13(4); 1008–17. ©2014 AACR.