bluuebunny/crossref_metadata_2025_split huggingface dataset:
The
Vibrio cholerae
VexGH RND Efflux System Maintains Cellular Homeostasis by Effluxing Vibriobactin
Authors: Kunkle Dillon E. , Bina X. Renee , Bina James E. 
Published: May 2017

ABSTRACT

Resistance-nodulation-division (RND) superfamily efflux systems have been widely studied for their role in antibiotic resistance, but their native biological functions remain poorly understood. We previously showed that loss of RND-mediated efflux in
Vibrio cholerae
resulted in activation of the Cpx two-component regulatory system, which mediates adaptation to stress resulting from misfolded membrane proteins. Here, we investigated the mechanism linking RND-mediated efflux to the Cpx response. We performed transposon mutagenesis screening of RND-deficient
V. cholerae
to identify Cpx suppressors. Suppressor mutations mapped to genes involved in the biosynthesis of the catechol siderophore vibriobactin. We subsequently demonstrated that vibriobactin secretion is impaired in mutants lacking the VexGH RND efflux system and that impaired vibriobactin secretion is responsible for Cpx system activation, suggesting that VexGH secretes vibriobactin. This conclusion was bolstered by results showing that
vexGH
expression is induced by iron limitation and that
vexH
-deficient cells exhibit reduced fitness during growth under iron-limiting conditions. Our results support a model where VexGH contributes to cellular homeostasis by effluxing vibriobactin. In the absence of
vexGH
, retained vibriobactin appears to chelate iron from iron-rich components of the respiratory chain, with the deferrated proteins functioning to activate the Cpx response. Our collective results demonstrate that a native function of the
V. cholerae
VexGH RND efflux system is in vibriobactin secretion and that vibriobactin efflux is critical for maintenance of cellular homeostasis.

IMPORTANCE
RND efflux systems are ubiquitous Gram-negative transporters that play critical roles in antimicrobial resistance. In addition to antimicrobial resistance, RND transporters also affect the expression of diverse phenotypes, including virulence, cell metabolism, and stress responses. The latter observations suggest that RND transporters fulfill unknown physiological functions in the cell independently of their role in antimicrobial resistance.
Vibrio cholerae
is representative of many Gram-negative bacteria in encoding multiple RND transporters that are redundant in antimicrobial resistance and affect multiple phenotypes. Here we describe a novel function of the
V. cholerae
VexGH RND transporter in vibriobactin secretion. We show that vibriobactin production in VexGH-deficient cells impacts cell homeostasis, leading to activation of the Cpx stress response and reduced fitness under iron-limiting conditions. Our results highlight a native physiological function of an RND transporter and provide insight into the selective forces that maintain what was thought to be a redundant multidrug transporter.
Intrinsic Toxin-Derived Peptides Destabilize and Inactivate
Clostridium difficile
TcdB
Authors: Larabee Jason L. , Bland Sarah J. , Hunt Jonathan J. , Ballard Jimmy D. 
Published: May 2017

ABSTRACT

Clostridium difficile
infection (CDI) is a major cause of hospital-associated, antibiotic-induced diarrhea, which is largely mediated by the production of two large multidomain clostridial toxins, TcdA and TcdB. Both toxins coordinate the action of specific domains to bind receptors, enter cells, and deliver a catalytic fragment into the cytosol. This results in GTPase inactivation, actin disassembly, and cytotoxicity. TcdB in particular has been shown to encode a region covering amino acids 1753 to 1851 that affects epitope exposure and cytotoxicity. Surprisingly, studies here show that several peptides derived from this region, which share the consensus sequence
1769
NVFKGNTISDK
1779
, protect cells from the action of TcdB. One peptide, PepB2, forms multiple interactions with the carboxy-terminal region of TcdB, destabilizes TcdB structure, and disrupts cell binding. We further show that these effects require PepB2 to form a higher-order polymeric complex, a process that requires the central GN amino acid pair. These data suggest that TcdB
1769–1779
interacts with repeat sequences in the proximal carboxy-terminal domain of TcdB (i.e., the CROP domain) to alter the conformation of TcdB. Furthermore, these studies provide insights into TcdB structure and functions that can be exploited to inactivate this critical virulence factor and ameliorate the course of CDI.

IMPORTANCE
Clostridium difficile
is a leading cause of hospital-associated illness that is often associated with antibiotic treatment. To cause disease,
C. difficile
secretes toxins, including TcdB, which is a multidomain intracellular bacterial toxin that undergoes conformational changes during cellular intoxication. This study describes the development of peptide-based inhibitors that target a region of TcdB thought to be critical for structural integrity of the toxin. The results show that peptides derived from a structurally important region of TcdB can be used to destabilize the toxin and prevent cellular intoxication. Importantly, this work provides a novel means of toxin inhibition that could in the future develop into a
C. difficile
treatment.
Structure-Based Mutations in the Herpes Simplex Virus 1 Glycoprotein B Ectodomain Arm Impart a Slow-Entry Phenotype
Authors: Fan Qing , Kopp Sarah J. , Connolly Sarah A. , Longnecker Richard 
Published: May 2017

ABSTRACT
Glycoprotein B (gB) is the conserved herpesvirus fusion protein, and it is required for the entry of herpesviruses. The structure of the postfusion conformation of gB has been solved for several herpesviruses; however, the gB prefusion crystal structure and the details of how the protein refolds from a prefusion to a postfusion form to mediate fusion have not been determined. Using structure-based mutagenesis, we previously reported that three mutations (I671A, H681A, and F683A) in the C-terminal arm of the gB ectodomain greatly reduced cell-cell fusion. This fusion deficit could be rescued by the addition of a hyperfusogenic mutation, suggesting that the gB triple mutant was not misfolded. Using a bacterial artificial chromosome (BAC), we constructed two independent herpes simplex virus 1 mutant strains (gB 3A) carrying the three arm mutations. The gB 3A viruses have 200-fold smaller plaques than the wild-type virus and demonstrate remarkably delayed entry into cells. Single-step and multistep growth curves show that gB 3A viruses have delayed replication kinetics. Interestingly, incubation at 40°C promoted the entry of the gB 3A viruses. We propose that the gB 3A viruses’ entry deficit is due to a loss of interactions between residues in the gB C-terminal arm and the coiled-coil core of gB. The results suggest that the triple alanine mutation may destabilize the postfusion gB conformation and/or stabilize the prefusion gB conformation and that exposure to elevated temperatures can overcome the defect in gB 3A viruses.

IMPORTANCE
Because of its complexity, the mechanism of herpesvirus entry into cells is not well understood. Our study investigated one of the most important unanswered questions about herpesvirus entry; i.e., how does the herpesvirus fusion protein gB mediate membrane fusion? gB is an essential protein that is conserved in all herpesviruses and is thought to undergo a conformational change to provide the energy to fuse the viral and cellular membranes. Using our understanding of the structure of gB, we designed mutations in the gB “arm” region that we predicted would impede gB function. We introduced these mutations into herpes simplex virus 1 by using a bacterial artificial chromosome, and the mutant virus exhibited a drastically delayed rate of entry. This entry defect was rescued by incubation at elevated temperatures, supporting a hypothesis that the engineered mutations altered the energetics of gB refolding. This study supports our hypothesis that an interaction between the gB arm and the core of gB is critical for gB refolding and the execution of membrane fusion, thus providing key details about the function of gB in herpesvirus-mediated fusion and subsequent virus entry.
The functional movement test 9+ is a poor screening test for lower extremity injuries in professional male football players: a 2-year prospective cohort study
Authors: Bakken Arnhild , Targett Stephen , Bere Tone , Eirale Cristiano , Farooq Abdulaziz , Tol Johannes L , Whiteley Rod , Khan Karim M , Bahr Roald 
Published: May 2017

BackgroundThe 9+ screening battery test consists of 11 tests to assess limitations in functional movement.AimTo examine the association of the 9+ with lower extremity injuries and to identify a cut-off point to predict injury risk.MethodsProfessional male football players in Qatar from 14 teams completed the 9+ at the beginning of the 2013/2014 and 2014/2015 seasons. Time-loss injuries and exposure in training and matches were registered prospectively by club medical staff during these seasons. Univariate and multivariate Cox regression analyses were used to calculate HR and 95% CI. Receiver operating characteristic (ROC) curves were calculated to determine sensitivity and specificity and identify the optimal cut-off point for risk assessment.Results362 players completed the 9+ and had injury and exposure registration. There were 526 injuries among 203 players (56.1%) during the two seasons; injuries to the thigh were the most frequent. There was no association between 9+ total score and the risk of lower extremity injuries (HR 1.02, 95% CI 0.99 to 1.05, p=0.13), even after adjusting for other risk factors in a multivariate analysis (HR 1.01, 95% CI 0.98 to 1.04, p=0.37). ROC curve analysis revealed an area under the curve of 0.48, and there was no cut-off point that distinguished injured from non-injured players.ConclusionThe 9+ was not associated with lower extremity injury, and it was no better than chance for distinguishing between injured and uninjured players. Therefore, the 9+ test cannot be recommended as an injury prediction tool in this population.
A specialty-specific, multimodality educational quality improvement initiative to deimplement rarely appropriate myocardial perfusion imaging
Authors: Winchester David E , Schmalfuss Carsten , Helfrich Christian D , Beyth Rebecca J 
Published: May 2017

ObjectiveInvestigations of Appropriate Use Criteria (AUC) education have shown a mixed effect on changing provider behaviour. At our facility, rarely appropriate myocardial perfusion imaging (MPI) differs by specialty; awareness of AUC is low. Our objective is to investigate if specialty-specific, multimodality education could reduce rarely appropriate MPI.MethodsWe designed education focused on the rarely appropriate MPI ordered most often by each specialty. We tracked appropriateness of MPI in three cohorts: pre, post (immediately after) and late-post (4 months after) intervention.ResultsA total of 889 MPI were evaluated (n=287 pre, n=313 post, n=289 late-post), 95.3% were men. Chest pain was the most common symptom (n=530, 59.6%), while 14.1% (n=125) had no symptoms. Rarely appropriate testing decreased from 4.9% to 1.3% and remained at 1.4% in the late-post cohort (p<0.0001). In logistic regression, lack of symptoms (OR 31.3, 95% CI 10.3 to 94.8, p≤0.0001) and being in the post or late-post cohorts (OR 0.27, 95% CI 0.11 to 0.68, p=0.006) were associated with rarely appropriate MPI. Preoperative MPI in patients with good exercise capacity was a common rarely appropriate indication. Ischaemia was not observed among patients with rarely appropriate indication for MPI.ConclusionsIn certain clinical settings, education may be an effective approach for deimplementing rarely appropriate MPI. The effect of education may be enhanced when focused on improving patient care, delivered by a peer, and needs assessment indicates low awareness of guidelines. Lack of symptoms and preoperative MPI continue to be the predominant rarely appropriate MPI ordered.
Unsuccessful resuscitation with epinephrine in a dog with suspected severe perioperative anaphylaxis
Authors: Sasaki Kazumasu , Mutoh Tatsushi , Shiga Takuya , Gómez de Segura Ignacio Álvarez 
Published: May 2017

An 11‐month‐old ASA 1 male miniature dachshund was anaesthetised for neutering. Butorphanol and midazolam were administered as preanaesthetic medication along with cefazolin. Anaesthesia was induced with propofol and maintained with isoflurane. Latex products (surgical gloves and a breathing bag) were used intraoperatively. Intraoperative vital signs were within normal ranges. Approximately 5 min after extubation, the dog developed intense urticarial erythema, hypotension and pulmonary oedema. First‐line treatment with repeated intramuscular epinephrine, oxygenation, fluid loading, corticosteroids and antihistamines to address severe hypotension was unsuccessful. Additional vasopressin, continuous epinephrine infusion, mechanical ventilation and cardiopulmonary resuscitation proved unsuccessful and the owners opted for euthanasia. The causative agent remains unclear; serological or skin tests were not performed. This is the first report of severe perioperative anaphylactic shock in a dog unresponsive to current therapeutic recommendations based on epinephrine administration. Further research is warranted to advance clinical guidelines for managing anaphylaxis in dogs.
Transversus abdominis plane block in two calves undergoing umbilical herniorrhaphy
Authors: Zoff Aurora , Dugdale Alex , Coates A N , Rioja Eva 
Published: May 2017

A transversus abdominis plane (TAP) block was performed in two calves undergoing umbilical hernia repair. Both calves were in good health and body condition and were anaesthetised using standard anaesthesia protocols. After placement in dorsal recumbency, the abdomen was scanned with an 11‐MHz linear array probe from the last rib to the iliac crest to identify the abdominal musculature comprising the external and internal abdominal oblique muscles and the transversus abdominis (TA). The needle (SonoTAP cannula 22G×50 mm; Pajunk) was advanced using an in‐plane technique, and a volume of 0.3 ml/kg was injected after a test dose. No obvious reduction of isoflurane requirements was apparent and one of the calves required rescue analgesia. The calves recovered uneventfully from anaesthesia.This case report discusses the advantages of the TAP block over the paravertebral block, discusses the risks associated with TAP blocks and highlights the importance of training in ultrasound‐guided techniques.
Effects of laser power on the microstructure and mechanical properties of 316L stainless steel prepared by selective laser melting
Authors: Zheng Zeng , Wang Lianfeng , Yan Biao 
Published: May 2017

Selective laser melting (SLM) was used to prepare 316L stainless steel parts and the effects of laser power on the microstructure and mechanical properties of the final products were studied. With increasing applied laser power, the defects of as-built parts were reduced greatly and the as-built parts presented a highest relative density of 99.1%. The tensile strength of samples was significantly improved from 321 ± 10 MPa to 722 ± 10 MPa. The microhardness was homogeneous; the residual stresses in the samples were tensile, which were higher in the section perpendicular to the laser scanning strategy. The probable reasons for this phenomenon were proposed.
Can Microsatellite Status of Colorectal Cancer Be Reliably Assessed after Neoadjuvant Therapy?
Authors: Goldstein Jennifer B. , Wu William , Borras Ester , Masand Gita , Cuddy Amanda , Mork Maureen E. , Bannon Sarah A. , Lynch Patrick M. , Rodriguez-Bigas Miguel , Taggart Melissa W. , Wu Ji , Scheet Paul , Kopetz Scott , You Y. Nancy , Vilar Eduardo 
Published: May 2017

Abstract
Purpose: Determination of microsatellite instability (MSI) by PCR is the gold standard; however, IHC of mismatch repair (MMR) proteins is frequently performed instead. The reliability of these methods on postneoadjuvant therapy specimens is unknown. We examined the effect of neoadjuvant therapy on MSI results by PCR and IHC.
Experimental design: A total of 239 colorectal cancers resected after neoadjuvant therapy were assessed for MSI with PCR and IHC. PCR and IHC results for matched paired pre- and posttreatment specimens were compared. In parallel, 2 isogenic cell lines conditioned for MMR functioning and 2 different patient-derived xenografts (PDXs) were exposed to chemotherapy, radiation, or both. We also examined whether establishment of PDXs induced MSI changes in 5 tumors. IHC and MSI were tested after treatment to assess for changes.
Results: We identified paired pre- and posttreatment specimens for 37 patients: 2 with PCR only, 34 with IHC only, and 1 with both. All 3 patients with PCR had microsatellite stable pre- and posttreatment specimens. Of the 35 patients with IHC, 30 had intact MMR proteins in pre- and posttreatment specimens, 1 had equivocal MLH1 staining in the pretreatment and loss in the posttreatment specimen, and 4 had intact pretreatment MSH6 but variable posttreatment staining. In the experimental setting, no changes in MSI status were detected after treatment or tumor implantation in animals.
Conclusions: Our findings show that the expression of MMR proteins, commonly MSH6, can change after neoadjuvant therapy and confirm PCR as the gold-standard test for MSI after neoadjuvant therapy. Clin Cancer Res; 23(17); 5246–54. ©2017 AACR.
Clinical Utility of Risk Models to Refer Patients with Adnexal Masses to Specialized Oncology Care: Multicenter External Validation Using Decision Curve Analysis
Authors: Wynants Laure , Timmerman Dirk , Verbakel Jan Y. , Testa Antonia , Savelli Luca , Fischerova Daniela , Franchi Dorella , Van Holsbeke Caroline , Epstein Elisabeth , Froyman Wouter , Guerriero Stefano , Rossi Alberto , Fruscio Robert , Leone Francesco PG , Bourne Tom , Valentin Lil , Van Calster Ben 
Published: May 2017

Abstract
Purpose: To evaluate the utility of preoperative diagnostic models for ovarian cancer based on ultrasound and/or biomarkers for referring patients to specialized oncology care. The investigated models were RMI, ROMA, and 3 models from the International Ovarian Tumor Analysis (IOTA) group [LR2, ADNEX, and the Simple Rules risk score (SRRisk)].
Experimental Design: A secondary analysis of prospectively collected data from 2 cross-sectional cohort studies was performed to externally validate diagnostic models. A total of 2,763 patients (2,403 in dataset 1 and 360 in dataset 2) from 18 centers (11 oncology centers and 7 nononcology hospitals) in 6 countries participated. Excised tissue was histologically classified as benign or malignant. The clinical utility of the preoperative diagnostic models was assessed with net benefit (NB) at a range of risk thresholds (5%–50% risk of malignancy) to refer patients to specialized oncology care. We visualized results with decision curves and generated bootstrap confidence intervals.
Results: The prevalence of malignancy was 41% in dataset 1 and 40% in dataset 2. For thresholds up to 10% to 15%, RMI and ROMA had a lower NB than referring all patients. SRRisks and ADNEX demonstrated the highest NB. At a threshold of 20%, the NBs of ADNEX, SRrisks, and RMI were 0.348, 0.350, and 0.270, respectively. Results by menopausal status and type of center (oncology vs. nononcology) were similar.
Conclusions: All tested IOTA methods, especially ADNEX and SRRisks, are clinically more useful than RMI and ROMA to select patients with adnexal masses for specialized oncology care. Clin Cancer Res; 23(17); 5082–90. ©2017 AACR.
Herpes Simplex Virus Glycoprotein D Targets a Specific Dendritic Cell Subset and Improves the Performance of Vaccines to Human Papillomavirus-Associated Tumors
Authors: Porchia Bruna F.M.M. , Moreno Ana Carolina R. , Ramos Rodrigo N. , Diniz Mariana O. , de Andrade Laís Helena T.M. , Rosa Daniela S. , Barbuto José Alexandre M. , Boscardin Silvia B. , Ferreira Luís Carlos S. 
Published: May 2017

Abstract
Cervical cancer is a major public health problem and one of the leading causes of cancer deaths in women. Virtually all cases of cervical cancer, as well as a growing share of anal and head/neck tumors, are associated with human papillomavirus (HPV) infection. Despite the effectiveness, the available prophylactic vaccines do not benefit women with cervical lesions or cancer. Therefore, the search of new immunotherapeutic approaches to treat HPV-induced tumors is still a priority. The present study characterizes a therapeutic antitumor vaccine based on the genetic fusion of the Herpes simplex virus-1 (HSV-1) glycoprotein D (gD) with the E7 oncoprotein from HPV-16 (gDE7). Two subcutaneous doses of gDE7, admixed with poly (I:C), conferred complete and long-lasting therapeutic antitumor protection on mice previously challenged with tumor cells expressing the HPV-16 oncoproteins. The vaccine induced multifunctional E7-specific CD8+ T cells with cytotoxic activity and effector memory phenotype (CD44+ CD62Llow). In addition, gDE7 admixed with poly (I:C) vaccination controlled the expansion of tumor-induced regulatory T cells and myeloid-derived suppressor cells. More importantly, gDE7 activated mouse CD11c+ CD8α+ and human BDCA3+ dendritic cells (DC), specialized in antigen cross-presentation to CD8+ T cells, under in vitro conditions. These results indicated that the activation of a specific DC population, mediated by gD, improved the antigen-specific immune responses and the therapeutic performance induced by antitumor vaccines. These results open perspectives for the clinical testing of gDE7-based vaccines under the concept of active immunization as a tool for the therapeutic control of cancer. Mol Cancer Ther; 16(9); 1922–33. ©2017 AACR.
ПОРІВНЯЛЬНА ХАРАКТЕРИСТИКА КЛІНІЧНОЇ ЕФЕКТИВНОСТІ РІЗНИХ СХЕМ ЛІКУВАННЯ АТОПІЧНОГО ДЕРМАТИТУ У ДІТЕЙ, ОСОБЛИВОСТІ ЗАСТОСУВАННЯ СПЕЦИФІЧНОЇ ІНДУКЦІЇ ІМУНОЛОГІЧНОЇ ТОЛЕРАНТНОСТІ
Authors: Mochulska O. M. 
Published: May 2017

Мета дослідження:вивчення ефективності та оцінка перспективи застосування алерген-специфічної імунотерапії в поєднанні із пролонгованою пробіотикотерапією при атопічному дерматиті у дітей, як методу індукції імунологічної толерантності, аналіз досвіду клінічної практики та інтерпретація результатів обстежень.Матеріали та методи. В процесі виконання науково-дослідної роботи усім дітям були проведені загально-клінічні методи дослідження: оцінка скарг, анамнестичних даних, об’єктивного статусу пацієнтів із визначенням показників фізичного розвитку, загальні клініко-лабораторні і біохімічні, імунологічні, алергологічні, інструментальні методи дослідження, такі як УЗД шкіри і дерматоскопія. Проводили порівняльну оцінку ефективності традиційної терапії та комплексного лікування атопічного дерматиту із застосуванням алерген-специфічної імунотерапії та пролонгованого курсу пробіотиками у 108 дітей віком від 4 до 18 років, контрольну групу склали 34 дітей аналогічного віку з хворими.Результати дослідження та їх обговорення. В статті представлені дані про перспективи застосування алерген-специфічної імунотерапії в поєднанні із пробіотикотерапією при атопічному дерматиті у педіатрії, а також наведено результати власних досліджень ефективності запропонованої терапії у дітей із атопічним дерматитом віком від 4 до 18 років. Проведено оцінку і порівняння традиційної терапії та алерген-специфічної імунотерапії в поєднанні із пробіотикотерапією при атопічному дерматиті. Контроль якості і ефективності комплексної терапії проводився за даними імунограми, а саме показників клітинної і гуморальної ланок імунітету, цитокінового статусу та рівня сироваткових імуноглобулінів.Висновки.Обгрунтовано доцільність та перспективу застосування алерген-специфічної імунотерапії в поєднанні із пролонгованою пробіотикотерапією у дітей з атопічним дерматитом.