bluuebunny/crossref_metadata_2025_split huggingface dataset:
A functional role for the ‘fibroblast‐like cells’ in gastrointestinal smooth muscles
Authors: Kurahashi Masaaki , Zheng Haifeng , Dwyer Laura , Ward Sean M. , Don Koh Sang , Sanders Kenton M. 
Published: December 2010

Non‐technical summarySmooth muscles, as in the gastrointestinal tract, are composed of several types of cells. Gastrointestinal muscles contain smooth muscle cells, enteric neurons, glial cells, immune cells, and various classes of interstitial cells. One type of interstitial cell, referred to as ‘fibroblast‐like cells’ by morphologists, are common, but their function is unknown. These cells are found near the terminals of enteric motor neurons, suggesting they could have a role in generating neural responses that help control gastrointestinal movements. We used a novel mouse with bright green fluorescent protein expressed specifically in the fibroblast‐like cells to help us identify these cells in the mixture of cells obtained when whole muscles are dispersed with enzymes. We isolated these cells and found they respond to a major class of inhibitory neurotransmitters – purines. We characterized these responses, and our results provide a new hypothesis about the role of fibroblast‐like cells in smooth muscle tissues.
Site-Specific Mutation of
Staphylococcus aureus
VraS Reveals a Crucial Role for the VraR-VraS Sensor in the Emergence of Glycopeptide Resistance
Authors: Galbusera Elena , Renzoni Adriana , Andrey Diego O. , Monod Antoinette , Barras Christine , Tortora Paolo , Polissi Alessandra , Kelley William L. 
Published: December 2010

ABSTRACT

An initial response of
Staphylococcus aureus
to encounter with cell wall-active antibiotics occurs by transmembrane signaling systems that orchestrate changes in gene expression to promote survival. Histidine kinase two-component sensor-response regulators such as VraRS contribute to this response. In this study, we examined VraS membrane sensor phosphotransfer signal transduction and explored the genetic consequences of disrupting signaling by engineering a site-specific
vraS
chromosomal mutation. We have used
in vitro
autophosphorylation assay with purified VraS[64-347] lacking its transmembrane anchor region and tested site-specific kinase domain histidine mutants. We identified VraS H156 as the probable site of autophosphorylation and show phosphotransfer
in vitro
using purified VraR. Genetic studies show that the
vraS
(
H156A
) mutation in three strain backgrounds (ISP794, Newman, and COL) fails to generate detectable first-step reduced susceptibility teicoplanin mutants and severely reduces first-step vancomycin mutants. The emergence of low-level glycopeptide resistance in strain ISP794, derived from strain 8325 (Δ
rsbU
), did not require a functional σ
B
, but
rsbU
restoration could enhance the emergence frequency supporting a role for this alternative sigma factor in promoting glycopeptide resistance. Transcriptional analysis of
vraS
(
H156A
) strains revealed a pronounced reduction but not complete abrogation of the
vraRS
operon after exposure to cell wall-active antibiotics, suggesting that additional factors independent of VraS-driven phosphotransfer, or σ
B
, exist for this promoter. Collectively, our results reveal important details of the VraRS signaling system and predict that pharmacologic blockade of the VraS sensor kinase will have profound effects on blocking emergence of cell wall-active antibiotic resistance in
S. aureus
.
In Vitro
Effect of
qnrA1
,
qnrB1
, and
qnrS1
Genes on Fluoroquinolone Activity against Isogenic
Escherichia coli
Isolates with Mutations in
gyrA
and
parC
Authors: Briales A. , Rodríguez-Martínez J. M. , Velasco C. , Díaz de Alba P. , Domínguez-Herrera J. , Pachón J. , Pascual A. 
Published: December 2010

ABSTRACT

This article provides an analysis of the
in vitro
effect of
qnrA1
,
qnrB1
, and
qnrS1
genes, combined with quinolone-resistant Ser83Leu substitutions in GyrA and/or Ser80Arg in ParC, on fluoroquinolone (FQ) resistance in isogenic
Escherichia coli
strains. The association of Ser83Leu substitution in GyrA, Ser80Arg substitution in ParC, and
qnr
gene expression increased the MIC of ciprofloxacin to 2 μg/ml.
qnr
genes present in
E. coli
that harbored a Ser83Leu substitution in GyrA increased mutant prevention concentration (MPC) values to 8 to 32 μg/ml.
qnr
gene expression in
E. coli
may play an important role in selecting for one-step FQ-resistant mutants.
Complete Nucleotide Sequence of Plasmid pTN48, Encoding the CTX-M-14 Extended-Spectrum β-Lactamase from anEscherichia coliO102-ST405 Strain
Authors: Billard-Pomares Typhaine , Tenaillon Olivier , Le Nagard Hervé , Rouy Zoé , Cruveiller Stéphane , Médigue Claudine , Arlet Guillaume , Denamur Erick , Branger Catherine 
Published: December 2010

ABSTRACTThe sequence of pTN48, a plasmid of the FII-FIB replicon type that encodes a CTX-M-14 enzyme in anEscherichia colistrain of the phylogenetic group D2O102-ST405 clone, was determined. pTN48 is, for the most part, a mosaic of virulence, antibiotic resistance, and addiction system modules found in various other plasmids. The presence of multiple addiction systems indicates that the plasmid should be stably maintained in theE. coliclone, favoring dissemination of the CTX-M-14 enzyme.
Inhibitors of Endoplasmic Reticulum α-Glucosidases Potently Suppress Hepatitis C Virus Virion Assembly and Release
Authors: Qu Xiaowang , Pan Xiaoben , Weidner Jessica , Yu Wenquan , Alonzi Dominic , Xu Xiaodong , Butters Terry , Block Timothy , Guo Ju-Tao , Chang Jinhong 
Published: December 2010

ABSTRACT
α-Glucosidases I and II are endoplasmic reticulum-resident enzymes that are essential for N-linked glycan processing and subsequent proper folding of glycoproteins. In this report, we first demonstrate that downregulation of the expression of α-glucosidase I, II, or both in Huh7.5 cells by small hairpin RNA technology inhibited the production of hepatitis C virus (HCV). In agreement with the essential role of α-glucosidases in HCV envelope glycoprotein processing and folding, treatment of HCV-infected cells with a panel of imino sugar derivatives, which are competitive inhibitors of α-glucosidases, did not affect intracellular HCV RNA replication and nonstructural protein expression but resulted in the inhibition of glycan processing and subsequent degradation of HCV E2 glycoprotein. As a consequence, HCV virion assembly and secretion were inhibited. In searching for imino sugars with better antiviral activity, we found that a novel imino sugar, PBDNJ0804, had a superior ability to inhibit HCV virion assembly and secretion. In summary, we demonstrated that glucosidases are important host factor-based antiviral targets for HCV infection. The low likelihood of drug-resistant virus emergence and potent antiviral efficacy of the novel glucosidase inhibitor hold promise for its development as a therapeutic agent for the treatment of chronic hepatitis C.
Analysis of Low-Frequency Mutations Associated with Drug Resistance to Raltegravir before Antiretroviral Treatment
Authors: Liu Jia , Miller Michael D. , Danovich Robert M. , Vandergrift Nathan , Cai Fangping , Hicks Charles B. , Hazuda Daria J. , Gao Feng 
Published: December 2010

ABSTRACTRaltegravir is highly efficacious in the treatment of HIV-1 infection. The prevalence and impact on virologic outcome of low-frequency resistant mutations among HIV-1-infected patients not previously treated with raltegravir have not been fully established. Samples from HIV treatment-experienced patients entering a clinical trial of raltegravir treatment were analyzed using a parallel allele-specific sequencing (PASS) assay that assessed six primary and six secondary integrase mutations. Patients who achieved and sustained virologic suppression (success patients,n= 36) and those who experienced virologic rebound (failure patients,n= 35) were compared. Patients who experienced treatment failure had twice as many raltegravir-associated resistance mutations prior to initiating treatment as those who achieved sustained virologic success, but the difference was not statistically significant. The frequency of nearly all detected resistance mutations was less than 1% of viral population, and the frequencies of mutations between the success and failure groups were similar. Expansion of pre-existing mutations (one primary and five secondary) was observed in 16 treatment failure patients in whom minority resistant mutations were detected at baseline, suggesting that they might play a role in the development of drug resistance. Two or more mutations were found in 13 patients (18.3%), but multiple mutations were not present in any single viral genome by linkage analysis. Our study demonstrates that low-frequency primary RAL-resistant mutations were uncommon, while minority secondary RAL-resistant mutations were more frequently detected in patients naïve to raltegravir. Additional studies in larger populations are warranted to fully understand the clinical implications of these mutations.
BB0844, an RpoS-Regulated Protein, Is Dispensable for
Borrelia burgdorferi
Infectivity and Maintenance in the Mouse-Tick Infectious Cycle
Authors: Banik Sukalyani , Terekhova Darya , Iyer Radha , Pappas Christopher J. , Caimano Melissa J. , Radolf Justin D. , Schwartz Ira 
Published: December 2010

ABSTRACT

The genome of
Borrelia burgdorferi
, the causative agent of Lyme disease, is comprised of a large linear chromosome and numerous smaller linear and circular plasmids.
B. burgdorferi
exhibits substantial genomic variation, and previous studies revealed genotype-specific variation at the right chromosomal telomere. A correlation has also been established between genotype and invasiveness. The correlation between chromosome length and genotype and between genotype and invasiveness suggested that a gene(s) at the right chromosome telomere may be required for virulence. Of particular interest was
bb0844
, an RpoS-regulated gene at the right telomere, the expression of which is induced when the spirochete undergoes adaptation to the mammalian host. The structure of the right chromosomal telomere was examined in 53
B. burgdorferi
clinical isolates of various genotypes. Four distinct patterns were observed for
bb0844
: (i) chromosomal localization, (ii) plasmid localization, (iii) presence on both chromosome and plasmid, and (iv) complete absence. These patterns correlated with the
B. burgdorferi
genotype. On the basis of available sequence data, we propose a mechanism for the genomic rearrangements that accounts for the variability in
bb0844
genomic localization. To further explore the role of BB0844 in the spirochete life cycle, a
bb0844
deletion mutant was constructed by allelic exchange, and the viability of wild-type and
bb0844
deletion mutants was examined in an experimental mouse-tick infection model. The
bb0844
mutant was fully infectious in C3H/HeJ mice by either needle inoculation or tick transmission with
B. burgdorferi
-infected
Ixodes scapularis
larvae. Naïve larval ticks acquired both wild-type and mutant spirochetes with equal efficiency from
B. burgdorferi
-infected mice. The results demonstrate that BB0844 is not required for spirochete viability, pathogenicity, or maintenance in the tick vector or the mammalian host. At present, a defined role for BB0844 in
B. burgdorferi
cannot be ascertained.
Invasion of Eukaryotic Cells byBorrelia burgdorferiRequires β1Integrins and Src Kinase Activity
Authors: Wu Jing , Weening Eric H. , Faske Jennifer B. , Höök Magnus , Skare Jon T. 
Published: December 2010

ABSTRACTLyme disease, caused by the bacteriumBorrelia burgdorferi, is the most widespread tick-borne infection in the northern hemisphere that results in a multistage disorder with concomitant pathology, including arthritis. During late-stage experimental infection in mice,B. burgdorferievades the adaptive immune response despite the presence of borrelia-specific bactericidal antibodies. In this study we asked whetherB. burgdorfericould invade fibroblasts or endothelial cells as a mechanism to model the avoidance from humorally based clearance. A variation of the gentamicin protection assay, coupled with the detection of borrelial transcripts following gentamicin treatment, indicated that a portion ofB. burgdorfericells were protected in the short term from antibiotic killing due to their ability to invade cultured mammalian cells. Long-term coculture ofB. burgdorferiwith primary human fibroblasts provided additional support for intracellular protection. Furthermore, decreased invasion ofB. burgdorferiin murine fibroblasts that do not synthesize the β1integrin subunit was observed, indicating that β1-containing integrins are required for optimal borrelial invasion. However, β1-dependent invasion did not require either the α5β1integrin or the borrelial fibronectin-binding protein BBK32. The internalization ofB. burgdorferiwas inhibited by cytochalasin D and PP2, suggesting thatB. burgdorferiinvasion required the reorganization of actin filaments and Src family kinases (SFK), respectively. Taken together, these results suggest thatB. burgdorferican invade and retain viability in nonphagocytic cells in a process that may, in part, help to explain the phenotype observed in untreated experimental infection.
A Simple Wooden Ribosome Model: Helping Students Understand Transpeptidation
Authors: Klein Donald A. 
Published: December 2010

In teaching biology, it is critical to communicate broad concepts before considering more specific details of a process. This is particularly important when attempting to communicate the essence of transpeptidation, a key process in translation. Based on my experience in teaching general microbiology, transpeptidation is the most difficult aspect of translation for students to understand.
Typically, figures given in microbiology and biochemistry texts show movement of the nascent peptide attached to the P position t-RNA to the incoming single amino acid attached to the A position amino acid-tRNA by the use of arrows, an approach that makes it difficult to understand the dynamic aspects of this process. To attempt to improve understanding of this process, tutorials also are available that emphasize decoding “messages” and the use of “Do-it-Yourself DNA Kits” where the process of transpeptidation is not specifically discussed. The simple model described in this communication provides a clear demonstration of the transpeptidation process.
Clinical Microbiology in Pharmacy Education: A Practice-based Approach
Authors: Wasfi Olla , Power Mary , Slavcev Roderick A. 
Published: December 2010

The increasing incidence of multi-drug resistant pathogenic bacteria, alongside viral and fungal human pathogens, supports the argument that skills in microbiology and infectious disease diagnosis, treatment and prevention are of growing global importance to be held among primary care clinicians.In Canada, inevitable future astronomical health care costs largely due to an aging population, have forced eyes upon pharmacists as one of (if not) the primary clinical professions to accommodate the growing need to accommodate patient access to health care while maintaining lower health care costs. As such, the role of pharmacists in health care is expanding, punctuating the need to enhance and improve Pharmacy education. Accurate assessment of the current gaps in Pharmacy education in Canada provides a unique opportunity for a new Pharmacy School at the University of Waterloo to establish a non-traditional, outcomes-based model to curricular design. We are applying this iterative curriculum assessment and design process to the establishment of a Medical Microbiology program, deemed as a prominent gap in former Pharmacy educational training programs.A pilot study was carried out distributing a comprehensive survey to a local group of pharmacists practicing in a variety of settings including: hospital, clinic, community, independent, industry and government, to assess perceived gaps in Pharmacy microbiology and infectious disease education. Preliminary findings of the surveys indicate that practitioners feel under-qualified in some areas of microbiology. The results are discussed with respect to a curricular redesign model and next steps in the process of curricular design are proposed.
Expression of heparan sulfate in gastric carcinoma and its correlation with clinicopathological features and patient survival
Authors: Lo Soo-Ling , Thike Aye Aye , Tan Soo-Yong , Lim Tony Kiat-Hon , Tan Iain Bee-Huat , Choo Su-Pin , Tan Puay-Hoon , Bay Boon-Huat , Yip George Wai-Cheong 
Published: December 2010

AimTo determine the expression pattern and prognostic value of heparan sulfate in gastric cancer.MethodThe 10E4 antiheparan sulfate monoclonal antibody was used to examine the expression pattern of heparan sulfate in tissue microarrays consisting of 162 cases of gastric carcinoma by immunohistochemistry. The immunoreactivities of both epithelial and stromal components of the specimens were examined and analysed statistically for significant associations with clinicopathological parameters, including histological grade of the tumour, extent of cancer infiltration and presence of lymph-node metastases, lymphovascular invasion, perineural invasion, perforation of gastric wall and stromal reaction. The potential use of heparan sulfate as a predictive factor for patient survival was also evaluated.ResultsReduced expression of heparan sulfate in the epithelial component was associated with higher histological grades of gastric cancer as well as the presence of more extensive tumour infiltration. Furthermore, this decrease in heparan sulfate expression was found to be predictive of reduced patient survival after tumour recurrence.ConclusionThe data suggest that heparan sulfate may play an important role in regulating the biology of gastric cancer, and that it may be a useful prognostic marker of this tumour.
The effects of work-related maternal risk factors on time to pregnancy, preterm birth and birth weight: the Generation R Study
Authors: Burdorf A , Brand T , Jaddoe V W , Hofman A , Mackenbach J P , Steegers E A P 
Published: December 2010

ObjectiveTo investigate the influence of maternal working conditions on fertility and pregnancy outcomes.Methods8880 women were enrolled in a large prospective birth cohort during early (76%), mid (21%) or late pregnancy (3%) (61% participation). Complete questionnaire information was available for 6302 women (71% response). Outcomes were prolonged time to pregnancy (TTP) (>6 months), preterm birth (<37 weeks) and decreased birth weight (<3000 g). Self-reported exposure to chemical agents was based on a limited list of chemicals. Physical load questions concerned manual materials handling, prolonged sitting and long periods of standing. A job-exposure matrix (JEM) linked reported job title to workplace chemical exposure within jobs according to expert judgement. Associations between maternal occupational exposure and fertility and pregnancy outcomes, adjusted for age, education, minority, parity, smoking and alcohol use, were studied using logistic regression analysis.ResultsWomen in jobs with regular handling of loads ≥5 kg had better fertility and pregnancy outcomes. No self-reported exposure to chemicals was associated with any outcomes and self-assessments had very low reliability compared with JEM-based assessments. JEM-based maternal occupational exposure to phthalates was associated with prolonged TTP (OR 2.16, 95% CI 1.02 to 4.57) and exposure to pesticides was associated with decreased birth weight (OR 2.42, 95% CI 1.10 to 5.34). The population attributable fractions were small at 0.7% for phthalates and 0.7% for pesticides.ConclusionThis birth cohort study presents evidence of health-based selection into the workforce and adverse effects of maternal occupational exposure to phthalates and pesticides on fertility and pregnancy outcomes.
Smokers who are also using smokeless tobacco products in the US: a national assessment of characteristics, behaviours and beliefs of ‘dual users’: Table 1
Authors: McClave-Regan Annette K , Berkowitz Judy 
Published: December 2010

BackgroundMarketing and advertising of smokeless tobacco products towards cigarette smokers has increased recently. Because the use of multiple tobacco products is a growing public health concern, the present work assesses the use of smokeless tobacco among cigarette smokers, a behaviour termed as ‘dual use’, as well as attitudes and beliefs on their ‘dual use’ of tobacco.MethodsData were used from the 2008 ConsumerStyles survey, a nationally representative, mail-in survey of consumers in the USA (n=10 108).Results‘Dual use’ was more common among cigarette smokers who were young, white men living in the Midwest or South. The majority of ‘dual users’ reported using smokeless tobacco in places where they could not smoke (67.7%) and did not believe smokeless tobacco would help in quitting smoking (75.1%). ‘Dual users’ reported planning to quit within the next 6 months less often than adults who smoke cigarettes exclusively and close to half (42.3%) never plan to quit smoking.ConclusionsTobacco use is attributed to a number of diseases and deaths worldwide, and cessation of tobacco use can reduce these health risks. The prevalent use of smokeless tobacco in places with smoking restrictions and lack of planning to quit by ‘dual users’ suggest the need to promote cessation among these users.
Identification of three novel plasminogen (PLG) gene mutations in a series of 23 patients with low PLG activity
Authors: Klammt Jürgen , Kobelt Louise , Aktas Dilek , Durak Ismet , Gokbuget Aslan , Hughes Quintin , Irkec Murat , Kurtulus Idil , Lapi Elisabetta , Mechoulam Hadas , Mendoza-Londono Roberto , Palumbo Joseph , Steitzer Hansjörg , Tabbara Khalid , Ozbek Zeynep , Pucci Neri , Sotomayor Talia , Sturm Marian , Drogies Tim , Ziegler Maike , Schuster Volker 
Published: December 2010

SummaryInherited severe hypoplasminogenaemia is a multisystemic disorder leading to deficient extravascular fibrinolysis. As a clinical consequence wound healing capacity of mucous membranes is markedly impaired leading to ligneous conjunctivitis and several other manifestations. Here we report the molecular genetic and clinical findings on 23 new cases with severe hypoplasminogenaemia. Homozygous or compound-heterozygous mutations in the plasminogen (PLG) gene were found in 16 of 23 patients (70%), three of which were novel mutations reported here for the first time (C166Y, Y264S, IVS10–7T/G). Compared to 79 previously published cases, clinical manifestations of the current group of patients showed higher percentages of ligneous periodontitis, congenital hydrocephalus, and involvement of the female genital tract. In contrast, involvement of the gastrointestinal or urogenital tract was not observed in any of the cases. Patients originated to a large extent (61%) from Turkey and the Middle East, and showed a comparably frequent occurrence of consanguinity of affected families and a greater female to male ratio than was derived from previous reports in the literature. Individual treatment of ligneous conjunctivitis included topical plasminogen or heparin eye drops, topical or systemic fresh frozen plasma, and surgical removal of ligneous pseudomembranes, mostly with modest or transient efficacy. In conclusion, the present study underscores the broad range of clinical manifestations in PLG-deficient patients with a trend to regional differences. Transmission of genetic and clinical data to the recently established Plasminogen Deficiency Registry should help to determine the prevalence of the disease and to develop more efficient treatment strategies.