bluuebunny/crossref_metadata_2025 huggingface dataset:
Mating Pair Formation Homologue TraG Is a Variable Membrane Protein Essential for Contact-Independent Type IV Secretion of Chromosomal DNA by Neisseria gonorrhoeae
Authors: Kohler Petra L. , Chan Yolande A. , Hackett Kathleen T. , Turner Nicholas , Hamilton Holly L. , Cloud-Hansen Karen A. , Dillard Joseph P.
Published: February 2013

Neisseria gonorrhoeae
uses a type IV secretion system (T4SS) to secrete chromosomal DNA into the surrounding milieu. The DNA is effective in transforming gonococci in the population, and this mechanism of DNA donation may contribute to the high degree of genetic diversity in this species. Similar to other F-like T4SSs, the gonococcal T4SS requires a putative membrane protein, TraG, for DNA transfer. In F-plasmid and related systems, the homologous protein acts in pilus production, mating pair stabilization, and entry exclusion. We characterized the localization, membrane topology, and variation of TraG in
N. gonorrhoeae
. TraG was found to be an inner-membrane protein with one large periplasmic region and one large cytoplasmic region. Each gonococcal strain carried one of three different alleles of
traG
. Strains that carried the smallest allele of
traG
were found to lack the peptidoglycanase gene
atlA
but carried a peptidoglycan endopeptidase gene in place of
atlA
. The purified endopeptidase degraded gonococcal peptidoglycan
in vitro
, cutting the peptide cross-links. Although the other two
traG
alleles functioned for DNA secretion in strain MS11, the smallest
traG
did not support DNA secretion. Despite the requirement for a mating pair stabilization homologue, static coculture transformation experiments demonstrated that DNA transfer was nuclease sensitive and required active uptake by the recipient, thus demonstrating that transfer occurred by transformation and not conjugation. Together, these results demonstrate the TraG acts in a process of DNA export not specific to conjugation and that different forms of TraG affect what substrates can be transported.
Ultrastructural Analysis of the Rugose Cell Envelope of a Member of the Pasteurellaceae Family
Authors: Azari Fereshteh , Nyland Lori , Yu Chunxiao , Radermacher Michael , Mintz Keith P. , Ruiz Teresa
Published: February 2013

Bacterial membranes serve as selective environmental barriers and contain determinants required for bacterial colonization and survival. Cell envelopes of Gram-negative bacteria consist of an outer and an inner membrane separated by a periplasmic space. Most Gram-negative bacteria display a smooth outer surface (e.g.,
Enterobacteriaceae
), whereas members of the
Pasteurellaceae
and
Moraxellaceae
families show convoluted surfaces.
Aggregatibacter actinomycetemcomitans
, an oral pathogen representative of the
Pasteurellaceae
family, displays a convoluted membrane morphology. This phenotype is associated with the presence of morphogenesis protein C (MorC). Inactivation of the
morC
gene results in a smooth membrane appearance when visualized by two-dimensional (2D) electron microscopy. In this study, 3D electron microscopy and atomic force microscopy of whole-mount bacterial preparations as well as 3D electron microscopy of ultrathin sections of high-pressure frozen and freeze-substituted specimens were used to characterize the membranes of both wild-type and
morC
mutant strains of
A. actinomycetemcomitans
. Our results show that the mutant strain contains fewer convolutions than the wild-type bacterium, which exhibits a higher curvature of the outer membrane and a periplasmic space with 2-fold larger volume/area ratio than the mutant bacterium. The inner membrane of both strains has a smooth appearance and shows connections with the outer membrane, as revealed by visualization and segmentation of 3D tomograms. The present studies and the availability of genetically modified organisms with altered outer membrane morphology make
A. actinomycetemcomitans
a model organism for examining membrane remodeling and its implications in antibiotic resistance and virulence in the
Pasteurellaceae
and
Moraxellaceae
bacterial families.
Identification and Characterization ofRe-Citrate Synthase in Syntrophus aciditrophicus
Authors: Kim Marie , Le Huynh , McInerney Michael J. , Buckel Wolfgang
Published: February 2013

Glutamate is usually synthesized from acetyl coenzyme A (acetyl-CoA) via citrate, isocitrate, and 2-oxoglutarate. Genome analysis revealed that inSyntrophus aciditrophicus, the gene forSi-citrate synthase is lacking. An alternative pathway starting from the catabolic intermediate glutaconyl-CoA via 2-hydroxyglutarate could be excluded by genomic analysis. On the other hand, a putative gene (SYN_02536; NCBI gene accession no.CP000252.1) annotated as coding for isopropylmalate/citramalate/homocitrate synthase has been shown to share 49% deduced amino acid sequence identity with the gene encodingRe-citrate synthase ofClostridium kluyveri. We cloned and overexpressed this gene inEscherichia colitogether with the genes encoding the chaperone GroEL. The recombinant homotetrameric enzyme with a C-terminal Strep-tag (4 × 72,892 Da) was separated from GroEL on a Strep-Tactin column by incubation with ATP, K+, and Mg2+. The pureRe-citrate synthase used only acetyl-CoA and oxaloacetate as the substrates. As isolated, the enzyme contained stoichiometric amounts of Ca2+(0.9 Ca/73 kDa) but achieved higher specific activities in the presence of Mn2+(1.2 U/mg) or Co2+(2.0 U/mg). To determine the stereospecificity of the enzyme, [14C]citrate was enzymatically synthesized from oxaloacetate and [1-14C]acetyl-CoA; the subsequent cleavage bySi-citrate lyase yielded unlabeled acetate and labeled oxaloacetate, demonstrating that the enzyme is aRe-citrate synthase. The production ofRe-citrate synthase byS. aciditrophicusgrown axenically on crotonate was revealed by synthesis of [14C]citrate in a cell extract followed by stereochemical analysis. This result was supported by detection of transcripts of theRe-citrate synthase gene in axenic as well as in syntrophic cultures using quantitative reverse transcriptase PCR (qRT-PCR).
Effects of Acupuncture on the Outcome of in Vitro Fertilisation and Intracytoplasmic Sperm Injection in Women with Polycystic Ovarian Syndrome
Authors: Rashidi Batool Hossein , Tehrani Ensieh Shahrokh , Hamedani Navid Alhosseini , Pirzadeh Leila
Published: February 2013

Background

Different mechanisms have been described for the effects of acupuncture on fertility. Acupuncture may mediate neurotransmitter release, which results in the stimulation of gonadotrophin-releasing hormone secretion. The production of neurotransmitters such as endogenous opioids may also inhibit central nervous system outflow and biological stress response. Acupuncture may also stimulate blood flow to the uterus by inhibiting uterine central sympathetic nerve activity. Despite some evidence suggesting beneficial effects of acupuncture on in vitro fertilisation (IVF) success rates, recent clinical trials could not duplicate these effects, especially in patients who are infertile with polycystic ovarian syndrome (PCOS) who are undergoing IVF.

Methods

A total of 62 women with PCOS undergoing IVF/intracytoplasmic sperm injection (ICSI) at Shayamehr IVF Clinic in Tehran (Iran) participated in a randomised, controlled trial. Participants were randomly allocated to one of two groups: there were 31 women each in the acupuncture (group I) and control groups (group II). Acupuncture based on traditional Chinese medicine was performed in group I versus no adjunctive treatment in group II. All acupuncture procedures were performed in five sessions: start of downregulation, start of stimulation, 2 days before ovum pick-up, and immediately before and after embryo transfer. We measured the rate of oocytes in metaphase II, the fertilisation rate and the quality of embryos.

Results

Our results showed a statistically higher mean of good quality embryos in group I compared with group II (p=0.044). However, the mean number of metaphase II oocytes retrieved and fertilisation rate were similar between the two groups. We also could not find any significant differences among clinical, biochemical or ongoing pregnancy rates.

Conclusions

Acupuncture at an early stage of oocyte recruitment may have a beneficial effect on embryo quality. However, it seems to have no significant effect on other IVF/ICSI outcomes of women with PCOS.

Trial Registration Number

(IRCT ID: 201011275181N4)
Intrapleural fibrinolytic therapy (IPFT) in loculated pleural effusions—analysis of predictors for failure of therapy and bleeding: a cohort study
Authors: Abu-Daff Saleh , Maziak Donna E , Alshehab Derar , Threader Jennifer , Ivanovic Jelena , Deslaurier Valerie , Villeneuve Patrick-James , Gilbert Sebastian , Sundaresan Sudhir , Shamji Farid , Lougheed Colleen , Seely Jean M , Seely Andrew J E
Published: February 2013

Objectives

To assess risk factors associated with failure and bleeding in intrapleural fibrinolytic therapy (IPFT) for pleural effusions.

Design

Retrospective case series.

Setting

Two tertiary-care centres in North America.

Participants

We identified 237 cases that received IPFT for the treatment of pleural effusions.Data for 227 patients were compiled including demographics, investigations, radiological findings pretherapy and post-therapy and outcomes.

Intervention

Fibrinolytic therapy in the form of tissue plasminogen activator (t-PA) or streptokinase.

Primary and secondary outcomes

Success of therapy is defined as the presence of both clinical and radiological improvement leading to resolution. Failure was defined as persistence (ie, ineffective treatment) or complications requiring intervention from IPFT. Incidence of bleeding post-IPFT, identifying factors related to failure of therapy and bleeding.

Results

IPFT was used in 237 patients with pleural effusions; 163 with empyema/complicated parapneumonic effusions, 32 malignant effusions and 23 with haemothorax. Overall, resolution was achieved in 80% of our cases. Failure occurred in 46 (20%) cases. Multivariate analysis revealed that failure was associated with the presence of pleural thickening (>2 mm) on CT scan (p=0.0031, OR 3, 95% CI 1.46 to 6.57). Bleeding was not associated with any specific variable in our study (antiplatelet medications, p=0.08).

Conclusions

Pleural thickening on a CT scan was found to be associated with failure of IPFT.
Suicidal feelings in the twilight of life: a cross-sectional population-based study of 97-year-olds
Authors: Fässberg Madeleine Mellqvist , Östling Svante , Börjesson-Hanson Anne , Skoog Ingmar , Wærn Margda
Published: February 2013

Objective

To examine the occurrence of past month suicidal feelings in extreme old age. Further, to identify factors associated with such feelings.

Design

Cross-sectional population-based study.

Setting

Gothenburg, Sweden.

Participants

269 adults (197 women, 72 men) without dementia born in 1901–1909 who participated in a psychiatric examination.

Main outcome measures

Death thoughts and suicidal feelings. The latter were rated in accordance with the Paykel questions (life not worth living, death wishes, thoughts of taking own life, seriously considered taking own life, attempted suicide) during the past month.

Results

One quarter of the sample (26.7%) reported that they thought about their own death at least once a month. Past month thoughts that life was not worth living were acknowledged by 7.9% of the total sample, death wishes by 10.5% and thoughts of taking life by 3.8%. Few had serious thoughts of taking own life (0.8%) and none had attempted suicide. In all, 11.5% acknowledged some level of suicidal feelings. Most (77.4%) of those who reported such feelings fulfilled criteria for neither major nor minor depression. Neither poor perceived health nor disability (hearing, vision and motor function) was associated with suicidal feelings. Problematic sleep and deficient social contacts were also related to suicidal feelings after adjustment for depression.

Conclusions

Suicidal feelings may occur outside the context of depression and disability in this age group. Results can inform clinicians who care for persons who reach extreme old age.
A cross-sectional study on socioeconomic status and health-related quality of life among elderly Chinese
Authors: Ma Xiaoguang , McGhee Sarah M
Published: February 2013

Objectives

To examine the association between socioeconomic status (SES) and health-related quality of life (HRQOL) in a sample of elderly Chinese people in Hong Kong.

Study Design

Cross-sectional study.

Setting

18 elderly health centers in Hong Kong.

Participants

This study was based on a cohort aged 65 years or above who were enrolled in the Elderly Health Services from 1998 to 2005 in Hong Kong. Initially, 3324 individuals were randomly sampled from the baseline database. In the end, 2441 successful cases were obtained for the telephone survey. After excluding cases with missing SES or HRQOL information and the cases whose questionnaires were answered by their family members, 2347 individuals were included in the final analysis.

Results

Elderly Chinese with less subjective economic hardship reported much better self-rated health (SRH) (OR 1.57–4.70, all p<0.01)< and higher Medical Outcomes Study short form (SF)12 scores (β 2.56–10.26, all p<0.01) than those with economic hardship. Male individuals in the highest education and occupation subgroup reported better HRQOL comparing with the baseline subgroup (OR for SRH 1.91–3.26, p<0.01; β 2.63–4.96, p<0.05). Two economic indicators, income and expenditure, only showed significant positive associations with physical SF12 scores for men (β 2.91–5.42, all p<0.05). Housing tenure was associated with SRH (OR 1.34 for men and 1.27 for women, p<0.05) but not SF12 scores.

Conclusions

Economic hardship showed the strongest association with HRQOL among all SES indicators. Educational level, occupational level and economic indicators tended to associate with physical HRQOL only among elderly Chinese men. More attention should be placed on subjective SES indicators when investigating influences on HRQOL among elderly Chinese people.
Improvement in the quality of molecular analysis ofEGFRin non-small-cell lung cancer detected by three rounds of external quality assessment
Authors: Deans Zandra C , Bilbe Neil , O'Sullivan Brendan , Lazarou Lazarus P , de Castro David Gonzalez , Parry Suzanne , Dodson Andrew , Taniere Philippe , Clark Caroline , Butler Rachel
Published: February 2013

Background

The clinical need to determine the presence of epidermal growth factor receptor (EGFR) gene mutations in non-small-cell lung cancers (NSCLC) in order to make informed decisions for patient treatment has seen the widespread introduction of EGFR molecular testing in many laboratories. To ensure high-quality molecular testing and allow laboratories to externally measure the standard of the service, an external quality assessment (EQA) scheme was provided to assess the whole testing process.

Methods

Formalin-fixed paraffin-embedded NSCLC tumour sections were distributed to laboratories for routine EGFR molecular testing, and the genotyping accuracy, interpretation of the result and clerical accuracy of the report were independently assessed.

Results

Three rounds of assessment have identified many genotyping errors and have highlighted the need for external assessment and education in many testing laboratories. The main issues raised were the importance of accurate genotyping, including the use of common mutation nomenclature, clear unambiguous interpretation of the result, the impact of tumour sample assessment regarding amount of tumour being analysed and the heterogeneity of the sample on the molecular test result.

Conclusions

Improvements in all these areas were observed during the progression of the three EQA rounds, however, continuous unacceptably high genotyping error rates demonstrate the clear need for continual external assessment and education in this field.
Breast cancerdiagnosis in aresource poorenvironment through a collaborativemultidisciplinaryapproach: the Kenyan experience
Authors: Sayed Shahin , Moloo Zahir , Bird Peter , Wasike Ronald , Njoroge Wambui , Karanu Joseph , Nzioka Ancent , Sherman Omar , Prasad Satya , Mariwa Costa , Otieno James Obondi , Chumba David , Koech David , Mbinga Daniel , Mohammed Musa , Njoroge Richard , Chauhan Rajendra , Vinayak Sudhir , Kyobutungi Catherine , Saleh Mansoor
Published: February 2013

INTRODUCTION

The majority of women with breast cancer in Kenya present with node-positive (stage II) or locally advanced Q7 disease (stage IIIB). Diagnosis is made on fine needle aspirate cytology and treatment is with surgery if resectable. Diagnostic core biopsy is available only at subspecialty hospitals. Processing and reporting of biopsy tissue are not standardised. Hormone receptor and HER2 analyses are rarely done preoperatively.

METHODS

As part of a larger study investigating the prevalence of triple negative breast cancer in Kenya, a multidisciplinary workshop of collaborators from 10 healthcare facilities was held. Process gaps were identified, preanalytic variables impacting on ER/PR/HER2 discussed and training in core biopsy provided. Local remedial strategies were deliberated.

CONCLUSION

We describe our experience and outcome from the workshop, which can be modelled for other resource poor settings.
An investigation of the cost and benefit of mechanical thrombectomy for endovascular treatment of acute ischemic stroke
Authors: Turk Aquilla S , Campbell John M , Spiotta Alejandro , Vargas Jan , Turner Raymond D , Chaudry M Imran , Battenhouse Holly , Holmstedt Christine A , Jauch Edward
Published: February 2013

Introduction

The use of mechanical thrombectomy for the treatment of acute ischemic stroke has significantly advanced over the past 5 years, with few available data. The aim of this study was to analyze the cost and benefit of mechanical thrombectomy devices utilized during endovascular therapy of ischemic stroke patients.

Methods

A retrospective chart review of patients that underwent intra-arterial stroke interventions was conducted. Clinical, angiographic, all devices used, procedural and postprocedural event and outcome data were collected. Thrombectomy devices were categorized as Penumbra aspiration system thrombectomy (group P) or stent retriever (group S). Statistical analysis of outcomes and costs for each group was performed.

Results

171 patients underwent mechanical thrombectomy. The Penumbra aspiration system was able to primarily achieve recanalization in 41.7% and the stent retriever in 70.4% of the time (p=0.006). The average cost was $11 159 and $16 022 (p=0.0002) in groups P and S, respectively. Average time to recanalization for group P was 85.1 min and for group S, 51.6 min (p<0.0001). Procedural complications were more frequent with the stent retriever (11.1% vs 9.0%; p=0.72) as were periprocedural significant complications (14.8 v 3%; p=0.04). Successful recanalization rates (Thrombolysis in Cerebral Infarction score 2b-3) were the same in groups P and S (78.5 vs. 77.8%). Similar rates of good neurologic outcomes were seen in group P (36.4%) and group S (50.0%) (p=0.19).

Conclusions

For the treatment of acute stroke patients, the use of aspiration appears to be the most cost effective method to achieve acceptable recanalization rates and low complication rates. Stent retriever with local aspiration, despite higher costs and complication rates, yielded better overall outcome.
Systemic Acquired Resistance: Turning Local Infection into Global Defense
Authors: Fu Zheng Qing , Dong Xinnian
Published: February 2013

Systemic acquired resistance (SAR) is an induced immune mechanism in plants. Unlike vertebrate adaptive immunity, SAR is broad spectrum, with no specificity to the initial infection. An avirulent pathogen causing local programmed cell death can induce SAR through generation of mobile signals, accumulation of the defense hormone salicylic acid, and secretion of the antimicrobial PR (pathogenesis-related) proteins. Consequently, the rest of the plant is protected from secondary infection for a period of weeks to months. SAR can even be passed on to progeny through epigenetic regulation. The Arabidopsis NPR1 (nonexpresser of PR genes 1) protein is a master regulator of SAR. Recent study has shown that salicylic acid directly binds to the NPR1 adaptor proteins NPR3 and NPR4, regulates their interactions with NPR1, and controls NPR1 protein stability. However, how NPR1 interacts with TGA transcription factors to activate defense gene expression is still not well understood. In addition, redox regulators, the mediator complex, WRKY transcription factors, endoplasmic reticulum–resident proteins, and DNA repair proteins play critical roles in SAR.
Photoreceptor Signaling Networks in Plant Responses to Shade
Authors: Casal Jorge J.
Published: February 2013

The dynamic light environment of vegetation canopies is perceived by phytochromes, cryptochromes, phototropins, and UV RESISTANCE LOCUS 8 (UVR8). These receptors control avoidance responses to preclude exposure to limiting or excessive light and acclimation responses to cope with conditions that cannot be avoided. The low red/far-red ratios of shade light reduce phytochrome B activity, which allows PHYTOCHROME INTERACTING FACTORS (PIFs) to directly activate the transcription of auxin-synthesis genes, leading to shade-avoidance responses. Direct PIF interaction with DELLA proteins links gibberellin and brassinosteroid signaling to shade avoidance. Shade avoidance also requires CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1), a target of cryptochromes, phytochromes, and UVR8. Multiple regulatory loops and the input of the circadian clock create a complex network able to respond even to subtle threats of competition with neighbors while still compensating for major environmental fluctuations such as the day-night cycles.
Role of impaired endothelial cell Ca2+signaling in uteroplacental vascular dysfunction during diabetic rat pregnancy
Authors: Gokina Natalia I. , Bonev Adrian D. , Gokin Alexander P. , Goloman Gabriela
Published: February 2013

Diabetes mellitus in pregnancy is associated with impaired endothelium-mediated dilatation of maternal arteries, although the underlying cellular mechanisms remain unknown. In this study, we hypothesized that diabetes during rat gestation attenuates agonist-induced uterine vasodilation through reduced endothelial cell (EC) Ca2+elevations and impaired smooth muscle cell (SMC) hyperpolarization and SMC intracellular Ca2+concentration ([Ca2+]i) responses. Diabetes was induced by an injection of streptozotocin to second-day pregnant rats and confirmed by the development of maternal hyperglycemia. Control rats were injected with a citrate buffer. Fura-2-based measurements of SMC [Ca2+]ior microelectrode recordings of SMC membrane potential were performed concurrently with dilator responses to ACh in uteroplacental arteries from control and diabetic pregnant rats. Basal levels of EC [Ca2+]iand ACh-induced EC [Ca2+]ielevations in pressurized vessels and small EC sheets were studied as well. Diabetes reduced ACh-induced vasodilation due to a markedly impaired EDHF-mediated response. Diminished vasodilation to ACh was associated with attenuated SMC hyperpolarization and [Ca2+]iresponses. Basal levels of EC [Ca2+]iand ACh-induced EC [Ca2+]ielevations were significantly reduced by diabetes. In conclusion, these data demonstrate that reduced endothelium-mediated hyperpolarization contributes to attenuated uteroplacental vasodilation and SMC [Ca2+]iresponses to ACh in diabetic pregnancy. Impaired endothelial Ca2+signaling is in part responsible for endothelial dysfunction in the uterine resistance vasculature of diabetic rats. Pharmacological improvement of EC Ca2+handling may provide an important strategy for the restoration of endothelial function and enhancement of maternal blood flow in human pregnancies complicated by diabetes.
Effects of mitochondrial uncoupling on Ca2+signaling during excitation-contraction coupling in atrial myocytes
Authors: Zima Aleksey V. , Pabbidi Malikarjuna R. , Lipsius Stephen L. , Blatter Lothar A.
Published: February 2013

Mitochondria play an important role in intracellular Ca2+concentration ([Ca2+]i) regulation in the heart. We studied sarcoplasmic reticulum (SR) Ca2+release in cat atrial myocytes during depolarization of mitochondrial membrane potential (ΔΨm) induced by the protonophore FCCP. FCCP caused an initial decrease of action potential-induced Ca2+transient amplitude and frequency of spontaneous Ca2+waves followed by partial recovery despite partially depleted SR Ca2+stores. In the presence of oligomycin, FCCP only exerted a stimulatory effect on Ca2+transients and Ca2+wave frequency, suggesting that the inhibitory effect of FCCP was mediated by ATP consumption through reverse-mode operation of mitochondrial F1F0-ATPase. ΔΨmdepolarization was accompanied by cytosolic acidification, increases of diastolic [Ca2+]i, intracellular Na+concentration ([Na+]i), and intracellular Mg2+concentration ([Mg2+]i), and a decrease of intracellular ATP concentration ([ATP]i); however, glycolytic ATP production partially compensated for the exhaustion of mitochondrial ATP supplies. In conclusion, the initial inhibition of Ca2+transients and waves resulted from suppression of ryanodine receptor SR Ca2+release channel activity by a decrease in [ATP], an increase of [Mg2+]i, and cytoplasmic acidification. The later stimulation resulted from reduced mitochondrial Ca2+buffering and cytosolic Na+and Ca2+accumulation, leading to enhanced Ca2+-induced Ca2+release and spontaneous Ca2+release in the form of Ca2+waves. ΔΨmdepolarization and the ensuing consequences of mitochondrial uncoupling observed here (intracellular acidification, decrease of [ATP]i, increase of [Na+]iand [Mg2+]i, and Ca2+overload) are hallmarks of ischemia. These findings may therefore provide insight into the consequences of mitochondrial uncoupling for ion homeostasis, SR Ca2+release, and excitation-contraction coupling in ischemia at the cellular and subcellular level.
The role of hypoxia in pulmonary vascular diseases: a perspective
Authors: Voelkel Norbert F. , Mizuno Shiro , Bogaard Harm J.
Published: February 2013

From the discovery of hypoxic pulmonary vasoconstriction, responses to hypoxia have been considered as representative for the many alterations in lung vessels that occur in several chronic lung diseases, including pulmonary hypertension, interstitial pulmonary fibrosis, acute respiratory distress syndrome, and chronic obstructive pulmonary disease. An essential part of preclinical research to explain the pathobiology of these diseases has been centered on the exposure of small and large animals to hypoxia. This review aims to summarize pivotal results of clinical and preclinical research on hypoxia, which still have important implications for researchers today.
Macrophage TNF-α mediates parathion-induced airway hyperreactivity in guinea pigs
Authors: Proskocil Becky J. , Bruun Donald A. , Jacoby David B. , van Rooijen Nico , Lein Pamela J. , Fryer Allison D.
Published: February 2013

Organophosphorus pesticides (OPs) are implicated in human asthma. We previously demonstrated that, at concentrations that do not inhibit acetylcholinesterase activity, the OP parathion causes airway hyperreactivity in guinea pigs as a result of functional loss of inhibitory M2 muscarinic receptors on parasympathetic nerves. Because macrophages are associated with asthma, we investigated whether macrophages mediate parathion-induced M2 receptor dysfunction and airway hyperreactivity. Airway physiology was measured in guinea pigs 24 h after a subcutaneous injection of parathion. Pretreatment with liposome-encapsulated clodronate induced alveolar macrophage apoptosis and prevented parathion-induced airway hyperreactivity in response to electrical stimulation of the vagus nerves. As determined by qPCR, TNF-α and IL-1β mRNA levels were increased in alveolar macrophages isolated from parathion-treated guinea pigs. Parathion treatment of alveolar macrophages ex vivo did not significantly increase IL-1β and TNF-α mRNA but did significantly increase TNF-α protein release. Consistent with these data, pretreatment with the TNF-α inhibitor etanercept but not the IL-1β receptor inhibitor anakinra prevented parathion-induced airway hyperreactivity and protected M2 receptor function. These data suggest a novel mechanism of OP-induced airway hyperreactivity in which low-level parathion activates macrophages to release TNF-α-causing M2 receptor dysfunction and airway hyperreactivity. These observations have important implications regarding therapeutic approaches for treating respiratory disease associated with OP exposures.
Magnetic Field Effect on Natural Convection in a Porous Cavity Heating from below and Salting from Side
Authors: Altawallbeh A. A. , Saeid N. H. , Hashim I.
Published: February 2013

The effect of magnetic field on double-diffusive natural convection in a square cavity filled with a fluid-saturated porous medium is studied numerically. The bottom wall is fully heated at a constant temperature, and the top wall is maintained at a constant cold temperature. The right wall is fully salted to a high concentration, while the left wall is fully salted at a lower concentration than the right one. A magnetic force is applied on the cavity along the gravity force direction. The Darcy model is used for the mathematical formulation of the fluid flow through porous media. The governing equations for heat and mass transfer are solved using the finite volume method. The governing parameters of the present study are Rayleigh number (Ra), Lewis number (Le), buoyancy ratio ( N), and Hartmann number (Ha). The numerical solutions were studied in the range of −10 ≤ N ≤ 10, 0 ≤ Ha ≤ 10, 50 ≤ Ra ≤ 500, and 10−4 ≤ Le ≤ 10. The results were discussed considering the effect of these parameters on the heat and mass transfer processes. The results were presented in terms of streamlines, isotherms, isoconcentration, average Nusselt number, and average Sherwood number for different values of the governing parameters. In general, it has been found that the increase of magnetic force has an effect to retard the strength of the flow inside the cavity and reduce the heat and mass transfer processes. For high Hartmann number, the flow is almost suppressed.
Evidence for Stable High-Temperature Ferromagnetism in Fluorine-Treated C60
Authors: Patel Rajen , Owens Frank J.
Published: February 2013

It is shown by magnetic field dependent ac susceptibility, magnetic force microscopy, and ferromagnetic resonance that exposure of C60 to fluorine at
160°C produces a stable ferromagnetic material with a Curie temperature well above room temperature. The exposure to fluorine is accomplished by decomposing a fluorine-rich polymer, trifluorochloroethylene [F2C–CFCl]n, which has C60 imbedded in it. Based on previous experimental observations and molecular orbital calculations, it is suggested that the ferromagnetism is arising from crystals of C60–F.
Random Forest in Clinical Metabolomics for Phenotypic Discrimination and Biomarker Selection
Authors: Chen Tianlu , Cao Yu , Zhang Yinan , Liu Jiajian , Bao Yuqian , Wang Congrong , Jia Weiping , Zhao Aihua
Published: February 2013

Metabolomic data analysis becomes increasingly challenging when dealing with clinical samples with diverse demographic and genetic backgrounds and various pathological conditions or treatments. Although many classification tools, such as projection to latent structures (PLS), support vector machine (SVM), linear discriminant analysis (LDA), and random forest (RF), have been successfully used in metabolomics, their performance including strengths and limitations in clinical data analysis has not been clear to researchers due to the lack of systematic evaluation of these tools. In this paper we comparatively evaluated the four classifiers, PLS, SVM, LDA, and RF, in the analysis of clinical metabolomic data derived from gas chromatography mass spectrometry platform of healthy subjects and patients diagnosed with colorectal cancer, where cross-validation,R2/Q2plot, receiver operating characteristic curve, variable reduction, and Pearson correlation were performed. RF outperforms the other three classifiers in the given clinical data sets, highlighting its comparative advantages as a suitable classification and biomarker selection tool for clinical metabolomic data analysis.
Clinical Factors Influencing Phenotype of HCMV-Specific CD8+ T Cells and HCMV-Induced Interferon-Gamma Production after Allogeneic Stem Cells Transplantation
Authors: Gayoso Inmaculada , Cantisán Sara , Cerrato Carolina , Sánchez-García Joaquín , Martin Carmen , Solana Rafael , Torres-Gomez Antonio , Torre-Cisneros Julian
Published: February 2013

Human cytomegalovirus (HCMV) infection causes significant morbidity and mortality after hematopoietic stem cell transplantation (HSCT). In this work, we characterized the phenotype and interferon-gamma (INF-γ) production of HCMV-specific T cells using QuantiFERON-HCMV assay in 26 patients 6 months after HSCT. We analysed whether these two parameters were associated with clinical variables. Our results showed that the patients receiving stem cells from donors ≥40 years old were 12 times more likely to have HCMV-specific CD8+ T cells with “differentiated phenotype” (CD45RA+CCR7+ ≤6.7% and CD28+ ≤30%) than patients grafted from donors <40 years old (OR=12;P=0.014). In addition, a detectable IFN-γproduction in response to HCMV peptides (cutoff 0.2 IU/mL IFN-γ; “reactive” QuantiFERON-HCMV test) was statistically associated with HCMV replication after transplantation (OR=11;P=0.026), recipients ≥40 versus <40 years old (OR=11;P=0.026), and the use of peripheral blood versus bone marrow as stem cell source (OR=17.5;P=0.024). In conclusion, donor age is the only factor significantly associated with the presence of the “differentiated phenotype” in HCMV-specific CD8+ T cells, whereas HCMV replication after transplantation, recipient age, and stem cell source are the factors associated with the production of IFN-γin response to HCMV epitopes.
Obtaining of Sol‐Gel Ketorolac‐Silica Nanoparticles: Characterization and Drug Release Kinetics
Authors: López Goerne T. M. , López García M. G. , Rodríguez Grada G. , Ortiz Pérez I. , Gómez López E. , Alvarez Lemus M. A.
Published: February 2013

Nonsteroidal anti‐inflammatory drugs (NSAIDs) are among most commonly prescribed medications worldwide. NSAIDs play an important role due to their pronounced analgesic potency, anti‐inflammatory effects, and lesser side effects compared to opioids. However, adverse effects including gastrointestinal and cardiovascular effects seriously complicate their prolonged use. In the present work we prepare SiO2‐based nanoparticles with ketorolac, for controlled release proposes. The nanomaterials were prepared by the sol‐gel technology at acidic conditions and two different water/alcoxide ratios were used. FTIR spectroscopy was performed in order to characterize the solids and drug‐SiO2 interactions. Thermal analysis and nitrogen adsorption isotherms showed thermal stability of the drug and confirmed the presence of particles with high surface area. Transmission electron micrographies of the samples showed the nanosize particles (20 nm) forming aggregates. Drug release profiles were collected by means of UV‐Vis spectroscopy and kinetic analysis was developed. Release data were fitted and 1 : 8 sample showed a sustained release over ten hours; 90% of the drug was delivered at the end of the time.
RF Magnetron Sputtering Aluminum Oxide Film for Surface Passivation on Crystalline Silicon Wafers
Authors: Chen Siming , Tao Luping , Zeng Libin , Hong Ruijiang
Published: February 2013

Aluminum oxide films were deposited on crystalline silicon substrates by reactive RF magnetron sputtering. The influences of the deposition parameters on the surface passivation, surface damage, optical properties, and composition of the films have been investigated. It is found that proper sputtering power and uniform magnetic field reduced the surface damage from the high-energy ion bombardment to the silicon wafers during the process and consequently decreased the interface trap density, resulting in the good surface passivation; relatively high refractive index of aluminum oxide film is benefic to improve the surface passivation. The negative-charged aluminum oxide film was then successfully prepared. The surface passivation performance was further improved after postannealing by formation of an SiOxinterfacial layer. It is demonstrated that the reactive sputtering is an effective technique of fabricating aluminum oxide surface passivation film for low-cost high-efficiency crystalline silicon solar cells.
Employment Precariousness and Poor Mental Health: Evidence from Spain on a New Social Determinant of Health
Authors: Vives Alejandra , Amable Marcelo , Ferrer Montserrat , Moncada Salvador , Llorens Clara , Muntaner Carles , Benavides Fernando G. , Benach Joan
Published: February 2013

Background.Evidence on the health-damaging effects of precarious employment is limited by the use of one-dimensional approaches focused on employment instability. This study assesses the association between precarious employment and poor mental health using the multidimensional Employment Precariousness Scale.Methods.Cross-sectional study of 5679 temporary and permanent workers from the population-based Psychosocial Factors Survey was carried out in 2004-2005 in Spain. Poor mental health was defined as SF-36 mental health scores below the 25th percentile of the Spanish reference for each respondent’s sex and age. Prevalence proportion ratios (PPRs) of poor mental health across quintiles of employment precariousness (reference: 1st quintile) were calculated with log-binomial regressions, separately for women and men.Results.Crude PPRs showed a gradient association with poor mental health and remained generally unchanged after adjustments for age, immigrant status, socioeconomic position, and previous unemployment. Fully adjusted PPRs for the 5th quintile were 2.54 (95% CI: 1.95–3.31) for women and 2.23 (95% CI: 1.86–2.68) for men.Conclusion.The study finds a gradient association between employment precariousness and poor mental health, which was somewhat stronger among women, suggesting an interaction with gender-related power asymmetries. Further research is needed to strengthen the epidemiological evidence base and to inform labour market policy-making.
Plastin3 Is a Novel Marker for Circulating Tumor Cells Undergoing the Epithelial–Mesenchymal Transition and Is Associated with Colorectal Cancer Prognosis
Authors: Yokobori Takehiko , Iinuma Hisae , Shimamura Teppei , Imoto Seiya , Sugimachi Keishi , Ishii Hideshi , Iwatsuki Masaaki , Ota Daisuke , Ohkuma Masahisa , Iwaya Takeshi , Nishida Naohiro , Kogo Ryunosuke , Sudo Tomoya , Tanaka Fumiaki , Shibata Kohei , Toh Hiroyuki , Sato Tetsuya , Barnard Graham F. , Fukagawa Takeo , Yamamoto Seiichiro , Nakanishi Hayao , Sasaki Shin , Miyano Satoru , Watanabe Toshiaki , Kuwano Hiroyuki , Mimori Koshi , Pantel Klaus , Mori Masaki
Published: February 2013

Circulating tumor cells (CTC) in blood have attracted attention both as potential seeds for metastasis and as biomarkers. However, most CTC detection systems might miss epithelial–mesenchymal transition (EMT)-induced metastatic cells because detection is based on epithelial markers. First, to discover novel markers capable of detecting CTCs in which EMT has not been repressed, microarray analysis of 132 colorectal cancers (CRC) from Japanese patients was conducted, and 2,969 genes were detected that were overexpressed relative to normal colon mucosa. From the detected genes, we selected those that were overexpressed CRC with distant metastasis. Then, we analyzed the CRC metastasis-specific genes (n = 22) to determine whether they were expressed in normal circulation. As a result, PLS3 was discovered as a CTC marker that was expressed in metastatic CRC cells but not in normal circulation. Using fluorescent immunocytochemistry, we validated that PLS3 was expressed in EMT-induced CTC in peripheral blood from patients with CRC with distant metastasis. PLS3-expressing cells were detected in the peripheral blood of approximately one-third of an independent set of 711 Japanese patients with CRC. Multivariate analysis showed that PLS3-positive CTC was independently associated with prognosis in the training set (n = 381) and the validation set [n = 330; HR = 2.17; 95% confidence interval (CI) = 1.38–3.40 and HR = 3.92; 95% CI = 2.27–6.85]. The association between PLS3-positive CTC and prognosis was particularly strong in patients with Dukes B (HR = 4.07; 95% CI = 1.50–11.57) and Dukes C (HR = 2.57; 95% CI = 1.42–4.63). PLS3 is a novel marker for metastatic CRC cells, and it possesses significant prognostic value. Cancer Res; 73(7); 2059–69. ©2012 AACR.
Cholesterol Loading and Ultrastable Protein Interactions Determine the Level of Tumor Marker Required for Optimal Isolation of Cancer Cells
Authors: Jain Jayati , Veggiani Gianluca , Howarth Mark
Published: February 2013

Cell isolation via antibody-targeted magnetic beads is a powerful tool for research and clinical applications, most recently for isolating circulating tumor cells (CTC). Nonetheless fundamental features of the cell–bead interface are still unknown. Here we apply a clinically relevant antibody against the cancer target HER2 (ErbB2) for magnetic cell isolation. We investigate how many target proteins per cell are sufficient for a cell to be isolated. To understand the importance of primary antibody affinity, we compared a series of point mutants with known affinities and show that even starting with subnanomolar affinity, improving antibody affinity improved cell isolation. To test the importance of the connection between the primary antibody and the magnetic bead, we compared bridging the antibody to the beads with Protein L, secondary antibody, or streptavidin: the high-stability streptavidin–biotin linkage improved sensitivity by an order of magnitude. Cytoskeletal polymerization did not have a major effect on cell isolation, but isolation was inhibited by cholesterol depletion and enhanced by cholesterol loading of cells. Analyzing a panel of human cancer cell lines spanning a wide range of expression showed that the standard approach could only isolate the highest expressing cells. However, our optimization of cholesterol level, primary antibody affinity, and antibody–bead linkage allowed efficient and specific isolation of cells expressing low levels of HER2 or epithelial cell adhesion molecule. These insights should guide future approaches to cell isolation, either magnetically or using other means, and extend the range of cellular antigens and biomarkers that can be targeted for CTC isolation in cancer research and diagnosis. Cancer Res; 73(7); 2310–21. ©2013 AACR.
FOXO3a Is a Major Target of Inactivation by PI3K/AKT Signaling in Aggressive Neuroblastoma
Authors: Santo Evan E. , Stroeken Peter , Sluis Peter V. , Koster Jan , Versteeg Rogier , Westerhout Ellen M.
Published: February 2013

Neuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have not been determined. Here we identify the forkhead transcription factor FOXO3a as a key target of the PI3K/AKT pathway in neuroblastoma. FOXO3a expression was elevated in low-stage neuroblastoma tumors and normal embryonal neuroblasts, but reduced in late-stage neuroblastoma. Inactivation of FOXO3a by AKT was essential for neuroblastoma cell survival. Treatment of neuroblastoma cells with the dual PI3K/mTOR inhibitor PI-103 activated FOXO3a and triggered apoptosis. This effect was rescued by FOXO3a silencing. Conversely, apoptosis induced by PI-103 or the AKT inhibitor MK-2206 was potentiated by FOXO3a overexpression. Furthermore, levels of total or phosphorylated FOXO3a correlated closely with apoptotic sensitivity to MK-2206. In clinical specimens, there was an inverse relationship between gene expression signatures regulated by PI3K signaling and FOXO3a transcriptional activity. Moreover, high PI3K activity and low FOXO3a activity were each associated with an extremely poor prognosis. Our work indicates that expression of FOXO3a and its targets offer useful prognostic markers as well as biomarkers for PI3K/AKT inhibitor efficacy in neuroblastoma. Cancer Res; 73(7); 2189–98. ©2013 AACR.
Autoimmune Gastritis Mediated by CD4+ T Cells Promotes the Development of Gastric Cancer
Authors: Nguyen Thanh-Long M. , Khurana Shradha S. , Bellone Clifford J. , Capoccia Benjamin J. , Sagartz John E. , Kesman Russell A. , Mills Jason C. , DiPaolo Richard J.
Published: February 2013

Chronic inflammation is a major risk factor for cancer, including gastric cancers and other gastrointestinal cancers. For example, chronic inflammation caused by autoimmune gastritis (AIG) is associated with an increased risk of gastric polyps, gastric carcinoid tumors, and possibly adenocarcinomas. In this study, we characterized the progression of gastric cancer in a novel mouse model of AIG. In this model, disease was caused by CD4+ T cells expressing a transgenic T-cell receptor specific for a peptide from the H+/K+ ATPase proton pump, a protein expressed by parietal cells in the stomach. AIG caused epithelial cell aberrations that mimicked most of those seen in progression of human gastric cancers, including chronic gastritis followed by oxyntic atrophy, mucous neck cell hyperplasia, spasmolytic polypeptide-expressing metaplasia, dysplasia, and ultimately gastric intraepithelial neoplasias. Our work provides the first direct evidence that AIG supports the development of gastric neoplasia and provides a useful model to study how inflammation drives gastric cancer. Cancer Res; 73(7); 2117–26. ©2013 AACR.