bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Gene Expression during the Onset of Ligninolytic Oxidation by Phanerochaete chrysosporium on Spruce Wood
Authors: Korripally Premsagar , Hunt Christopher G. , Houtman Carl J. , Jones Don C. , Kitin Peter J. , Cullen Dan , Hammel Kenneth E.
Published: September 2015

Since uncertainty remains about how white rot fungi oxidize and degrade lignin in wood, it would be useful to monitor changes in fungal gene expression during the onset of ligninolysis on a natural substrate. We grew
Phanerochaete chrysosporium
on solid spruce wood and included oxidant-sensing beads bearing the fluorometric dye BODIPY 581/591 in the cultures. Confocal fluorescence microscopy of the beads showed that extracellular oxidation commenced 2 to 3 days after inoculation, coincident with cessation of fungal growth. Whole transcriptome shotgun sequencing (RNA-seq) analyses based on the v.2.2
P. chrysosporium
genome identified 356 genes whose transcripts accumulated to relatively high levels at 96 h and were at least four times the levels found at 40 h. Transcripts encoding some lignin peroxidases, manganese peroxidases, and auxiliary enzymes thought to support their activity showed marked apparent upregulation. The data were also consistent with the production of ligninolytic extracellular reactive oxygen species by the action of manganese peroxidase-catalyzed lipid peroxidation, cellobiose dehydrogenase-catalyzed Fe
3+
reduction, and oxidase-catalyzed H
2
O
2
production, but the data do not support a role for iron-chelating glycopeptides. In addition, transcripts encoding a variety of proteins with possible roles in lignin fragment uptake and processing, including 27 likely transporters and 18 cytochrome P450s, became more abundant after the onset of extracellular oxidation. Genes encoding cellulases showed little apparent upregulation and thus may be expressed constitutively. Transcripts corresponding to 165 genes of unknown function accumulated more than 4-fold after oxidation commenced, and some of them may merit investigation as possible contributors to ligninolysis.
Single-Domain Peptidyl-Prolyl
cis
/
trans
Isomerase FkpA from Corynebacterium glutamicum Improves the Biomass Yield at Increased Growth Temperatures
Authors: Kallscheuer Nicolai , Bott Michael , van Ooyen Jan , Polen Tino
Published: September 2015

Peptidyl-prolyl
cis
/
trans
isomerases (PPIases) catalyze the rate-limiting protein folding step at peptidyl bonds preceding proline residues and were found to be involved in several biological processes, including gene expression, signal transduction, and protein secretion. Representative enzymes were found in almost all sequenced genomes, including
Corynebacterium glutamicum
, a facultative anaerobic Gram-positive and industrial workhorse for the production of amino acids. In
C. glutamicum
, a predicted single-domain FK-506 (tacrolimus) binding protein (FKBP)-type PPIase (FkpA) is encoded directly downstream of
gltA
, which encodes citrate synthase (CS). This gene cluster is also present in other
Actinobacteria
. Here we carried out
in vitro
and
in vivo
experiments to study the function and influence of predicted FkpA in
C. glutamicum
.
In vitro
, FkpA indeed shows typical PPIase activity with artificial substrates and is inhibited by FK-506. Furthermore, FkpA delays the aggregation of CS, which is also inhibited by FK-506. Surprisingly, FkpA has a positive effect on the activity and temperature range of CS
in vitro
. Deletion of
fkpA
causes a 50% reduced biomass yield compared to that of the wild type when grown at 37°C, whereas there is only a 10% reduced biomass yield at the optimal growth temperature of 30°C accompanied by accumulation of 7 mM
l
-glutamate and 22 mM 2-oxoglutarate. Thus, FkpA may be exploited for improved product formation in biotechnical processes. Comparative transcriptome analysis revealed 69 genes which exhibit ≥2-fold mRNA level changes in
C. glutamicum
Δ
fkpA
, giving insight into the transcriptional response upon mild heat stress when FkpA is absent.
Control of Gene Expression in Leptospira spp. by Transcription Activator-Like Effectors Demonstrates a Potential Role for LigA and LigB in Leptospira interrogans Virulence
Authors: Pappas Christopher J. , Picardeau Mathieu
Published: September 2015

Leptospirosis is a zoonotic disease that affects ∼1 million people annually, with a mortality rate of >10%. Currently, there is an absence of effective genetic manipulation tools for targeted mutagenesis in pathogenic leptospires. Transcription activator-like effectors (TALEs) are a recently described group of repressors that modify transcriptional activity in prokaryotic and eukaryotic cells by directly binding to a targeted sequence within the host genome. To determine the applicability of TALEs within
Leptospira
spp., two TALE constructs were designed. First, a constitutively expressed TALE gene specific for the
lacO
-like region upstream of
bgaL
was
trans
inserted in the saprophyte
Leptospira biflexa
(the TALE
βgal
strain). Reverse transcriptase PCR (RT-PCR) analysis and enzymatic assays demonstrated that BgaL was not expressed in the TALE
βgal
strain. Second, to study the role of LigA and LigB in pathogenesis, a constitutively expressed TALE gene with specificity for the homologous promoter regions of
ligA
and
ligB
was
cis
inserted into the pathogen
Leptospira interrogans
(TALE

lig

). LigA and LigB expression was studied by using three independent clones: TALE

lig1

, TALE

lig2

, and TALE

lig3

. Immunoblot analysis of osmotically induced TALE

lig

clones demonstrated 2- to 9-fold reductions in the expression levels of LigA and LigB, with the highest reductions being noted for TALE

lig1

and TALE

lig2

, which were avirulent
in vivo
and nonrecoverable from animal tissues. This study reconfirms galactosidase activity in the saprophyte and suggests a role for LigA and LigB in pathogenesis. Collectively, this study demonstrates that TALEs are effective at reducing the expression of targeted genes within saprophytic and pathogenic strains of
Leptospira
spp., providing an additional genetic manipulation tool for this genus.
The Cytosolic pH of Individual Saccharomyces cerevisiae Cells Is a Key Factor in Acetic Acid Tolerance
Authors: Fernández-Niño Miguel , Marquina Maribel , Swinnen Steve , Rodríguez-Porrata Boris , Nevoigt Elke , Ariño Joaquín
Published: September 2015

It was shown recently that individual cells of an isogenic
Saccharomyces cerevisiae
population show variability in acetic acid tolerance, and this variability affects the quantitative manifestation of the trait at the population level. In the current study, we investigated whether cell-to-cell variability in acetic acid tolerance could be explained by the observed differences in the cytosolic pHs of individual cells immediately before exposure to the acid. Results obtained with cells of the strain CEN.PK113-7D in synthetic medium containing 96 mM acetic acid (pH 4.5) showed a direct correlation between the initial cytosolic pH and the cytosolic pH drop after exposure to the acid. Moreover, only cells with a low initial cytosolic pH, which experienced a less severe drop in cytosolic pH, were able to proliferate. A similar correlation between initial cytosolic pH and cytosolic pH drop was also observed in the more acid-tolerant strain MUCL 11987-9. Interestingly, a fraction of cells in the MUCL 11987-9 population showed initial cytosolic pH values below the minimal cytosolic pH detected in cells of the strain CEN.PK113-7D; consequently, these cells experienced less severe drops in cytosolic pH. Although this might explain in part the difference between the two strains with regard to the number of cells that resumed proliferation, it was observed that all cells from strain MUCL 11987-9 were able to proliferate, independently of their initial cytosolic pH. Therefore, other factors must also be involved in the greater ability of MUCL 11987-9 cells to endure strong drops in cytosolic pH.
Abundance of Antibiotic Resistance Genes in Bacteriophage following Soil Fertilization with Dairy Manure or Municipal Biosolids, and Evidence for Potential Transduction
Authors: Ross Joseph , Topp Edward
Published: September 2015

Animal manures and municipal biosolids recycled onto crop production land carry antibiotic-resistant bacteria that can influence the antibiotic resistome of agricultural soils, but little is known about the contribution of bacteriophage to the dissemination of antibiotic resistance genes (ARGs) in this context. In this work, we quantified a set of ARGs in the bacterial and bacteriophage fractions of agricultural soil by quantitative PCR. All tested ARGs were present in both the bacterial and phage fractions. We demonstrate that fertilization of soil with dairy manure or human biosolids increases ARG abundance in the bacterial fraction but not the bacteriophage fraction and further show that pretreatment of dairy manure can impact ARG abundance in the bacterial fraction. Finally, we show that purified bacteriophage can confer increased antibiotic resistance to soil bacteria when combined with selective pressure. The results indicate that soilborne bacteriophage represents a substantial reservoir of antibiotic resistance and that bacteriophage could play a significant role in the horizontal transfer of resistance genes in the context of an agricultural soil microbiome. Overall, our work reinforces the advisability of composting or digesting fecal material prior to field application and suggests that application of some antibiotics at subclinical concentrations can promote bacteriophage-mediated horizontal transfer of ARGs in agricultural soil microbiomes.
Autoinduction Specificities of the Lantibiotics Subtilin and Nisin
Authors: Spieß Tobias , Korn Sophie Marianne , Kötter Peter , Entian Karl-Dieter
Published: September 2015

The biosynthesis of the lantibiotics subtilin and nisin is regulated by autoinduction via two-component systems. Although subtilin is structurally closely related to nisin and contains the same lanthionine ring structure, both lantibiotics specifically autoinduce their biosynthesis. Subtilin and also the subtilin-like lantibiotics entianin and ericin autoinduce the two-component system SpaRK of
Bacillus subtilis
, whereas the biosynthesis of nisin is autoinduced via the two-component system NisRK of
Lactococcus lactis
. Autoinduction is highly specific for the respective lantibiotic and therefore of major importance for the functional expression of genetically engineered subtilin-like lantibiotics. To identify the structural features required for subtilin autoinduction, subtilin-nisin hybrids and specific point mutations of amino acid position 1 were generated. For subtilin autoinduction, the N-terminal tryptophan is the most important for full SpaK activation. The failure of subtilin to autoinduce the histidine kinase NisK mainly depends on the N-terminal tryptophan, as its single exchange to the aliphatic amino acid residues isoleucine, leucine, and valine provided NisK autoinduction. In addition, the production of subtilin variants which did not autoinduce their own biosynthesis could be rescued upon heterologous coexpression in
B. subtilis
DSM15029 by the autoinducing subtilin-like lantibiotic entianin.
pH Regulates White-Opaque Switching and Sexual Mating in Candida albicans
Authors: Sun Yuan , Cao Chengjun , Jia Wei , Tao Li , Guan Guobo , Huang Guanghua
Published: September 2015

As a successful commensal and pathogen of humans,
Candida albicans
encounters a wide range of environmental conditions. Among them, ambient pH, which changes frequently and affects many biological processes in this species, is an important factor, and the ability to adapt to pH changes is tightly linked with pathogenesis and morphogenesis. In this study, we report that pH has a profound effect on white-opaque switching and sexual mating in
C. albicans
. Acidic pH promotes white-to-opaque switching under certain culture conditions but represses sexual mating. The Rim101-mediated pH-sensing pathway is involved in the control of pH-regulated white-opaque switching and the mating response. Phr2 and Rim101 could play a major role in acidic pH-induced opaque cell formation. Despite the fact that the cyclic AMP (cAMP) signaling pathway does not play a major role in pH-regulated white-opaque switching and mating, white and opaque cells of the
cyr1/cyr1
mutant, which is defective in the production of cAMP, showed distinct growth defects under acidic and alkaline conditions. We further discovered that acidic pH conditions repressed sexual mating due to the failure of activation of the Ste2-mediated α-pheromone response pathway in opaque
a
cells. The effects of pH changes on phenotypic switching and sexual mating could involve a balance of host adaptation and sexual reproduction in
C. albicans
.
Associations between time in bed and suicidal thoughts, plans and attempts in Korean adolescents
Authors: Kim Jae-Hyun , Park Eun-Cheol , Lee Sang Gyu , Yoo Ki-Bong
Published: September 2015

Objectives

To examine the hypothesis that respondents with any of three specific sleep patterns would have a higher likelihood of suicidality than those without reports of these patterns in Korean adolescents.

Setting

Data from the 2011–2013 Korea Youth Risk Behavior Web-based Survey were used.

Participants

191 642 subjects were included. The survey's target population was students in grades 7 through 12 in South Korea.

Independent variable

Sleep time.

Primary and secondary outcome measures

Suicidal thoughts, plans and attempts.

Results

The odds of suicidal thoughts in subjects with very short or long time in bed were 1.487-fold higher (95% CI 1.219 to 1.815) or 0.611-fold lower (95% CI 0.460 to 0.811), respectively, than for subjects with 7 h/day in bed; the odds were similar for suicidal plans. The odds of suicidal thoughts in subjects with early or late awakening times were 1.231-fold higher (95% CI 1.050 to 1.442) or 1.528-fold lower (95% CI 1.000 to 2.334), respectively, than for subjects with 7 h/day in bed; these odds were lower for suicidal plans and attempts. The odds of suicidal thoughts in subjects with early bedtime were 1.748-fold higher (95% CI 1.302 to 2.346), the odds of suicidal plans in people with an early bedtime were 2.494-fold higher (95% CI 1.671 to 3.722) and the odds of suicide attempts in subjects with late bedtime were 1.313-fold higher (95% CI 1.005 to 1.716) than for subjects with a bedtime of 23:00.

Conclusions

The sleep-related time is associated with suicide-related behaviours in Korean adolescents. Multilateral approaches are needed to identify the greatest risk factors for suicidal behaviours.
Sustained reductions in time to antibiotic delivery in febrile immunocompromised children: results of a quality improvement collaborative
Authors: Dandoy Christopher E , Hariharan Selena , Weiss Brian , Demmel Kathy , Timm Nathan , Chiarenzelli Janis , Dewald Mary Katherine , Kennebeck Stephanie , Langworthy Shawna , Pomales Jennifer , Rineair Sylvia , Sandfoss Erin , Volz-Noe Pamela , Nagarajan Rajaram , Alessandrini Evaline
Published: September 2015

Background

Timely delivery of antibiotics to febrile immunocompromised (F&I) paediatric patients in the emergency department (ED) and outpatient clinic reduces morbidity and mortality.

Objective

The aim of this quality improvement initiative was to increase the percentage of F&I patients who received antibiotics within goal in the clinic and ED from 25% to 90%.

Methods

Using the Model of Improvement, we performed Plan-Do-Study-Act cycles to design, test and implement high-reliability interventions to decrease time to antibiotics. Pre-arrival interventions were tested and implemented, followed by post-arrival interventions in the ED. Many processes were spread successfully to the outpatient clinic. The Chronic Care Model was used, in addition to active family engagement, to inform and improve processes.

Results

The study period was from January 2010 to January 2015. Pre-arrival planning improved our F&I time to antibiotics in the ED from 137 to 88 min. This was sustained until October 2012, when further interventions including a pre-arrival huddle decreased the median time to <50 min. Implementation of the various processes to the clinic delivery system increased the mean percentage of patients receiving antibiotics within 60 min to >90%. In September 2014, we implemented a rapid response team to improve reliable venous access in the ED, which increased our mean percentage of patients receiving timely antibiotics to its highest rate (95%).

Conclusions

This stepwise approach with pre-arrival planning using the Chronic Care Model, followed by standardisation of processes, created a sustainable improvement of timely antibiotic delivery in F&I patients.
Next day discharge after elective intracranial aneurysm coiling: is it safe?
Authors: Zakhari Nader , Lum Cheemun , Quateen Aiman , Iancu Daniela , Lesiuk Howard
Published: September 2015

Background

There is a paucity of literature on early discharge after elective aneurysm treatment. We hypothesize that patient discharge on the next day is not associated with an increase in post-discharge adverse events.

Methods

We retrospectively reviewed elective coiling procedures between 2009 and 2013. The primary outcome measure was 30-day adverse events (emergency department visits, readmission or prolonged admission >30 days, and death). We evaluated the association between early and standard discharge for the primary outcome using the Fisher exact test. We also assessed the association of the primary outcome with other patient and technical variables as well as findings on pre-discharge diffusion weighted imaging.

Results

We included 97 patients. Median length of hospital stay (LOS) was 2.52 days, and in 26 patients (26.8%) LOS was <2 days. There was no significant difference in post-discharge adverse outcome rates between early and standard discharge groups (19.2% vs 18.3%; p=1.000). The primary outcome was significantly associated with the use of flow diverters (p=0.0287) and change in modified Rankin Scale category at discharge (p=0.0329). No significant association was noted between the outcome and the other variables including the presence of diffusion restriction pre-discharge (p>0.05).

Conclusions

Patient discharge the next day after elective intracranial aneurysm coiling is not associated with an increase in 30-day adverse outcomes. A prospective study investigating early discharge in elective treatment is warranted.

Trial number

OHSN-REB #20130786-01H.
Technology in postgraduate medical education: a dynamic influence on learning?
Authors: Bullock Alison , Webb Katie
Published: September 2015

The influence of technology in medical workplace learning is explored by focusing on three uses: m-learning (notably apps), simulation and social media. Smartphones with point-of-care tools (such as textbooks, drug guides and medical calculators) can support workplace learning and doctors’ decision-making. Simulations can help develop technical skills and team interactions, and ‘in situ’ simulations improve the match between the virtual and the real. Social media (wikis, blogs, networking, YouTube) heralds a more participatory and collaborative approach to knowledge development. These uses of technology are related to Kolb’s learning cycle and Eraut’s intentions of informal learning. Contentions and controversies with these technologies exist. There is a problem with the terminology commonly adopted to describe the use of technology to enhance learning. Using learning technology in the workplace changes the interaction with others and raises issues of professionalism and etiquette. Lack of regulation makes assessment of app quality a challenge. Distraction and dependency are charges levelled at smartphone use in the workplace and these need further research. Unless addressed, these and other challenges will impede the benefits that technology may bring to postgraduate medical education.
Aquaporin-1 shifts the critical transmural pressure to compress the aortic intima and change transmural flow: theory and implications
Authors: Joshi Shripad , Jan Kung-Ming , Rumschitzki David S.
Published: September 2015

Transmural-pressure (ΔP)-driven plasma advection carries macromolecules into the vessel wall, the earliest prelesion atherosclerotic event. The wall's hydraulic conductivity, LP, the water flux-to-ΔP ratio, is high at low pressures, rapidly decreases, and remains flat to high pressures (Baldwin AL, Wilson LM. Am J Physiol Heart Circ Physiol 264: H26–H32, 1993; Nguyen T, Toussaint, Xue JD, Raval Y, Cancel CB, Russell LM, Shou S, Sedes Y, Sun O, Yakobov Y, Tarbell JM, Jan KM, Rumschitzki DS. Am J Physiol Heart Circ Physiol 308: H1051–H1064, 2015; Tedgui A, Lever MJ. Am J Physiol Heart Circ Physiol. 247: H784–H791, 1984. Shou Y, Jan KM, Rumschitzki DS. Am J Physiol Heart Circ Physiol 291: H2758–H2771, 2006) due to pressure-induced subendothelial intima (SI) compression that causes endothelial cells to partially block internal elastic laminar fenestrae. Nguyen et al. showed that rat and bovine aortic endothelial cells express the membrane protein aquaporin-1 (AQP1) and transmural water transport is both transcellular and paracellular. They found that LPlowering by AQP1 blocking was perplexingly ΔP dependent. We hypothesize that AQP1 blocking lowers average SI pressure; therefore, a lower ΔP achieves the critical force/area on the endothelium to partially block fenestrae. To test this hypothesis, we improve the approximate model of Huang et al. (Huang Y, Rumschitzki D, Chien S, Weinbaum SS. Am J Physiol Heart Circ Physiol 272: H2023–H2039, 1997) and extend it by including transcellular AQP1 water flow. Results confirm the observation by Nguyen et al.: wall LPand water transport decrease with AQP1 disabling. The model predicts 1) low-pressure LPexperiments correctly; 2) AQP1s contribute 30–40% to both the phenomenological endothelial + SI and intrinsic endothelial LP; 3) the force on the endothelium for partial SI decompression with functioning AQP1s at 60 mmHg equals that on the endothelium at ∼43 mmHg with inactive AQP1s; and 4) increasing endothelial AQP1 expression increases wall LPand shifts the ΔP regime where LPdrops to significantly higher ΔP than in Huang et al. Thus AQP1 upregulation (elevated wall LP) might dilute and slow low-density lipoprotein binding to SI extracellular matrix, which may be beneficial for early atherogenesis.
Feeding the fibrillating heart: Dichloroacetate improves cardiac contractile dysfunction following VF
Authors: Azam Mohammed Ali , Wagg Cory S. , Massé Stéphane , Farid Talha , Lai Patrick F. H. , Kusha Marjan , Asta John , Jaimes Rafael , Kuzmiak-Glancy Sarah , Kay Matthew W. , Lopaschuk Gary D. , Nanthakumar Kumaraswamy
Published: September 2015

Ventricular fibrillation (VF) is an important cause of sudden cardiac arrest following myocardial infarction. Following resuscitation from VF, decreased cardiac contractile function is a common problem. During and following myocardial ischemia, decreased glucose oxidation, increased anaerobic glycolysis for cardiac energy production are harmful and energetically expensive. The objective of the present study is to determine the effects of dichloroacetate (DCA), a glucose oxidation stimulator, on cardiac contractile dysfunction following ischemia-induced VF. Male Sprague-Dawley rat hearts were Langendorff perfused in Tyrode's buffer. Once stabilized, hearts were subjected to 15 min of global ischemia and 5 min of aerobic reperfusion in the presence or absence of DCA. At the 6th min of reperfusion, VF was induced electrically, and terminated. Left ventricular (LV) pressure was measured using a balloon. Pretreatment with DCA significantly improved post-VF left ventricular developed pressure (LVDP) and dp/d tmax. In DCA-pretreated hearts, post-VF lactate production and pyruvate dehydrogenase (PDH) phosphorylation were significantly reduced, indicative of stimulated glucose oxidation, and inhibited anaerobic glycolysis by activation of PDH. Epicardial NADH fluorescence was increased during global ischemia above preischemic levels, but decreased below preischemia levels following VF, with no differences between nontreated controls and DCA-pretreated hearts, whereas DCA pretreatment increased NADH production in nonischemic hearts. With exogenous fatty acids (FA) added to the perfusion solution, DCA pretreatment also resulted in improvements in post-VF LVDP and dp/d tmax, indicating that the presence of exogenous FA did not affect the beneficial actions of DCA. In conclusion, enhancement of PDH activation by DCA mitigates cardiac contractile dysfunction following ischemia-induced VF.
Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations
Authors: Leone Marina , Magadum Ajit , Engel Felix B.
Published: September 2015

The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major goal in experimental medicine is to elucidate the molecular mechanisms underlying the regenerative capacity of these species. A wide variety of experiments have demonstrated that naturally occurring heart regeneration relies on cardiomyocyte proliferation. Thus, major efforts have been invested to induce proliferation of mammalian cardiomyocytes in order to improve cardiac function after injury or to protect the heart from further functional deterioration. In this review, we describe and analyze methods currently used to evaluate cardiomyocyte proliferation. In addition, we summarize the literature on naturally occurring heart regeneration. Our analysis highlights that newt and zebrafish heart regeneration relies on factors that are also utilized in cardiomyocyte proliferation during mammalian fetal development. Most of these factors have, however, failed to induce adult mammalian cardiomyocyte proliferation. Finally, our analysis of mammalian neonatal heart regeneration indicates experiments that could resolve conflicting results in the literature, such as binucleation assays and clonal analysis. Collectively, cardiac regeneration based on cardiomyocyte proliferation is a promising approach for improving adult human cardiac function after injury, but it is important to elucidate the mechanisms arresting mammalian cardiomyocyte proliferation after birth and to utilize better assays to determine formation of new muscle mass.
Sex differences in the expression of lung inflammatory mediators in response to ozone
Authors: Cabello Noe , Mishra Vikas , Sinha Utkarshna , DiAngelo Susan L. , Chroneos Zissis C. , Ekpa Ndifreke A. , Cooper Timothy K. , Caruso Carla R. , Silveyra Patricia
Published: September 2015

Sex differences in the incidence of respiratory diseases have been reported. Women are more susceptible to inflammatory lung disease induced by air pollution and show worse adverse pulmonary health outcomes than men. However, the mechanisms underlying these differences remain unknown. In the present study, we hypothesized that sex differences in the expression of lung inflammatory mediators affect sex-specific immune responses to environmental toxicants. We focused on the effects of ground-level ozone, a major air pollutant, in the expression and regulation of lung immunity genes. We exposed adult male and female mice to 2 ppm of ozone or filtered air (control) for 3 h. We compared mRNA levels of 84 inflammatory genes in lungs harvested 4 h postexposure using a PCR array. We also evaluated changes in lung histology and bronchoalveolar lavage fluid cell counts and protein content at 24 and 72 h postexposure. Our results revealed sex differences in lung inflammation triggered by ozone exposure and in the expression of genes involved in acute phase and inflammatory responses. Major sex differences were found in the expression of neutrophil-attracting chemokines ( Ccl20, Cxcl5, and Cxcl2), the proinflammatory cytokine interleukin-6, and oxidative stress-related enzymes ( Ptgs2, Nos2). In addition, the phosphorylation of STAT3, known to mediate IL-6-related immune responses, was significantly higher in ozone-exposed mice. Together, our observations suggest that a differential regulation of the lung immune response could be implicated in the observed increased susceptibility to adverse health effects from ozone observed in women vs. men.
Antenatal endotoxin disrupts lung vitamin D receptor and 25-hydroxyvitamin D 1α-hydroxylase expression in the developing rat
Authors: Mandell Erica , Seedorf Gregory J. , Ryan Sharon , Gien Jason , Cramer Scott D. , Abman Steven H.
Published: September 2015

Vitamin D [vit D; 1,25-(OH)2D] treatment improves survival and lung alveolar and vascular growth in an experimental model of bronchopulmonary dysplasia (BPD) after antenatal exposure to endotoxin (ETX). However, little is known about lung-specific 1,25-(OH)2D3regulation during development, especially regarding maturational changes in lung-specific expression of the vitamin D receptor (VDR), 1α-hydroxylase (1α-OHase), and CYP24A1 during late gestation and the effects of antenatal ETX exposure on 1,25-(OH)2D3metabolism in the lung. We hypothesized that vit D regulatory proteins undergo maturation regulation in the late fetal and early neonatal lung and that prenatal exposure to ETX impairs lung growth partly through abnormal endogenous vit D metabolism. Normal fetal rat lungs were harvested between embryonic day 15 and postnatal day 14. Lung homogenates were assayed for VDR, 1α-OHase, and CYP24A1 protein contents by Western blot analysis. Fetal rats were injected on embryonic day 20 with intra-amniotic ETX, ETX + 1,25-(OH)2D3, or saline and delivered 2 days later. Pulmonary artery endothelial cells (PAECs) from fetal sheep were assessed for VDR, 1α-OHase, and CYP24A1 expression after treatment with 25-(OH)D3, 1,25-(OH)2D3, ETX, ETX + 25-(OH)D3, or ETX + 1,25-(OH)2D3. We found that lung VDR, 1α-OHase, and CYP2741 protein expression dramatically increase immediately before birth ( P < 0.01 vs. early fetal values). Antenatal ETX increases CYP24A1 expression ( P < 0.05) and decreases VDR and 1α-OHase expression at birth ( P < 0.001), but these changes are prevented with concurrent vit D treatment ( P < 0.001). ETX-induced reduction of fetal PAEC growth and tube formation and lung 1α-OHase expression are prevented by vit D treatment ( P < 0.001). We conclude that lung VDR, 1α-OHase, and CYP24A1 protein content markedly increase before birth and that antenatal ETX disrupts lung vit D metabolism through downregulation of VDR and increased vit D catabolic enzyme expression, including changes in developing endothelium. We speculate that endogenous vitamin D metabolism modulates normal fetal lung development and that prenatal disruption of vit D signaling may contribute to impaired postnatal lung growth at least partly through altered angiogenic signaling.
Breast Cancer Cells Respond Differentially to Modulation of TGFβ2 Signaling after Exposure to Chemotherapy or Hypoxia
Authors: O'Brien Siobhan K. , Chen Liang , Zhong Wenyan , Armellino Douglas , Yu Jiyang , Loreth Christine , Follettie Maximillian , Damelin Marc
Published: September 2015

Intratumoral heterogeneity helps drive the selection for diverse therapy-resistant cell populations. In this study, we demonstrate the coexistence of two therapy-resistant populations with distinct properties that are reproducibly enriched under conditions that characterize tumor pathophysiology. Breast cancer cells that survived chemotherapy or hypoxia were enriched for cells expressing the major hyaluronic acid receptor CD44. However, only CD44hi cells that survived chemotherapy exhibited cancer stem cell (CSC) phenotypes based on growth potential and gene expression signatures that represent oncogenic signaling and metastatic prowess. Strikingly, we identified TGFβ2 as a key growth promoter of CD44hi cells that survived chemotherapy but also as a growth inhibitor of cells that survived hypoxia. Expression of the TGFβ receptor TGFβR1 and its effector molecule SMAD4 was required for enrichment of CD44hi cells exposed to the chemotherapeutic drug epirubicin, which suggests a feed-forward loop to enrich for and enhance the function of surviving CSCs. Our results reveal context-dependent effects of TGFβ2 signaling in the same tumor at the same time. The emergence of distinct resistant tumor cell populations as a consequence of prior therapeutic intervention or microenvironmental cues has significant implications for the responsiveness of recurring tumors to therapy. Cancer Res; 75(21); 4605–16. ©2015 AACR.
Post-transcriptional Modifications Contribute to the Upregulation of Cyclin D2 in Multiple Myeloma
Authors: Misiewicz-Krzeminska Irena , Sarasquete María E. , Vicente-Dueñas Carolina , Krzeminski Patryk , Wiktorska Katarzyna , Corchete Luis Antonio , Quwaider Dalia , Rojas Elizabeta A. , Corral Rocío , Martín Ana A. , Escalante Fernando , Bárez Abelardo , García Juan Luis , Sánchez-García Isidro , García-Sanz Ramón , San Miguel Jesús F. , Gutiérrez Norma C.
Published: September 2015

Purpose: Dysregulation of one of the three D-cyclin genes has been observed in virtually all multiple myeloma tumors. The mechanisms by which CCND2 is upregulated in a set of multiple myeloma are not completely deciphered. We investigated the role of post-transcriptional regulation through the interaction between miRNAs and their binding sites at 3′UTR in CCND2 overexpression in multiple myeloma.

Experimental Design: Eleven myeloma cell lines and 45 primary myeloma samples were included in the study. Interactions between miRNAs deregulated in multiple myeloma and mRNA targets were analyzed by 3′UTR-luciferase plasmid assay. The presence of CCND2 mRNA isoforms different in length was explored using qRT-PCR, Northern blot, mRNA FISH, and 3′ rapid amplification of cDNA ends (RACE)-PCR.

Results: We detected the presence of short CCND2 mRNA, both in the multiple myeloma cell lines and primary cells. The results obtained by 3′RACE experiments revealed that changes in CCND2 3′UTR length are explained by alternative polyadenylation. The luciferase assays using plasmids harboring the truncated CCND2 mRNA strongly confirmed the loss of miRNA sites in the shorter CCND2 mRNA isoform. Those multiple myelomas with greater abundance of the shorter 3′UTR isoform were associated with significant higher level of total CCND2 mRNA expression. Furthermore, functional analysis showed significant CCND2 mRNA shortening after CCND1 silencing and an increased relative expression of longer isoform after CCND1 and CCND3 overexpression, suggesting that cyclin D1 and D3 could regulate CCND2 levels through modifications in polyadenylation-cleavage reaction.

Conclusions: Overall, these results highlight the impact of CCND2 3′UTR shortening on miRNA-dependent regulation of CCND2 in multiple myeloma. Clin Cancer Res; 22(1); 207–17. ©2015 AACR.
New DNA Methylation Markers and Global DNA Hypomethylation Are Associated with Oral Cancer Development
Authors: Foy Jean-Philippe , Pickering Curtis R. , Papadimitrakopoulou Vassiliki A. , Jelinek Jaroslav , Lin Steven H. , William William N. , Frederick Mitchell J. , Wang Jing , Lang Wenhua , Feng Lei , Zhang Li , Kim Edward S. , Fan You H. , Hong Waun K. , El-Naggar Adel K. , Lee J. Jack , Myers Jeffrey N. , Issa Jean-Pierre , Lippman Scott M. , Mao Li , Saintigny Pierre
Published: September 2015

DNA promoter methylation of tumor suppressor genes and global DNA hypomethylation are common features of head and neck cancers. Our goal was to identify early DNA methylation changes in oral premalignant lesions (OPL) that may serve as predictive markers of developing oral squamous cell carcinoma (OSCC). Using high-throughput DNA methylation profiles of 24 OPLs, we found that the top 86 genes differentially methylated between patients who did or did not develop OSCC were simultaneously hypermethylated, suggesting that a CpG island methylation phenotype may occur early during OSCC development. The vast majority of the 86 genes were nonmethylated in normal tissues and hypermethylated in OSCC versus normal mucosa. We used pyrosequencing in a validation cohort of 44 patients to evaluate the degree of methylation of AGTR1, FOXI2, and PENK promoters CpG sites that were included in the top 86 genes and of LINE1 repetitive element methylation, a surrogate of global DNA methylation. A methylation index was developed by averaging the percent methylation of AGTR1, FOXI2, and PENK promoters; patients with a high methylation index had a worse oral cancer–free survival (P = 0.0030). On the other hand, patients with low levels of LINE1 methylation had a significantly worse oral cancer–free survival (P = 0.0153). In conclusion, AGTR1, FOXI2, and PENK promoter methylation and LINE1 hypomethylation may be associated with an increased risk of OSCC development in patients with OPLs. Cancer Prev Res; 8(11); 1027–35. ©2015 AACR.
Statin Therapy May not Effect NLR and MPV Levels in Patients With Hypercholesterolemia
Authors: Gungoren Fatih , Besli Feyzullah , Caliskan Serhat , Polat Ufuk , Basar Cengiz , Serdar Osman Akin
Published: September 2015

Statins may exert pleiotropic effects in coronary artery disease (CAD), diabetes mellitus, and familial hypercholesterolemia. We evaluated the effects of statins on the neutrophil–lymphocyte ratio (NLR) and mean platelet volume (MPV) in 261 consecutive patients with hypercholesterolemia having CAD or at high cardiovascular (CV) risk and 50 healthy participants who were retrospectively included in this study. Patients were treated with 10 to 80 mg atorvastatin or 10 to 40 mg rosuvastatin for 24 weeks according to baseline levels of cholesterol, triglycerides, and CV risk. Baseline NLR and MPV were significantly higher in patients with CAD or at high risk compared to the control group (1.89 [0.37-6.78]) vs 1.44 [0.75-2.41], P < .001 and 8.8 [6.27-18.6] vs 8.45 [6-11] fL, P = .038, respectively). The NLR, MPV, and lipid parameters were also compared in the patient group after statin treatment for 24 weeks. Lipid levels decreased but the NLR and MPV did not change significantly after the statin therapy. Further studies are needed to clarify the effect of statin therapy on NLR and MPV in patients with CAD or at high CV risk.
Five-year review of a UK 24 hour testing service for plasma ethylene glycol and diethylene glycol
Authors: Ford Loretta T , Berg Jonathan D
Published: September 2015

Background

We present a 5-year review of our UK service for plasma ethylene glycol and diethylene glycol determination in cases of acute poisoning.

Methods

Ethylene glycol and diethylene glycol have been measured on all samples received for screening for toxicity by gas chromatography-flame ionization detection over a five-year period. A detailed audit of the results has been undertaken.

Results

In this period, we received 811 requests, 56% were for first-time screening and 44% repeat analysis where a positive sample has already been received. Of the first-time screen samples, 33.5% screened positive for glycol poisoning. The mean positive ethylene glycol concentration was 1204 mg/L (range 31 to 8666 mg/L). Diethylene glycol was present in 14% of ethylene glycol positive samples but never found alone.

Conclusions

The data presented here suggest it is not essential to measure diethylene glycol since its inclusion is rarely likely to change patient management.
Simultaneous analysis of urinary metabolites for preliminary identification of primary hyperoxaluria
Authors: Clifford-Mobley Oliver , Hewitt Laura , Rumsby Gill
Published: September 2015

Background

The primary hyperoxalurias are inherited disorders of glyoxylate metabolism, which cause over-production of oxalate leading to urolithiasis and subsequent renal failure. Other metabolites may be produced in excess in the different forms of PH: glycolate in PH1, glycerate in PH2 and 4-hydroxy-2-oxoglutarate and 2,4-dihydroxyglutarate in PH3. The aim of this study was to set up and validate a method for the simultaneous analysis of these metabolites in urine and to evaluate its use for preliminary identification of primary hyperoxaluria prior to definitive diagnosis by genetic testing.

Methods

Urine samples were derivitized by methoximation and silylation and extracted into organic solvent prior to analysis by gas chromatography mass spectrometry.

Results

Recovery of the analytes spiked into urine ranged from 91 to 103% and total analytical imprecision ranged from 3.0 to 13.6%. 4-Hydroxy-2-oxoglutarate was unstable in urine at room temperature, and preservation by acidification was required. Mean urinary glycolate, glycerate and 4-hydroxy-2-oxoglutarate or 2,4-dihydroxyglutarate (expressed as a ratio to creatinine) were significantly higher in patients with PH1, PH2 and PH3, respectively. Low 4-hydroxy-2-oxoglutarate was observed in some patients with PH3, probably due to the instability of this analyte, but all PH3 patients had elevated 2,4-dihydroxyglutarate. During five months of routine service, seven cases of PH were identified by this method and subsequently confirmed by gene sequencing including two with novel mutations in HOGA1.

Conclusions

This study confirms that the method is useful in aiding the diagnosis of primary hyperoxaluria and can direct genetic testing.
Visual Inspection Reliability for Precision Manufactured Parts
Authors: See Judi E.
Published: September 2015

Objective:

Sandia National Laboratories conducted an experiment for the National Nuclear Security Administration to determine the reliability of visual inspection of precision manufactured parts used in nuclear weapons.

Background:

Visual inspection has been extensively researched since the early 20th century; however, the reliability of visual inspection for nuclear weapons parts has not been addressed. In addition, the efficacy of using inspector confidence ratings to guide multiple inspections in an effort to improve overall performance accuracy is unknown. Further, the workload associated with inspection has not been documented, and newer measures of stress have not been applied.

Method:

Eighty-two inspectors in the U.S. Nuclear Security Enterprise inspected 140 parts for eight different defects.

Results:

Inspectors correctly rejected 85% of defective items and incorrectly rejected 35% of acceptable parts. Use of a phased inspection approach based on inspector confidence ratings was not an effective or efficient technique to improve the overall accuracy of the process. Results did verify that inspection is a workload-intensive task, dominated by mental demand and effort.

Conclusion:

Hits for Nuclear Security Enterprise inspection were not vastly superior to the industry average of 80%, and they were achieved at the expense of a high scrap rate not typically observed during visual inspection tasks.

Application:

This study provides the first empirical data to address the reliability of visual inspection for precision manufactured parts used in nuclear weapons. Results enhance current understanding of the process of visual inspection and can be applied to improve reliability for precision manufactured parts.
Finite element analysis of hygrothermal effects on angle-ply composite plates
Authors: Zhen Wu , Xiaohui Ren
Published: September 2015

Analytical and numerical results on transverse shear stresses of angle-ply composite plates subjected to hygrothermal loadings are scarce in literature. Thus, a higher order global-local model a priori satisfying the continuity condition of transverse shear stresses is proposed for hygrothermal analysis of angel-ply composite plates. Based on the higher order global-local model, a triangular element is developed by using the refined element approach. Comparing the results from available three-dimensional elasticity solution, the proposed model can produce promising transverse shear stresses directly from constitutive equations without any smoothing technique. By analyzing hygrothermal response of composite plates with general configurations, the effects of material properties, lamination angles, boundary conditions, transverse normal strain, and hygrothermal expansion coefficients on the hygrothermal response have also been studied. Differing from previous work, the corrected hygrothermal expansion coefficients are used for hygrothermal analysis of composite plates.
Determination of the mode I, mode II, and mixed-mode I–II delamination toughness of a graphite/polyimide composite at room and elevated temperatures
Authors: Czabaj Michael W , Davidson Barry D
Published: September 2015

A study is described in which the mode I, mode II, and mixed-mode delamination toughnesses of a woven fabric graphite/polyimide composite are determined at room temperature and at 300℃. It is shown that, with some modifications, commonly used delamination toughness test methods can be extended for use into this relatively high-temperature regime. At room temperature, the mode II toughness was found to be significantly higher than that obtained in mode I. Relative to their fracture toughnesses at room temperature, the mode I and mixed-mode toughnesses increased at elevated temperature, while the mode II toughness decreased. Thus, at 300℃, the mode I toughness was larger than that obtained for mode II. The temperature dependence in all three modes was found to be consistent with what is predicted based on micromechanical considerations for the effects of temperature on the resin. In addition, the local tow orientations influenced the fracture path and produced toughening mechanisms that were both temperature and mode mix dependent.
Enhancement in tribological behaviour of functionally graded SiC reinforced aluminium composites by centrifugal casting
Authors: Karun Akhil S , Rajan TPD , Pillai UTS , Pai BC , Rajeev VR , Farook A
Published: September 2015

Enhanced tribological and location-specific properties achieved in functionally graded metallic composites make them potential materials for futuristic engineering components. The present investigation aims on the processing of homogenous and functionally graded Al matrix composites reinforced with SiC particles of 23 µm average particle size by gravity and centrifugal casting techniques. The sizes of the primary aluminium and eutectic silicon phases are finer towards the outer periphery due to the higher solidification rate. Functionally graded Al–SiCp composite rings produced by centrifugal casting show higher concentration of SiCp towards outer periphery, followed by a gradient transition region and the particle depleted zone. Particle agglomerates formed due to partially wetted particles associated with voids and gas porosities segregate towards the inner periphery. The higher concentration of reinforcement particles near the outer periphery in FGM enhances the hardness and wear resistance in rotary and reciprocating wear studies. Centrifugal cast alloys show enhanced wear resistance than the gravity cast specimen due to fine grains of primary aluminium and eutectic silicon. The rotary and reciprocating wear test shows the adhesive and abrasive type wear mechanisms.
An investigation on the aging responses and corrosion behaviour of A356/SiC composites by neural network: The effect of cold working ratio
Authors: Tuntas Remzi , Dikici Burak
Published: September 2015

In the present study, an artificial neural network model has been used for predicting the corrosion behaviour, aging and hardness responses of aluminium-based metal matrix composites reinforced with silicon carbide particle. Hyperbolic tangent sigmoid and linear activation functions are employed as the most appropriate activation function for hidden and output layers, respectively. The developed artificial neural network model is used to predict the corrosion current density, peak aging time and peak hardness of the composites. Feed forward back propagation neural network has been trained by Levenberg Marquardt algorithm. The regression correlation coefficients ( R2) between the predicted and the experimental values of the corrosion current densities are found as 0.99986, 0.99629 and 0.99671 for the training, testing and validation datasets, respectively. Also, some case studies have been predicted by artificial neural network model. Test results indicate that the proposed network can be used efficiently for the prediction of the polarization response, peak aging time and peak hardness of the composites for different SiC volume fractions and deformation ratio without using any experimental data.