bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistance to cisplatin‐induced cell death conferred by the activity of organic anion transporting polypeptides (OATP) in human melanoma cells
Authors: Silvy Françoise , Lissitzky Jean‐Claude , Bruneau Nadine , Zucchini Nathalie , Landrier Jean‐François , Lombardo Dominique , Verrando Patrick
Published: April 2013

Expression of organic anion transporting polypeptides (OATP) transporters can be modified with potential incidence in cancers, yet they have not been considered in melanoma. Here, we demonstrate transcriptional and protein expression of OATP members in human melanoma cell lines with sodium‐independent organic anion uptake activity. Importantly, uptake of different organic anions over 24 h led to a common resistance signal to apoptotic cell death, induced further by cisplatin in 24 h. The mechanism is not dependent on the transport of cisplatin by the OATP, as it is not an OATP substrate. The resistance signal was modulated by PKC, disclosing it as signal mediator. This study suggests that OATP, which can be constantly activated by endobiotics, may contribute to melanoma chemotherapeutic resistance, thereby justifying the development of OATP targeting strategies.
Cognitive–behavioral therapy modifies the naturalistic course of social anxiety disorder: Findings from an ABA design study in routine clinical practices
Authors: Furukawa Toshi A. , Nakano Yumi , Funayama Tadashi , Ogawa Sei , Ietsugu Tetsuji , Noda Yumiko , Chen Junwen , Watanabe Norio , Akechi Tatsuo
Published: April 2013

Aims

While randomized evidence appears to have established efficacy of cognitive–behavioral therapy (CBT) and some pharmacotherapy for social anxiety disorder (SAD), their real‐world effectiveness has been called into question by long‐term naturalistic cohort studies of patients with SAD as they show very low probability of recovery and sustained social dysfunctions despite some drug and psychological therapies.

Method

The present study examines the effectiveness of group CBT for SAD in real‐world settings (n = 62) by examining the course of patients' symptomatology and social functions through approximately 6 months on the waiting list, through 6 months receiving the manualized group CBT intervention consisting of 16 2‐h sessions, and for 12 months after the treatment.

Results

We found: (i) that the patients with SAD changed little or possibly worsened through the 6 months on the waiting list, although two in three of them were on antidepressants, benzodiazepines or both; (ii) that both their symptomatology and social function improved significantly and substantively through the group CBT; and (iii) that this improvement was maintained through the 3‐ and 12‐month follow ups.

Conclusions

We can implement and must disseminate evidence‐based, effective CBT for more patients with SAD to lessen their suffering and stop the perpetuation of their symptoms.
Assessing The Positional Accuracy Of Airborne Laser Scanning in urban areas
Authors: Höhle Joachim
Published: April 2013

A new method for assessment of the absolute positional accuracy of lidar point clouds is described. It is based on the plane surfaces of building roofs which are derived from laser footprints. Three such planes intersect at a point and the coordinates of several of these well‐defined points are compared with points determined from aerial photography. From the differences obtained accuracy measures are derived. An analysis regarding the type of error distribution is carried out in order to determine whether to apply either standard or robust accuracy measures. Confidence intervals are derived for each accuracy measure by means of a unique computational method. A practical test with the proposed method revealed a high precision in the intersected points. The absolute positional accuracy of the lidar point cloud was determined with both standard and robust accuracy measures; the latter always produced smaller values. Suggestions for standards in the assessment of the positional accuracy of laser point clouds are made.
Automated Imaging and other developments in whole‐organism anthelmintic screening
Authors: Paveley R. A. , Bickle Q. D.
Published: April 2013

Helminth infections still represent a huge public health problem throughout the developing world and in the absence of vaccines control is based on periodic mass drug administration. Poor efficacy of some anthelmintics and concerns about emergence of drug resistance has highlighted the need for new drug discovery. Most current anthelmintics were discovered through in vivo screening of selected compounds in animal models but recent approaches have shifted towards screening for activity against adult or larval stages in vitro. Larvae are normally available in greater numbers than adults, can often be produced in vitro and are small enough for microplate assays. However, the manual visualization of drug effects in vitro is subjective, laborious and slow. This can be overcome by application of automated readouts including high‐content imaging. Incorporated into robotically controlled HTS platforms such methods allow the very large compound collections being made available by the pharmaceutical industry or academic organizations to be screened against helminths for the first time, invigorating the drug discovery pipeline. Here, we review the status of whole‐organism screens based on in vitro activity against living worms and highlight the recent progress towards automated image‐based readouts.
A lack of mitochondrial alternative oxidase compromises capacity to recover from severe drought stress
Authors: Wang Jia , Vanlerberghe Greg C.
Published: April 2013

Alternative oxidase (AOX) constitutes a nonenergy conserving branch of the mitochondrial electron transport chain. AOX activity may be important to avoid reactive oxygen species (ROS) generation by the chain, particularly during abiotic stress. We compared leaf AOX1a transcript and AOX protein amounts in wild‐type (WT) Nicotiana tabacum plants experiencing mild to severe drought. Mild to moderate drought resulted in a progressive and modest increase in AOX amount, accompanied by a progressive increased expression of different ROS‐scavenging components. Under these conditions, transgenic plants with suppressed AOX amount, due to an RNA interference construct, were not compromised in their ability to manage ROS load and prevent cellular damage. Severe drought stress, particularly when combined with increased irradiance, strongly increased AOX amount in WT tobacco and this coincided with an increase in total respiration and, despite further induction of ROS‐scavenging systems, some evidence of cellular damage. Under these severe conditions, plants lacking AOX suffered more cellular damage than WT and, at the most severe stage, were found to downregulate rather than upregulate the transcript level of several important ROS‐scavenging components. At this stage, WT plants could still recover rapidly after rewatering, but the recoverability of AOX knockdown plants was strongly compromised.
Influence of Seroreactivity to Leptospira and Reproductive Failures in Recipient Mares of Equine Embryo Transfer Programmes
Authors: Pinna A , Martins G , Souza G , Lilenbaum W
Published: April 2013

Contents

The aim of this study was to demonstrate that seroreactivity against Leptospira is significantly associated to the reproductive efficiency of recipient mares of an embryo transfer (ET) programme. A serosurvey was conducted from August 2007 to March 2009 in five herds from Rio de Janeiro, Brazil, with high rates of reproductive failure, as early embryonic death (>12%), abortion (>12%) and perinatal death. Detailed information about the losses was obtained from practitioner. A total of 338 recipient mares were tested by microscopic agglutination test, and 226 (66.9%) were seroreactive, mainly against serovars Bratislava and Copenhageni. Seroreactivity could be associated to reproductive failure (p < 0.001), and it was demonstrated that a seroreactive mare is 1.8 times more likely (relative risk – RR) to present reproductive failure than a seronegative one, particularly in relation to early embryonic death (p < 0.0001; RR 8.4) but also to abortions (p < 0.0001; RR 3.5), and to perinatal death (p < 0.05; RR 7.3). Therefore, seroreactivity to Leptospira is associated to reproductive failure in all phases of pregnancy in recipient mares, impairing equine ET programmes.
Immigrant Homeownership and Immigration Status: Evidence from Spain
Authors: Amuedo‐Dorantes Catalina , Mundra Kusum
Published: April 2013

Because of the many advantages of homeownership for immigrants and for the communities where immigrants reside, a variety of countries have implemented policies that facilitate immigrant homeownership. Although these policies hinge on immigration status, the link between immigration status and homeownership is yet to be carefully explored. Using a recent survey of immigrants in Spain, we find that permanent residents from the EU15 enjoy the highest homeownership rates, even after accounting for a wide range of individual and family characteristics known to impact housing ownership. Permanent residents from countries outside the EU15, temporary residents and undocumented immigrants are, respectively, 12, 29, and 33 percentage‐points less likely to own a home than permanent residents from the EU15. Overall, the findings highlight the differences in homeownership by immigrant status, possibly reflecting differences in cultural adaptation and integration across immigrants in the host country.
Earnings Gap, Cohort Effect and Economic Assimilation of Immigrants from Mainland China, Hong Kong, and Taiwan in the United States
Authors: Lin Carl
Published: April 2013

Using 1990, 2000 censuses and a 2010 survey, the economic performance of ethnically Chinese immigrants from mainland China, Hong Kong and Taiwan (CHT) in the US labor market is examined. Since 1990, relative wages of CHT migrants have been escalating in contrast to other immigrants. It is shown that these widening gaps are largely explained by individual's endowments, mostly education. Rising US‐earned degrees by CHT migrants can account for this relatively successful economic assimilation. Cohort analysis shows that the economic performance of CHT migrants admitted to the USA has been improving, even allowing for the effect of aging.
Migration and Diversity: Human versus Social Capital
Authors: Manole Vlad , Schiff Maurice
Published: April 2013

This paper examines the welfare implications associated with different degrees of diversity or similarity between migrants and natives under both migration and trade. We argue that the formation and use of social capital depend on culture. We use a general equilibrium model of migration, human capital, and social capital and find that there are three equilibrium solutions. Welfare under any of the equilibrium solutions rises with the diversity in human capital and decreases with the diversity in social capital between migrants and natives.
Invertible Coupled KdV and Coupled Harry Dym Hierarchies
Authors: Błaszak M. , Marciniak K.
Published: April 2013

In this paper, we discuss the conditions under which the coupled KdV and coupled Harry Dym hierarchies possess inverse (negative) parts. We further investigate the structure of nonlocal parts of tensor invariants of these hierarchies, in particular, the nonlocal terms of vector fields, conserved one‐forms, recursion operators, Poisson and symplectic operators. We show that the invertible coupled KdV hierarchies possess Poisson structures that are at most weakly nonlocal while coupled Harry Dym hierarchies have Poisson structures with nonlocalities of the third order.
Stratum corneum evaluation methods: overview
Authors: Myer Kaley , Maibach Howard
Published: April 2013

Background/purpose

The stratum corneum serves as a main barrier for the skin, minimizing water loss and regulating absorption of substances. Because of its surface location, it is readily available for analysis. Consequently, many techniques are amenable to investigating its content and function. Here, we review the methods employed to evaluate the stratum corneum and its function.

Methods

We reviewed Pubmed and Embase search results for ‘stratum corneum, ‘method,’ methods,’ ‘technique,’ and ‘evaluation’ and extracted pertinent articles that discussed ways to examine the stratum corneum and its constituents.

Results

Traditional and novel methods vary by accuracy, ease of use, time requirements, cost, invasiveness, and equipment requirements.

Conclusion

The methods reviewed all contribute to our current picture of the stratum corneum. Tape stripping continues to be the most widely used, but variations in the use of the corneocytes obtained further contribute to the diversity in evaluation methods.
Racial Neutrality by Any Other Name: An Examination of Collateral Consequence Policies in the United States
Authors: Christie Natasha V.
Published: April 2013

Objective

This study highlights the complex role that race plays in the restrictiveness of felon collateral consequence policies in the 50 states by introducing the combination of symbolic racism and racial threat as integral dimensions of the traditional race‐based arguments made in this policy area.

Methods

Using Alec Ewald's felon collateral consequence scores for the 50 states as the dependent variable and symbolic racism and racial threat variables as the major independent variables, an ordinary least squares (OLS) regression model estimated the effects of race‐based, ideological, political, and demographic independent variables on a state's felon collateral consequence score.

Results

The combination of symbolic racism and racial threat add an additional dimension to the traditional race‐policy connection within this policy area. Specifically, states with high levels of racial threat and symbolic racism were more likely to have higher felon collateral consequence scores. Yet, the presence of a state with a high level of black representatives in its state's legislature negated the effect of these variables.

Conclusions

Although similar studies have confirmed that racially neutral policies, such as felon collateral consequence policies, are affected by race, they have limited their discussion to one specific dimension—racial threat. The evidence presented in this study provided support for the inclusion of a multidimensional race‐based argument in this policy area.
Microbially mediated dolomite in Cambrian stromatolites from the Tarim Basin, north‐west China: implications for the role of organic substrate on dolomite precipitation
Authors: You Xuelian , Sun Shu , Zhu Jingquan , Li Qing , Hu Wenxuan , Dong Hailiang
Published: April 2013

Dolomite [CaMg(CO3)2] is abundant in sedimentary rocks throughout the geological record, but it is rarely found in modern sediments. Also, it cannot be precipitated under low‐temperature conditions in the laboratory without microbial mediation and, as a result, its origin remains a long‐standing enigma. This study reports biologically mediated dolomite precipitation in ancient microbial mats and biofilms from the Cambrian Tarim Basin. The ambient temperature at the time of dolomite precipitation was estimated from δ18O values from early diagenetic dolomite, and the presence of structures associated with extracellular polymeric substances (EPS), is composed of fibres arranged in a reticular pattern, would favour epitaxial crystallization of dolomite on an organic substrate. In addition, poorly crystallized dolomite formed nanocrystal aggregates that strongly resemble the morphology and size distribution observed in microbial culture experiments. These lines of evidence confirm that microbial structures can be preserved in ancient dolomite and validate their use as biosignatures.
Recurrence of preterm birth and perinatal mortality in northern Tanzania: registry‐based cohort study
Authors: Mahande Michael J. , Daltveit Anne K. , Obure Joseph , Mmbaga Blandina T. , Masenga Gileard , Manongi Rachel , Lie Rolv T.
Published: April 2013

Objectives

To estimate the recurrence risk of preterm delivery and estimate the perinatal mortality in repeated preterm deliveries.

Methods

Prospective study in Tanzania of 18 176 women who delivered a singleton between 2000 and 2008 at KCMC hospital. The women were followed up to 2010 for consecutive births. A total of 3359 women were identified with a total of 3867 subsequent deliveries in the follow‐up period. Recurrence risk of preterm birth and perinatal mortality was estimated using log‐binomial regression and adjusted for potential confounders.

Results

For women with a previous preterm birth, the risk of preterm birth in a subsequent pregnancy was 17%. This recurrence risk was estimated to be 2.7‐fold (95% CI: 2.1–3.4) of the risk of women with a previous term birth. The perinatal mortality of babies in a second preterm birth of the same woman was 15%. Babies born at term who had an older sibling that was born preterm had a perinatal mortality of 10%. Babies born at term who had an older sibling who was also born at term had a perinatal mortality of 1.7%.

Conclusion

Previous delivery of a preterm infant is a strong predictor of future preterm births in Tanzania. Previous or repeated preterm births increase the risk of perinatal death substantially in the subsequent pregnancy.
Granulocyte collections: comparison of two apheresis systems
Authors: Thorausch Kristin , Schulz Miriam , Bialleck Heike , Luxembourg Beate , Seifried Erhard , Bonig Halvard
Published: April 2013

Background

Donor granulocyte concentrates are routinely administered to patients with granulocyte function defects or transient neutropenia and (risk of) bacterial or fungal exacerbations, despite lack of definitive clinical proof for patient‐relevant outcome improvement. Granulocytes are collected by apheresis from healthy donors treated with granulocyte–colony‐stimulating factor and/or steroids for neutrophil mobilization the evening before apheresis, as well as with hydroxyethyl starch during apheresis, to enhance sedimentation of red blood cells (RBCs) and thus to facilitate accessibility of neutrophils for collection.

Study Design and Methods

Granulocyte apheresis procedures are performed with standard apheresis equipment, including with the frequently used apheresis system for peripheral blood “stem cell” collection, COBE Spectra MNC (Terumo BCT), using the same tubing set as for MNC collection, but a different software protocol, PMN. An automated apheresis system for granulocyte collection, Spectra Optia IDL (Terumo BCT), became available in October 2011. Since then, 70 granulocyte apheresis procedures have been performed at our site, 35 each with the new and old systems.

Results

Apheresis procedures were well tolerated throughout. The target dose of 1 × 1010 neutrophils was achieved in all but one collection with Spectra Optia IDL. Spectra Optia IDL collections were approximately 20% more efficient. Products contained more nontarget white blood cells (mononuclear cells), but fewer RBCs and platelets. Although less blood had to be processed with Spectra Optia IDL to achieve the same granulocyte dose, clinically relevant differences between the two apheresis devices were not apparent.

Conclusion

Both apheresis systems are similarly capable of generating granulocyte concentrates.
Physiology is rocking the foundations of evolutionary biology
Authors: Noble Denis
Published: April 2013

New Findings

What is the topic of this review?

Have recent experimental findings in evolutionary biology concerning the transmission of inheritance opened the way to a reintegration of physiology with evolutionary biology?

What advances does it highlight?

The answer is yes, and that this requires a new synthesis between evolutionary theory and experimental physiology.

The ‘Modern Synthesis’ (Neo‐Darwinism) is a mid‐20th century gene‐centric view of evolution, based on random mutations accumulating to produce gradual change through natural selection. Any role of physiological function in influencing genetic inheritance was excluded. The organism became a mere carrier of the real objects of selection, its genes. We now know that genetic change is far from random and often not gradual. Molecular genetics and genome sequencing have deconstructed this unnecessarily restrictive view of evolution in a way that reintroduces physiological function and interactions with the environment as factors influencing the speed and nature of inherited change. Acquired characteristics can be inherited, and in a few but growing number of cases that inheritance has now been shown to be robust for many generations. The 21st century can look forward to a new synthesis that will reintegrate physiology with evolutionary biology.
Heat stress does not augment ventilatory responses to presyncopal limited lower body negative pressure
Authors: Pearson J. , Ganio M. S. , Lucas R. A. I. , Babb T. G. , Crandall C. G.
Published: April 2013

New Findings

What is the central question of this study?

Simulated haemorrhage increases ventilation prior to presyncope, possibly increasing venous return through the respiratory pump. Heat stress alone also increases ventilation. It is unknown whether this increased ventilation would be greater with combined heat stress and simulated haemorrhage.

What is the main finding and its importance?

Our data suggest that the increased ventilation during simulated haemorrhage induced via lower body negative pressure is not altered in heat‐stressed humans. These findings have implications for individuals who are often heat stressed and at a higher risk of haemorrhagic injury. During a hypotensive challenge whilst heat stressed, these individuals are unlikely to realize benefits of a heightened respiratory pump relative to when they are normothermic.

Simulated haemorrhage, e.g. lower body negative pressure (LBNP), reduces central blood volume and mean arterial pressure, while ventilation increases. Passive whole‐body heat stress likewise increases ventilation. The objective of this project was to test the hypothesis that ventilatory responses to reductions in central blood volume and arterial pressure during simulated haemorrhage are enhanced when individuals are heat stressed rather than normothermic. Eight healthy men (34 ± 9 years old, 176 ± 6 cm tall and 80.2 ± 4.2 kg body weight) underwent a simulated haemorrhagic challenge via LBNP until presyncope on two separate occasions, namely normothermic control and whole‐body heat‐stress trials. Baseline ventilation and core and mean skin temperatures were not different between trials (all P > 0.05). Prior to LBNP, heat stress increased core (from 36.8 ± 0.2 to 38.2 ± 0.2°C, P < 0.05) and mean skin temperatures (from 33.9 ± 0.5 to 38.1 ± 0.6°C, P < 0.05), as well as minute ventilation (from 8.01 ± 2.63 to 13.68 ± 6.68 l min‐1, P < 0.01). At presyncope, mean arterial pressure and middle cerebral artery blood velocity decreased in both trials (P < 0.05). At presyncope, ventilation increased to 23.22 ± 6.78 (P < 0.01) and 25.88 ± 10.16 l min‐1 (P < 0.01) in the normothermic and hyperthermic trials, respectively; however, neither the increase in ventilation from the pre‐LBNP period nor the absolute ventilation was different between normothermic and hyperthermic trials (P > 0.05). These data suggest that the increase in ventilation during simulated haemorrhage induced via LBNP is not altered in heat‐stressed humans.
Resolution of hyposmotic stress in isolated mouse ventricular myocytes causes sealing of t‐tubules
Authors: Moench I. , Meekhof K. E. , Cheng L. F. , Lopatin A. N.
Published: April 2013

New Findings

What is the central question of this study?

The t‐tubules of ventricular myocytes are critical elements in excitation–contraction coupling. They become disorganized or even lost in various cardiac pathologies. However, the mechanisms leading to disruption of t‐tubules are essentially unknown. This study was designed to identify physiologically relevant processes that underlie remodelling of t‐tubules.

What is the main finding and its importance?

We show that the resolution of physiologically relevant hyposmotic swelling, not the application of osmotic shock itself, leads to dramatic t‐tubular remodelling, including the sealing of individual t‐tubules. The results point to an important and probably general mechanism of acute and fast stress‐induced t‐tubular remodelling that may underlie various relevant pathologies of the heart.

It has recently been shown that various stress‐inducing manipulations in isolated ventricular myocytes may lead to significant remodelling of t‐tubules. Osmotic stress is one of the most common complications in various experimental and clinical settings. This study was therefore designed to determine the effects of a physiologically relevant type of osmotic stress, hyposmotic challenge, to the integrity of the t‐tubular system in mouse ventricular myocytes using the following two approaches: (1) electrophysiological measurements of membrane capacitance and inward rectifier (IK1) tail currents originating from K+ accumulation in t‐tubules; and (2) confocal microscopy of fluorescent dextrans trapped in sealed t‐tubules. Importantly, we found that removal of ‘0.6 Na’ (60% NaCl) hyposmotic solution, but not its application to myocytes, led to a ∼27% reduction in membrane capacitance, a ∼2.5‐fold reduction in the amplitude of the IK1 tail current and a ∼2‐fold reduction in the so‐called IK1‘inactivation’ (due to depletion of t‐tubular K+) at negative membrane potentials; all these data were consistent with significant detubulation. Confocal imaging experiments also demonstrated that extracellularly applied dextrans become trapped in sealed t‐tubules only upon removal of hyposmotic solutions, i.e. during the shrinking phase, but not during the initial swelling period. In light of these data, relevant previous studies, including those on excitation–contraction coupling phenomena during hyposmotic stress, may need to be reinterpreted, and the experimental design of future experiments should take into account the novel findings.
Wet chemical etching process for wafer scale isolation and interconnection of GaSb based device layers grown on GaAs substrates
Authors: Min Kim Jung , Dutta Partha S. , Brown Eric , Borrego Jose M. , Greiff Paul
Published: April 2013

An optimized selective wet chemical etching process using potassium sodium tartrate solutions and citric acid solutions has been reported for wafer scale isolation and interconnection of GaSb based device structures grown on GaAs substrates. Uniformly etched surfaces with vertical side walls with minimal under-cutting and edge rounding, and smooth surface morphology have been achieved over a 2 in. (50 mm) diameter wafer using an optimized etching conditions, etchant preparation process, and specific ratios of the etchant ingredients. Repeatable etch rates for GaSb of approximately 330 nm/min and 12 nm/s for GaAs have been obtained. Using the developed process, wafer scale monolithically interconnected GaSb devices as well as modules on semi-insulating GaAs substrates can be fabricated for a variety of optoelectronic applications.
Physiological Characterization of an Anaerobic Ammonium-Oxidizing Bacterium Belonging to the “Candidatus Scalindua” Group
Authors: Awata Takanori , Oshiki Mamoru , Kindaichi Tomonori , Ozaki Noriatsu , Ohashi Akiyoshi , Okabe Satoshi
Published: April 2013

The phylogenetic affiliation and physiological characteristics (e.g.,

K
s

and maximum specific growth rate [μ
max
]) of an anaerobic ammonium oxidation (anammox) bacterium, “
Candidatus
Scalindua sp.,” enriched from the marine sediment of Hiroshima Bay, Japan, were investigated. “
Candidatus
Scalindua sp.” exhibits higher affinity for nitrite and a lower growth rate and yield than the known anammox species.
Effects of Experimental Exclusion of Scavengers from Carcasses of Anthrax-Infected Herbivores on Bacillus anthracis Sporulation, Survival, and Distribution
Authors: Bellan Steve E. , Turnbull Peter C. B. , Beyer Wolfgang , Getz Wayne M.
Published: April 2013

Scavenging of anthrax carcasses has long been hypothesized to play a critical role in the production of the infectious spore stage ofBacillus anthracisafter host death, though empirical studies assessing this are lacking. We comparedB. anthracisspore production, distribution, and survival at naturally occurring anthrax herbivore carcasses that were either experimentally caged to exclude vertebrate scavengers or left unmanipulated. We found no significant effect of scavengers on soil spore density (P> 0.05). Soil stained with terminally hemorrhaged blood and with nonhemorrhagic fluids exhibited high levels ofB. anthracisspore contamination (ranging from 103to 108spores/g), even in the absence of vertebrate scavengers. At most of the carcass sites, we also found that spore density in samples taken from hemorrhagic-fluid-stained soil continued to increase for >4 days after host death. We conclude that scavenging by vertebrates is not a critical factor in the life cycle ofB. anthracisand that anthrax control measures relying on deterrence or exclusion of vertebrate scavengers to prevent sporulation are unlikely to be effective.
Identification of Potentially Diarrheagenic Atypical Enteropathogenic Escherichia coli Strains Present in Canadian Food Animals at Slaughter and in Retail Meats
Authors: Comery Raven , Thanabalasuriar Ajitha , Garneau Philippe , Portt Andrea , Boerlin Patrick , Reid-Smith Richard J. , Harel Josï¿½e , Manges Amee R. , Gruenheid Samantha
Published: April 2013

This study identified and characterized enteropathogenic
Escherichia coli
(EPEC) in the Canadian food supply. Eighteen of 450
E. coli
isolates from food animal sources were identified as atypical EPEC (aEPEC). Several of the aEPEC isolates identified in this study possessed multiple virulence genes, exhibited adherence and attaching and effacing (A/E) lesion formation, disrupted tight junctions, and were coclassified with the extraintestinal pathogenic
E. coli
(ExPEC) and enterotoxigenic
E. coli
(ETEC) pathotypes.
Bacterial Communities Associated with Subsurface Geochemical Processes in Continental Serpentinite Springs
Authors: Brazelton William J. , Morrill Penny L. , Szponar Natalie , Schrenk Matthew O.
Published: April 2013

Reactions associated with the geochemical process of serpentinization can generate copious quantities of hydrogen and low-molecular-weight organic carbon compounds, which may provide energy and nutrients to sustain subsurface microbial communities independently of the photosynthetically supported surface biosphere. Previous microbial ecology studies have tested this hypothesis in deep sea hydrothermal vents, such as the Lost City hydrothermal field. This study applied similar methods, including molecular fingerprinting and tag sequencing of the 16S rRNA gene, to ultrabasic continental springs emanating from serpentinizing ultramafic rocks. These molecular surveys were linked with geochemical measurements of the fluids in an interdisciplinary approach designed to distinguish potential subsurface organisms from those derived from surface habitats. The betaproteobacterial genus
Hydrogenophaga
was identified as a likely inhabitant of transition zones where hydrogen-enriched subsurface fluids mix with oxygenated surface water. The
Firmicutes
genus
Erysipelothrix
was most strongly correlated with geochemical factors indicative of subsurface fluids and was identified as the most likely inhabitant of a serpentinization-powered subsurface biosphere. Both of these taxa have been identified in multiple hydrogen-enriched subsurface habitats worldwide, and the results of this study contribute to an emerging biogeographic pattern in which
Betaproteobacteria
occur in near-surface mixing zones and
Firmicutes
are present in deeper, anoxic subsurface habitats.
Susceptibility of Murine Norovirus and Hepatitis A Virus to Electron Beam Irradiation in Oysters and Quantifying the Reduction in Potential Infection Risks
Authors: Praveen Chandni , Dancho Brooke A. , Kingsley David H. , Calci Kevin R. , Meade Gloria K. , Mena Kristina D. , Pillai Suresh D.
Published: April 2013

Consumption of raw oysters is an exposure route for human norovirus (NoV) and hepatitis A virus (HAV). Therefore, efficient postharvest oyster treatment technology is needed to reduce public health risks. This study evaluated the inactivation of HAV and the NoV research surrogate, murine norovirus-1 (MNV-1), in oysters (
Crassostrea virginica
) by electron beam (E-beam) irradiation. The reduction of potential infection risks was quantified for E-beam irradiation technology employed on raw oysters at various virus contamination levels. The E-beam dose required to reduce the MNV and HAV titer by 90% (D
10
value) in whole oysters was 4.05 (standard deviations [SD], ï¿½0.63) and 4.83 (SD, ï¿½0.08) kGy, respectively. Microbial risk assessment suggests that if a typical serving of 12 raw oysters was contaminated with 10
5
PFU, a 5-kGy treatment would achieve a 12% reduction (from 4.49 out of 10 persons to 3.95 out of 10 persons) in NoV infection and a 16% reduction (from 9.21 out of 10 persons to 7.76 out of 10 persons) in HAV infections. If the serving size contained only 10
2
PFU of viruses, a 5-kGy treatment would achieve a 26% reduction (2.74 out of 10 persons to 2.03 out of 10 persons) of NoV and 91% reduction (2.1 out of 10 persons to 1.93 out of 100 persons) of HAV infection risks. This study shows that although E-beam processing cannot completely eliminate the risk of viral illness, infection risks can be reduced.
Comparative Transcription Profiling and In-Depth Characterization of Plasmid-Based and Plasmid-Free Escherichia coli Expression Systems under Production Conditions
Authors: Mairhofer Juergen , Scharl Theresa , Marisch Karoline , Cserjan-Puschmann Monika , Striedner Gerald
Published: April 2013

Plasmid-basedEscherichia coliBL21(DE3) expression systems are extensively used for the production of recombinant proteins. However, the combination of a high gene dosage with strong promoters exerts extremely stressful conditions on producing cells, resulting in a multitude of protective reactions and malfunctions in the host cell with a strong impact on yield and quality of the product. Here, we provide in-depth characterization of plasmid-based perturbations in recombinant protein production. A plasmid-free T7 system with a single copy of the gene of interest (GOI) integrated into the genome was used as a reference. Transcriptomics in combination with a variety of process analytics were used to characterize and compare a plasmid-free T7-based expression system to a conventional pET-plasmid-based expression system, with both expressing human superoxide dismutase in fed-batch cultivations. The plasmid-free system showed a moderate stress response on the transcriptional level, with only minor effects on cell growth. In contrast to this finding, comprehensive changes on the transcriptome level were observed in the plasmid-based expression system and cell growth was heavily impaired by recombinant gene expression. Additionally, we found that the T7 terminator is not a sufficient termination signal. Overall, this work reveals that the major metabolic burden in plasmid-based systems is caused at the level of transcription as a result of overtranscription of the multicopy product gene and transcriptional read-through of T7 RNA polymerase. We therefore conclude that the presence of high levels of extrinsic mRNAs, competing for the limited number of ribosomes, leads to the significantly reduced translation of intrinsic mRNAs.
Quantifying the Responses of Mixed Rumen Microbes to Excess Carbohydrate
Authors: Hackmann Timothy J. , Diese Leanne E. , Firkins Jeffrey L.
Published: April 2013

The aim of this study was to determine if a mixed microbial community from the bovine rumen would respond to excess carbohydrate by accumulating reserve carbohydrate, energy spilling (dissipating excess ATP energy as heat), or both. Mixed microbes from the rumen were washed with N-free buffer and dosed with glucose. Total heat production was measured by calorimetry. Energy spilling was calculated as heat production not accounted by (i) endogenous metabolism (heat production before dosing glucose) and (ii) synthesis of reserve carbohydrate (heat from synthesis itself and reactions yielding ATP for it). For cells dosed with 5 mM glucose, synthesis of reserve carbohydrate and endogenous metabolism accounted for nearly all heat production (93.7%); no spilling was detected (
P
= 0.226). For cells dosed with 20 mM glucose, energy spilling was not detected immediately after dosing, but it became significant (
P
< 0.05) by approximately 30 min after dosing with glucose. Energy spilling accounted for as much as 38.7% of heat production in one incubation. Nearly all energy (97.9%) and carbon (99.9%) in glucose were recovered in reserve carbohydrate, fermentation acids, CO
2
, CH
4
, and heat. This full recovery indicates that products were measured completely and that spilling was not a methodological artifact. These results should aid future research aiming to mechanistically account for variation in energetic efficiency of mixed microbial communities.
Prebiotic Content of Bread Prepared with Flour from Immature Wheat Grain and Selected Dextran-Producing Lactic Acid Bacteria
Authors: Pepe Olimpia , Ventorino Valeria , Cavella Silvana , Fagnano Massimo , Brugno Rachele
Published: April 2013

In the last few years the need to produce food with added value has fueled the search for new ingredients and health-promoting compounds. In particular, to improve the quality of bakery products with distinct nutritional properties, the identification of new raw materials, appropriate technologies, and specific microbial strains is necessary. In this study, different doughs were prepared, with 10% and 20% flour from immature wheat grain blended with type “0 America” wheat flour. Immature flour was obtained from durum wheat grains harvested 1 to 2 weeks after anthesis. Doughs were obtained by both the straight-dough and sourdough processes. Two selected exopolysaccharide-producing strains of lactic acid bacteria (LAB),
Leuconostoc lactis
A95 and
Lactobacillus curvatus
69B2, were used as starters. Immature flour contained 2.21 g/100 g (dry weight) of fructo-oligosaccharides. Twenty percent immature flour in dough resulted in a shorter leavening time (4.23 ï¿½ 0.03 h) than with the control and dough with 10% immature flour. The total titratable acidity of sourdough with 20% immature flour was higher (12.75 ï¿½ 0.15 ml 0.1 N NaOH) than in the control and sourdough with 10% immature wheat flour (9.20 ml 0.1 N NaOH). Molecular analysis showed that all samples contained three LAB species identified as
L. lactis
,
L. curvatus
, and
Pediococcus acidilactici
. A larger amount of exopolysaccharide was found in sourdough obtained with 20% immature flour (5.33 ï¿½ 0.032 g/kg), positively influencing the exopolysaccharide content of the bread prepared by the sourdough process (1.70 ï¿½ 0.03 g/kg). The addition of 20% immature flour also led to a greater presence of fructo-oligosaccharides in the bread (900 mg/100 g dry weight), which improved its nutritional characteristics. While bread volume decreased as the concentration of immature wheat flour increased, its mechanical characteristics (stress at a strain of 30%) were the same in all samples obtained with different percentages of fructo-oligosaccharides. These data support the use of immature wheat grain flour, and exopolysaccaride-producing lactic acid bacteria in formulating functional prebiotic baked goods whose nutritional value can be suitably improved.
Molecular Characterization of CTX-M β-Lactamase and Associated Addiction Systems in Escherichia coli Circulating among Cattle, Farm Workers, and the Farm Environment
Authors: Tamang Migma Dorji , Nam Hyang-Mi , Gurung Mamata , Jang Geum-Chan , Kim Su-Ran , Jung Suk-Chan , Park Yong Ho , Lim Suk-Kyung
Published: April 2013

A total of 84 extended-spectrum β-lactamase (ESBL)-producing
Escherichia coli
isolates from cattle, farm workers, and the farm environment isolated from February to September 2008 in the Republic of Korea were investigated. All 84 ESBL-producing isolates carried
bla
CTX-M
genes that belonged to the CTX-M-1 (
n
= 35) or CTX-M-9 (
n
= 49) family. The most predominant CTX-M type identified was CTX-M-14 (
n
= 49), followed by CTX-M-32 (
n
= 26). The
bla
CTX-M
genes were identified most commonly in
E. coli
isolates from feces (
n
= 29), teats (
n
= 25), and milk (
n
= 14). A
bla
CTX-M-14
gene was also detected in an
E. coli
isolate from a farmer's hand. Transfer of the
bla
CTX-M
gene from 60
bla
CTX-M
-positive
E. coli
isolates to the recipient
E. coli
J53 strain by conjugation was demonstrated. Plasmid isolation from
bla
CTX-M
-positive transconjugants revealed a large (95- to 140-kb) conjugative plasmid. Almost all (82/84)
bla
CTX-M
genes possessed an insertion sequence, IS
Ecp1
, upstream of the
bla
CTX-M
gene. Only in the case of the CTX-M-14 genes was IS
903
downstream of the gene. The
bla
CTX-M
genes were associated with seven kinds of addiction systems. Among them,
pndAC
,
hok-sok
, and
srnBC
were the most frequently identified addiction systems in both wild strains and transconjugants. The spread of
bla
CTX-M
genes was attributed to both clonal expansion and horizontal dissemination. Our data suggest that a combination of multiple addiction systems in plasmids carrying
bla
CTX-M
genes could contribute to their maintenance in the host cells. To our knowledge, the
bla
CTX-M-32
gene has not previously been reported in animal isolates from the Republic of Korea.
Characterization of Site-Specific Mutations in a Short-Chain-Length/Medium-Chain-Length Polyhydroxyalkanoate Synthase:
In Vivo
and
In Vitro
Studies of Enzymatic Activity and Substrate Specificity
Authors: Chuah Jo-Ann , Tomizawa Satoshi , Yamada Miwa , Tsuge Takeharu , Doi Yoshiharu , Sudesh Kumar , Numata Keiji
Published: April 2013

Saturation point mutagenesis was carried out at position 479 in the polyhydroxyalkanoate (PHA) synthase from
Chromobacterium
sp. strain USM2 (PhaC
Cs
) with specificities for short-chain-length (SCL) [(
R
)-3-hydroxybutyrate (3HB) and (
R
)-3-hydroxyvalerate (3HV)] and medium-chain-length (MCL) [(
R
)-3-hydroxyhexanoate (3HHx)] monomers in an effort to enhance the specificity of the enzyme for 3HHx. A maximum 4-fold increase in 3HHx incorporation and a 1.6-fold increase in PHA biosynthesis, more than the wild-type synthase, was achieved using selected mutant synthases. These increases were subsequently correlated with improved synthase activity and increased preference of PhaC
Cs
for 3HHx monomers. We found that substitutions with uncharged residues were beneficial, as they resulted in enhanced PHA production and/or 3HHx incorporation. Further analysis led to postulations that the size and geometry of the substrate-binding pocket are determinants of PHA accumulation, 3HHx fraction, and chain length specificity.
In vitro
activities for polymerization of 3HV and 3HHx monomers were consistent with
in vivo
substrate specificities. Ultimately, the preference shown by wild-type and mutant synthases for either SCL (C
4
and C
5
) or MCL (C
6
) substrates substantiates the fundamental classification of PHA synthases.
Identification of Mutations Involved in the Requirement of Potassium for Growth of Typical Melissococcus plutonius Strains
Authors: Takamatsu Daisuke , Arai Rie , Miyoshi-Akiyama Tohru , Okumura Kayo , Okura Masatoshi , Kirikae Teruo , Kojima Atsuko , Osaki Makoto
Published: April 2013

Melissococcus plutonius
is a fastidious honeybee pathogen, and the addition of KH
2
PO
4
to culture medium is required for its growth. Using genome sequences and a newly developed vector, we showed that mutations in genes encoding Na
+
/H
+
antiporter and cation-transporting ATPase are involved in the potassium requirement for growth.
Insights into the Ropy Phenotype of the Exopolysaccharide-Producing Strain Bifidobacterium animalis subsp.
lactis
A1dOxR
Authors: Hidalgo-Cantabrana Claudio , Sï¿½nchez Borja , Moine Deborah , Berger Bernard , de los Reyes-Gavilï¿½n Clara G. , Gueimonde Miguel , Margolles Abelardo , Ruas-Madiedo Patricia
Published: April 2013

The proteome of the ropy strain
Bifidobacterium animalis
subsp.
lactis
A1dOxR, compared to that of its nonropy isogenic strain, showed an overproduction of a protein involved in rhamnose biosynthesis. Results were confirmed by gene expression analysis, and this fact agreed with the high rhamnose content of the ropy exopolysaccharide.
Construction of Mobilizable Mini-Tn
7
Vectors for Bioluminescent Detection of Gram-Negative Bacteria and Single-Copy Promoter
lux
Reporter Analysis
Authors: Damron F. Heath , McKenney Elizabeth S. , Barbier Mariette , Liechti George W. , Schweizer Herbert P. , Goldberg Joanna B.
Published: April 2013

We describe the construction of mini-Tn
7
-based broad-host-range vectors encoding
lux
genes as bioluminescent reporters. These constructs can be mobilized into the desired host(s) by conjugation for chromosomal mini-Tn
7-lux
integration and are useful for localization of bacteria during infections or for characterizing regulation of promoters of interest in Gram-negative bacteria.
Prevalence and Relatedness of Escherichia coli O157:H7 Strains in the Feces and on the Hides and Carcasses of U.S. Meat Goats at Slaughter
Authors: Jacob M. E. , Foster D. M. , Rogers A. T. , Balcomb C. C. , Sanderson M. W.
Published: April 2013

We determined the prevalences of
Escherichia coli
O157:H7 in feces, hide, and carcasses of meat goats at a U.S. processing plant. Prevalences were 11.1%, 2.7%, and 2.7%, respectively. Sixteen pulsed-field gel electrophoresis (PFGE) subtypes were identified among 49
E. coli
O157:H7 isolates, some of which were present on multiple sample types or collection days.
Bioenergetics of the Moderately Halophilic Bacterium Halobacillus halophilus: Composition and Regulation of the Respiratory Chain
Authors: Pade Nadin , Kï¿½cher Saskia , Roeï¿½ler Markus , Hï¿½nelt Inga , Mï¿½ller Volker
Published: April 2013

In their natural environments, moderately halophilic bacteria are confronted not only with high salinities but also with low oxygen tensions due to the high salinities. The growth of
H. halophilus
is strictly aerobic. To analyze the dependence of respiration on the NaCl concentration and oxygen availability of the medium, resting cell experiments were performed. The respiration rates were dependent on the NaCl concentration of the growth medium, as well as on the NaCl concentration of the assay buffer, indicating regulation on the transcriptional and the activity level. Respiration was accompanied by the generation of an electrochemical proton potential (Δμ̃

H
+

) across the cytoplasmic membrane whose magnitude was dependent on the external pH. Genes encoding proteins involved in respiration and Δμ̃

H
+

generation, such as a noncoupled NADH dehydrogenase (NDH-2), complex II, and complex III, were identified in the genome. In addition, genes encoding five different terminal oxidases are present. Inhibitor profiling revealed the presence of NDH-2 and complex III, but the nature of the oxidases could not be resolved using this approach. Expression analysis demonstrated that all the different terminal oxidases were indeed expressed, but by far the most prominent was
cta
, encoding cytochrome
caa
3
oxidase. The expression of all of the different oxidase genes increased at high NaCl concentrations, and the transcript levels of
cta
and
qox
(encoding cytochrome
aa
3
oxidase) also increased at low oxygen concentrations. These data culminate in a model of the composition and variation of the respiratory chain of
H. halophilus
.
ω-Transaminase from Ochrobactrum anthropi Is Devoid of Substrate and Product Inhibitions
Authors: Park Eul-Soo , Shin Jong-Shik
Published: April 2013

ω-Transaminases display complicated inhibitions by ketone products and both enantiomers of amine substrates. Here, we report the first example of ω-transaminase devoid of such inhibitions. Owing to the lack of enzyme inhibitions, the ω-transaminase from
Ochrobactrum anthropi
enabled efficient kinetic resolution of α-methylbenzylamine (500 mM) even without product removal.