bluuebunny/crossref_metadata_2025 huggingface dataset:
Evans syndrome after unrelated bone marrow transplantation for refractory cytopenia of childhood
Authors: Ueki Hideaki , Igarashi Shunji , Kimura Shunsuke , Tsuchimochi Taichiro , Furudate Kazuki , Sakurai Ayako , Noguchi Yasushi , Sunami Shosuke
Published: July 2014

Post‐transplant ES, which is often resistant to therapies, has seldom been described. This report describes a case of ES after UBMT for RCC. A five‐yr‐old boy developed RCC with no evidence of monosomy 7. Because no matching family donors were available for SCT and immunosuppressive therapy was ineffective, UBMT was performed when he was six yr old. The conditioning regimen included TAI (3 Gy) and administration of FLU, CY, and rabbit antithymocyte globulin. The recovery of blood cells was good. He displayed grade II acute GVHD involving only the skin. ES developed on day 66, with positive results for Epstein–Barr virus DNA and HHV 6. Cytopenia was resolved with treatment with RTX, GCV, an escalated dose of steroids, high‐dose gammaglobulin, and romiplostim. No relapse has occurred since discontinuing steroids on day 177 and romiplostim on day 268. Post‐SCT ES after UBMT is rare, and the risk factors and therapies are unclear. Prospective analysis and collection of cases from multiple centers are required for clarification.
Hypericin Damages the Ectatic Capillaries in a Roman Cockscomb Model and Inhibits the Growth of Human Endothelial Cells More Potently Than Hematoporphyrin Does through Induction of Apoptosis
Authors: Li Zhuo‐heng , Meng De‐sheng , Li Yuan‐yuan , Lu Lai‐chun , Yu Cai‐ping , Zhang Qian , Guan Hai‐yan , Li Chen‐wen , Yang Xue , Fu Ruo‐qiu
Published: July 2014

Hypericin (HY) is a promising photosensitizer (PS) for use in photodynamic therapy (PDT). Port‐wine stains (PWSs) are congenital superficial dermal capillary malformations. In this study, we evaluated the photocytotoxic effects of HY for PDT in human vascular endothelial cells and a chicken cockscomb model. HY significantly inhibited the growth of human umbilical vein endothelial cells (HUVECs), as determined by colorimetric assays and morphological observation, and flow cytometry assays indicated induction of apoptosis and collapse of the mitochondrial membrane potential. In addition, HY more effectively inhibited growth of and induced apoptosis in HUVECs compared with hematoporphyrin (HP). Further experiments performed in a Roman chicken cockscomb model also showed a clear photocytotoxic effect on the cockscomb dermal capillary upon intravenous injection of HY. This effect may be due to the role of HY in the induction of apoptosis. Transmission electron microscopical analysis showed mitochondrial morphological changes such as incomplete ridges and swelling, and immunohistochemical assays showed an increase in the release of cytochrome c. In conclusion, HY exhibited a greater photocytotoxic activity than did HP toward the growth of endothelial cells and may thus represent a potent PS for PWS PDT.
Economic Growth and Electricity Consumption in GCC and MENA Countries
Authors: Kayıkçı Fazıl , Bildirici Melike
Published: July 2014

This study estimates the causal relationship between oil rents, electricity consumption and economic growth at aggregate levels with annual data from between 1972 and 2011 for the Arab states of the Gulf and some Middle East and North African countries. An autoregressive distributed lag bounds test shows that oil rents, economic growth and electricity consumption are cointegrated for these countries in a stable manner over this whole period. Granger causality tests indicate that directions of causalities differ for the countries according to their natural resource levels. Thus, these countries can be classified according to their oil rent levels for implementing energy policies such as energy conservation.
Estimates of large magnitude Late Cambrian earthquakes from seismogenic soft‐sediment deformation structures: Central Rocky Mountains
Authors: Myrow Paul M. , Chen Jitao
Published: July 2014

A variety of unusual early post‐depositional deformation structures exist in grainstone and flat‐pebble conglomerate beds of Upper Cambrian strata, western Colorado, including slide scarps, thrusted beds, irregular blocks and internally deformed beds. Thrusted beds up to tens of centimetres thick record thrust movement of a part of a bed onto itself along a moderate to steeply inclined (15° to 40°) ramp, locally producing hanging wall lenses with fault‐bend geometries. Thrust plane orientations are widely distributed, and in some cases nearly oppositely oriented in close proximity, indicating that they did not form as failures acted upon by gravity forces. Irregular bedded to internally deformed blocks are isolated on generally flat upper bedding surfaces. These features represent parts of beds that detached, moved up onto and some distances across, the laterally adjacent undisturbed bed surfaces. Deformation of thin intervals of mud on the ocean floor by moving blocks rules out the possibility of storm‐induced deformation, because the mud was not eroded by high shear stresses that would accompany the extremely large forces required to produce and move the blocks. Finally, internally deformed beds are characterized by large blocks, fitted fabrics of highly irregular fragments and contorted lamination, which represent heterogeneous deformation, such as brecciation and liquefaction. The deformation structures were produced by earthquakes linked to the reactivation of Mesoproterozoic, crustal‐scale shear zones in the central Rockies during the Late Cambrian. Analysis of the deformation structures indicates very large body forces and calculated earthquake‐generated ground motion velocities of ca 1·6 m sec−1. These correspond to moment magnitudes of ca 7·0 or more and a Mercalli Intensity of X+. These are the only known magnitude estimates of Phanerozoic (other than Quaternary) large‐intensity earthquakes for the Rocky Mountain region, and they are as large as, or larger than, previous estimates of Proterozoic earthquakes along these major shear zones of the central Rockies.
Patients with tattoo reactions have reduced quality of life and suffer from itch
Authors: Hutton Carlsen K. , Serup J.
Published: July 2014

Background

Tattoos are a trend with increasing side‐effects. The burden of local reaction with swelling, itching and discomfort may impel sufferers to consult medical assistance.

Objectives

To assess tattoo reactions and their influence on quality of life and itching by utilizing the Dermatology Life Quality Index (DLQI) scoring system and Itch Severity Scale (ISS).

Methods

Patients attending the ‘Tattoo Clinic’ at Bispebjerg University Hospital, Denmark with tattoo problems spanning more than 3 months were invited. Forty patients participated during September–November 2012. Patients attending their routine consultations completed the ISS and DLQI questionnaires.

Results

Patients with tattoo reactions experienced reduced quality of life, DLQI score 7.4 and were burdened by itch, ISS score 7.2. Both DLQI and ISS results attained the level of discomfort of known skin diseases such as psoriasis, pruritus and eczema albeit the typical tattooed affected areas are smaller.

Conclusion/Discussion

Sufferers of tattoo reactions have reduced quality of life and are often burdened by itching attaining the level of other cumbersome afflictions recognized as dermatological diseases associated with itch. Tattoo reactions warrant diagnosis and treatment with same professional intent shared with other skin diseases.
Non‐invasive assessment of cutaneous wound healing using fluorescent imaging
Authors: Lee O. , Kim J. , Park G. , Kim M. , Son S. , Ha S. , Oh C.
Published: July 2014

Background/purpose

Optical imaging is a very important technique in the biomedical sciences. The purpose of this study was to develop an in vivo optical system for fluorescent imaging and molecular imaging applications using quantum dots (QDs).

Methods

The in vivo optical system was composed of modular parts, including a light source, light guide, excitation filter wheel, excitation filters, emission filter wheel, emission filters, liquid crystal tunable filter (LCTF), macro lens, dark chamber, and a cooled charged‐coupled device (CCD) camera for recording images. Filters were selected based on the excitation and absorption spectra of QDs to allow spectral separation and optimization of the acquired image. In contrast with conventional systems, our system allows selection of the emission bandwidth.

Results

The system was tested in an in vivo study using a wound‐healing model in nude mice. The healing process was examined after injection of fibroblasts and keratinocytes labeled with two different sets of QDs. The different QD probes were readily detected and distinguished using our system.

Conclusion

An in vivo optical system is a very useful tool for the detection of genes, proteins, and small‐molecule drugs inside living animals, and this imaging modality can also be adopted for real‐time visualization of cancer cell metastasis in live animals.
The effects of water exposure on biophysical properties of normal skin
Authors: Firooz A. , Aghazadeh N. , Rajabi Estarabadi A. , Hejazi P.
Published: July 2014

Background

Water exposure is an influential factor in some common dermatoses. It has also been shown that water has an effect on barrier function and biophysical properties of skin. The aim of this study was to evaluate the effect of water immersion on biophysical properties of normal skin.

Participants & methods

Twenty healthy volunteers participated in this study. The volar aspect of volunteer's forearm was immersed in tap water for 30 min a day for five consecutive days. Biophysical skin parameters including TEWL, skin pH, capacitance, erythema and sebum content were measured using specific probes before and after the exposure and compared with unexposed other forearm as control.

Results

TEWL and pH of the exposed forearm increased significantly after 5 days of consecutive daily exposure to water.

Conclusion

Water exposure increases the TEWL and pH of normal skin. Future studies evaluating the durability of the increased TEWL through monitoring the time course of events following skin immersion in water and susceptibility of skin to chemical irritants are required.
Effects of two different anesthetic protocols on 64‐MDCT coronary angiography in dogs
Authors: Drees Randi , Johnson Rebecca A. , Pinkerton Marie , Del Rio Alejandro Munoz , Saunders Jimmy H. , François Christopher J.
Published: July 2014

Heart rate is a major factor influencing diagnostic image quality in computed tomographic coronary artery angiography (MDCT‐CA), with an ideal heart rate of 60–65 beats/min in humans. The purpose of this prospective study was to compare effects of two different clinically applicable anesthetic protocols on cardiovascular parameters and 64‐MDCT‐CA quality in 10 healthy dogs. Scan protocols and bolus volumes were standardized. Image evaluations were performed in random order by a board‐certified veterinary radiologist who was unaware of anesthetic protocols used. Heart rate during image acquisition did not differ between protocols (P= 1), with 80.6 ± 7.5 bpm for protocol A and 79.2 ± 14.2 bpm for protocol B. Mean blood pressure was significantly higher (P> 0.05) using protocol B (protocol A 62.9 ± 9.1 vs. protocol B 72.4 ± 15.9 mmHg). The R‐R intervals allowing for best depiction of individual coronary artery segments were found in the end diastolic period and varied between the 70% and 95% interval. Diagnostic quality was rated excellent, good, and moderate in the majority of the segments evaluated, with higher scores given for more proximal segments and lower for more distal segments, respectively. Blur was the most commonly observed artifact and mainly affected the distal segments. No significant differences were identified between the two protocols for optimal reconstruction interval, diagnostic quality and measured length individual segments, or proximal diameter of the coronary arteries (P= 1). Findings indicated that, when used with a standardized bolus volume, both of these anesthetic protocols yielded diagnostic quality coronary 64‐MDCT‐CA exams in healthy dogs.
Increased cardiac output contributes to the development of chronic intermittent hypoxia‐induced hypertension
Authors: Lucking Eric F. , O'Halloran Ken D. , Jones James F. X.
Published: July 2014

New Findings

What is the central question of this study?

Chronic intermittent hypoxia (CIH)‐induced hypertension is commonly believed to be a consequence of sympathetic nervous system hyperactivity, but direct recordings of chronic vasoconstriction have never been performed hitherto. We determined whether chronic vasoconstriction contributes to the development of hypertension in CIH‐exposed animals.

What is the main finding and its importance?

We found no evidence of chronic vasoconstriction in CIH‐exposed rats; instead, the development of hypertension was due to an increase in cardiac output. This attempt to increase O2 flow may lead to the initial development of hypertension. Increased in cardiac output has never been previously reported and could be an important parameter to measure in sleep apnoea patients.

Chronic intermittent hypoxia (CIH) in animal models has been shown to result in hypertension and elevation of sympathetic nervous system activity. Sympathetically mediated vasoconstriction is believed to be the primary mechanism underpinning CIH‐induced hypertension; however, the potential contribution of the heart is largely overlooked. We sought to determine the contribution of cardiac output (CO) and lumbar sympathetic control of the hindlimb circulation to CIH‐induced hypertension. Male Wistar rats (n = 64) were exposed to 2 weeks of CIH [cycles of 90 s hypoxia (5% O2 nadir) and 210 s normoxia] or normoxia for 8 h day−1. Under urethane anaesthesia, CIH‐treated animals developed hypertension (81.4 ± 2.2 versus 91.6 ± 2.4 mmHg; P < 0.001), tachycardia (397 ± 8 versus 445 ± 7 beats min−1; P < 0.001) and an increased haematocrit (42.4 ± 0.4 versus 45.0 ± 0.4%; P < 0.001). Echocardiography revealed that CIH exposure increased the CO [19.3 ± 1.7 versus 25.8 ± 2.6 ml min−1 (100 g)−1; P = 0.027] with no change in total peripheral resistance (4.93 ± 0.49 versus 4.17 ± 0.34 mmHg ml−1 min−1; P = 0.123). Sympathetic ganglionic blockade revealed that sympathetic control over blood pressure was not different (−27.7 ± 1.6 versus −32.3 ± 2.9 mmHg; P = 0.095), and no chronic vasoconstriction was found in the hindlimb circulation of CIH‐treated animals (39.4 ± 2.5 versus 38.0 ± 2.4 μl min−1 mmHg−1; P = 0.336). Lumbar sympathetic control over the hindlimb circulation was unchanged in CIH‐treated animals (P = 0.761), although hindlimb arterial sympathetic density was increased (P = 0.012) and vascular sensitivity to phenylephrine was blunted (P = 0.049). We conclude that increased CO is sufficient to explain the development of CIH‐induced hypertension, which may be an early adaptive response to raise O2 flow. We propose that sustained elevated cardiac work may ultimately lead to heart failure.
Breath‐by‐breath pulmonary O2 uptake kinetics: effect of data processing on confidence in estimating model parameters
Authors: Keir Daniel A. , Murias Juan M. , Paterson Donald H. , Kowalchuk John M.
Published: July 2014

New Findings

What is the central question of this study?

In groups of young and older adults, we investigated whether techniques used as common practice for processing breath‐by‐breath pulmonary O2 uptake data from repeated step transitions in work rate into the moderate‐intensity exercise domain influence the model parameter estimations and confidence of describing the phase II pulmonary O2 uptake response.

What is the main finding and its importance?

Results demonstrate that regardless of age group, during transitions into the moderate‐intensity exercise domain, techniques for processing individual transitions did not affect parameter estimates describing the phase II pulmonary O2 uptake response; however, the confidence in the parameter estimation could be improved by the technique used to process individual trials.

To improve the signal‐to‐noise ratio of breath‐by‐breath pulmonary O2 uptake () data, it is common practice to perform multiple step transitions, which are subsequently processed to yield an ensemble‐averaged profile. The effect of different data‐processing techniques on phase II kinetic parameter estimates ( amplitude, time delay and phase II time constant (τ)] and model confidence [95% confidence interval (CI95)] was examined. Young (n = 9) and older men (n = 9) performed four step transitions from a 20 W baseline to a work rate corresponding to 90% of their estimated lactate threshold on a cycle ergometer. Breath‐by‐breath was measured using mass spectrometry and volume turbine. Mono‐exponential kinetic modelling of phase II data was performed on data processed using the following techniques: (A) raw data (trials time aligned, breaths of all trials combined and sorted in time); (B) raw data plus interpolation (trials time aligned, combined, sorted and linearly interpolated to second by second); (C) raw data plus interpolation plus 5 s bin averaged; (D) individual trial interpolation plus ensemble averaged [trials time aligned, linearly interpolated to second by second (technique 1; points joined by straight‐line segments), ensemble averaged]; (E) ‘D’ plus 5 s bin averaged; (F) individual trial interpolation plus ensemble averaged [trials time aligned, linearly interpolated to second by second (technique 2; points copied until subsequent point appears), ensemble averaged]; and (G) ‘F’ plus 5 s bin averaged. All of the model parameters were unaffected by data‐processing technique; however, the CI95 for τ in condition ‘D’ (4 s) was lower (P < 0.05) than the CI95 reported for all other conditions (5–10 s). Data‐processing technique had no effect on parameter estimates of the phase II response. However, the narrowest interval for CI95 occurred when individual trials were linearly interpolated and ensemble averaged.
P3GA: An Algorithm for Technology Characterization
Authors: Galvan Edgar , Malak Richard J.
Published: July 2014

It is important for engineers to understand the capabilities and limitations of the technologies they consider for use in their systems. However, communicating this information can be a challenge. Mathematical characterizations of technical capabilities are of interest as a means to reduce ambiguity in communication and to increase opportunities to utilize design automation methods. The parameterized Pareto frontier (PPF) was introduced in prior work as a mathematical basis for modeling technical capabilities. One advantage of PPFs is that, in many cases, engineers can model a system by composing frontiers of its components. This allows for rapid technology evaluation and design space exploration. However, finding the PPF can be difficult. The contribution of this article is a new algorithm for approximating the PPF, called predictive parameterized Pareto genetic algorithm (P3GA). The proposed algorithm uses concepts and methods from multi-objective genetic optimization and machine learning to generate a discrete approximation of the PPF. If needed, designers can generate a continuous approximation of the frontier by generalizing beyond these data. The algorithm is explained, its performance is analyzed on numerical test problems, and its use is demonstrated on an engineering example. The results of the investigation indicate that P3GA may be effective in practice.
Machine Learning Algorithms for Recommending Design Methods
Authors: Fuge Mark , Peters Bud , Agogino Alice
Published: July 2014

Every year design practitioners and researchers develop new methods for understanding users and solving problems. This increasingly large collection of methods causes a problem for novice designers: How does one choose which design methods to use for a given problem? Experienced designers can provide case studies that document which methods they used, but studying these cases to infer appropriate methods for a novel problem is inefficient. This research addresses that issue by applying techniques from content-based and collaborative filtering to automatically recommend design methods, given a particular problem. Specifically, we demonstrate the quality with which different algorithms recommend 39 design methods out of an 800+ case study dataset. We find that knowing which methods occur frequently together allows one to recommend design methods more effectively than just using the text of the problem description itself. Furthermore, we demonstrate that automatically grouping frequently co-occurring methods using spectral clustering replicates human-provided groupings to 92% accuracy. By leveraging existing case studies, recommendation algorithms can help novice designers efficiently navigate the increasing array of design methods, leading to more effective product design.
High Rotation Rate Behavior of Cervical Spine Segments in Flexion and Extension
Authors: Barker Jeffrey B. , Cronin Duane S. , Chandrashekar Naveen
Published: July 2014

Numerical finite element (FE) models of the neck have been developed to simulate occupant response and predict injury during motor vehicle collisions. However, there is a paucity of data on the response of young cervical spine segments under dynamic loading in flexion and extension, which is essential for the development or validation of tissue-level FE models. This limitation was identified during the development and validation of the FE model used in this study. The purpose of this study was to measure the high rotation rate loading response of human cervical spine segments in flexion and extension, and to investigate a new tissue-level FE model of the cervical spine with the experimental data to address a limitation in available data. Four test samples at each segment level from C2–C3 to C7–T1 were dissected from eight donors and were tested to 10 deg of rotation at 1 and 500 deg/s in flexion and extension using a custom built test apparatus. There was strong evidence (p < 0.05) of increased stiffness at the higher rotation rate above 4 deg of rotation in flexion and at 8 deg and 10 deg of rotation in extension. Cross-correlation software, Cora, was used to evaluate the fit between the experimental data and model predictions. The average rating was 0.771, which is considered to demonstrate a good correlation to the experimental data.
Numerical Analysis of Heat Transfer and Pressure Drop in Metal Foams for Different Morphological Models
Authors: Iasiello Marcello , Cunsolo Salvatore , Oliviero Maria , Harris William M. , Bianco Nicola , Chiu Wilson K. S. , Naso Vincenzo
Published: July 2014

Because of their light weight, open porosity, high surface area per unit volume, and thermal characteristics, metal foams are a promising material for many industrial applications involving fluid flow and heat transfer. The pressure drop and heat transfer in porous media have inspired a number of experimental and numerical studies, and many models have been proposed in the literature that correlate the pressure gradient and the heat transfer coefficient with the mean cell size and porosity. However, large differences exist among results predicted by different models, and most studies are based on idealized periodic cell structures. In this study, the true three-dimensional microstructure of the metal foam is obtained by employing x-ray computed microtomography (XCT). This is the “real” structure. For comparison, ideal Kelvin foam structures are developed in the free-to-use software “surface evolver” surface energy minimization program. These are “ideal” structures. Pressure drop and heat transfer are then investigated in each structure using the CFD module of COMSOL® Multiphysics code. A comparison between the numerical predictions from the real and ideal geometries is carried out. The predictions showed that heat transfer characteristics are very close for low values of Reynolds number, but larger Reynolds numbers create larger differences between the results of the ideal and real structures. Conversely, the differences in pressure drop at any Reynolds number are nearly 100%. Results from the models are then validated by comparing them with experimental results taken from the literature. The validation suggests that the ideal structure poorly predicts the heat transfer and pressure drops.
ZnO nanorod growth by plasma-enhanced vapor phase transport with different growth durations
Authors: Kim Chang-Yong , Oh Hee-bong , Ryu Hyukhyun , Yun Jondo , Lee Won-Jae
Published: July 2014

In this study, the structural properties of ZnO nanostructures grown by plasma-enhanced vapor phase transport (PEVPT) were investigated. Plasma-treated oxygen gas was used as the oxygen source for the ZnO growth. The structural properties of ZnO nanostructures grown for different durations were measured by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The authors comprehensively analyzed the growth of the ZnO nanostructures with different growth durations both with and without the use of plasma-treated oxygen gas. It was found that PEVPT has a significant influence on the growth of the ZnO nanorods. PEVPT with plasma-treated oxygen gas facilitated the generation of nucleation sites, and the resulting ZnO nanorod structures were more vertical than those prepared by conventional VPT without plasma-treated oxygen gas. As a result, the ZnO nanostructures grown using PEVPT showed improved structural properties compared to those prepared by the conventional VPT method.
Rab13 acts downstream of the kinase Mst1 to deliver the integrin LFA-1 to the cell surface for lymphocyte trafficking
Authors: Nishikimi Akihiko , Ishihara Sayaka , Ozawa Madoka , Etoh Kan , Fukuda Mitsunori , Kinashi Tatsuo , Katagiri Koko
Published: July 2014

Chemokines promote the delivery and proper organization of an integrin at the leading edge of migrating lymphocytes.
The COP II adaptor protein TMED7 is required to initiate and mediate the delivery of TLR4 to the plasma membrane
Authors: Liaunardy-Jopeace Ardiyanto , Bryant Clare E. , Gay Nicholas J.
Published: July 2014

Without the protein TMED7, the immune receptor TLR4 cannot reach the cell surface but exhibits ligand-independent signaling from the inside.
Science Signaling
Podcast: 29 July 2014
Authors: Gay Nicholas J. , VanHook Annalisa M.
Published: July 2014

The adaptor protein TMED7 targets the pathogen-sensing receptor TLR4 to the plasma membrane.
“miR”roring Lupus Control
Authors: Colmone Angela
Published: July 2014

Decreased expression of PTEN regulated by miR-7 contributes to B cell hyperresponsiveness and disturbed B cell homeostasis in SLE.
Changing Antimicrobial Resistance Profiles among Neisseria gonorrhoeae Isolates in Italy, 2003 to 2012
Authors: Carannante Anna , Renna Giovanna , Dal Conte Ivano , Ghisetti Valeria , Matteelli Alberto , Prignano Grazia , Impara Giampaolo , Cusini Marco , D'Antuono Antonietta , Vocale Caterina , Antonetti Raffaele , Gaino Marina , Busetti Marina , Latino Maria Agnese , Mencacci Antonella , Bonanno Carmen , Cava Maria Carmela , Giraldi Cristina , Stefanelli Paola
Published: July 2014

The emergence of
Neisseria gonorrhoeae
isolates displaying resistance to antimicrobial agents is a major public health concern and a serious issue related to the occurrence of further untreatable gonorrhea infections. A retrospective analysis on 1,430
N. gonorrhoeae
isolates, collected from 2003 through 2012, for antimicrobial susceptibility by Etest and molecular characterization by
Neisseria gonorrhoeae
multiantigen sequence typing (NG-MAST) was carried out in Italy. Azithromycin-resistant gonococci decreased from 14% in 2007 to 2.2% in 2012. Similarly, isolates with high MICs to cefixime (>0.125 mg/liter) decreased from 11% in 2008 to 3.3% in 2012. The ciprofloxacin resistance rate remains quite stable, following an increasing trend up to 64% in 2012. The percentage of penicillinase-producing
N. gonorrhoeae
(PPNG) significantly declined from 77% in 2003 to 7% in 2012. A total of 81 multidrug-resistant (MDR) gonococci were identified, showing 11 different antimicrobial resistance patterns. These were isolated from men who have sex with men (MSM) and from heterosexual patients. Two sequence types (STs), ST661 and ST1407, were the most common. Genogroup 1407, which included cefixime-, ciprofloxacin-, and azithromycin-resistant isolates, was found. In conclusion, a change in the antimicrobial resistance profiles among gonococci was identified in Italy together with a percentage of MDR isolates.
Extensively Drug-Resistant Pseudomonas aeruginosa Isolates Containing
bla
VIM-2
and Elements of Salmonella Genomic Island 2: a New Genetic Resistance Determinant in Northeast Ohio
Authors: Perez Federico , Hujer Andrea M. , Marshall Steven H. , Ray Amy J. , Rather Philip N. , Suwantarat Nuntra , Dumford Donald , O'Shea Patrick , Domitrovic T. Nicholas J. , Salata Robert A. , Chavda Kalyan D. , Chen Liang , Kreiswirth Barry N. , Vila Alejandro J. , Haussler Susanne , Jacobs Michael R. , Bonomo Robert A.
Published: July 2014

Carbapenems are a mainstay of treatment for infections caused by
Pseudomonas aeruginosa
. Carbapenem resistance mediated by metallo-β-lactamases (MBLs) remains uncommon in the United States, despite the worldwide emergence of this group of enzymes. Between March 2012 and May 2013, we detected MBL-producing
P. aeruginosa
in a university-affiliated health care system in northeast Ohio. We examined the clinical characteristics and outcomes of patients, defined the resistance determinants and structure of the genetic element harboring the
bla
MBL
gene through genome sequencing, and typed MBL-producing
P. aeruginosa
isolates using pulsed-field gel electrophoresis (PFGE), repetitive sequence-based PCR (rep-PCR), and multilocus sequence typing (MLST). Seven patients were affected that were hospitalized at three community hospitals, a long-term-care facility, and a tertiary care center; one of the patients died as a result of infection. Isolates belonged to sequence type 233 (ST233) and were extensively drug resistant (XDR), including resistance to all fluoroquinolones, aminoglycosides, and β-lactams; two isolates were nonsusceptible to colistin. The
bla
MBL
gene was identified as
bla
VIM-2
contained within a class 1 integron (In559), similar to the cassette array previously detected in isolates from Norway, Russia, Taiwan, and Chicago, IL. Genomic sequencing and assembly revealed that In559 was part of a novel 35-kb region that also included a Tn
501
-like transposon and
Salmonella
genomic island 2 (SGI2)-homologous sequences. This analysis of XDR strains producing VIM-2 from northeast Ohio revealed a novel recombination event between
Salmonella
and
P. aeruginosa
, heralding a new antibiotic resistance threat in this region's health care system.
Reduction of Legionella spp. in Water and in Soil by a Citrus Plant Extract Vapor
Authors: Laird Katie , Kurzbach Elena , Score Jodie , Tejpal Jyoti , Chi Tangyie George , Phillips Carol
Published: July 2014

Legionnaires' disease is a severe form of pneumonia caused by
Legionella
spp., organisms often isolated from environmental sources, including soil and water.
Legionella
spp. are capable of replicating intracellularly within free-living protozoa, and once this has occurred,
Legionella
is particularly resistant to disinfectants. Citrus essential oil (EO) vapors are effective antimicrobials against a range of microorganisms, with reductions of 5 log cells ml
−1
on a variety of surfaces. The aim of this investigation was to assess the efficacy of a citrus EO vapor against
Legionella
spp. in water and in soil systems. Reductions of viable cells of
Legionella pneumophila
,
Legionella longbeachae
,
Legionella bozemanii
, and an intra-amoebal culture of
Legionella pneumophila
(water system only) were assessed in soil and in water after exposure to a citrus EO vapor at concentrations ranging from 3.75 mg/liter air to 15g/liter air. Antimicrobial efficacy via different delivery systems (passive and active sintering of the vapor) was determined in water, and gas chromatography-mass spectrometry (GC-MS) analysis of the antimicrobial components (linalool, citral, and β-pinene) was conducted. There was up to a 5-log cells ml
−1
reduction in
Legionella
spp. in soil after exposure to the citrus EO vapors (15 mg/liter air). The most susceptible strain in water was
L. pneumophila
, with a 4-log cells ml
−1
reduction after 24 h via sintering (15 g/liter air). Sintering the vapor through water increased the presence of the antimicrobial components, with a 61% increase of linalool. Therefore, the appropriate method of delivery of an antimicrobial citrus EO vapor may go some way in controlling
Legionella
spp. from environmental sources.
Urea Uptake and Carbon Fixation by Marine Pelagic Bacteria and Archaea during the Arctic Summer and Winter Seasons
Authors: Connelly Tara L. , Baer Steven E. , Cooper Joshua T. , Bronk Deborah A. , Wawrik Boris
Published: July 2014

How Arctic climate change might translate into alterations of biogeochemical cycles of carbon (C) and nitrogen (N) with respect to inorganic and organic N utilization is not well understood. This study combined
15
N uptake rate measurements for ammonium, nitrate, and urea with
15
N- and
13
C-based DNA stable-isotope probing (SIP). The objective was to identify active bacterial and archeal plankton and their role in N and C uptake during the Arctic summer and winter seasons. We hypothesized that bacteria and archaea would successfully compete for nitrate and urea during the Arctic winter but not during the summer, when phytoplankton dominate the uptake of these nitrogen sources. Samples were collected at a coastal station near Barrow, AK, during August and January. During both seasons, ammonium uptake rates were greater than those for nitrate or urea, and nitrate uptake rates remained lower than those for ammonium or urea. SIP experiments indicated a strong seasonal shift of bacterial and archaeal N utilization from ammonium during the summer to urea during the winter but did not support a similar seasonal pattern of nitrate utilization. Analysis of 16S rRNA gene sequences obtained from each SIP fraction implicated marine group I
Crenarchaeota
(MGIC) as well as
Betaproteobacteria
,
Firmicutes
, SAR11, and SAR324 in N uptake from urea during the winter. Similarly,
13
C SIP data suggested dark carbon fixation for MGIC, as well as for several proteobacterial lineages and the
Firmicutes
. These data are consistent with urea-fueled nitrification by polar archaea and bacteria, which may be advantageous under dark conditions.
Galactosyl-Lactose Sialylation Using Trypanosoma cruzi trans-Sialidase as the Biocatalyst and Bovine κ-Casein-Derived Glycomacropeptide as the Donor Substrate
Authors: Wilbrink Maarten H. , ten Kate Geert A. , van Leeuwen Sander S. , Sanders Peter , Sallomons Erik , Hage Johannes A. , Dijkhuizen Lubbert , Kamerling Johannis P.
Published: July 2014

trans
-Sialidase (TS) enzymes catalyze the transfer of sialyl (Sia) residues from Sia(α2-3)Gal(β1-
x
)-glycans (sialo-glycans) to Gal(β1-
x
)-glycans (asialo-glycans). Aiming to apply this concept for the sialylation of linear and branched (Gal)

n

Glc oligosaccharide mixtures (GOS) using bovine κ-casein-derived glycomacropeptide (GMP) as the sialic acid donor, a kinetic study has been carried out with three components of GOS, i.e., 3′-galactosyl-lactose (β3′-GL), 4′-galactosyl-lactose (β4′-GL), and 6′-galactosyl-lactose (β6′-GL). This prebiotic GOS is prepared from lactose by incubation with suitable β-galactosidases, whereas GMP is a side-stream product of the dairy industry. The
trans
-sialidase from
Trypanosoma cruzi
(TcTS) was expressed in
Escherichia coli
and purified. Its temperature and pH optima were determined to be 25°C and pH 5.0, respectively. GMP [sialic acid content, 3.6% (wt/wt);
N
-acetylneuraminic acid (Neu5Ac), >99%; (α2-3)-linked Neu5Ac, 59%] was found to be an efficient sialyl donor, and up to 95% of the (α2-3)-linked Neu5Ac could be transferred to lactose when a 10-fold excess of this acceptor substrate was used. The products of the TcTS-catalyzed sialylation of β3′-GL, β4′-GL, and β6′-GL, using GMP as the sialic acid donor, were purified, and their structures were elucidated by nuclear magnetic resonance spectroscopy. Monosialylated β3′-GL and β4′-GL contained Neu5Ac connected to the terminal Gal residue; however, in the case of β6′-GL, TcTS was shown to sialylate the 3 position of both the internal and terminal Gal moieties, yielding two different monosialylated products and a disialylated structure. Kinetic analyses showed that TcTS had higher affinity for the GL substrates than lactose, while the
V
max
and
k
cat
values were higher in the case of lactose.
GH51 Arabinofuranosidase and Its Role in the Methylglucuronoarabinoxylan Utilization System in Paenibacillus sp. Strain JDR-2
Authors: Sawhney Neha , Preston James F.
Published: July 2014

Methylglucuronoarabinoxylan (MeGAX

n

) from agricultural residues and energy crops is a significant yet underutilized biomass resource for production of biofuels and chemicals. Mild thermochemical pretreatment of bagasse yields MeGAX

n

requiring saccharifying enzymes for conversion to fermentable sugars. A xylanolytic bacterium,
Paenibacillus
sp. strain JDR-2, produces an extracellular cell-associated GH10 endoxylanse (XynA
1
) which efficiently depolymerizes methylglucuronoxylan (MeGX

n

) from hardwoods coupled with assimilation of oligosaccharides for further processing by intracellular GH67 α-glucuronidase, GH10 endoxylanase, and GH43 β-xylosidase. This process has been ascribed to genes that comprise a xylan utilization regulon that encodes XynA
1
and includes a gene cluster encoding transcriptional regulators, ABC transporters, and intracellular enzymes that convert assimilated oligosaccharides to fermentable sugars. Here we show that
Paenibacillus
sp. JDR-2 utilized MeGAX

n

without accumulation of oligosaccharides in the medium. The
Paenibacillus
sp. JDR-2 growth rate on MeGAX

n

was 3.1-fold greater than that on oligosaccharides generated from MeGAX

n

by XynA
1
. Candidate genes encoding GH51 arabinofuranosidases with potential roles were identified. Following growth on MeGAX

n

, quantitative reverse transcription-PCR identified a cluster of genes encoding a GH51 arabinofuranosidase (AbfB) and transcriptional regulators which were coordinately expressed along with the genes comprising the xylan utilization regulon. The action of XynA
1
on MeGAX

n

generated arabinoxylobiose, arabinoxylotriose, xylobiose, xylotriose, and methylglucuronoxylotriose. Recombinant AbfB processed arabinoxylooligosaccharides to xylooligosaccharides and arabinose. MeGAX

n

processing by
Paenibacillus
sp. JDR-2 may be achieved by extracellular depolymerization by XynA
1
coupled to assimilation of oligosaccharides and further processing by intracellular enzymes, including AbfB.
Paenibacillus
sp. JDR-2 provides a GH10/GH67 system complemented with genes encoding intracellular GH51 arabinofuranosidases for efficient utilization of MeGAX

n

.
Acetoin Synthesis Acquisition Favors Escherichia coli Growth at Low pH
Authors: Vivijs Bram , Moons Pieter , Aertsen Abram , Michiels Chris W.
Published: July 2014

Some members of the family
Enterobacteriaceae
ferment sugars via the mixed-acid fermentation pathway. This yields large amounts of acids, causing strong and sometimes even lethal acidification of the environment. Other family members employ the 2,3-butanediol fermentation pathway, which generates comparatively less acidic and more neutral end products, such as acetoin and 2,3-butanediol. In this work, we equipped
Escherichia coli
MG1655 with the
budAB
operon, encoding the acetoin pathway, from
Serratia plymuthica
RVH1 and investigated how this affected the ability of
E. coli
to cope with acid stress during growth. Acetoin fermentation prevented lethal medium acidification by
E. coli
in lysogeny broth (LB) supplemented with glucose. It also supported growth and higher stationary-phase cell densities in acidified LB broth with glucose (pH 4.10 to 4.50) and in tomato juice (pH 4.40 to 5.00) and reduced the minimal pH at which growth could be initiated. On the other hand, the acetoin-producing strain was outcompeted by the nonproducer in a mixed-culture experiment at low pH, suggesting a fitness cost associated with acetoin production. Finally, we showed that acetoin production profoundly changes the appearance of
E. coli
on several diagnostic culture media. Natural
E. coli
strains that have laterally acquired
budAB
genes may therefore have escaped detection thus far. This study demonstrates the potential importance of acetoin fermentation in the ecology of
E. coli
in the food chain and contributes to a better understanding of the microbiological stability and safety of acidic foods.
Lactobacillus reuteri 100-23 Modulates Urea Hydrolysis in the Murine Stomach
Authors: Wilson Charlotte M. , Loach Diane , Lawley Blair , Bell Tracey , Sims Ian M. , O'Toole Paul W. , Zomer Aldert , Tannock Gerald W.
Published: July 2014

Comparisons of
in vivo
(mouse stomach) and
in vitro
(laboratory culture) transcriptomes of
Lactobacillus reuteri
strain 100-23 were made by microarray analysis. These comparisons revealed the upregulation of genes associated with acid tolerance, including urease production, in the mouse stomach. Inactivation of the
ureC
gene reduced the acid tolerance of strain 100-23
in vitro
, and the mutant was outcompeted by the wild type in the gut of ex-
Lactobacillus
-free mice. Urine analysis showed that stable isotope-labeled urea, administered by gavage, was metabolized to a greater extent in
Lactobacillus
-free mice than animals colonized by strain 100-23. This surprising observation was associated with higher levels of urease activity and fecal-type bacteria in the stomach digesta of
Lactobacillus
-free mice. Despite the modulation of urea hydrolysis in the stomach, recycling of urea nitrogen in the murine host was not affected since the essential amino acid isoleucine, labeled with a stable isotope, was detected in the livers of both
Lactobacillus
-free and 100-23-colonized animals. Therefore, our experiments reveal a new and unexpected impact of
Lactobacillus
colonization on urea hydrolysis in the murine gut.
Polyamine Transporters and Polyamines Increase Furfural Tolerance during Xylose Fermentation with Ethanologenic Escherichia coli Strain LY180
Authors: Geddes Ryan D. , Wang Xuan , Yomano Lorraine P. , Miller Elliot N. , Zheng Huabao , Shanmugam Keelnatham T. , Ingram Lonnie O.
Published: July 2014

Expression of genes encoding polyamine transporters from plasmids and polyamine supplements increased furfural tolerance (growth and ethanol production) in ethanologenic
Escherichia coli
LY180 (in AM1 mineral salts medium containing xylose). This represents a new approach to increase furfural tolerance and may be useful for other organisms. Microarray comparisons of two furfural-resistant mutants (EMFR9 and EMFR35) provided initial evidence for the importance of polyamine transporters. Each mutant contained a single polyamine transporter gene that was upregulated over 100-fold (microarrays) compared to that in the parent LY180, as well as a mutation that silenced the expression of
yqhD
. Based on these genetic changes, furfural tolerance was substantially reconstructed in the parent, LY180. Deletion of
potE
in EMFR9 lowered furfural tolerance to that of the parent. Deletion of
potE
and
puuP
in LY180 also decreased furfural tolerance, indicating functional importance of the native genes. Of the 8 polyamine transporters (18 genes) cloned and tested, half were beneficial for furfural tolerance (PotE, PuuP, PlaP, and PotABCD). Supplementing AM1 mineral salts medium with individual polyamines (agmatine, putrescine, and cadaverine) also increased furfural tolerance but to a smaller extent. In pH-controlled fermentations, polyamine transporter plasmids were shown to promote the metabolism of furfural and substantially reduce the time required to complete xylose fermentation. This increase in furfural tolerance is proposed to result from polyamine binding to negatively charged cellular constituents such as nucleic acids and phospholipids, providing protection from damage by furfural.
PafR, a Novel Transcription Regulator, Is Important for Pathogenesis in Uropathogenic Escherichia coli
Authors: Baum Mordechai , Watad Mobarak , Smith Sara N. , Alteri Christopher J. , Gordon Noa , Rosenshine Ilan , Mobley Harry L. , Amster-Choder Orna
Published: July 2014

The
metV
genomic island in the chromosome of uropathogenic
Escherichia coli
(UPEC) encodes a putative transcription factor and a sugar permease of the phosphotransferase system (PTS), which are predicted to compose a Bgl-like sensory system. The presence of these two genes, hereby termed
pafR
and
pafP
, respectively, has been previously shown to correlate with isolates causing clinical syndromes. We show here that deletion of both genes impairs the ability of the resulting mutant to infect the CBA/J mouse model of ascending urinary tract infection compared to that of the parent strain, CFT073. Expressing the two genes in
trans
in the two-gene knockout mutant complemented full virulence. Deletion of either gene individually generated the same phenotype as the double knockout, indicating that both
pafR
and
pafP
are important to pathogenesis. We screened numerous environmental conditions but failed to detect expression from the promoter that precedes the
paf
genes
in vitro
, suggesting that they are
in vivo
induced (ivi). Although PafR is shown here to be capable of functioning as a transcriptional antiterminator, its targets in the UPEC genome are not known. Using microarray analysis, we have shown that expression of PafR from a heterologous promoter in CFT073 affects expression of genes related to bacterial virulence, biofilm formation, and metabolism. Expression of PafR also inhibits biofilm formation and motility. Taken together, our results suggest that the
paf
genes are implicated in pathogenesis and that PafR controls virulence genes, in particular biofilm formation genes.
Overlapping Functionality of the Pht Proteins in Zinc Homeostasis of Streptococcus pneumoniae
Authors: Plumptre Charles D. , Hughes Catherine E. , Harvey Richard M. , Eijkelkamp Bart A. , McDevitt Christopher A. , Paton James C.
Published: July 2014

Streptococcus pneumoniae
is a globally significant pathogen that causes a range of diseases, including pneumonia, sepsis, meningitis, and otitis media. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including transition metal ions such as zinc. The pneumococcus employs a number of surface proteins to achieve this, among which are four highly similar polyhistidine triad (Pht) proteins. It has previously been established that these proteins collectively aid in the delivery of zinc to the ABC transporter substrate-binding protein AdcAII. Here we have investigated the contribution of each individual Pht protein to pneumococcal zinc homeostasis by analyzing mutant strains expressing only one of the four
pht
genes. Under conditions of low zinc availability, each of these mutants showed superior growth and zinc accumulation profiles relative to a mutant strain lacking all four genes, indicating that any of the four Pht proteins are able to facilitate delivery of zinc to AdcAII. However, optimal growth and zinc accumulation
in vitro
and pneumococcal survival and proliferation
in vivo
required production of all four Pht proteins, indicating that, despite their overlapping functionality, the proteins are not dispensable without incurring a fitness cost. We also show that surface-attached forms of the Pht proteins are required for zinc recruitment and that they do not contribute to defense against extracellular zinc stress.