bluuebunny/crossref_metadata_2025 huggingface dataset:
Exudate collection using wound sponges—An easy, non‐invasive and reliable method to explore protease activities in ulcers
Authors: Ruf Marie‐Thérèse , Andreoli Arianna , Vujic Gabriel , Itin Peter , Pluschke Gerd , Schmid Peter
Published: April 2017

Proteases are important for wound healing, but in excessive amounts or left uncontrolled, they may cause healing impairment or other severe wound complications. Point‐of‐care testing for protease activities in wounds may be useful for monitoring the effectiveness of treatment, and for early identification of wounds that potentially fail to heal. Here we describe an easy, noninvasive method to collect wound fluid for evaluating the protease milieu of wounds. Wound fluids were collected using sterile sponges applied between wound surface and normal wound dressing. Wound fluid could be easily squeezed or centrifuged out of the sponges and was tested for gelatinase (MMP‐2 and MMP‐9) activities by gel zymography. In addition, we measured polymorphonuclear granulocyte elastase levels by ELISA. Both gelatinases were remarkably stable in sponge derived fluids, as no significant loss was observed even when samples were stored for 3 days at room temperature. Protease levels were highly diverse amongst patients and, in some cases, showed substantial variations in the course of the treatment. The here described wound sponge approach represents a patient‐friendly and reliable method to collect wound fluid for evaluating wound healing relevant biomarkers, such as matrix metalloproteinases.
Antibacterial activity of polihexanide formulations in a co‐culture of HaCaT keratinocytes and Staphylococcus aureus and at different pH levels
Authors: Wiegand Cornelia , Eberlein Thomas , Andriessen Anneke
Published: April 2017

Complex stalled wounds feature an alkaline milieu that favors tissue destruction and microbial growth. The presence of bacteria in turn perpetuates the inflammatory response. However, only limited knowledge exists of pH dependency on the antibacterial efficacy of polyhexamethylene biguanide (PHMB) or the influence of surfactants or delivery vehicle used in antiseptic formulations. So far, PHMB alone has been shown to protect the keratinocytes from bacterial damage in such a co‐culture system as well as exhibiting increased antimicrobial activity at higher pH values. Here, the interaction of PHMB with the surfactants macrogolum and undecylenamidopropyl betaine that are most commonly used as additives in antiseptics and rinsing solutions such as Lavasept and Prontosan has been explored in addition to the PHMB‐containing biocellulose dressing Suprasorb X + PHMB. Undecylenamidopropyl betaine was found to lower the antimicrobial activity of polihexanide in the co‐culture system, while macrogolum and the biocellulose increased polihexanide efficiency to reduce Staphylococcus aureus especially in the presence of serum. The increasing antibacterial efficacy of PHMB with rising pH was not altered by undecylenamidopropyl betaine, macrogolum, or the biocellulose. The results suggest that application of PHMB with macrogolum or by delivery through a biocellulose dressing might be advantageous for management of wound infections.
Quality of life in patients with primary and secondary lymphedema in the community
Authors: Herberger Katharina , Blome Christine , Heyer Kristina , Ellis Franziska , Münter Karl‐Christian , Augustin Matthias
Published: April 2017

Lymphedema is a complex and burdensome medical problem and requires continuous specific therapy. The aim of this cross‐sectional study of community lymphedema care in the metropolitan area of Hamburg, Germany, was to evaluate health‐related quality of life (QoL) in lymphedema patients. Generic as well as disease‐specific health‐related QoL was assessed using EQ‐5D and FLQA‐LK, respectively. Pain was assessed using a visual analogue scale (VAS). About 301 patients (median age of 60.5 years, 90.8% female) with lymphedema of any origin were included. About 66.4% had lymphedema, 24.1% combined lipolymphedema, and 9.5% lipoedema. Mean disease‐specific QoL (FLQA‐LK) was 2.4 (range 0 = no to 4 = maximum burden). The highest impairment values were observed in subscales for physical complaints, everyday life, and emotional well‐being. Mean EQ‐5D VAS was 70.4, mean EQ‐5D score 63.3. Lymphedema was associated with major impairments in QoL, which differed for subgroups of pain, clinical severity, and comorbidity. Pain as a common problem for lymphedema patients seemed to be underestimated and undertreated. Early diagnosis and structured treatment strategies are urgently needed.
Cost‐effectiveness analysis of single‐use negative pressure wound therapy dressings (sNPWT) to reduce surgical site complications (SSC) in routine primary hip and knee replacements
Authors: Nherera Leo M. , Trueman Paul , Karlakki Sudheer L.
Published: April 2017

We sought to evaluate the cost‐effectiveness of single‐use negative pressure wound therapy in patients undergoing primary hip and knee replacements using effectiveness data from a recently completed non‐blinded randomized controlled trial. A decision analytic model was developed from UK National Health Service perspective using data from a single‐centre trial. 220 patients were randomized to treatment with either single‐use negative pressure wound therapy or standard care i.e., film dressings of clinician choice and followed for 6 weeks. Outcomes included dressing changes, length of stay, surgical site complications, cost and quality adjusted life years. The randomized controlled trial reported a reduction in dressing changes (p = 0.002), SSC (p = 0.06) and LOS (p = 0.07) in favor of single‐use negative pressure wound therapy compared with standard care. The model estimated 0.116 and 0.115 QALY gained, 0.98 and 0.92 complications avoided for single‐use negative pressure wound therapy and standard care, respectively. The cost/patient was £5,602 ($7,954) and £6,713 ($9,559) for single‐use negative pressure wound therapy and standard care respectively resulting in cost‐saving of £1,132 ($1,607) in favor of single‐use negative pressure wound therapy. Greater savings were observed in subgroups of higher risk patients with BMI ≥ 35 and ASA ≥ 3 i.e., £7,955 ($11,296) and £7,248 ($10,293), respectively. The findings were robust to a range of sensitivity analyses. In conclusion, single‐use negative pressure wound therapy can be considered a cost saving intervention to reduce surgical site complications following primary hip and knee replacements compared with standard care. Providers should consider targeting therapy to those patients at elevated risk of surgical site complications to maximize efficiency.
Formative Assessment Using Multiple Choice Questions in Statics and Dynamics
Authors: Ghosh Amitabha
Published: April 2017

A two-loop learning outcomes assessment process was followed to evaluate the core curriculum in Mechanical Engineering at Rochester Institute of Technology. This initiative, originally called the Engineering Sciences Core Curriculum, provided systematic course learning outcomes and assessment data of examination performance in Statics, Mechanics, Dynamics, Thermodynamics, Fluid Mechanics and Heat Transfer. This paper reports longitudinal data and important observations in the Statics-Dynamics sequence to determine efficacy and obstacles in student performance. An earlier paper showed that students’ mastery of Dynamics is affected largely by weak retention of fundamentals of Statics and mathematics. New observations recorded in this report suggest the need for better instructional strategies to teach certain focal areas in Statics. Subsequesntly offered Dynamics and Fluid Mechanics classes further need reinforcement of some of these fundamental topics in Statics. This report completes a 9 year long broader feedback loop designed to achieve the educational goals in the Statics-Dynamics sequence.
Intra-speaker and inter-speaker variability in speech sound pressure level across repeated readings
Authors: Castellana Antonella , Carullo Alessio , Astolfi Arianna , Puglisi Giuseppina Emma , Fugiglando Umberto
Published: April 2017

The intra- and inter-speaker variability of speech sound pressure level (SPL) has been investigated under repeatability conditions in this work. In a semi-anechoic chamber, speech from 17 individuals was recorded with a sound level meter, a headworn microphone, and a vocal monitoring device. The subjects were asked to read twice and in sequence two phonetically balanced passages. The speech variability has been investigated for mean, equivalent, and mode SPL from each reading and device. The intra-speaker variability has been evaluated by means of the average among individual standard deviations in the four readings and it reached the maximum of 2 dB for mode SPL. For the inter-speaker variability, the experimental standard deviation of individual averaged SPL parameters among the four repeated measures has been calculated, obtaining the highest value of 5.3 dB for mode SPL. Changes in SPL variability have been evaluated with different logging intervals for each device. The influence of speech material has been investigated by the Wilcoxon test on paired lists of descriptive statistics for SPL distribution and equivalent SPL in the repeated readings. The data reported in this study may be considered as a preliminary reference for the investigation of changes in speech SPL over subjects.
Development of a Novel Site-Specific Pegylated Interferon Beta for Antiviral Therapy of Chronic Hepatitis B Virus
Authors: Tsuge Masataka , Uchida Takuro , Hiraga Nobuhiko , Kan Hiromi , Makokha Grace Naswa , Abe-Chayama Hiromi , Miki Daiki , Imamura Michio , Ochi Hidenori , Hayes C. Nelson , Shimozono Rieko , Iwamura Tomokatsu , Narumi Hideki , Suzuki Tomohiko , Kainoh Mie , Taniguchi Tadatsugu , Chayama Kazuaki
Published: April 2017

Although nucleot(s)ide analogues and pegylated interferon alpha 2a (PEG-IFN-α2a) can suppress hepatitis B virus (HBV) replication, it is difficult to achieve complete HBV elimination from hepatocytes. A novel site-specific pegylated recombinant human IFN-β (TRK-560) was recently developed. In the present study, we evaluated the antiviral effects of TRK-560 on HBV replication
in vitro
and
in vivo. In vitro
and
in vivo
HBV replication models were treated with antivirals including TRK-560, and changes in HBV markers were evaluated. To analyze antiviral mechanisms, cDNA microarray analysis and an enzyme-linked immunoassay (ELISA) were performed. TRK-560 significantly suppressed the production of intracellular HBV replication intermediates and extracellular HBV surface antigen (HBsAg) (
P
< 0.001 and
P
< 0.001, respectively), and the antiviral effects of TRK-560 were enhanced in combination with nucleot(s)ide analogues, such as entecavir and tenofovir disoproxil fumarate. The reduction in HBV DNA levels by TRK-560 treatment was significantly higher than that by PEG-IFN-α2a treatment both
in vitro
and
in vivo
(
P
= 0.004 and
P
= 0.046, respectively), and intracellular HBV covalently closed circular DNA (cccDNA) reduction by TRK-560 treatment was also significantly higher than that by PEG-IFN-α2a treatment
in vivo
(
P
= 0.0495). cDNA microarrays and ELISA for CXCL10 production revealed significant differences between TRK-560 and PEG-IFN-α2a in the induction potency of interferon-stimulated genes. TRK-560 shows a stronger antiviral potency via higher induction of interferon-stimulated genes and stronger stimulation of immune cell chemotaxis than PEG-IFN-α2a. As HBsAg loss and HBV cccDNA eradication are important clinical goals, these results suggest a potential role for TRK-560 in the development of more effective treatment for chronic hepatitis B infection.
High-Level Resistance of Staphylococcus aureus to β-Lactam Antibiotics Mediated by Penicillin-Binding Protein 4 (PBP4)
Authors: Hamilton Stephanie M. , Alexander J. Andrew N. , Choo Eun Ju , Basuino Li , da Costa Thaina M. , Severin Anatoly , Chung Marilyn , Aedo Sandra , Strynadka Natalie C. J. , Tomasz Alexander , Chatterjee Som S. , Chambers Henry F.
Published: April 2017

Penicillin-binding protein 4 (PBP4), a nonessential, low-molecular-weight penicillin-binding protein of
Staphylococcus aureus
, has been implicated in low-level resistance to β-lactam antibiotics, although the mechanism is unknown. Mutations in PBP4 and its promoter were identified in a laboratory-generated mutant strain, CRB, which expresses high-level resistance to β-lactams, including resistance to the new-generation cephalosporins active against methicillin-resistant strains of
S. aureus
. These mutations did not appreciably alter the β-lactam antibiotic binding affinity of purified recombinant mutant PBP4 compared to that of wild-type PBP4. Compared to the susceptible parent strain, COLnex, the CRB strain produces a highly cross-linked cell wall peptidoglycan, indicative of increased transpeptidase activity. The
pbp4
promoter mutation of CRB was associated with greatly increased amounts of PBP4 in membranes compared to those in the COLnex parent. Replacement of the native promoter of COLnex with the mutant promoter of CRB resulted in increased amounts of PBP4 in membranes and a highly cross-linked cell wall. PBP4 can be repurposed to provide essential transpeptidase activity
in vivo
and confer high-level resistance to β-lactam antibiotics, such as ceftobiprole and ceftaroline.
Improved Xylose Metabolism by a
CYC8
Mutant of Saccharomyces cerevisiae
Authors: Nijland Jeroen G. , Shin Hyun Yong , Boender Leonie G. M. , de Waal Paul P. , Klaassen Paul , Driessen Arnold J. M.
Published: April 2017

Engineering
Saccharomyces cerevisiae
for the utilization of pentose sugars is an important goal for the production of second-generation bioethanol and biochemicals. However,
S. cerevisiae
lacks specific pentose transporters, and in the presence of glucose, pentoses enter the cell inefficiently via endogenous hexose transporters (HXTs). By means of
in vivo
engineering, we have developed a quadruple hexokinase deletion mutant of
S. cerevisiae
that evolved into a strain that efficiently utilizes
d
-xylose in the presence of high
d
-glucose concentrations. A genome sequence analysis revealed a mutation (Y353C) in the general corepressor
CYC8
, or
SSN6
, which was found to be responsible for the phenotype when introduced individually in the nonevolved strain. A transcriptome analysis revealed altered expression of 95 genes in total, including genes involved in (i) hexose transport, (ii) maltose metabolism, (iii) cell wall function (mannoprotein family), and (iv) unknown functions (seripauperin multigene family). Of the 18 known HXTs, genes for 9 were upregulated, especially the low or nonexpressed
HXT10
,
HXT13
,
HXT15
, and
HXT16
. Mutant cells showed increased uptake rates of
d
-xylose in the presence of
d
-glucose, as well as elevated maximum rates of metabolism (
V
max
) for both
d
-glucose and
d
-xylose transport. The data suggest that the increased expression of multiple hexose transporters renders
d
-xylose metabolism less sensitive to
d
-glucose inhibition due to an elevated transport rate of
d
-xylose into the cell.

IMPORTANCE
The yeast
Saccharomyces cerevisiae
is used for second-generation bioethanol formation. However, growth on xylose is limited by pentose transport through the endogenous hexose transporters (HXTs), as uptake is outcompeted by the preferred substrate, glucose. Mutant strains were obtained with improved growth characteristics on xylose in the presence of glucose, and the mutations mapped to the regulator Cyc8. The inactivation of Cyc8 caused increased expression of HXTs, thereby providing more capacity for the transport of xylose, presenting a further step toward a more robust process of industrial fermentation of lignocellulosic biomass using yeast.
The Tale of a Neglected Energy Source: Elevated Hydrogen Exposure Affects both Microbial Diversity and Function in Soil
Authors: Khdhiri Mondher , Piché-Choquette Sarah , Tremblay Julien , Tringe Susannah G. , Constant Philippe
Published: April 2017

The enrichment of H
2
-oxidizing bacteria (HOB) by H
2
generated by nitrogen-fixing nodules has been shown to have a fertilization effect on several different crops. The benefit of HOB is attributed to their production of plant growth-promoting factors, yet their interactions with other members of soil microbial communities have received little attention. Here we report that the energy potential of H
2
, when supplied to soil, alters ecological niche partitioning of bacteria and fungi, with multifaceted consequences for both generalist and specialist microbial functions. We used dynamic microcosms to expose soil to the typical atmospheric H
2
mixing ratio (0.5 ppmv) permeating soils, as well as mixing ratios comparable to those found at the soil-nodule interface (10,000 ppmv). Elevated H
2
exposure exerted direct effects on two HOB subpopulations distinguished by their affinity for H
2
while enhancing community level carbon substrate utilization potential and lowering CH
4
uptake activity in soil. We found that H
2
triggered changes in the abundance of microorganisms that were reproducible yet inconsistent across soils at the taxonomic level and even among HOB. Overall, H
2
exposure altered microbial process rates at an intensity that depends upon soil abiotic and biotic features. We argue that further examination of direct and indirect effects of H
2
on soil microbial communities will lead to a better understanding of the H
2
fertilization effect and soil biogeochemical processes.

IMPORTANCE
An innovative dynamic microcosm chamber system was used to demonstrate that H
2
diffusing in soil triggers changes in the distribution of HOB and non-HOB. Although the response was uneven at the taxonomic level, an unexpected coordinated response of microbial functions was observed, including abatement of CH
4
oxidation activity and stimulation of carbon turnover. Our work suggests that elevated H
2
rewires soil biogeochemical structure through a combination of direct effects on the growth and persistence of HOB and indirect effects on a variety of microbial processes involving HOB and non-HOB.
Reexamination of the Physiological Role of PykA in Escherichia coli Revealed that It Negatively Regulates the Intracellular ATP Levels under Anaerobic Conditions
Authors: Zhao Chunhua , Lin Zhao , Dong Hongjun , Zhang Yanping , Li Yin
Published: April 2017

Pyruvate kinase is one of the three rate-limiting glycolytic enzymes that catalyze the last step of glycolysis, conversion of phosphoenolpyruvate (PEP) into pyruvate, which is associated with ATP generation. Two isozymes of pyruvate kinase, PykF and PykA, are identified in
Escherichia coli
. PykF is considered important, whereas PykA has a less-defined role. Prior studies inactivated the
pykA
gene to increase the level of its substrate, PEP, and thereby increased the yield of end products derived from PEP. We were surprised when we found a
pykA
::Tn
5
mutant in a screen for increased yield of an end product derived from pyruvate (
n
-butanol), suggesting that the role of PykA needs to be reexamined. We show that the
pykA
mutant exhibited elevated intracellular ATP levels, biomass concentrations, glucose consumption, and
n
-butanol production. We also discovered that the
pykA
mutant expresses higher levels of a presumed pyruvate transporter, YhjX, permitting the mutant to recapture and metabolize excreted pyruvate. Furthermore, we demonstrated that the nucleotide diphosphate kinase activity of PykA leads to negative regulation of the intracellular ATP levels. Taking the data together, we propose that inactivation of
pykA
can be considered a general strategy to enhance the production of pyruvate-derived metabolites under anaerobic conditions.

IMPORTANCE
This study showed that knocking out
pykA
significantly increased the intracellular ATP level and thus significantly increased the levels of glucose consumption, biomass formation, and pyruvate-derived product formation under anaerobic conditions.
pykA
was considered to be encoding a dispensable pyruvate kinase; here we show that
pykA
negatively regulates the anaerobic glycolysis rate through regulating the energy distribution. Thus, knocking out
pykA
can be used as a general strategy to increase the level of pyruvate-derived fermentative products.
Toxicity and Binding Studies of Bacillus thuringiensis Cry1Ac, Cry1F, Cry1C, and Cry2A Proteins in the Soybean Pests Anticarsia gemmatalis and Chrysodeixis (Pseudoplusia) includens
Authors: Bel Yolanda , Sheets Joel J. , Tan Sek Yee , Narva Kenneth E. , Escriche Baltasar
Published: April 2017

Anticarsia gemmatalis
(velvetbean caterpillar) and
Chrysodeixis includens
(soybean looper, formerly named
Pseudoplusia includens
) are two important defoliating insects of soybeans. Both lepidopteran pests are controlled mainly with synthetic insecticides. Alternative control strategies, such as biopesticides based on the
Bacillus thuringiensis
(Bt) toxins or transgenic plants expressing Bt toxins, can be used and are increasingly being adopted. Studies on the insect susceptibilities and modes of action of the different Bt toxins are crucial to determine management strategies to control the pests and to delay outbreaks of insect resistance. In the present study, the susceptibilities of both soybean pests to the Bt toxins Cry1Ac, Cry1Fa, Cry1Ca, and Cry2Aa have been investigated. Bioassays performed in first-instar larvae showed that both insects are susceptible to all these toxins. Competition-binding studies carried out with Cry1Ac and Cry1Fa
125
-iodine labeled proteins demonstrated the presence of specific binding sites for both of them on the midgut brush border membrane vesicles (BBMVs) of both
A. gemmatalis
and
C. includens
. Competition-binding experiments and specific-binding inhibition studies performed with selected sugars and lectins indicated that Cry1Ac and Cry1Fa share some, but not all, binding sites in the midguts of both insects. Also, the Cry1Ac- or Cry1Fa-binding sites were not shared with Cry1Ca or Cry2Aa in either soybean pest. This study contributes to the knowledge of Bt toxicity and midgut toxin binding sites in
A. gemmatalis
and
C. includens
and sheds light on the cross-resistance potential of Cry1Ac, Cry1Fa, Cry1Ca, and Cry2Aa Bt proteins as candidate proteins for Bt-pyramided crops.

IMPORTANCE
In the present study, the toxicity and the mode of action of the
Bacillus thuringiensis
(Bt) toxins Cry1Ac, Cry1Fa, Cry1Ca, and Cry2Aa in
Anticarsia gemmatalis
and
Chrysodeixis includens
(important defoliating pests of soybeans) have been investigated. These studies are crucial for determining management strategies for pest control. Bioassays showed that both insects were susceptible to the toxins. Competition-binding studies demonstrated the presence of Cry1Fa- and Cry1Ac-specific binding sites in the midguts of both pests. These results, together with the results from binding inhibition studies performed with sugars and lectins, indicated that Cry1Ac and Cry1Fa share some, but not all, binding sites, and that they were not shared with Cry1Ca or Cry2Aa in either soybean pest. This study contributes to the knowledge of Bt toxicity in
A. gemmatalis
and
C. includens
and sheds light on the cross-resistance potential of Cry1Ac, Cry1Fa, Cry1Ca, and Cry2Aa Bt proteins as candidate proteins for Bt-pyramided crops.
Simulated rRNA/DNA Ratios Show Potential To Misclassify Active Populations as Dormant
Authors: Steven Blaire , Hesse Cedar , Soghigian John , Gallegos-Graves La Verne , Dunbar John
Published: April 2017

The use of rRNA/DNA ratios derived from surveys of rRNA sequences in RNA and DNA extracts is an appealing but poorly validated approach to infer the activity status of environmental microbes. To improve the interpretation of rRNA/DNA ratios, we performed simulations to investigate the effects of community structure, rRNA amplification, and sampling depth on the accuracy of rRNA/DNA ratios in classifying bacterial populations as “active” or “dormant.” Community structure was an insignificant factor. In contrast, the extent of rRNA amplification that occurs as cells transition from dormant to growing had a significant effect (
P
< 0.0001) on classification accuracy, with misclassification errors ranging from 16 to 28%, depending on the rRNA amplification model. The error rate increased to 47% when communities included a mixture of rRNA amplification models, but most of the inflated error was false negatives (i.e., active populations misclassified as dormant). Sampling depth also affected error rates (
P
< 0.001). Inadequate sampling depth produced various artifacts that are characteristic of rRNA/DNA ratios generated from real communities. These data show important constraints on the use of rRNA/DNA ratios to infer activity status. Whereas classification of populations as active based on rRNA/DNA ratios appears generally valid, classification of populations as dormant is potentially far less accurate.

IMPORTANCE
The rRNA/DNA ratio approach is appealing because it extracts an extra layer of information from high-throughput DNA sequencing data, offering a means to determine not only the seedbank of taxa present in communities but also the subset of taxa that are metabolically active. This study provides crucial insights into the use of rRNA/DNA ratios to infer the activity status of microbial taxa in complex communities. Our study shows that the approach may not be as robust as previously supposed, particularly in complex communities composed of populations employing different growth strategies, and identifies factors that inflate the erroneous classification of active populations as dormant.
Contamination of Fresh Produce by Microbial Indicators on Farms and in Packing Facilities: Elucidation of Environmental Routes
Authors: Bartz Faith E. , Lickness Jacquelyn Sunshine , Heredia Norma , Fabiszewski de Aceituno Anna , Newman Kira L. , Hodge Domonique Watson , Jaykus Lee-Ann , García Santos , Leon Juan S.
Published: April 2017

To improve food safety on farms, it is critical to quantify the impact of environmental microbial contamination sources on fresh produce. However, studies are hampered by difficulties achieving study designs with powered sample sizes to elucidate relationships between environmental and produce contamination. Our goal was to quantify, in the agricultural production environment, the relationship between microbial contamination on hands, soil, and water and contamination on fresh produce. In 11 farms and packing facilities in northern Mexico, we applied a matched study design: composite samples (
n
= 636, equivalent to 11,046 units) of produce rinses were matched to water, soil, and worker hand rinses during two growing seasons. Microbial indicators (coliforms,
Escherichia coli
,
Enterococcus
spp., and somatic coliphage) were quantified from composite samples. Statistical measures of association and correlations were calculated through Spearman's correlation, linear regression, and logistic regression models. The concentrations of all microbial indicators were positively correlated between produce and hands (ρ range, 0.41 to 0.75;
P
< 0.01). When
E. coli
was present on hands, the handled produce was nine times more likely to contain
E. coli
(
P
< 0.05). Similarly, when coliphage was present on hands, the handled produce was eight times more likely to contain coliphage (
P
< 0.05). There were relatively low concentrations of indicators in soil and water samples, and a few sporadic significant associations were observed between contamination of soil and water and contamination of produce. This methodology provides a foundation for future field studies, and results highlight the need for interventions surrounding farmworker hygiene and sanitation to reduce microbial contamination of farmworkers' hands.

IMPORTANCE
This study of the relationships between microbes on produce and in the farm environment can be used to support the design of targeted interventions to prevent or reduce microbial contamination of fresh produce with associated reductions in foodborne illness.
The PerR-Regulated P
1B-4
-Type ATPase (PmtA) Acts as a Ferrous Iron Efflux Pump in Streptococcus pyogenes
Authors: Turner Andrew G. , Ong Cheryl-lynn Y. , Djoko Karrera Y. , West Nicholas P. , Davies Mark R. , McEwan Alastair G. , Walker Mark J.
Published: April 2017

Streptococcus pyogenes
(group A
Streptococcus
[GAS]) is an obligate human pathogen responsible for a broad spectrum of human disease. GAS has a requirement for metal homeostasis within the human host and, as such, tightly modulates metal uptake and efflux during infection. Metal acquisition systems are required to combat metal sequestration by the host, while metal efflux systems are essential to protect against metal overload poisoning. Here, we investigated the function of PmtA (
P
erR-regulated
m
etal
t
ransporter
A
), a P
1B-4
-type ATPase efflux pump, in invasive GAS M1T1 strain 5448. We reveal that PmtA functions as a ferrous iron [Fe(II)] efflux system. In the presence of high Fe(II) concentrations, the 5448Δ
pmtA
deletion mutant exhibited diminished growth and accumulated 5-fold-higher levels of intracellular Fe(II) than did the wild type and the complemented mutant. The 5448Δ
pmtA
deletion mutant also showed enhanced susceptibility to killing by the Fe-dependent antibiotic streptonigrin as well as increased sensitivity to hydrogen peroxide and superoxide. We suggest that the PerR-mediated control of Fe(II) efflux by PmtA is important for bacterial defense against oxidative stress. PmtA represents an exemplar for an Fe(II) efflux system in a host-adapted Gram-positive bacterial pathogen.
The Agr-Like Quorum Sensing System Is Required for Pathogenesis of Necrotic Enteritis Caused by Clostridium perfringens in Poultry
Authors: Yu Qiang , Lepp Dion , Mehdizadeh Gohari Iman , Wu Tao , Zhou Hongzhuan , Yin Xianhua , Yu Hai , Prescott John F. , Nie Shao-Ping , Xie Ming-Yong , Gong Joshua
Published: April 2017

Clostridium perfringensencodes at least two different quorum sensing (QS) systems, the Agr-like and LuxS, and recent studies have highlighted their importance in the regulation of toxin production and virulence. The role of QS in the pathogenesis of necrotic enteritis (NE) in poultry and the regulation of NetB, the key toxin involved, has not yet been investigated. We have generated isogenicagrB-null and complemented strains from parent strain CP1 and demonstrated that the virulence of theagrB-null mutant was strongly attenuated in a chicken NE model system and restored by complementation. The production of NetB, a key NE-associated toxin, was dramatically reduced in theagrBmutant at both the transcriptional and protein levels, though not in aluxSmutant. Transwell assays confirmed that the Agr-like QS system controls NetB production through a diffusible signal. Global gene expression analysis of theagrBmutant identified additional genes modulated by Agr-like QS, including operons related to phospholipid metabolism and adherence, which may also play a role in NE pathogenesis. This study provides the first evidence that the Agr-like QS system is critical for NE pathogenesis and identifies a number of Agr-regulated genes, most notablynetB, that are potentially involved in mediating its effects. The Agr-like QS system thus may serve as a target for developing novel interventions to prevent NE in chickens.
The Variable Internal Structure of the Mycoplasma penetrans Attachment Organelle Revealed by Biochemical and Microscopic Analyses: Implications for Attachment Organelle Mechanism and Evolution
Authors: Distelhorst Steven L. , Jurkovic Dominika A. , Shi Jian , Jensen Grant J. , Balish Mitchell F.
Published: April 2017

Although mycoplasmas have small genomes, many of them, including the HIV-associated opportunist
Mycoplasma penetrans
, construct a polar attachment organelle (AO) that is used for both adherence to host cells and gliding motility. However, the irregular phylogenetic distribution of similar structures within the mycoplasmas, as well as compositional and ultrastructural differences among these AOs, suggests that AOs have arisen several times through convergent evolution. We investigated the ultrastructure and protein composition of the cytoskeleton-like material of the
M. penetrans
AO with several forms of microscopy and biochemical analysis, to determine whether the
M. penetrans
AO was constructed at the molecular level on principles similar to those of other mycoplasmas, such as
Mycoplasma pneumoniae
and
Mycoplasma mobile
. We found that the
M. penetrans
AO interior was generally dissimilar from that of other mycoplasmas, in that it exhibited considerable heterogeneity in size and shape, suggesting a gel-like nature. In contrast, several of the 12 potential protein components identified by mass spectrometry of
M. penetrans
detergent-insoluble proteins shared certain distinctive biochemical characteristics with
M. pneumoniae
AO proteins, although not with
M. mobile
proteins. We conclude that convergence between
M. penetrans
and
M. pneumoniae
AOs extends to the molecular level, leading to the possibility that the less organized material in both
M. pneumoniae
and
M. penetrans
is the substance principally responsible for the organization and function of the AO.

IMPORTANCE
Mycoplasma penetrans
is a bacterium that infects HIV-positive patients and may contribute to the progression of AIDS. It attaches to host cells through a structure called an AO, but it is not clear how it builds this structure. Our research is significant not only because it identifies the novel protein components that make up the material within the AO that give it its structure but also because we find that the
M. penetrans
AO is organized unlike AOs from other mycoplasmas, suggesting that similar structures have evolved multiple times. From this work, we derive some basic principles by which mycoplasmas, and potentially all organisms, build structures at the subcellular level.
Electrical and structural adaptations of the paediatric athlete’s heart: a systematic review with meta-analysis
Authors: McClean Gavin , Riding Nathan R , Ardern Clare L , Farooq Abdulaziz , Pieles Guido E , Watt Victoria , Adamuz Carmen , George Keith P , Oxborough David , Wilson Mathew G
Published: April 2017

Aim

To describe the electrocardiographic (ECG) and echocardiographic manifestations of the paediatric athlete’s heart, and examine the impact of age, race and sex on cardiac remodelling responses to competitive sport.

Design

Systematic review with meta-analysis.

Data sources

Six electronic databases were searched to May 2016: MEDLINE, PubMed, EMBASE, Web of Science, CINAHL and SPORTDiscus.

Inclusion criteria

(1) Male and/or female competitive athletes, (2) participants aged 6–18 years, (3) original research article published in English language.

Results

Data from 14 278 athletes and 1668 non-athletes were included for qualitative (43 articles) and quantitative synthesis (40 articles). Paediatric athletes demonstrated a greater prevalence of training-related and training-unrelated ECG changes than non-athletes. Athletes ≥14 years were 15.8 times more likely to have inferolateral T-wave inversion than athletes <14 years. Paediatric black athletes had significantly more training-related and training-unrelated ECG changes than Caucasian athletes. Age was a positive predictor of left ventricular (LV) internal diameter during diastole, interventricular septum thickness during diastole, relative wall thickness and LV mass. When age was accounted for, these parameters remained significantly larger in athletes than non-athletes. Paediatric black athletes presented larger posterior wall thickness during diastole (PWTd) than Caucasian athletes. Paediatric male athletes also presented larger PWTd than females.

Conclusions

The paediatric athlete’s heart undergoes significant remodelling both before and during ‘maturational years’. Paediatric athletes have a greater prevalence of training related and training-unrelated ECG changes than non-athletes, with age, race and sex mediating factors on cardiac electrical and LV structural remodelling.
Analysis of CTG repeat length variation in theDMPKgene in the general population and the molecular diagnosis of myotonic dystrophy type 1 in Malaysia
Authors: Ambrose Kathlin K , Ishak Taufik , Lian Lay-Hoong , Goh Khean-Jin , Wong Kum-Thong , Ahmad-Annuar Azlina , Thong Meow-Keong
Published: April 2017

Objective

The lack of epidemiological data and molecular diagnostic services in Malaysia has hampered the setting-up of a comprehensive management plan for patients with myotonic dystrophy type 1 (DM1), leading to delayed diagnosis, treatment and support for patients and families. The aim of this study was to estimate the prevalence of DM1 in the 3 major ethnic groups in Malaysia and evaluate the feasibility of a single tube triplet-primed PCR (TP-PCR) method for diagnosis of DM1 in Malaysia.

Design, setting and participants

We used PCR to determine the size of CTG repeats in 377 individuals not known to be affected by DM and 11 DM1 suspected patients, recruited from a tertiary hospital in Kuala Lumpur. TP-PCR was performed on selected samples, followed by Southern blot hybridisation of PCR amplified fragments to confirm and estimate the size of CTG expansion.

Outcome measures

The number of individuals not known to be affected by DM with (CTG)>18was determined according to ethnic group and as a whole population. The χ2test was performed to compare the distribution of (CTG)>18with 12 other populations. Additionally, the accuracy of TP-PCR in detecting CTG expansion in 11 patients with DM1 was determined by comparing the results with that from Southern blot hybridisation.

Results

Of the 754 chromosomes studied, (CTG)>18frequency of 3.60%, 1.57% and 4.00% in the Malay, Chinese and Indian subpopulations, respectively, was detected, showing similarities to data from Thai, Taiwanese and Kuwaiti populations. We also successfully detected CTG expansions in 9 patients using the TP-PCR method followed by the estimation of CTG expansion size via Southern blot hybridisation.

Conclusions

The results show a low DM1 prevalence in Malaysia with the possibility of underdiagnosis and demonstrates the feasibility of using a clinical and TP-PCR-based approach for rapid and cost-effective DM1 diagnosis in developing countries.
Impact of changes in pill appearance in the adherence to angiotensin receptor blockers and in the blood pressure levels: a retrospective cohort study
Authors: Lumbreras B , López-Pintor E
Published: April 2017

Objective

To assess the level of adherence to angiotensin receptor blockers (ARBs) in patients regularly attending a community pharmacy and the influence of a change in patients' adherence to pharmacological treatment.

Design

Retrospective cohort study of a random sample of consecutive patients collecting their medication.

Setting

40 community pharmacies in Alicante (Southeast Spain).

Participants

602 consecutive ≥18 years old patients following treatment with ARBs at least 3 previous refills were included.

Main outcome measures

Prevalence of uncontrolled blood pressure (BP) and adherence to prescribed pharmacological treatment (measured through both the Batalla and the Morisky-Green tests). A multivariate Poisson regression model was used to estimate the adjusted risk ratio (RRa) for non-adherence to pharmacological treatment by the presence of a change in patient's adherence and other significant variables.

Results

161/602 (13.7%) patients presented uncontrolled BP. According to the Morisky test, 410/602 (68.2%) patients were considered adherent to pharmacological treatment and 231/602 (38.4%) patients according to the Batalla test. According to the Morisky-Green test, in the multivariable analysis, patients with a previous change in pill appearance were less likely to be adherent than those patients with no change in their pharmacological treatment (RRa 0.45; CI 95% 0.22 to 0.90; p=0.024). Systolic BP was higher in patients with a change in pill appearance in the previous 3 refills (median BP 142 mm Hg; IQR 136–148) than in those who did not have a change (median BP 127 mm Hg; IQR 118–135; p<0.001).

Conclusions

There was a low percentage of adherence and nearly 15% of uncontrolled BP in patients who regularly collected their medication. Switching between pills of different appearances was associated with lower patient adherence to pharmacological treatment and a higher uncontrolled BP than no change in pharmacological treatment or change only in package but not in pill appearance.
Evidence of potential bias in a comparison of β blockers and calcium channel blockers in patients with chronic obstructive pulmonary disease and acute coronary syndrome: results of a multinational study
Authors: Dong Yaa-Hui , Alcusky Matthew , Maio Vittorio , Liu Jun , Liu Mengdan , Wu Li-Chiu , Chang Chia-Hsuin , Lai Mei-Shu , Gagne Joshua J
Published: April 2017

Objectives

A number of observational studies have reported that, in patients with chronic obstructive pulmonary disease (COPD), β blockers (BBs) decrease risk of mortality and COPD exacerbations. To address important methodological concerns of these studies, we compared the effectiveness and safety of cardioselective BBs versus non-dihydropyridine calcium channel blockers (non-DHP CCBs) in patients with COPD and acute coronary syndromes (ACS) using a propensity score (PS)-matched, active comparator, new user design. We also assessed for potential unmeasured confounding by examining a short-term COPD hospitalisation outcome.

Setting and participants

We identified 22 985 patients with COPD and ACS starting cardioselective BBs or non-DHP CCBs across 5 claims databases from the USA, Italy and Taiwan.

Primary and secondary outcome measures

Stratified Cox regression models were used to estimate HRs for mortality, cardiovascular (CV) hospitalisations and COPD hospitalisations in each database after variable-ratio PS matching. Results were combined with random-effects meta-analyses.

Results

Cardioselective BBs were not associated with reduced risk of mortality (HR, 0.90; 95% CI 0.78 to 1.02) or CV hospitalisations (HR, 1.06; 95% CI 0.91 to 1.23), although statistical heterogeneity was observed across databases. In contrast, a consistent, inverse association for COPD hospitalisations was identified across databases (HR, 0.54; 95% CI 0.47 to 0.61), which persisted even within the first 30 days of follow-up (HR, 0.55; 95% CI 0.37 to 0.82). Results were similar across a variety of sensitivity analyses, including PS trimming, high dimensional-PS matching and restricting to high-risk patients.

Conclusions

This multinational study found a large inverse association between cardioselective BBs and short-term COPD hospitalisations. The persistence of this bias despite state-of-the-art pharmacoepidemiologic methods calls into question the ability of claims data to address confounding in studies of BBs in patients with COPD.
Awareness and attitudes of the Lebanese population with regard to physician–pharmaceutical company interaction: a survey study
Authors: Ammous Ahmad , Bou Zein Eddine Savo , Dani Alia , Dbaibou Jana , El-Asmar Jose M , Sadder Liane , Akl Elie A
Published: April 2017

Objective

To assess the awareness and attitudes of the general public in Lebanon regarding the interactions between physicians and pharmaceutical companies.

Setting

Primary healthcare clinics and shopping malls in the Greater Beirut Area.

Participants

263 participants completed the questionnaire, of whom 62% were female and 38% were male. Eligible participants were Arabic-speaking or English-speaking adults (age≥18 years) residing in Lebanon for at least 5 years.

Primary and secondary outcome measures

Awareness, attitudes and beliefs of the general public.

Results

263 out of 295 invited individuals (89% completion rate) completed the questionnaire. While the majority of participants were aware of pharmaceutical company presence (or absence) in physicians' offices (range of 71–76% across questions), smaller percentages were aware of gift-related practices of physicians (range of 26–69% across questions). 40% thought that the acceptance of small gifts or meals by physicians is wrong/unethical. The percentage of participants reporting lower trust in physicians due to their participation in various pharmaceutical company-related activities ranged from 12% to 45% (the highest percentage being for large gifts). Participants who reported receiving free medication samples were significantly more likely to consider physicians' acceptance of small gifts as ‘not a problem’ than ‘unethical’ (OR=1.53; p=0.044).

Conclusions

Participants in our survey were generally more aware of pharmaceutical company presence (or absence) in physicians' offices than of gift-related practices of physicians. While the level of trust was not affected for the majority of participants for various types of interactions, it was affected the most for accepting large gifts.
Interactive web-based pulmonary rehabilitation programme: a randomised controlled feasibility trial
Authors: Chaplin Emma , Hewitt Stacey , Apps Lindsay , Bankart John , Pulikottil-Jacob Ruth , Boyce Sally , Morgan Mike , Williams Johanna , Singh Sally
Published: April 2017

Objectives

The aim of this study was to determine if an interactive web-based pulmonary rehabilitation (PR) programme is a feasible alternative to conventional PR.

Design

Randomised controlled feasibility trial.

Setting

Participants with a diagnosis of chronic obstructive pulmonary disease were recruited from PR assessments, primary care and community rehabilitation programmes. Patients randomised to conventional rehabilitation started the programme according to the standard care at their referred site on the next available date.

Participants

103 patients were recruited to the study and randomised: 52 to conventional rehabilitation (mean (±SD) age 66 (±8) years, Medical Research Council (MRC) 3 (IQR2–4)); 51 to the web arm (mean (±SD) age 66 (±10) years, MRC 3 (IQR2–4)). Participants had to be willing to participate in either arm of the trial, have internet access and be web literate.

Interventions

Patients randomised to the web-based programme worked through the website, exercising and recording their progress as well as reading educational material. Conventional PR consisted of twice weekly, 2 hourly sessions (an hour for exercise training and an hour for education).

Outcome measures

Recruitment rates, eligibility, patient preference and dropout and completion rates for both programmes were collected. Standard outcomes for a PR assessment including measures of exercise capacity and quality of life questionnaires were also evaluated.

Results

A statistically significant improvement (p≤0.01) was observed within each group in the endurance shuttle walk test (WEB: mean change 189±211.1; PR classes: mean change 184.5±247.4 s) and Chronic Respiratory disease Questionnaire-Dyspnoea (CRQ-D; WEB: mean change 0.7±1.2; PR classes: mean change 0.8±1.0). However, there were no significant differences between the groups in any outcome. Dropout rates were higher in the web-based programme (57% vs 23%).

Conclusions

An interactive web-based PR programme is feasible and acceptable when compared with conventional PR. Future trials maybe around choice-based PR programmes for select patients enabling stratification of patient care.

Trial registration number

ISRCTN03142263; Results.