bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Genome-Editing Platform for Drug-Resistant Acinetobacter baumannii Reveals an AdeR-Unrelated Tigecycline Resistance Mechanism
Authors: Trebosc Vincent , Gartenmann Sarah , Royet Kevin , Manfredi Pablo , Tötzl Marcus , Schellhorn Birgit , Pieren Michel , Tigges Marcel , Lociuro Sergio , Sennhenn Peter C. , Gitzinger Marc , Bumann Dirk , Kemmer Christian
Published: September 2016

Infections with the Gram-negative coccobacillus
Acinetobacter baumannii
are a major threat in hospital settings. The progressing emergence of multidrug-resistant clinical strains significantly reduces the treatment options for clinicians to fight
A. baumannii
infections. The current lack of robust methods to genetically manipulate drug-resistant
A. baumannii
isolates impedes research on resistance and virulence mechanisms in clinically relevant strains. In this study, we developed a highly efficient and versatile genome-editing platform enabling the markerless modification of the genome of
A. baumannii
clinical and laboratory strains, regardless of their resistance profiles. We applied this method for the deletion of AdeR, a transcription factor that regulates the expression of the AdeABC efflux pump in tigecycline-resistant
A. baumannii
, to evaluate its function as a putative drug target. Loss of
adeR
reduced the MIC
90
of tigecycline from 25 μg/ml in the parental strains to 3.1 μg/ml in the Δ
adeR
mutants, indicating its importance in the drug resistance phenotype. However, 60% of the clinical isolates remained nonsusceptible to tigecycline after
adeR
deletion. Evolution of artificial tigecycline resistance in two strains followed by whole-genome sequencing revealed loss-of-function mutations in
trm
, suggesting its role in an alternative AdeABC-independent tigecycline resistance mechanism. This finding was strengthened by the confirmation of
trm
disruption in the majority of the tigecycline-resistant clinical isolates. This study highlights the development and application of a powerful genome-editing platform for
A. baumannii
enabling future research on drug resistance and virulence pathways in clinically relevant strains.
Mycobacterium tuberculosis Arylamine
N
-Acetyltransferase Acetylates and Thus Inactivates
para
-Aminosalicylic Acid
Authors: Wang Xude , Yang Shanshan , Gu Jing , Deng Jiaoyu
Published: September 2016

Mycobacterium tuberculosis
arylamine
N
-acetyltransferase (TBNAT) is able to acetylate
para
-aminosalicylic acid (PAS) both
in vitro
and
in vivo
as determined by high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS) techniques. The antituberculosis activity of the acetylated PAS is significantly reduced. As a result, overexpression of TBNAT in
M. tuberculosis
results in PAS resistance, as determined by MIC tests and drug exposure experiments. Taken together, our results suggest that TBNAT from
M. tuberculosis
is able to inactivate PAS by acetylating the compound.
Population Pharmacokinetics and Pharmacodynamics Modeling To Optimize Dosage Regimens of Sulbactam in Critically Ill Patients with Severe Sepsis Caused by Acinetobacter baumannii
Authors: Jaruratanasirikul Sutep , Wongpoowarak Wibul , Wattanavijitkul Thitima , Sukarnjanaset Waroonrat , Samaeng Maseetoh , Nawakitrangsan Monchana , Ingviya Natnicha
Published: September 2016

Sulbactam is being considered as an alternative concomitant medication with other effective antibiotics for the treatment of multidrug-resistant (MDR)
Acinetobacter baumannii
infections. Pathophysiological changes in critically ill patients with severe sepsis, resulting in altered pharmacokinetic (PK) patterns for antibiotics, are important factors in determining therapeutic success. The aims of this study were (i) to examine the population PK parameters and (ii) to assess the probability of target attainment (PTA) for sulbactam in patients with severe sepsis caused by
A. baumannii
. PK studies were carried out following administration of 2 g of sulbactam every 12 h on the 4th day of drug administration in 27 patients, and a Monte Carlo simulation was performed to determine the PTA of achieving 40% exposure time during which the plasma drug concentration remained above the MIC (
T
>MIC
) and 60%
T
>MIC
. The central and peripheral volumes of distribution were 14.56 and 9.55 liters, respectively, and total clearances of sulbactam were 2.26 liters/h and 7.64 liters/h in patients aged >65 years and ≤65 years, respectively. The high PTAs (≥90%) for targets of 40%
T
>
MIC
and 60%
T
>
MIC
with a MIC of 4 μg/ml were observed when sulbactam was administered by a 4-h infusion of 1 g every 12 h and 1 g every 8 h, respectively. Sulbactam would be an alternative antibiotic option to coadminister with colistin for the treatment of infections caused by MDR
A. baumannii
. However, for pathogens with MICs of >4 μg/ml, higher dosage regimens of sulbactam are required.
The Bacterial Second Messenger Cyclic di-GMP Regulates Brucella Pathogenesis and Leads to Altered Host Immune Response
Authors: Khan Mike , Harms Jerome S. , Marim Fernanda M. , Armon Leah , Hall Cherisse L. , Liu Yi-Ping , Banai Menachem , Oliveira Sergio C. , Splitter Gary A. , Smith Judith A.
Published: September 2016

Brucella
species are facultative intracellular bacteria that cause brucellosis, a chronic debilitating disease significantly impacting global health and prosperity. Much remains to be learned about how
Brucella
spp. succeed in sabotaging immune host cells and how
Brucella
spp. respond to environmental challenges. Multiple types of bacteria employ the prokaryotic second messenger cyclic di-GMP (c-di-GMP) to coordinate responses to shifting environments. To determine the role of c-di-GMP in
Brucella
physiology and in shaping host-
Brucella
interactions, we utilized c-di-GMP regulatory enzyme deletion mutants. Our results show that a Δ
bpdA
phosphodiesterase mutant producing excess c-di-GMP displays marked attenuation
in vitro
and
in vivo
during later infections. Although c-di-GMP is known to stimulate the innate sensor STING, surprisingly, the Δ
bpdA
mutant induced a weaker host immune response than did wild-type
Brucella
or the low-c-di-GMP guanylate cyclase Δ
cgsB
mutant. Proteomics analysis revealed that c-di-GMP regulates several processes critical for virulence, including cell wall and biofilm formation, nutrient acquisition, and the type IV secretion system. Finally, Δ
bpdA
mutants exhibited altered morphology and were hypersensitive to nutrient-limiting conditions. In summary, our results indicate a vital role for c-di-GMP in allowing
Brucella
to successfully navigate stressful and shifting environments to establish intracellular infection.
Impact of Moderate Temperature Changes on Neisseria meningitidis Adhesion Phenotypes and Proteome
Authors: Lappann Martin , Otto Andreas , Brauer Madita , Becher Dörte , Vogel Ulrich , Johswich Kay
Published: September 2016

Neisseria meningitidis
, the meningococcus, bears the potential to cause life-threatening invasive diseases, but it usually colonizes the nasopharynx without causing any symptoms. Within the nasopharynx,
Neisseria meningitidis
must face temperature changes depending on the ambient air temperature. Indeed, the nasopharyngeal temperature can be substantially lower than 37°C, the temperature commonly used in experimental settings. Here, we compared the levels of meningococcal biofilm formation, autoaggregation, and cellular adherence at 32°C and 37°C and found a clear increase in all these phenotypes at 32°C suggestive of a stronger
in vivo
colonization capability at this temperature. A comparative proteome analysis approach revealed differential protein expression levels between 32°C and 37°C, predominantly affecting the bacterial envelope. A total of 375 proteins were detected. Use of database annotation or the PSORTb algorithm predicted 49 of those proteins to be localized in the outer membrane, 21 in either the inner or outer membrane, 35 in the periplasm, 56 in the inner membrane, and 208 in the cytosol; for 6 proteins, no annotation or prediction was available. Temperature-dependent regulation of protein expression was seen particularly in the periplasm as well as in the outer and inner membranes.
N
eisserial
h
eparin
b
inding
a
ntigen (NHBA), NMB1030, and adhesin complex protein (ACP) showed the strongest upregulation at 32°C and were partially responsible for the observed temperature-dependent phenotypes. Screening of different global regulators of
Neisseria meningitidis
suggested that the extracytoplasmic sigma factor σ
E
might be involved in temperature-dependent biofilm formation. In conclusion, subtle temperature changes trigger adaptation events promoting mucosal colonization by meningococci.
Treatment with Cestode Parasite Antigens Results in Recruitment of CCR2
+
Myeloid Cells, the Adoptive Transfer of Which Ameliorates Colitis
Authors: Reyes José L. , Lopes Fernando , Leung Gabriella , Mancini Nicole L. , Matisz Chelsea E. , Wang Arthur , Thomson Emma A. , Graves Nicholas , Gilleard John , McKay Derek M.
Published: September 2016

Awareness of the immunological underpinnings of host-parasite interactions may reveal immune signaling pathways that could be used to treat inflammatory disease in humans. Previously we showed that infection with the rat tapeworm,
Hymenolepis diminuta
, used as a model helminth, or systemic delivery of worm antigen (HdAg) significantly reduced the severity of dinitrobenzene sulfonic acid (DNBS)-induced colitis in mice. Extending these analyses, intraperitoneal injection of HdAg dose-dependently suppressed dextran sodium sulfate (DSS)-induced colitis, and this was paralleled by reduced gamma interferon (IFN-γ), interleukin-17 (IL-17), and tumor necrosis factor alpha (TNF-α) production and increased IL-10 production from mitogen-activated splenocytes. Treatment with HdAg resulted in a CCR2-dependent recruitment of CDllb
+
F4/80
+
Ly6C
hi
Gr-1
lo
monocyte-like cells into the peritoneum 24 h later that were predominantly programmed death ligand 1 (PD-L1) positive and CXCR2 negative.
In vitro
assays indicated that these cells were unable to suppress T cell proliferation but enhanced IL-10 and IL-4 production from activated T cells. Adoptive transfer of the HdAg-recruited monocytic cells into naive mice blocked DSS-induced colitis. These findings add to the variety of means by which treatment with parasitic helminth-derived antigens can ameliorate concomitant disease. A precise understanding of the mechanism(s) of action of HdAg and other helminth-derived antigens (and a parallel consideration of putative side effects) may lead to the development of novel therapies for human idiopathic disorders such as inflammatory bowel disease.
Uptake and Metabolism of Antibiotics Roseoflavin and 8-Demethyl-8-Aminoriboflavin in Riboflavin-Auxotrophic Listeria monocytogenes
Authors: Matern Andreas , Pedrolli Danielle , Großhennig Stephanie , Johansson Jörgen , Mack Matthias
Published: September 2016

The riboflavin analogs roseoflavin (RoF) and 8-demethyl-8-aminoriboflavin (AF) are produced by the bacteria
Streptomyces davawensis
and
Streptomyces cinnabarinus
. Riboflavin analogs have the potential to be used as broad-spectrum antibiotics, and we therefore studied the metabolism of riboflavin (vitamin B
2
), RoF, and AF in the human pathogen
Listeria monocytogenes
, a bacterium which is a riboflavin auxotroph. We show that the
L. monocytogenes
protein Lmo1945 is responsible for the uptake of riboflavin, RoF, and AF. Following import, these flavins are phosphorylated/adenylylated by the bifunctional flavokinase/flavin adenine dinucleotide (FAD) synthetase Lmo1329 and adenylylated by the unique FAD synthetase Lmo0728, the first monofunctional FAD synthetase to be described in bacteria. Lmo1329 generates the cofactors flavin mononucleotide (FMN) and FAD, whereas Lmo0728 produces FAD only. The combined activities of Lmo1329 and Lmo0728 are responsible for the intracellular formation of the toxic cofactor analogs roseoflavin mononucleotide (RoFMN), roseoflavin adenine dinucleotide (RoFAD), 8-demethyl-8-aminoriboflavin mononucleotide (AFMN), and 8-demethyl-8-aminoriboflavin adenine dinucleotide (AFAD).
In vivo
reporter gene assays and
in vitro
transcription/translation experiments show that the
L. monocytogenes
FMN riboswitch Rli96, which controls expression of the riboflavin transport gene
lmo1945
, is negatively affected by riboflavin/FMN and RoF/RoFMN but not by AF/AFMN. Treatment of
L. monocytogenes
with RoF or AF leads to drastically reduced FMN/FAD levels. We suggest that the reduced flavin cofactor levels in combination with concomitant synthesis of inactive cofactor analogs (RoFMN, RoFAD, AFMN, and AFAD) explain why RoF and AF contribute to antibiotic activity in
L. monocytogenes
.

IMPORTANCE
The riboflavin analogs roseoflavin (RoF) and 8-demethyl-8-aminoriboflavin (AF) are small molecules which are produced by
Streptomyces davawensis
and
Streptomyces cinnabarinus
. RoF and AF were reported to have antibacterial activity, and we studied how these compounds are metabolized by the human bacterial pathogen
Listeria monocytogenes
. We found that the
L. monocytogenes
protein Lmo1945 mediates uptake of AF and RoF and that the combined activities of the enzymes Lmo1329 and Lmo0728 are responsible for the conversion of AF and RoF to toxic cofactor analogs. Comparative studies with RoF and AF (a weaker antibiotic) suggest that the reduction in FMN/FAD levels and the formation of inactive FMN/FAD analogs explain to a large extent the antibiotic activity of AF and RoF.
Implementation and Data Analysis of Tn-seq, Whole-Genome Resequencing, and Single-Molecule Real-Time Sequencing for Bacterial Genetics
Authors: Burby Peter E. , Nye Taylor M. , Schroeder Jeremy W. , Simmons Lyle A.
Published: September 2016

Few discoveries have been more transformative to the biological sciences than the development of DNA sequencing technologies. The rapid advancement of sequencing and bioinformatics tools has revolutionized bacterial genetics, deepening our understanding of model and clinically relevant organisms. Although application of newer sequencing technologies to studies in bacterial genetics is increasing, the implementation of DNA sequencing technologies and development of the bioinformatics tools required for analyzing the large data sets generated remain a challenge for many. In this minireview, we have chosen to summarize three sequencing approaches that are particularly useful for bacterial genetics. We provide resources for scientists new to and interested in their application. Here, we discuss the analysis of data from transposon mutagenesis followed by deep sequencing (Tn-seq) to determine gene disruptions differentially represented in a mutant population and Illumina sequencing for identification of suppressor or other mutations, and we summarize single-molecule real-time (SMRT) sequencing forde novogenome assembly and the use of the output data for detection of DNA base modifications.
A Personal View of How Paleomicrobiology Aids Our Understanding of the Role of Lice in Plague Pandemics
Authors: Raoult Didier
Published: September 2016

We have been involved in the field of paleomicrobiology since 1998, when we used dental pulp to identify
Yersinia pestis
as the causative agent of the great plague of Marseille (1720). We recently designed a specific technique, “suicide PCR,” that can prevent contamination. A controversy arose between two teams, with one claiming that DNA must be altered to amplify it and the other group claiming that demographic data did not support the role of
Y. pestis
in the Black Death (i.e., the great plague of the Middle Ages). These controversies led us to evaluate other epidemiological models and to propose the body louse as the vector of this pandemic. This proposal was substantiated by experimental models, the recovery of
Y. pestis
from lice in the Congo, and the identification of epidemics involving both
Y. pestis
and
Bartonella quintana
(the agent of trench fever, transmitted by the body louse) in ancient corpses from mass graves. Paleomicrobiology has led to a re-evaluation of plague pandemics.
The History of Epidemic Typhus
Authors: Angelakis Emmanouil , Bechah Yassina , Raoult Didier
Published: September 2016

Epidemic typhus caused by
Rickettsia prowazekii
is one of the oldest pestilential diseases of humankind. The disease is transmitted to human beings by the body louse
Pediculus humanus corporis
and is still considered a major threat by public health authorities, despite the efficacy of antibiotics, because poor sanitary conditions are conducive to louse proliferation. Epidemic typhus has accompanied disasters that impact humanity and has arguably determined the outcome of more wars than have soldiers and generals. The detection, identification, and characterization of microorganisms in ancient remains by paleomicrobiology has permitted the diagnosis of past epidemic typhus outbreaks through the detection of
R. prowazekii
. Various techniques, including microscopy and immunodetection, can be used in paleomicrobiology, but most of the data have been obtained by using PCR-based molecular techniques on dental pulp samples. Paleomicrobiology enabled the identification of the first outbreak of epidemic typhus in the 18th century in the context of a pan-European great war in the city of Douai, France, and supported the hypothesis that typhus was imported into Europe by Spanish soldiers returning from America.
R. prowazekii
was also detected in the remains of soldiers of Napoleon’s Grand Army in Vilnius, Lithuania, which indicates that Napoleon’s soldiers had epidemic typhus. The purpose of this article is to underscore the modern comprehension of clinical epidemic typhus, focus on the historical relationships of the disease, and examine the use of paleomicrobiology in the detection of past epidemic typhus outbreaks.
Past Intestinal Parasites
Authors: Le Bailly Matthieu , Araújo† Adauto
Published: September 2016

This chapter aims to provide some key points for researchers interested in the study of ancient gastrointestinal parasites. These few pages are dedicated to my colleague and friend, Prof. Adauto Araújo (1951-2015), who participated in the writing of this chapter. His huge efforts in paleoparasitology contributed to the development and promotion of the discipline during more than 30 years.
Demographic Patterns Distinctive of Epidemic Cemeteries in Archaeological Samples
Authors: Castex Dominique , Kacki Sacha
Published: September 2016

The analysis of biological parameters such as age and sex is particularly relevant to the interpretation of ancient skeletal assemblages related to abrupt mortality crises, and more particularly epidemics. In such a context, the mechanisms of selection within a population or part of a population differ according to the pathogen involved. They may also vary depending on the period and location in which the population lived. Here, we illustrate the specificity of plague mortality through the study of several European burial sites contemporary with the first and second plague pandemics. The paleodemographic patterns obtained for different plague outbreaks from the 6th to the 16th centuries reveal some constant features over time and space as well as some differences that suggest a possible evolution in the epidemiological characteristics of the disease.
Paleomicrobiology Data: Authentification and Interpretation
Authors: Drancourt Michel
Published: September 2016

The authenticity of some of the very first works in the field of paleopathology has been questioned, and standards have been progressively established for the experiments and the interpretation of data. Whereas most problems initially arose from the contamination of ancient specimens with modern human DNA, the situation is different in the field of paleomicrobiology, in which the risk for contamination is well-known and adequately managed by any laboratory team with expertise in the routine diagnosis of modern-day infections. Indeed, the exploration of ancient microbiota and pathogens is best done by such laboratory teams, with research directed toward the discovery and implementation of new techniques and the interpretation of data.
Cardiorespiratory fitness cut points to avoid cardiovascular disease risk in children and adolescents; what level of fitness should raise a red flag? A systematic review and meta-analysis
Authors: Ruiz Jonatan R , Cavero-Redondo Ivan , Ortega Francisco B , Welk Gregory J , Andersen Lars B , Martinez-Vizcaino Vicente
Published: September 2016

Background

Poor cardiorespiratory fitness is associated with cardiovascular disease risk factors.

Aim

To perform a systematic review and meta-analysis of the relationship between poor cardiorespiratory fitness and cardiovascular disease risk in children and adolescents.

Methods

Systematic literature search (1980 to 11 April 2015) for studies that determined a cardiorespiratory fitness cut point that predicted cardiovascular disease risk in children and adolescents.

Results

We identified 7 studies that included 9280 children and adolescents (49% girls) aged 8–19 years from 14 countries. Cardiovascular disease risk was already present in boys (6–39%) and girls (6–86%). Boys with low fitness (<41.8 mL/kg/min) had a 5.7 times greater likelihood of having cardiovascular disease risk (95% CI 4.8 to 6.7). The comparable diagnostic OR for girls with low fitness (<34.6 mL/kg/min) was 3.6 (95% CI 3.0 to 4.3). The 95% confidence region of cardiorespiratory fitness associated with low cardiovascular disease risk ranges, 41.8–47.0 mL/kg/min in boys (eg, stages 6–8 for a boy aged 15 years) and 34.6–39.5 mL/kg/min in girls (eg, stages 3–5 for a girl aged 15 years). The cardiorespiratory fitness cut point to avoid cardiovascular disease risk ranged 41.8 mL/kg/min in boys and was 34.6 mL/kg/min in girls.

Fitness levels below 42 and 35 mL/kg/min for boys and girls, respectively, should raise a red flag. These translate to 6 and 3 stages on the shuttle run test for a boy and a girl, both aged 15 years, respectively. These cut points identify children and adolescents who may benefit from primary and secondary cardiovascular prevention programming.
Burden assessment of podoconiosis in Wayu Tuka woreda, east Wollega zone, western Ethiopia: a community-based cross-sectional study
Authors: Bekele Kenate , Deribe Kebede , Amberbir Tsige , Tadele Geleta , Davey Gail , Samuel Abdi
Published: September 2016

Objective

Podoconiosis is a neglected tropical disease characterised by a slowly progressive swelling of the foot and lower leg. It is prevalent among subsistence barefoot farmers who live and work in highland areas of the tropics. This study was conducted in Wayu Tuka ‘woreda’ (district), western Ethiopia to determine the prevalence of podoconiosis and assess factors associated with acute adenolymphangitis (ALA) episodes.

Methods and analysis

A two phase, community-based cross-sectional study was conducted between January and March 2015. First, all households in the district were surveyed to determine the prevalence of podoconiosis. This was followed by a second phase in which 366 people with podoconiosis from four randomly selected ‘kebeles’ (subdistricts) were assessed for clinical features of the disease, shoe-wearing habits, personal hygiene, social stigma and functional impairment. Data entered into Epi DATA were then exported to SPSS. Logistic regression analysis was conducted to identify factors associated with ALA.

Results

Prevalence of podoconiosis in the population was 3.05% (1197/39 256) (95% CI 2.9% to 3.2%). The prevalence was significantly higher among women than men (3.67% vs 2.4%). Most (92.2%) people with podoconiosis were in the economically active age group (15–64 years) in the first phase survey. Of participants in the second phase of the study, 43% had stage 2 disease and 38.1% had ‘moss’-like skin changes. On average, people with podoconiosis had 23.3 episodes of ALA/year and each person with podoconiosis lost 149.5 days of activity/year. Never walking barefoot and daily foot washing were both associated with decreased odds of ALA (AOR=0.23; 95% CI 0.06 to 0.80 and 0.09; 95% CI 0.01 to 0.75, respectively).

Conclusions

A relatively high prevalence of podoconiosis, frequent ALA episodes and considerable decreases in daily activities were identified in this district. Footwear use and daily foot hygiene were associated with decreased odds of ALA. We recommend prevention and morbidity management interventions to address this developmental challenge.
Data sharing through an NIH central database repository: a cross-sectional survey of BioLINCC users
Authors: Ross Joseph S , Ritchie Jessica D , Finn Emily , Desai Nihar R , Lehman Richard L , Krumholz Harlan M , Gross Cary P
Published: September 2016

Objective

To characterise experiences using clinical research data shared through the National Institutes of Health (NIH)'s Biologic Specimen and Data Repository Information Coordinating Center (BioLINCC) clinical research data repository, along with data recipients’ perceptions of the value, importance and challenges with using BioLINCC data.

Design and setting

Cross-sectional web-based survey.

Participants

All investigators who requested and received access to clinical research data from BioLINCC between 2007 and 2014.

Main outcome measures

Reasons for BioLINCC data request, research project plans, interactions with original study investigators, BioLINCC experience and other project details.

Results

There were 536 investigators who requested and received access to clinical research data from BioLINCC between 2007 and 2014. Of 441 potential respondents, 195 completed the survey (response rate=44%); 89% (n=174) requested data for an independent study, 17% (n=33) for pilot/preliminary analysis. Commonly cited reasons for requesting data through BioLINCC were feasibility of collecting data of similar size and scope (n=122) and insufficient financial resources for primary data collection (n=76). For 95% of respondents (n=186), a primary research objective was to complete new research, as opposed to replicate prior analyses. Prior to requesting data from BioLINCC, 18% (n=36) of respondents had contacted the original study investigators to obtain data, whereas 24% (n=47) had done so to request collaboration. Nearly all (n=176; 90%) respondents found the data to be suitable for their proposed project; among those who found the data unsuitable (n=19; 10%), cited reasons were data too complicated to use (n=5) and data poorly organised (n=5). Half (n=98) of respondents had completed their proposed projects, of which 67% (n=66) have been published.

Conclusions

Investigators were primarily using clinical research data from BioLINCC for independent research, making use of data that would otherwise have not been feasible to collect.
Knowledge, beliefs and attitudes of Muslim footballers towards Ramadan fasting during the London 2012 Olympics: a cross-sectional study
Authors: Farooq Abdulaziz , Herrera Christopher P , Zerguini Yacine , Almudahka Fuad , Chamari Karim
Published: September 2016

Objectives

Muslims observe fasting during the month of Ramadan by abstaining from eating and drinking from dawn to sunset. Available literature shows that although several studies have been conducted on athletes to determine the effects of Ramadan fasting in terms of physical fitness and performance, little data are available regarding the knowledge, beliefs and attitudes of athletes (particularly footballers) towards Ramadan fasting during high-level competitions. This study explored the knowledge, beliefs and attitudes towards Ramadan fasting among football players participating in the London 2012 Olympics football tournament.

Design

Cross-sectional study.

Settings

Team training facility.

Participants

54 Muslim footballers participating in the London Olympics, 2012

Outcome measures

Each participant was asked to complete a pre-validated structured questionnaire to assess knowledge, beliefs and attitudes regarding Ramadan fasting and their intention to fast during London 2012.

Results

Of the 54 participating athletes, 21(39%) reported that they intended to fast during Ramadan, but not on a match day. This attitude differed across three teams interviewed —83%, 15% and 0%—showing cross-cultural variation. Overall, there was a lack of knowledge among footballers regarding the effects of Ramadan fasting on sleep and performance; around 30% of athletes gave incorrect responses. This knowledge was independent of their decision to fast on non-competition days (p>0.05).

Conclusions

This is the first study to describe the knowledge, beliefs and attitudes towards Ramadan fasting among athletes from Muslim-majority countries participating in a high-level competition. Appropriate knowledge can ensure optimum performance for athletes during Ramadan fasting. Coaches, family members and friends also in possession of this knowledge can provide moral support to the players.
Is tuberculosis health education reaching the public in China? A cross-sectional survey in Guizhou Province
Authors: Chen Wei , Li Yang , Yang Haiqin , Ehiri John , Chen Zaiping , Liu Ying , Wang Mei , Liu Shili , Tang He , Li Ying
Published: September 2016

Background

Knowledge about tuberculosis (TB) is important for TB control, and China's national TB control guidelines emphasise TB health promotion. A 2010 national TB epidemiology survey showed that the general public had limited knowledge and awareness of TB.

Objective

To assess the level of TB knowledge after 5 years of TB health promotion in Guizhou Province, one of the regions with the highest TB burden in China.

Design and setting

A community-based, cross-sectional survey of 10 237 residents of Guizhou Province from June to August 2015. Multiple logistic regression models were used to examine factors associated with core TB knowledge and TB health education among respondents.

Results

Overall, residents of Guizhou Province had inadequate knowledge of TB. The overall awareness of TB was 41.5%. Less than 30% of respondents were familiar with China's policy of free treatment for TB or knew that the disease could be cured. Factors associated with core TB knowledge included gender, age, ethnicity, education, occupation, region, and having received TB health education. Women, older adults, people employed in non-government institutions, and those living in counties with low TB burdens had little access to TB health education, whereas people with higher education levels had greater access. Respondents' sources of TB knowledge did not necessarily match their preferred channels for delivery of TB health education.

Conclusions

Our findings indicate that TB health education should be further strengthened in China and other countries with a high TB burden. TB health education programmes require further formative and implementation research in order to improve programme effectiveness.
Diluted honey inhibits biofilm formation: potential application in urinary catheter management?
Authors: Emineke Somadina , Cooper Alan J , Fouch Sarah , Birch Brian R , Lwaleed Bashir A
Published: September 2016

Aims

Biofilms are ubiquitous and when mature have a complex structure of microcolonies in an extracellular polysaccharide and extracellular DNA matrix. Indwelling medical devices harbour biofilms which have been shown to cause infections and act as reservoirs for pathogens. Urinary catheters are often in place for considerable periods of time and are susceptible to both encrustation and biofilm formation. Strategies for minimising biofilm occurrence underpin an active research area in biomedicine. Manuka honey has, inter alia,well-established antibacterial properties. This study aims to assess the influence of honey on early biofilm formation in an established in vitro model.

Methods

An established model of early biofilm formation using static bacterial cultures in vinyl 96-well plates was used to growEscherichia coli, strain ATC 25922 andProteus mirabilis, strain 7002. Planktonic cells were removed and the residual biofilm was stained with crystal violet, which were subsequently eluted and quantified spectrophotometrically. Manuka honey (Unique Manuka Factor 15+) was added either with the bacteria or up to 72 hours after.

Results

Biofilms in this model was developed over 3 days, after which growth stalled. Mixed (1:1) cultures ofE. coliandP. mirabilisgrew slower than monocultures. In mixed cultures, honey gave a dose-dependent reduction in biofilm formation (between 3.3 and 16.7%w/v). At 72 hours, all concentrations inhibited maximally (p<0.001). Application of honey to cultures after 24 and 48 hours also reduced the adherent bacterial biomass (p<0.05–p<0.01).

Conclusion

Manuka honey at dilutions as low as 3.3% w/v in some protocols and at 10% or above in all protocols tested significantly inhibits bacterial attachment to a vinyl substrate and reduces further early biofilm development. No augmentation of growth over untreated controls was observed in any experiment.
The role of miRNA-21 and epithelial mesenchymal transition (EMT) process in colorectal cancer
Authors: Jaca Anelisa , Govender Padmini , Locketz Michael , Naidoo Richard
Published: September 2016

Aims

The study was conducted to assess the expression levels of epithelial mesenchymal transition (EMT) proteins (E-cadherin, N-cadherin, snail-1 and vimentin) and miRNA-21. In addition, we correlated these data with clinicopathological features in Colorectal cancer.

Methods

H&E slides from a total of 59 formalin fixed paraffin embedded tissue blocks were examined by a pathologist to demarcate normal and tumour regions. Immunohistochemical analysis of mismatch repair proteins (MLH1, MSH2 and MSH6) and EMT markers (E-cadherin, N-cadherin, snail-1 and vimentin) was performed. The miRNA-21 expression levels were determined using qRT-PCR and the data was analysed using the relative quantification method. The Fisher's exact and Pearson's χ2tests were used to correlate snail-1, E-cadherin, miRNA-21 and clinicopathological data.

Results

Our results showed a statistically significant correlation between high miRNA-21 expression levels and E-cadherin positive cases. There was also an association between high miRNA-21 expression levels and negative snail-1 expression. No significant correlation was seen between miRNA-21 expression levels and clinicopathological features. Moreover, high expression levels of miRNA-21 were significantly associated with the sporadic cases.

Conclusions

Our data suggest that miRNA-21 in association with E-cadherin and snail-1 does not play a significant role in the development and progression of this disease.
A rare but morbid neurosurgical target: petrous aneurysms and their endovascular management in the stent/flow diverter era
Authors: Gross Bradley A , Moon Karam , Ducruet Andrew F , Albuquerque Felipe C
Published: September 2016

Background/objective

The rarity of petrous internal carotid artery (ICA) aneurysms has largely precluded analyses of their presentation and management in case series format.

Methods

We performed a retrospective analysis of our endovascular database of patients treated from January 2001 to May 2016 to identify patients with petrous ICA aneurysms. We evaluated the treatment approach and results for patients managed in the era of dedicated intracranial stents and flow diverters, noting clinical and angiographic results.

Results

Our database search identified 10 patients with petrous ICA aneurysms. Six aneurysms were managed in the era of dedicated intracranial stents and flow diverters. Two patients presented with cranial nerve palsies, two with incidental but enlarging aneurysms that had completely eroded through the petrous bone, one with transient ischemic attacks, and one with pulsatile tinnitus. Five aneurysms were large and one was small but symptomatic. In three cases the aneurysm was treated by flow diversion with adjunctive coiling; two patients with at least 4-month follow-up had complete occlusion of their aneurysm and significant improvement of mass effect symptoms. In one case the aneurysm was treated with balloon-assisted coiling with resultant near-complete occlusion. In two cases, prior to the introduction of flow diverters, the aneurysm was treated via stent-assisted coiling with resultant near-complete obliteration; one patient had resolution of pretreatment pulsatile tinnitus. There were no intraprocedural or postprocedural complications; no patients underwent retreatment.

Conclusions

Endovascular treatment of large or symptomatic petrous ICA aneurysms, in the era of flow diversion, is associated with excellent angiographic and clinical outcomes.
The renin-angiotensin-aldosterone system in heart failure for the non-specialist: the past, the present and the future
Authors: Orsborne Christopher , Chaggar Parminder S , Shaw Steven M , Williams Simon G
Published: September 2016

Heart failure is one of the major public health challenges facing the Western world. Its prevalence is increasing as the population ages and modern techniques are implemented to manage cardiac disease. In response, there has been a sustained effort to develop novel strategies to address the high levels of associated morbidity and mortality. Indeed, agents that target the renin-angiotensin-aldosterone system (RAAS) have transformed the way in which we manage heart failure. Despite this, mortality in heart failure is poorer than in many malignancies and a large burden of morbidity and recurrent hospitalisation remains. Here, we review the role of RAAS modulation within the field of systolic heart failure. In particular, we provide practical guidance on using current RAAS blockade agents and focus on the recent emergence of new agents that promise additional substantial benefit to those living with left ventricular systolic dysfunction.
Root-endophytic fungi cause morphological and functional differences in Scots pine roots in contrast to ectomycorrhizal fungi
Authors: Heinonsalo Jussi , Buée Marc , Vaario Lu-Min
Published: September 2016

Endophytic fungi and ectomycorrhizal fungi co-exist in the mycorrhizal root tips of boreal forest trees. However, very little is known about the functional role they play in their host’s biology. The activity of enzymes responsible for important biochemical processes is used to determine the functional role of root-associated mycorrhizal fungi. However, enzyme activity is never studied in the presence of endophytic fungi in-planta. The aims of this study were to investigate the effect of Scots pine (Pinus sylvestris L.) root-isolated fungal endophytes on the host plant root morphology, to determine their functional effects using host root-excreted enzyme activity measurements, and to compare them with roots colonized by decomposer and ectomycorrhizal fungal strains and noncolonised Scots pine root tips. Our results show that endophytic fungi did not damage the pine roots in contrast to the decomposer fungi. The endophytic fungi penetrated the cortical cells of the host plant. The roots colonised by endophytic fungi produce different exo-enzymes compared with those produced by roots colonized by other fungal groups or noncolonized control root tips. Our results indicate that endophytic fungi are clearly a distinctive ecological group of fungi that have functional traits different from those of ectomycorrhizal and decomposer fungi.
Parentage of Archean basement within a Paleoproterozoic orogen and implications for on-craton diamond preservation: Slave craton and Wopmay orogen, northwest Canada
Authors: Ootes Luke , Jackson Valerie A. , Davis William J. , Bennett Venessa , Smar Leanne , Cousens Brian L.
Published: September 2016

The Wopmay orogen is a Paleoproterozoic accretionary belt preserved to the west of the Archean Slave craton, northwest Canada. Reworked Archean crystalline basement occurs in the orogen, and new bedrock mapping, U–Pb geochronology, and Sm–Nd isotopic data further substantiate a Slave craton parentage for this basement. Detrital zircon results from unconformably overlying Paleoproterozoic supracrustal rocks also support a Slave craton provenance. Rifting of the Slave margin began at ca. 2.02 Ga with a second rift phase constrained between ca. 1.92 and 1.89 Ga, resulting in thermal weakening of the Archean basement and allowing subsequent penetrative deformation during the Calderian orogeny (ca. 1.88–1.85 Ga). The boundary between the western Slave craton and the reworked Archean basement in the southern Wopmay orogen is interpreted as the rifted cratonic margin, which later acted as a rigid backstop during compressional deformation. Age-isotopic characteristics of plutonic phases track the extent and evolution of these processes that left penetratively deformed Archean basement, Paleoproterozoic cover, and plutons in the west, and “rigid” Archean Slave craton to the east. Diamond-bearing kimberlite occurs across the central and eastern parts of the Slave craton, but kimberlite (diamond bearing or not) has not been documented west of ∼114°W. It is proposed that while the crust of the western Slave craton escaped thermal weakening, the mantle did not and was moved out of the diamond stability field. The Paleoproterozoic extension–convergence cycle preserved in the Wopmay orogen provides a reasonable explanation as to why the western Slave craton appears to be diamond sterile.
Experimental and field evaluation of otolith strontium as a marker to discriminate between river-spawning populations of walleye in Lake Erie
Authors: Chen Kuan-Yu , Ludsin Stuart A. , Corey Morgan M. , Collingsworth Paris D. , Nims Megan K. , Olesik John W. , Dabrowski Konrad , van Tassell Jason J. , Marschall Elizabeth A.
Published: September 2016

Otolith microchemistry is a commonly used tool for stock discrimination in fisheries management. Two key questions remain with respect to its effectiveness in discriminating among river-spawning populations. First, do larvae remain in their natal river long enough for their otoliths to pick up that system’s characteristic chemical signature? Second, are larval otolith microchemical differences between natal rivers sufficiently large to overcome spatiotemporal variation in water chemistry? We quantified how larval age, the ratio of ambient strontium to calcium concentrations (Sr:Ca), and water temperature influence otolith Sr in both lab-reared and wild-collected Lake Erie walleye (Sander vitreus). Otolith microchemistry shows promise as a spawning stock discrimination tool, given that otolith Sr in larval walleye (i) is more strongly influenced by ambient Sr:Ca than by temperature; (ii) reflects Sr:Ca levels in the natal environment, even in larvae as young as 2 days old; and (iii) can effectively discriminate between larvae captured in two key Lake Erie spawning tributaries, even in the face of short larval river residence times and within-year and across-year variation in ambient Sr:Ca.
Linking LiDAR with streamwater biogeochemistry in coastal temperate rainforest watersheds
Authors: Fellman Jason B. , Buma Brian , Hood Eran , Edwards Richard T. , D’Amore David V.
Published: September 2016

The goal of this study was to use watershed characteristics derived from light detection and ranging (LiDAR) data to predict stream biogeochemistry in Perhumid Coastal Temperate Rainforest (PCTR) watersheds. Over a 2-day period, we sampled 37 streams for concentrations of dissolved C, N, P, major cations, and measures of dissolved organic matter quality (specific ultraviolet absorbance, SUVA254) and bioavailability. Random forest – classification and regression tree analysis showed that aboveground biomass and structure and watershed characteristics, inclusive of mean watershed slope and elevation, watershed size, and topographic wetness, explained more than 60% of the variation in concentration for most measured constituents. These results indicate this approach may be particularly useful for predicting stream biogeochemistry in small forested watersheds where fine resolution is needed to resolve subtle differences in forest biomass, structure, and topography. Overall, we suggest that the use of LiDAR in many of the small and remote watersheds across the Southeast Alaskan PCTR as well as other forested regions could help inform land management decisions that have the potential to alter ecosystems services related to watershed biogeochemical fluxes.
Biomass equations for lodgepole pine in northern Sweden
Authors: Elfving Björn , Ulvcrona Kristina Ahnlund , Egnell Gustaf
Published: September 2016

Biomass equations for cultivated lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) were developed based on data from destructive biomass sampling of 164 trees collected from 13 sites at latitudes 61.9°N–66.2°N in northern Sweden. Stand age varied between 20 and 87 years and top height varied between 8 and 32 m. Seeded and planted stands with different densities were included. Allometric biomass equations for all above-stump components were constructed, expressing dry mass of stem, bark, living and dead branch wood, foliage, and cones, as well as total mass. Equations with one to three independent variables were constructed for each component, accounting for variances within and between sites. Estimated values for trees of different sizes were compared with corresponding estimates for lodgepole pine in Canada and Scots pine (Pinus sylvestris L.) in Sweden and Finland. Residual variation of our equations was lower than that of equations from other sources. Our equations predicted average biomass levels similar to the predictions from Canadian equations for natural stands. In comparison with Scots pine, at given stem dimensions, lodgepole pine had 50%–100% more foliage biomass and greater dead branch biomass with increasing tree size. The wide amplitude of our data and the flexible form of our equations should make them useful for wider application.
Variability in aboveground carbon driven by slope aspect and curvature in an eastern deciduous forest, USA
Authors: Smith Lauren A. , Eissenstat David M. , Kaye Margot W.
Published: September 2016

In forested ecosystems, topography and tree species contribute to spatial variability in carbon (C) dynamics through differential rates of C uptake and storage; therefore, estimates of species-specific and spatial variability in C can strengthen ecosystem budgets. To produce such estimates, we deconstructed watershed-scale C and component pools (e.g., wood biomass, litter) and fluxes at a fine scale using a small mixed deciduous forest catchment to determine the variation due to topographic position and species. Factors affecting fluxes included aspect, slope curvature, tree species contributions, and litter production. Annual C uptake into wood varied across the catchment from 0 to 34 kg C·year−1 and was 20% greater on southern aspects than northern ones and 33% greater in swales than non-swale slopes. Of the more than 20 tree species found in the forest canopy of the catchment, highest C uptake in woody biomass was measured in Quercus rubra L. growing in swales, followed by Quercus prinus L. syn. growing on the southern aspect, with the lowest aboveground wood increment measured in Pinus at higher elevations on non-swale slopes. Quercus leaf litter moved from where it dropped into litter traps to where it settled on the forest floor, shifting the location of litter C inputs to the soil. Local variation in aboveground C rivals regional variation across regions and has the potential to introduce error when scaling C measures from points to landscapes.