bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of exposure to electromagnetic field on rat myocardium
Authors: Kiray Amac , Tayefi Hamid , Kiray Muge , Bagriyanik Husnu Alper , Pekcetin Cetin , Ergur Bekir Ugur , Ozogul Candan
Published: February 2012

Exposure to electromagnetic fields (EMFs) causes increased adverse effects on biological systems. The aim of this study was to investigate the effects of EMF on heart tissue by biochemical and histomorphological evaluations in EMF-exposed adult rats. In this study, 28 male Wistar rats weighing 200–250 g were used. The rats were divided into two groups: sham group ( n = 14) and EMF group ( n = 14). Rats in sham group were exposed to same conditions as the EMF group except the exposure to EMF. Rats in EMF group were exposed to a 50-Hz EMF of 3 mT for 4 h/day and 7 days/week for 2 months. After 2 months of exposure, rats were killed; the hearts were excised and evaluated. Determination of oxidative stress parameters was performed spectrophotometrically. To detect apoptotic cells, terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling (TUNEL) staining and caspase-3 immunohistochemistry were performed. In EMF-exposed group, levels of lipid peroxidation significantly increased and activities of superoxide dismutase and glutathione peroxidase decreased compared with sham group. The number of TUNEL-positive cells and caspase-3 immunoreactivity increased in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. In conclusion, the results show that the exposure to EMF causes oxidative stress, apoptosis and morphologic damage in myocardium of adult rats. The results of our study indicate that EMF-related changes in rat myocardium could be the result of increased oxidative stress. Further studies are needed to demonstrate whether the exposure to EMF can induce adverse effects on myocardium.
Citric acid production from Aspergillus niger MT-4 using hydrolysate extract of the insect Locusta migratoria
Authors: Taskin Mesut , Tasar Gani Erhan , Incekara Umit
Published: February 2012

Citric acid (CA) is the most important organic acid used in the food and other industries. Locusta migratoria is an insect species, which has rich nutritional composition (especially protein) and cultivated in some countries. Therefore, the present study investigated the usability of hydrolysate extract of L. migratoria biomass as substrate for the production of CA from Aspergillus niger MT-4. The insect extract (IE) was found to be rich in ash (34.9 g/100 g), protein (35.6 g/100 g) and mineral contents. Yeast extract was found to be the most favorable substrate for biomass production, whereas the maximum production of CA (41.8 g/L) was achieved in the medium containing IE. Besides, uniform pellets with the smallest size (4 mm) were observed in IE medium. It was thought that rich magnesium (6.78 g/100 g) and manganese (1.14 g/100 g) contents of IE increased the production of CA, resulting in the formation of small uniform pellets. This is the first report on the effect of protein-rich insect biomasses on the production of CA. In this regard, L. migratoria biomass was tested for the first time as a CA-production substrate.
Fusion bonding of structural T-joints for thermoplastic composite boats
Authors: Otheguy ME , Gibson AG , Robinson AM
Published: February 2012

This article presents an experimental study of fusion-bonded polypropylene (PP) glass composite joints in the context of small craft manufacture. The objective is to investigate the manufacturing of lap joints and T-joints as a structural part of a small boat and study their properties, because a joining technique is a fundamental requirement of any boat construction technology. Results show that PP interlayers improve bond quality for both lap joints and T-joints and that woven precursor materials are preferred for T-joint manufacturing. It was also found that this technique produces higher lap shear strength values than adhesives and resistance welding, and that pull-out strength values were comparable with those of thermosetting designs, demonstrating that fusion bonding is a suitable joining technique for thermoplastic composite craft.
Morphological changes and surface reactions of wood fibers in wood composites
Authors: Gu Ruijun , Sain Mohini M , Kokta Bohuslav V
Published: February 2012

This work addressed questions regarding the fate of wood pulp fibers in the composite manufacturing process, for instance whether the processing induced fiber damages, and the improved interfacial adhesion accelerated this function. A number of wood fibers were blended with various maleic anhydride-grafted polymers fully and partially to study their morphological changes. The fractured fibers were separated from wood composites with aromatic hydrocarbons and analyzed using Fiber quality analyses, Scanning electron microscope, Fourier transform infrared analysis and X-ray photoelectron spectroscopy to validate the degree of fiber fractures and the esterification reaction. The fiber damages were related to the maleic anhydride grafting degree, molecular weight and molecular structures of maleated polymers.
Analysis of coupled residual stresses in stamping and welding processes by finite element methods
Authors: Kang Woojong , Cheon Seong S
Published: February 2012

Residual stress distribution in an automotive component produced by forming and welding processes has been predicted by finite element methods. Multi-step process simulations have been synthesized to predict the coupled residual stresses. For the qualitative verification of the distribution, a neutron diffraction detection technique is adopted for residual stress measurement. Stamping simulation is carried out first and the results are mapped onto the mesh for welding simulation. Springback simulation is also performed to estimate the stamping residual stress distribution. Although the welding phenomenon is complex in the construction of a model, a simple simulation model is proposed with several assumptions and verified with experimental results. Temperature-dependent material properties are used for the welding simulation. Stress–strain relations on various temperatures are obtained from the Johnson–Cook model of SAPH380. Each process simulation result is compared with a measured one and a good correlation is achieved. The high residual stresses in the wall area of the sample can be successfully predicted with the sequential stamping and welding simulation. From simulation results, large weld residual stresses are obtained when the stamping effects are included, but not as large as the linear summation of weld and stamping residual stresses. The stamping or welding simulation alone cannot predict the large wall stress generation on the final product, but the sequential non-linear simulation successfully predicts the high stresses at the wall region.
Smooth control over jerk with displacement constraint
Authors: Storey Ian , Bourmistrova Anna , Subic Aleksandar
Published: February 2012

This article investigates the problem of using jerk (the rate-of-change of acceleration) motion control to move a given distance without overshoot. Distance, velocity, and acceleration are all brought to zero simultaneously. Although this problem has been identified in suspension control, it may also be of interest in mechatronics. In this research, particular controls were found that solved this problem. An algorithm was developed which is stable when used in a discretized form, as in a microprocessor continually updated with current state estimations. The control was found serendipitously. A wider range of controls is conjectured to provide the solution to the general minimum-time control problem under distance and jerk constraints. To describe these controls, they are here referred to as ‘skim’ controls. Also, a ‘bang-off-bang’ variant was developed and this was used in a simple test rig. The test developed in this research supports the utility and robustness of the control method.
Experimental investigation of pressure distribution between the piston rings and its formation in reciprocating compressors
Authors: Xin Dianbo , Feng Jianmei , Ding Liqing , Yang Donghui , Peng Xueyuan
Published: February 2012

The severe non-uniformity of pressure distribution has been suggested as the essential reason for the premature failure of piston rings in reciprocating compressors. A test rig was built to investigate the dynamic pressure distribution and its formation process, so that the root cause of the non-uniform pressure distribution could be revealed. The experimental results showed that the pressure distribution between the rings was always significantly non-uniform under various test conditions and the first ring bore more than 75% of the total pressure difference. Further analysis of the experimental data indicated that when the suction pressure was not higher than that in the crank case, the first piston ring switched its contact position with the piston ring groove twice in one cycle, at the angles of around 63° and 170°, respectively, while the others switched contact positions at about 90° and 270°. If the suction pressure was higher than the pressure in the crank case, the first ring still switched its contact position twice in a cycle, at the crank angle of about 47° and 195°, respectively, but the other rings no longer changed their positions. The experimental results also demonstrated that the formation of pressure difference on different rings was not synchronous, which indicated that the rings could not work until their pressure difference reached a critical value.
Anti-ganglioside antibodies in patients with systemic lupus erythematosus and neurological manifestations
Authors: Labrador-Horrillo M , Martinez-Valle F , Gallardo E , Rojas-Garcia R , Ordi-Ros J , Vilardell M
Published: February 2012

Introduction: Anti-ganglioside antibodies (AGA) have been associated with several peripheral neuropathies, such as Miller–Fisher syndrome, Guillain–Barré syndrome and multifocal motor neuropathy. They have also been studied in patients with systemic lupus erythematosus (SLE), focusing on neuropsychiatric manifestations and peripheral neuropathy, but the results are contradictory. Objective: To study the presence of AGA in a large cohort of patients with SLE and neuropsychiatric manifestations. Patients and methods: Serum from 65 consecutive patients with SLE and neuropsychiatric manifestations, collected from 1985 to 2009, was tested for the presence of AGA antibodies (GM1, GM2, GM3, asialo-GM1 GD1a, GD1b, GD3, GT1b, GQ1b) using a standard enzyme-linked immunosorbent assay ELISA test (INCAT 1999) and thin layer chromatography (TLC). Results: Positive results for asialo-GM1 (IgM) were found in 10 patients, 6 were positive for asialo-GM1 (IgM and IgG), and 4 were positive for other AGA such as GM1, GM2, GM3, GD1b, GT1b, GD3, (mainly IgM). Conclusions: Clinical and statistical studies showed no correlation between AGA and neuropsychiatric manifestations of SLE. Although some patients showed reactivity to AGA, these antibodies are not a useful marker of neuropsychiatric manifestations in SLE patients.
The Crown in a Multicultural Age: The Changing Epistemology of (Post)colonial Sovereignty
Authors: Valverde Mariana
Published: February 2012

In Canada as in other (post)colonial settings, courts have been facing the challenging task of redefining both substantive aboriginal legal rights and evidentiary rules that now look ethnocentric. Recent litigation has shown that while rights claims made by indigenous collectives are difficult to make and sustain in court, the newly revived doctrine of the Crown’s inherent ‘honour’ can work for aboriginal peoples precisely because the Crown’s honour is, as it were, self-acting. But the neo-medieval discourse of the Crown coexists, in the text of Canadian courts, with discursive practices that enact a contemporary, pluralistic, socially aware form of judicial anthropology. These two wholly conflicting representations of the Canadian state live happily side by side in current Canadian judicial discourse. This easy eclecticism stands in marked contrast to the difficulties and embarrassments experienced by aboriginal leaders testifying before judges. The close judicial scrutiny of aboriginal claims contrasts with the tolerance of major epistemological contradictions in the state’s discourses about itself.
Nurses serving on clinical ethics committees
Authors: Cusveller Bart
Published: February 2012

The competency profile underlying higher nursing education in the Netherlands states that bachelor-prepared nurses are expected to be able to participate in ethics committees. What knowledge, skills and attitudes are involved in this participation is unclear. In five consecutive years, groups of two to three fourth-year (bachelor) nursing students conducted 8 to 11 semi-structured interviews each with nurses in ethics committees. The question was what competencies these nurses themselves say they need to participate in such committees. This article reports the aggregate of the 52 interviews in these five studies. Regarding knowledge, the article reports on health law, ethics and professional knowledge. Regarding skills, communication is mentioned, as are professional skills and skills for ‘doing ethics’. An open and respectful attitude towards patients and fellow committee members is required, as well as commitment to patient care, committee work and professional ethics. The right attitude for a nurse in an ethics committee is said to include a reflective and perceptive attitude, along with an awareness of one’s own limitations and convictions. A detailed competency profile for nurses’ participation in ethics committees as outlined in the recommendations may serve nursing education, institutional committees and nurses themselves to meet the demands of nurses’ preparation for clinical ethics consultations.
Nurses’ perceptions of patient participation in hemodialysis treatment
Authors: Aasen Elin Margrethe , Kvangarsnes Marit , Heggen Kåre
Published: February 2012

The aim of this study is to explore how nurses perceive patient participations of patients over 75 years old undergoing hemodialysis treatment in dialysis units, and of their next of kin. Ten nurses told stories about what happened in the dialysis units. These stories were analyzed with critical discourse analysis. Three discursive practices are found: (1) the nurses’ power and control; (2) sharing power with the patient; and (3) transferring power to the next of kin. The first and the predominant discursive practice can be explained with an ideology of paternalism, in which the nurses used biomedical explanations and the ethical principle of benefice to justify their actions. The second can be explained with an ideology of participation, in which the nurses used ethical narratives as a way to let the patients participate in the treatment. The third seemed to involve autonomous decision-making and the ethical principle of autonomy for the next of kin in the difficult end-of-life decisions.
Rapidly progressive colonic dysplasia/neoplasia in a series of treated lung cancer patients: Is paclitaxel involved?
Authors: Kaur Antarpreet , Dasanu Constantin A
Published: February 2012

Incidence of second malignancies in patients with advanced lung cancer is not well-studied, in part because of a short survival in this patient population. Apart from a genetic predisposition, various environmental hazards may also be at play in their pathogenesis. Chronic smoking exposure decreases T-cell responsiveness and stimulates production of a variety of inhibitory cytokines. Paclitaxel has been associated with several immunosuppressive effects such as decreased numbers and activity of dendritic cells, NK-cells, and monocytes. We herein describe the first series of lung cancer patients who developed colonic polyps/colon cancer either during or immediately following chemotherapy with paclitaxel, suggesting a possible role of this agent in their pathogenesis.
Contrasts, counterfactuals,and causes
Authors: Grynaviski Eric
Published: February 2012

There is growing debate concerning the nature of causation in political science. In comparative politics and International Relations, scholars are divided by probabilistic, mechanistic, and conditions-based definitions of ‘cause.’ Moreover, post-positivist approaches to political science increasingly eschew causal analysis altogether. This article argues that the source of these divisions is methodological, not philosophical. Using the example of the Cuban missile crisis, a contrastive, counterfactual approach to causation, where a cause exists when the occurrence of one event rather than another leads to one event rather than another, meets the intuitions and the practice of political scientists engaged in different methodological approaches with different purposes. A contrastive, counterfactual account meets the intuitions of scholars engaged in quantitative and qualitative methods, and captures many of the intuitions guiding debates within qualitative and interpretive methods. By developing a common, unified approach to a key philosophical division, it is easier to identify the differences that matter.
Words about body and soul: Social representations relating to health and illness
Authors: Åsbring Pia
Published: February 2012

The purpose was to examine a sample of Stockholm residents’ social representations of their physical and mental health and ill-health. Four open-ended questions were answered by 1240 people between 18–80 years. A thematic analysis revealed nine aspects of health: physical, lifestyle, psychological, social, recreational, work and study, treatment, other and multifactorial aspects. Some cross-cutting themes were described to have an impact on health: empowerment, health-conscious lifestyle, life balance and life perspective. A key result is the interdependence between physical and mental health that was described by the respondents.
Evoking emotions and unpacking layered histories through young children’s illustrations of racial bus segregation
Authors: Kuby Candace R.
Published: February 2012

Drawing on theories of multi-modality and critical visual literacy, this article focuses on images that five-and six year-olds painted in a class-made book, Voice on the Bus, about racial segregation. The article discusses how children used illustrations to convey their understandings of Rosa Parks’ bus arrest in Alabama. A post-structural view focusing on images that five- and six year-olds painted in a class-made book, Voices on the Bus, about racial segregation, the article discusses how children used illustrations to convey their understanding of Rosa Parks’ bus arrest in Alabama. A post-structural (Kind, 2010) idea of art as an encounter, not as a fixed representation, shaped how the images were experienced for analysis. Using the notion of synaesthesia (the joining of senses), paintings were analysed for evoked emotions and blended sensations ( Berman, 1999 ; Boston, 2001 ). Additional analysis focused on sedimented meanings (Rowsell and Pahl, 2007), looking for traces from curricular conversations and local/global D/discourses about segregation, schooling experiences and religious undertones (Gee, 1996). The following analytical questions are discussed: In what ways does this illustration evoke a synaesthetic response? How is this image agentic? What are the sedimented meanings from the images? Insights gained are that children can create synaesthetic images to evoke emotions; educators can find traces of sedimented histories in student-made artefacts; and perhaps social action is embodied and expressed through art. Researchers are encouraged to continue using a hybrid of literacy theories and tools for multi-modal analysis.
The Changing Politics of Supreme Court Confirmations
Authors: Basinger Scott , Mak Maxwell
Published: February 2012

Senate voting on Supreme Court nominees offers a window into macro-political continuity and change. Clashes over confirmations once were reserved for a handful of exceptional cases, but recently have become the norm. Party cohesion in the Senate has also experienced a recent, rapid increase. An analysis of votes on 43 Supreme Court nominees reveals that senators polarize in response to rising levels of average party loyalty. The analysis further reveals that a senator who individually is more loyal to his or her party will be more likely to adopt an extreme position on confirmation, even after controlling for the effects of rising aggregate partisanship. Once the partisan trend is taken into account, our analysis contradicts the conventional wisdom that Robert Bork’s nomination instituted a “regime change” with a lasting effect on Senate voting patterns.
Use of Dietary Supplements for Cognitive Health
Authors: Laditka James N. , Laditka Sarah B. , Tait Elizabeth M. , Tsulukidze M. Maka
Published: February 2012

We studied use of vitamins, minerals, herbs, and other dietary supplements for cognitive health. We refer to these products as supplements. Data were from the 2007 National Health Interview Survey, which asked about complementary and alternative medicine (n = 22 783). Chi-square and multivariate logistic analyses were weighted for national representativeness, accounting for the survey design. Among supplement users, about 8.8% of those without cognitive problems used them for cognitive health; 15.7% of those with cognitive problems did so. Fish oil, Ginkgo biloba, and vitamins were commonly used for cognitive health. Among supplement users, 38% did not tell health care providers. In adjusted results, adults reporting cognitive problems were more likely than others to use supplements for cognitive health (odds ratio 1.77, confidence interval 1.39-2.25). Adults are more likely to use supplements to treat or cure cognitive problems than to prevent them. Many do not discuss this use with health care providers.
Modeling risk as a polyhedron
Authors: Gay Richard J , Hester Patrick T
Published: February 2012

Risk analysts historically have employed several approaches when examining the risk of terrorism to critical infrastructure. However, frequently these approaches rely on statistical methods, which suffer from a lack of appropriate historical data to produce distributions and do not integrate epistemic uncertainty. Other concerns include locating appropriate subject matter experts who can provide judgment and undertaking an associated validation of these judgments. Given the current body of knowledge, the modeling and simulation community can assist risk analysts to develop more robust methods for the analysis of the risk of terrorism in a critical infrastructure. This paper proposes that risk should be modeled and evaluated as a function of the volume of a risk polyhedron with the key characteristics of the risk of terrorism represented as nodes and the relationship between the key characteristics forming the edges. Specific attention is given to development of the threat component of the risk equation. The values of the key characteristics, instantiated as the length of the edges, are defaulted to absolute uncertainty, the state where there is no information for, or against, a particular causal factor. By adjusting an edge length, the polyhedron’s volume either increases or decreases, depending on the informed state of the modeler. Furthermore, individual threat scenarios can be joined, or nested, to inform risk understanding and management.
A review of second primary malignancy in patients with relapsed or refractory multiple myeloma treated with lenalidomide
Authors: Dimopoulos Meletios A. , Richardson Paul G. , Brandenburg Nancy , Yu Zhinuan , Weber Donna M. , Niesvizky Ruben , Morgan Gareth J.
Published: February 2012

In a retrospective pooled analysis of 11 clinical trials of lenalidomide-based therapy for relapsed/refractory multiple myeloma (MM; N = 3846), the overall incidence rate (IR, events per 100 patient-years) of second primary malignancies (SPMs) was 3.62. IR of invasive (hematologic and solid tumor) SPMs was 2.08, consistent with the background incidence of developing cancer. In a separate analysis of pooled data from pivotal phase 3 trials of relapsed or refractory MM (N = 703), the overall IR of SPMs was 3.98 (95% confidence interval [CI], 2.51-6.31) with lenalidomide/dexamethasone and 1.38 (95% CI, 0.44-4.27) with placebo/dexamethasone; IRs of nonmelanoma skin cancers were 2.40 (95% CI, 1.33-4.33) and 0.91 (95% CI, 0.23-3.66), respectively; IRs of invasive SPMs were 1.71 (95% CI, 0.86-3.43) and 0.91 (95% CI, 0.23-3.66), respectively. The risk of SPMs must be taken into account before initiating lenalidomide treatment. In the context of the observed survival benefit in relapsed or refractory MM patients, the benefit/risk profile of lenalidomide/dexamethasone remains positive.
N-cadherin in osteolineage cells is not required for maintenance of hematopoietic stem cells
Authors: Greenbaum Adam M. , Revollo Leila D. , Woloszynek Jill R. , Civitelli Roberto , Link Daniel C.
Published: February 2012

There is evidence suggesting that N-cadherin expression on osteoblast lineage cells regulates hematopoietic stem cell (HSC) function and quiescence. To test this hypothesis, we conditionally deleted N-cadherin (Cdh2) in osteoblasts using Cdh2flox/flox Osx-Cre mice. N-cadherin expression was efficiently ablated in osteoblast lineage cells as assessed by mRNA expression and immunostaining of bone sections. Basal hematopoiesis is normal in these mice. In particular, HSC number, cell cycle status, long-term repopulating activity, and self-renewal capacity were normal. Moreover, engraftment of wild-type cells into N-cadherin–deleted recipients was normal. Finally, these mice responded normally to G-CSF, a stimulus that mobilizes HSCs by inducing alterations to the stromal micro-environment. In conclusion, N-cadherin expression in osteoblast lineage cells is dispensable for HSC maintenance in mice.
Exposure to second-hand smoke and reproductive outcomes depending on maternal asthma
Authors: Sunyer Jordi , Garcia-Esteban Raquel , Castilla Ane Miren , Aurrekoetxea Juan José , Iñiguez Carmen , Tardón Adonina , Espada Mercedes , Lertxundi Aitana , Chatzi Leda , Rebagliato Marisa , Kogevinas Manolis
Published: February 2012

Tobacco consumption and exposure to second-hand smoke (SHS) are associated with reduced birth weight. One issue that has not been clarified previously is that of the potential higher risk of this outcome in mothers with asthma. We assessed the role of prenatal maternal tobacco use and SHS on reproductive outcomes and assessed the interaction with maternal history of asthma.

Data was collected from the INMA study, a maternal birth cohort selected from the general population established in Spain in 2002. We measured cotinine at the 32nd week of pregnancy in 2,219 females. Diagnosed maternal asthma was self-reported during pregnancy.

35% of mothers reported not being exposed to smoking or SHS during pregnancy. Active smoking (i.e.self-reported or cotinine >50 ng·mL−1) was related to a 134 g decrease in birth weight and a relative risk of 1.8 for small for gestational age and fetal growth restriction. These results were not modified by maternal asthma. Maternal asthma had a similar frequency in all exposure groups. Non SHS-exposed females had the lowest prevalence of asthma. SHS (i.e.cotinine 20–50 ng·mL−1) decreased birth weight by 32 g among those without maternal asthma, but these differences were not statistically significant (95% CI -88.76–24.76). Maternal asthma did not promote these effects.

Maternal history of asthma did not modify the effects of smoking on reproductive outcomes in a cohort sampled from the general population.
Safety and efficacy of exercise training in various forms of pulmonary hypertension
Authors: Grünig Ekkehard , Lichtblau Mona , Ehlken Nicola , Ghofrani Hossein A. , Reichenberger Frank , Staehler Gerd , Halank Michael , Fischer Christine , Seyfarth Hans-Jürgen , Klose Hans , Meyer Andreas , Sorichter Stephan , Wilkens Heinrike , Rosenkranz Stephan , Opitz Christian , Leuchte Hanno , Karger Gabriele , Speich Rudolf , Nagel Christian
Published: February 2012

The objective of this prospective study was to assess safety and efficacy of exercise training in a large cohort of patients with different forms and World Health Organization (WHO) functional classes of chronic pulmonary hypertension (PH).

183 patients with PH (pulmonary arterial hypertension (PAH), chronic thromboembolic PH and PH due to respiratory or left heart diseases received exercise training in hospital for 3 weeks and continued at home. Adverse events have been monitored during the in-hospital training programme. Efficacy parameters were evaluated at baseline, and after 3 and 15 weeks.

After 3 and 15 weeks, patients significantly improved the distance walked in 6 min (6MWD) compared to baseline, scores of quality of life, WHO functional class, peak oxygen consumption, oxygen pulse, heart rate and systolic pulmonary artery pressure at rest and maximal workload. The improvement in 6MWD was similar in patients with different PH forms and functional classes. Even in severely affected patients (WHO functional class IV), exercise training was highly effective. Adverse events, such as respiratory infections, syncope or presyncope, occurred in 13% of patients.

Exercise training in PH is an effective but not a completely harmless add-on therapy, even in severely diseased patients, and should be closely monitored.
Computed tomography-quantified emphysema distribution is associated with lung function decline
Authors: Mohamed Hoesein Firdaus A.A. , van Rikxoort Eva , van Ginneken Bram , de Jong Pim A. , Prokop Mathias , Lammers Jan-Willem J. , Zanen Pieter
Published: February 2012

Emphysema distribution is associated with chronic obstructive pulmonary disease. It is, however, unknown whether computed tomography (CT)-quantified emphysema distribution (upper/lower lobe) is associated with lung function decline in heavy (former) smokers.

587 male participants underwent lung CT and pulmonary function testing at baseline and after a median (interquartile range) follow-up of 2.9 (2.8–3.0) yrs. The lungs were automatically segmented based on anatomically defined lung lobes. Severity of emphysema was automatically quantified per anatomical lung lobe and was expressed as the 15th percentile (Hounsfield unit point below which 15% of the low-attenuation voxels are distributed (Perc15)). The CT-quantified emphysema distribution was based on principal component analysis. Linear mixed models were used to assess the association of emphysema distribution with forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC), FEV1and FVC decline.

Mean±sdage was 60.2±5.4 yrs, mean baseline FEV1/FVC was 71.6±9.0% and overall mean Perc15 was -908.5±20.9 HU. Participants with upper lobe-predominant CT-quantified emphysema had a lower FEV1/FVC, FEV1and FVC after follow-up compared with participants with lower lobe-predominant CT-quantified emphysema (p=0.001), independent of the total extent of CT-quantified emphysema.

Heavy (former) smokers with upper lobe-predominant CT-quantified emphysema have a more rapid decrease in lung function than those with lower lobe-predominant CT-quantified emphysema.
Transmissible strains ofPseudomonas aeruginosain cystic fibrosis lung infections
Authors: Fothergill Joanne L. , Walshaw Martin J. , Winstanley Craig
Published: February 2012

Pseudomonas aeruginosachronic lung infections are the major cause of morbidity and mortality associated with cystic fibrosis. For many years, the consensus was that cystic fibrosis patients acquireP. aeruginosafrom the environment, and hence harbour their own individual clones. However, in the past 15 yrs the emergence of transmissible strains, in some cases associated with greater morbidity and increased antimicrobial resistance, has changed the way that many clinics treat their patients. Here we provide a summary of reported transmissible strains in the UK, other parts of Europe, Australia and North America. In particular, we discuss the prevalence, epidemiology, unusual genotypic and phenotypic features, and virulence of the most intensively studied transmissible strain, the Liverpool epidemic strain. We also discuss the clinical impact of transmissible strains, in particular the diagnostic and infection control approaches adopted to counter their spread. Genomic analysis carried out so far has provided little evidence that transmissibility is due to shared genetic characteristics between different strains. Previous experiences with transmissible strains should help us to learn lessons for the future. In particular, there is a clear need for strain surveillance if emerging problem strains are to be detected before they are widely transmitted.
Transcriptome profiling of low temperature-treated cassava apical shoots showed dynamic responses of tropical plant to cold stress
Authors: An Dong , Yang Jun , Zhang Peng
Published: February 2012

Background

Cassava is an important tropical root crop adapted to a wide range of environmental stimuli such as drought and acid soils. Nevertheless, it is an extremely cold-sensitive tropical species. Thus far, there is limited information about gene regulation and signalling pathways related to the cold stress response in cassava. The development of microarray technology has accelerated the study of global transcription profiling under certain conditions.

Results

A 60-mer oligonucleotide microarray representing 20,840 genes was used to perform transcriptome profiling in apical shoots of cassava subjected to cold at 7°C for 0, 4 and 9 h. A total of 508 transcripts were identified as early cold-responsive genes in which 319 sequences had functional descriptions when aligned with Arabidopsis proteins. Gene ontology annotation analysis identified many cold-relevant categories, including 'Response to abiotic and biotic stimulus', 'Response to stress', 'Transcription factor activity', and 'Chloroplast'. Various stress-associated genes with a wide range of biological functions were found, such as signal transduction components (e.g., MAP kinase 4), transcription factors (TFs, e.g., RAP2.11), and reactive oxygen species (ROS) scavenging enzymes (e.g., catalase 2), as well as photosynthesis-related genes (e.g., PsaL). Seventeen major TF families including many well-studied members (e.g., AP2-EREBP) were also involved in the early response to cold stress. Meanwhile, KEGG pathway analysis uncovered many important pathways, such as 'Plant hormone signal transduction' and 'Starch and sucrose metabolism'. Furthermore, the expression changes of 32 genes under cold and other abiotic stress conditions were validated by real-time RT-PCR. Importantly, most of the tested stress-responsive genes were primarily expressed in mature leaves, stem cambia, and fibrous roots rather than apical buds and young leaves. As a response to cold stress in cassava, an increase in transcripts and enzyme activities of ROS scavenging genes and the accumulation of total soluble sugars (including sucrose and glucose) were also detected.

Conclusions

The dynamic expression changes reflect the integrative controlling and transcriptome regulation of the networks in the cold stress response of cassava. The biological processes involved in the signal perception and physiological response might shed light on the molecular mechanisms related to cold tolerance in tropical plants and provide useful candidate genes for genetic improvement.
Non-hispanic whites have higher risk for pulmonary impairment from pulmonary tuberculosis
Authors: Pasipanodya Jotam G , Vecino Edgar , Miller Thaddeus L , Munguia Guadalupe , Drewyer Gerry , Fernandez Michel , Slocum Philip , Weis Stephen E
Published: February 2012

Background

Disparities in outcomes associated with race and ethnicity are well documented for many diseases and patient populations. Tuberculosis (TB) disproportionately affects economically disadvantaged, racial and ethnic minority populations. Pulmonary impairment after tuberculosis (PIAT) contributes heavily to the societal burden of TB. Individual impacts associated with PIAT may vary by race/ethnicity or socioeconomic status.

Methods

We analyzed the pulmonary function of 320 prospectively identified patients with pulmonary tuberculosis who had completed at least 20 weeks standard anti-TB regimes by directly observed therapy. We compared frequency and severity of spirometry-defined PIAT in groups stratified by demographics, pulmonary risk factors, and race/ethnicity, and examined clinical correlates to pulmonary function deficits.

Results

Pulmonary impairment after tuberculosis was identified in 71% of non-Hispanic Whites, 58% of non-Hispanic Blacks, 49% of Asians and 32% of Hispanics (p < 0.001). Predictors for PIAT varied between race/ethnicity. PIAT was evenly distributed across all levels of socioeconomic status suggesting that PIAT and socioeconomic status are not related. PIAT and its severity were significantly associated with abnormal chest x-ray, p < 0.0001. There was no association between race/ethnicity and time to beginning TB treatment, p = 0.978.

Conclusions

Despite controlling for cigarette smoking, socioeconomic status and time to beginning TB treatment, non-Hispanic White race/ethnicity remained an independent predictor for disproportionately frequent and severe pulmonary impairment after tuberculosis relative to other race/ethnic groups. Since race/ethnicity was self reported and that race is not a biological construct: these findings must be interpreted with caution. However, because race/ethnicity is a proxy for several other unmeasured host, pathogen or environment factors that may contribute to disparate health outcomes, these results are meant to suggest hypotheses for further research.
Using CF11 cellulose columns to inexpensively and effectively remove human DNA from Plasmodium falciparum-infected whole blood samples
Authors: Venkatesan Meera , Amaratunga Chanaki , Campino Susana , Auburn Sarah , Koch Oliver , Lim Pharath , Uk Sambunny , Socheat Duong , Kwiatkowski Dominic P , Fairhurst Rick M , Plowe Christopher V
Published: February 2012

Background

Genome and transcriptome studies of Plasmodium nucleic acids obtained from parasitized whole blood are greatly improved by depletion of human DNA or enrichment of parasite DNA prior to next-generation sequencing and microarray hybridization. The most effective method currently used is a two-step procedure to deplete leukocytes: centrifugation using density gradient media followed by filtration through expensive, commercially available columns. This method is not easily implemented in field studies that collect hundreds of samples and simultaneously process samples for multiple laboratory analyses. Inexpensive syringes, hand-packed with CF11 cellulose powder, were recently shown to improve ex vivo cultivation of Plasmodium vivax obtained from parasitized whole blood. This study was undertaken to determine whether CF11 columns could be adapted to isolate Plasmodium falciparum DNA from parasitized whole blood and achieve current quantity and purity requirements for Illumina sequencing.

Methods

The CF11 procedure was compared with the current two-step standard of leukocyte depletion using parasitized red blood cells cultured in vitro and parasitized blood obtained ex vivo from Cambodian patients with malaria. Procedural variations in centrifugation and column size were tested, along with a range of blood volumes and parasite densities.

Results

CF11 filtration reliably produces 500 nanograms of DNA with less than 50% human DNA contamination, which is comparable to that obtained by the two-step method and falls within the current quality control requirements for Illumina sequencing. In addition, a centrifuge-free version of the CF11 filtration method to isolate P. falciparum DNA at remote and minimally equipped field sites in malaria-endemic areas was validated.

Conclusions

CF11 filtration is a cost-effective, scalable, one-step approach to remove human DNA from P. falciparum-infected whole blood samples.
An improved single-step lysis protocol to measure luciferase bioluminescence in Plasmodium falciparum
Authors: Hasenkamp Sandra , Wong Eleanor H , Horrocks Paul
Published: February 2012

This report describes the optimization and evaluation of a simple single-step lysis protocol to measure luciferase bioluminescence from genetically modified Plasmodium falciparum. This protocol utilizes a modified commercial buffer to improve speed of assay and consistency in the bioluminescence signal measured by reducing the manipulation steps required to release the cytoplasmic fraction. The utility of this improved assay protocol is demonstrated in typical assays that explore absolute and temporal gene expression activity.
Isolated displaced non-union of a triquetral body fracture: a case report
Authors: Rasoli Sonia , Ricks Matthew , Packer Greg
Published: February 2012

Introduction

Fractures of the body of the triquetral bone are the second most common carpal fractures, and these fractures can be missed on plain X-ray. Although non-union of triquetral body fractures is very rare, such cases are associated with considerable morbidity and reduction in functional activity.

Case presentation

We report the case of a 29-year-old Caucasian British man who sustained an isolated displaced triquetral body fracture that resulted in non-union, who was treated surgically. We describe an original operative management for this debilitating injury. An open reduction and internal fixation using double headed compression screws was performed, without bone grafting, and with early immobilization of the wrist.

Conclusions

We propose this novel approach and advocate early clinical suspicion of triquetral body fractures in patients with a history of fall on an outstretched hand and ulnar sided wrist pain. We recommend evaluation using computed tomography or magnetic resonance imaging scanning.
Differential regulation of intracellular factors mediating cell cycle, DNA repair and inflammation following exposure to silver nanoparticles in human cells
Authors: AshaRani PV , Sethu Swaminathan , Lim Hui Kheng , Balaji Ganapathy , Valiyaveettil Suresh , Hande M Prakash
Published: February 2012

Background

Investigating the cellular and molecular signatures in eukaryotic cells following exposure to nanoparticles will further our understanding on the mechanisms mediating nanoparticle induced effects. This study illustrates the molecular effects of silver nanoparticles (Ag-np) in normal human lung cells, IMR-90 and human brain cancer cells, U251 with emphasis on gene expression, induction of inflammatory mediators and the interaction of Ag-np with cytosolic proteins.

Results

We report that silver nanoparticles are capable of adsorbing cytosolic proteins on their surface that may influence the function of intracellular factors. Gene and protein expression profiles of Ag-np exposed cells revealed up regulation of many DNA damage response genes such as Gadd 45 in both the cell types and ATR in cancer cells. Moreover, down regulation of genes necessary for cell cycle progression (cyclin B and cyclin E) and DNA damage response/repair (XRCC1 and 3, FEN1, RAD51C, RPA1) was observed in both the cell lines. Double strand DNA damage was observed in a dose dependant manner as evidenced in γH2AX foci assay. There was a down regulation of p53 and PCNA in treated cells. Cancer cells in particular showed a concentration dependant increase in phosphorylated p53 accompanied by the cleavage of caspase 3 and PARP. Our results demonstrate the involvement of NFκB and MAP kinase pathway in response to Ag-np exposure. Up regulation of pro-inflammatory cytokines such as interleukins (IL-8, IL-6), macrophage colony stimulating factor, macrophage inflammatory protein in fibroblasts following Ag-np exposure were also observed.

Conclusion

In summary, Ag-np can modulate gene expression and protein functions in IMR-90 cells and U251 cells, leading to defective DNA repair, proliferation arrest and inflammatory response. The observed changes could also be due to its capability to adsorb cytosolic proteins on its surface.
Evidence summaries: the evolution of a rapid review approach
Authors: Khangura Sara , Konnyu Kristin , Cushman Rob , Grimshaw Jeremy , Moher David
Published: February 2012

Background

Rapid reviews have emerged as a streamlined approach to synthesizing evidence - typically for informing emergent decisions faced by decision makers in health care settings. Although there is growing use of rapid review 'methods', and proliferation of rapid review products, there is a dearth of published literature on rapid review methodology. This paper outlines our experience with rapidly producing, publishing and disseminating evidence summaries in the context of our Knowledge to Action (KTA) research program.

Methods

The KTA research program is a two-year project designed to develop and assess the impact of a regional knowledge infrastructure that supports evidence-informed decision making by regional managers and stakeholders. As part of this program, we have developed evidence summaries - our form of rapid review - which have come to be a flagship component of this project. Our eight-step approach for producing evidence summaries has been developed iteratively, based on evidence (where available), experience and knowledge user feedback. The aim of our evidence summary approach is to deliver quality evidence that is both timely and user-friendly.

Results

From November 2009 to March 2011 we have produced 11 evidence summaries on a diverse range of questions identified by our knowledge users. Topic areas have included questions of clinical effectiveness to questions on health systems and/or health services. Knowledge users have reported evidence summaries to be of high value in informing their decisions and initiatives. We continue to experiment with incorporating more of the established methods of systematic reviews, while maintaining our capacity to deliver a final product in a timely manner.

Conclusions

The evolution of the KTA rapid review evidence summaries has been a positive one. We have developed an approach that appears to be addressing a need by knowledge users for timely, user-friendly, and trustworthy evidence and have transparently reported these methods here for the wider rapid review and scientific community.
Tannic Acid Down-Regulates the Angiotensin Type 1 Receptor Through a MAPK-Dependent Mechanism
Authors: Yesudas Rekha , Gumaste Upendra , Snyder Russell , Thekkumkara Thomas
Published: February 2012

In the present study, we investigated the effects of tannic acid (TA), a hydrolysable polyphenol, on angiotensin type 1 receptor (AT1R) expression in continuously passaged rat liver epithelial cells. Under normal conditions, exposure of cells to TA resulted in the down-regulation of AT1R-specific binding in concentrations ranging from 12.5–100 μg/ml (7.34–58.78 μm) over a time period of 2–24 h with no change in receptor affinity to angiotensin II (AngII). The inhibitory effect of TA on AT1R was specific and reversible. In TA-treated cells, we observed a significant reduction in AngII-mediated intracellular calcium signaling, a finding consistent with receptor down-regulation. Under similar conditions, TA down-regulated AT1R mRNA expression without changing the rate of mRNA degradation, suggesting that TA's effect is mediated through transcriptional inhibition. Cells expressing recombinant AT1R without the native promoter show no change in receptor expression, whereas a pCAT reporter construct possessing the rat AT1R promoter was significantly reduced in activity. Furthermore, TA induced the phosphorylation of MAPK p42/p44. Pretreatment of the cells with a MAPK kinase (MEK)-specific inhibitor PD98059 prevented TA-induced MAPK phosphorylation and down-regulation of the AT1R. Moreover, there was no reduction in AngII-mediated intracellular calcium release upon MEK inhibition, suggesting that TA's observed inhibitory effect is mediated through MEK/MAPK signaling. Our findings demonstrate, for the first time, that TA inhibits AT1R gene expression and cellular response, suggesting the observed protective effects of dietary polyphenols on cardiovascular conditions may be, in part, through inhibition of AT1R expression.