bluuebunny/crossref_metadata_2025 huggingface dataset:
Two thymidine kinases and one multisubstrate deoxyribonucleoside kinase salvage DNA precursors in Arabidopsis thaliana
Authors: Clausen Anders R. , Girandon Lenart , Ali Ashfaq , Knecht Wolfgang , Rozpedowska Elzbieta , Sandrini Michael P. B. , Andreasson Erik , Munch‐Petersen Birgitte , Piškur Jure
Published: August 2012

Deoxyribonucleotides are the building blocks of DNA and can be synthesized via de novo and salvage pathways. Deoxyribonucleoside kinases (EC 2.7.1.145) salvage deoxyribonucleosides by transfer of a phosphate group to the 5′ of a deoxyribonucleoside. This salvage pathway is well characterized in mammals, but in contrast, little is known about how plants salvage deoxyribonucleosides. We show that during salvage, deoxyribonucleosides can be phosphorylated by extracts of Arabidopsis thaliana into corresponding monophosphate compounds with an unexpected preference for purines over pyrimidines. Deoxyribonucleoside kinase activities were present in all tissues during all growth stages. In the A. thaliana genome, we identified two types of genes that could encode enzymes which are involved in the salvage of deoxyribonucleosides. Thymidine kinase activity was encoded by two thymidine kinase 1 (EC 2.7.1.21)‐like genes (AtTK1a and AtTK1b). Deoxyadenosine, deoxyguanosine and deoxycytidine kinase activities were encoded by a single AtdNK gene. T‐DNA insertion lines of AtTK1a and AtTK1b mutant genes had normal growth, although AtTK1a AtTK1b double mutants died at an early stage, which indicates that AtTK1a and AtTK1b catalyze redundant reactions. The results obtained in the present study suggest a crucial role for the salvage of thymidine during early plant development.

Database

Sequence data from the present study have been deposited in the EMBL database/GenBank under accession numbers: AT3G07800.1 (AtTK1a), At5G23070.1 (AtTK1b) and AT1G72040.1 (AtdNK).
Serum NT‐proBNP in the early detection of doxorubicin‐induced cardiac dysfunction
Authors: Kittiwarawut Annop , Vorasettakarnkij Yongkasem , Tanasanvimon Suebpong , Manasnayakorn Sopark , Sriuranpong Virote
Published: August 2012

Aim

Cardiac dysfunction is a major limitation of anthracycline treatment in cancer patients. There are several useful serum markers in other types of cardiomyopathy, including N‐terminal pro‐brain‐natriuretic peptide (NT‐proBNP), troponin‐T and creatine kinase MB isoform. We investigated the potential application of these serum biomarkers in cancer patients receiving treatment with anthracycline.

Methods

We collected data from 52 female breast cancer patients receiving doxorubicin and cyclophosphamide every 3 weeks for four cycles. Cardiac function evaluations by echocardiography were done at baseline and at the end of the fourth cycle of chemotherapy. Patients’ blood samples were serially measured for cardiac biomarkers.

Results

The mean cumulative dose of doxorubicin in this study was 237 mg/m2. No symptomatic heart failure was detected during the study period. However, there were significant asymptomatic reductions of left ventricular ejection fraction (LVEF) from mean ± SD 70.7 ± 6% at baseline to 67.0 ± 5% (P < 0.001). By clinical toxicity criteria the LVEF decline was grade I in 18% and grade II in 4%. After one dose of chemotherapy, a significant rise of serum NT‐proBNP occurred in patients who subsequently developed an LVEF reduction compared with patients with normal LVEF (P = 0.04). A correlation analysis demonstrated that the reduction of fractional shortening was significantly associated with elevated NT‐proBNP (r = −0.016, P = 0.014).

Conclusion

Asymptomatic reductions in cardiac function are common in breast cancer patients treated with doxorubicin. NT‐proBNP may serve as a convenient serum biomarker for the early detection of cardiotoxicity induced by anthracycline.
Patient comprehension of discharge instructions from the emergency department: A literature review
Authors: Alberti Traci L. , Nannini Angela
Published: August 2012

Purpose

To examine research published from 1995 to 2010, evaluating patient comprehension of discharge instructions from emergency department (ED) or urgent care (UC) settings. Specifically, we examined: (a) the interventions utilized to provide discharge instructions, (b) the methods used to assess patient comprehension, and (c) the most effective strategies for assuring patient comprehension of ED discharge instructions.

Data sources

A comprehensive literature review was conducted utilizing the following databases: Cumulative Index to Nursing and Allied Health Literature (CINAHL), Health Reference Center Academic, Medline, Cochrane, and Ovid. English language peer‐reviewed articles published between 1995 and 2010 were reviewed. Search terms included patient, comprehension, understanding, discharge instructions, health education, and emergency medicine.

Conclusions

Increases in patient comprehension of ED discharge instructions are identified with alternative teaching interventions (multimedia) in comparison to traditional standardized written discharge instructions (usual care). Literature suggests clinicians seldom clarify patient comprehension in practice, though effective methods are noted in research. Future research is needed to explore innovative teaching interventions and their impact upon patient comprehension and patient outcomes.

Implications for practice

To ensure patient comprehension of discharge instructions, the simplification of discharge material is paramount. Nurse practitioners working in ED or UC settings can improve upon “usual care” by exploring more innovative teaching interventions.
Exchange Rate Choices of Microstates
Authors: Imam Patrick
Published: August 2012

In this paper I first explain why most microstates (countries with less than two million inhabitants) have gained independence only in the last 30 years. Despite the higher costs and risks microstates face, their ability to better accommodate local preferences, combined with a more integrated world economy, probably explains why there are now more benefits to independence. I explain why microstates at independence have chosen either dollarization, currency board arrangements, or fixed exchange rates rather than more flexible forms of exchange rate systems. I then, using the Geweke‐Hajivassiliou‐Keane multivariate normal simulator, model empirically the determinants of each of the different fixed exchange rate regimes in microstates and analyze the policy implications.
Trade Integration with the European Union: Poverty Impacts in Ecuador
Authors: Wong Sara , Kulmer Veronika
Published: August 2012

The government of Ecuador is seeking to negotiate a trade agreement with the European Union (EU). This study examines the impacts of such a trade agreement on rural and urban poverty in Ecuador by combining a household income and occupational choice model with a computable general equilibrium model. The results suggest that a trade agreement with the EU may have a significant impact on poverty. However, the nature and extent of the impact varies depending on the degree of initial tariff reduction, labor market considerations, and whether Ecuadorian bananas are granted better access to the EU market.
Analyses and assessment of the spatial and temporal distribution of nitrogen compounds in surface waters
Authors: Georgieva Nedyalka , Yaneva Zvezdelina , Kostadinova Gergana
Published: August 2012

The temporal concentration variations and spatial distribution of nitrogen compounds (nitrate, nitrite, ammonium) in the natural surface waters of Stara Zagora Region, Bulgaria, over a period of 1 year were assessed in the present study. Nitrate‐nitrogen concentrations in all surface water samples, except for the December value – 21.8 mg/L in Zetyovo Reservoir, were within the permissible national quality standards. NO2
–‐N could be classified as a priority pollutant of Chirpan and Zetyovo Reservoirs waters. The greatest extent of NH
4
+‐N pollution was registered in Chirpan Reservoir surface waters. The correlation study revealed appreciable mutual relationship only between NH4
+‐N and NO
2
–‐N in the surface waters. The hierarchical cluster analysis (HCA) exhibited divergent apportionment of nitrogen compounds in the surface water bodies.
Application of surrogate artificial intelligent models for real‐time flood routing
Authors: Ghalkhani Hossein , Golian Saeed , Saghafian Bahram , Farokhnia Ashkan , Shamseldin Asaad
Published: August 2012

Developing a robust flood forecasting and warning system (FFWS) is essential in flood‐prone areas. Hydrodynamic models, which are a major part of such systems, usually suffer from computational instabilities and long runtime problems, which are particularly important in real‐time applications. In this study, two artificial intelligence models, namely artificial neural network (ANN) and adaptive neuro‐fuzzy inference system (ANFIS), were used for flood routing in an FFWS in Madarsoo river basin, Iran. For this purpose, different rainfall patterns were transformed to run‐off hydrographs using the Hydrologic Engineering Center (HEC)‐1 hydrological model and routed along the river using HEC river analysis system RAS hydrodynamic model. Then, the simulated hydrographs with different lag times were used as inputs for training of ANN and ANFIS models to simulate flood hydrograph at the basin outlet. Results showed that the simulations obtained from ANN and ANFIS coincided with the results simulated by the HEC‐RAS, and application of such models is strongly suggested as a backup tool for flood routing in FFWSs.
Feminism and Religion: Intersections between Western Activism, Theology and Theory
Authors: Zwissler Laurel
Published: August 2012

What is the relationship of religion in general, or of specific religions, to misogyny and the oppression of women? This article discusses Western feminism and religion, with a focus on North America, examining: 1) the relationship of religion to feminism as a political movement; 2) the role of feminism in religion, especially Western traditions; and 3) contributions of feminist criticism to the academic study of religion. The relationship between feminism and religion is multifaceted. Religion is important in feminist political activism, throughout first, second and third waves. Feminist activism is mutually influential to feminist theory, which approaches questions about gender not as optional, but as imperative to any rigorous analytic perspective. Feminist criticism of religion includes both feminist theology, which focuses on reforming religious traditions to be more egalitarian, and feminist scholarship in the academic study of religion, which challenges scholars to re‐evaluate dominant models, such as the category of religion itself.
Disability Theology
Authors: Creamer Deborah Beth
Published: August 2012

Disability theology explores the ways in which religious traditions have engaged (or failed to engage) notions of disability and impairment, and offers constructive possibilities for inclusive theological work in the future. This essay reviews four primary models of disability (moral model, medical model, social model, and limits model) and explores how these relate to religious understandings and practices. The image of the Disabled God is highlighted, as are the ways this field has come to engage varieties of disability experience (including cognitive disabilities and autism) and diversity more broadly. Philosophical notions (such as those around normalcy or human flourishing) are explored alongside advocacy and access issues (particularly with regard to religious practices such as preaching, religious education, and biblical interpretation). Future possibilities and directions for disability theology are also proposed.
Influenza surveillance in Europe: establishing epidemic thresholds by the Moving Epidemic Method
Authors: Vega Tomás , Lozano Jose Eugenio , Meerhoff Tamara , Snacken René , Mott Joshua , Ortiz de Lejarazu Raul , Nunes Baltazar
Published: August 2012

Please cite this paper as:Vegaet al.(2012) Influenza surveillance in Europe: establishing epidemic thresholds by the moving epidemic method. Influenza and Other Respiratory Viruses 7(4), 546–558.

Background Timely influenza surveillance is important to monitor influenza epidemics.

Objectives (i) To calculate the epidemic threshold for influenza‐like illness (ILI) and acute respiratory infections (ARI) in 19 countries, as well as the thresholds for different levels of intensity. (ii) To evaluate the performance of these thresholds.

Methods The moving epidemic method (MEM) has been developed to determine the baseline influenza activity and an epidemic threshold. False alerts, detection lags and timeliness of the detection of epidemics were calculated. The performance was evaluated using a cross‐validation procedure.

Results The overall sensitivity of the MEM threshold was 71·8% and the specificity was 95·5%. The median of the timeliness was 1 week (range: 0–4·5).

Conclusions The method produced a robust and specific signal to detect influenza epidemics. The good balance between the sensitivity and specificity of the epidemic threshold to detect seasonal epidemics and avoid false alerts has advantages for public health purposes. This method may serve as standard to define the start of the annual influenza epidemic in countries in Europe.
Long‐term vaccine‐induced heterologous protection against H5N1 influenza viruses in the ferret model
Authors: Ducatez Mariette F. , Webb Ashley , Crumpton Jeri‐Carol , Webby Richard J.
Published: August 2012

Please cite this paper as: Ducatez et al. (2012) Long‐term vaccine‐induced heterologous protection against H5N1 influenza viruses in the ferret model. Influenza and Other Respiratory Viruses 7(4), 506–512.

Background  Highly pathogenic H5N1 influenza viruses reemerged in humans in 2003 and have caused fatal human infections in Asia and Africa as well as ongoing outbreaks in poultry. These viruses have evolved substantially and are now so antigenically varied that a single vaccine antigen may not protect against all circulating strains. Nevertheless, studies have shown that substantial cross‐reactivity can be achieved with H5N1 vaccines. These studies have not, however, addressed the issue of duration of such cross‐reactive protection.

Objectives  To directly address this using the ferret model, we used two recommended World Health Organization H5N1 vaccine seed strains – A/Vietnam/1203/04 (clade 1) and A/duck/Hunan/795/02 (clade 2.1) – seven single, double, or triple mutant viruses based on A/Vietnam/1203/04, and the ancestral viruses A and D, selected from sequences at nodes of the hemagglutinin and neuraminidase gene phylogenies to represent antigenically diverse progeny H5N1 subclades as vaccine antigens.

Results  All inactivated whole‐virus vaccines provided full protection against morbidity and mortality in ferrets challenged with the highly pathogenic H5N1 strain A/Vietnam/1203/04 5 months and 1 year after immunization.

Conclusion  If an H5N1 pandemic was to arise, and with the hypothesis that one can extrapolate the results from three doses of a whole‐virion vaccine in ferrets to the available split vaccines for use in humans, the population could be efficiently immunized with currently available H5N1 vaccines, while the homologous vaccine is under production.
Vascular Degeneration in Parkinson's Disease
Authors: Guan Jian , Pavlovic Darja , Dalkie Nicholas , Waldvogel Henry J. , O'Carroll Simon J. , Green Colin R. , Nicholson Louise F.B.
Published: August 2012

Vascular degeneration plays a significant role in contributing to neurodegenerative conditions such as Alzheimer's disease. Our understanding of the vascular components in Parkinson's disease (PD) is however limited. We have examined the vascular morphology of human brain tissue from both PD and the control cases using immunohistochemical staining and image analysis. The degenerative morphology seen in PD cases included the formation of endothelial cell “clusters,” which may be contributed by the fragmentation of capillaries. When compared to the control cases, the capillaries of PDs were less in number (P < 0.001), shorter in length (P < 0.001) and larger in diameter (P < 0.01) with obvious damage to the capillary network evidenced by less branching (P < 0.001). The level of degeneration seen in the caudate nucleus was also seen in the age‐matched control cases. Vessel degeneration associated with PD was, however, found in multiple brain regions, but particularly in the substantia nigra, middle frontal cortex and brain stem nuclei. The data suggest that vascular degeneration could be an additional contributing factor to the progression of PD. Thus, treatments that prevent vascular degeneration and improve vascular remodeling may be a novel target for the treatment of PD.
Season's Variation Impact on Citrus aurantium Leaves Essential Oil: Chemical Composition and Biological Activities
Authors: Ellouze Inès , Abderrabba Manef , Sabaou Nassereddine , Mathieu Florence , Lebrihi Ahmed , Bouajila Jalloul
Published: August 2012

Abstract:  Citrus aurantium leaves' essential oils (EOs) were evaluated for chemical composition and antioxidant and antibacterial activities. The vegetable material, taken 5 times during the year, has undergone the hydrodistillation to prepare EO. Chemical characterization by gas chromatography/mass spectrometry and GC/flame ionization detection allowed the identification of 46 compounds, and a notable quantitative and qualitative differences between the different Petitgrain samples according to the harvest time. Linalool (43.2% to 65.97%), linalyl acetate (0.77% to 24.77%), and α‐terpineol (9.29% to 12.12%) were the main components. The most important number of components was registered for summer EOs (July and September). The 5 EOs submitted biological activities screening, namely, antioxidant and antimicrobial activities. Weak antioxidant activities (IC50 values >10000 mg/L) were registered by both 1,1‐diphenyl‐2‐picrylhydrazyl and 2,2′‐azinobis‐3‐ethylbenzothiazoline‐6‐sulphonate assays, mostly because the weak amount of phenols in EOs. Antibacterial activities (12 microorganisms) were registered against Gram‐positive bacteria [Bacillus subtilis (MIC = 2.7 mg/mL), Staphylococcus aureus (4.8 mg/mL)], and moderated ones against yeasts [Saccharomyces cerevisiae (9.2 mg/mL)] and fungi [Mucor ramannianus (5 mg/mL)]. Positive correlations between the identified compounds and the antimicrobial activities were noted. Many compounds were correlated to antimicrobial activity mainly caryophyllene oxide against Escherichia coli (R2= 0.99), S. cerevisiae (R2= 0.99), and Fusarium culmorum (R2= 0.99).
Potential Chemical Markers for the Identification of Irradiated Sausages
Authors: Kwon Joong Ho , Akram Kashif , Nam Ki Chang , Min Byungrok , Lee Eun Joo , Ahn Dong U.
Published: August 2012

Abstract:  Hydrocarbons, gas compounds, and off‐odor volatiles were determined for irradiated (0 or 5 kGy) commercial sausages with different fat contents (16% and 29%) during a 60‐d storage period at 4 °C. Total of 4 hydrocarbons (C14:1, C15:0, C16:2, and C17:1) were detected only in irradiated sausages: the amount of C16:2 was the highest, followed by C17:1, C14:1, and C15:0. The concentrations of hydrocarbons decreased significantly (P < 0.05) with storage, but were still detectable at the end of 60‐d storage. Irradiated sausages produced significantly higher amounts of CO than the nonirradiated ones. CH4 was detected only in irradiated sausages. Dimethyl disulfide was detected only in irradiated sausages and its concentration decreased significantly (P < 0.05) with storage. Fat content of sausages showed a significant effect on the production and retention of hydrocarbons, gas compounds, and sulfur volatiles in irradiated sausages during storage. Some hydrocarbons (C16:2, C17:1, C14:1, and C15:0), CH4, and dimethyl disulfide were only found in irradiated sausages indicating that these compounds can be used as potential markers for irradiated sausages.
Incentive Motivation, Cognitive Control, and the Adolescent Brain: Is It Time for a Paradigm Shift?
Authors: Luciana Monica , Collins Paul F.
Published: August 2012

It can be argued that adolescents’ decision making is biased more by motivational factors than by cognitively driven calculations of outcome probabilities. Brain‐based models, derived from structural and functional neuroimaging perspectives to account for this bias, have focused on purported differences in rates of development of motivational and regulatory‐control systems. This article proposes a neurochemically based framework for understanding adolescents’ behavioral biases and suggests that there should be an increased focus on the dopaminergic substrates of incentive motivation, which increases into adolescence and decreases thereafter. The article also discusses the manner in which this increase interacts with executive control systems in affecting self‐regulation.
Positive Development of Minority Children: Introduction to the Special Issue
Authors: Cabrera Natasha J. , Beeghly Marjorie , Eisenberg Nancy
Published: August 2012

This special issue highlights research that responded to the Society for Research on Child Development's Ethics and Racial Issues Committee's call for articles on the positive development of minority children. The call was motivated by committee's goal of promoting developmental research on ethnic minority children and adolescents. The articles in this issue report on cutting‐edge research that uses dynamic, integrative bioecological, and cultural models to examine the positive development of ethnic minority children. Collectively, they indicate new directions at conceptual, methodological, and empirical levels that can guide further research on the strengths of minority families.
Comparison of expectations of physicians and patients with rheumatoid arthritis for rheumatology clinic visits: a pilot, multicenter, international study
Authors: Wen Hongyan , Ralph Schumacher H. , Li Xiaofeng , Gu Jieruo , Ma Li , Wei Hua , Yokogawa Naoto , Shiroto Katsuaki , Baker Joshua F. , Dinnella Janet , Ogdie Alexis
Published: August 2012

Aim

To describe and compare expectations of patients with rheumatoid arthritis (RA) and their physicians with regard to what is most important to achieve during a rheumatology clinic visit.

Methods

Subjects were RA patients enrolled in four centers from China, one from Japan and one from the USA, and rheumatologists at those centers. The questionnaires were provided at clinics and patients were asked to list their three top priorities for the rheumatology clinic visit. Physicians were contacted separately and asked to give three general expectations, not for specific visits. We classified clinical expectations into a series of 24 terms for patients and 17 for physicians. We compared physicians' to patients' responses, compared expectations among centers in China, Japan and the USA, and evaluated relationships between patients' responses and age, gender, nationality, disease duration and DAS‐28 (Disease Activity Score‐28).

Results

Patients' clinical expectations for visits focused primarily on control of pain (63.7%), improvement of function (49.3%) and discussion of effects of medication (38.1%). Physicians also included control of pain (59.5%), but also emphasized inquiry about drug side‐effects (47.8%) and objective assessment of disease activity (41.4%). We found no differences related to patients' gender, disease duration and DAS‐28, but there were some differences related to age and nationality.

Conclusion

We found some agreement and some discordance of clinical expectations between RA patients and physicians. There appear to be some different expectations in different countries. Findings from this pilot survey may help physicians consider patients' expectations in planning rheumatology clinic visits and may lead to further hypothesis‐driven studies.
Current considerations for the management of musculoskeletal pain in Asian countries: a special focus on cyclooxygenase‐2 inhibitors and non‐steroid anti‐inflammation drugs
Authors: Pongparadee Chaudakshetrin , Penserga Ester , Lee David Jeng‐Shiang , Chen Shun‐le , Gill Ranjit Singh , Hamid Abdulbar , Kumthornthip Witsanu , Liu Yi , Meliala Lucus , Misbach H Jusuf , Tan Kian Hian , Yeap Swan Sim , Yeo Sow Nam , Lin Hsiao Yi
Published: August 2012

Chronic pain is a complex problem that eludes precise definition and can be clinically difficult to diagnose and challenging to treat. In the Asia‐Pacific region, prevalence estimates that chronic pain ranges from 12% to 45% of the population, with musculoskeletal, rheumatic or osteoarthritis pain making up the majority of the disease burden. Implementation of current management guidelines into routine clinical practice has been challenging and as a result, patients with musculoskeletal pain are often poorly managed. For these reasons, a multidisciplinary Chronic Pain Advisory Board of leading physicians from various Asian countries was convened to explore ways to improve treatment and compliance, especially among patients with osteoarthritis and rheumatoid arthritis. We have identified a number of unmet therapeutic needs and prioritized initiatives with the potential to contribute toward a more integrated approach to chronic pain management. Key priorities included using evidence‐based interventions as recommended by current guidelines, particularly those aspects pertinent to addressing treatment priorities in Asia (e.g., patient compliance), and the incorporation of cyclooxygenase‐2 inhibitors and non‐steroid anti‐inflammation drugs into the management algorithms for osteoarthritis and rheumatoid arthritis. Treatment must be individualized for each patient based on efficacy, side‐effect profile and drug accessibility. Further studies are required to examine head‐to‐head comparisons among analgesics, combinations of analgesics and long‐term efficacy outcomes. Our increasing understanding of the problem combined with the promise of new therapy options offers hope for improved management of musculoskeletal pain in Asian countries.
Metronidazole alone or with amoxicillin as adjuncts to non‐surgical treatment of chronic periodontitis: a 1‐year double‐blinded, placebo‐controlled, randomized clinical trial
Authors: Feres Magda , Soares Geisla Mary Silva , Mendes Juliana Alethusa Velloso , Silva Maike Paulino , Faveri Marcelo , Teles Ricardo , Socransky Sigmund S. , Figueiredo Luciene Cristina
Published: August 2012

Aim

To evaluate the effects of the adjunctive use of metronidazole (MTZ) or MTZ + amoxicillin (AMX) in the treatment of generalized chronic periodontitis (ChP). A secondary aim was to examine a possible added effect of chlorhexidine to these therapies.

Methods

One hundred and eighteen subjects received scaling and root planing (SRP) only or with MTZ [400 mg/thrice a day (TID)] or MTZ+AMX (500 mg/TID) for 14 days. Half of the subjects in each group rinsed with 0.12% chlorhexidine twice a day (BID) for 2 months. Subjects were clinically monitored at baseline, 3, 6 and 12‐months post‐therapy.

Results

The two antibiotic groups showed lower mean number of sites with probing depth (PD) ≥5 mm and fewer subjects exhibiting ≥9 of these sites at 1‐year post‐treatment. Logistic regression analysis showed that antibiotics were the only significant predictors of subjects presenting ≤4 sites with PD ≥5 mm at 1 year (MTZ+AMX: OR, 13.33; 95%CI, 3.75‐47.39/p = 0.0000; MTZ: OR, 7.26; 95%CI, 2.26‐23.30/p = 0.0004). The frequency of adverse events did not differ between the two antibiotic treatments (p > 0.05). The chlorhexidine subgroups showed a trend (p > 0.05) to present fewer residual sites ≥5 mm compared with the placebo subgroups at 1 year.

Conclusion

Treatment of generalized ChP is significantly improved by the adjunctive use of MTZ+AMX and MTZ.
Ischemic injury promotes Keap1 nitration and disturbance of antioxidative responses in endothelial cells: a potential vasoprotective effect of melatonin
Authors: Tao Rong‐rong , Huang Ji‐Yun , Shao Xue‐jing , Ye Wei‐feng , Tian Yun , Liao Mei‐hua , Fukunaga Kohji , Lou Yi‐jia , Han Feng , Lu Ying‐mei
Published: August 2012

Clinical epidemiology has indicated that the endothelial injury is a potential contributor to the pathogenesis of ischemic neurovascular damage. In this report, we assessed S‐nitrosylation and nitration of Keap1 to identify downstream nitric oxide redox signaling targets into endothelial cells during ischemia. Here, oxygen–glucose deprivation (OGD) exposure initiates the nuclear import of Keap1 in endothelial cells, which interacted with nuclear‐localized Nrf2, as demonstrated through co‐immunoprecipitation and immunocytochemical assay. Paralleling the ischemia‐induced nuclear import of Keap1, increased nitrotyrosine immunoreactivity in endothelial cells was also observed. Consistently, the addition of peroxynitrite provoked nuclear import of Keap1 and a concomitant Nrf2 nuclear import in the endothelial cells. Importantly, pharmacological inhibition of nitrosative stress by melatonin partially inhibited the OGD‐induced constitutive nuclear import of Keap1 and subsequently disturbance of Nrf2/Keap1 signaling. Moreover, the effect of melatonin on nitration and S‐nitrosylation of keap1 was examined in endothelial cells with 6 hr OGD exposure. Here, we demonstrated that OGD induced tyrosine nitration of Keap1, which was blocked by melatonin treatment, while there were no significant changes in S‐nitrosylation of Keap1. The specific amino acid residues of Keap1 involved in tyrosine nitration were identified as Y473 by mass spectrometry. Moreover, the protective role of melatonin against damage to endothelial tight junction integrity was addressed by ZO‐1 expression, paralleled with the restored heme oxygenase‐1 levels during OGD. Together, our results emphasize that upon nitrosative stress, the protective effect of melatonin on endothelial cells is likely mediated at least in part by inhibition of ischemia‐evoked protein nitration of Keap1, hence contributing to relieve the disturbance of Nrf2/Keap1 antioxidative signaling.
Apoptotic mechanisms are involved in the death of Strongyloides venezuelensis after triggering of nitric oxide
Authors: Ruano A. L. , López‐Abán J. , Gajate C. , Mollinedo F. , De Melo A. L. , Muro A.
Published: August 2012

Despite progress in understanding the role of nitric oxide (NO) in the pathogenesis of helminth infections, the role in strongyloidosis is unknown. Firstly, we studied the production of NO in mice infected with Strongyloides venezuelensis as well as in macrophage cultures stimulated with parasite antigens. Somatic larvae 3 (L3) and excretory–secretory female antigens stimulate specific NO production measured by Griess reaction and expression of inducible NO synthase by RT‐PCR and quantitative PCR. Moreover, mice infected with S. venezuelensis produce NO in migration stages. Secondly, we analysed the effect of NO production on L3 and females of S. venezuelensis using NO donors such as diethylenetriamine and 3,3‐bis(aminoethyl)‐1‐hydroxy‐2‐oxo‐1‐triazene. Parasites died after NO donor treatment in a dose‐dependent manner. Finally, apoptotic mechanisms are involved in the death of S. venezuelensis larvae.
Computer‐aided lymph node segmentation in volumetric CT data
Authors: Beichel Reinhard R. , Wang Yao
Published: August 2012

Purpose:

The purpose of this work was to develop and validate a computer‐aided method for the 3D segmentation of lymph nodes in CT images. The proposed method can be utilized to facilitate applications like biopsy planning, image guided radiation treatment, or assessment of response to therapy.

Methods:

An optimal surface finding based lymph node segmentation method was developed. Based on the approximate center point of a lymph node of interest, a graph is generated, which represents the local neighborhood around the lymph node at discrete locations (graph nodes). A cost function is calculated based on a weighted edge and region homogeneity term. By means of optimization, a surface‐based segmentation of the lymph node is derived. In addition, an interactive segmentation refinement algorithm was developed, which allows the user to quickly correct segmentation errors, if needed. For assessment of segmentation accuracy, 111 lymph nodes of mediastinum, abdomen, head/neck, and axillary regions from 35 volumetric CT scans were utilized. For accuracy analysis, lymph nodes were divided into three test sets based on lymph node size and spatial resolution of the CT scan. The average lymph node size for test set I, II, and III was 1056, 1621, and 501 mm3, respectively. Spatial resolution of test set II was lower than for test sets I and III. To generate an independent reference standard for comparison, all 111 lymph nodes were segmented by an expert with a live wire approach.

Results:

All test sets were segmented with the proposed approach. Out of the 111 lymph nodes, 40 cases (36%) required computer‐aided refinement of initial segmentation results. The refinement typically required 10 s per lymph node. The mean and standard deviation of the Dice coefficient for final segmentations was 0.847 ± 0.061, 0.836 ± 0.058, and 0.809 ± 0.070 for test sets I, II, and II, respectively. The average signed surface distance error was 0.023 ± 0.171, 0.394 ± 0.189, and 0.001 ± 0.146 mm for test sets I, II, and II, respectively. The time required for locating the approximate center point of a target lymph node in a scan, generating an initial OSF segmentation, and refining the segmentation, if needed, is typically less than one minute.

Conclusions:

Segmentation of lymph nodes in volumetric CT images is a challenging task due to partial volume effects, nearby strong edges, neighboring structures with similar intensity profiles and potentially inhomogeneous density of lymph nodes. The presented approach addresses many of these obstacles. In the majority of cases investigated, the initial segmentation method delivered results that did not require further processing. In addition, the computer‐aided segmentation refinement framework was found to be effective in dealing with potentially occurring segmentation errors.
Quantification of differences in the effective atomic numbers of healthy and cancerous tissues: A discussion in the context of diagnostics and dosimetry
Authors: Taylor M. L.
Published: August 2012

Purpose:

There are a range of genetic and nongenetic factors influencing the elemental composition of different human tissues. The elemental composition of cancerous tissues frequently differs from healthy tissue of the same organ, particularly in high‐Z trace element concentrations. For this reason, one could suggest that this may be exploited in diagnostics and perhaps even influence dosimetry.

Methods:

In this work, for the first time, effective atomic numbers are computed for common cancerous and healthy tissues using a robust, energy‐dependent approach between 10 keV and 100 MeV. These are then quantitatively compared within the context of diagnostics and dosimetry.

Results:

Differences between effective atomic numbers of healthy and diseased tissues are found to be typically less than 10%. Fibrotic tissues and calcifications of the breast exhibit substantial (tens to hundreds of percent) differences to healthy tissue. Expectedly, differences are most pronounced in the photoelectric regime and consequently most relevant for kV imaging/therapy and radionuclides with prominent low‐energy peaks. Cancerous tissue of the testes and stomach have lower effective atomic numbers than corresponding healthy tissues, while diseased tissues of the other organ sites typically have higher values.

Conclusions:

As dose calculation approaches improve in accuracy, there may be an argument for the explicit inclusion of pathologies. This is more the case for breast, penile, prostate, nasopharyngeal, and stomach cancer, less so for testicular and kidney cancer. The calculated data suggest dual‐energy computed tomography could potentially improve lesion identification in the aforementioned organs (with the exception of testicular cancer), with most import in breast imaging. Ultimately, however, the differences are very small. It is likely that the assumption of a generic “tissue ramp” in planning will be sufficient for the foreseeable future, and that theZ differences do not notably aid lesion detection beyond that already facilitated by differences in mass density.
Human contrast‐detail performance with declining contrast
Authors: Walz‐Flannigan Alisa , Babcock Ben , Kagadis George C. , Wang Jihong , Langer Steve G
Published: August 2012

Purpose:

How do display settings and ambient lighting affect contrast detection thresholds for human observers? Can recalibrating a display for high ambient lighting improve object detection?

Methods:

Contrast/detail (CD) threshold detection performance was measured for observers using four color displays with varying overall contrast (e.g., differing maximum luminance and ambient lighting conditions). Detailed mapping of contrast detection performance (for fixed object size) was tracked as a function of: display maximum luminance, ambient lighting changes (with and without recalibrating for the higher ambience), and the performance of radiologistsvs. nonradiologists.

Results:

The initial phase was analyzed with a hierarchical linear model of observer performance using: background gray level, maximum display luminance, and radiologistvs. nonradiologist. The only statistically significant finding was a maximum luminance of 100 cd/m2 display performing worse than a baseline peak of 400 cd/m2. The second phase examined ambient lighting effects on detection thresholds. Background gray level and maximum display luminance were examined coupled with ambient lighting for: baseline at 30, 435 uncorrected, and 435 lx with display recalibration for the ambient conditions. Results showed ambient correction improved sensitivity for small background digital driving level, but not at higher luminance backgrounds.

Conclusions:

For CD study, nonradiologist observers can be used without loss of applicability. Contrast detection thresholds improved significantly between displays with peak luminance from 100 cd/m2 to 200 cd/m2, but improvement beyond that was not statistically significant for contrast detection thresholds in a reading room environment. Applying a calibration correction at high ambience (435 lx) improved detection tasks primarily in the darker background regions.
Calculation of strain images of a breast‐mimicking phantom from 3D CT image data
Authors: Kim Jae G. , Aowlad Hossain A. B. M. , Shin Jong H. , Lee Soo Y.
Published: August 2012

Purpose:

Elastography is a medical imaging modality to visualize the elasticity of soft tissues. Ultrasound and MRI have been exclusively used for elastography of soft tissues since they can sensitize the tissues’ minute displacements of an order ofμm. It is known that ultrasound and MRI elastography show cancerous tissues with much higher contrast than conventional ultrasound and MRI. To evaluate possibility of combining elastography with x‐ray imaging, we have calculated strain images of a breast‐mimicking phantom from its 3D CT image data.

Methods:

We first simulated the x‐ray elastography using a FEM model which incorporated both the elasticity and x‐ray attenuation behaviors of breast tissues. After validating the x‐ray elastography scheme by simulation, we made a breast‐mimicking phantom that contained a hard inclusion against soft background. With a micro‐CT, we took 3D images of the phantom twice, changing the compressing force to the phantom. From the two 3D phantom images taken with two different compression ratios, we calculated the displacement vector maps that represented the compression‐induced pixel displacements. In calculating the displacement vectors, we tracked the movements of image feature patterns from the less‐compressed‐phantom images to the more‐compressed‐phantom images using the 3D image correlation technique. We obtained strain images of the phantom by differentiating the displacement vector maps.

Results:

The FEM simulation has shown that x‐ray strain imaging is possible by tracking image feature patterns in the 3D CT images of the breast‐mimicking phantom. The experimental displacement and strain images of a breast‐mimicking phantom, obtained from the 3D micro‐CT images taken with 0%–3% compression ratios, show behaviors similar to the FEM simulation results. The contrast and noise performance of the strain images improves as the phantom compression ratio increases.

Conclusions:

We have experimentally shown that we can improve x‐ray strain image quality by applying 3D image correlation to the two sets of 3D CT images taken with different compression ratios. But, we need further investigations to evaluate the strain imaging performance considering the noise and decorrelation effects as well as the extra dose caused by two scans.
Hippocampal Place Fields Emerge upon Single-Cell Manipulation of Excitability During Behavior
Authors: Lee Doyun , Lin Bei-Jung , Lee Albert K.
Published: August 2012

How to Make a Place Cell

Hippocampal place cells have been studied for more than 40 years, yet the mechanisms underlying their remarkable spatial tuning are still not established. Using whole-cell patch-clamp recordings in freely moving rats,

Lee
et al.

(p.
849
) changed the baseline membrane potential in hippocampal pyramidal neurons. Place fields arose spontaneously in otherwise silent pyramidal cells after depolarization when the membrane voltage reached a threshold. Place cells in the hippocampus and grid cells in the entorhinal cortex are thought to provide the framework for spatial navigation in an animal. However, it is still unclear how the hexagonal symmetry that is so prominent in grid cells emerges. While recording from the entorhinal cortex and in the pre- and parasubiculum during spatial behavior in the rat,

Krupic
et al.

(p.
853
) discovered that many forms of spatial periodicity exist in neurons in these structures. The grid cells seem to reflect a subset of this larger set, generated by self-organized dynamics.
A TOG:αβ-tubulin Complex Structure Reveals Conformation-Based Mechanisms for a Microtubule Polymerase
Authors: Ayaz Pelin , Ye Xuecheng , Huddleston Patrick , Brautigam Chad A. , Rice Luke M.
Published: August 2012

All TOGether Now

αβ-Tubulin is the polymerizing subunit of microtubules, which are dynamic polymers that have essential roles in cell division and intracellular organization. TOG domains are αβ-tubulin binding modules that occur in the evolutionarily conserved Stu2p/XMAP215 family of proteins and promote microtubule elongation.

Ayaz
et al.

(p.
857
) used crystallographic and biochemical experiments to reveal that the TOG1 domain interacts with guanosine triphosphate–bound αβ-tubulin in a conformation-selective manner, binding preferentially to a “curved,” microtubule-incompatible conformation. The binding mode apparently excludes analogous binding of a second TOG domain to the same heterodimer and may help to ensure polarized growth of microtubules.
Neural Representations of Location Composed of Spatially Periodic Bands
Authors: Krupic Julija , Burgess Neil , O’Keefe John
Published: August 2012

How to Make a Place Cell

Hippocampal place cells have been studied for more than 40 years, yet the mechanisms underlying their remarkable spatial tuning are still not established. Using whole-cell patch-clamp recordings in freely moving rats,

Lee
et al.

(p.
849
) changed the baseline membrane potential in hippocampal pyramidal neurons. Place fields arose spontaneously in otherwise silent pyramidal cells after depolarization when the membrane voltage reached a threshold. Place cells in the hippocampus and grid cells in the entorhinal cortex are thought to provide the framework for spatial navigation in an animal. However, it is still unclear how the hexagonal symmetry that is so prominent in grid cells emerges. While recording from the entorhinal cortex and in the pre- and parasubiculum during spatial behavior in the rat,

Krupic
et al.

(p.
853
) discovered that many forms of spatial periodicity exist in neurons in these structures. The grid cells seem to reflect a subset of this larger set, generated by self-organized dynamics.
Reproduction in Early Amniotes
Authors: Sander P. Martin
Published: August 2012

Recent fossil finds help to explain why the early fossil record is dominated by live-bearing amniotes, although live-bearing amniotes evolved later than egg-laying ones.
Mixed-Phase Oxide Catalyst Based on Mn-Mullite (Sm, Gd)Mn
2
O
5
for NO Oxidation in Diesel Exhaust
Authors: Wang Weichao , McCool Geoffrey , Kapur Neeti , Yuan Guang , Shan Bin , Nguyen Matt , Graham Uschi M. , Davis Burtron H. , Jacobs Gary , Cho Kyeongjae , Hao Xianghong (Kelly)
Published: August 2012

Cleaning Diesel Exhaust

One strategy for removing pollutants from diesel engine exhaust is to trap the unburned carbon soot and then to combust the soot with the NO
2
that is generated from NO; the two pollutants are then converted to N
2
and CO
2
. Diesel exhaust is relatively cold, compared to gasoline engine exhaust, and conversion of NO to NO
2
has required the use of platinum catalysts.

W. Wang
et al.

(p.
832
) now report that a more earth-abundant catalyst, based on Mn-mullite (Sm, Gd)Mn
2
O
5
metal oxides was able to oxidize NO in simulated diesel exhaust at temperatures as low as 75°C. Spectroscopic studies and quantum chemical modeling suggested that Mn-nitrates formed on Mn-Mn dimer sites were the key intermediates responsible for NO
2
formation.
Cuprates Get Orders to Charge
Authors: Tranquada John M.
Published: August 2012

Modulations in the charge density provide a clue while adding complexity to the story of high-temperature superconductivity.
A Swiss Army Knife of Immunity
Authors: Brouns Stan J. J.
Published: August 2012

A duplex of two small RNA molecules directs the destruction of intrusive foreign DNA in bacteria.
An Ancient Portal to Proteolysis
Authors: Matouschek Andreas , Finley Daniel
Published: August 2012

The discovery in archaea of an alternative proteasome based on Cdc48 provides insights into the evolution of protein degradation machines.
Capably Communicating Science
Authors: Leshner Alan I.
Published: August 2012

There is no shortage of topics where policy-makers or other members of the public seem to persistently misunderstand, misrepresent, or disregard the underlying science: climate change, genetically modified foods, vaccines, or evolution, among others. Consequently, the call for scientists to do a better job of communicating both the meaning and the nature of their work is getting louder. Public understanding of science not only affects people's ability to appreciate and make full use of the products of science, it also contributes to the extent of support for scientific research. Yet far too many scientists are reluctant to engage with people outside their own community. The reasons range from a belief that this responsibility lies outside a scientist's “job description” to an expressed ignorance about how to go about it. In an attempt to find better solutions to this problem, the U.S. National Academy of Sciences convened a meeting of over 450 scientists, policy-makers, journalists, and other professional communicators to examine the underlying dynamics of science communication.
*
The good news is that empirical studies across many disciplines, particularly in the behavioral and social sciences, are providing very useful baseline information about public attitudes and knowledge about science, as well as some fundamental principles that can help guide scientists to engage more effectively with both the public and policy-makers.
†
In Mock Case, Biological Evidence Reduces Sentences
Authors: Miller Greg
Published: August 2012

In a fictional case, judges presented with biological evidence of psychopathy handed out reduced sentences, researchers report in this week's issue.
Mountains of Data
Authors: Service Robert F.
Published: August 2012

A famous mountaineer and Microsoft researchers are blending images, data, and computer models to document how changing climate is affecting the Himalaya.