bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidative stress induced by chromium (VI) in bone of suckling rats
Authors: Soudani Nejla , Ibtissem Ben Amara  , Troudi Afef , Bouaziz Hanen , Boudawara Tahia , Zeghal Najiba
Published: May 2011

Exposure to hexavalent chromium Cr(VI) compounds is of concern in many Cr-related industries and their surrounding environments. K2Cr2O7 is widely recognized as an animal and human carcinogen, mutagen, and teratogen. The present study investigated the bone maturity of suckling rats whose mothers were treated with K2Cr2O7. Experiments were carried out on female Wistar rats given 700 ppm of K2Cr2O7 in their drinking water from the 14th day of pregnancy until day 14 after delivery. Exposing dams to K2Cr2O7 caused disorders in the bone of their progeny. As corollary to this, malondialdehyde levels increased, while glutathione, a non-protein thiol and vitamin C decreased. Alteration of the antioxidant system in the treated group was also confirmed by the significant decline of superoxide dismutase, catalase, and glutathione peroxidase activities. Furthermore, K2Cr2O7 induced changes in bone mineralization, especially calcium and phosphorus levels, which decreased. Whereas, in plasma and urine, they increased and decreased inversely. These results suggest that K2Cr2O7 accelerated bone resorption activity. In fact, in treated pups, total tartrate-resistant acid phosphatase, which reflected bone resorption, was enhanced while total alkaline phosphatase, which reflected bone formation, was reduced. The impairment of bone function was corresponded histologically.
Paraphenylene diamine hair dye poisoning in an adolescent
Authors: Abdelraheem Mohamed , Ali El-Tigani , Hussien Rasha , Zijlstra Eduard
Published: May 2011

A 14-year-old female was referred to the pediatric nephrology unit with a short history of progressive angio-oedema of the face requiring tracheostomy. She ingested an unusual substance which caused swollen tongue, cervical oedema and dark coloured brown urine. These clinical features with the laboratory tests confirmed the diagnosis of paraphenylene diamine (PPD) poisoning. Psychological assessment confirmed that the child had severe depression. The suicide attempt was just immediately after failure in the final qualifying examination to secondary school. She did not have any family support but she used to be punished in different ways. In Sudan PPD in its pure form is available in the local market and until recently there was no restrictions for its use or trade. Adolescents are well aware of its toxic effects and it is commonly used to attempt suicide. Legislation and laws should prevent its use in different hair dye formulations and look for another substitute. Clinical management is hampered by the lack of a rapid diagnostic test; no other treatment other than supportive measures can be offered.
Different Associations of Periventricular and Deep White Matter Lesions with Cognition, Neuropsychiatric Symptoms, and Daily Activities in Dementia
Authors: Kee Hyung Park  , Lee Jun-Young , Na Duk L. , Seong Yoon Kim  , Cheong Hae-Kwan , So Young Moon  , Shim Yong S. , Kyung Won Park  , Ku Bon D. , Seong Hye Choi  , Joo Hwan , Joong Sun Lee  , Seok Min Go  , Sook Hui Kim  , SangYun Kim  , Kyung Ryeol Cha  , Lee Juwon , Sang Won Seo
Published: May 2011

We investigated the associations of periventricular white matter hyperintensities (PWMHs) and deep white matter hyperintensities (DWMHs) with cognition, activities of daily living (ADLs), and neuropsychiatric symptoms in dementia. This was a hospital-based MRI300 study. We recruited patients newly diagnosed with mild-to-moderate dementia caused either by Alzheimer’s disease or subcortical ischemic vascular dementia from 13 dementia clinics at university or general hospitals in South Korea. We enrolled 289 patients aged over 50 from August 2007 to March 2008. We compared cognition, ADLs, and neuropsychiatric symptoms among 3 groups according to the severities of PWMHs and DWMHs, respectively, by adjusting for age, vascular risk factors, and level of other WMHs. A higher severity of PWMHs was related to lower cognitive function and severer neuropsychiatric symptoms, whereas basic ADLs were associated with DWMH. Both PWMHs and DWMHs exhibited different associations with cognition, neuropsychiatric symptoms, and daily activities.
Critical approaches to financial delegation in public education in post-communist Romania
Authors: Popescu Ana-Cristina
Published: May 2011

The article focuses on tracking financial delegation (introduced nationally in January 2010) as part of the broader process of education restructuring and decentralisation in post-communist Romania. The aim is to critically pinpoint some of the challenges specific to the Romanian context, such as the multitude of policies and legislation (due to the fluidity of the political system and hence of the Ministry of Education’s leadership), lack of consistency in the implementation of reforms, doubled by inappropriate corresponding financial legislation and communication between the various layers of responsibility (the Ministry of Education on the one hand and the Ministries of Public Finances and Administration and Interior on the other). One year after the enactment of financial delegation, Romanian education remains a terrain of challenges; many aspects are still unclear with regard to its implementation, outcomes and long-term effects on the system and its actors which ask for further research.
A new research agenda for educational leadership and policy
Authors: Ball Stephen J.
Published: May 2011

This paper identifies some new research issues and sketches out some new research questions for education policy and leadership researchers as a response to ongoing changes in the landscape of English education policy. Three interrelated issues are considered: leadership, values and interests, and ownership. It argues for the need to ask new research questions and also to look in different places for answers to these questions and suggests that researchers need to acquire new research skills and sensibilities, in particular forms of business and financial analysis.
Transactional and transformational leadership in schools in challenging circumstances: a policy paradox
Authors: Smith Phil , Bell Les
Published: May 2011

This article reports on a research project that studied the approaches to leadership adopted by head teachers in one local authority in an area of extreme social deprivation in northern England. Using data from semi-structured interviews which was analysed using three software packages, it examines how far the heads use either transactional or transformational leadership and identifies the factors that lead heads to make leadership choices. It concludes that while heads use both approaches to leadership, they believe that transformational leadership is far more effective in bringing about change which produces successful school development. However, external pressures cause the heads to concentrate far more than they would wish on transactional leadership in spite of the espoused national policy to facilitate school improvement.
Theoretical and experimental investigation into the interaction between a snowboard or ski and an artificial snow surface
Authors: Brooks L E E , Purdy D J , Edmonds S
Published: May 2011

In this study, a model of the contact patch between a snowboard or ski and artificial snow surface is developed. The surface used consists of a uniform bristle structure, the key parameters being the bristle torsional stiffness, spacing, and length, and the coefficient of friction between the bristle and snowboard. The model is shown to capture the general behaviour of the horizontal force generated in the contact patch and by tuning the bristle’s torsional stiffness, an excellent fit was achieved. The model is also capable of predicting the breakdown of the forces in the contact patch and where heating of the snowboard on this type of surface might be a problem.
Investigation of nitrogen-diluted syngas non-premixed flames measured by planar laser-induced fluorescence of hydroxyl and particle image velocimetry
Authors: Guo P , Zang S , Ge B , Tian Y
Published: May 2011

In order to investigate the effects of nitrogen dilution on combustion behaviour of syngas flames, a model combustor with optical access for swirl non-premixed flames was developed. Experimental results from planar laser-induced fluorescence (PLIF) of OH and particle image velocimetry (PIV) are presented. The syngas consists of hydrogen and carbon monoxide of volume fraction ratio kept at 0.78. Up to 60 per cent (by volume) of nitrogen was added into syngas, as well as reference fuels including methane, hydrogen, and carbon monoxide, for dilution. Flow fields obtained by PIV reveal that the averaged typical swirling flow structure is not influenced by dilution content, which has more effect on turbulence intensities in recirculation zones and shear layers. Additionally, analysis of reaction zones and regions of burnt gas from OH-PLIF measurement shows that although syngas flame burns closer to fuel spray exit than methane, the latter shows more combustion stability, probably because of the different stabilization mechanisms for these two flames. With less support from hot burned gases in recirculation zones, the content of hydrogen plays a crucial role in syngas flame stabilization. Experimental results also imply that the increase of dilution content in fuel leads to less flame opening angle and thinner flame base.
Computational modelling and experimental validation of the thermal fusion bonding process in porous fibrous media
Authors: Peksen M , Acar M , Malalasekera W
Published: May 2011

This article presents a computational model of the thermal bonding of nonwovens using convective hot air and its experimental validation. A computational fluid dynamics model based on the continuum modelling approach and the theory of porous media is developed to treat the flow behaviour and heat transfer within the thermal bonding system. The model includes several components of a typical industrial machine including the conveyer belt, drum cover, drum, and the nonwoven web. Experimental measurements are used to supply appropriate boundary conditions for the simulations and to provide data for the validation of the numerically computed results. The model is concluded to be an accurate computational tool that could potentially replace the costly experiments and be employed in product development, process optimization, and machine design.
Nanocomposite biomaterial mimicking aortic heart valve leaflet mechanical behaviour
Authors: Mohammadi H
Published: May 2011

The main problem with polymeric heart valves (which are already biocompatible) is that they usually fail in the long term owing to tearing and calcification of the leaflets under high dynamic tensile bending stress and oxidative reactions with blood. To overcome this shortcoming, it is hypothesized that synthetic valve leaflets which mimic native valve leaflet structure fabricated from fibre-reinforced composite material will optimize leaflet stresses and decrease tears and perforations. The objective of this study is to develop a PVA-BC (polyvinyl alcohol-bacterial cellulose)-based hydrogel that mimics not only the non-linear mechanical properties displayed by porcine heart valves, but also their anisotropic behaviour. By applying a controlled strain to the PVA samples, while undergoing low-temperature thermal cycling, it was possible to create oriented mechanical properties in PVA hydrogels. The oriented stress–strain properties of porcine aortic valves were matched simultaneously by a PVA hydrogel (15 per cent PVA, 0.5 BC cycle 4, 75 per cent initial tensile strain). This novel technique allows the control of anisotropy to PVA hydrogel, and gives a broad range of control of its mechanical properties, for specific medical device applications.
Pressure waves in the aorta during isolated abdominal belt loading: the magnitude, phasing, and attenuation
Authors: Arregui-Dalmases C , Del Pozo E , Stacey S , Kindig M , Lessley D , Lopez-Valdes F , Forman J , Kent R
Published: May 2011

While rupture of the aorta is a leading cause of sudden death following motor vehicle crashes, the specific mechanism that causes this injury is not currently well understood. Aortic ruptures occurring in the field are likely due to a complex combination of contributing factors such as acceleration, compression of the chest, and increased pressure within the aorta. The objective of the current study was to investigate one of these factors in more detail than has been done previously; specifically, to investigate the in situ intra-aortic pressure generated during isolated belt loading to the abdomen.

Ten juvenile swine were subjected to dynamic belt loads applied to the abdomen. Intra-aortic pressure was measured at multiple locations to assess the magnitude and propagation of the resulting blood pressure wave. The greatest average peak pressure (113.6 ± 43.5 kPa) was measured in the abdominal aorta. Pressures measured in the thoracic aorta and aortic arch were 70 per cent and 50 per cent, respectively, that measured in the abdominal aorta. No macroscopic aortic trauma was observed.

To the authors’ knowledge the present study is the first one to document the presence, propagation, and attenuation of a transient pressure wave in the aorta generated by abdominal belt loading. The superiorly moving wave is sufficient to generate hydrostatic and intimal shear stress in the aorta, possibly contributing to the hypothesized mechanisms of traumatic aortic rupture.
Inlet protein aggregation: a new mechanism for lubricating film formation with model synovial fluids
Authors: Fan J , Myant C W , Underwood R , Cann P M , Hart A
Published: May 2011

This paper reports a fundamental study of lubricant film formation with model synovial fluid components (proteins) and bovine serum (BS). The objective was to investigate the role of proteins in the lubrication process. Film thickness was measured by optical interferometry in a ball-on-disc device (mean speed range of 2–60 mm/s). A commercial cobalt–chromium (CoCrMo) metal femoral head was used as the stationary component. The results for BS showed complex time-dependent behaviour, which was not representative of a simple fluid. After a few minutes sliding BS formed a thin adherent film of 10–20 nm, which was attributed to protein absorbance at the surface. This layer was augmented by a hydrodynamic film, which often increased at slow speeds. At the end of the test deposited surface layers of 20–50 nm were measured. Imaging of the contact showed that at slow speeds an apparent ‘phase boundary’ formed in the inlet just in front of the Hertzian zone. This was associated with the formation of a reservoir of high-viscosity material that periodically moved through the contact forming a much thicker film. The study shows that proteins play an important role in the film-forming process and current lubrication models do not capture these mechanisms.
Infant mortality rates regressed against number of vaccine doses routinely given: Is there a biochemical or synergistic toxicity?
Authors: Miller Neil Z , Goldman Gary S
Published: May 2011

The infant mortality rate (IMR) is one of the most important indicators of the socio-economic well-being and public health conditions of a country. The US childhood immunization schedule specifies 26 vaccine doses for infants aged less than 1 year—the most in the world—yet 33 nations have lower IMRs. Using linear regression, the immunization schedules of these 34 nations were examined and a correlation coefficient of r = 0.70 ( p < 0.0001) was found between IMRs and the number of vaccine doses routinely given to infants. Nations were also grouped into five different vaccine dose ranges: 12–14, 15–17, 18–20, 21–23, and 24–26. The mean IMRs of all nations within each group were then calculated. Linear regression analysis of unweighted mean IMRs showed a high statistically significant correlation between increasing number of vaccine doses and increasing infant mortality rates, with r = 0.992 ( p = 0.0009). Using the Tukey-Kramer test, statistically significant differences in mean IMRs were found between nations giving 12–14 vaccine doses and those giving 21–23, and 24–26 doses. A closer inspection of correlations between vaccine doses, biochemical or synergistic toxicity, and IMRs is essential.
Tolerance in the Postindustrial City
Authors: van der Waal Jeroen , Houtman Dick
Published: May 2011

This article studies whether and why less educated natives are less ethnocentric in postindustrial Dutch cities than in industrial ones, as suggested by several theories in urban studies. A multilevel analysis of survey data collected among the native working populations (source: Cultural Change in the Netherlands Surveys 2004 and 2006) of 22 Dutch metropolitan agglomerations (sources: Statistics Netherlands Statline and Atlas of Municipalities) confirms that those concerned are indeed less ethnocentric in the most postindustrial cities. This pattern proves not to stem from the better opportunities at the bottom end of the labor market in these cities, as the ethnic competition theory suggests, but from the more tolerant cultural climate in these cities, as emphasized by Richard Florida in his work on creative cities.
Survival Strategies of Male Homeless Adolescents
Authors: Hein Laura C.
Published: May 2011

Background: A total of 1.7 million youth are homeless in America and nearly half are lesbian, gay, bisexual, or transgender. The purpose of this study is to investigate survival strategies, anxiety, and self-esteem among male homeless adolescents. Objectives: This study tested two hypotheses: (a) Survival strategies of homeless adolescents differ by sexual orientation/gender identity. (b) There is a relationship between survival strategies and sexual orientation/gender identity, amount of time homeless, self-esteem, and state/trait anxiety. Design: A comparative-descriptive study was conducted in six large cities. Seventy 16- to 20-year-old homeless male adolescents were recruited. Results: Survival strategies did not significantly vary by sexual orientation; however, some differences may be of clinical relevance. Conclusions: Homeless youth of all sexual orientations/gender identities were using diverse strategies to survive. Psychiatric nurses are in a unique position to assist these youth.
Sexual Homicide and Sexual Violence-Associated Homicide: Findings From the National Violent Death Reporting System
Authors: Smith Sharon G. , Basile Kathleen C. , Karch Debra
Published: May 2011

Sexual violence is linked to homicide in a variety of ways. In this study the authors analyzed narratives that described the homicide circumstances of 285 homicide victims from 17 states who participated in the National Violent Death Reporting System during 2003-2007. The authors discuss a narrative analysis conducted using qualitative methods that revealed four categories of homicide linked to sexual violence, in addition to classic sexual homicide. In this article, the authors provide descriptions of the circumstances involved in sexual violence—related homicides, narrative examples of each type, and offer an expanded classification of these crimes. The analyses reveal specific types of homicide that are related to the perpetration of sexual violence, some of which have received little to no attention in the sexual violence or homicide literature. The study demonstrates the potential of the NVDRS as a strong data source for sexual homicides as well as other forms of homicide. Finally, the authors discuss implications for ongoing monitoring of homicides that are linked to sexual violence.
Repairing Interatrial Septal Defects From the Operating Room to the Cardiac Catheterization Laboratory: 2D or Not 2D?
Authors: Perry Tjorvi , Shook Douglas C. , Nhuch Fani , Chou Henry , Shernan Stanton , Gross Wendy L.
Published: May 2011

Uncorrected congenital interatrial septal defect can be found in nearly a third of all adults and are associated with significant morbidity, including pulmonary hypertension, right-heart failure, atrial arrhythmias, and paradoxical embolic stroke. With advancing technology, percutaneous closure of atrial septal defects has become a viable alternative to open surgical repair. In this review, the authors provide 3 examples in which 3-dimensional interventional transesophageal echocardiogram effectively provided more precise visualization of the dynamic surface and geometry of the atrial septum and related structures than 2-dimensional TEE, permitting accurate sizing and repair of the defects.
Acute pain management in trauma
Authors: Keene Damian D , Rea William E , Aldington Dominic
Published: May 2011

Major trauma affects more than 20 000 people per annum in the UK. Some three quarters of these patients will experience moderate-to-severe pain either as a direct result of their injuries or during the course of their management. Acute pain is associated with activation of the stress response. Poorly treated pain can also result in considerable psychological stress, which can impact on ongoing treatment and rehabilitation post-injury. Additionally, pain may persist to become chronic pain — up to two-thirds of major trauma victims report ongoing pain severe enough to affect quality of life for several years after injury. Delivery of effective analgesia has been shown to reduce the adverse effects on outcome associated with undertreated pain.
A comparative profile of the Internet gambler: Demographic characteristics, game-play patterns, and problem gambling status
Authors: Wood Robert T. , Williams Robert J.
Published: May 2011

Overcoming the methodological limitations of many previous studies, the present study employs a two-phased approach to data collection, and a weighted approach to data analysis, thereby obtaining survey data from 1954 Internet gamblers and 5967 non-Internet gamblers. Using this data, the authors examine: (1) the comparative demographic and health characteristics of Internet versus land-based gamblers; (2) the characteristics predictive of Internet gambling; (3) the game-play patterns of Internet gamblers; (4) the comparative gambling expenditures of Internet versus land-based gamblers; and (5) the comparative rate of problem gambling among Internet versus land-based gamblers. The article concludes with a discussion of the methodological implications the present study holds for future research. Moreover, in light of the key finding that Internet gamblers are three to four times more likely to have a gambling problem, the article concludes with a discussion of relevant theoretical and policy implications.
Bypassing the Representational Filter? Minority Rights Policies under Direct Democracy Institutions in the U.S. States
Authors: Lewis Daniel C.
Published: May 2011

One common critique of direct democracy posits that minority rights are endangered by institutions like ballot initiatives and referenda. Empirical research testing this claim, however, has produced conflicting results that leave the question of direct democracy's effect on minority rights open to debate. This study extends previous research by providing a more direct test of this criticism—it compares anti-minority policy proposals from direct democracy states to similar proposals from states without direct democracy institutions. The author examines both ballot proposals and traditional legislative bills to account for both the direct and indirect effects of direct democracy. Analyzing anti-minority proposals from all 50 states from 1995 to 2004 shows that direct democracy states are more likely to pass these proposals than states without direct democracy institutions.
Mimicry of Dynamic Emotional and Motor-Only Stimuli
Authors: Moody Eric J. , McIntosh Daniel N.
Published: May 2011

Simple reciprocal matching behaviors, such as facial mimicry, appear fundamental to social development and interpersonal processes. Identifying mechanisms and moderators of these reactions to others' behaviors is thus important to understanding basic social–emotional functioning and specific clinical syndromes. This experiment extends early electromyographic (EMG) research (Berger & Hadley, 1975) to explore whether rapid, subtle mimicry involves a general motor-matching mechanism (e.g., the mirror neuron system) or if it is related solely to emotional processes. The EMG measured responses to short, dynamic videos of smiling, scowling, stuttering, and arm wrestling. Although mimicry of emotional stimuli was greater than to nonemotional stimuli, participants matched both nonemotional mouth movements and facial expressions of emotions. Mimicry of arm motions was not significant. Individuals' levels of mimicry of emotional and nonemotional were positively correlated. Findings suggest that both motor and affective processes are involved in producing rapid mimetic reactions to dynamic stimuli.
Treatment options for high-risk chronic lymphocytic leukaemia
Authors: Hewamana Saman , Dearden Claire
Published: May 2011

Chronic lymphocytic leukaemia (CLL) is the most common form of leukaemia in the Western world. The natural history of CLL is extremely variable with a survival time from initial diagnosis that ranges from 2 to more than 20 years. Understanding the clinical diversity and allowing the subclassification of CLL into various prognostic groups not only assists in predicting future outcome for patients, but also helps to direct treatment decisions. Chlorambucil and fludarabine were the standard therapy for CLL for decades. Randomized studies have reported superior overall response and progression-free survival (PFS) for fludarabine compared with alkylator-based therapy and for the fludarabine–cyclophospamide (FC) combination over fludarabine alone. More recently the addition of rituximab to the FC regimen (R-FC) has shown significant improvement in overall response, PFS and overall survival compared with FC alone. However, there are patients for whom this regimen still provides less satisfactory results. Within the above studies CLL patients who have some of the poorer prognostic markers, such as unmutated IgVH genes and/or high beta-2 microglobulin (B2M), and those who fail to achieve a minimal residual disease (MRD) negative remission are likely to have a shorter PFS compared with those without these features. Various strategies have been explored to improve the outcome for such patients. These include the addition of agents to a frontline R-FC regimen, use of consolidation and consideration of maintenance.

The only group that can be clearly identified pretreatment for whom conventional fludarabine-based therapies produce significantly inferior response rates, PFS and overall survival are the patients who harbour a genetic fault; deletion or mutation or a combination of deletion and mutation of tumour protein p53 ( TP53). TP53 inactivation is a less common finding at first treatment but becomes much more common in fludarabine-refractory patients. Alemtuzumab and high-dose corticosteroids have been shown to be effective in this group of CLL patients. Trials combining these two agents have shown improved responses, particularly for those patients with bulky nodal disease for whom alemtuzumab alone may be insufficient. Since the duration of responses remains relatively short, suitable patients should be considered for allogeneic stem cell transplantation according to the European Group for Blood and Marrow Transplantation (EBMT) guidelines. Furthermore, there are a number of other new treatments on the horizon, including humanized antibodies directed against novel targets and small-molecule inhibitors.
Effect of reverse transcriptase inhibitors on LINE-1 and Ty1 reverse transcriptase activities and on LINE-1 retrotransposition
Authors: Dai Lixin , Huang Qing , Boeke Jef D
Published: May 2011

Background

LINE-1s (L1, Long Interspersed Element-1) are the most abundant autonomous non-LTR retrotransposons in the human genome and replicate by reverse transcription of an RNA intermediate. Full-length L1 encodes two open reading frames (ORF1, ORF2) and ORF2 has reverse transcriptase activity.

Results

Here we expressed human L1 RT in E. coli and the purified protein displayed the same RT activity as that of ORF2p expressed in insect cells. We tested the effect of different reverse transcriptase inhibitors on L1 RT and found that all four tested nucleoside inhibitors efficiently inhibited L1 RT activity competitively. The Ki values of NRTIs were calculated (AZTTP, 16.4 ± 4.21 nM; d4TTP, 0.73 ± 0.22 nM; ddCTP, 0.72 ± 0.16 nM; 3TCTP, 12.9 ± 2.07 nM). L1 RT was less sensitive to non-nucleoside reverse transcriptase inhibitors, among these nevirapine had no effect, even at concentrations up to 500 μM. We also examined the effect of RT inhibitors on L1 retrotransposition efficiency in vivo using a cell-based retrotransposition assay. Similarly, all analog inhibitors decreased L1 retrotransposition frequency with different potencies whereas nevirapine had little or no effect on L1 retrotransposition. For comparison, we also tested the same inhibitors to highly purified RT of an LTR-retrotransposon (Ty1) and found it was less sensitive to NRTIs than L1 RT and has the same inhibition profile as L1 RT to NNRTIs.

Conclusions

These data indicate that bacterially expressed L1 RT is an active reverse transcriptase sensitive to nucleoside RT inhibitors but not to non-nucleoside inhibitors.
Arbuscular mycorrhizal symbiosis elicits shoot proteome changes that are modified during cadmium stress alleviation in Medicago truncatula
Authors: Aloui Achref , Recorbet Ghislaine , Robert Franck , Schoefs Benoît , Bertrand Martine , Henry Céline , Gianinazzi-Pearson Vivienne , Dumas-Gaudot Eliane , Aschi-Smiti Samira
Published: May 2011

Background

Arbuscular mycorrhizal (AM) fungi, which engage a mutualistic symbiosis with the roots of most plant species, have received much attention for their ability to alleviate heavy metal stress in plants, including cadmium (Cd). While the molecular bases of Cd tolerance displayed by mycorrhizal plants have been extensively analysed in roots, very little is known regarding the mechanisms by which legume aboveground organs can escape metal toxicity upon AM symbiosis. As a model system to address this question, we used Glomus irregulare-colonised Medicago truncatula plants, which were previously shown to accumulate and tolerate heavy metal in their shoots when grown in a substrate spiked with 2 mg Cd kg-1.

Results

The measurement of three indicators for metal phytoextraction showed that shoots of mycorrhizal M. truncatula plants have a capacity for extracting Cd that is not related to an increase in root-to-shoot translocation rate, but to a high level of allocation plasticity. When analysing the photosynthetic performance in metal-treated mycorrhizal plants relative to those only Cd-supplied, it turned out that the presence of G. irregulare partially alleviated the negative effects of Cd on photosynthesis. To test the mechanisms by which shoots of Cd-treated mycorrhizal plants avoid metal toxicity, we performed a 2-DE/MALDI/TOF-based comparative proteomic analysis of the M. truncatula shoot responses upon mycorrhization and Cd exposure. Whereas the metal-responsive shoot proteins currently identified in non-mycorrhizal M. truncatula indicated that Cd impaired CO2 assimilation, the mycorrhiza-responsive shoot proteome was characterised by an increase in photosynthesis-related proteins coupled to a reduction in glugoneogenesis/glycolysis and antioxidant processes. By contrast, Cd was found to trigger the opposite response coupled the up-accumulation of molecular chaperones in shoot of mycorrhizal plants relative to those metal-free.

Conclusion

Besides drawing a first picture of shoot proteome modifications upon AM symbiosis and/or heavy metal stress in legume plants, the current work argues for allocation plasticity as the main driving force for Cd extraction in aboveground tissues of M. truncatula upon mycorrhization. Additionally, according to the retrieved proteomic data, we propose that shoots of mycorrhizal legume plants escape Cd toxicity through a metabolic shift implying the glycolysis-mediated mobilization of defence mechanisms at the expense of the photosynthesis-dependent symbiotic sucrose sink.
Mycobacterial infections in a large Virginia hospital, 2001-2009
Authors: Satyanarayana Gowri , Heysell Scott K , Scully Kenneth W , Houpt Eric R
Published: May 2011

Background

In areas where both tuberculosis (TB) and nontuberculous mycobacteria (NTM) are prevalent, descriptive studies of the clinical features of individual mycobacteria are needed to inform clinical triage.

Methods

We queried the University of Virginia Clinical Data Repository for all mycobacterial infections from 2001-2009.

Results

Of 494 mycobacterial infections in 467 patients there were 22 species. Patients with pulmonary Tb were more likely to be reported as immigrants (p < 0.001) and less likely to have a predisposing risk factor for NTM (pre-existing lung disease or host predisposition; p = 0.002). Review of chest CT scans revealed that TB infection was more likely to exhibit cavities and pleural effusion than NTM infection (p < 0.05). Among NTM infections M. kansasii, M. xenopi, and M. fortuitum were more likely than MAC to have cavities. There were at least 83 patients that met criteria for NTM lung disease and these were caused by 9 species. M. abscessus infection was associated with cystic fibrosis and M. xenopi infection was associated with male gender.

Conclusions

In our center mycobacterial infections were common and of diverse species. Immigrant status, cavities, and effusion were associated with TB vs. NTM.
Early detection of secondary damage in ipsilateral thalamus after acute infarction at unilateral corona radiata by diffusion tensor imaging and magnetic resonance spectroscopy
Authors: Li Chuo , Ling Xueying , Liu Sirun , Xu Anding , Zhang Yusheng , Xing Shihui , Pei Zhong , Zeng Jinsheng
Published: May 2011

Background

Traditional magnetic resonance (MR) imaging can identify abnormal changes in ipsilateral thalamus in patients with unilateral middle cerebral artery (MCA) infarcts. However, it is difficult to demonstrate these early changes quantitatively. Diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy (MRS) are potentially sensitive and quantitative methods of detection in examining changes of tissue microstructure and metabolism. In this study, We used both DTI and MRS to examine possible secondary damage of thalamus in patients with corona radiata infarction.

Methods

Twelve patients with unilateral corona radiata infarction underwent MR imaging including DTI and MRS at one week (W1), four weeks (W4), and twelve weeks (W12) after onset of stroke. Twelve age-matched controls were imaged. Mean diffusivity (MD), fractional anisotropy (FA), N-acetylaspartate (NAA), choline(Cho), and creatine(Cr) were measured in thalami.

Results

T1-weighted fluid attenuation inversion recovery (FLAIR), T2-weighted, and T2-FLAIR imaging showed an infarct at unilateral corona radiate but no other lesion in each patient brain. In patients, MD was significantly increased at W12, compared to W1 and W4 (all P< 0.05). NAA was significantly decreased at W4 compared to W1, and at W12 compared to W4 (all P< 0.05) in the ipsilateral thalamus. There was no significant change in FA, Cho, or Cr in the ipsilateral thalamus from W1 to W12. Spearman's rank correlation analysis revealed a significant negative correlation between MD and the peak area of NAA, Cho, and Cr at W1, W4, and W12 and a significant positive correlation of FA with NAA at W1.

Conclusions

These findings indicate that DTI and MRS can detect the early changes indicating secondary damage in the ipsilateral thalamus after unilateral corona radiata infarction. MRS may reveal the progressive course of damage in the ipsilateral thalamus over time.
Causes and 3-year-incidence of blindness in Jing-An District, Shanghai, China 2001-2009
Authors: Wu Liangcheng , Sun Xinghuai , Zhou Xingtao , Weng Chenghai
Published: May 2011

Background

Registered data can provide valuable information regarding blindness. The purpose of this study was to evaluate the main causes and 3-year incidence of registered blindness in Jing-An district in Shanghai, China.

Methods

Data from the blindness registry (age, gender and cause of visual disability) were collected and analyzed. The prevalence of blindness for 2003, 2007, 2009 and the 3-year incidence of blindness were calculated.

Results

The reported blindness increased significantly from 113.7 per 100,000 in 2003 to 145.8 per 100,000 in 2006 to 165.9 per 100,000 in 2009 (P < 0.05, P < 0.05, respectively). Age significantly affects prevalence; the odd ratios (OR) were 2.57 in the 30 y - 49 y range (P < 0.001), 7.27 in the 50 y - 69 y range (P < 0.001) and 21.2 in the ≥ 70 y (P < 0.001). The 3-year incidence increased from 32.3 per 100,000 in 2001-2003 to 34.2 per 100,000 in 2004-2006 to 40.8 per 100,000 in 2007-2009. The causes of new blindness registered in 2001-2009 were myopic macular degeneration (19.4%), followed by glaucoma (17.7%), age-related macular degeneration (11.8%), optical nerve atrophy (9.4%), retinitis pigmentosa (8.6%), diabetic retinopathy (7.8%) and corneal opacity (5.8%).

Conclusions

The 3-year incidence and prevalence of registered blindness increased in the past 9 years. The leading causes of new blindness were myopic macular degeneration, glaucoma and age-related macular degeneration. The pattern of causes has changed little in the past 9 years and is different from other locations in China. The pattern is similar to that of Taiwan, Hongkong, and Western countries.
Adolescent fertility and family planning in East Asia and the Pacific: a review of DHS reports
Authors: Kennedy Elissa , Gray Natalie , Azzopardi Peter , Creati Mick
Published: May 2011

Background

Adolescent pregnancy has significant health and socio-economic consequences for women, their families and communities. Efforts to prevent too-early pregnancy rely on accurate information about adolescents' knowledge, behaviours and access to family planning, however available data are limited in some settings. Demographic and Health Survey (DHS) reports are recognised as providing nationally representative data that are accessible to policymakers and programmers. This paper reviews DHS reports for low and lower middle income countries in East Asia and the Pacific to determine what information regarding adolescent fertility and family planning is available, and summarises key findings.

Methods

The most recent DHS reports were sought for the 33 low and lower middle income countries in the East Asia and Pacific region as defined by UNICEF and World Bank. Age-disaggregated data for all indicators relevant to fertility and current use, knowledge and access to family planning information and services were sought to identify accessible information. Reported data were analysed using an Excel database to determine outcomes for adolescents and compare with adult women.

Results

DHS reports were available for eleven countries: Cambodia, Indonesia, Marshall Islands, Nauru, Papua New Guinea, Philippines, Samoa, Solomon Islands, Timor-Leste, Tuvalu and Vietnam. Twenty seven of 40 relevant DHS indicators reported outcomes for adolescent women aged 15-19 years. There were limited data for unmarried adolescents. A significant proportion of women commence sexual activity and childbearing during adolescence in the context of low contraceptive prevalence and high unmet need for contraception. Adolescent women have lower use of contraception, poorer knowledge of family planning and less access to information and services than adult women.

Conclusion

DHS reports provide useful and accessible data, however, they are limited by the failure to report data for unmarried adolescents and report age-disaggregated data for some indicators. Further research is required to better understand the barriers that both married and unmarried adolescents face accessing reproductive health information and services, and their information and service delivery preferences.
A computational model of the hypothalamic - pituitary - gonadal axis in female fathead minnows (Pimephales promelas) exposed to 17α-ethynylestradiol and 17β-trenbolone
Authors: Li Zhenhong , Kroll Kevin J , Jensen Kathleen M , Villeneuve Daniel L , Ankley Gerald T , Brian Jayne V , Sepúlveda María S , Orlando Edward F , Lazorchak James M , Kostich Mitchell , Armstrong Brandon , Denslow Nancy D , Watanabe Karen H
Published: May 2011

Background

Endocrine disrupting chemicals (e.g., estrogens, androgens and their mimics) are known to affect reproduction in fish. 17α-ethynylestradiol is a synthetic estrogen used in birth control pills. 17β-trenbolone is a relatively stable metabolite of trenbolone acetate, a synthetic androgen used as a growth promoter in livestock. Both 17α-ethynylestradiol and 17β-trenbolone have been found in the aquatic environment and affect fish reproduction. In this study, we developed a physiologically-based computational model for female fathead minnows (FHM, Pimephales promelas), a small fish species used in ecotoxicology, to simulate how estrogens (i.e., 17α-ethynylestradiol) or androgens (i.e., 17β-trenbolone) affect reproductive endpoints such as plasma concentrations of steroid hormones (e.g., 17β-estradiol and testosterone) and vitellogenin (a precursor to egg yolk proteins).

Results

Using Markov Chain Monte Carlo simulations, the model was calibrated with data from unexposed, 17α-ethynylestradiol-exposed, and 17β-trenbolone-exposed FHMs. Four Markov chains were simulated, and the chains for each calibrated model parameter (26 in total) converged within 20,000 iterations. With the converged parameter values, we evaluated the model's predictive ability by simulating a variety of independent experimental data. The model predictions agreed with the experimental data well.

Conclusions

The physiologically-based computational model represents the hypothalamic-pituitary-gonadal axis in adult female FHM robustly. The model is useful to estimate how estrogens (e.g., 17α-ethynylestradiol) or androgens (e.g., 17β-trenbolone) affect plasma concentrations of 17β-estradiol, testosterone and vitellogenin, which are important determinants of fecundity in fish.
Extensive epigenetic reprogramming in human somatic tissues between fetus and adult
Authors: Yuen Ryan KC , Neumann Sarah MA , Fok Alexandra K , Peñaherrera Maria S , McFadden Deborah E , Robinson Wendy P , Kobor Michael S
Published: May 2011

Background

Development of human tissue is influenced by a combination of intrinsic biological signals and extrinsic environmental stimuli, both of which are mediated by epigenetic regulation, including DNA methylation. However, little is currently known of the normal acquisition or loss of epigenetic markers during fetal and postnatal development.

Results

The DNA methylation status of over 1000 CpGs located in the regulatory regions of nearly 800 genes was evaluated in five somatic tissues (brain, kidney, lung, muscle and skin) from eight normal second-trimester fetuses. Tissue-specific differentially methylated regions (tDMRs) were identified in 195 such loci. However, comparison with corresponding data from trisomic fetuses (five trisomy 21 and four trisomy 18) revealed relatively few DNA methylation differences associated with trisomy, despite such conditions having a profound effect on development. Of interest, only 17% of the identified fetal tDMRs were found to maintain this same tissue-specific DNA methylation in adult tissues. Furthermore, 10% of the sites analyzed, including sites associated with imprinted genes, had a DNA methylation difference of >40% between fetus and adult. This plasticity of DNA methylation over development was further confirmed by comparison with similar data from embryonic stem cells, with the most altered methylation levels being linked to domains with bivalent histone modifications.

Conclusions

Most fetal tDMRs seem to reflect transient DNA methylation changes during development rather than permanent epigenetic signatures. The extensive tissue-specific and developmental-stage specific nature of DNA methylation will need to be elucidated to identify abnormal patterns of DNA methylation associated with abnormal development or disease.
Deceased donor neutrophil gelatinase-associated lipocalin and delayed graft function after kidney transplantation: a prospective study
Authors: Hollmen Maria E , Kyllönen Lauri E , Inkinen Kaija A , Lalla Martti LT , Merenmies Jussi , Salmela Kaija T
Published: May 2011

Introduction

Expanding the criteria for deceased organ donors increases the risk of delayed graft function (DGF) and complicates kidney transplant outcome. We studied whether donor neutrophil gelatinase-associated lipocalin (NGAL), a novel biomarker for acute kidney injury, could predict DGF after transplantation.

Methods

We included 99 consecutive, deceased donors and their 176 kidney recipients. For NGAL detection, donor serum and urine samples were collected before the donor operation. The samples were analyzed using a commercial enzyme-linked immunosorbent assay kit (serum) and the ARCHITECT method (urine).

Results

Mean donor serum NGAL (S-NGAL) concentration was 218 ng/mL (range 27 to 658, standard deviation (SD) 145.1) and mean donor urine NGAL (U-NGAL) concentration was 18 ng/mL (range 0 to 177, SD 27.1). Donor S-NGAL and U-NGAL concentrations correlated directly with donor plasma creatinine levels and indirectly with estimated glomerular filtration rate (eGFR) calculated using the modification of diet in renal disease equation for glomerular filtration rate. In transplantations with high (greater than the mean) donor U-NGAL concentrations, prolonged DGF lasting longer than 14 days occurred more often than in transplantations with low (less than the mean) U-NGAL concentration (23% vs. 11%, P = 0.028), and 1-year graft survival was worse (90.3% vs. 97.4%, P = 0.048). High U-NGAL concentration was also associated with significantly more histological changes in the donor kidney biopsies than the low U-NGAL concentration. In a multivariate analysis, U-NGAL, expanded criteria donor status and eGFR emerged as independent risk factors for prolonged DGF. U-NGAL concentration failed to predict DGF on the basis of receiver operating characteristic curve analysis.

Conclusions

This first report on S-NGAL and U-NGAL levels in deceased donors shows that donor U-NGAL, but not donor S-NGAL, measurements give added value when evaluating the suitability of a potential deceased kidney donor.
Effects of lowered serotonin transmission on cocaine-induced striatal dopamine response: PET [11C]raclopride study in humans
Authors: Cox Sylvia M. L. , Benkelfat Chawki , Dagher Alain , Delaney J. Scott , Durand France , Kolivakis Theodore , Casey Kevin F. , Leyton Marco
Published: May 2011

Background

Low serotonin transmission is thought to increase susceptibility to a wide range of substance use disorders and impulsive traits.

Aims

To investigate the effects of lowered serotonin on cocaine-induced (1.0 mg/kg cocaine, self-administered intranasally) dopamine responses and drug craving.

Method

In non-dependent cocaine users, serotonin transmission was reduced using the acute tryptophan depletion method. Striatal dopamine responses were measured using positron emission tomography with [11C]raclopride.

Results

Acute tryptophan depletion increased drug craving and striatal dopamine responses to cocaine. These acute tryptophan depletion-induced increases did not occur in the absence of cocaine.

Conclusions

The results suggest that low serotonin transmission can increase dopaminergic and appetitive responses to cocaine. These findings might identify a mechanism by which individuals with low serotonin are at elevated risk for both substance use disorders and comorbid conditions.