1,119 research outputs found
Spongionella secondary metabolites protect mitochondrial function in cortical neurons against oxidative stress
Accepted: 8 January 2014 This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Acknowledgments The research leading to these results has received funding from the following FEDER cofunded-grants: From Ministerio de Ciencia y Tecnología, Spain: AGL2009-13581-CO2-01, AGL2012-40485-CO2-01. From Xunta de Galicia, Spain: 10PXIB261254 PR. From the European Union’s Seventh Framework Programme managed by REA—Research Executive Agency (FP7/2007–2013) under grant agreement Nos. 265896 BAMMBO, 265409 µAQUA, and 262649 BEADS, 315285 CIGUATOOLS and 312184 PHARMASEA. From the Atlantic Area Programme (Interreg IVB Trans-national): 2009-1/117 Pharmatlantic. MER thanks the Government of the Arab Republic of Egypt for a PhD Scholarship. MJ thanks the Scottish University Life Science Alliance which provided funding to set up the compound library.Peer reviewedPublisher PD
A systematic review of ICD complications in randomised controlled trials versus registries: is our 'real-world' data an underestimation?
Implantable cardioverter defibrillator (ICD) implantation carries a significant risk of complications, however published estimates appear inconsistent. We aimed to present a contemporary systematic review using meta-analysis methods of ICD complications in randomised controlled trials (RCTs) and compare it to recent data from the largest international ICD registry, the US National Cardiovascular Data Registry (NCDR). PubMed was searched for any RCTs involving ICD implantation published 1999-2013; 18 were identified for analysis including 6433 patients, mean follow-up 3 months-5.6 years. Exclusion criteria were studies of children, hypertrophic cardiomyopathy, congenital heart disease, resynchronisation therapy and generator changes. Total pooled complication rate from the RCTs (excluding inappropriate shocks) was 9.1%, including displacement 3.1%, pneumothorax 1.1% and haematoma 1.2%. Infection rate was 1.5%.There were no predictors of complications but longer follow-up showed a trend to higher complication rates (p=0.07). In contrast, data from the NCDR ICD, reporting on 356 515 implants (2006-2010) showed a statistically significant threefold lower total major complication rate of 3.08% with lead displacement 1.02%, haematoma 0.86% and pneumothorax 0.44%. The overall ICD complication rate in our meta-analysis is 9.1% over 16 months. The ICD complication reported in the NCDR ICD registry is significantly lower despite a similar population. This may reflect under-reporting of complications in registries. Reporting of ICD complications in RCTs and registries is very variable and there is a need to standardise classification of complications internationally
Priabonian Sharks and Rays (Late Eocene: Neoselachii) From Minqar Tabaghbagh In The Western Qattara Depression, Egypt
http://deepblue.lib.umich.edu/bitstream/2027.42/90948/1/Contributions32no06-c04-30-2012.pd
Climate change promotes parasitism in a coral symbiosis.
Coastal oceans are increasingly eutrophic, warm and acidic through the addition of anthropogenic nitrogen and carbon, respectively. Among the most sensitive taxa to these changes are scleractinian corals, which engineer the most biodiverse ecosystems on Earth. Corals' sensitivity is a consequence of their evolutionary investment in symbiosis with the dinoflagellate alga, Symbiodinium. Together, the coral holobiont has dominated oligotrophic tropical marine habitats. However, warming destabilizes this association and reduces coral fitness. It has been theorized that, when reefs become warm and eutrophic, mutualistic Symbiodinium sequester more resources for their own growth, thus parasitizing their hosts of nutrition. Here, we tested the hypothesis that sub-bleaching temperature and excess nitrogen promotes symbiont parasitism by measuring respiration (costs) and the assimilation and translocation of both carbon (energy) and nitrogen (growth; both benefits) within Orbicella faveolata hosting one of two Symbiodinium phylotypes using a dual stable isotope tracer incubation at ambient (26 °C) and sub-bleaching (31 °C) temperatures under elevated nitrate. Warming to 31 °C reduced holobiont net primary productivity (NPP) by 60% due to increased respiration which decreased host %carbon by 15% with no apparent cost to the symbiont. Concurrently, Symbiodinium carbon and nitrogen assimilation increased by 14 and 32%, respectively while increasing their mitotic index by 15%, whereas hosts did not gain a proportional increase in translocated photosynthates. We conclude that the disparity in benefits and costs to both partners is evidence of symbiont parasitism in the coral symbiosis and has major implications for the resilience of coral reefs under threat of global change
Cytotoxicity of nickel zinc ferrite nanoparticles on cancer cells of epithelial origin
In this study, in vitro cytotoxicity of nickel zinc (NiZn) ferrite nanoparticles against human colon cancer HT29, breast cancer MCF7, and liver cancer HepG2 cells was examined. The morphology, homogeneity, and elemental composition of NiZn ferrite nanoparticles were investigated by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The exposure of cancer cells to NiZn ferrite nano-particles (15.6-1,000 μg/mL; 72 hours) has resulted in a dose-dependent inhibition of cell growth determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The quantification of caspase-3 and -9 activities and DNA fragmentation to assess the cell death pathway of the treated cells showed that both were stimulated when exposed to NiZn ferrite nanoparticles. Light microscopy examination of the cells exposed to NiZn ferrite nanoparticles demonstrated significant changes in cellular morphology. The HepG2 cells were most prone to apoptosis among the three cells lines examined, as the result of treatment with NiZn nanoparticles. In conclusion, NiZn ferrite nanoparticles are suggested to have potential cytotoxicity against cancer cells
Internet-based search of randomised trials relevant to mental health originating in the Arab world
BACKGROUND:
The internet is becoming a widely used source of accessing medical research through various on-line databases. This instant access to information is of benefit to busy clinicians and service users around the world. The population of the Arab World is comparable to that of the United States, yet it is widely believed to have a greatly contrasting output of randomised controlled trials related to mental health. This study was designed to investigate the existence of such research in the Arab World and also to investigate the availability of this research on-line.
METHODS:
Survey of findings from three internet-based potential sources of randomised trials originating from the Arab world and relevant to mental health care.
RESULTS:
A manual search of an Arabic online current contents service identified 3 studies, MEDLINE, EMBASE, and PsycINFO searches identified only 1 study, and a manual search of a specifically indexed, study-based mental health database, PsiTri, revealed 27 trials.
CONCLUSION:
There genuinely seem to be few trials from the Arab world and accessing these on-line was problematic. Replication of some studies that guide psychiatric/psychological practice in the Arab world would seem prudent
Environmental, maternal, and reproductive risk factors for childhood acute lymphoblastic leukemia in Egypt : a case-control study
BACKGROUND\ud
Acute lymphocytic leukemia (ALL) is the most common pediatric cancer. The exact cause is not known in most cases, but past epidemiological research has suggested a number of potential risk factors. This study evaluated associations between environmental and parental factors and the risk for ALL in Egyptian children to gain insight into risk factors in this developing country.\ud
METHODS\ud
We conducted a case-control design from May 2009 to February 2012. Cases were recruited from Children's Cancer Hospital, Egypt (CCHE). Healthy controls were randomly selected from the general population to frequency-match the cumulative group of cases by sex, age groups (<1; 1 - 5; >5 - 10; >10 years) and region of residence (Cairo metropolitan region, Nile Delta region (North), and Upper Egypt (South)). Mothers provided answers to an administered questionnaire about their environmental exposures and health history including those of the father. Odds ratios (ORs) and 95 % confidence intervals (CI) were calculated using logistic regression with adjustment for covariates.\ud
RESULTS\ud
Two hundred ninety-nine ALL cases and 351 population-based controls frequency-matched for age group, gender and location were recruited. The risk of ALL was increased with the mother's use of medications for ovulation induction (ORadj = 2.5, 95 % CI =1.2 -5.1) and to a lesser extend with her age (ORadj = 1.8, 95 % CI = 1.1 - 2.8, for mothers ≥ 30 years old). Delivering the child by Cesarean section, was also associated with increased risk (ORadj = 2.01, 95 % CI =1.24-2.81).\ud
CONCLUSIONS\ud
In Egypt, the risk for childhood ALL appears to be associated with older maternal age, and certain maternal reproductive factors
Analysis of the filed data of a sample of Egyptian children with bronchial asthma
Background: Identification of the clinical profile of asthma in a community is crucial to the understanding of the growing disease burden. We sought to evaluate the clinical characteristics and management outcome of a sample of asthmatic children from Cairo city and its suburbs. Methods: This retrospective study analyzed the data of 422 consecutively numbered files of asthmatic children from the Pediatric Allergy and Immunology Unit of Ain Shams University Children's Hospital. Data collected included the age at onset, duration of follow up, precipitating factors, feeding history, clinical severity, presence of other allergic diseases and outcome and course of the disease. This is besides the available results of laboratory and imaging studies and the treatment received including the routes and types of therapy. Results: The results revealed that 197 children (46.7%) had bronchial asthma only while 225 (53.3%) had concomitant allergic disorders. Males outnumbered females and urban residents outnumbered suburban and rural residents and all cases belonged to the low and middle social and economic community sectors. A positive family history of allergy in general was evident in about 40% of cases. Viral infection was the most common precipitating factor for exacerbations. Mild and moderate persistent asthma were more frequent than the severe variety (15.10%, 10.20%, and 1.50%). Serum total IgE and peripheral blood eosinophil counts were elevated and atopy was evident in most cases. Inhaled corticosteroid therapy was the most commonly prescribed treatment in the current study but compliance was generally poor. Conclusion: Wider scale multi-center studies in Cairo and other localities of Egypt are needed to outline the profile of childhood asthma in the whole country using a population rather than a referral center-based approach.Keywords: Pediatric asthma, risk factors, asthma grade, asthma triggers, smoking, residenceEgypt J Pediatr Allergy Immunol 2009;7(2):59-6
Synthesis and propagation of complement C3 by microglia/monocytes in the aging retina
INTRODUCTION Complement activation is thought to contribute to the pathogenesis of age-related macular degeneration (AMD), which may be mediated in part by para-inflammatory processes. We aimed to investigate the expression and localization of C3, a crucial component of the complement system, in the retina during the course of aging. METHODS SD rats were born and reared in low-light conditions, and euthanized at post-natal (P) days 100, 450, or 750. Expression of C3, IBA1, and Ccl- and Cxcl- chemokines was assessed by qPCR, and in situ hybridization. Thickness of the ONL was assessed in retinal sections as a measure of photoreceptor loss, and counts were made of C3-expressing monocytes. RESULTS C3 expression increased significantly at P750, and correlated with thinning of the ONL, at P750, and up-regulation of GFAP. In situ hybridization showed that C3 was expressed by microglia/monocytes, mainly from within the retinal vasculature, and occasionally the ONL. The number of C3-expressing microglia increased significantly by P750, and coincided spatiotemporally with thinning of the ONL, and up-regulation of Ccl- and Cxcl- chemokines. CONCLUSIONS Our data suggest that recruited microglia/monocytes contribute to activation of complement in the aging retina, through local expression of C3 mRNA. C3 expression coincides with age-related thinning of the ONL at P750, although it is unclear whether the C3-expressing monocytes are a cause or consequence. These findings provide evidence of activation of complement during natural aging, and may have relevance to cellular events underling the pathogenesis of age-related retinal diseases.Funding provided by Australian Research Council Centres of Excellence Program Grant (CE0561903)
Novel resonant and light-guiding phenomena in photonics
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 100-109).We investigate theoretically five novel resonant and light-guiding photonics phenomena. First, we develop a universal coupled mode theory (CMT) treatment of the freespace scattering of waves from resonant objects. This analytical framework very accurately models the scattering and absorption cross sections, as long as the resonant scatterer has spherical/cylindrical symmetry, or is sufficiently smaller than the resonant wavelength of the incident wave. We apply it to study the scattering of light from spherically symmetrical resonant objects and atoms, and also the neutron scattering off nuclei. Then, we propose an efficient weakly-radiative Wireless Energy Transfer (WET) scheme between two identical classical resonant objects, strongly coupled to an intermediate one having the same resonance frequency. The transfer mechanism, analyzed by CMT, relies on the adiabatic evolution of a dark eigenstate of the 3-object system. We explore its performance in various parameter regimes, and illustrate it by witricity-type WET between resonant inductively-coupled capacitively-loaded metallic loops. Third, we develop an analytical CMT model for the electric field generated by an arbitrary polarization source in a general photonic structure (that could involve loss, gain and/or nonlinearities). Based on this model, we investigate the criteria for enhancing the efficiency of nonlinear effects, and produce efficient terahertz sources. The results, validated by Finite-Difference Time-Domain (FDTD) calculations, suggest that this approach could potentially be a substitute for the more numerically intensive FDTD method. Next, we propose a 2D PhC structure that supports super-collimation over a large frequency range. We theoretically and numerically investigate the collimation mechanism in this 2D structure, in comparison to that of two other frequently used related PhC structures. We also point out the potential importance of this structure in designing super-collimation-based devices for monochromatic and polychromatic light. Finally, we present numerical simulations of anisotropic multilayers that strongly discriminate certain incidence angles of light, over a broad range of frequencies and irrespective of polarization. Such systems could improve the efficiency of solar cells.by Rafif E. Hamam.Ph.D
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