Changes in left atrial deformation in hypertrophic cardiomyopathy: Evaluation by vector velocity imaging.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. We assessed the global and regional left atrial (LA) function and its relation to left ventricular (LV) mechanics and clinical status in patients with HCM using Vector Velocity Imaging (VVI). METHODS: VVI of the LA and LV was acquired from apical four- and two-chamber views of 108 HCM patients (age 40 ± 19years, 56.5% men) and 33 healthy subjects, all had normal LV systolic function. The LA subendocardium was traced to obtain atrial volumes, ejection fraction, velocities, and strain (ϵ)/strain rate (SR) measurements. RESULTS: Left atrial reservoir (ϵsys,SRsys) and conduit (early diastolic SRe) function were significantly reduced in HCM compared to controls (P  - 1.8s(- 1) was 81% sensitive and 30% specific, SRa> - 1.5s(- 1) was 73% sensitive and 40% specific. By multivariate analysis global LVϵsys and LV septal thickness are independent predictors for LAϵsys, while end systolic diameter is the only independent predictor for SRsys, P < .001. CONCLUSION: Left atrial reservoir and conduit function as measured by VVI were significantly impaired while contractile function was preserved among HCM patients. Left atrial deformation was greatly influenced by LV mechanics and correlated to severity of phenotype

Sharing the transformation: Public relations and the uae come of age

© 2009 Taylor and Francis. Much like the country itself, the practice of public relations in the United Arab Emirates (UAE) has undergone a profound evolution during its short history of 30 years. As the country has grown, so too has the practice of public relations. Once no agencies existed, but today global multinational public relations firms have established a presence in the UAE, some with an equity relationship with their local partners, some as fully owned branches of global firms based in the United States or Europe, and others through affiliates. Companies like Team: Young and Rubicam, Gulf Hill and Knowlton, and Burston-Marsteller operate alongside local, smaller companies, competing for the same dollars and dirhams

MicroRNAs in Cardiac Hypertrophy

Like other organs, the heart undergoes normal adaptive remodeling, such as cardiac hypertrophy, with age. This remodeling, however, is intensified under stress and pathological conditions. Cardiac remodeling could be beneficial for a short period of time, to maintain a normal cardiac output in times of need; however, chronic cardiac hypertrophy may lead to heart failure and death. MicroRNAs (miRNAs) are known to have a role in the regulation of cardiac hypertrophy. This paper reviews recent advances in the field of miRNAs and cardiac hypertrophy, highlighting the latest findings for targeted genes and involved signaling pathways. By targeting pro-hypertrophic genes and signaling pathways, some of these miRNAs alleviate cardiac hypertrophy, while others enhance it. Therefore, miRNAs represent very promising potential pharmacotherapeutic targets for the management and treatment of cardiac hypertrophy. - 2019 by the authors. Licensee MDPI, Basel, Switzerland

A pilot course for training-in-context in statistics and research methods: Radiation oncology

Objectives. Inadequate training of investigators in statistics and research methods in Africa contributes to having limited local evidence and infrastructure to support multi-centre international trials. Methods of teaching junior oncology professionals tend not to emphasise research discovery, or the roles of emotional engagement and social networking in facilitating effective and efficient learning. We developed a strategy for teaching research methods and statistics in-context, centred on a shared international and practical research project. Design. An African research network (AFRES) was created and members conducted a pilot clinical registry study to acquire real-time data over a 4-month period in 2011. Following study closure, a proto-course consisting of 7 modules, each orientated to a practical topic in study development, implementation and reporting was administered over 18 weeks to all eight AFRES members. A survey of participants was conducted to evaluate the impact of this training strategy. Results. This strictly voluntary project had 5 of 8 AFRES members engaged in the process. Within one year, we generated and submitted two manuscripts and two news items for publication. Participants reported an increased understanding of the principles of evidence-based practice, research methods and interest in pursuing future research initiatives.Conclusion. A novel strategy to build international research infrastructure in Africa, grounded in a practical and relevant project, and which is collaborative and engaging, appears to be efficient and effective

Clostridium difficile : Infection, diagnosis and treatment with antimicrobial drugs : A review article

Clostridium difï¬cile infection (CDI) is increasing problem in healthcare, associated with high incidence, mortality, and costs in hospitalized patients.  Dramatic increases in the incidence and severity of healthcare-associated C. difficile infection have occurred since the last decade, including elderly population, young adults, pregnant females, infants and children. C. difï¬cile infections are mainly linked to the prolonged use of wide-spectrum antibiotics that disrupt the intestinal microbiota equilibrium. Toxigenic strains of C. difï¬cile commonly produce two clostridial toxins, toxins A (TcdA) and B (TcdB), to which disease symptoms are attributed. Few strains of C. difï¬cile may also produce another more powerful binary toxin associated with high fatality. The clinical manifestations of infection with toxin-producing strains of C. difï¬cile range from symptomless carriage, to mild or moderate watery-bloody diarrhea, and few percentage developed fulminant and sometimes fatal pseudomembranous colitis. Complications that have been associated with CDI include dehydration, electrolyte disturbances, toxic megacolon, bowel perforation, hypotension, renal failure, systemic inflammatory response syndrome, sepsis, and death. The most important step in treating CDI is immediately discontinuing use of offending antimicrobial drug. Both metronidazole and vancomycin are equally effective for the treatment of mild CDI, but vancomycin is superior for treating patients with severe C. difï¬cile disease. Recently, fidaxomicin proved to be superior to other drugs in treatment of patients who are at high risk for CDI relapse.Â

Density functional theory study on the catalytic dehydrogenation of methane on MoO3 (010) surface

Methane conversion offers hydrocarbon building blocks of high market value, which are easier to transport than natural gas. Under non-oxidative conditions, the process can also produce clean hydrogen fuel. In this study, we explored the catalytic dehydrogenation of methane on molybdenum oxide (MoO3) surface. Periodic density functional theory calculations were performed to study the adsorption of CH4 on two different supercells of the MoO3 (010) surface. It was found that CH4 adsorption was more favorable on a smooth surface constructed of Mo and O network, rather than a surface made with dangling O atoms as thought before. A reaction mechanism for hydrogen formation was then proposed. The first energy barrier for the H-abstraction step was calculated to be 66.4 kJ/mol, which is lower than previously reported values obtained for simple MoxOy clusters. The reactions were discussed using the two-state reactivity approach, where different electronic states can play a role in the H-abstraction step. The mechanism also showed the formation of methyl radicals and ethylene, in addition to molecular hydrogen.This research is funded by Qatar University’s grant number QUCG-CAS-21221

Investigating the association between obesity and asthma in 6- to 8-year-old Saudi children:a matched case-control study

Background: Previous studies have demonstrated an association between obesity and asthma, but there remains considerable uncertainty about whether this reflects an underlying causal relationship. Aims: To investigate the association between obesity and asthma in pre-pubertal children and to investigate the roles of airway obstruction and atopy as possible causal mechanisms. Methods: We conducted an age- and sex-matched case–control study of 1,264 6- to 8-year-old schoolchildren with and without asthma recruited from 37 randomly selected schools in Madinah, Saudi Arabia. The body mass index (BMI), waist circumference and skin fold thickness of the 632 children with asthma were compared with those of the 632 control children without asthma. Associations between obesity and asthma, adjusted for other potential risk factors, were assessed separately in boys and girls using conditional logistic regression analysis. The possible mediating roles of atopy and airway obstruction were studied by investigating the impact of incorporating data on sensitisation to common aeroallergens and measurements of lung function. Results: BMI was associated with asthma in boys (odds ratio (OR)=1.14, 95% confidence interval (CI), 1.08–1.20; adjusted OR=1.11, 95% CI, 1.03–1.19) and girls (OR=1.37, 95% CI, 1.26–1.50; adjusted OR=1.38, 95% CI, 1.23–1.56). Adjusting for forced expiratory volume in 1 s had a negligible impact on these associations, but these were attenuated following adjustment for allergic sensitisation, particularly in girls (girls: OR=1.25; 95% CI, 0.96–1.60; boys: OR=1.09, 95% CI, 0.99–1.19). Conclusions: BMI is associated with asthma in pre-pubertal Saudi boys and girls; this effect does not appear to be mediated through respiratory obstruction, but in girls this may at least partially be mediated through increased risk of allergic sensitisation

Reaction mechanisms in the 6Li+59Co system

The reactions induced by the weakly bound 6Li projectile interacting with the intermediate mass target 59Co were investigated. Light charged particles singles and $\alpha$-$d$ coincidence measurements were performed at the near barrier energies E_lab = 17.4, 21.5, 25.5 and 29.6 MeV. The main contributions of the different competing mechanisms are discussed. A statistical model analysis, Continuum-Discretized Coupled-Channels calculations and two-body kinematics were used as tools to provide information to disentangle the main components of these mechanisms. A significant contribution of the direct breakup was observed through the difference between the experimental sequential breakup cross section and the CDCC prediction for the non-capture breakup cross section.Comment: 30 pages, 8 figure

Detection of the BL Lac Object H1426+428 at TeV Gamma Ray Energies

A very high energy (VHE) gamma-ray signal has been detected at the 5.4 sigma level from H1426+428, an x-ray selected BL Lacertae object at a redshift of 0.129. The object was monitored from 1995 - 1998 with the Whipple 10m imaging atmospheric Cherenkov telescope as part of a general blazar survey; the results of these observations, although not statistically significant, were consistently positive. X-ray observations of H1426+428 during 1999 with the BeppoSAX instrument revealed that the peak of its synchrotron spectrum occurs at > 100 keV, leading to the prediction of observable TeV emission from this object. H1426+428 was monitored extensively at the Whipple Observatory during the 1999, 2000, and 2001 observing seasons. The strongest TeV signals were detected in 2000 and 2001. During 2001, an integral flux of 2.04 +/- 0.35 x10e-11 cm-2 s-1 above 280 GeV was recorded from H1426+428. The detection of H1426+428 supports the idea that, as also seen in Markarian 501 and 1ES2344+514, BL Lacertae objects with extremely high synchrotron peak frequencies produce gamma rays in the TeV range.Comment: 35 pages, 7 figures, accepted by ApJ Two upper limits in Table 3 (upper limits for 1995 and 1997) are different from the ApJ versio