886 research outputs found

    Isolation and characterization of native Bacillus thuringiensis strains from Saudi Arabia with enhanced larvicidal toxicity against the mosquito vector Anopheles gambiae (s.l.).

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    BACKGROUND: Worldwide, mosquito vectors are transmitting several etiological agents of important human diseases, including malaria, causing millions of deaths every year. In Saudi Arabia, as elsewhere, vector-control is based mostly on chemical insecticides which may be toxic and cause environmental deprivation. Here, to support the development of bio-pesticide alternatives, a study was conducted to identify native Bacillus thuringiensis (Bt) isolates with improved toxicity against the malaria vector, Anopheles gambiae (s.l.). METHODS: Sixty-eight Bt isolates were obtained from 300 soil and other samples collected from 16 sites across Saudi Arabia. Bt identification was based on morphological characteristics of colonies, shape of parasporal crystals and biochemical profiles. After characterization of their mosquitocidal activity, larvicidal strains were described through 16S ribosomal DNA gene sequencing, cry, cyt and chi genes PCR-amplification profiles, and SDS-PAGE protein analyses. RESULTS: Spherical Bt crystals were predominant amongst the 68 isolates (34%), while irregular, bi-pyramidal and spore-attached crystals were found in 32, 13 and 21% of strains, respectively. LC50 and LC90 bioassays showed that 23/68 isolates were larvicidal, with distinct biochemical activity profiles compared to non-larvicidal Bt strains. Eight larvicidal strains showed larvicidal activity up to 3.4-fold higher (LC50 range: 3.90-7.40 μg/ml) than the reference Bti-H14 strain (LC50 = 13.33 μg/ml). Of these, 6 strains had cry and cyt gene profiles similar to Bti-H14 (cry4Aa, cry4Ba, cry10, cry11, cyt1Aa, cyt1Ab, cyt2Aa). The seventh strain (Bt63) displaying the highest larvicidal activity (LC50 = 3.90 μg/ml) missed the cry4Aa and cyt1Ab genes and had SDS-PAGE protein profiles and spore/crystal sizes distinct from Bti-H14. The eight strain (Bt55) with LC50 of 4.11μg/ml had cry and cyt gene profiles similar to Bti-H14 but gave a chi gene PCR product size of 2027bp. No strains harbouring cry2, cry17 + 27, cry24 + 40, cry25, cry29, cry30, or cyt2Ba were detected. CONCLUSION: This study represents the first report of several Saudi indigenous Bt strains with significantly higher larvicidal efficacy against An. gambiae than the reference Bti-H14 strain. The very high toxicity of the Bt63 strain, combined with distinct cry and cyt genes and SDS-PAGE-protein profiles makes it a promising candidate for future applications in mosquito bio-control

    Reinventing Public Sector for Innovativeness and Performance: A Case Study of University of the Punjab, Lahore

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    Today’s complex and competitive work environment has urged organizations both public and private for revisiting their practices, management styles and attitudes for improved performance. There is a great realization that when an organization adopts innovativeness, creativity and sate of the art practices in all of its dimensions, it becomes successful. Literature on this subject also reveals that public sector organizations universally suffer from bureaucratic behaviors, centralized systems and rigid practices and therefore, needs more of such innovativeness through reinventing their existing ways, behaviors and systems (Moghaddam et al., 2015, Osborne and Gaebler 1992). This study towards its attempt towards reinventing the public sector organization aims to access how organizational innovativeness impacts the performance using University of the Punjab as a case in point. The study sample consisted of 50 head of departments. The study used a modified instrument that measures both innovative orientation, which is based on the extensively tested Covin and Slevin (1989) scale and innovation management, which is based on Stevenson’s (1983) conceptualization of innovation as a set of opportunity-based management practices. Performance is multi-dimensional in nature; therefore, both financial and non-financial performance indicators have been used. Relationships between these constructs have been analyzed through PLS-SEM (Partial Least Square Structural Equation Modeling). The results demonstrate that a greater strategic orientation and better reward philosophy positively influence organizational performance and satisfaction. Limited evidence was found about the direct relationship between innovative orientation and financial performance. The results indicate that there is limited innovative orientation and innovation management in University of the Punjab which has theoretical and practical implications. The study offers recommendations for reinventing public sector through bringing in innovativeness, efficiency and agility towards improved organizational performance

    Oral Class I and III antiarrhythmic drugs for maintaining sinus rhythm after catheter ablation of atrial fibrillation

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    This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects of oral Class I and III antiarrhythmic drugs for maintaining sinus rhythm in patients undergoing catheter ablation, compared to catheter ablation alone, for atrial fibrillation (AF)

    Superficial Ulnar Artery with High Bifurcation of the Brachial Artery and its Clinical Significance

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    Although the variations in brachial artery branching patterns are commonly observed, only 3.75% exhibit a high ulnar artery variation1. An even fewer number present with a bilateral superficial ulnar artery, as was reported by Fadel and Amonoo-Kuofi2. The compounding variations of a high bifurcation of the brachial artery and a superficial ulnar artery may be asymptomatic, but demonstrate important clinical significance in relation to accidental intra-arterial injections, errors in blood pressure readings, as well as orthopedic, plastic and vascular surgeries of the upper limbs1. This study aims to expand upon previous literature and provide additional insight to the field of clinical anatomy, while educating physicians of the possible presentations and potentially severe risks associated with these variations

    A survey of statistics in three UK general practice journal

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    Background Many medical specialities have reviewed the statistical content of their journals. To our knowledge this has not been done in general practice. Given the main role of a general practitioner as a diagnostician we thought it would be of interest to see whether the statistical methods reported reflect the diagnostic process. Methods Hand search of three UK journals of general practice namely the British Medical Journal (general practice section), British Journal of General Practice and Family Practice over a one-year period (1 January to 31 December 2000). Results A wide variety of statistical techniques were used. The most common methods included t-tests and Chi-squared tests. There were few articles reporting likelihood ratios and other useful diagnostic methods. There was evidence that the journals with the more thorough statistical review process reported a more complex and wider variety of statistical techniques. Conclusions The BMJ had a wider range and greater diversity of statistical methods than the other two journals. However, in all three journals there was a dearth of papers reflecting the diagnostic process. Across all three journals there were relatively few papers describing randomised controlled trials thus recognising the difficulty of implementing this design in general practice

    Protocol for the adolescent hayfever trial: cluster randomised controlled trial of an educational intervention for healthcare professionals for the management of school-age children with hayfever

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    <p>Abstract</p> <p>Background</p> <p>Seasonal allergic rhinitis (hayfever) is common and can contribute to a considerable reduction in the quality of life of adolescents. This study aims to examine the effectiveness of standardised allergy training for healthcare professionals in improving disease-specific quality of life in adolescents with hayfever.</p> <p>Methods/Design</p> <p>Adolescents with a history of hayfever registered in general practices in Scotland and England were invited to participate in a cluster randomised controlled trial. The unit of randomisation is general practices.</p> <p>The educational intervention for healthcare professionals consists of a short standardised educational course, which focuses on the management of allergic rhinitis. Patients in the intervention arm of this cluster randomised controlled trial will have a clinic appointment with their healthcare professional who has attended the training course. Patients in the control arm will have a clinic appointment with their healthcare professional and will receive usual care.</p> <p>The primary outcome measure is the change in the Rhinoconjunctivitis Quality of Life Questionnaire with Standardised Activities (RQLQ(S)) score between baseline and six weeks post-intervention in the patient intervention and control groups.</p> <p>Secondary outcome measures relate to healthcare professionals' understanding and confidence in managing allergic rhinitis, changes in clinical practice, numbers of consultations for hayfever and adolescent exam performance.</p> <p>A minimum of 11 practices in each arm of the trial (10 patients per cluster) will provide at least 80% power to demonstrate a minimal clinically important difference of 0.5 in RQLQ(S) score at a significance level of 5% based on an Intraclass Correlation Coefficient (ICC) of 0.02.</p> <p>Discussion</p> <p>At the time of submission, 24 general practices have been recruited (12 in each arm of the trial) and the interventions have been delivered. Follow-up data collection is complete. 230 children consented to take part in the trial; however complete primary outcome data are only available for 160. Further recruitment of general practices and patients will therefore take place in the summer of 2010.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN95538067</p

    Effects of air pollution and the introduction of the London Low Emission Zone on the prevalence of respiratory and allergic symptoms in schoolchildren in East London: a sequential cross-sectional study

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    The adverse effects of traffic-related air pollution on children’s respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8–9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00–1.02), NO2 (1.03, 1.00–1.06), PM10 (1.16, 1.04–1.28) and PM2.5 (1.38, 1.08–1.78), all per μg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions

    Involvement of bcl-2 and p21waf1 proteins in response of human breast cancer cell clones to Tomudex

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    Mechanisms of resistance to Tomudex include increased thymidylate synthase activity, as well as reduced intracellular drug uptake and polyglutamation. However, little is known about other mechanisms of resistance, such as a possible protection against Tomudex-induced apoptosis mediated by bcl-2. We transfected the MDA-MB-435 human breast cancer cell line, which is characterized by a mutated p53 gene, with cDNA of the bcl-2 gene and generated two clones (MDA-bcl4 and MDA-bcl7) characterized by bcl-2 expression twofold and fourfold that observed in the control cell clone (MDAneo). A concomitant overexpression of p21wafl was also detected in the MDA-bcl7 clone. The MDA-bcl4 clone was three times more resistant to a 24-h Tomudex exposure than the MDAneo clone, whereas the MDA-bcl7 clone was as sensitive to Tomudex as the control cell clone. A lower sensitivity of the MDA-bcl4 clone than MDAneo and MDA-bcl7 clones to 5-fluorouracil and gemcitabine was also observed. No significant difference was noted in the susceptibility of clones to fludarabine and methothrexate. Basal levels of thymidylate synthase activity were superimposable in the three clones. Tomudex induced a marked accumulation of cells in the S phase in all the clones. However, an apoptotic hypodiploid DNA peak and the characteristic nuclear morphology of apoptosis were observed only in the MDA-bcl7 clone after exposure to Tomudex. No difference in the treatment-induced modulation of proteins involved in cell cycle progression (cyclin A, cdk2, pRB, E2F-1) and apoptosis (bcl-2, bax) was observed in the three clones. The only exception was that the expression of p21wafl in the MDA-bcl4 clone was inducible at a Tomudex concentration much higher than that required to induce the protein in the other clones. Overall, the results indicate that bcl-2 and p21wafl proteins concur in determining the cellular profile of sensitivity/resistance to Tomudex. © 1999 Cancer Research Campaig

    Decommissioning care: The need for rigorous multifaceted evaluations of decisions to withdraw health services

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    In this Perspective on the two clinical trials of Terry Haines and colleagues that incrementally removed and reinstated allied healthcare services, Aziz Sheikh discusses the evidence base for the routine provision of such services
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