618 research outputs found

    Impact of Community-Based Larviciding on the Prevalence of Malaria Infection in Dar es Salaam, Tanzania.

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    The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success. Larviciding, in particular, could be effective in urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings. The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infection in Dar es Salaam, United Republic of Tanzania. Larviciding was implemented in 3 out of 15 targeted wards of Dar es Salaam in 2006 after two years of baseline data collection. This intervention was subsequently scaled up to 9 wards a year later, and to all 15 targeted wards in 2008. Continuous randomized cluster sampling of malaria prevalence and socio-demographic characteristics was carried out during 6 survey rounds (2004-2008), which included both cross-sectional and longitudinal data (N = 64,537). Bayesian random effects logistic regression models were used to quantify the effect of the intervention on malaria prevalence at the individual level. Effect size estimates suggest a significant protective effect of the larviciding intervention. After adjustment for confounders, the odds of individuals living in areas treated with larviciding being infected with malaria were 21% lower (Odds Ratio = 0.79; 95% Credible Intervals: 0.66-0.93) than those who lived in areas not treated. The larviciding intervention was most effective during dry seasons and had synergistic effects with other protective measures such as use of insecticide-treated bed nets and house proofing (i.e., complete ceiling or window screens). A large-scale community-based larviciding intervention significantly reduced the prevalence of malaria infection in urban Dar es Salaam

    Magnetically responsive microbubbles as delivery vehicles for targeted sonodynamic and antimetabolite therapy of pancreatic cancer

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    Magnetically responsive microbubbles (MagMBs), consisting of an oxygen gas core and a phospholipid coating functionalised with Rose Bengal (RB) and/or 5-fluorouracil (5-FU), were assessed as a delivery vehicle for the targeted treatment of pancreatic cancer using combined antimetabolite and sonodynamic therapy (SDT). MagMBs delivering the combined 5-FU/SDT treatment produced a reduction in cell viability of over 50% when tested against a panel of four pancreatic cancer cell lines in vitro. Intravenous administration of the MagMBs to mice bearing orthotopic human xenograft BxPC-3 tumours yielded a 48.3% reduction in tumour volume relative to an untreated control group (p<0.05) when the tumour was exposed to both external magnetic and ultrasound fields during administration of the MagMBs. In contrast, application of an external ultrasound field alone resulted in a 27% reduction in tumour volume. In addition, activated caspase and BAX protein levels were both observed to be significantly elevated in tumours harvested from animals treated with the MagMBs in the presence of magnetic and ultrasonic fields when compared to expression of those proteins in tumours from either the control or ultrasound field only groups (p<0.05). These results suggest MagMBs have considerable potential as a platform to enable the targeted delivery of combined sonodynamic/antimetabolite therapy in pancreatic cancer

    Outcome after failure of allogeneic hematopoietic stem cell transplantation in children with acute leukemia: a study by the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC)

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    Allogeneic hematopoietic stem cell transplantation (SCT) contributes to improved outcome in childhood acute leukemia (AL). However, therapeutic options are poorly defined in case of post-transplantation relapse. We aimed to compare treatment strategies in 334 consecutive children with acute leukemia relapse or progression after SCT in a recent ten-year period. Data could be analyzed in 288 patients (157 ALL, 123 AML and 8 biphenotypic AL) with a median age of 8.16 years at transplantation. The median delay from first SCT to relapse or progression was 182 days. The treatment consisted in chemotherapy alone (n=108), chemotherapy followed by second SCT (n=70), supportive/palliative care (n=67), combination of chemotherapy and DLI (n=30), or isolated reinfusion of donor lymphocytes (DLI) (n=13). The median OS duration after relapse was 164 days and differed according to therapy: DLI after chemotherapy = 385 d, second allograft = 391d, chemotherapy = 174d, DLI alone = 140d, palliative care = 43d. A second SCT or a combination of chemotherapy and donor lymphocytes infusion yielded similar outcome (HR=0.85, p=0.53) unlike chemotherapy alone (HR 1.43 p=0.04), palliative care (HR=4.24, p<0.0001) or isolated DLI (HR=1,94, p<0.04). Despite limitations in this retrospective setting, strategies including immunointervention appear superior to other approaches, mostly in AML

    Molecular organization in the twist–bend nematic phase by resonant X-ray scattering at the Se K-edge and by SAXS, WAXS and GIXRD

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    Using a magnetically aligned liquid crystal mixture containing a novel Se-labelled dimer and the difluoroterphenyl dimer DTC5C7, the twist–bend nematic phase (Ntb) was studied by the resonant scattering of hard X-rays and by conventional small and wide-angle X-ray scattering (SAXS, WAXS). Resonant diffraction spots indicated a helix with a 9–12 nm pitch in the Ntb phase and an unprecedentedly high helix orientation. This enabled deconvolution of global and local order parameters. These findings, combined with the simultaneously recorded resonant and non-resonant SAXS and WAXS data, allowed us to construct a locally layered molecular model of the Ntb phase, where the average twisted conformation of each molecule was idealised as a helical segment, matching the local heliconical director field. The dimers were found to be less bent in the Ntb phase than in their minimum energy conformation, and straightening further with increasing temperature. It is proposed that on further heating their low bend angle allows the transition to the normal nematic phase, where the molecules can freely move longitudinally, without the need to perform screw-like motion as in the Ntb phase. At the low-temperature end, the increasing molecular twist becomes unsustainable, leading to a transition to a smectic phase, where no twist is required

    Ionic liquids at electrified interfaces

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    Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

    Biomarkers of Nutrition for Development (BOND)—Iron Review

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    This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health. The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation

    Expression in Escherichia coli of the Cellulomonas fimi Structural Gene for Endoglucanase B

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    Endoglucanase B (EB) of Cellulomonasfimi has an Mr of 110,000 when it is produced in Escherichia coli. The level of expression of the cenB gene (encoding EB) was significantly increased by replacing its normal transcriptional and translational regulatory signals with those of the E. coli lac operon. EB was purified to homogeneity from the periplasmic fraction of E. coli in one step by affinity chromatography on microcrystalline cellulose (Avicel). Alignment of the NH2-terminal amino acid sequence with the partial nucleotide sequence of a fragment of C. fimi DNA showed that EB is preceded by a putative signal polypeptide of 33 amino acids. The signal peptide functions and is processed correctly in E. coli, even when its first 15 amino acids are replaced by the first 7 amino acids of 0-galactosidase. The intact EB polypeptide is not required for enzymatic activity. Active polypeptides with Mrs of 95,000 and 82,000 also appear in E. coli, and a deletion mutant of cenB encodes an active polypeptide with an M, of 72,000

    Case-mix and the use of control charts in monitoring mortality rates after coronary artery bypass

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    BACKGROUND: There is debate about the role of crude mortality rates and case-mix adjusted mortality rates in monitoring the outcomes of treatment. In the context of quality improvement a key purpose of monitoring is to identify special cause variation as this type of variation should be investigated to identify possible causes. This paper investigates agreement between the identification of special cause variation in risk adjusted and observed hospital specific mortality rates after coronary artery bypass grafting in New York hospitals. METHODS: Coronary artery bypass grafting mortality rates between 1994 and 2003 were obtained from the New York State Department of Health's cardiovascular reports for 41 hospitals. Cross-sectional control charts of crude (observed) and risk adjusted mortality rates were produced for each year. Special cause variation was defined as a data point beyond the 99.9% probability limits: hospitals showing special cause variation were identified for each year. Longitudinal control charts of crude (observed) and risk adjusted mortality rates were produced for each hospital with data for all ten years (n = 27). Special cause variation was defined as a data point beyond 99.9% probability limits, two out of three consecutive data points beyond 95% probability limits (two standard deviations from the mean) or a run of five consecutive points on one side of the mean. Years showing special cause variation in mortality were identified for each hospital. Cohen's Kappa was calculated for agreement between special causes identified in crude and risk-adjusted control charts. RESULTS: In cross sectional analysis the Cohen's Kappa was 0.54 (95% confidence interval: 0.28 to 0.78), indicating moderate agreement between the crude and risk-adjusted control charts with sensitivity 0.4 (95% confidence interval 0.17–0.69) and specificity 0.98 (95% confidence interval: 0.95–0.99). In longitudinal analysis, the Cohen's Kappa was 0.61 (95% confidence interval: 0.39 to 0.83) indicating good agreement between the tests with sensitivity 0.63 (95% confidence interval: 0.39–0.82) and specificity 0.98 (95% confidence interval: 0.96 to 0.99). CONCLUSION: There is moderate-good agreement between signals of special cause variation between observed and risk-adjusted mortality. Analysis of observed hospital specific CABG mortality over time and with other hospitals appears to be useful in identifying special causes of variation. Case-mix adjustment may not be essential for longitudinal monitoring of outcomes using control charts

    Practical management of Chronic Myeloid Leukemia in Belgium

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    peer reviewedImatinib has drastically changed the outcome of patients with chronic myeloid leukemia (CML), with the majority of them showing a normal life span. Recently, the development of second and third generation tyrosine kinase inhibitors (TKIs) and the possibility of treatment discontinuation made the management of these patients more challenging. In this review, practical management guidelines of CML are presented, adapted to the Belgian situation in 2014. In first line chronic phase patients, imatinib, nilotinib and dasatinib can be prescribed. While second generation TKIs give faster and deeper responses, their impact on long-term survival remain to be determined. The choice of the TKI depends on CML risk score, priority for a deep response to allow a treatment-free remission protocol, age, presence of comorbid conditions, side effect profile, drug interactions, compliance concerns and price. Monitoring the response has to be made according the 2013 ELN criteria, and is based on the bone-marrow cytogenetic response during the first months and on the blood molecular response. Molecular follow-up is sufficient in patients with a complete cytogenetic response. For patients who fail frontline therapy, nilotinib, dasatinib, bosutinib and ponatinib are an option depending of the type of intolerance or resistance. T315I patients are only sensitive to ponatinib, which has to be carefully handled due to cardiovascular toxicity. Advanced phase diseases are more difficult to handle, with treatments including allogeneic stem cell transplantation, which is also an option for patients failing at least two TKIs. The possibility of treatment-free remission and pregnancy are also discussed
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