A controlled, parallel, cluster-randomized trial of community-wide screening and treatment of asymptomatic carriers of Plasmodium falciparum in Burkina Faso

Background

In malaria-endemic countries, large proportions of infected individuals are asymptomatic, constituting a reservoir of parasites for infection of newly hatched mosquitoes. This study evaluated the impact of screening and treatment of asymptomatic carriers of Plasmodium falciparum.

Methods

Eighteen villages were randomized (1:1) to study arms and inhabitants participated in four community screening campaigns: three before the rainy season ~1 month apart, and the fourth after the rains at ~12 months. On day 1 of campaigns 1–3, asymptomatic carriers in the intervention arm were identified by rapid diagnostic test and treated with artemether-lumefantrine. Outcomes were symptomatic malaria with parasite density >5,000/μL per person-year in children < 5 years and change in haemoglobin between days 1 and 28 of campaign 1.

Results

At 12 months, the number of symptomatic malaria episodes with a parasite density >5,000/μL per person-year in children < 5 years was not significantly different between arms (1.69 vs 1.60, p = 0.3482). Mean haemoglobin change in asymptomatic carriers during campaign 1 was greater in the intervention vs control arm (+0.53 g/dL vs -0.21 g/dL, p < 0.0001). ANCOVA demonstrated that mean asymptomatic carriage at the cluster level was lower in the intervention vs control arm at day 1 of campaigns 2 (5.0% vs 34.9%, p < 0.0001) and 3 (3.5% vs 31.5%, p < 0.0001), but showed only a small difference at day 1 of campaign 4 (34.6% vs 37.6%, p = 0.2982). Mean gametocyte carriage was lower in the intervention vs control arm at day 1 of campaigns 2 and 3 (0.7% vs 5.4%, p < 0.0001; 0.5% vs 5.8%, p < 0.0001), but was similar at day 1 of campaign 4 (4.9% vs 5.1%, p = 0.7208).

Conclusions

Systematic screening and treatment of asymptomatic carriers at the community level did not reduce clinical malaria incidence in the subsequent transmission season, indicating greater levels of parasite clearance are required to achieve a sustained impact in this setting.

Prediction of pre-eclampsia: comparative analysis of two screening tests

Pre-eclampsia is a major cause of maternal and perinatal morbidity and mortality. Unfortunately, in spite of extensive research worldwide, still we lack an effective screening test for pre-eclampsia. The aim of the current study is to assess the importance of micro-albuminuria and uterine artery Doppler resistance index as a screening test for pre-eclampsia during antenatal period. The study is a prospective audit. The study population consisted of 160 antenatal mothers attending the outpatient department. Test for micro-albuminuria was done at 14 weeks, 18 weeks, 28 weeks and 34 weeks of gestation. Uterine artery Doppler resistance index (0.58 taken as cut-off) was recorded at 18 weeks of gestation. The subjects were followed up till delivery for development of pre-eclampsia. Sensitivity, specificity, positive and negative predictive value (along with confidence interval and diagnostic odd's ratio) of the tests were calculated. Sensitivity, specificity, positive and negative predictive value of micro-albuminuria was recorded as 66.67%, 93.24%, 44.44% and 97.18% respectively. Those of uterine artery Doppler resistance index were 33.33%, 95.96%, 40% and 94.67% respectively. Diagnostic odd's ratio of micro-albuminuria and uterine artery Doppler resistance index were 27.600 and 11.833 respectively. Confidence interval and diagnostic odd's ratios show that uterine artery Doppler study is a better screening test amongst the two. Both the tests being non-invasive in nature and having high specificity and high negative predictive value can be utilised in community-based antenatal care for identifying women who need intensive vigilance.

New insights into the chemistry of fac-[Ru(CO)₃]²⁺ fragments in biologically relevant conditions: the CO releasing activity of [Ru(CO)₃Cl₂(1,3-thiazole)], and the X-ray crystal structure of its adduct with lysozyme

Complexes of the general formula fac-[Ru(CO)(3)L(3)](2+), namely CORM-2 and CORM-3, have been successfully used as experimental CO releasing molecules (CO-RMs) but their mechanism of action and delivery of CO remain unclear. The well characterized complex [Ru(CO)(3)Cl(2)(1,3-thiazole)] (1) is now studied as a potential model CO-RM of the same family of complexes using LC-MS, FTIR, and UV-vis spectroscopy, together with X-ray crystallography. The chemistry of [Ru(CO)(3)Cl(2)(1,3-thiazole)] is very similar to that of CORM-3: it only releases residual amounts of CO to the headspace of a solution in PBS7.4 and produces marginal increase of COHb after long incubation in whole blood. 1 also reacts with lysozyme to form Ru adducts. The crystallographic model of the lysozyme-Ru adducts shows only mono-carbonyl Ru species. [Ru(H(2)O)(4)(CO)] is found covalently bound to a histidine (His15) and to two aspartates (Asp18 and Asp119) at the protein surface. The CO release silence of both 1 and CORM-3 and their rapid formation of protein-Ru(CO)(x)(H(2)O)(y) (x=1,2) adducts, support our hypothesis that fac-[Ru(CO)(3)L(3)] CO-RMs deliver CO in vivo through the decay of their adducts with plasma proteins.

Arsenic(III) sorption on nanostructured cerium incorporated manganese oxide (NCMO): a physical insight into the mechanistic pathway

Arsenic(III) sorption was investigated with nanostructured cerium incorporated manganese oxide (NCMO). The pH between 6.0 and 8.0 was optimized for the arsenic(III) sorption. Kinetics and equilibrium data (pH=7.0±0.2, T=303±1.6 K, and I=0.01 M) of arsenic(III) sorption by NCMO described, respectively, the pseudo-second order and the Freundlich isotherm equations well. The sorption process was somewhat complicated in nature and divided into two different segments, initially very fast sorption followed by slow intraparticle diffusion process. Sorption reaction of arsenic(III) on NCMO was endothermic (ΔH°=+13.46 kJ mol(-1)) and spontaneous (ΔG°=-24.75 to -30.15 kJ mol(-1) at T=283-323 K), which took place with increasing entropy (ΔS°=+0.14 kJ mol(-1)K(-1)) at solid-liquid interface. Energy of arsenic(III) sorption estimated by analyzing the equilibrium data using the D-R isotherm model was 15.4 kJ mol(-1), indicating the ion-exchange type mechanism. Raman, FT-IR, pH effect, desorption, etc. studies indicated that arsenic(III) was oxidized to arsenic(V) during the sorption process.

Imatinib mesylate therapy in patients of chronic myeloid leukemia with Philadelphia chromosome positive: an experience from eastern India

Imatinib inhibits constitutively active BCR-ABL tyrosine kinase of chronic myeloid leukemia (CML). In a long term study it was found superior to interferon alfa plus cytarabine for newly diagnosed CML in the chronic phase. However, till date there is no major study to evaluate eastern Indian CML patients treated with imatinib mesylate. The aim of our study was to see the efficacy, tolerability, toxicity and safety of imatinib in eastern Indian subset of CML population. The present study enrolled 831 patients with CML out of which 197 were excluded due to various reasons of noncompliance, death and not being fit to receive the drug. The rest, 634 (76% of total enrolled) were selected for the evaluation. In the beginning of the study, 603 patients were in chronic phase, 27 in accelerated phase and 4 patients in blast crisis phase. Among 634 patients, 280 patients (44%) received previously either interferon alpha or hydroxyurea and other 354 patients (56%) were previously untreated. Complete hematological remission and major cytogenetic response were 91 and 67%, respectively after 1 year of treatment. Complete molecular remission was 35% after 1 year of treatment. Sixty-four patients (10.1%) were resistant to imatinib mesylate in 5 years. The disease free and overall survival at 60 months were 72.2 and 76.1% respectively. After 60 months of follow up, continuous treatment of chronic phase CML with imatinib as initial therapy was found to be safe and able to induce durable responses in a high proportion of patients.