Structural and functional characterization of an iron-sulfur cluster assembly scaffold protein-SufA from Plasmodium vivax.

Iron-sulfur (Fe-S) clusters are utilized as prosthetic groups in all living organisms for diverse range of cellular processes including electron transport in respiration and photosynthesis, sensing of ambient conditions, regulation of gene expression and catalysis. In Plasmodium, two Fe-S cluster biogenesis pathways are reported, of which the Suf pathway in the apicoplast has been shown essential for the erythrocytic stages of the parasite. While the initial components of this pathway detailing the sulfur mobilization have been elucidated, the components required for the assembly and transfer of Fe-S clusters are not reported from the parasite. In Escherichia coli, SufB acts as a scaffold protein and SufA traffics the assembled Fe-S cluster from SufB to target apo-proteins. However, in Plasmodium, the homologs of these proteins are yet to be characterized for their function. Here, we report a putative SufA protein from Plasmodium vivax with signature motifs of A-type scaffold proteins, which is evolutionarily conserved. The presence of the [Fe4S4](3+) cluster under reduced conditions was confirmed by UV-visible and EPR spectroscopy and the interaction of these clusters with the conserved cysteine residues of chains A and B of PvSufA, validates its existence as a dimer, similar to that in E. coli. The H-bond interactions at the PvSufA-SufB interface demonstrate SufA as a scaffold protein in conjunction with SufB for the pre-assembly of Fe-S clusters and their transfer to the target proteins. Co-localization of the protein to the apicoplast further provides an experimental evidence of a functional scaffold protein SufA for the biogenesis of Fe-S clusters in apicoplast of Plasmodium.

Comparative evaluation of microscopy, OptiMAL(®) and 18S rRNA gene based multiplex PCR for detection of Plasmodium falciparum & Plasmodium vivax from field isolates of Bikaner, India.

OBJECTIVE: To evaluate microscopy, OptiMAL(®) and multiplex PCR for the identification of Plasmodium falciparumm (P. falciparum) and Plasmodium vivax (P. vivax) from the field isolates of Bikaner, Rajasthan (Northwest India). METHODS: In this study, a multiplex PCR (P. falciparum and P. vivax) was further developed with the incorporation of Plasmodium malariae (P. malariae) specific primer and also a positive control. The performance of microscopy, plasmodium lactate dehydrogenase (pLDH) based malaria rapid diagnostic test OptiMAL(®) and 18S rRNA gene based multiplex PCR for the diagnosis of P. falciparum and P. vivax was compared. RESULTS: The three species multiplex PCR (P. falciparum, P. vivax and P. malariae) with an inbuilt positive control was developed and evaluated. In comparison with multiplex PCR, which showed the sensitivity and specificity of 99.36% (95%CI, 98.11%-100.00%) and 100.00% (95%CI, 100.00%-100.00%), the sensitivity and specificity of microscopy was 90.44% (95%CI, 88.84%-95.04%) and 99.22% (95%CI, 97.71%-100.00%), and OptiMAL(®) was 93.58% (95%CI, 89.75%-97.42%) and 97.69% (95%CI, 95.10%-100.00%). The efficiencies were 99.65%, 95.10% and 95.45% for multiplex PCR, microscopy and OptiMAL(®), respectively. CONCLUSIONS: Our results raise concerns over the overall sensitivities of microscopy and OptiMAL(®), when compared to the multiplex PCR and thus stress the need for new molecular interventions in the accurate detection of the malarial parasites. This further highlights the fact that further developments are needed to improve the performance of rapid diagnostic tests at field level.

Evaluation of the quality and contents of diabetes mellitus patient education on Internet.

Patient education is widely regarded as an essential component of chronic disease care and effective health promotion. Internet is extremely useful medium in this respect. Web-based information is seldom the subject of systematic investigation for its accuracy and appropriateness for patients. Objective of this study was to evaluate of web-based diabetes patient education material for well-accepted evaluation criteria and core education concepts. Out of 214 web-sites retrieved from meta search engine, 53 sites themselves provide patient information and so considered for evaluation. Data obtained was analyzed by cluster analysis and classified into four categories with respect to quality. Considerable variability in quality of diabetes patient education web-sites was found with respect to core educational concepts and HSWG criteria. Inclusion of evidence-based medicine concepts, role of family support, enhancement in customized content and easier feedback mechanism in the web-sites can be a significant development in the direction of patient-centered diabetes care.

Maternal knowledge and perceptions aboutthe routine immunization programme--a study in a semiurban area in Rajasthan.

A cross sectional study on immunization coverage in the town of Pilani was conducted and a total of 166 mothers were interviewed using a pre-tested interview schedule/questionnaire on Knowledge, Attitudes, Perceptions and Expectations (KAPE). The results showed that among the 12-24 month old children 50% fully, 31.3% partially and 18.7% not at all immunized. High levels of initial vaccination rates and low levels of OPV3/DPT3 (62.7%) and measles (51.8%) vaccines indicate that completing vaccination schedule needs attention. Almost all the children in the study, 165 out of 166 received two doses of polio vaccine from the Pulse Polio Immunization programme. Majority of the mothers expressed favourable attitudes and satisfaction regarding the programme. Though many were aware of the importance of vaccination in general, specific information about importance of completing the schedule and knowledge about vaccine preventable diseases other than poliomyelities was very limited. Obstacles, misconceptions/beliefs among the mothers of partially immunized children and lack of information among not at all immunized group were the main reasons of non-immunization. The implications of the study are: to enhance the maternal knowledge about the vaccine preventable diseases and importance of completing the immunization schedule through interpersonal mode and to overcome obstacles to immunization such as accessibility and lack of family support.