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Background Expert opinion derived disability weights are widely employed for estimating the global burden of diseases and injuries. For chronic diseases such as soil transmitted helminthiasis and schistosomiasis it has been suggested that a patient based quality of life (QoL) approach should be considered for a more accurate appraisal of disability weights. Methods and Results We carried out a cross sectional survey and assessed the prevalence and intensity of soil transmitted helminth infections as well as self rated QoL indicators among 252 students attending grades 5 8 in two schools (Bulangshan and Pu'er) in Yunnan province People's Republic of China. Each student provided a single stool sample which was subjected to duplicate Kato Katz thick smear readings and a single FLOTAC examination for parasitological diagnosis. Prevalence rates for hookworm Trichuris trichiura and Ascaris lumbricoides were high in Bulangshan (75.9 70.0 and 68.2) while the respective prevalence rates in Pu'er were 66.9 56.5 and 9.2. Students were interviewed with two standardised questionnaires the EuroQoL 5 Dimensions (EQ 5D) and ShortForm 12 (SF 12) Health Survey. Impairment in any of the five dimensions of the EQ 5D was reported by 87 of the students. However no clear differences could be observed between individuals with and those without helminth infections and there were discrepancies between the two schools. A multivariate logistic regression model revealed no differences between students with varying infection status in the domains of the SF 12 (odds ratio close to 1.0). Somewhat more pronounced yet not statistically significant differences were observed when end of school term marks were compared with students' helminth infection status: infected individuals had lower marks in Chinese English and mathematics but not in sports compared to their helminth free counterparts. Conclusions Our results point to unresolved issues and challenges regarding the cultural appropriateness of the widely used standard QoL questionnaires. Hence new research is needed to further develop these instruments and to validate them in connection with chronic parasitic diseases.

The purification, cloning, and complete cDNA-derived sequence of a 17-kDa protein of Dictyostelium discoideum are described. This protein binds to F-actin in a pH-dependent and saturable manner. It induces actin polymerization in the absence of Mg2+ or K+, and is enriched in the submembranous region of the amoeboid cells as indicated by immunofluorescence labeling of cryosections. The mRNA as well as the protein are present throughout growth and all stages of development. The protein is detected in both soluble and particulate fractions of the cells. From a plasma membrane-enriched fraction, minor amounts of the protein are stepwise solubilized with 1.5 M KCl, 0.1 M NaOH, and Triton X-100, but most of the protein is only solubilized with 1% sodium dodecyl sulfate. As judged by the apparent molecular mass in sodium dodecyl sulfate-polyacrylamide gels, immunological cross-reactivity, and two-dimensional electrophoresis, the 17-kDa proteins from the soluble and particulate fraction resemble each other. The cDNA sequence does not reveal any signal peptide, trans-membrane region, or N-glycosylation site. Southern blots hybridized with a cDNA probe that spans the entire coding region show that the 17-kDa protein is encoded by a single gene. The most characteristic feature of the protein is its high content of 31 histidine residues out of 118 amino acids. We designate this protein as hisactophilin and suggest that this histidine-rich protein responds in its actin-binding activity to changes in cellular pH upon chemotactic signal reception.