Schistosomiasis in Cameroon: an assessment of community knowledge pattern.

OBJECTIVE: Schistosomiasis is one of the most widespread of all human parasitic diseases and is a serious health problem in Cameroon despite tremendous efforts by health authorities. The purpose of this study was to determine community knowledge of the infection in order to evaluate control programmes put in place. METHODS: A random sampling method was used to administer questionnaires to 3200 individuals in 80 communities throughout the ten regions of the country. RESULTS: Globally the percentage of persons with good knowledge of schistosomiasis was low (28.8%). Of the 2586 who responded 1311 (50.7%) were females and 1275 (49.3%) were males. There was a statistically significant difference in the community knowledge pattern by gender (chi2 = 157.28, P < 0.05), and persons with good knowledge were more frequent among males than females (61.8% vs. 38.2% P < 0.05). The percentage of people who had good knowledge about the disease was highest in the Far North region (35.4), followed by the North (33.8) and the Southwest (31.1) regions. There was a statistically significant difference in community knowledge pattern of Schistosomiasis by region and gender (chi2 = 1265.648 P < 0.001). Also, there was a statistically significant difference in community knowledge pattern of by setting (chi2 = 38.538 P = 0.001) and the percentage of people who had a good knowledge of the disease was higher in rural areas than in urban areas (72.5% vs. 3.1% P < 0.05). CONCLUSION: was a low community knowledge pattern of schistosomiasis, mostly among the female population and among people living in urban areas. We advocated that health education should be adopted as one of the control strategies by the

Molecular and biochemical approaches in the identification of heterozygotes for homocystinuria.

We compared biochemical and molecular methods for the identification of heterozygous carriers of mutations in the cystathionine beta-synthase (CBS) gene. Eleven relatives of seven unrelated patients with homocystinuria due to homozygous CBS deficiency and controls were studied with respect to total homocysteine concentrations before and after methionine loading. In addition, we determined CBS activity in cultured skin fibroblasts and tested for the presence of five known mutations by a PCR-based method in these seven patients, their relatives and controls. The results demonstrate that measurement of homocysteine after methionine loading and assay of CBS enzyme activity in cultured fibroblasts identify most but not all heterozygotes. There was significant correlation between homocysteine concentrations and CBS activities only after methionine loading (r = 0.12, 0.48, 0.48 and 0.50 at 0, 4, 6 and 8 h, respectively). Among the homozygous patients, molecular approaches identified five T833C and two G919A mutations out of 14 independent alleles, confirming the studies of others that these represent the two most prevalent mutations. In addition, we found that three of six heterozygotes with the T833 C allele had post-methionine loading homocysteine levels which overlapped with controls and of the other three, one (as well as an obligate heterozygote who did not carry any of the five mutant alleles tested) had CBS activity comparable to that of controls. These findings demonstrate that genotyping is useful as an adjunctive method for the diagnosis of the heterozygous carrier state of CBS deficiency.

Fluorescence probes in biochemistry: an examination of the non-fluorescent behavior of dansylamide by photoacoustic calorimetry.

Photoacoustic calorimetry is shown to be a simple, precise, and accurate method for the quantification of the photophysics of a fluorescence probe, e.g., dansylamide, in a variety of solvents. This technique, which is described in detail, provides a direct measurement of the energy that is released nonradiatively following photostimulation, and can therefore be used to indirectly determine the amount of energy released via luminescent pathways. Photoacoustic calorimetry combined with established absorption and fluorescence methodologies provides a complete arsenal for characterizing the photophysical properties of many systems. Comparison of the photoacoustic signal for dansylamide versus standard compounds (ferrocene, tetraphenylethylene, 8-anilinonaphthalene-1-sulfonate, and/or 5,5'-dithiobis(2-nitrobenzoic acid) in 12 different solvents gave fh values (fraction of each absorbed 337.1-nm photon returned as heat) from a low of 0.530 in 1,4-dioxane to a high of 0.973 in water. The trend noted with solvent polarity is different and more revealing than that determined by the more classical approach of examining either the wavelength of the emission maximum or the fluorescence quantum yield.