Epidemiological survey of rhinosporidiosis in Kanyakumari district of Tamil Nadu

One hundred and twelve nasal polyps received along with full history from three different hospitals of Kanyakumari district of Tamil Nadu during the period 1983–1987 were found positive for rhinosporidiosis on histopathological examination. Among the four taluks (countries) the majority of the cases (41.1 per cent) came from Agastheeswaram, followed by Kalkulam (28.6 per cent), Thovalai (17.0 per cent) and Vilavancode (13.3 per cent). The 11–20 years age group found to be highly susceptible (60 per cent). There was no sex prepondence in contracting the disease as the cases were evenly distributed between both sexes. These findings exhibited the endemic nature of the disease in Kanyakumari district.Unreported cases to an extent of 9 to 40 per cent were encountered during the ENT disease diagnostic camps conducted in nine high incidence villages. Further 8 more cases were detected in addition to cases attended in the hospitals and ENT camps when a complete enumeration of cases was undertaken in Pallam village. Thus the actual number of cases found in the district need a stratified random sampling.     

Characterization of chemically treated bacterial (Acetobacter xylinum) biopolymer: some thermo-mechanical properties

Bacterial cellulose prepared from pellicles of Acetobacter xylinum (Gluconacetobacter xylinus) is a unique biopolymer in terms of its molecular structure, mechanical strength and chemical stability. The biochemical analysis revealed that various alkali treatment methods were effective in removing proteins and nucleic acids from native membrane resulting in pure cellulose membrane. The effect of various treatment regimens on thermo-mechanical properties of the material was investigated. The cellulose in the form of purified cellulose membranes was characterized by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The glass transition temperature (T(g)) of the native cellulose (untreated, compressed and dried pellicle) was found to be 13.94 degrees C, in contrast, the chemically treated cellulose membranes has higher T(g) values, ranging from 41.41 degrees C to 48.82 degrees C. Investigations on isothermal crystallization were carried out to study the bulk crystallization kinetics. Thermal decomposition pattern of the native as well as alkali treated cellulose was determined by obtaining thermo-gravimetric curves. At higher temperatures (>300 degrees C), the biopolymer was found to degrade. Nevertheless, the alkaline treated cellulose membrane was more stable (between 343.27 degrees C and 370.05 degrees C) in comparison to the native cellulose (298.07 degrees C). Further, the percentage weight loss in case of native cellulose was found to be 26.57%, in comparison to 6.45% for the treated material, at 300 degrees C. The DMTA revealed complex dynamic modulus of the material, at different temperatures and fixed shear stress, applied at a frequency of 5 Hz. The study delineated the effect of alkali treatment regimens, on the thermo-mechanical properties of bacterial cellulose for its application over a wide range of temperatures.