Chitosan polymer used as carrier in various pharmaceutical formulations: Brief review.

Chitosan (CS) is a naturally occurring polymer which finds a wide array of pharmaceutical applications due to its low production costs, biodegradability, biocompatibility, nontoxic nature and mucoadhesion. It has been used in the blueprint of many different types of drug carriers; for various administration rules such as oral, buccal, nasal, transdermal, parenteral, vaginal, cervical, intrauterine and rectal. CS microspheres can be prepared by chemical denaturation process, solvent evaporation method and complex coacervation methods.

Age related changes in Fas (CD95) and Fas ligand gene expression and cytokine profiles in healthy Indians.

Ageing in human and animal models show changes in many aspects of protective immunity, particularly lymphopoenia and progressive decline in immune functions leading to increased frequency of infection and neoplasia. However, the exact mechanism of these defects is still unclear. In this study, elderly subjects showed a decline in CD3+ and CD4+ T-cell subsets as well as serum IL-2 levels. Serum IL-6 was significantly raised while expression of its signaling receptor gp130 was significantly impaired in elderly as compared to the younger ones. Additionally, all the elderly individuals showed constitutive expression of Fas and FasL mRNA; however, none of the younger individuals expressed mRNA transcripts constitutively although induced expression was seen in both the groups. Similarly, frequency of Fas and FasL expressing CD4+ and CD8+ T-cell subsets were significantly (p < 0.001) higher in elderly subjects as compared to the younger ones. Elderly individuals also showed a significantly (p < 0.001) higher frequency of activation induced cell death (AICD). Since interaction of Fas with its cognate ligand (FasL) activates death inducing caspases leading to apoptosis, and gp130 induces anti-apoptotic signal through STAT-3 pathway, these results suggest that the decline in protective immune functions in aged individuals may be related to Fas and FasL mediated apoptosis of peripheral T-cell subsets.

Cross-resistance to Bacillus sphaericus strains in Culex quinquefasciatus resistant to B. sphaericus 1593M.

Bacillus sphaericus 1593M resistant larvae of Culex quinquefasciatus were reared in the laboratory since 1995. Resistance in the larvae was monitored by subjecting selection pressure using B. sphaericus 1593M at every generation. Bioassays were conducted with different strains of B. sphaericus (Bs 2297, Bs 2362 and Bs IAB 59) and confirmed cross-resistance in the present study. The level ranged between 27.3 to 18.2 fold in comparison with susceptible larvae. But Bacillus thuringiensis var israelensis strains (Bti PG14 and Bti 426) did not show any cross-resistance in the larvae and it emphasized a need to study the mode of action of B. sphaericus toxin that induces cross-resistance in the larval strain.

Space-spraying with malathion as a supplementary measure for operational malaria control.

Entomological studies showed that due to outdoor resting by the vector Anopheles culicifacies as well as poor spray coverage, indoor residual spraying with malathion was ineffective in malarious villages of the Thenpennai riverine tract in Tamil Nadu. Over a 4 yr period during which residual spraying was supplemented with ground applications of malathion space spraying, the slide positivity among patients with fever fell from 21.04 to 1.1 per cent. In mass blood surveys 0.7 per cent persons surveyed at the beginning of the study were positive for the malarial parasite, but no positives were detected in the last survey, in 1984. There was a rising trend in malaria incidence in riverine villages outside the programme.