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Biomedical subjects

P Vijayakumar

Publications and source records attributed to P Vijayakumar.

6 recordsLinked to original sources

Perinatal immunomodulation.

The fetus and the neonate are particularly vulnerable to injury caused directly by immunologic mechanisms or inflicted by infectious agents that take advantage of their relatively immature and inexperienced immune system. With increasing survival of high-risk neonates in the surfactant era, prevention/treatment of sepsis and chronic lung disease (CLD) has emerged as an area of priority in neonatal research. Considering the role of inflammatory mediators in the pathogenesis of sepsis and CLD, the clinical application of immunomodulator therapy to neonatology is perhaps more important at present than ever. Advances in molecular biology and immunology have led to development of newer immune modulator therapies that are directed towards specific cells or cytokines rather than resulting in a general suppression of the immune response. Failure of promising, newer immunomodulator therapies in sepsis trials in adults has, however, clearly documented the difficulties in diagnosing/correcting the imbalance between pro- and anti-inflammatory responses. As in the case of sepsis, development of a single magic bullet for prevention/management of a multi-factorial illness like CLD may be difficult, as prevention of prematurity - the single most important high-risk factor for CLD - is an unachievable goal at present. As new frontiers are being explored, older, well-established therapies like antenatal anti-D immunoglobulin prophylaxis continue to emphasize the tremendous potential of immunomodulator therapy in neonatology/perinatology. The current immunomodulators/immunotherapeutic agents with established/potential clinical applications in the perinatal period are reviewed.

Adjuvants, Immunologic↗

alpha,alpha-Trehalase of Trichoderma reesei.

A simple adsorption and elution of the trehalase of Trichoderma reesei on bentonite increased the specific activity 70-80 times, with a recovery of 90%. This alpha,alpha-trehalase has an optimum pH of 4.4, a pl of 5.7, a Km of 3.1 X 10(-3) M, and a specific activity of 50 mumol/mg. min-1.

Adsorption↗

beta-Glucosidase: microbial production and effect on enzymatic hydrolysis of cellulose.

The enzymatic conversion of cellulose is catalyzed by a multiple enzyme system. The Trichoderma enzyme system has been studied extensively and has insufficient beta-glucosidase (EC 3.2.1.21) activity for the practical saccharification of celluose. The black aspergilli (A. niger and A. phoenicis) were superior producers of beta-glucosidase and a method for production of this enzyme in liquid culture is presented. When Trichoderma cellulase preparations are supplemented with beta-glucosidase from Aspergillus during practical saccharifications, glucose is the predominant product and the rate of saccharification is significantly increased. The stimulatory effect of beta-glucosidase appears to be due to the removal of inhibitory levels of cellobiose.

Aspergillus↗