Amylase induction during seed germination in isoproturon susceptible and resistant biotypes of Phalaris minor Retz.

Isoproturon resistant biotype of P. minor germinates early, shows higher germination percentage and faster rate of growth as compared to the susceptible biotype. Higher amylase activity is observed in the initial hours of imbibition in the resistant biotype. In the susceptible biotype it is activated at a much later stage.

Glibenclamide vs gliclazide in reducing oxidative stress in patients of noninsulin dependent diabetes mellitus--a double blind randomized study.

OBJECTIVE: Parameters of oxidative stress were quantitated in 50 patients with type 2 diabetes mellitus in uncontrolled state and after control using oral glibenclamide or gliclazide. The estimates were further compared between the two groups irrespective of drug used to evaluate the difference, if any. METHODS: The study was a double blind, uncontrolled, noncrossover and randomized trial. Fifty patients of uncontrolled type 2 diabetes were divided in to two groups. Group I (25 patients) received capsule A (glibenclamide) while Group II (25 patients) received capsule B (gliclazide). The parameters studied were Superoxide dismutase (SOD), malonyl-dialdehyde (MDA) and reduced glutathione (GSH). They were done at (a) uncontrolled stage (FBS--165 +/- 16.7 mg/dl, PP--240 +/- 30.1 mg/dl and HbA1--10.5 +/- 0.9% in group I and FBS--150 +/- 15.8 mg/dl, PP--246 +/- 29.1 mg/dl HbA1 10.6 +/- 0.8% in group II) and during controlled stage at 12 weeks (FBS--120 +/- 18.5 mg/dl, PP--180 +/- 19.1 mg/dl and HbA1--8.4 +/- 0.29% in group I and FBS--118 +/- 17.6 mg/dl, PP--176 +/- 20.1 mg/dl and HbA1--8.5 +/- 0.39% in group II patients). RESULTS: The significantly raised levels of MDA and SOD, and decreased levels of reduced glutathione (GSH) during uncontrolled stage of diabetes indicated free radical stress induced lipid peroxidation. The significant fall of MDA and SOD and increased levels of GSH in blood in both groups after control revealed beneficial effects of glycemic control on oxidative stress. The levels were not normalized and stayed higher than those in controls. On intergroup comparison; the control of diabetes with gliclazide (group II) showed improvement in oxidative stress (MDA, GSH) better (p < 0.001) than glibenclamide (group I). CONCLUSION: Oxidative stress in uncontrolled diabetes is decreased with glycemic control. The control of diabetes with gliclazide reduced oxidative stress more than glibenclamide, indicating higher antioxidant properties of gliclazide. Normalization of oxidative stress was not achieved. Further studies are required to see long-term effect of drug therapy in combating oxidative stress after achieving acceptable control of diabetes.

Identification and characterization of receptor for dengue virus-induced macrophage cytotoxin.

The present study was undertaken to identify the receptor for dengue virus type 2 (DV) induced macrophage cytotoxin (CF2) on mouse peritoneal macrophages (MPhi). The binding of 125I-labelled CF2 to MPhi was saturable (15 nM), reversible, temperature, pH- and time-dependent. The saturation concentration was similar to that causing cell death. Scatchard analysis showed the presence of intermediate type of affinity receptor and the number of receptor sites was 1.1 x 10(6) per cell with dissociation constant of 14.28 nM.

Role of calcium in induction of dengue virus-specific helper T cells.

Dengue type 2 virus (DV) induces the generation of T helper cells (TH) in the mouse spleen. These TH on adoptive transfer to DV primed syngeneic mice enhance the clonal expansion of antigen-specific antibody plaque forming cells. The present study was undertaken to investigate the role of M phi and Ca2+ in the induction of DV-specific TH. The results show that M phi are obligatory for the induction of DV-specific TH. It was observed that DV antigen stimulate the influx of calcium ion (Ca2+) into T cells as shown by radiolabelled (45Ca) and the influx of Ca2+ increases with time of incubation, reaching a maximum level after 1 hr of incubation. The proliferation of T cells was found to be dependent on presence of Ca2+ as it was inhibited by Ca channel blocking drugs and in the absence of Ca in the medium. Thus showing that Ca2+ plays an important role in the induction of DV-specific TH cells.

Flow cytometric analysis of T4:T8 splenic cell during dengue virus infection of mice.

The present study was undertaken to investigate the effect of dengue type 2 virus (DV) and DV-induced cytokines (CF and CF2) on T lymphocyte subpopulations of spleen by flow cytometry. Following DV-ic inoculation in mice the percent number of CD4+ and CD8+ lymphocytes in the spleen was reduced, the peak reduction in both was observed on the 6th day post-inoculation (p.i.). Intravenous inoculation of CF or CF2 in mice also decreased the percent number of CD4+ as well as CD8+ T lymphocytes subpopulation in the spleen, the maximum reduction being observed at 1 and 2 hr, respectively. The reduction in T lymphocyte subpopulation by CF and CF2 was found to be dose dependent. Thus, the alterations of T lymphocyte subpopulations during DV infection are mediated via cytokines.