Alleviation of heavy metal stress in Spilanthes calva L. (antimalarial herb) by exogenous application of glutathione

To evaluate the role of exogenous application of a phytochelating agent glutathione in increasing resistance against different heavy metals stress, nodal explants excised from 28-day-old in vitro seedlings of Spilanthes calva L. were cultured on Murashige and Skoog’s medium supplemented with 10 μM benzyl adenine and five different concentrations (1, 5, 50, 100, or 200 mg/l) of four heavy metals: As₂O₃, CuSO₄, ZnSO₄, or Pb(NO₃)₂. Data were recorded for percent survival, shoot number, and shoot length after 28 d of heavy metal treatment. All four heavy metals severely inhibited growth and morphogenesis. Pb proved most inhibitory whereas Zn was least effective. Pb was further selected to study the reversal effect of glutathione on morphogenesis. The addition of different concentrations (1, 5, 10, or 25 mg/l) of glutathione to media containing the Pb resulted in a significant improvement in almost all growth parameters. Inclusion of glutathione at 10 mg/l was optimum for maximum reversal of the negative effects of heavy metals on morphogenesis.     

Comparative histochemical study of the enzyme changes in the ovary and uterus of mammals with special references to steroidogenesis.

A comparative study of the enzymes delta5-3beta-HSD, cytochrome oxidase and peroxidase has been made in the ovaries and uterus of mammals (mouse, guinea pig, cat and dog) during various reproductive phases. The granulosa cells of developing follicles, hypertrophied interstitial cells of thecal origin and the luteal cells show intense delta5-3beta-HSD and cytochrome oxidase activity. Peroxidases are found to be present in the corpus luteum and the epithelial cords of thecal origin. delta5-3beta-HSD and cytochrome oxidase activity is localized to the endometrium and myometrium of mature and pregnant uterus of mouse and guinea pig, while peroxidase is seen only in the decidua and endometrial glands of pregnant animals. The significance of these enzymes is discussed in relation to the cellular basis of luteinization and steroid hormone synthesis.     

Conjugated dienes in lipids of apolipoprotein B containing lipoproteins of normal and type 2 (non-insulin-dependent) diabetic patients.

Conjugated dienes present in the fatty acyl chains of cholesterol esters and triglycerides associated with plasma apolipoprotein B containing lipoproteins of normal and Type 2 (non-insulin-dependent) diabetic patients (n = 17) have been analysed using second derivative electronic absorption spectroscopy. Characteristic spectral patterns for both normal subjects and Type 2 diabetic patients were observed. Cis, trans and trans, trans conjugated dienes in cholesterol esters of lipoprotein B of Type 2 patients and normal subjects were found to be 41.74 +/- 0.51 mg/litre, 8.20 +/- 0.20 mg/litre (p less than 0.01) and 24.70 +/- 0.33 mg/litre, 9.22 +/- 0.06 mg/litre (p less than 0.01), respectively. Levels of these dienes in triglyceride fraction were 21.21 +/- 0.52 mg/litre, 7.72 +/- 0.02 mg/litre (p greater than 0.05) and 15.49 +/- 0.36 mg/litre, 7.91 +/- 0.11 mg/litre (p greater than 0.05), respectively.     

Purification and characterization of a wound-induced ω-hydroxyfatty acid:NADP oxidoreductase from potato tuber disks (Solanum tuberosum L.)

ω-Hydroxyfatty acid dehydrogenase (ω-hydroxyfatty acid:NADP oxidoreductase) catalyzes the reaction ω-hydroxyfatty acid + NADP ? ω-oxofatty acid + NADPH +H⁺. In wound-healing potato tuber disks, the ω-oxofatty acid generated by this enzyme is further oxidized to the corresponding dicarboxylic acid by a separate enzyme, ω-oxofatty acid dehydrogenase. ω-Hydroxy acid dehydrogenase, but not ω-oxo acid dehydrogenase, was found to be induced by wounding potato tubers. ω-Hydroxy acid dehydrogenase has been purified 600-fold to near homogeneity from wound-healing potato tuber disks by a combination of gel filtration, anion-exchange, and hydroxylapatite chromatography followed by NADP-Sepharose affinity chromatography, in about 1% yield. The molecular weight and Stokes radius of this enzyme as determined by gel exclusion chromatography are 60,000 and 31 Å, respectively. Sodium dodecyl sulfate-gel electrophoresis gave a molecular weight of 31,000, indicating that the deydrogenase is a dimer with subunits of similar molecular weight. The pH optima for the reaction in the forward and reverse directions are 9.5 and 8.5, respectively, and V in the forward and reverse directions are 140 and 3200 nmol/min/mg, respectively. Apparent K_m values for NADP, 16-hydroxyhexadecanoic acid, NADPH, and 16-oxohexadecanoic acid are 100, 20, 5, and 7 μm respectively. The equilibrium constant of the reaction at pH 9.5 and 30 °C is 1.4 × 10^?9m. The enzyme preparation did not show any stereospecificity for hydride transfer from NADPH to 16-oxohexadecanoic acid.     

Chemistry of the true cedars

Four species of Cedus, designated as “True Cedars”, are widely distributed over the Asian subcontinent and are well known for their wood and medicinal properties. Consequently they have been investigated extensively over the last three decades. A review of the chemical constituents in various parts of these species and the biological activities reported in these investigations is presented.     

Chloroquine delivery to erythrocytes inPlasmodium berghei-infected mice using antibody-bearing liposomes as drug vehicles

Suitability of anti-erythrocyte F_(ab’)2-bearing liposomes as vehicles for chloroquine in the treatment of chloroquine resistantPlasmodium berghei infections in mice has been examined. Free chloroquine or chloroquine encapsulated in antibody-free liposomes failed to show much effect on the resistant infections, but the same doses of this drug after being encapsulated in antibody-bearing liposomes exhibited a significant inhibitory effect on this infection. These results indicate that chloroquine delivery in antibody targeted liposomes may help in the successful treatment of the chloroquine resistant malarial infections. CDRI Communication No. 4705.     

Late quaternary sediments,minerals, and inferred geochemical history of Didwana Lake,Thar Desert,India

Variations in clastic sediment texture, mineralogy of both evaporites formed at the surface and precipitates formed below the lake floor, and the relative chemical activities of the major dissolved components of the chemical precipitates, have allowed reconstruction of the history of salinity and water-level changes in Didwana Lake, Thar Desert, India. Hypersaline conditions prevailed at about the Last Glacial Maximum, with little evidence of clastic sediments entering the lake. Between ca. 13,000 and 6000 B.P. the lake level fluctuated widely, the lake alternately hypersaline and fresh, and clastic sediments were delivered to the lake at a low rate. Deep-water conditions occurred ca. 6000 B.P. and clastic influx increased abruptly. The water level dropped towards 4000 B.P. when the lake dried briefly. Since 4000 B.P. the lake has been ephemeral with a lowered rate of sedimentation and mildly saline conditions rather like those of today. This sequence of changes documented in the lake parallels changes in vegetation recorded in published pollen diagrams from both the Thar and the Arabian Sea. Correlation of the various lines of evidence suggests that the climate of the Last Glacial Maximum at Didwana was dry and windy with a weak monsson circulation. The monsson was re-established between ca. 13,000 and a little before 6000 B.P., and, when winter rainfall increased ca. 6000 B.P., the lake filled to its maximum depth.