NISCAIR Online Periodicals Repository Collection: IJEB Vol.50(08) [August 2012]

Increase in voltage gated potassium currents of human lymphocytes on culture

Title: Increase in voltage gated potassium currents of human lymphocytes on culture

Authors: Snekalatha, S; Kanthakumar, Praghalathan

Abstract: Voltage gated potassium channels present in T lymphocytes play an important role during lymphocyte activation. Though an increase in potassium currents has been reported in activated lymphocytes, changes in potassium currents in culture without activation by antigen or mitogen has not been reported. The peak potassium current densities on day 1 and day 5 of culture have been compared in this study. Peripheral blood mononuclear cells (PBMCs) were separated by density gradient centrifugation. Lymphocytes were separated from PBMCs by negative selection using anti-CD14 coated magnetic beads and cultured under appropriate conditions without antigenic or mitogenic stimulation. Lymphocytes were patched on day 1 or day 5 of culture. Voltage gated potassium currents were recorded by whole cell patch clamp technique using a depolarizing protocol. The mean of peak current densities recorded at +60 mV on day 1 of culture was 228.12± 89.39 pA/pF (n=7) and on day 5 of culture was 468.96 ± 192.07 pA/pF (n=7). The difference between the current densities on day 1 and day 5 was found to be significant. Change in electrophysiological characteristics can lead to functional changes in the lymphocytes and this should be considered when culturing lymphocytes in vitro for research and clinical use.

Page(s): 587-590

Influence of genetic relatedness and shoal size on shoaling preferences in juvenile Puntius sarana subnasutus (Hamilton Valenciennes)

Title: Influence of genetic relatedness and shoal size on shoaling preferences in juvenile Puntius sarana subnasutus (Hamilton Valenciennes)

Authors: Alex, N Jilna; Thomas, K John

Abstract: When presented with stimulus shoals of siblings and conspecifics in equal number, P. sarana subnasutus were able to discriminate their siblings and preferred to associate with them. Given a choice between large shoal and a small shoal consisting of siblings, the juvenile fish preferred to associate with larger stimulus group to the smaller one. However, juveniles traded off their preference for sibling shoal with large non-sibling conspecific stimulus group, regardless of the possible benefits gained from associating with sibling shoals. The results reveal the ability of fish to discriminate their siblings during their early developmental stage and the overriding influence shoal size in the context of shoaling preference in P. sarana subnasutus.

Page(s): 583-586

Response of antioxidative and ethanolic fermentation enzymes in maize seedlings of tolerant and sensitive genotypes under short term waterlogging

Title: Response of antioxidative and ethanolic fermentation enzymes in maize seedlings of tolerant and sensitive genotypes under short term waterlogging

Authors: Chugh, Vishal; Gupta, Anil K; Grewal, Maninder S; Kaur, Narinder

Abstract: Fifteen days old seedlings of waterlogging tolerant (Parkash) and sensitive (Paras) maize genotypes were subjected to short term waterlogging (18 h) under field conditions. Activities of various antioxidative and anaerobic metabolism enzymes were investigated in leaf and root tissues. Superoxide dismutase (SOD) activity increased in leaf tissue while glutathione reductase (GR) activity was enhanced in leaf as well as root in both the genotypes. However, tolerant genotype had better induction capability of SOD and GR in roots in comparison with sensitive genotype. Catalase activity increased in roots of both genotypes. Waterlogging caused strong induction in alcohol dehydrogenase activity in the roots of Paras and Parkash under stress conditions. Aldehyde dehydrogenase activity was significantly increased only in roots of Parkash in response to waterlogging. In comparison with sensitive genotype, the tolerant genotype had low H₂O₂ and malondialdehyde content in roots under stress conditions. The present studies suggested that tolerant genotype had a greater protective ability due to higher induced activities of antioxidant and ethanolic fermentation systems than Paras.

Page(s): 577-582

Alkaline protease production, extraction and characterization from alkaliphilic Bacillus licheniformis KBDL4: A Lonar soda lake isolate

Title: Alkaline protease production, extraction and characterization from alkaliphilic Bacillus licheniformis KBDL4: A Lonar soda lake isolate

Authors: Pathak, Anupama P; Deshmukh, Kshipra B

Abstract: A bacterium producing an alkaline protease was isolated from the Lonar soda lake, Buldhana district (19°58' N; 76°31' E), Maharashtra, India. The most appropriate medium for the growth and protease production was composed of (g/L): casein 10; yeast extract 4; KH₂PO₄ 0.5, K₂HPO₄ 0.5 and CaCl₂0.5. The enzyme showed maximum activity with and without 5 mM Ca²⁺ at 70 and 60 ^oC, respectively. The enzyme retained 40 and 82% of its initial activity after heating for 60 min at 60 ^oC, in absence and presence of 5 mM CaCl₂respectively. The enzyme remained active and stable at pH 8-12, with an optimum at pH 10. The enzyme showed stability towards non-ionic and anionic surfactants, and oxidizing agents. It also showed excellent stability and compatibility with commonly used laundry detergents. Wash performance analysis revealed that enzyme could effectively remove blood stains. It also showed decomposition of gelatinous coating on X- ray film.

Page(s): 569-576