Acute effects of heat on neuropsychological changes and physiological responses under noise condition

To examine the effects of heat and noise individually and jointly on certain physiological responses and cognitive and neuromotor based functions, 12 male participants were tested under 6 experimental conditions which resulted by combining 3 levels of heat (25 degrees, 30 degrees and 35 degrees C) and 2 levels of white noise (70 and 100 dB). The experiment was carried out in a controlled climatic chamber following two 6 x 6 latin square designs. The results indicated elevations in heart rate, oxygen uptake and body temperature due to the independent effect of heat or the combined effects of heat and noise. The independent action of noise was found to be depressive on the first two responses. On the neuropsychological effects, the heat adversely affected the speed in card sorting (by design configuration) and digit symbol tests, and also the accuracy and error rate in the reasoning ability test. The noise caused performance improvements in critical flicker frequency (simultaneous) and in error rates in card sorting (by design configuration). The combined effects of heat and noise indicated higher error rates in card sorting (by face value), decreased accuracy in reasoning ability and improvements in performance in accuracy scores and error rates in digit symbol test.     

Isolation and cloning of a Azospirillum lipoferum locus that complements Escherichia coli proU mutant

Glycine betaine relieved sodium chloride-mediated inhibition of growth in Azospirillum lipoferum ATCC 29708. ³⁵S-methionine labelling of proteins after salinity up-shock revealed strong induction of a 30 kDa protein which cross-reacted with the anti-glycine betaine binding protein antibody from Escherichia coli. This suggested that A. lipoferum had a salinity-induced ProU-like high-affinity glycine betaine transport system. A genomic library of A. lipoferum ATCC 29708 was screened for the proU-like gene by complementation of a proU mutant of E. coli. Four recombinant cosmids, capable of restoring growth of the proU mutant on plates containing 600 mM NaCl and 1 mM glycine betaine were selected. Selected recombinant cosmids hybridized with a proU gene probe from E. coli. Complementation of E. coli proU mutant with the A. lipoferum genomic DNA was evident by the ability of proU mutant (containing selected recombinant cosmids) to grow on minimal medium supplemented with 600 mM NaCl and 1 mM glycine betaine.     

Complete Amino Acid Sequence of a Subunit from Rapeseed Protein

A subunit of molecular weight 18300 has been separated and isolated from seeds of Brassica campestris L. This subunit was cleaved by using cyanogen bromide, trypsin, Staphylococcus aureus V8 protease and chymotrypsin; the fragments obtained from enzymatlc and chemical cleavages were separated and isolated by polyacrylamide gel electrophoresis and gel filtration. The amino acid analyses were carried out. The complete amino acid sequence of the subunit containing 172 amino acid residues has been established by manual Edman method.     

DESICCATION AND STARVATION TOLERANCE OF ADULT DROSOPHILA: OPPOSITE LATITUDINAL CLINES IN NATURAL POPULATIONS OF THREE DIFFERENT SPECIES

Desiccation and starvation tolerance were measured along latitudinal transects in three Drosophilid species (Drosophila ananassae, D. melanogaster, and Zaprionus indianus) of the Indian subcontinent. In each case, significant latitudinal clines were observed; desiccation tolerance increased with latitude while starvation tolerance decreased. Such field observations suggest that desiccation and starvation tolerance are fitness related traits that are independently selected in nature and genetically independent. It was, however, difficult to relate these genetic changes with precise climatic variables, except winter temperature. The overall negative correlation between the two traits, which was evidenced in natural populations, contrasts with a positive correlation generally observed in various laboratory selection experiments and that also seems to exist between different species. These observations point to the difficulty of interpreting correlations among fitness-related traits when different evolutionary levels are compared, and also different sets of data, that is, field versus laboratory studies.     

Aluminum-mediated metabolic changes in rat serum and urine: a proton nuclear magnetic resonance study

The toxic effects of Al(3+) have been studied in 90-days AlCl(3) orally treated male albino rats (n = 7) using (1)H NMR spectroscopy-based metabolic profile of rat serum and urine, serum enzyme tests, behavioral impairment, and histopathology of kidney and liver. Metabolic profile of 90-days Al(3+)-treated rat sera showed significantly elevated levels of alanine, glutamine, beta-hydroxy-butyrate, and acetoacetate and significantly decreased level of acetone when compared with that of control rats. However, metabolic profile of 90-days Al(3+)-treated rat urine showed significantly decreased levels of citrate, creatinine, allantoin, trans-aconitate, and succinate and significantly increased level of acetate when compared to control rats. The overall perturbations observed in the metabolic profile of serum and urine demonstrate the impairment in the tricarboxylic acid cycle, liver and kidney metabolism, which was further reinstated by clinical chemistry and histopathological observations. Moreover, "in vivo" behavioral impairment has also been observed as the indication of aluminum neurotoxicity.     

Ion binding constants for gramicidin a obtained from water permeability measurements

Gramicidin A pores are permeable to water and small monovalent cations. For K, Rb, and Cs there is good evidence from conductances and permeability ratios that a second ion can enter a pore already occupied by another, but for Na this evidence is inconclusive and comparison of tracer fluxes and single channel conductances suggests that second ion entries are prohibited. Partly as a result of the complications of second ion entry there have been widely differing estimates for the dissociation constants for the first ion in the channel. Dani and Levitt (1981, Biophys. J. 35: 485–499) introduced a method for calculating ion binding constants from simultaneous measurements of water fluxes and membrane conductance. They found no evidence for second ion binding and calculated dissociation constants of 115 mm for Li, 69 mm for K, and 2 mm for Tl. It is shown here that the two-ion, four-state model predicts a dependence of water permeability on ion concentration that is difficult to distinguish from the predictions of block by a single ion. Using a modified technique that allows measurement of higher conductances, the first ion dissociation constants have been determined as 80 mm for Na, 40 mm for Rb and 15 mm for Cs. These values and those of Dani and Levitt fall in a smooth sequence. The dissociation constant for Cs is consistent with single channel conductances and flux ratios. There is a discrepancy between this constant for Na and the value, 370 mm, calculated from the single channel conductances and the assumption that a second ion cannot enter or affect an occupied pore. The dissociation constant for Rb is intermediate between those for K and Cs whereas tracer flux measurements (Schagina, Grinfeldt & Lev, 1983. J. Membrane Biol. 73: 203–216) have suggested that Rb interacts much more strongly with the channel than Cs.We should like to thank the National Grid plc, for the grant which supported K.-W.W., the Wellcome Trust for a visiting Fellowship for S.T. in Cambridge, and the Cambridge Society of Bombay which supported S.B.H. in Bombay.     

Proteomic Profiling of SupT1 Cells Reveal Modulation of Host Proteins by HIV-1 Nef Variants

Nef is an accessory viral protein that promotes HIV-1 replication, facilitating alterations in cellular pathways via multiple protein-protein interactions. The advent of proteomics has expanded the focus on better identification of novel molecular pathways regulating disease progression. In this study, nef was sequenced from randomly selected patients, however, sequence variability identified did not elicited any specific mutation that could have segregated HIV-1 patients in different stages of disease progression. To explore the difference in Nef functionality based on sequence variability we used proteomics approach. Proteomic profiling was done to compare the effect of Nef variants in host cell protein expression. 2DGE in control and Nef transfected SupT1 cells demonstrated several differentially expressed proteins. Fourteen protein spots were detected with more than 1.5 fold difference. Significant down regulation was seen in six unique protein spots in the Nef treated cells. Proteins were identified as Cyclophilin A, EIF5A-1 isoform B, Rho GDI 1 isoform a, VDAC1, OTUB1 and α-enolase isoform 1 (ENO1) through LC-MS/MS. The differential expression of the 6 proteins was analyzed by Real time PCR, Western blotting and Immunofluorescence studies with two Nef variants (RP14 and RP01) in SupT1 cells. There was contrasting difference between the effect of these Nef variants upon the expression of these six proteins. Downregulation of α-enolase (ENO1), VDAC1 and OTUB1 was more significant by Nef RP01 whereas Cyclophilin A and RhoGDI were found to be more downregulated by Nef RP14. This difference in Nef variants upon host protein expression was also studied through a site directed mutant of Nef RP01 _{(55AAAAAAA61)} and the effect was found to be reversed. Deciphering the role of these proteins mediated by Nef variants will open a new avenue of research in understanding Nef mediated pathogenesis. Overall study determines modulation of cellular protein expression in T cells by HIV-1 Nef variants.     

Effects of anthropogenic disturbance on plant diversity and community structure of a sacred grove in Meghalaya, northeast India

This study analyses the effects of anthropogenic disturbance on plant diversity and community attributes of a sacred grove (montane subtropical forest) at Swer in the East Khasi Hills district of Meghalaya in northeast India. The undisturbed, moderately disturbed and highly disturbed stands were identified within the sacred grove on the basis of canopy cover, light interception and tree (cbh 15 cm) density. The undisturbed forest stand had >40% canopy cover, >50% light interception and a density of 2103 trees per hectare, whereas the highly disturbed stand had <10% canopy cover, <10% light interception and 852 trees per hectare. The moderately disturbed stand occupied the intermediate position with respect to these parameters. The study revealed that the mild disturbance favoured species richness, but with increased degree of disturbance, as was the case in the highly disturbed stand, the species richness markedly decreased. The number of families of angiosperms was highest (63) in the undisturbed stand, followed by the moderately (60) and highly disturbed (46) stands. The families Rubiaceae, Asteraceae and Poaceae were the dominant families in the sacred forest. Rubiaceae was represented by 11, 14 and 10 species in the undisturbed, moderately disturbed and highly disturbed stands, respectively, whilst the family Asteraceae had 16 species in the moderately disturbed stand and 14 species in the highly disturbed stand. The number of families represented by a single species was reduced significantly from 33 in the undisturbed stand to 23 in the moderately and 21 in the highly disturbed stand. The similarity index was maximum (71%) between the undisturbed and moderately disturbed stand and minimum (33%) between the undisturbed and highly disturbed stands. The Margalef index, Shannon diversity index and evenness index exhibited a similar trend, with highest values in the moderately disturbed stand. In contrast, the Simpson dominance index was highest in the highly disturbed stand. There was a sharp decline in tree density and basal area from the undisturbed (2103 trees ha^–1 and 26.9 m² ha^–1) to the moderately disturbed (1268 trees ha^–1 and 18.6 m² ha^–1) and finally to the highly disturbed (852 trees ha^–1 and 7.1 m² ha^–1) stand. Density–girth curves depicted a successive reduction in number of trees in higher girth classes from the undisturbed to the moderately and highly disturbed stands. The log-normal dominance–distribution curve in the undisturbed and moderately disturbed stands indicated the complex and stable nature of the community. However, the short-hooked curve obtained for the highly disturbed stand denoted its simple and unstable nature.