In vivo effects of trivalent and hexavalent chromium on renal and hepatic atpases of a freshwater teleost Anabas scandens

The in vivo toxic effect of trivalent and hexavalent chromium (25 mg/L) on the renal and hepatic tissue ATPases of an edible teleost Anabas scandens was studied. In an exposure span of 30 days Na⁺-K⁺ ATPase activity exhibited a progressive inhibition in the kidney, but marked inhibition in Na⁺-K⁺ ATPase activity was observed in the liver. Mg²⁺ ATPase activity, however, exhibited an elevation on early exposures, with a later inhibition.     

Methyl farnesoate stimulates testicular growth in the freshwater crab Oziotelphusa senex senex fabricius

 The influence of methyl farnesoate (MF) on testicular growth in the fresh water crab Oziotelplusa senex senex was studied. MF stimulated testicular growth as evidenced by increased testicular weight, testicular index and testicular follicle diameter in MF injected crabs and provides evidence that MF acts as a male reproductive hormone in crustacea. Received: 25 August 1998 / Accepted: 18 February 1999     

Study of carbohydrate metabolism in selected tissues of freshwater mussel, Lamellidens marginalis under copper sulphate toxicity

Sublethal toxicity of copper sulphate on carbohydrate metabolism was studied in selected tissues of freshwater mussel, Lamellidens marginalis. Levels of glycogen and pyruvic acid decreased while lactic acid showed an increase. Activities of LDH, SDH and MDH decreased while G-6-PDH activity increased. There appears to be a shift in the carbohydrate metabolism from aerobic to anaerobic type due to toxicity of copper.     

Modulations in the levels of respiration and ions in carp Cyprinus carpio (L.) exposed to cypermethrin

This paper reports an investigation of the sublethal toxicity of cypermethrin (20 µg/l) on the levels of respiration and selected ions in tissues of carp (Cyprinus carpio L.). A significant decrease in O ₂ consumption and ions was observed in gill, brain, liver and muscle tissues of cypermethrinexposed fish. The decreased rate of O ₂ consumption may be due to inhibition of oxidative enzymes during cypermethrin stress.     

In vitro antioxidant and antibacterial activities of certain 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino}-indolin-2-one derivatives

A new series of 5- or 7-substituted 3-{4-(5-mercapto-1,3,4-oxadiazol-2-yl)phenylimino}-indolin-2-one derivatives were screened for in vitro antioxidant and antimicrobial activities. The results of this study revealed that all synthesized compounds were significantly scavenged DPPH free radicals in a concentration-dependant manner. The IC₅₀ values of all test compounds were found to be between 18.34 and 50.54?µM. All compounds significantly inhibited growth of bacteria and most of the minimum inhibitory concentration values were between 20 and 100?mg?mL^?1 indicating potent to moderate antibacterial activity. In conclusion, 3-{4-(5-mercapto-1,3,4-oxadiazole-2-yl)phenylimino)-5 or 7-substituted indolin-2-ones derivatives exhibited moderate antioxidant and antimicrobial activities.     

Interaction effects of insecticides on microbial populations and dehydrogenase activity in a black clay soil

Three insecticides, monocrotophos, quinalphos, and cypermethrin, were applied at 0, 5, 10, and 25 microg g(-1) either singly or in combination to a black clay soil to investigate their effects on the soil microflora and dehydrogenase activity. All three insecticides significantly enhanced the proliferation of bacteria and fungi and the soil dehydrogenase activity even at the highest level of 25 microg g(-1). Monocrotophos or quinalphos in combination with cypermethrin at tested levels interacted significantly to yield additive, synergistic, and antagonistic responses toward bacteria and fungi and dehydrogenase activity in soil. Antagonistic interactions were more pronounced toward soil microflora and dehydrogenase activity when the two (monocrotophos or quinalphos + cypermethrin) insecticides were present together in the soil at highest level (25 + 25 microg g(-1)), whereas synergistic or additive responses occurred at lower level with the same combination of insecticides in soil.     

Ambient Air Quality Status in Raniganj-Asansol Area, India

This investigation presents the assessment of ambient air quality with respect to suspended particulate matter (SPM), sulphur dioxide (SO₂) and oxides of nitrogen (NO_X) at four sites (RGC, SRS, BBC and BCC) in the Raniganj-Asansol area in West Bengal, India. Ambient air was monitored with a sampling frequency of twenty four hours (3 × 8 hours) at each site on every alternate day (3 days a week) covering a period of one year. A total of 429 samples were collected from RGC, 429 from SRS and 435 each from the BBC and BCC sites. Meteorological parameters such as temperature, relative humidity, wind-speed and wind-direction were also recorded simultaneously during the sampling period. Monthly and seasonal variation of these pollutants have been observed and recorded. The annual average and range values have also been calculated. Results of the investigation indicates that the 95th percentile values of SPM levels exceed the limits (200 g m^-3) at RGC, SRS and BBC sites and is within the limit of 500 g m^-3 at the BCC sites. The 95th percentile values of SO₂ levels did not exceed the reference level at any of the monitoring stations. The 95th percentile values of NO_X are found to be exceeding the limit (80 g m^-3) at RGC, SRS and BBC sites but is within the prescribed limit of 120 g m^-3 at the BCC site. Further, it has been observed that the concentrations of the pollutants are high in winter in comparison to the summer or the monsoon seasons. Results of the investigation indicates that industrial activities, indiscriminate open air burning of coal by the local inhabitants for cooking as well as coking purposes, vehicular traffic, etc. are responsible for the high concentration of pollutants in this area.     

Isolation of coliphages specific to enterotoxigenic E. coli (ETEC)

Bacteriophages specific to Enterotoxigenic E. coli (ETEC) are reported for the first time. Out of 15 isolated phages only 10 were specific to strains of ETEC. All ten phages of dsDNA could be grouped into three different genotypes based on their RAPD patterns observed and it is likellly that they belong to only 3 different strains. The three phages yielded clear plaques on 10 strains of ETEC within 4-6 h at 37 degrees C.