Impact of Microcystin-LR on Liver Function Varies by Dose and Sex in Mice

Microcystin (MC) exposure is an increasing concern because more geographical locations are covered with cyanobacterial blooms as eutrophication and bloom-favoring environmental factors become more prevalent worldwide. Acute MC exposure has been linked to gastrointestinal distress, liver toxicity, and death in extreme circumstances. The goal of this study was to provide an accurate and comprehensive description of MC-LRs impacts on liver pathology, clinical chemistry, and gap junction intercellular communication (GJIC) in CD-1 male and female mice. Mice were exposed to 0, 3000, and 5000/4000 µg/kg/day MC-LR, daily for 7 days, and were necropsied on Day 8. Blood samples for clinical chemistry analysis were processed to serum, while liver sections were fixed for histopathology or evaluated for GJIC using fluorescent cut-load dye. Results show a dose-dependent relationship with MC-LR exposure and hepatocellular hypertrophy, degradation, and necrosis. Clinical chemistry parameters alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, and cholesterol increased significantly in MC-LR exposed mice. Clinical chemistry parameter analysis showed significantly increased susceptibility to MC-LR in females compared to males. Changes in GJIC were not noted, but localization of hepatotoxicity near the central veins and midlobular areas was seen. Future toxicity studies involving MCs should consider response differences across sexes, differing MC congeners, and combinatorial exposures involving other cyanotoxins.

Study of Physico-Chemical Parameter of Deepang lake in Pokhara Valley, Nepal

The present study on Physico-chemical Parameter of Deepang lake in Pokhara valley, Nepal was performed for six months from August 2009 to January 2010. The study included various physico-chemistry parameter like transparency, temperature, PH, free carbondioxide, dissolve oxygen and total alkalinity. The maximum transparency 2.5 m was recorded in January and minimum 1.4 m in August. In other months the transparency were slightly changeable. The maximum temperature 25.6°C was recorded in August and minimum 17.7°C in January. The temperature gradually decreased. The PH values were found mostly alkaline and were generally between 6.7 and 7.5 during the investigation period. The highest PH 7.5 was recorded in January and lowest 6.7 in August. Dissolved oxygen value gradually increased from 6.4 mg/l in August to 8.7 mg/l in January. The concentration of free CO2 ranged between 1.8 mg/l and 5.6 mg/l during the investigation period. The maximum value was 5.6 mg/l in August and 1.8 mg/l in January. The maximum alkaline value 114 mg/l was recorded in January and minimum value 105 mg/l in August. All these Physico-chemical parameter meet WHO Standard of Water Quality. Janapriya Journal of Interdisciplinary Studies Vol. 2, No.1 (December 2013), page: 90-95

The Characteristic Dissolution and Physical Chemistry Parameter of Synthetic Pyromorphite

The Dissolution of Synthetic Pyromorphite was Studied at 25°C in a Series of Batch Experiments. in Addition, the Aqueous Concentrations from the Batch Dissolution were Used to Calculate the Solubility Product and Free Energy of Formation of Pyromorphite. the Results of the Fourier Transform Infrared Spectroscopy Analyses Indicated that the Synthetic, Microcrystalline Pyromorphite with Apatite Structure Used in the Experiments has Not Changed after Dissolution. the Mean KspValue was Calculated for Pb5(PO4)3Cl of 10-78.31 at 25°C; the Free Energy of Formation ΔGf0[Pb5(PO4)3Cl] was-3756.82kJ/mol.

Ion Export from a Small British Columbia Watershed After Forest Harvesting

A small coastal British Columbia lake was monitored before and after approximately 11% of the watershed was logged. There was an increase in the concentrations of most of the ions measured in the lake water after logging. Peak concentrations occurred two to three years after logging and most ions returned to background concentrations in five to eight years. Two methods were used to estimate the increased export of ions resulting from the forest harvesting. The first method used a water chemistry / hydrology watershed model, and the second used the changes in lake concentrations to calculate watershed input. The changes in ion concentrations and export varied with model and chemistry parameter with a change from a 1.3- to 4.2-fold increase for major cations and anions like calcium, magnesium, sodium, and chloride, to a 5- to 35-fold increase in ion export for nitrate and ammonium. The export of nitrogen from the watershed has implications for both water quality and future forest productivity. The measurement of lake ion increase is proposed as a general means of evaluating longer term change or disturbance in a watershed.

Ictioplancton en la zona portuaria de Limón, Costa Rica

Four sampling stations were set 200-500m off Limon Port, Costa Rica, at an average depth of 20 m. From October 1996 to May 1997 horizontal subsuperficial trawls were done for 12 minutes at a speed of about 2KmIh, with a 1 OOO¡.tm plancton neto A total of 28 samples were processed and 104 physieal-chemistry parameter measurements were taken. Average salinity was 30.1 ± 3.7 and dissolved oxygen 6.9 ± 0.6 mg 1-1 reflecting good aeration throughout the sampling périod. This suggests good mixture and a highly dynamic hydrography. Temperature showed no drastic variations (28.0 ± 1.7 OC), possibly because of the constant mixing with shallow water. The highest larval counts were for November and early January and inelude families common to reefs and estuaries (BaJistidae, Lutjanidae) and to coastal areas (Centropomidae, Gerreidae, Haemulidae, Carangidae, Engraulidae, Hemiramphidae, and representative Pleuronectiforrnes) existing in a common area.