Ecosystem aspects of arsenic poisoning: Human exposure to arsenic from food chain

Although the main source of arsenic to human body is ground water, the use of arsenic contaminated ground water for irrigation gives rise to the question whether arsenic uptake in crop plants could also be another potential pathway of human exposure to arsenic. Arsenic content in straw, grain and husk of rice is especially important as rice is the staple food for man and straw and husk have been used as cattle feed. It was estimated that the daily intake of arsenic in human body from rice (containing 0.40 mg As/kg, the highest concentration of arsenic found in the present experiment in treatment containing 40 mg As/kg soil) is 0.20 to 0.32 mg/day (as the average consumption of rice by the people above five years old is between 400 and 650 gm/day) whereas it is 0.20 mg/day from drinking water (as the recommended safe level arsenic in drinking water is 0.05 mg As/l for Bangladesh and the average intake of water by an adult is about four litres). This finding suggests that arsenic intake in human body through rice could be a potential pathway in addition to drinking water. Therefore, a hypothesis have been put forward that the human beings have not been suffering from arsenicosis only from drinking water but also from "Plant-Animal-Man" and some other food chain pathway

Towards developing a Healthcare Situation Monitoring Method for Smart City Initiatives: A Citizen Safety Perspective

Research in Smart City development has been proliferated over the past few years, which focused heavily on various supporting service sectors, such as healthcare. However, little effort has been made to design health surveillance support systems, which is also important for the advancement of public healthcare monitoring as an essential smart city initiatives. From an information system (IS) design perspective, this paper introduces a social media-based health surveillance supporting method, which can automatically extricates relevant online posts for health symptom management and prediction. We describe and demonstrate an IS design approach in this paper for hay-fever prediction solution concept based on Twitter posts. This concept can be applicable to fully functional solution design by relevant practitioners in this field

Effect of Different Levels of Protein Supplementation on Reproductive Performance of Rabbit Does Under Tropical Conditions

The study was conducted over a 125 days period with 150 does which were randomly assigned to three treatment groups of 50 does each. The does were fed one of the diets containing 13.17, 16.64 and 21.00% crude protein (CP) supplementation with ad libitum green grass (Hymenachne pseudointerrupta, CP=6.6%). Gestation period, litter size & litter weight ( at birth & weaning), individual pup weight at birth and weight gain up to weaning (28 d) did not differ (P>0.05) among the treatment groups. The pregnancy rate of does and mortality of pups up to weaning were significantly affected (P<0.05) among the treatment groups. The mean of the pregnancy rate was highest (100 %) in the group fed on 21.00% CP diet, while the number of pups alive up to weaning was highest (100 %) in the group fed on 13.17% CP diet. Based on these findings, the inclusion of 21.00% CP diet along with ad libitium green grass may be suggested for better reproductive performance of does under tropical conditions

Straighthead disease of rice (Oryza sativa L.) induced by arsenic toxicity

Straighthead disease is a physiological disorder of rice (Oryza sativa L.) characterized by sterility of the florates/spikelets leading to reduced grain yield. Though the exact cause of straighthead is unknown, a glass house experiment was conducted to investigate the effect of inorganic arsenic on straighthead disease in rice (Oryza sativa L.). BRRI dhan 29, a popular Bangladeshi rice strain, was grown in soils spiked with arsenic (prepared from sodium arsenate, Na2HAsO4·7H2O) at the rate of 10, 20, 30, 40, 50, 60, 70, 80 and 90 mg of As kg-1 and one control treatment was also run to compare the results. Although there may be some other soil physico-chemical factors involved, arsenic concentration was found to be closely associated with straighthead of rice. With the increase of soil arsenic concentration, the severity of straighthead increased significantly. Up to the 50 mg of As kg-1 soil treatments, the severity of straighthead incidences were not prevalent. Straighthead resulted in sterile florets with distorted lemma and palea, reduced plant height, tillering, panicle length and grain yield. Straighthead caused approximately 17-100% sterile florates/spikelets formation and about 16-100% loss of grain yield. Straighthead also causes the reduction of panicle formation and panicle length significantly (p < 0.01). In the present study, panicle formation was found to be reduced by 21-95% by straighthead. © 2007 Elsevier B.V. All rights reserved

Effects of Hepatic Ischemia-Reperfusion Injury on the P-Glycoprotein Activity at the Liver Canalicular Membrane and Blood-Brain Barrier Determined by In Vivo Administration of Rhodamine 123 in Rats

Purpose To investigate the effects of normothermic hepatic ischemia-reperfusion (IR) injury on the activity of P-glycoprotein (P-gp) in the liver and at the blood-brain barrier (BBB) of rats using rhodamine 123 (RH-123) as an in vivo marker. Methods Rats were subjected to 90 min of partial ischemia or sham surgery, followed by 12 or 24 h of reperfusion. Following intravenous injection, the concentrations of RH-123 in blood, bile, brain, and liver were used for pharmacokinetic calculations. The protein levels of P-gp and some other transporters in the liver and brain were also determined by Western blot analysis. Results P-gp protein levels at the liver canalicular membrane were increased by twofold after 24 h of reperfusion. However, the biliary excretion of RH-123 was reduced in these rats by 26%, presumably due to IR-induced reductions in the liver uptake of the marker and hepatic ATP concentrations. At the BBB, a 24% overexpression of P-gp in the 24-h IR animals was associated with a 30% decrease in the apparent brain uptake clearance of RH-123. The pharmacokinetics or brain distribution of RH-123 was not affected by the 12-h IR injury. Conclusions Hepatic IR injury may alter the peripheral pharmacokinetics and brain distribution of drugs that are transported by P-gp and possibly other transporters

Effects of Short-Term Portacaval Anastomosis on the Peripheral and Brain Disposition of the Blood-Brain Barrier Permeability Marker Sodium Fluorescein in Rats

Contradictory results have been reported with regard to the effects of various models of hepatic encephalopathy on the blood-brain barrier (BBB) permeability, which may be due partly to the use of brain concentrations of BBB markers without attention to their peripheral pharmacokinetics. The purpose of the current study was to investigate the effects of short-term portacaval anastomosis (PCA), a type B model of hepatic encephalopathy, on the peripheral pharmacokinetics and brain distribution of sodium fluorescein (FL), which is a small molecule marker of BBB passive permeability. A single 25 mg/kg dose of FL was administered intravenously to 10-day PCA and sham-operated rats, and serial blood and bile (0-30 min) and terminal (30 min) brain samples were collected, and the concentrations of FL and its glucuronidated metabolite (FL-Glu) were measured by HPLC. Additionally, the free fractions of FL (fu) in all the plasma samples were determined, and the effects of bile salts on fu were investigated in vitro. Passive permeability of BBB to FL was estimated by brain uptake clearance (Kin) based on both the brain concentrations of FL and plasma concentrations of free (unbound) FL. PCA caused a 26% increase in the fu of FL in plasma, which was due to competition of bile acids with FL for binding to plasma proteins. Additionally, PCA reduced the biliary excretion of FL-Glu by 55%. However, free Kin values (μl/min/g brain) for the sham (0.265 ± 0.034) and PCA (0.228 ± 0.038) rats were not significantly different. It is concluded that whereas 10-day PCA alters the peripheral pharmacokinetics of FL, it does not significantly affect the BBB permeability to the marker

Cu-Doping Effects in CdI2Nanocrystals: The Role of Cu-Agglomerates

Cu-doping effects in CdI2nanocrystals are studied experimentally. We use the photostimulated second harmonic generation (PSSHG) as a tool to investigate the effects. It is found that the PSSHG increases with increasing Cu content up to 0.6% and then decreases due to the formation of the Cu-agglomerates. The PSSHG for the crystal with Cu content higher than 1% reduces to that for the undoped CdI2crystal. The results suggest that a crucial role of the Cu-metallic agglomerates is involved in the processes as responsible for the observed effects

Arsenic accumulation in rice (Oryza sativa L.) varieties of Bangladesh: A glass house study

A glass house study was conducted to investigate the accumulation of arsenic in tissues of five widely cultivated rice (Oryza sativa L.) varieties of Bangladesh namely BRRI dhan 28, BRRI dhan 29, BRRI dhan 35, BRRI dhan 36, BRRI hybrid dhan 1. Arsenic concentrations were measured in straw, husk and brown and polish rice grain to see the differential accumulation of arsenic among the rice varieties. The results showed that the concentrations of arsenic in different parts of all rice varieties increased significantly (p BRRI dhan 35 > BRRI dhan 36 > BRRI dhan 29 > BRRI hybrid dhan 1. The order of arsenic contents in tissues of rice was: straw > husk > brown rice grain > polish rice grain. © 2007 Springer Science+Business Media B.V