Lead distribution in rats following respiratory exposure to lead-contaminated soils

Two preliminary experiments were performed to explore the use of an intratracheal instillation technique as a cost-effective method of determining the biokinetics of lead (Pb) following respiratory exposure to Pb-contaminated soils. A novel intratracheal instillation procedure was refined and used to deliver a defined dose of Pb-contaminated soil or PbAc to the lower respiratory tract of rats. In the first experiment, rats were sacrificed at numerous time intervals post-dosing, and liver, kidney, blood, and bone tissues were collected for Pb analysis. In the second experiment, rats were dosed with Pb-contaminated soil or PbAc via intratracheal instillation or gastric gavage. All rats were sacrificed 96 h after dose administration and tissues were collected for lead analysis. Data from these experiments indicate Pb is well-absorbed following intratracheal instillation of Pb-contaminated soil, and the intratracheal instillation technique could be used as a cost effective method for exploring the biokinetics of Pb in Pb-contaminated soils following respiratory tract exposure.     

Levels of plasma B-esterases and glutathione-S-transferase activities in three South American toad species

We determined the normal levels of butyrylcholinesterase (BChE), carboxylesterase (CbE), and glutathione S-transferases (GST) activities in three South American toad species in order to establish reference values for field pesticide monitoring purposes. Interspecies variations in B-esterase and GST activities were examined according to body mass. In addition, comparative inhibition of BChE and CbE activities using malaoxon, and chemical reactivation of malaoxon-inhibited BChE activity using pyridine-2-aldoxime methochloride (2-PAM) were investigated. Bufo fernandezae had average activity values for BChE: 17.31 mmol min^?1 ml^?1; CbE: 621.49 nmol min^?1 ml^?1 and GST: 1.94 mmol min^?1 ml^?1 while B. arenarum enzymatic average activities were BChE: 9.51 mmol min^?1 ml^?1; CbE: 270.07 nmol min^?1 ml^?1, and GST: 1.59 mmol min^?1 ml^?1; finally Bufo schneideri had enzymatic mean values of BChE: 2.08 mmol min^?1 ml^?1; CbE: 301.95 nmol min^?1 ml^?1, and GST: 1.60 mmol min^?1 ml^?1. Moreover, we found an allometric relationship between plasma BChE and CbE activities and body size for the three toad species. We suggest that B. fernandezae would be the species with a higher tolerance capacity to organophosphorous insecticides compared to the other toad species, while B. schneideri may be the most vulnerable toad species to field pesticide exposure, although some other factors (e.g., brain AChE sensitivity or pesticide metabolism by phosphotriesterases) should be also taken into account. The malaoxon-inhibited BChE activity of the three toad species was reactivated in the presence of 2-PAM, and it is recommended as a specific and sensitive methodology in the assessment of field exposure to OP insecticides together to compare BChE activity levels between OP-exposed and nonexposed individuals.     

Interaction of alcohol and kola nut on brain sodium pump activity in Wistar rats

The effect of interaction of alcohol and kola nut on sodium pump activity was studied in Wistar rats. Thirty Wistar rats were divided into six groups of five rats per group. Control received a placebo (4 mL of distilled water). Groups 2–6 were treated for a period of 21 days with 10% (v/v) alcohol, 50 mg caffeine/kg, 50 mg kola nut/kg, or a combination of 10% (v/v) alcohol + 50 mg kola nut/kg, or 10% (v/v) alcohol + 50 mg caffeine/kg, respectively. One day after the final exposure, brains were harvested and several biochemical parameters examined including activities of total ATPase, ouabain-insensitive ATPase, ouabain sensitive ATPase (Na⁺–K⁺-ATPase) and levels of nonenzymatic breakdown of ATP and inorganic phosphate (P_i) released. Results showed that the essential enzyme of the brain responsible for neuronal function, Na⁺–K⁺-ATPase, was inhibited by alcohol–kola nut co-administration relative to control, resulting in a decreased ATP production, ion transport and action potential, leading to loss of neuronal activities.     

Measurement of residues of benomyl and mancozeb pesticides in shrub and nonshrub cucumbers sampled from different regions of Mazandaran province (Iran)

Farmers use mancozeb against cucumber pests, such as Perono spoxa, in large amounts without consideration of potential chronic human health hazards resulting from pesticide accumulation in food and fruits. Considering the necessity of food for humans and importance of fruit in daily diet, as well as the determination of pesticide residues in food and fruits as mandated by WHO and FAO, the residues benomyl and mancozeb, the most prominently used pesticides in Iran, were measured. In this study cucumbers from 76 sample regions were used. Data showed that the amounts of benomyl was related to the type of cucumber in the regions, but there was no significant relationship between the amount of mancozeb and type of cucumber.     

Automated indirect fluoride determination by ICP-OES using discontinuous-flow analysis

An automated method for the indirect determination of fluoride by inductively coupled plasma atomic emission spectrometry using discontinuous-flow analysis has been developed. A modified flow injection analysis system was used for sample preparation. The method is based on the determination of excess cerium(III) ion after precipitation of CeF₃. Separation of the precipitate is performed online on a syringe membrane filter that is cleaned each analysis cycle by 1 M nitric acid, ensuring a long life-time for the filter. As a result of the short reaction time, a detection limit of 9.5 mg L^?1 was obtained. The precision (RSD) of the proposed method is 1.02% at fluoride concentration of 28 mg L^?1. The applicability of the technique for groundwater monitoring of fluoride-contaminated area is demonstrated.     

Evaluation of vitamin E and calcium effects on fluoride toxicity-induced fertility impairment

Chronic fluoride (Fl) toxicity is a serious public health problem globally where drinking water contains more than 1 ppm of Fl. Sodium fluoride (NaF) produced male reproductive system toxicity. The aim of the present study was to evaluate the amelioration of Fl toxicity-induced fertility impairment by vitamin E and calcium during the withdrawal period. The study was carried out on 70 adult male albino rats divided into five main groups: group I control; subdivided into group Ia (maintained on standard diet and water ad libitum for 60 days) and group Ib (maintained on standard diet and water ad libitum for 120 days), group II was administered NaF and subdivided into group IIa (administered NaF for 60 day and sacrificed) and group IIb (administered NaF for 60 day then maintained on standard diet and water ad libitum for a further 60 days), and treated groups III, IV, and V were administered NaF. Rats were maintained during withdrawal from NaF, on vitamin E (10 mg kg^?1 day^?1 for 60 days), calcium (50 mg kg^?1 day^?1 orally for 60 days), and both vitamin E and calcium, respectively. The duration of NaF administration was 60 days at a dose 20 mg kg^?1 day^?1 for all treated groups. The following parameters were determined: body and organ weights, sperm motility, sperm morphology, sperm viability, fertility test, and hormone assays: testosterone, in vitro testosterone production, luteinizing hormone, and follicular stimulating hormone. The combined administration of vitamin E and calcium during withdrawal from NaF showed significant improvement from chronic FL-induced toxicity on male reproductive organs.     

An assessment of the air pollution data from two monitoring stations in Kuwait

This article assesses the air pollution data from two monitoring stations in Kuwait. The measurements cover major pollutants, i.e., CO, CO₂, methanated and non-methanated hydrocarbons, NO _x , SO₂, O₃, and particulate matter (PM10). The data also includes meteorological parameters, i.e., solar intensity, temperature, wind speed, and wind direction, and has been collected over a period 4 years, from 2001 to 2004. Data analysis includes the assessment of annual hourly averages and 1-h maxima. Typical pollutant concentration trends, similar to those previously reported for Kuwait and for other locations around the world, are observed except for particulate matter measurements, which have higher values because of proximity to the desert. Emissions of nitrogen oxides show a consistent increase over the years. This is caused by the increase in the number of motor vehicles and the expansion in power generation and industrial activities. The data collected is a subset of the air quality criteria, as defined by the US EPA (United States Environmental Protection Agency).     

Toxicological effects of mouse diet contaminated with tributyltin on the immune and neurological systems of C57BL/6 mice

Organotin compounds, widely used as antifouling agents, are known to bioaccumulate in the food chain. Among organotin compounds, tributyltin (TBT), a toxic and widespread contaminant, has become a serious factor in environmental pollution and is suspected of being immunotoxic in animals. The purpose of this study was to assess the effects of 80 µg of TBT per kilogram of body weight (kg bw), provided in food, on the immune and neurological systems of C57Bl/6 mice. Data showed that TBT increased the proliferation of T and B lymphocytes in both adult and juvenile female and juvenile male mice, but that it decreased the proliferation of both T and B lymphocytes in adult male mice. The macrophages activity in female and male juvenile mice was higher than in adults of both sexes. The natural killer cytotoxic activity was also increased in juvenile and adult males and females compared to the control groups. In the brain, we observed the presence of TBT in the hippocampus, the striatum, the cortex, and the cerebellum in both the male and female groups. The highest levels were observed in the cortex of females and males, while the lowest levels were found in the cerebellum. TBT also induced an increase in the levels of the antioxidant glutathione (GSH) in the striatum, the hippocampus and in cortical structures but not in the cerebellum where the levels of TBT are lower. Our findings indicate that TBT modulated the immune and nervous systems causing endocrine and nervous perturbations.     

Biochemical assessment of lead,phenol, and benzene-contaminated water on the heart and blood of Albino rats

A study was performed to evaluate the effect of contaminated water on the tissues of Rattus novergicus (albino rats). Test rats were given water contaminated with lead (0.015 µg L^?1 tap water), phenol (0.05 mL L^?1 tap water), and benzene (0.05 mL L^?1 tap water), while control rats were given tap water over a period of 65 days after which the activity of selected enzymes of the heart and serum was assayed, and hematological parameters and serum lipid profiles were also determined. Generally, a significant (p < 0.05) drop in the activity of the enzymes was observed in the heart of test rats relative to the control rats. However, the serum activities increased significantly in the test group compared to the control group (p < 0.05). The concentrations of serum cholesterol, low-density lipoprotein (LDL), and triglycerides of the test rats were found to be significantly higher than those of the control rats (p < 0.05). Concentrations of hemoglobin, red blood cell count, and packed cell volume of test rats were observed to be significantly lower than those of the control rats (p < 0.05). The experimental results indicated that consumption of water contaminated with lead, phenol, and benzene may damage the heart, increase the risk of atherosclerosis as reflected by the serum lipid profile, and anemia as suggested by abnormal hematological properties.     

Gulf War agents trigger discrete transcriptional changes in human neuronal cells

Reports on Gulf War illness (GWI) implicated the use of the pesticide permethrin (PER), and the insect repellent N,N-diethyl-m-toluamide (DEET), in its etiology, as well as pyridostigmine bromide (PB), which was given as a prophylactic treatment against nerve agent exposure. Using Affymetrix microarrays the genomic response of human neuronal SHSY-5Y cells to 10 days of exposure to these agents was characterized and profiles of gene modulation unique to each treatment were demonstrated. In particular, a significantly greater impact of PER was observed compared to the other treatments. The Ingenuity Pathway Analysis knowledgebase was used to analyze the genomic datasets and attribute functional consequences to the effects of related genes, which were significantly up- or down-regulated in response to different treatments. Canonical pathways shown to be significantly modulated at the genomic level in response to exposure included cellular mechanisms, which might contribute to the clinical presentation in GWI patients and thus be targeted for further investigation as potential targets for therapeutic intervention.