Interspecific variation of heavy metal concentrations in the different tissues of tropical intertidal gastropods from Malaysia

The present study aims to determine the concentrations of Cd, Cu, Fe, Ni, Pb, and Zn in the different tissues of five species of tropical intertidal gastropods from Malaysia. Each of the species have organs/tissues that highly accumulated certain metals. For Cu, the mantles of Cerithidea obtusa, Pugilina cochlidium, and Murex trapa; and the digestive caeca of Thais sp. and Chicoreus capucinus highly accumulated Cu. The shells of Chi. capucinus and M. trapa, the digestive caeca of P. cochlidium, and the digestive glands of Thais sp. and Chi. capucinus highly accumulated Cd. The tentacles and the digestive caeca of Cer. obtusa and P. cochlidium, respectively, highly accumulated Zn, the digestive glands of Thais sp., Chi. capucinus, and M. trapa also highly accumulated Zn. The shells of most of the gastropods accumulated high levels of Pb and Ni. The opercula of most of the gastropods, besides the digestive glands for Thais sp., accumulated high levels of Fe. The present study on interspecific variations of heavy metals in gastropods provided information on differences of metal distributions in the different tissues, which could be useful in proposing potential tissues as better biomonitoring tools of heavy metal bioavailabilities in the coastal waters of Peninsular Malaysia.     

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.     

The status of heavy metal levels in a Ramsar site,Kuala Gula bird sanctuary: the impact of the anthropogenic inputs

Distributions of Cd, Cu, Pb, and Zn in the surface sediments from two sites of the Kuala Gula Bird Sanctuary, Malaysia were monitored for a period of 6 months from October 2006 to March 2007. In December 2006, the concentration of Zn in one location was significantly (p??1) than the other metals at both sites, but in the oxidizable organic fraction it was highest at both sites during October; with mean concentrations of 18?mg?kg^?1 at both locations. In the acid-reducible fraction, high concentrations of Pb (2.3?mg?kg^?1) were detected at station 2 in February 2007, being highest among all four metals at both stations. The acid-reducible fraction found in Pb ranged from 0.10% to 3.1% in both stations. Percentages ranging from 51% to 96% were observed for all four metals in the resistant fraction throughout the sampling period. These results indicate low contributions from anthropogenic sources. The findings constitute a baseline data archive for future reference.     

Pharmacokinetics of [14C]-atrazine in rhesus monkeys,single-dose intravenous and oral administration

This is the first study regarding the pharmacokinetics of [¹⁴C]-atrazine conducted with rhesus monkeys. The animals received one dose (0.25 mg) intravenously (IV) or three doses (1, 10, or 100 mg) orally. Plasma, urine, and feces were collected at defined times up to 7 days post-dosing. Sample radioactivity was measured to determine the mass equivalent. IV administered [¹⁴C]-atrazine disappeared rapidly from blood, with an elimination half-life of about 5.5 ± 1.1 h. The pharmacokinetic profiles of [¹⁴C]-atrazine following oral administration at the three dose levels show that kinetic parameters such as AUC and C _max are linearly correlated with the dose. Seven days after dosing, urinary and fecal excretion of [¹⁴C]-atrazine reached 99% of total administered dose in the IV group and 91–95% in the three oral dose groups. In the IV-administered monkeys, approximately 85% of the dose was excreted in urine and 12% in feces. In three oral dose groups, urinary and fecal radioactivity recoveries approximated 57% and 21%, 58% and 25%, and 53% and 35%, respectively. More than 50% of the total urinary excreted radioactivity was found within the first 24 h after dosing. In conclusion, the principal elimination of [¹⁴C]-atrazine, IV and orally administered, is via urine. The oral bioavailability was 60% or higher. There was a significant linear correlation between administered oral dose and plasma concentration. Overall oral dose accountability ranged from 91% to 95%. Data generated may be useful in the risk assessment of human exposure to environmental atrazine contamination.     

Early murine immune responses from endotracheal exposures to biotechnology-related Bacillus strains

An immunology-based in vivo screening regime was used to assess the potential pathogenicity of biotechnology-related microbes. Strains of Bacillus cereus (Bc), Bacillus subtilis (Bs), Bacillus thuringiensis (Bt), and Bt commercial products (CPs) were tested. Balb/c mice were endotracheally instilled with purified spores, diluted CP, or vegetative cells (VC) (live or dead). Exposed mice were evaluated for changes in behavioral and physical symptoms, bacterial clearance, pulmonary granulocytes, and pulmonary and circulatory pyrogenic cytokines (interleukins (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α), as well as acute phase biomarkers (fibrinogen and serum amyloid A). Except for some differences in clearance rates, no marked effects were observed in mice exposed to any spore at 10⁶ or 10⁷ colony forming units (cfu). In contrast, live Bc or Bt VCs (10⁵ or 10⁶?cfu) produced shock-like symptoms (lethargy, hunched appearance, ruffled fur, and respiratory distress), and 11–200-fold elevations in pyrogenic cytokines at 2-h post-exposure. In the study, 4-h effects included increased lethargy, ocular discharge, and 1.5–4-fold rise in circulatory acute phase markers, but no indications of recovery. Bs VC did not produce any changes in symptoms or biomarkers. After 2 or 4?h of exposure to dead VC, increases of only plasma IL-1β and TNF-α (4.6- and 12.4-fold, respectively) were observed. These findings demonstrate that purified spores produced no marked effects in mice compared to that of metabolically active bacteria. This early screening regime was successful in distinguishing the pathogenicity of the different Bacillus species, and might be useful for assessing the relative hazard potential of other biotechnology-related candidate strains.     

Evaluation of reproductive and developmental toxicity of cypermethrin in male albino rats

The ever-increasing use of pesticides in the agricultural and public health has become a major cause of sterility in human and various other animals particularly in males. This study was sought to screen the toxic impacts of cypermethrin (synthetic pyrethroid) on reproduction and development. Twenty-four Wistar male rats divided into four groups were orally administered cypermethrin of daily doses 50, 75, or 100 mg?kg^?1 bwt per day for 45 days; and for developmental toxicity, 12 female rats were separated into two groups. Maternal rats (experimental) were administered cypermethrin (100?mg?kg^?1) by gavage daily from 6th to 17th day of gestation, and the control group was dosed only vehicle (olive oil). The body weights, fertility index, biochemical, enzymatic, hormonal, and histopathological parameters were the criteria used to evaluate the toxicity of cypermethrin. Study showed significant decline in the weight of testes, epididymises, seminal vesicles, and ventral prostate, and reduction in sperm counts both in epididymises and testes in chemical-treated animals. Pre- and post- fertility test showed 50%, 80%, and 100% negative results after treatment. A significant degenerative reduction in testicular glycogen and sialic acid was also noted. In contrast, protein and cholesterol levels of testes were significantly increased. In addition, acid phosphatase activity was significantly increased, while alkaline phosphatase, testosterone, leutinizing hormone (LH), and follicle stimulating hormone (FSH) levels were diminished. Histology of testes showed degenerative changes in seminiferous tubules. Cypermethrin exposure during gestation produced adverse effects markedly in females and fetuses.     

Male reproductive toxicity of organophosphorous compounds: a review

Fertility is declining in many countries and there has been substantial interest in the potential adverse effects of exposure to environmental hazardous chemicals, including pesticides on male reproduction. Organophosphorous compounds (organophosphates, OP) constitute a heterogeneous category of chemicals specifically designed for the control of pests or plant diseases. OP are known to produce reproductive toxicity, resulting in a decrease in the fertility levels of humans and animals. This review article mainly focused on toxicity of some OP such as acephate, chlorpyrifos, diazinon, dimethoate, fenitrothion, malathion, and monocrotophos especially dealing with reproductive toxicity in males. Furthermore, this review deals with mode of action and clinical syndromes of OP. Considerable lab studies on animals concluded that OP produce adverse effects on male reproductive system.     

Exploring the diversity of neem bioactives as eco-benign pesticides: a reappraisal

Biological activity of neem seeds, leaves and bark is well-established as feeding deterrent and growth disrupter against insects and other arthropods. Neem is a valuable natural pesticide with low toxicity for vertebrates. However, it has not yet achieved a prominent place among pesticides due to its unstability. Recent studies have focused on newer formulations like microencapsulation, inclusion complexes, microemulsion, and granular formulations to enhance efficacy shelf life. Several studies have been undertaken on the effects of neem on predator, parasitoids, and other beneficial organisms as well as impact on the environment. Biotechnological interventions have been carried out for mass production of the active molecule. Once stable formulations of the active molecules are developed, the farming community will benefit the most due to the low toxicity and marked efficacy of neem insecticides.     

Hazardous waste management in educational and research centers: a case study

The hazardous waste management (HWM) practice at Tehran University of Medical Sciences Central Campus, Iran, was investigated in this study. Four schools were selected and the required information such as type and amount of wastes, temporary storage methods, waste discharge frequency, and final waste disposal methods using sampling, questionnaires, interviews with laboratory staff, and reference to available documents were gathered. The quantity of hazardous waste generation per year excluding the uncontrolled wastewater was found to be 2.072 tons per year. The obtained results show that wastes having features of being infectious, toxic, ignitable, carcinogenic, corrosive, and reactive were present at 32%, 28%, 16%, 14%, 8%, and 2%, respectively. In the central campus, hazardous solid wastes managed with household solid wastes and hazardous liquid waste were discharged into the sinks without any kind of control; improper HWM practices are evident from the point of waste production to final disposal.