Protective Effect of Grape and Apple Juices against Cadmium Intoxication in the Kidney of Rats.

BACKGROUND: The objective of this study was to evaluate protective effect of grape and apple juices against toxicity induced by cadmium in the kidney of rats. METHODS: A total of 20 male-Wistar rats were distributed into four groups (n=5): Control group: animals received an intraperitoneal (i.p.) injection of 0.9% saline solution and after 15 days, 1 mL of water was administered for 15 days, via gavage; Cadmium group: animals received an intraperitoneal injection of cadmium chloride (1.2 mg/kg) and after 15 days, 1 mL of water was administered for 15 days via gavage; Cadmium+Grape Juice: animals received an i.p. injection of cadmium chloride (1.2 mg/kg), and after 15 days, 0.8 mL of grape juice was administered for 15 days, via gavage; Cadmium+Apple Juice: animals received i.p. injection of cadmium chloride (1.2 mg/kg) and after 15 days, 1.0 mL of apple juice was administered for 15 days, via gavage. RESULTS: Histopathological analysis revealed severe tubular lesion and necrosis in the group exposed to cadmium, while animals exposed to grape or apple juices showed a significant reduction of tissue injury. 8-OHdG immunoexpression, DNA damage, cytochrome C and catalase gene expressions and Toll like signaling pathway (TLR2, and pIKKα/ß) decreased in animals treated with grape juice when compared to cadmium group. CONCLUSION: Taken together, we conclude that grape and apple juices had a protective effect by means of antioxidant, antigenotoxic actions and for promoting tissue regeneration in the kidney of rats following cadmium intoxication.

Toxic leukoencephalopathies, including drug, medication, environmental, and radiation-induced encephalopathic syndromes.

Toxic leukoencephalopathies can be secondary to the exposure to a wide variety of exogenous agents, including cranial irradiation, chemotherapy, antiepileptic agents, drugs of abuse, and environmental toxins. There is no typical clinical picture, and patients can present with a wide array of signs and symptoms. Involvement of white matter is a key finding in this scenario, although in some circumstances other high metabolic areas of the central nervous system can also be affected. Magnetic resonance (MR) imaging usually discloses bilateral and symmetric white matter areas of hyperintense signal on T2-weighted and fluid-attenuated inversion recovery images, and signs of restricted diffusion are associated in the acute stage. In most cases, the changes are reversible, especially with prompt recognition of the disease and discontinuation of the noxious agent. Either the MR or clinical features may be similar to several nontoxic entities, such as demyelinating diseases, leukodystrophies, hepatic encephalopathy, vascular disease, hypoxic-ischemic states, and others. A high index of suspicion should be maintained whenever a patient presents recent onset of neurologic deficit, searching the risk of exposure to a neurotoxic agent. Getting to know the most frequent MR appearances and mechanisms of action of causative agents may help to make an early diagnosis and begin therapy, improving outcome. In this review, some of the most important causes of leukoencephalopathies are presented; as well as other 2 related conditions: strokelike migraine attacks after radiation therapy syndrome and reversible splenial lesions.

DNA damage and decreased DNA repair in peripheral blood mononuclear cells in individuals exposed to arsenic and lead in a mining site.

The aim of this study was to evaluate DNA damage and the capacity for DNA repair in children exposed to arsenic and lead. During 2006, we studied a total of 85 healthy children (aged 4-11 years) who were residents of Villa de la Paz (community A), Matehuala (community B), and Soledad de Graciano Sanchez (community C) in San Luis Potosi, Mexico. The quantification of arsenic in urine (AsU) and lead in blood (PbB) was performed by atomic absorption spectrophotometry. The alkaline comet assay was used to evaluate DNA damage and DNA repair. The highest levels of AsU and PbB in children were found in community A (44.5 µg/g creatinine for arsenic and 11.4 µg/dL for lead), followed by community B (16.8 µg/g creatinine for arsenic and 7.3 µg/dL for lead) and finally by children living in community C (12.8 µg/g creatinine for arsenic and 5.3 µg/dL for lead). When DNA damage was assessed, children living in community A had the highest DNA damage. Analysis of these same cells 1 h after a challenge with H(2)O(2) 10 µM showed a dramatic increase in DNA damage in the cells of children living in community B and community C, but not in the cells of children living in community A. Moreover, significantly higher levels of DNA damage were observed 3 h after the challenge ended (repair period) in cells from individuals living in community A. Our results show that children exposed to metals might be more susceptible to DNA alterations.

[Community clinical toxicology]. / Toxicología clínica comunitaria.

In some Latin American countries acute intoxication is professionally managed by specialized physicians qualified in the area. Something similar occurs with work-related chronic intoxication in the formal sector. However, a different reality prevails for the assessment of chronic intoxication of environmental origin, since it is by definition more difficult to diagnose. For treatment of acute intoxication, Toxicological Information and Care Centers have been set up, though similar bodies have not been created for chronic environmental intoxication. Therefore, in this study a model of chronic intoxication care is proposed, using multidisciplinary teams adopting a new approach, namely Community Clinical Toxicology, the goal of which would be the simultaneous care of acute intoxication which is generally treated in hospital, and environmental intoxication that is normal dealt with at community level. The ultimate goal is to take advantage of the expertise that exists in the Region in terms of Clinical Toxicology to organize community work.

Toxicología clínica comunitaria / Community Clinical Toxicology

En algunos países de América Latina las intoxicaciones agudas se manejan de manera profesional por médicos especialistas en la mate-ria. Algo similar ocurre con las intoxicaciones crónicas de origen laboral en el sector formal. No obstante, una realidad diferente ocurre en cuanto a la evaluación de las intoxicaciones crónicas de origen ambiental, dado que éstas por su naturaleza, son más difíciles de diagnosticar. Para el tratamiento de las intoxicaciones agudas se han organizado Centros de Información y Atención Toxicológica, pero para las intoxicaciones crónicas ambientales no se ha generado organismos semejantes. Por consiguiente, en este trabajo sugerimos un modelo de atención de la intoxicaciones crónicas a través de grupos multidisciplinarios bajo el esquema de una nueva disciplina: la Toxicología Clínica Comunitaria, cuyo objetivo sería la atención simultánea de las intoxicaciones agudas que generalmente se atienden en un ámbito hospitalario y de las intoxicaciones ambientales que por lo normal se presentan a nivel comunitario. El objetivo final es aprovechar la experiencia que existe en la Región en cuanto a Toxicología Clínica para organizar el trabajo comunitario.

In some Latin American countries acute intoxication is professionally managed by specialized physicians qualified in the area. Something similar occurs with work-related chronic intoxication in the formal sector. However, a different reality prevails for the assessment of chronic intoxication of environmental origin, since it is by definition more difficult to diagnose. For treatment of acute intoxication, Toxicological Information and Care Centers have been set up, though similar bodies have not been created for chronic environmental intoxication. Therefore, in this study a model of chronic intoxication care is proposed, using multidisciplinary teams adopting a new approach, namely Community Clinical Toxicology, the goal of which would be the simultaneous care of acute intoxication which is generally treated in hospital, and environmental intoxication that is normal dealt with at community level. The ultimate goal is to take advantage of the expertise that exists in the Region in terms of Clinical Toxicology to organize community work.

Factors associated with self-reported symptoms of acute pesticide poisoning among farmers in northwestern Jamaica.

Pesticide poisoning is a major public health concern in developing countries. The authors conducted a population survey among farmers in 3 parishes of northwestern Jamaica to determine the occurrence of acute pesticide poisoning and to identify factors associated with pesticide poisoning. Approximately 16% of 359 farmers who participated in the study reported 1 or more incidents of acute pesticide poisoning within the last 2 years. Only 25% of the farmers reported ever receiving training in pesticide handling or safety. The majority (68%) of farmers who reported pesticide poisoning never sought medical attention for poisoning. The factors found to be associated with pesticide poisoning in this study indicate that implementation of specific intervention strategies and education of farmers is needed in order to improve safe handling, use, and disposal of pesticides and reduce incidents of acute pesticide poisoning.

Bisphenol a exposure in Mexico City and risk of prematurity: a pilot nested case control study.

BACKGROUND: Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely. METHODS: A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry. RESULTS: BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 µg/L to 6.7 µg/L; uncorrected geometric mean was 1.52 µg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05). CONCLUSIONS: This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.

Immune systems, geographic information systems (GIS), environment and health impacts.

Exposure to dioxins, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) has been related to alterations in cellular and humoral immune responses in both adaptive and innate immune systems of most animal species. These compounds share a common signaling mechanism to exert their effects on cells of the immune system, which includes the aryl-hydrocarbon receptor (AhR) and the AhR nuclear translocator (ARN). Recently, the interference of AhR-ARNT with the nuclear factor (NF)-kappaB signaling pathway has been proposed as a critical event in the adverse effects on the immune system. Studies on the effects of these AhR-ARNT-related toxicants on the immune system of higher and lower phylum animals and knowledge of intracellular mechanisms of toxicity may contribute to development of biomarkers of ecotoxicant exposure and effects. Biomarkers of this kind allow sampling over extended geographic areas, in several sentinel species, including wildlife animals, and facilitate the building of risk models and risk maps of environmentally induced diseases. On the basis of location, biomarker sampled data obtained through evaluation of ecotoxicant exposure and effects on the immune system in sentinel species can be further integrated and analyzed together with other sources of environmental geographic information, or human population health data, by means of geographic information systems (GIS). The spatial analysis capability of GIS can help to evaluate the complex relationships of overlaid information and to identify areas with high risk indices or "hot spots." This integrative approach can be useful in studies contributing to support environmental and health-related policies and regulations.

Seasonal pesticide use in a rural community on the US/Mexico border.

An environmental measurement and correlation study of infant and toddler exposure to pesticides was carried out in a colonia south of the city of Laredo, Texas. As part of the study, homes were visited during the late spring or summer, and during the winter of 2000-2001. At each visit, families reported on their use of pesticides in and around the home and floor wipe samples were collected and analyzed for 14 organophosphate and triazine pesticides. Selection of homes was based on the presence of infants and toddlers. A total of 27 homes participated in both seasonal visits. The interval between visits was 6 +/- 1.4 months. Univariate and multivariate nonparametric analyses were carried out using SPSS statistical software. Pesticide use within the home was more often reported than outside use and showed seasonal variation in use patterns. Indoor use was primarily associated with ants and cockroaches, and secondarily with rodents. The primary room treated was the kitchen, and the primary structures treated were the floors, lower walls, and dish cupboards. Seasonal variations were not found in the use of pesticides used outside the home and outdoor use was primarily associated with ant control. Based on parent reports, most pesticides used in the homes were pyrethroids. Several of the pesticides measured in floor wipe samples, Azinphos methyl, Fonofos, and Simazine, also showed seasonal variations. However, these pesticides are used in agriculture and were not associated with reported house and yard use patterns.

Dichlorodiphenyldichloroethane burden and breast cancer risk: a meta-analysis of the epidemiologic evidence.

The relationship of dichlorodiphenyltrichloroethane (DDT) exposure and breast cancer risk has received increasing attention since the beginning of the 1990s. Contradicting published results regarding the relationship between body burden levels of p,p'-dichlorodiphenyldichloroethane (p,p'-DDE)--the main DDT metabolite--and breast cancer, we argue that such differences stem from methodologic differences among those studies. We performed a meta-analysis of 22 articles using DerSimonian and Laird's method for random effects models. The Q-statistic was used to identify heterogeneity in the outcome variable across studies. The gradient of p,p'-DDE exposure in epidemiologic studies was homogenized to serum lipid bases (nanograms per gram). The potential for publication bias was examined by means of the Begg's test. We discuss methodologic features of the studies in an attempt to reconcile the findings. The summary odds ratio (OR) for selected studies was 0.97 (95% confidence interval, 0.87-1.09) and the gradient of exposure ranged from 84.37 to 12,948 ng/g. No overall heterogeneity in the OR was observed (chi-squared = 27.93; df = 23; p = 0.218). Neither the study design nor the lack of breast-feeding control or the type of biologic specimen used to measure p,p'-DDE levels were the causes of heterogeneity throughout the studies. Evidence for publication bias was not found (p = 0.253). Overall, these results should be regarded as a strong evidence to discard the putative relationship between p,p'-DDE and breast cancer risk. Nevertheless, the exposure to DDT during critical periods of human development--from conception to adolescence--and individual variations in metabolizing enzymes of DDT or its derivatives are still important areas to be researched in regard to breast cancer development in adulthood.

Environmental factors associated with a spectrum of neurodevelopmental deficits.

A number of environmental agents have been shown to demonstrate neurotoxic effects either in human or laboratory animal studies. Critical windows of vulnerability to the effects of these agents occur both pre- and postnatally. The nervous system is relatively unique in that different parts are responsible for different functional domains, and these develop at different times (e.g., motor control, sensory, intelligence and attention). In addition, the many cell types in the brain have different windows of vulnerability with varying sensitivities to environmental agents. This review focuses on two environmental agents, lead and methylmercury, to illustrate the neurobehavioral and cognitive effects that can result from early life exposures. Special attention is paid to distinguishing between the effects detected following episodes of poisoning and those detected following lower dose exposures. Perinatal and childhood exposure to high doses of lead results in encephalopathy and convulsions. Lower-dose lead exposures have been associated with impairment in intellectual function and attention. At high levels of prenatal exposure, methylmercury produces mental retardation, cerebral palsy and visual and auditory deficits in children of exposed mothers. At lower levels of methylmercury exposure, the effects in children have been more subtle. Other environmental neurotoxicants that have been shown to produce developmental neurotoxicity include polychlorinated biphenyls (PCBs), dioxins, pesticides, ionizing radiation, environmental tobacco smoke, and maternal use of alcohol, tobacco, marijuana and cocaine. Exposure to environmental agents with neurotoxic effects can result in a spectrum of adverse outcomes from severe mental retardation and disability to more subtle changes in function depending on the timing and dose of the chemical agent.

Comparison of four human studies of perinatal exposure to methylmercury for use in risk assessment.

Newer data from human epidemiologic studies of methylmercury (MeHg) poisoning in which perinatal exposure occurred are available from four distinct populations. The results of an Iraqi grain-consuming population are compared to results from studies performed in fish-consuming groups in the Faroe Islands, the Seychelles Islands and in Peruvian fishing villages. A comparison of the results indicate that the Iraqi population does not represent a sensitive subpopulation within a perinatal group, but rather the relative lower threshold identified from this study was the results of confounders. Use of this benchmark dose for regulatory purposes may place a severe limitation upon fish consumption in the United States that is not fully supported by the scientific data.

Evaluating a fluorosis hazard after a volcanic eruption.

The August, 1991 eruption of Mt. Hudson (Chile) deposited ash across southern Argentina and contributed to the deaths of thousands of grazing sheep. Early ash analysis revealed high levels of fluoride, a potential ash constituent toxic to humans and animals. In order to evaluate fluorosis as the cause of sheep deaths and to examine the possibility that similar ash and airborne toxins could also have an effect on the human population, we conducted an investigation that included health provider interviews, hospital record review, physical examination of sheep, determination of sheep urine fluoride levels, and complete constituent analysis of ash samples collected at proscribed distances from the volcano. Ash deposited farthest from the volcano had highest fluoride levels; all fluoride measurements were normal after rainfall. There were no signs or symptoms of fluorosis observed in sheep or humans. Sheep deaths resulted from physical, rather than chemical properties of the ash.