Drought promotes increases in total mercury and methylmercury concentrations in fish from the lower Paraíba do Sul river, southeastern Brazil.

Bioaccumulation of mercury and methylmercury in fish represents a serious risk to human beings. Extreme climate events like droughts may increase the trophic transfer of contaminants and net methylation of mercury. The present study assessed the influence of the 2014 drought on total mercury and methylmercury levels in fish from the lower Paraiba do Sul river basin. Contaminant levels were compared for Pimelodus fur, Pachyurus adspersus, Pimelodella lateristriga, Oligosarcus hepsetus, and Crenicichla lacustris captured in five sites in 2013 (N = 212) and 2014 (N = 231). The results indicate that levels of contaminants were higher during the drought in most species. Rainfall was weakly and negatively correlated with total mercury levels in most of the species. The weak relationship between these two variables was due to the indirect influence of rainfall on mercury bioaccumulation. In summary, drought increased the levels of two contaminants in fish.

Risk of ingesting As, Cd, and Pb in animal products in north Rio de Janeiro state, Brazil.

This study evaluated the levels of As, Cd, and Pb in muscle and liver the cattle and chicken. The risk was estimated for the adult population of a midsized city in southeast Brazil, concerning the tolerable ingestion and cancer risk. Samples of muscle and liver (cattle and chicken) were collected (n = 250). Samples of mineral supplements for cattle (n = 4) and chicken feed samples (n = 4) were evaluated as one of many potential source of contamination. Muscle, liver, mineral supplement, and feed samples were dissolved in acid medium and analyzed by ICP-OES. Daily muscle and liver intake was estimated using a questionnaire (N = 427). Daily intake of trace elements by the population based on the consumption of cattle muscle, cattle liver, chicken muscle, and chicken liver was low, corresponding to 2.76%, 0.33%, 2.12%, and 0.22% of the Tolerable Intake defined by the WHO for As; 0.54%, 0.29% 0.55%, 0.01%, for Cd; and 0.80%, 0.07%, 0.62%, 0.02%, for Pb. The mean of total ingestion of As, Cd and Pb was 5.43%, 1.18% and 1.51%, respectively of Tolerable Intake defined by WHO. Cancer risk was lower than 5 × 10-5 year-1. The results indicate that the muscle and liver consumption is a source of As, Cd, and Pb. Consumers that ingest cattle and chicken muscle need attention in terms the risk of cancer related to intake of As and Cd. Feed and mineral supplementation remain as one of many sources of exposure of As, Cd, and Pb.

Spatial-temporal dynamics and sources of total Hg in a hydroelectric reservoir in the Western Amazon, Brazil.

Damming rivers to construct hydroelectric reservoirs results in a series of impacts on the biogeochemical Hg cycle. For example, modifying the hydrodynamics of a natural watercourse can result in the suspension and transport of Hg deposits in the water column, which represents an exposure risk for biota. The objective of this study was to evaluate the influences of seasonality on the dispersion of total Hg in the Hydroelectric Power Plant (HPP)-Samuel Reservoir (Porto Velho/Brazil). Sampling campaigns were performed during the three following hydrological periods characteristic of the region: low (Oct/2011), ebbing (May/2012), and high (Feb/2013) water. Sediment profiles, suspended particulate matter (SPM), and aquatic macrophytes (Eicchornia crassipes and Oryza spp.) were collected, and their Hg concentrations and isotopic and elemental C and N signatures were determined. The drainage basin significantly influenced the SPM compositions during all the periods, with a small autochthonous influence from the reservoir during the low water. The highest SPM Hg concentrations inside the reservoir were observed during the high water period, suggesting that the hydrodynamics of this environment favor the suspension of fine SPM, which has a higher Hg adsorption capacity. The Hg concentrations in the sediment profiles were ten times lower than those in the SPM, indicating that large particles with low Hg concentrations were deposited to form the bottom sediment. Hg concentrations were higher in aquatic macrophyte roots than in their leaves and appeared to contribute to the formation of SPM during the low water period. In this environment, Hg transport mainly occurs in SPM from the Jamari River drainage basin, which is the primary source of Hg in this environment.

Paraneoplastic limbic encephalitis--neurologic paraneoplastic syndrome associated with ovarian malignancy--the importance of clinical recognition.

Paraneoplastic limbic encephalitis (PLE) is a rare disorder and it is also under-reported due to the difficulty in establishing the diagnosis. The delay in treatment could potentially lead to devastating neurological outcomes. The authors report a 32-year-old Caucasian, nullipara woman, who presented with a subacute dementia associated to generalized tonic-clonic seizure with rapid progression to coma. The diagnosis of immature ovarian teratoma surgical Stage FIGO IA R0 with PLE was confirmed. The patient began earlier oral corticosterois and human intravenous immunoglobulin. She was discharged one month after surgery with no neurologic deficit and remains three years later in oncological remission. A diagnosis of PLE should be considered in the differential diagnosis of unexplained dementias. Early diagnosis, treatment of the underlying malignancy, and prompt intervention with immunotherapy in this patient at the onset of presentation facilitated regression of the neurological syndrome and explains the favorable neurological outcome.

Long-term survival in basal cell carcinoma metastatic to bone: a case report.

A total of 97 cases of metastatic basal cell carcinoma have been reported in the literature, 22 of which were metastatic to bone. To date there has been no survival following bone metastasis. A case report of significant long-term survival--over three times the expected--is presented. The treatment described is perhaps a guideline for management of basal cell carcinoma metastatic to bone, though it is presumed the basic biological nature of the tumor determines length and quality of survival.