Ciências Biológicas e da saúde

The evaluation of the growth patterns and reproductive strategies of fish species are vitally important for the understanding of their biology and the management of stocks. The present study focused on the Amazonian electric eel (Electrophorus electricus), which is capable of producing an electrical discharge of up to 800 V. Specimens were collected on a monthly schedule from a floodplain in the eastern Amazon basin. The gonads of these specimens were examined, and the sex ratio, growth parameters, population structure, body size at first gonadal maturation, and the gonadosomatic index were determined. A balanced sex ratio was found. Males were larger than females, and both sexes presented isometric growth, which is unusual in species with an elongated anatomy. This isometry may be related to the reduction of the coelomic cavity, and its position near the head. The spawning period coincided with the start of the rainy season, and continued until high water, with the variation in gonadal development following the fluctuations in precipitation and river water levels. The asymptotic body length in both sexes was relatively large, and was inversely related to the growth coefficient (k), with a slower growth rate being recorded in the males. Mortality rates were relatively low in comparison with most species of tropical fish. The larger size of the male may be related to their role in parental care, and sexual selection on the part of the females. These findings may be important for the management of wild stocks, as well as captive rearing.

1. Major hydroelectric dams are proliferating in tropical regions such as Amazonia, where extensive new hydropower developments are planned despite potentially severe ecological and social impacts. The status of freshwater biota in the vicinity of existing dams could be valuable to predict the effects of such developments, but detailed ecological monitoring before and after dam construction is frequently lacking. 2. In the absence of these data, we used a space-for-time replacement to compare a key component of the aquatic biota at upstream and downstream sites, with the latter more closely resembling river channel conditions prior to the dam. We assessed the fish assemblages upstream and downstream of the Coaracy Nunes Dam in Amap a, Brazil, the first ecological study at this site since this dam was constructed 42 years earlier. We used gillnets during eight bimonthly field campaigns, covering both wet and dry seasons, and sampled the ichthyofauna (1819 individuals, 81 species) at four sites: Downstream Channel, Reservoir, Upstream Lake and Upstream Channel. 3. We found clear negative impacts on the abundance, biomass, species richness, alpha diversity and species dominance upstream of the dam. The physical subdivision of the river channel and the upstream channel conversion from lentic to lotic habitats were strongly associated with differences in the composition and structure of fish communities. Notable changes include an increased contribution of small-bodied fish in the reservoir and an absence of long-distance migrants upstream of the dam. 4. Downstream channel habitats, in particular, retained their fish diversity with high conservation value typical of eastern Amazonia, yet these areas now face the threat of new hydropower development farther downstream. The long-term impacts on aquatic biodiversity highlighted in this study are especially relevant in the face of burgeoning new hydroelectricity development plans for rivers across lowland Amazonia.

SUMMARY 1. Major hydroelectric dams are proliferating in tropical regions such as Amazonia, where extensive new hydropower developments are planned despite potentially severe ecological and social impacts. The status of freshwater biota in the vicinity of existing dams could be valuable to predict the effects of such developments, but detailed ecological monitoring before and after dam construction is frequently lacking. 2. In the absence of these data, we used a space-for-time replacement to compare a key component of the aquatic biota at upstream and downstream sites, with the latter more closely resembling river channel conditions prior to the dam. We assessed the fish assemblages upstream and downstream of the Coaracy Nunes Dam in Amap a, Brazil, the first ecological study at this site since this dam was constructed 42 years earlier. We used gillnets during eight bimonthly field campaigns, covering both wet and dry seasons, and sampled the ichthyofauna (1819 individuals, 81 species) at four sites: Downstream Channel, Reservoir, Upstream Lake and Upstream Channel. 3. We found clear negative impacts on the abundance, biomass, species richness, alpha diversity and species dominance upstream of the dam. The physical subdivision of the river channel and the upstream channel conversion from lentic to lotic habitats were strongly associated with differences in the composition and structure of fish communities. Notable changes include an increased contribution of small-bodied fish in the reservoir and an absence of long-distance migrants upstream of the dam. 4. Downstream channel habitats, in particular, retained their fish diversity with high conservation value typical of eastern Amazonia, yet these areas now face the threat of new hydropower development farther downstream. The long-term impacts on aquatic biodiversity highlighted in this study are especially relevant in the face of burgeoning new hydroelectricity development plans for rivers across lowland Amazonia.

1. Major hydroelectric dams are proliferating in tropical regions such as Amazonia, where extensive new hydropower developments are planned despite potentially severe ecological and social impacts. The status of freshwater biota in the vicinity of existing dams could be valuable to predict the effects of such developments, but detailed ecological monitoring before and after dam construction is frequently lacking. 2. In the absence of these data, we used a space-for-time replacement to compare a key component of the aquatic biota at upstream and downstream sites, with the latter more closely resembling river channel conditions prior to the dam. We assessed the fish assemblages upstream and downstream of the Coaracy Nunes Dam in Amap a, Brazil, the first ecological study at this site since this dam was constructed 42 years earlier. We used gillnets during eight bimonthly field campaigns, covering both wet and dry seasons, and sampled the ichthyofauna (1819 individuals, 81 species) at four sites: Downstream Channel, Reservoir, Upstream Lake and Upstream Channel. 3. We found clear negative impacts on the abundance, biomass, species richness, alpha diversity and species dominance upstream of the dam. The physical subdivision of the river channel and the upstream channel conversion from lentic to lotic habitats were strongly associated with differences in the composition and structure of fish communities. Notable changes include an increased contribution of small-bodied fish in the reservoir and an absence of long-distance migrants upstream of the dam. 4. Downstream channel habitats, in particular, retained their fish diversity with high conservation value typical of eastern Amazonia, yet these areas now face the threat of new hydropower development farther downstream. The long-term impacts on aquatic biodiversity highlighted in this study are especially relevant in the face of burgeoning new hydroelectricity development plans for rivers across lowland Amazonia.

The crude hydroalcoholic extract of Alpinia speciosa (JC Wendl.) K. Schum was administered for six weeks to twenty-two patients, thirteen of which had mild hypertension (stage 1 hypertension) and nine of which had moderate hypertension (stage 2 hypertension).
Patients were submitted to the following laboratory tests prior to and after treatment: complete blood count, glucose, serum urea and creatinine, total cholesterol, triglycerides, uric acid, transaminases, bilirubins, alkaline phosphatase, serum sodium and potassium, urinalysis and EKG. Thirteen patients were treated with only one capsule of 250 mg/day containing the crude hydroalcoholic extract of A. speciosa. Eight patients were treated with two capsules, and only one was treated with the maximum dose under study, which was six capsules of crude hydroalcoholic A. speciosa extract. The biochemical and hematological tests performed showed no statistically
significant differences between pretreatment and post-treatment, and the dosing regimen used was effective in significantly reducing blood pressure in stages 1 and 2. Furthermore, there was no report or identification of toxic side-effects, thereby demonstrating good tolerance.

Middle-aged individuals with favorable levels of all major cardiovascular risk factors (CVRFs) have much lower age-specific risks for incident cardiovascular disease (CVD). However, the relationship of the absence of CVRFs with subclinical CVD and inflammation is not well described. We classified 440 asymptomatic Brazilian men (aged 46AE7 years) based on the number of CVRFs (smoking, systolic blood pressure !130 mm Hg, low-density lipoprotein cholesterol !130 mg ⁄ dL, high-density lipoprotein cholesterol <40 mg ⁄ dL, triglycerides !150 mg ⁄ dL, fasting glucose !100 mg ⁄ dL, and waist circumference >102 cm). Only 7% had no CVRFs, whereas 1, 2, 3, and !4 CVRFs were observed in 18%, 24%, 21%, and 29%, respectively. In age-adjusted analysis, each lower CVRF profile was associated with lower odds of prevalent coronary artery calcium (odds ratio, 0.75; P¼.002) and elevated white blood cell count (odds ratio, 0.70; P<.001). Our study supports the notion that a favorable CVD profile is associated with less underlying atherosclerosis and inflammation and further highlights the importance of primary prevention of CVRFs.

The Amazon region displays a rich and diverse biota encompassing more than 50,000 botanical species . A few medicinal plants commonly utilized by local people has been studied concerning its pharmacological properties. New antiretroviral drugs are on demand, mainly in developing countries and particularly in Brazil, which exhibit an exuberant biota, it is mandatory to rationally explore its immense and diverse floristic potential for medicinal purposes [2].

a b s t r a c t E. oleracea is a tropical plant from the Amazon region, with its fruit used for food, and traditionally, as an antioxidant, anti-inflammatory, hypocholesterolemic, for atherosclerotic disease, and has anticancer properties. The oil of the fruit has antidiarrheic, anti-inflammatory and antinociceptive activities, but without genotoxicity evaluation. Therefore, the aim of this study was to evaluate the genotoxic potential of E. oleracea fruit oil (EOO), in rat cells. Male Wistar rats were treated with EOO by gavage at doses of 30, 100 and 300 mg/kg, for 14 days, within a 24 h interval. The DNA damage in the leukocytes, liver, bone marrow and testicular cells, was assessed by the comet assay, and the clastogenic/aneugenic effects in the bone marrow cells, by the micronucleus test. Our phytochemicals characterization of the EOO showed the presence of vanillic, palmitic, g -linolenic, linoleic, oleic, cinnamic, caffeic, protocatechuic, ferulic, syringic acids, and flavonoids quercetin and kaempferol rutinoside as the main constituents. Both cytogenetic tests performed showed that EOO presented no significant genotoxic effects in the analyzed cells, at the three tested doses. These results indicate that, under our experimental conditions, E. oleracea fruit oil did not reveal genetic toxicity in rat cells.

Aerobic and facultative bacteria belonging to the Enterobacteriaceae, Pseudomonadaceae, Bacillaceae, Corynebacteriaceae and Streptococcaceae families have been isolated from corroded metallic structures of a hydroelectric power unit in the Amazon region of Brazil. In addition to anamorphic dematiaceous and moniliaceous fungi, members of the archeobacteria kingdom were also detected in the same samples. Scanning electron micrographs of metal bars cultivated with consortia of the isolated microorganisms depicted suggestiveimagesofbiofilmformationandcorrodedmetallicstructuresquestioningthepossibleroleofthese microorganismsinthe corrosion activity. We also found Amazonian medicinal plants exhibiting inhibitory activity against some of the isolated microorganisms. Our new findings need additional studies to confirm the participation of some isolated microorganisms in the process of metallic degradationdespiteourmainquestionifarethereparticularmicroorganismsinvolvedinthecorrosionprocess?orif physicochemical conditions would favor the development of a particular microbiota and consequently the corrosion process would result from its metabolism?Thereforewehypothesizethatanymicroorganismcouldbepotentiallyinvolvedinthegenesisofcorrosionprocess.Thisis thefirstreportintheliteraturedealingwithmicrobiologicallyinducedcorrosionintheAmazonregionwhichisespecially characterized by its high humidity and elevated temperature all year round.