Thermal impact of a nuclear power plant in a coastal area in Southeastern Brazil: effects of heating and physical structure on benthic cover and fish communities

The influence of a nuclear power plant’s cooling water and physical structure on benthic cover and fish communities were assessed in a coastal area in Southeastern Brazil. We hypothesised that thermal discharges decrease benthic cover and consequently, change the associated rocky reef fish assemblage structure and that physical structure is directly associated with fish richness and diversity. Twelve sites at different distances (close, near and far) from thermal discharge and types of physical structure (low and high) were sampled by visual census. The average surface temperature at the most impacted sites (close) ranged from 30.5 to 31°C, while at far sites it ranged from 25.5 to 28.5°C. Although thermal influences have decreased benthic cover, and consequently, decreased fish richness and diversity, we found that in near and far sites that had complex habitat structures (physical and benthic cover) fish communities were unaffected. The greatest abundances of Eucinostomus argenteus, Mugil curema and Sphoeroides greeleyi were associated with the highest temperatures at the most impacted sites. In contrast, Abudefduf saxatilis, Chaetodon striatus, Stegastes fuscus, Diplodus argenteus and Malacoctenus delalandii were more abundant at high structured sites far from thermal discharges. Our data support the hypothesis that thermal discharge decreases benthic cover, fish richness and diversity but physical structure, when coupled with high diversity and abundant benthic cover, minimised thermal effects on fish communities.     

Fit-climbing test: a field test for indoor rock climbing

The aim of this study was to develop an indoor rock-climbing test on an artificial wall (Fit-climbing test). Thirteen climbers (elite group [EG] = 6; recreational group [RG] = 7) performed the following tests: (a) familiarization in the Fit-climbing test, (b) the Fit-climbing test, and (c) a retest to evaluate the Fit-climbing test's reliability. Gas exchange, blood lactate concentration, handgrip strength, and heart rate were measured during the test. Oxygen uptake during the Fit-climbing test was not different between groups (EG = 8.4 ± 1.1 L; RG = 7.9 ± 1.5 L, p > 0.05). The EG performance (120 ± 7 movements) was statistically higher than the RG climbers' performance (78 ± 13 movements) during the Fit-climbing test. Consequently, the oxygen cost per movement during the Fit-climbing test of the EG was significantly lower than that of the RG (p < 0.05). Handgrip strength was higher in the EG when compared with that in the RG in both pre-Fit- and post-Fit-climbing test (p < 0.05). There were no significant differences in any other variables analyzed during the Fit-climbing test (p > 0.05). Furthermore, the performance in the Fit-climbing test presented high reliability (intraclass correlation coefficient = 0.97). Therefore, the performance during the Fit-climbing test may be an alternative to evaluate rock climbers because of its specificity and relation to oxygen cost per movement during climbing.     

Effects of Euterpe oleracea Mart. (A?Aí) extract in acute lung inflammation induced by cigarette smoke in the mouse

Short term inhalation of cigarette smoke (CS) induces significant lung inflammation due to an imbalance of oxidant/antioxidant mechanisms. A?ai fruit (Euterpe oleracea) has significant antioxidant and anti-inflammatory actions. The present study aimed to determine whether oral administration of an a?ai stone extract (ASE) could reduce lung inflammation induced by CS. Thirty C57BL/6 mice were assigned to three groups (n=10 each): the Control+A group was exposed to ambient air and treated orally with ASE 300 mg/kg/day; the CS group was exposed to smoke from 6 cigarettes per day for 5 days; and the CS+A group was exposed to smoke from 6 cigarettes per day for 5 days and treated orally with ASE (300 mg/kg/day). On day 6, all mice were sacrificed. After bronchoalveolar lavage, the lungs were removed for histological and biochemical analyses. The CS group exhibited increases in alveolar macrophage (AMs) and neutrophil numbers (PMNs), myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase activities (GPx), TNF-α expression, and nitrites levels in lung tissue when compared with the control ones (p<0.001 for all parameters). The AMs, PMNs, MPO, SOD, CAT, GPx and nitrite were significantly reduced by oral administration of ASE when compared with CS group (p<0.001 for all parameters, with exception of AMs p<0.01). The present results suggested that systemic administration of an ASE extract could reduce the inflammatory and oxidant actions of CS. Thus, the results of this study in mice should stimulate future studies on ASE as a potential agent to protect against CS-induced inflammation in humans.     

Boron uptake in normal melanocytes and melanoma cells and boron biodistribution study in mice bearing B16F10 melanoma for boron neutron capture therapy

Information on (10)B distribution in normal tissues is crucial to any further development of boron neutron capture therapy (BNCT). The goal of this study was to investigate the in vitro and in vivo boron biodistribution in B16F10 murine melanoma and normal tissues as a model for human melanoma treatment by a simple and rapid colorimetric method, which was validated by HR-ICP-MS. The B16F10 melanoma cell line showed higher melanin content than human melanocytes, demonstrating a greater potential for boronophenylalanine uptake. The melanocytes showed a moderate viability decrease in the first few minutes after BNCT application, stabilizing after 75 min, whereas the B16F10 melanoma showed the greatest intracellular boron concentration at 150 min after application, indicating a different boron uptake of melanoma cells compared to normal melanocytes. Moreover, at this time, the increase in boron uptake in melanoma cells was approximately 1.6 times higher than that in normal melanocytes. The (10)B concentration in the blood of mice bearing B16F10 melanoma increased until 90 min after BNCT application and then decreased after 120 min, and remained low until the 240th minute. On the other hand, the (10)B concentration in tumors was increased from 90 min and maximal at 150 min after application, thus confirming the in vitro results. Therefore, the present in vitro and in vivo study of (10)B uptake in normal and tumor cells revealed important data that could enable BNCT to be possibly used as a treatment for melanoma, a chemoresistant cancer associated with high mortality.     

Structure of Dioclea virgata lectin: Relations between carbohydrate binding site and nitric oxide production

The lectin of Dioclea virgata (DvirL), both native and complexed with X-man, was submitted to X-ray diffraction analysis and the crystal structure was compared to that of other Diocleinae lectins in order to better understand differences in biological properties, especially with regard to the ability of lectins to induce nitric oxide (NO) production. An association was observed between the volume of the carbohydrate recognition domain (CRD), the ability to induce NO production and the relative positions of Tyr12, Arg228 and Leu99. Thus, differences in biological activity induced by Diocleinae lectins are related to the configuration of amino acid residues in the carbohydrate binding site and to the structural conformation of subsequent regions capable of influencing site-ligand interactions. In conclusion, the ability of Diocleinae lectins to induce NO production depends on CRD configuration.     

Two Fe-superoxide dismutase families respond differently to stress and senescence in legumes

Three main families of SODs in plants may be distinguished according to the metal in the active center: CuZnSODs, MnSOD, and FeSOD. CuZnSODs have two sub-families localized either in plant cell cytosol or in plastids, the MnSOD family is essentially restricted to mitochondria, and the FeSOD enzyme family has been typically localized into the plastid. Here, we describe, based on a phylogenetic tree and experimental data, the existence of two FeSOD sub-families: a plastidial localized sub-family that is universal to plants, and a cytosolic localized FeSOD sub-family observed in determinate-forming nodule legumes. Anti-cytosolic FeSOD (cyt_FeSOD) antibodies were employed, together with a novel antibody raised against plastidial FeSOD (p_FeSOD). Stress conditions, such as nitrate excess or drought, markedly increased cyt_FeSOD contents in soybean tissues. Also, cyt_FeSOD content and activity increased with age in both soybean and cowpea plants, while the cyt_CuZnSOD isozyme was predominant during early stages. p_FeSOD in leaves decreased with most of the stresses applied, but this isozyme markedly increased with abscisic acid in roots. The great differences observed for p_FeSOD and cyt_FeSOD contents in response to stress and aging in plant tissues reveal distinct functionality and confirm the existence of two immunologically differentiated FeSOD sub-families. The in-gel FeSOD activity patterns showed a good correlation to cyt_FeSOD contents but not to those of p_FeSOD. This indicates that cyt_FeSOD is the main active FeSOD in soybean and cowpea tissues. The diversity of functions associated with the complexity of FeSOD isoenzymes depending of the location is discussed.     

Single- or Pair-Housed: Which Is Better for Captive Southern Tamanduas?

The captive environment can limit some important behavioral options for nonhuman animals, which often results in decreased welfare. The companion of a conspecific can be a source of complexity in captivity, but this aspect has received little attention for solitary species. This study investigated the effects of two different housing conditions on the behavior of a solitary species, the Southern tamandua (Tamandua tetradactyla). Six individuals housed singly and four housed in pairs in two Brazilian zoological institutions were observed for 10 days from 09:00h to 17:00h during the rainy season. Each individual was observed for 26:40 hours. Compared with singly housed tamanduas, paired animals were less inactive (single = 74.62 ± 5.2%, paired = 28.51 ± 0.04% of the records), foraged and explored more (single = 11.07 ± 3.0%, paired 31.48 ± 0.01% of the records), and exhibited a diversity of behaviors 102.56% greater than single tamanduas. These results suggest that interactions with conspecifics in captivity, even for solitary animals, can promote the performance of desirable behaviors, which in several species has been correlated with improved welfare.     

Dimethylthiourea protects against mitochondrial oxidative damage induced by cisplatin in liver of rats

Cisplatin is one of the most effective chemotherapeutic agents. However, at higher doses liver injury may occur. The purpose of this study was to explore whether the hydroxyl radical scavenger dimethylthiourea (DMTU) protects against cisplatin-induced oxidative damage in vivo and to define the mitochondrial pathways involved in cytoprotection. Adult male Wistar rats (200–220 g) were divided into four groups of eight animals each. The control group was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml/100 g body weight). The DMTU group was given only DMTU (500 mg/kg body weight, i.p), followed by 125 mg/kg body weight, i.p. (twice a day) until sacrifice. The cisplatin group was given a single injection of cisplatin (10 mg/kg body weight, i.p.). The DMTU + cisplatin group was given DMTU (500 mg/kg body weight, i.p.), just before the cisplatin injection (10 mg/kg body weight, i.p.), followed by injections of DMTU (125 mg/kg body weight, i.p.) twice a day until sacrifice (72 h after the treatment). DMTU did not present any direct effect on mitochondria and substantially inhibited cisplatin-induced mitochondrial damage in liver, therefore preventing elevation of AST and ALT serum levels. DMTU protected against (a) decreased hepatic ATP levels; (b) lipid peroxidation; (c) cardiolipin oxidation; (d) sulfhydryl protein oxidation; (e) mitochondrial membrane rigidification; (f) GSH oxidation; (g) NADPH oxidation; (h) apoptosis. Results suggest that antioxidants, particularly hydroxyl radical scavengers, protect liver mitochondria against cisplatin-induced oxidative damage. Several mitochondrial changes were delineated and proposed as interesting targets for cytoprotective strategy.