Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil

Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil, was studied from September 1993 to October 1994 to assess the current levels of resource exploitation. Hunting effort, harvesting yields and species composition of the hunt were recorded daily in five villages varying in number of people, location and age of the settlement. The Waimiri Atroari harvested a total of 3004 individuals of 41 species in one year. Lowland tapir (Tapirus terrestris), white-lipped peccary (Tayassu pecari), collared peccary (T. tajacu) and spider monkey (Ateles paniscus) represented 87% of the total yearly game weight. Sex ratios of spider monkeys killed were heavily biased towards females indicating a stronger hunting pressure on those individuals. Harvesting yields was proportional to hunting efforts indicating no evident game depletion in the study period. However, capture per unit of effort was significantly different among villages. Differences in total game mass harvested may be explained by local resource depletion associated with age and size of the settlement. However, this relationship is confounded by the capacity of some villages to exploit distant hunting sites. Data obtained in one village showed that harvest rates were higher in hunting sites located far from settlement indicating game depletion in hunting sites surrounding the village.     

Uric acid activates NRLP3 inflammasome in an in-vivo model of epithelial to mesenchymal transition in the kidney

Uric acid (UA) has been associated with renal fibrosis and progression of chronic kidney disease. However, the underlying mechanisms of this process have still not been identified. Here, we studied the role of the innate imunity receptor NLRP3/ASC in UA induced epithelial-mesenchymal transition (EMT) in kidney. Wistar rats were fed with oxonic acid 2% and UA 2% (OXA?+?U), OXA?+?U plus allopurinol (ALL) or regular chow (C) for 7 weeks. We analyzed the presence of EMT markers, the expression of NLRP3, ASC, Caspase-1 and Smad 2/3 molecules and the mitochondrial morphological and functional characteristics. High UA induced renal fibrosis, mild chronic inflammation, as well as morphological and biochemical evidence of EMT. High UA also increased the expression of NLRP3/ASC with activation of both inflammasome related caspase-1 and inflammasome unrelated Smad 2/3 pathways. Ultrastructural co-localization of NLRP3 and Smad 2/3 indicated physical interaction between the two molecules. No morphological or functional changes were found between mitochondria exposed to high UA. In conclusion, kidney epithelial NLRP3/ASC expression was increased in high UA state in rats and both inflammasome related caspase-1 and non-inflammasome related P-Smad 2/3 pathways were associated with the observed EMT, inflammation and fibrosis induced by UA in the kidney.     

Low-level laser therapy attenuates the acute inflammatory response induced by muscle traumatic injury

The purpose of this work was to investigate the effect of early and long-term low-level laser therapy (LLLT) on oxidative stress and inflammatory biomarkers after acute-traumatic muscle injury in Wistar rats. Animals were randomly divided into the following four groups: control group (CG), muscle injury group (IG), CG?+?LLLT, and IG?+?LLLT: laser treatment with doses of 3 and 5 J/cm². Muscle traumatic injury was induced by a single-impact blunt trauma in the rat gastrocnemius. Irradiation for 3 or 5 J/cm² was initiated 2, 12, and 24?h after muscle trauma induction, and the treatment was continued for five consecutive days. All the oxidant markers investigated. namely thiobarbituric acid-reactive substance, carbonyl, superoxide dismutase, glutathione peroxidase, and catalase, were increased as soon as 2?h after muscle injury and remained increased up to 24?h. These alterations were prevented by LLLT at a 3 J/cm² dose given 2?h after the trauma. Similarly, LLLT prevented the trauma-induced proinflammatory state characterized by IL-6 and IL-10. In parallel, trauma-induced reduction in BDNF and VEGF, vascular remodeling and fiber-proliferating markers, was prevented by laser irradiation. In order to test whether the preventive effect of LLLT was also reflected in muscle functionality, we tested the locomotor activity, by measuring distance traveled and the number of rearings in the open field test. LLLT was effective in recovering the normal locomotion, indicating that the irradiation induced biostimulatory effects that accelerated or resolved the acute inflammatory response as well as the oxidant state elicited by the muscle trauma.     

Mitochondrial Respiration Chain Enzymatic Activities in the Human Brain: Methodological Implications for Tissue Sampling and Storage

Neurochemical Research - Mitochondrial respiratory chain complexes enzymatic (MRCCE) activities were successfully evaluated in frozen brain samples. Epilepsy surgery offers an ethical opportunity...     

1,25(OH)2 vitamin D3 signalling on immature rat Sertoli cells: gamma-glutamyl transpeptidase and glucose metabolism

1α,25-Dihydroxyvitamin D₃ (1,25-D₃) is critical for the maintenance of normal male reproduction since reduced fertility is observed in vitamin D-deficient rats. Gamma-glutamyl transpeptidase (GGT) is a membrane-bound enzyme that is localized on Sertoli cells and catalyses the transfer of the gamma-glutamyl residues to an amino acid or peptide acceptor. Sertoli cells are also responsible for providing nutrients, as lactate, to the development of germ cells. The aim of this study was to investigate the effect and the mechanism of action of 1,25-D₃ on GGT on Sertoli cell functions from 30-day-old immature rat testis. Results demonstrated that 1,25-D₃ stimulates GGT activity at Sertoli cells plasma membrane through a PKA-dependent mechanism of action, which was not dependent of active de novo protein synthesis. The hormone increases glucose uptake, as well as lactate production and release by Sertoli cells without altering the reactive oxygen species (ROS) generation. In addition, 1,25-D₃ did not change reduced glutathione (GSH) amount or oxygen consumption, and diminished Sertoli cell death. These findings demonstrate that 1,25-D₃ stimulatory effect on GGT activity, glucose uptake, LDH activity and lactate production seem to be an important contribution of Sertoli cells for germ cells nutrition and for a full and active ongoing spermatogenesis.     

In vivo manganese exposure modulates Erk, Akt and Darpp-32 in the striatum of developing rats, and impairs their motor function

Manganese (Mn) is an essential metal for development and metabolism. However, exposures to high Mn levels may be toxic, especially to the central nervous system (CNS). Neurotoxicity is commonly due to occupational or environmental exposures leading to Mn accumulation in the basal ganglia and a Parkinsonian-like disorder. Younger individuals are more susceptible to Mn toxicity. Moreover, early exposure may represent a risk factor for the development of neurodegenerative diseases later in life. The present study was undertaken to investigate the developmental neurotoxicity in an in vivo model of immature rats exposed to Mn (5, 10 and 20 mg/kg; i.p.) from postnatal day 8 (PN8) to PN12. Neurochemical analysis was carried out on PN14. We focused on striatal alterations in intracellular signaling pathways, oxidative stress and cell death. Moreover, motor alterations as a result of early Mn exposure (PN8-12) were evaluated later in life at 3-, 4- and 5-weeks-of-age. Mn altered in a dose-dependent manner the activity of key cell signaling elements. Specifically, Mn increased the phosphorylation of DARPP-32-Thr-34, ERK1/2 and AKT. Additionally, Mn increased reactive oxygen species (ROS) production and caspase activity, and altered mitochondrial respiratory chain complexes I and II activities. Mn (10 and 20 mg/kg) also impaired motor coordination in the 3^rd, 4^th and 5^th week of life. Trolox™, an antioxidant, reversed several of the Mn altered parameters, including the increased ROS production and ERK1/2 phosphorylation. However, Trolox™ failed to reverse the Mn (20 mg/kg)-induced increase in AKT phosphorylation and motor deficits. Additionally, Mn (20 mg/kg) decreased the distance, speed and grooming frequency in an open field test; Trolox™ blocked only the decrease of grooming frequency. Taken together, these results establish that short-term exposure to Mn during a specific developmental window (PN8-12) induces metabolic and neurochemical alterations in the striatum that may modulate later-life behavioral changes. Furthermore, some of the molecular and behavioral events, which are perturbed by early Mn exposure are not directly related to the production of oxidative stress.