Influence of training in the dark or light phase on physiologic and metabolic parameters of Wistar rats submitted to aerobic exercise

Light and dark phase training may influences rodents’ physiologic parameters because these animals have nocturnal habits. Thus, we verify the effects of the training in different photoperiods on metabolism and corporal composition of rats. Eighteen rats were divided into three groups – G1: non-trained; G2: trained in the light phase; G3: trained in the dark phase. Rats were allowed to swim for 60 min, five times per week during six weeks. Trained animals presented a smaller weight gain and fat percentage in carcass. Rats of G3 increased gastrocnemius relative weight. The adipocyte diameter of G3 rats was smaller than the other groups. The levels of the total cholesterol, low-density proteins, and triacylglycerols were decreased in animals of G2 while the glycemia was increased. Training in light phase provided more alterations in the blood biochemical profile while the training in the dark increased the gastrocnemius weight and decreased the diameter of the adipocyte.     

Experimental evidence of habitat selection and territoriality in the Amazonian whip spider Heterophrynus longicornis (Arachnida, Amblypygi)

Animals that select and defend suitable habitats against conspecifics may be favored by maximizing prey encounter rate, gaining protection, or securing matings. However, the identification of habitat selection and territoriality may be hindered in observational studies in sedentary species with low-density populations, such as the whip spider Heterophrynus longicornis. To circumvent such difficulties, we adopted an experimental field approach to evaluate if H. longicornis selects and defends habitat in Central Amazon. To evaluate whether individuals perform habitat selection, we monitored the permanence of 29 experimentally released individuals in buttressed trees with a wide variation in diameter at breast height (DBH), with and without burrows at their bases. To evaluate whether individuals are territorial, we experimentally removed 21 individuals from their previously occupied trees and monitored the recolonization of these trees. If H. longicornis were territorial, we predicted that the recolonizers would be smaller than the removed individuals. We found 12 individuals in the trees where they were released on subsequent days, none of them in trees without burrows. The individual permanence was related to the presence of burrows, and not to DBH. There was recolonization by smaller males and females on ten trees from which the amblypygids were removed. In combination, the permanence of individuals in trees with burrows, the rapid recolonization of experimentally vacated trees by smaller individuals, and the preponderance of one individual per tree, suggest that both male and female H. longicornis perform habitat selection and also that after selecting a site, they defend it against conspecifics.     

Moonlight and blood-feeding behaviour of Lutzomyia intermedia and Lutzomyia whitmani (Diptera:Psychodidae:Phlebotominae), vectors of American cutaneous leishmaniasis in Brazil

Lutzomyia intermedia (Lutz & Neiva, 1912) and L. whitmani (Antunes & Coutinho, 1939) (Diptera: Psychodidae: Phlebotominae), two important vectors of American cutaneous leishmaniasis in Brazil, occur in sympatry in the locality of Posse county, Petropolis municipality, state of Rio de Janeiro, Brazil. We investigated the influence of the lunar cycle on the frequency of specimens of the two species caught while attempting to bite the collectors and in CDC light traps. Analysis of the numbers of sand flies captured in different lunar phases for two consecutive years in the peridomestic site and forest shows that there is a significant positive correlation between moonlight intensity and the numbers of L. intermedia and L. whitmani females collected while blood-feeding, whereas the opposite was observed for the CDC traps.     

Invasive pulmonary aspergillosis due to a mixed infection caused by Aspergillus flavus and Aspergillus fumigatus

Invasive pulmonary aspergillosis is typically caused by a single Aspergillus species, most frequently Aspergillus fumigatus. Here we report that a lung transplant recipient developed invasive aspergillosis due to a mixed infection caused by Aspergillus flavus and A. fumigatus. The implications for this unusual finding are discussed.     

The interaction of Bacteroides fragilis with components of the human fibrinolytic system

Bacteroides fragilis is a minor component of the intestinal microbiota and the most frequently isolated from intra-abdominal infections and bacteremia. Previously, our group has shown that molecules involved in laminin-1 (LMN-1) recognition were present in outer membrane protein extracts of B. fragilis MC2 strain. One of these proteins was identified and showed 98% similarity to a putative B. fragilis plasminogen-binding protein precursor, deposited in the public database. Thus, the objective of this work was to overexpress and further characterize this novel adhesin. The ability of B. fragilis MC2 strain and purified protein to convert plasminogen into plasmin was tested. Our results showed that B. fragilis strain MC2 strain adhered to both LMN-1 and plasminogen and this adhesion was inhibited by either LMN-1 or plasminogen. Regarding the plasminogen activation activity, both the whole bacterial cell and the purified protein converted plasminogen into plasmin similar to streptokinase used as a positive control. Bacterial receptors that recognize plasminogen bind to it and enhance its activation, transforming a nonproteolytic bacterium into a proteolytic one. We present in vitro evidence for a pathogenic function of the plasminogen receptor in promoting adherence to laminin and also the formation of plasmin by B. fragilis .     

Cilostazol and pentoxifylline decrease angiogenesis,inflammation, and fibrosis in sponge-induced intraperitoneal adhesion in mice

AimsAdhesion formation following abdominal intervention is an abnormal peritoneal healing process. Our aim was to investigate the effects of controlling adhesion development by inhibiting its key components (angiogenesis, inflammation and fibrosis) using phosphodiesterase (PDE) inhibitors.Main methodsTwo PDE inhibitors including cilostazol a PDE3 inhibitor (40 and 400 mg/kg), and pentoxifylline (PTX), a PDE 1–5 inhibitor (50 and 500 mg/kg) were used for a period of 7 days to inhibit angiogenesis, inflammation, and fibrosis in a murine model of sponge-induced peritoneal adhesion. Angiogenesis was assessed by hemoglobin content, vascular endothelial growth factor (VEGF) levels, and morphometric analysis. Accumulation of neutrophils and macrophages was determined by measuring myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activities, respectively. Levels of TNF-α were also determined. Fibrosis was assessed by determining the amount of collagen in the implant; TGF-β1 levels in the implant were also measured.Key findingsOur results show that the treatments attenuated the main components of the adhesion tissue by reducing the amount of fibrovascular tissue that infiltrated the sponge matrix (wet weight). Hemoglobin content and VEGF levels were also decreased by approximately 40%. Neutrophil accumulation was unaffected by the compounds. However, NAG activity was reduced by pentoxifylline, but not by cilostazol. These compounds also decreased the levels of the pro-inflammatory and pro-fibrogenic cytokines TNF-α and TGF-β1, respectively, and collagen synthesis.SignificanceOur results suggest that cilostazol and PTX decreased the development of peritoneal adhesions in the model, which might be associated with cyclic nucleotide modulation. Therapies to intervene in these pathways may be beneficial for the prevention of these lesions.     

Are fentanyl and remifentanil safe opioids for rat brain mitochondrial bioenergetics?

Fentanyl and remifentanil are potent opioid widely used in routine anesthesia procedures. This study evaluates and compares the effects of fentanyl/remifentanil in isolated brain mitochondria bioenergetic status. Fentanyl and remifentanil in clinical concentrations does not interfere with rat brain isolated mitochondria. Do not withstand, fentanyl concentrations >4 μg/mL, induces an impairment of the respiratory chain characterized by a decrease in respiratory control ratio, state 3 and uncoupled respiration. Additionally, membrane potential collapses and ADP/O were reduced. Remifentanil follows the same profile but with effects at higher concentrations (>10 μg/mL). High concentrations of fentanyl and remifentanil interfere with mitochondrial electron chain (complexes III, IV) and on mitochondrial phosphorylation unit (complex V). Mitochondrial permeability transition pore was not induced by both fentanyl and remifentanil in tested concentrations. These data provide the first indication that fentanyl and remifentanil (μg/mL range) alters mitochondrial metabolism. Fentanyl showed a stronger inhibitory effect on mitochondrial bioenergetics.     

Guarana (Paullinia cupana var. sorbilis), an anciently consumed stimulant from the Amazon rain forest: the seeded-fruit transcriptome

Guarana (Paullinia cupana var. sorbilis) is a plant native to the central Amazon basin. Roasted seed extracts have been used as medicinal beverages since pre-Colombian times, due to their reputation as stimulants, aphrodisiacs, tonics, as well as protectors of the gastrointestinal tract. Guarana plants are commercially cultivated exclusively in Brazil to supply the national carbonated soft-drink industry and natural product stores around the world. In this report, we describe and discuss the annotation of 15,387 ESTs from guarana seeded-fruits, highlighting sequences from the flavonoid and purine alkaloid pathways, and those related to biotic stress avoidance. This is the largest set of sequences registered for the Sapindaceae family.