A fototerapia com diodo emissor de luz (LEDT) aplicada pré-exercício inibe a peroxidação lipídica em atletas após exercício de alta intensidade: um estudo preliminar

Estresse oxidativo é o termo geralmente utilizado para descrever os danos causados pelo desequilíbrio entre pró-oxidantes e antioxidantes no organismo. O aumento no consumo de O2 induzido pelo exercício físico está associado ao aumento das espécies reativas de oxigênio (EROs) sendo estas indutoras do estresse oxidativo. Embora as evidências indiquem um provável efeito inibitório da fototerapia com diodos emissores de luz (LEDT) sobre a produção das EROs, não existem estudos observando tal efeito em atletas. Este estudo preliminar destina-se a verificar os efeitos da aplicação de LEDT previamente ao exercício de alta intensidade sobre a peroxidação lipídica, mensurada através dos níveis sanguíneos de substâncias reativas ao ácido tiobarbitúrico (TBARS). Todos os seis atletas de voleibol do sexo masculino foram submetidos às duas situações: aplicação de LEDT efetiva e aplicação de LEDT placebo. O desempenho no protocolo de exercício adotado não revelou diferença (p > 0,05) entre as duas situações nas variáveis potência pico, potência média e índice de fadiga. Os resultados relacionados com a peroxidação lipídica foram: na situação LEDT efetiva, não foi possível observar diferença estatisticamente significante (p > 0,05) entre os níveis pré e pós-exercício (6,98 ± 0,81 e 7,02 ± 0,47nmol/mL); na situação LEDT (LBP) placebo, houve diferença estatisticamente significante (p = 0,05) entre os valores pré e pós-exercício (7,09 ± 1,28 e 8,43 ± 0,71nmol/mL). Tais resultados demonstram que a aplicação efetiva de LEDT parece ser eficaz no controle da peroxidação lipídica em atletas submetidos a exercício intenso

Induction of a gloverin-like antimicrobial polypeptide in the sugarcane borer Diatraea saccharalis challenged by septic injury

Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) is an important pest for Brazilian sugarcane. In the present study, we detected two distinct spots in hemolymph from septic injured larvae (HDs1 and HDs2), which are separated by 2DE gel electrophoresis. Both spots were subjected to in-gel tryptic digestion and MALDI-TOF/TOF analysis, which revealed the sequence VFGTLGSDDSGLFGK present in both HDs1 and HDs2. This sequence had homology and 80% identity with specific Lepidoptera antimicrobial peptides called gloverins. Analyses using the ImageMaster 2D software showed pI 8.94 of the HDs1 spot, which is similar to that described to Hyalophora gloveri gloverin (pI 8.5). Moreover, the 14-kDa molecular mass of the spot HDs1 is compatible to that of gloverins isolated from the hemolymph of Trichoplusia ni, Helicoverpa armigera and H. gloveri. Antimicrobial assays with partially purified fractions containing the HDs1 and HDs2 polypeptides demonstrated activity against Escherichia coli. This is the first report of antimicrobial polypeptides in D. saccharalis, and the identification of these peptides may help in the generation of new strategies to control this pest.

Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedelianaO. Berg, Myrtaceae

The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.

Antidepressant-like effects of an apolar extract and chow enriched with Nepeta cataria (catnip) in mice

Nepeta cataria (catnip) is a plant used in pet toys and to treat human diseases. Catnip has also been used in the treatment of some depressive disorders. In this paper, we studied the antidepressant, anxiogenic, and motor activity effects of acute and repeated feeding of chow enriched with 10% N. cataria leaves and the acute and repeated administration of apolar and polar extracts of N. cataria leaves in male mice. The results showed that repeated feeding and acute and repeated administration with the apolar extract reduced immobility in the behavioral despair test but did not alter elevated plus maze and open-field parameters. Acute feeding and the acute and repeated administration of the polar extracts of N. cataria leaves did not alter the behavior of mice. These data suggest that N. cataria has antidepressant properties. Moreover, this antidepressant activity was present in the apolar extract.

Toll-like receptor 4 (TLR4) expression in human and murine pancreatic beta-cells affects cell viability and insulin homeostasis

Background: Toll-like receptor 4 (TLR4) is widely recognized as an essential element in the triggering of innate immunity, binding pathogen-associated molecules such as Lipopolysaccharide (LPS), and in initiating a cascade of pro-inflammatory events. Evidence for TLR4 expression in non-immune cells, including pancreatic beta-cells, has been shown, but, the functional role of TLR4 in the physiology of human pancreatic beta-cells is still to be clearly established. We investigated whether TLR4 is present in beta-cells purified from freshly isolated human islets and confirmed the results using MIN6 mouse insulinoma cells, by analyzing the effects of TLR4 expression on cell viability and insulin homeostasis. Results: CD11b positive macrophages were practically absent from isolated human islets obtained from nondiabetic brain-dead donors, and TLR4 mRNA and cell surface expression were restricted to beta-cells. A significant loss of cell viability was observed in these beta-cells indicating a possible relationship with TLR4 expression. Monitoring gene expression in beta-cells exposed for 48h to the prototypical TLR4 ligand LPS showed a concentration-dependent increase in TLR4 and CD14 transcripts and decreased insulin content and secretion. TLR4-positive MIN6 cells were also LPS-responsive, increasing TLR4 and CD14 mRNA levels and decreasing cell viability and insulin content. Conclusions: Taken together, our data indicate a novel function for TLR4 as a molecule capable of altering homeostasis of pancreatic beta-cells.

Environmental isolation of black yeast-like fungi involved in human infection

The present study focuses on potential agents of chromoblastomycosis and other endemic diseases in the state of Parana, Southern Brazil. Using a highly selective protocol for chaetothyrialean black yeasts and relatives, environmental samples from the living area of symptomatic patients were analysed. Additional strains were isolated from creosote-treated wood and hydrocarbon-polluted environments, as such polluted sites have been supposed to enhance black yeast prevalence. Isolates showed morphologies compatible with the traditional etiological agents of chromoblastomycosis, e.g. Fonsecaea pedrosoi and Phialophora verrucosa, and of agents of subcutaneous or systemic infections like Cladophialophora bantiana and Exophiala jeanselmei. Some agents of mild disease were indeed encountered. However, molecular analysis proved that most environmental strains differed from known etiologic agents of pronounced disease syndromes: they belonged to the same order, but mostly were undescribed species. Agents of chromoblastomycosis and systemic disease thus far are prevalent on the human host. The hydrocarbon-polluted environments yielded yet another spectrum of chaetothyrialean fungi. These observations are of great relevance because they allow us to distinguish between categories of opportunists, indicating possible differences in pathogenicity and virulence.

Origins of the Xylella fastidiosa Prophage-Like Regions and Their Impact in Genome Differentiation

Xylella fastidiosa is a Gram negative plant pathogen causing many economically important diseases, and analyses of completely sequenced X. fastidiosa genome strains allowed the identification of many prophage-like elements and possibly phage remnants, accounting for up to 15% of the genome composition. To better evaluate the recent evolution of the X. fastidiosa chromosome backbone among distinct pathovars, the number and location of prophage-like regions on two finished genomes (9a5c and Temecula1), and in two candidate molecules (Ann1 and Dixon) were assessed. Based on comparative best bidirectional hit analyses, the majority (51%) of the predicted genes in the X. fastidiosa prophage-like regions are related to structural phage genes belonging to the Siphoviridae family. Electron micrograph reveals the existence of putative viral particles with similar morphology to lambda phages in the bacterial cell in planta. Moreover, analysis of microarray data indicates that 9a5c strain cultivated under stress conditions presents enhanced expression of phage anti-repressor genes, suggesting switches from lysogenic to lytic cycle of phages under stress-induced situations. Furthermore, virulence-associated proteins and toxins are found within these prophage-like elements, thus suggesting an important role in host adaptation. Finally, clustering analyses of phage integrase genes based on multiple alignment patterns reveal they group in five lineages, all possessing a tyrosine recombinase catalytic domain, and phylogenetically close to other integrases found in phages that are genetic mosaics and able to perform generalized and specialized transduction. Integration sites and tRNA association is also evidenced. In summary, we present comparative and experimental evidence supporting the association and contribution of phage activity on the differentiation of Xylella genomes.

An AC-5 cathepsin B-like protease purified from Haemonchus contortus excretory secretory products shows protective antigen potential for lambs

The immunogenic properties of cysteine proteases obtained from excretory/secretory products (ES) of Haemonchus contortus were investigated with a fraction purified with a recombinant H. contortus cystatin affinity column. The enrichment of H. contortus ES for cysteine protease was confirmed with substrate SDS-PAGE gels since the cystatin-binding fraction activity was three times higher than total ES, despite representing only 3% of total ES. This activity was inhibited by a specific cysteine protease inhibitor (E64) and by recombinant cystatin. The one-dimensional profile of the cystatin-binding fraction displayed a single band with a molecular mass of 43 kDa. Mass spectrometry showed this to be AC-5, a cathepsin B-like cysteine protease which had not been identified in ES products of H. contortus before. The cystatin binding fraction was tested as an immunogen in lambs which were vaccinated three times (week 0, 2.5 and 5), challenged with 10 000 L3 H. contortus (week 6) before necropsy and compared to unvaccinated challenge controls and another group given total ES (n = 10 per group). The group vaccinated with cystatin-binding proteins showed 36% and 32% mean worm burden and eggs per gram of faeces (EPG) reductions, respectively, compared to the controls but total ES was almost without effect. After challenge the cystatin-binding proteins induced significantly higher local and systemic ES specific IgA and IgG responses.

Toxic Epidermal Necrolysis-like Cutaneous Lupus Erythematosus: A Series of Three Patients

Toxic epidermal necrolysis-like lesions have been described in the setting of lupus erythematosus, and have been considered as a specific hyperacute variant of cutaneous lupus erythematosus, with features different from classical drug-related toxic epidermal necrolysis. We report here a series of three patients with lupus erythematosus who presented with severe worsening of their cutaneous disease in a toxic epidermal necrolysis-like fashion. We compared these cases with cases reported previously. Based on this discussion, we speculate that some of these patients may have classical drug-related toxic epidermal necrolysis rather than lupus erythematosus-related toxic epidermal necrolysis.

Endometrial claudin-4 and leukemia inhibitory factor are associated with assisted reproduction outcome

Background: Claudin-4 (CLDN4) is one of several proteins that act as molecular mediators of embryo implantation. Recently, we examined immunolabeling of leukemia inhibitory factor (LIF) in the endometrial tissue of 52 IVF patients, and found that LIF staining intensity was strongly correlated with successful pregnancy initiation. In the same set of patients, we have now examined endometrial CLDN4 expression, to see how expression intensity may vary with LIF. We examined CLDN4 in the luteal phase of the menstrual cycle, immediately preceding IVF treatment. Our aim was to compare expression of LIF and CLDN4 in the luteal phase, and document these patterns as putative biomarkers for pregnancy. Methods: Endometrial tissue was collected from women undergoing IVF. Endometrial biopsies were obtained during the luteal phase preceding IVF, and were then used for tissue microarray (TMA) immunolabeling of CLDN4. Previously published LIF expression data were then combined with CLDN4 expression data, to determine CLDN4/LIF expression patterns. Associations between successful pregnancy after IVF and combined CLDN4/LIF expression patterns were evaluated. Results: Four patterns of immunolabeling were observed in the endometrial samples: 16% showed weak CLDN4 and strong LIF (CLDN4(-)/LIF(+)); 20% showed strong CLDN4 and strong LIF (LIF(+)/CLDN4(+)); 28% showed strong CLDN4 and weak LIF (CLDN4(+)/LIF(-)); and 36% showed weak CLDN4 and weak LIF (CLDN4(-)/LIF(-)). Successful implantation after IVF was associated with CLDN4(-)/LIF(+)(p = 0.003). Patients showing this endometrial CLDN4(-)/LIF(+) immunolabeling were also 6 times more likely to achieve pregnancy than patients with endometrial CLDN4(+)/LIF(-) immunolabeling (p = 0.007). Conclusion: The combined immunolabeling expression of CLDN4(-)/LIF(+) in endometrial tissue is a potential biomarker for predicting successful pregnancy in IVF candidates.

Maternal immunization with ovalbumin prevents neonatal allergy development and up-regulates inhibitory receptor Fc gamma RIIB expression on B cells

Background: Preconception allergen immunization prevents neonatal allergen sensitization in mice by a complex interaction between regulatory cells/factors and antibodies. The present study assessed the influence of maternal immunization with ovalbumin (OVA) on the immune response of 3 day-old and 3 week-old offspring immunized or non-immunized with OVA and evaluated the effect of IgG treatment during fetal development or neonatal period. Results: Maternal immunization with OVA showed increased levels of Fc gamma RIIb expression in splenic B cells of neonates, which were maintained for up to 3 weeks and not affected by additional postnatal OVA immunization. Maternal immunization also exerted a down-modulatory effect on both IL-4 and IFN-gamma-secreting T cells and IL-4 and IL-12-secreting B cells. Furthermore, immunized neonates from immunized mothers showed a marked inhibition of antigen-specifc IgE Ab production and lowered Th2/Th1 cytokine levels, whereas displaying enhanced Fc gamma RIIb expression on B cells. These offspring also showed reduced antigen-specific proliferative response and lowered B cell responsiveness. Moreover, in vitro evaluation revealed an impairment of B cell activation upon engagement of B cell antigen receptor by IgG from OVA-immunized mice. Finally, in vivo IgG transference during pregnancy or breastfeeding revealed that maternal Ab transference was able to increase regulatory cytokines, such as IL-10, in the prenatal stage; yet only the postnatal treatment prevented neonatal sensitization. None of the IgG treatments induced immunological changes in the offspring, as it was observed for those from OVA-immunized mothers. Conclusion: Maternal immunization upregulates the inhibitory Fc gamma RIIb expression on offspring B cells, avoiding skewed Th2 response and development of allergy. These findings contribute to the advancement of prophylactic strategies to prevent allergic diseases in early life.

Acute reversible inactivation of the bed nucleus of stria terminalis induces antidepressant-like effect in the rat forced swimming test

Background: The bed nucleus of stria terminalis (BNST) is a limbic forebrain structure involved in hypothalamo-pituitary-adrenal axis regulation and stress adaptation. Inappropriate adaptation to stress is thought to compromise the organism's coping mechanisms, which have been implicated in the neurobiology of depression. However, the studies aimed at investigating BNST involvement in depression pathophysiology have yielded contradictory results. Therefore, the objective of the present study was to investigate the effects of temporary acute inactivation of synaptic transmission in the BNST by local microinjection of cobalt chloride (CoCl(2)) in rats subjected to the forced swimming test (FST). Methods: Rats implanted with cannulae aimed at the BNST were submitted to 15 min of forced swimming (pretest). Twenty- four hours later immobility time was registered in a new 5 min forced swimming session (test). Independent groups of rats received bilateral microinjections of CoCl(2) (1 mM/100 nL) before or immediately after pretest or before the test session. Additional groups received the same treatment and were submitted to the open field test to control for unspecific effects on locomotor behavior. Results: CoCl(2) injection into the BNST before either the pretest or test sessions reduced immobility in the FST, suggesting an antidepressant-like effect. No significant effect of CoCl(2) was observed when it was injected into the BNST immediately after pretest. In addition, no effect of BNST inactivation was observed in the open field test. Conclusion: These results suggest that acute reversible inactivation of synaptic transmission in the BNST facilitates adaptation to stress and induces antidepressant-like effects.

Characterization of Novel OmpA-Like Protein of Leptospira interrogans That Binds Extracellular Matrix Molecules and Plasminogen

Leptospira interrogans is the etiological agent of leptospirosis, a zoonotic disease of human and veterinary concern. The identification of novel proteins that mediate host-pathogen interactions is important for understanding the bacterial pathogenesis as well as to identify protective antigens that would help fight the disease. We describe in this work the cloning, expression, purification and characterization of three predicted leptospiral membrane proteins, LIC10258, LIC12880 (Lp30) and LIC12238. We have employed Escherichia coli BL21 (SI) strain as a host expression system. Recently, we have identified LIC12238 as a plasminogen (PLG)-binding receptor. We show now that Lp30 and rLIC10258 are also PLG-receptors of Leptospira, both exhibiting dose-dependent and saturating binding (K(D), 68.8 +/- 25.2 nM and 167.39 +/- 60.1 nM, for rLIC10258 and rLIC12880, respectively). In addition, LIC10258, which is a novel OmpA-like protein, binds laminin and plasma fibronectin ECM molecules and hence, it was named Lsa66 (Leptospiral surface adhesin of 66 kDa). Binding of Lsa66 to ECM components was determined to be specific, dose-dependent and saturable, with a KD of 55.4 +/- 15.9 nM to laminin and of 290.8 +/- 11.8 nM to plasma fibronectin. Binding of the recombinant proteins to PLG or ECM components was assessed by using antibodies against each of the recombinant proteins obtained in mice and confirmed by monoclonal anti-polyhistidine antibodies. Lsa66 caused partial inhibition on leptospiral adherence to immobilized ECM and PLG. Moreover, this adhesin and rLIC12238 are recognized by antibodies in serum samples of confirmed leptospirosis cases. Thus, Lsa66 is a novel OmpA-like protein with dual activity that may promote the attachment of Leptospira to host tissues and may contribute to the leptospiral invasion. To our knowledge, this is the first leptospiral protein with ECM and PLG binding properties reported to date.

Serotonin receptors are involved in the spinal mediation of descending facilitation of surgical incision-induced increase of Fos-like immunoreactivity in rats

Background: Descending pronociceptive pathways may be implicated in states of persistent pain. Paw skin incision is a well-established postoperative pain model that causes behavioral nociceptive responses and enhanced excitability of spinal dorsal horn neurons. The number of spinal c-Fos positive neurons of rats treated intrathecally with serotonin, noradrenaline or acetylcholine antagonists where evaluated to study the descending pathways activated by a surgical paw incision. Results: The number of c-Fos positive neurons in laminae I/II ipsilateral, lamina V bilateral to the incised paw, and in lamina X significantly increased after the incision. These changes: remained unchanged in phenoxybenzamine-treated rats; were increased in the contralateral lamina V of atropine-treated rats; were inhibited in the ipsilateral lamina I/II by 5-HT(1/2B/2C) (methysergide), 5-HT(2A) (ketanserin) or 5-HT(1/2A/2C/5/6/7) (methiothepin) receptors antagonists, in the ipsilateral lamina V by methysergide or methiothepin, in the contralateral lamina V by all the serotonergic antagonists and in the lamina X by LY 278,584, ketanserin or methiothepin. Conclusions: We conclude: (1) muscarinic cholinergic mechanisms reduce incision-induced response of spinal neurons inputs from the contralateral paw; (2) 5-HT(1/2A/2C/3) receptors-mediate mechanisms increase the activity of descending pathways that facilitates the response of spinal neurons to noxious inputs from the contralateral paw; (3) 5-HT(1/2A/2C) and 5-HT(1/2C) receptors increases the descending facilitation mechanisms induced by incision in the ipsilateral paw; (4) 5-HT(2A/3) receptors contribute to descending pronociceptive pathways conveyed by lamina X spinal neurons; (5) alpha-adrenergic receptors are unlikely to participate in the incision-induced facilitation of the spinal neurons.

Spiral-like structure at the centre of nearby clusters of galaxies

Context. X-ray data analysis have found that fairly complex structures at cluster centres are more common than expected. Many of these structures have similar morphologies, which exhibit spiral-like substructure. Aims. It is not yet well known how these structures are formed or maintained. Understanding the origin of these spiral-like features at the centre of some clusters is the major motivation behind this work. Methods. We analyse deep Chandra observations of 15 nearby galaxy clusters ( 0.01 < z < 0.06), and use X-ray temperature and substructure maps to detect small features at the cores of the clusters. Results. We detect spiral-like features at the centre of 7 clusters: A85, A426, A496, Hydra A cluster, Centaurus, Ophiuchus, and A4059. These patterns are similar to those found in numerical hydrodynamic simulations of cluster mergers with non-zero impact parameter. In some clusters of our sample, a strong radio source also occupies the inner region of the cluster, which indicates a possible connection between the two. Our investigation implies that these spiral-like structures may be caused by off-axis minor mergers. Since these features occur in regions of high density, they may confine radio emission from the central galaxy producing, in some cases, unusual radio morphology.