Peripheral antinociceptive action of mangiferin in mouse models of experimental pain: Role of endogenous opioids, KATP-channels and adenosine

AbstractThis study aimed to assess the possible systemic antinociceptive activity of mangiferin and to clarify the underlying mechanism, using the acute models of chemical (acetic acid, formalin, and capsaicin) and thermal (hot-plate and tail-flick) nociception in mice. Mangiferin at oral doses of 10 to 100mg/kg evidenced significant antinociception against chemogenic pain in the test models of acetic acid-induced visceral pain and in formalin- and capsaicin-induced neuro-inflammatory pain, in a naloxone-sensitive manner, suggesting the participation of endogenous opiates in its mechanism. In capsaicin test, the antinociceptive effect of mangiferin (30mg/kg) was not modified by respective competitive and non-competitive transient receptor potential vanilloid 1 (TRPV1) antagonists, capsazepine and ruthenium red, or by pretreatment with l-NAME, a non-selective nitric oxide synthase inhibitor, or by ODQ, an inhibitor of soluble guanylyl cyclase. However, mangiferin effect was significantly reversed by glibenclamide, a blocker of KATP channels and in animals pretreated with 8-phenyltheophylline, an adenosine receptor antagonist. Mangiferin failed to modify the thermal nociception in hot-plate and tail-flick test models, suggesting that its analgesic effect is only peripheral but not central. The orally administered mangiferin (10–100mg/kg) was well tolerated and did not impair the ambulation or the motor coordination of mice in respective open-field and rota-rod tests, indicating that the observed antinociception was unrelated to sedation or motor abnormality. The findings of this study suggest that mangiferin has a peripheral antinociceptive action through mechanisms that involve endogenous opioids, KATP-channels and adenosine receptors

Exercícios resistidos e uso de decanoato de nandrolona e a alteração do epidídimo de ratos adultos e idosos / Resistence training and the use of nandrolone decanoate change epididymis in adult and aged rats

Introdução: O sistema genital masculino é alvo de estudos por ser sensível a mudanças na concentração de androgênios, e esses são alterados em algumas situações como: exercício, uso de anabolizantes (EAAs) e o envelhecimento. Um dos órgãos androgênio-dependentes é o epidídimo. Objetivo: Verificar se o tratamento com EAAs associado ou não a exercício físico, em ratos Sprague-Dawley altera a morfologia e morfometria do Epidídimo em ratos adultos e seus efeitos crônicos em idosos. Métodos: Foram analisados epidídimos de 56 ratos Sprague-Dawley, virgens, com 13 semanas de vida ao início do experimento, separados em oito grupos com sete animais cada: GC - adultos e sedentários; GCi - idosos e sedentários; GN - adultos, sedentários, tratados com EAA; GNi - idosos, sedentários, tratados com EAA; GE - adultos tratados com exercício; GEi - idosostratados com exercício; GNE - adultos, exercício e tratamento com EAA; GNEi - idosos, exercício e tratamento com EAA. Os animais adultos foram eutanasiados com 150 dias, os idosos, 330 dias. O treinamento realizado foi através de saltos na água, com sobrecarga. A administração de EAAs ocorreu pela aplicação intramuscular de Decanoato de Nandrolona (10 mg/kg/semana). Amostras epididimárias passaram pela rotina histológica de hematoxilina e eosina para análise morfológica e morfométrica. Resultados: O GE apresentou diâmetro de ducto menor quando comparados ao controle, já o GN e GNE, tiveram diâmetro de ducto e a altura epitelial aumentados comparando-os com o controle, sendo estas alterações principalmente nos segmentos mais iniciais do epidídimo. Já os grupos idosos tenderam a retornar a normalidade, a não ser na cauda, do GNEi. Também foram encontrados indícios inflamatórios no tecido dos grupos experimentais (GN, GE, GNE e GCi) e ainda, debris de células da linhagem germinativa no interior do lúmen de GN e GNEi. Conclusão: Tanto o tratamento na fase adulta com exercício, quanto à utilização de EAAs altera parâmetros morfométricos e morfológicos do epidídimo, e  seu efeito crônico pode ser diminuído com a idade

Low-temperature applied to rice seed storage: an efficient protection method against fungal contamination

Low-temperatures have long been thought to enhance seed health during storage. Here we tested the effect of low-temperature on the mycoflora associated with rice seeds. Seeds of the IRGA 423 and 424 cultivars were stored in refrigeration (8 and -50°C) or at room temperature (25 ± 10°C). Following storage (1, 45, and 90 days) was investigated the fungi associated with the seeds. We found that, for both cultivars, low-temperature stored seeds had a lower fungal load than the seeds at room temperature. After 90 days of storage, there is a decrease in its incidence rate average of more than 85% in the lower temperature (-50°C). All mycroflora was eliminated at 90 days except for Fusarium sp. The Trichoderma sp. was detected only in IRGA 423 seeds, whereas all other fungi were detected in the treatments in both cultivars. Only Bipolaris sp. was observed in seed-to-seedlings transmission analyses, in both cultivars, at 8°C, and was not detected at -50°C. Based on our results, we recommend low-temperature storage (at -50ºC) of rice seeds

Peptide:lipid ratio and membrane surface charge determine the mechanism of action of the antimicrobial peptide BP100. Conformational and functional studies

The cecropin-melittin hybrid antimicrobial peptide BP100 (H-KKLFKKILKYL-NH2) is selective for Gram-negative bacteria, negatively charged membranes, and weakly hemolytic. We studied BP100 conformational and functional properties upon interaction with large unilamellar vesicles, LUVs, and giant unilamellar vesicles, GUVs, containing variable proportions of phosphatidylcholine (PC) and negatively charged phosphatidylglycerol (PG). CD and NMR spectra showed that upon binding to PG-containing LUVs BP100 acquires a-helical conformation, the helix spanning residues 3-11. Theoretical analyses indicated that the helix is amphipathic and surface-seeking. CD and dynamic light scattering data evinced peptide and/or vesicle aggregation, modulated by peptide: lipid ratio and PG content. BP100 decreased the absolute value of the zeta potential () of LUVs with low PG contents; for higher PG, binding was analyzed as an ion-exchange process. At high salt, BP100-induced LUVS leakage requires higher peptide concentration, indicating that both electrostatic and hydrophobic interactions contribute to peptide binding. While a gradual release took place at low peptide:lipid ratios, instantaneous loss occurred at high ratios, suggesting vesicle disruption. Optical microscopy of GUVs confirmed BP100-promoted disruption of negatively charged membranes. the mechanism of action of BP100 is determined by both peptide:lipid ratio and negatively charged lipid content While gradual release results from membrane perturbation by a small number of peptide molecules giving rise to changes in acyl chain packing, lipid clustering (leading to membrane defects), and/or membrane thinning, membrane disruption results from a sequence of events large-scale peptide and lipid clustering, giving rise to peptide-lipid patches that eventually would leave the membrane in a carpet-like mechanism. (C) 2014 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Institut Nacional de Ciencia e Tecnologia de fluidos complexos (INCTFCx)Nude de Apoio Pesquisa de Fluidos Complexos (NAPFCx)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ São Paulo, Inst Chem, Dept Biochem, BR-05513970 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04044020 São Paulo, BrazilUniv Fed Rio de Janeiro, Inst Med Biochem, Nucl Magnet Resonance Natl Ctr, Rio de Janeiro, BrazilEmbrapa Recursos Genet & Biotecnol, BR-70770917 Brasilia, DF, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04044020 São Paulo, BrazilFAPESP: 2007/50970-5FAPESP: 2013/08166-5Web of Scienc

Leptospirosis-associated Severe Pulmonary Hemorrhagic Syndrome, Salvador, Brazil

We report the emergence of leptospirosis-associated severe pulmonary hemorrhagic syndrome (SPHS) in slum communities in Salvador, Brazil. Although active surveillance did not identify SPHS before 2003, 47 cases were identified from 2003 through 2005; the case-fatality rate was 74%. By 2005, SPHS caused 55% of the deaths due to leptospirosis

Development of a Cyclic Voltammetry-Based Method for the Detection of Antigens and Antibodies as a Novel Strategy for Syphilis Diagnosis

54/2017). Publisher Copyright: © 2022 by the authors.The improvement of laboratory diagnosis is a critical step for the reduction of syphilis cases around the world. In this paper, we present the development of an impedance-based method for detecting T. pallidum antigens and antibodies as an auxiliary tool for syphilis laboratory diagnosis. We evaluate the voltammetric signal obtained after incubation in carbon or gold nanoparticle-modified carbon electrodes in the presence or absence of Poly-L-Lysine. Our results indicate that the signal obtained from the electrodes was sufficient to distinguish between infected and non-infected samples immediately (T0′) or 15 min (T15′) after incubation, indicating its potential use as a point-of-care method as a screening strategy.publishersversionpublishe

Computational methods applied to syphilis: where are we, and where are we going?

Syphilis is an infectious disease that can be diagnosed and treated cheaply. Despite being a curable condition, the syphilis rate is increasing worldwide. In this sense, computational methods can analyze data and assist managers in formulating new public policies for preventing and controlling sexually transmitted infections (STIs). Computational techniques can integrate knowledge from experiences and, through an inference mechanism, apply conditions to a database that seeks to explain data behavior. This systematic review analyzed studies that use computational methods to establish or improve syphilis-related aspects. Our review shows the usefulness of computational tools to promote the overall understanding of syphilis, a global problem, to guide public policy and practice, to target better public health interventions such as surveillance and prevention, health service delivery, and the optimal use of diagnostic tools. The review was conducted according to PRISMA 2020 Statement and used several quality criteria to include studies. The publications chosen to compose this review were gathered from Science Direct, Web of Science, Springer, Scopus, ACM Digital Library, and PubMed databases. Then, studies published between 2015 and 2022 were selected. The review identified 1,991 studies. After applying inclusion, exclusion, and study quality assessment criteria, 26 primary studies were included in the final analysis. The results show different computational approaches, including countless Machine Learning algorithmic models, and three sub-areas of application in the context of syphilis: surveillance (61.54%), diagnosis (34.62%), and health policy evaluation (3.85%). These computational approaches are promising and capable of being tools to support syphilis control and surveillance actions