Morphologic changes and the expression of alpha-melanocyte stimulating hormone and melanocortin-1 receptor in melasma lesions: A comparative study

Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light- to dark-brown macules on sun-exposed skin areas. The literature shows few studies on its physiopathogeny. However, changes in α-melanocyte stimulating hormone (α-MSH) secretion and melanocortin-1 receptor (MC1-R) expression may play a role to trigger this condition. Biopsies were taken from both melasma skin and adjacent perilesional normal skin of 44 patients. The biopsies were submitted for hematoxylin and eosin and Fontana-Masson staining and immunohistochemistry with Melan-A, α-MSH, and MC1-R, and processed for transmission electron microscopy. In some cases, they were submitted to MC1-R gene expression analysis by real-time polymerase chain reaction. Increased lymphohistiocytic infiltrate and solar elastosis, higher epidermal melanin were observed in melasma skin. Electron microscopy revealed a greater number of mature melanosomes in keratinocytes and melanocytes, and more prominent cytoplasmic organelles in melasma skin. There was no difference in melanocyte number between areas. However, melanocytes were larger and more dendritic in melasma skin. Immunohistochemistry with α-MSH and MC1-R showed significant labeling in melasmic epidermis but MC1-R messenger ribonucleic acid (RNAm) did not show significant quantitative difference between melasma and normal skin. © 2010 by Lippincott Williams & Wilkins.

Cinnamic acid is partially involved in propolis immunomodulatory action on human monocytes

Propolis is a beehive product used in traditional medicine due to its biological properties. It shows a complex chemical composition including phenolics, such as cinnamic acid (Ci). The mechanisms of action of propolis have been the subject of research recently; however, the involvement of Ci on propolis activity was not investigated on immune cells. Ci effects were evaluated on human monocytes, assessing the expression of Toll-like receptors (TLRs), HLA-DR, and CD80. Cytokine production (TNF-α and IL-10) and the fungicidal activity of monocytes were evaluated as well. Data showed that Ci downregulated TLR-2, HLA-DR, and CD80 and upregulated TLR-4 expression by human monocytes. High concentrations of Ci inhibited both TNF-α and IL-10 production, whereas the same concentrations induced a higher fungicidal activity against Candida albicans. TNF-α and IL-10 production was decreased by blocking TLR-4, while the fungicidal activity of monocytes was not affected by blocking TLRs. These results suggest that Ci modulated antigen receptors, cytokine production, and the fungicidal activity of human monocytes depending on concentration, and TLR-4 may be involved in its mechanism of action. Ci seemed to be partially involved in propolis activities. © 2013 Bruno José Conti et al.

Diversity and three-dimensional structures of the alpha Mcr of the methanogenic Archaea from the anoxic region of Tucuruí Lake, in Eastern Brazilian Amazonia

ABSTRACT: Methanogenic archaeans are organisms of considerable ecological and biotechnological interest that produce methane through a restricted metabolic pathway, which culminates in the reaction catalyzed by the Methyl-coenzyme M reductase (Mcr) enzyme, and results in the release of methane. Using a metagenomic approach, the gene of the a subunit of mcr (mcrα) was isolated from sediment sample from an anoxic zone, rich in decomposing organic material, obtained from the Tucuruí hydroelectric dam reservoir in eastern Brazilian Amazonia. The partial nucleotide sequences obtained were 83 to 95% similar to those available in databases, indicating a low diversity of archaeans in the reservoir. Two orders were identified -the Methanomicrobiales, and a unique Operational Taxonomic Unit (OTU) forming a clade with the Methanosarcinales according to low bootstrap values. Homology modeling was used to determine the three-dimensional (3D) structures, for this the partial nucleotide sequence of the mcrα were isolated and translated on their partial amino acid sequences. The 3D structures of the archaean mcrα observed in the present study varied little, and presented approximately 70% identity in comparison with the mcrα of Methanopyrus klanderi. The results demonstrated that the community of methanogenic archaeans of the anoxic C1 region of the Tucurui reservoir is relatively homogeneous.

Rapid preparation of alpha-FeOOH and alpha-Fe2O3 nanostructures by microwave heating and their application in electrochemical sensors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of Dextrose and Lipopolysaccharide on the Corrosion Behavior of a Ti-6Al-4V Alloy with a Smooth Surface or Treated with Double-Acid-Etching

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bond strength of composite to dentin: effect of acid etching and laser irradiation through an uncured self-etch adhesive system

This study evaluated the effect on micro-tensile bond strength (mu-TBS) of laser irradiation of etched/unetched dentin through an uncured self-etching adhesive. Dentinal surfaces were treated with Clearfil SE Bond Adhesive (CSE) either according to the manufacturer's instructions (CSE) or without applying the primer (CSE/NP). The dentin was irradiated through the uncured adhesive, using an Nd: YAG laser at 0.75 or 1 W power settings. The adhesive was cured, composite crowns were built up, and the teeth were sectioned into beams (0.49 mm(2)) to be stressed under tension. Data were analyzed using one-way ANOVA and Tukey statistics (alpha = 5%). Dentin of the fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). The results showed that non-etched irradiated surfaces presented higher mu-TBS than etched and irradiated surfaces (p < 0.05). Laser irradiation alone did not lead to differences in mu-TBS (p > 0.05). SEM showed solidification globules on the surfaces of the specimens. The interfaces were similar on irradiated and non-irradiated surfaces. Laser irradiation of dentin through the uncured adhesive did not lead to higher mu-TBS when compared to the suggested manufacturer's technique. However, this treatment brought benefits when performed on unetched dentin, since bond strengths were higher when compared to etched dentin.

Effect of Chlorogenic Acid (5-Caffeoylquinic Acid) Isolated from Baccharis oxyodonta on the Structure and Pharmacological Activities of Secretory Phospholipase A2 from Crotalus durissus terrificus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caffeic Acid Phenethyl Ester: Consequences of Its Hydrophobicity in the Oxidative Functions and Cytokine Release by Leukocytes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Improvement of Pro-Oxidant Capacity of Protocatechuic Acid by Esterification

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Endogenous and uric acid-induced activation of NLRP3 inflammasome in pregnant women with preeclampsia

Preeclampsia (PE) is a specific syndrome of pregnancy, characterized by hypertension and proteinuria. This pathology is associated with hyperuricemia and elevated serum levels of inflammatory cytokines. Uric acid crystals may activate an intracellular complex called inflammasome, which is important for processing and release of inflammatory cytokines. This study investigated the state of monocyte activation, both endogenous and stimulated with monosodium urate (MSU), by gene expression of NLRP1 and NLRP3 receptors as well as their association with inflammatory cytokines expression. Monocytes were obtained from peripheral blood of 23 preeclamptic pregnant women, 23 normotensive pregnant women (NT) and 23 healthy non-pregnant women (NP). Inflammasome activation was evaluated by the gene expression of NLRP1, NLRP3, caspase-1, IL-1 beta, IL-18 and TNF-alpha by RT-qPCR in unstimulated monocytes (endogenous expression), or after cell stimulation with MSU (stimulated expression). The concentration of cytokines was assessed by ELISA. In preeclamptic pregnant women, gene expression of NLRP1, NLRP3, caspase-1, IL-1 beta and TNF-alpha by monocytes stimulated or not with MSU was significantly higher than in NT and NP groups. Stimulation of monocytes from preeclamptic and non-pregnant women with MSU induced increased gene expression of NLRP3, caspase-1 and TNF-alpha in relation to the endogenous expression in these groups, while this was not observed in the NT group. The cytokine determination showed that monocytes from women with PE produced higher endogenous levels of IL-1 beta, IL-18 and TNF-alpha compared to the other groups, while the stimulus with MSU led to higher production of these cytokines in preeclamptic group than in the NT group. In conclusion, the results showed increased basal gene expression of NLRP1 and NLRP3 receptors in monocytes from PE group. These cells stimulation with MSU demonstrates that uric acid plays a role in NLRP3 inflammasome activation, suggesting the participation of this inflammatory complex in the pathogenesis of preeclampsia.

Surface degradation of lithium disilicate ceramic after immersion in acid and fluoride solutions

Purpose: To analyze whether immersion in sodium fluoride (NaF) solutions and/or common acidic beverages (test solutions) would affect the surface roughness or topography of lithium disilicate ceramic. Methods: 220 ceramic discs were divided into four groups, each of which was subdivided into five subgroups (n = 11). Control group discs were immersed in one of four test beverages for 4 hours daily or in artificial saliva for 21 days. Discs in the experimental groups were continuously immersed in 0.05% NaF, 0.2% NaF, or 1.23% acidulated phosphate fluoride (APF) gel for 12, 73, and 48 hours, respectively, followed by immersion in one of the four test beverages or artificial saliva. Vickers microhardness, surface roughness, scanning electron microscopy (SEM) associated with energy dispersive spectroscopy, and atomic force microscopy (AFM) assessments were made. Data were analyzed by nested analysis of variance (ANOVA) and Tukey's test (alpha = 0.05). Results: Immersion in the test solutions diminished the microhardness and increased the surface roughness of the discs. The test beverages promoted a significant reduction in the Vickers microhardness in the 0.05% and 0.2% NaF groups. The highest surface roughness results were observed in the 0.2% NaF and 1.23% APF groups, with similar findings by SEM and AFM. Acidic beverages affected the surface topography of lithium disilicate ceramic. Fluoride treatments may render the ceramic surface more susceptible to the chelating effect of acidic solutions.

A conjugate of the lytic peptide Hecate and gallic acid: structure, activity against cervical cancer, and toxicity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hydrophobicity and antioxidant activity acting together for the beneficial health properties of nordihydroguaiaretic acid

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determinação sérica de haptoglobina, ceruloplasmina, alpha(1)-glicoproteína ácida, transferrina e alpha(1)-antitripsina, em equinos com cólica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rheological characterisation and effect of abiotic factors on the antimicrobial efficacy of chitosan-based hidrogels containing alpha-hydroxy acids

The aim of this study was to investigate the rheological properties and antibacterial efficacy of chitosan/ alpha-hydroxy acids (lactic acid and glycolic acid) and cellulose polymers, both in hydrogels, in order to produce a formulation with improved activity against Propionibacterium acnes and Staphylococcus aureus, which can potentially be used in the treatment of acne. The rheological characterisation of the hydrogels was examined using continuous shear and viscoelastic creep. The antibacterial activities of formulations were performed by the well diffusion and broth microdilution. The hydrogels formulated with only chitosan showed pseudoplastic behavior while the chitosan hydrogels with cellulose polymers presented viscoelastic properties. The antibacterial activity was proportional to AHA and chitosan concentration. It was enhanced at low pH values and with high molecular weight chitosan and did not change with the incorporation of two cellulose polymers. The antibacterial mechanism of chitosan has currently been hypothesized as being related to surface interference. The results show that chitosan - based hydrogels containing AHA and cellulose polymers are viscoelastic,indicating good applicability onto the skin, and they present bacterial activity under various experimental conditions.