8-Hydroxy-2-(1H-1,2,3-triazol-1-yl)-1,4-naphtoquinone derivatives inhibited P2X7 Receptor-Induced dye uptake into murine Macrophages.

Extracellular adenosine 5'-triphosphate (ATP) triggers the P2X7 receptor (P2X7R) ionic channel to stimulate the release of the interleukin-IL-1ß cytokine into macrophages. The current study explored the reaction of six structurally diverse triazole derivatives on P2X7-mediated dye uptake into murine peritoneal macrophages. P2X7R activity determined by ATP-evoked fluorescent dye uptake. Triazole derivatives toxicity measured using dextran rhodamine exclusion based colorimetric assay. A740004 and BBG, both P2X7R antagonist, inhibited ATP-induced dye uptake. In contrast, the derivatives 5a, 5b, 5e, and 5f did not diminish P2X7R activity in concentrations until 100 µM. 5c and 5d analogs caused a potent inhibitory activity on P2X7-induced dye uptake. Dextran Rhodamine exclusion measurements after 24 h of continuous treatment with triazole derivatives indicated a moderated toxicity for all molecules. In conclusion, this study showed that a series of new hybrid 1,2,3-triazolic naphthoquinones reduces P2X7R-induced dye uptake into murine macrophages. In silico analysis indicates a good pharmacokinetic profile and molecular docking results of these analogs indicate the potential to bind into an allosteric site located into the P2X7R pore and juxtaposed with the ATP binding pocket. In this manner, the compounds 5c and 5d may be used as a scaffold for new P2X7R inhibitors with reduced toxicity, and good anti-inflammatory activity.

Structure-activity relationship, molecular docking, and molecular dynamic studies of diterpenes from marine natural products with anti-HIV activity.

HIV-1 infection is a global epidemic whose treatment is limited majorly by viral resistance and adverse effects. Natural products from algae have been studied for many years, including antiviral, being an alternative to anti-HIV drug design. Since the isolation of natural products can be a hurdle, molecular modeling is an important tool to study these compounds. Herein, structure-activity relationship, molecular docking, and molecular dynamic studies were performed to direct the studies of ten marine natural products with anti-HIV activity. In the structure-activity relationship, descriptors were identified associating the anti-HIV activity of five diterpenes with possible action on the reverse transcriptase allosteric site. These diterpenes were evaluated by molecular docking, and it was identified that only dolabelladienetriol interacted in the allosteric site. Molecular dynamics suggested that the dolabelladienetriol might interfere with the viral RNA binding to HIV-1 RT by inducing a conformational change of the enzyme. Also, in silico ADMET simulations predicts that the dolabelladienetriol present a high potential to be successfully developed as a drug. Thus, applying in silico approaches was possible to suggest potential anti-HIV compounds derived from marine natural products.Communicated by Ramaswamy H. Sarma.

Pulp calcification in traumatized primary teeth: prevalence and associated factors.

AIM: To establish the prevalence of pulp calcifications in 946 patients at the Research and Clinical Center of Dental Trauma in Primary Teeth. STUDY DESIGN: The clinical and radiographic records of l675 traumatized primary teeth were evaluated. Statistical analysis was performed using chi-square and univariate logistic regression. RESULTS: 197 (20.8%) patients showed pulp calcification (PC). A total of 250 (14.9%) calcified teeth were observed In most teeth, PC appeared within the first 12 months following trauma. PC prevalence was higher in cases of repeated trauma (29.6%) than in single trauma (16.4%), p < 0.05, with a 2.14 chance of showing pulp calcification when a child suffered recurrent trauma. Most teeth showing calcified pulp, suffered trauma to the supportive tissue (67.4%), being statistically significant in relation to the trauma to dental tissue (p < 0.05). CONCLUSION: PC is a sequelae in cases of trauma to the primary dentition; teeth that suffered recurrent traumatic injuries show higher risk of presenting.

1,4-Naphthoquinones potently inhibiting P2X7 receptor activity.

P2X7 receptor (P2X7R) is an ATP-gated ion-channel with potential therapeutic applications. In this study, we prepared and searched a series of 1,4-naphthoquinones derivatives to evaluate their antagonistic effect on both human and murine P2X7 receptors. We explored the structure-activity relationship and binding mode of the most active compounds using a molecular modeling approach. Biological analysis of this series (eight analogues and two compounds) revealed significant in vitro inhibition against both human and murine P2X7R. Further characterization revealed that AN-03 and AN-04 had greater potency than BBG and A740003 in inhibiting dye uptake, IL-1ß release, and carrageenan-induced paw edema in vivo. Moreover, we used electrophysiology and molecular docking analysis for characterizing AN-03 and AN-04 action mechanism. These results suggest 1,4-napthoquinones, mainly AN-04, as potential leads to design new P2X7R blockers and anti-inflammatory drugs.

HIV-1 reverse transcriptase: a therapeutical target in the spotlight.

Human Immunodeficiency Virus type 1 Reverse Transcriptase (HIV-1 RT) is one of the most important targets for treatment of Acquired Immune Deficiency Syndrome (AIDS). It catalyzes the reverse transcription of HIV-RNA into a double stranded DNA, and the knowledge of its substrate specificity and catalytic mechanism has guided the development of several inhibitors widely used on current HIV/AIDS therapy. However, mutations in HIV-1 RT structure can lead to the emergence of drug-resistant virus strains. The goal of this review is to summarize relevant structural features of HIV-1 RT and its inhibitors in such a way that this cost-effective target in the development of new antiretroviral drugs is particularly highlighted.

Molecular dynamics simulations of the free and inhibitor-bound cruzain systems in aqueous solvent: insights on the inhibition mechanism in acidic pH.

The major cysteine protease of Trypanosoma cruzi, cruzain (CRZ), has been described as a therapeutic target for Chagas' disease, which affects millions of people worldwide. Thus, a series of CRZ inhibitors has been studied, including a new competitive inhibitor, Nequimed176 (NEQ176). Nevertheless, the structural and dynamic basis for CRZ inhibition remains unclear. Hoping to contribute to this ever-growing understanding of timescale dynamics in the CRZ inhibition mechanism, we have performed the first study using 100 ns of molecular dynamics (MD) simulations of two CRZ systems in an aqueous solvent under pH 5.5: CRZ in the apo form (ligand free) and CRZ complexed to NEQ176. According to the MD simulations, the enzyme adopts an open conformation in the apo form and a closed conformation in the NEQ176-CRZ complex. We also suggest that this closed conformation is related to the hydrogen-bonding interactions between NEQ176 and CRZ, which occurs through key residues, mainly Gly66, Met68, Asn69, and Leu160. In addition, the cross-correlation analysis shows evidence of the correlated motions among Ala110-Asp140, Leu160-Gly189, and Glu190-Gly215 subdomains, as well as, the movements related to Ala1-Thr59 and Asp60-Pro90 regions seem to be crucial for CRZ activity.

Analysis of worldwide sequence mutations in Zika virus proteins E, NS1, NS3 and NS5 from a structural point of view.

Zika virus (ZIKV) is an emergent arbovirus that has attracted attention in the last year as a possible causative agent of congenital malformation; it shows a remarkably increased microcephaly risk during otherwise healthy pregnancies. We present here an analysis of all ZIKV sequences available in Genbank up to April 2016, studying the mutations in the whole polyprotein and their possible structural implications for the proteins E, NS1, NS3 and NS5. This study suggests that microcephaly is not a consequence of any particular amino acid substitution but, conceivably, is a feature of ZIKV itself. Moreover, the structural analysis of ZIKV proteins, together with the mutational landscape of ZIKV and a structure-sequence comparison with other flaviviruses, allows the suggestion of regions that could be exploited as anti-ZIKV targets, including some allosteric sites found in the NS3 and NS5 proteins of DENV.

In vitro occlusal wear of restorative materials on primary teeth.

Since primary tooth enamel wears more rapidly than permanent tooth enamel, it is important to study the mechanical wear patterns of restorative materials used in the primary dentition. It is important that an in vitro evaluation of wear resistance of different restorative materials is done in order to establish a valid in vitro test protocol for use in pediatric dentistry.

Physiological adjustment to salt stress in Jatropha curcas is associated with accumulation of salt ions, transport and selectivity of K+, osmotic adjustment and K+/Na+ homeostasis.

This study assessed the capacity of Jatropha curcas to physiologically adjust to salinity. Seedlings were exposed to increasing NaCl concentrations (25, 50, 75 and 100 mm) for 15 days. Treatment without NaCl was adopted as control. Shoot dry weight was strongly reduced by NaCl, reaching values of 35% to 65% with 25 to 100 mm NaCl. The shoot/root ratio was only affected with 100 mm NaCl. Relative water content (RWC) increased only with 100 mm NaCl, while electrolyte leakage (EL) was much enhanced with 50 mm NaCl. The Na(+) transport rate to the shoot was more affected with 50 and 100 mm NaCl. In parallel, Cl(-) transport rate increased with 75 and 100 mm NaCl, while K(+) transport rate fell from 50 mm to 100 mm NaCl. In roots, Na(+) and Cl(-) transport rates fell slightly only in 50 mm (to Na(+)) and 50 and 100 mm (to Cl(-)) NaCl, while K(+) transport rate fell significantly with increasing NaCl. In general, our data demonstrate that J. curcas seedlings present changes in key physiological processes that allow this species to adjust to salinity. These responses are related to accumulation of Na(+) and Cl(-) in leaves and roots, K(+)/Na(+) homeostasis, transport of K(+) and selectivity (K-Na) in roots, and accumulation of organic solutes contributing to osmotic adjustment of the species.

Selective PGHS-2 inhibitors: a rational approach for treatment of the inflammation.

Prostaglandin-H synthase exists in two isoforms, PGHS-1 and PGHS-2. PGHS-1 is present and is constitutively expressed in most cells and tissues, whereas PGHS-2 is mainly thought to mediate inflammation. Selective prostaglandin-H synthase-2 (or cyclooxygenase-2) inhibitors have been shown to be potent antiinflammatory agents with fewer side effects than currently marketed nonsteroidal antiinflammatory drugs (NSAIDs). This review addresses the main classes of the selective PGHS-2 inhibitors whose selectivity is documented by supporting PGHS-1 and PGHS-2 enzyme data. In addition, we also describe our experience in design, synthesis and pharmacological in vivo evaluation of new 1,2-benzodioxole derivatives as candidate of the selective PGHS-2 inhibitors, with special attention to molecular dynamics simulations of these derivatives attached to the active site of PGHS-2.

Synthesis and pharmacological evaluation of novel heterotricyclic acylhydrazone derivatives, designed as PAF antagonists.

This paper describes the synthesis and the antiplatelet properties of new heterotricyclic N-acylhydrazone derivatives (7a-e), structurally analogous to known hetrazepinic PAF antagonists, exploring molecular hybridization as a tool for molecular designing. The synthetic route employed to access compounds (7a-e) used, as starting material, the previously described methyl 3-hydroxy-8-methyl-6-phenyl-6H-pyrazolo[3,4-b]thieno[2, 3-d]pyridine-2-carboxylate derivative. The results from inhibitory effects of these novel acylhydrazone derivatives (7a-e) upon PAF-induced platelet aggregation, indicated that all compounds present a significant antithrombotic profile.

Proposal of a new PAF pharmacophoric map by the AM1 method.

PAF is a powerful phospholipid-derived autacoid involved in many pathophysiological processes. Many PAF antagonists have been synthesized and assayed for therapeutic purposes. We have synthesized derivatives (5-7), structurally related to WEB 2086 (1), which were rationally designed based on a planar PAF receptor model previously described by Bures et al. (1994; J. Chem. Inf. Comput. Sci. 24, 218-223). However, pharmacological studies revealed that derivatives (5-7) were inactive as PAF antagonists. AM1 quantum calculations of classical PAF antagonists (1-4), as well as of our derivatives (5-7), demonstrated that electronic features alone are unable to explain the lack of the activity of (5-7). These results induced us to propose a new tridimensional PAF receptor pharmacophoric map by analyzing all stable conformations obtained for derivatives (1-4). The interpoint distances (D1-D5) revealed that the lowest-energy conformers of (5-7) had similar geometries to derivatives (1-4). So, these aspects could not explain the inactivity of the compounds (6-7). The proposed model suggests that the best fit of antagonist compounds may involve the participation of a sulfur atom electron lone pair adequately oriented in relation to the plane of a N-aromatic ring present in the compounds investigated.

Reliability of the Portuguese version of the structured clinical interview for DSM-III-R (SCID) in a Brazilian sample of psychiatric outpatients.

The objective of the present study was to determine the reliability of psychiatric diagnoses using a translation and adaptation of Portuguese of the "Structured Clinical Interview for DSM-III-R-patient version" (SCID-P) and the "Structured Clinical Interview for DSM-III-R Personality Disorders" (SCID-II), using the joint interviews methodology. Thirty-nine subjects were evaluated using the SCID-P and 20 of them using the SCID-II. Interrater reliability was analyzed statistically by means of the Kappa Coefficient. Agreement between results obtained with SCID-P was statistically significant for the major diagnostic categories of DSM-III-R and for 10 of the 12 specific diagnostic categories studied (a minimum of 4 subjects per diagnosis). Agreement was not statistically significant for Psychotic Disorder Not Otherwise Specified (NOS) and for Other Bipolar Disorder. The Weighted Kappa for the main diagnoses and the Overall Kappa for the entire set of 25 specific diagnostic categories proposed by the SCID-P were statistically significant. The general agreement for Personality Disorders with SCID-II was statistically significant. The Kappa Coefficient was determined for the Avoidant, Paranoid, Histrionic and Borderline Personality Disorders and for the Conduct Disorder. The remaining Personality Disorders were not analyzed statistically because of their low prevalence in the sample. Agreement was not significant only for the Histrionic Personality Disorder. These data suggest that the translation and adaptation of the SCID-P and SCID-II to Portuguese presents, in general, good reliability indices, and thus its use is recommended.

[The importance of the pediatrician in oral health care promotion]. / A importância do médico pediatra na promoção da saúde bucal.

The degree to which the pediatrician's knowledge might contribute to preventive dentistry is investigated. Questionnaires concerning aspects such as breastfeeding, diet, pacifier use, fluoride use, oral hygiene and the recommended moment for the first dental visit were sent to a random sample of 85 pediatricians in S. José dos Campos. Answers were received from 48 (56.4%) of them. Data showed that orientation about preventive dentistry was not a common procedure among the majority of the pediatricians, suggesting that better integration between physician and dentist is necessary if children are to grow up with better general and dental health.

[Prevalence of iron deficiency anemia and risk indicators in children from 12 to 18 months attended at the outpatient clinic of Instituto de Puericultura e Pediatria Martagão Gesteira]. / Prevalência de anemia ferropriva e marcadores de risco associados em crianças entre 12 e 18 meses de idade atendidas nos Ambulatórios do Instituto de Puericultura e Pediatria Martagão Gesteira.

OBJECTIVES: The prevalence of iron deficiency anemia and the associated risk indicators were studied in children from 12 to 18 months at the outpatient unit of IPPMG, in order to evaluate and monitor the service. METHODS: This is a cross-sectional descriptive study of 288 children seen at the outpatient unit of IPPMG, from January to December 1993. Anemia was diagnosed by dosage of seric hemoglobin. The studied risk indicators were: prenatal care, birth weight, pediatric follow-up, socio-economic aspects, breast-feeding pattern, nutritional status, and iron prescription. Data were computerized and analyzed by EPIINFO and EGRET softwares. Statistical analysis was performed by Pearson chi(2), and breast-feeding pattern was analyzed by the Kaplan-Meier survival curves. RESULTS: Fifty percent of all children had anemia and 13.2% had severe anemia. Children had an early entry to follow-up at the clinic, and the number of consultations was adequate, according to the recommendations of the Ministry of Health. Only 27% of families had a "per capita" income above one minimum salary, although most had adequate housing and environmental conditions. The median duration of breast-feeding was 7.8 and of exclusive breast-feeding was 3.2 months. No association between anemia and income, early weaning, low-birth weight or undernutrition was found. CONCLUSION: The prevalence of anemia was extremely high, indicating the need for a specific monitoring system for the occurrence of iron deficiency anemia in this service.

Microleakage in primary teeth restored by conventional or bonded amalgam technique.

The aim of this in vitro study was to evaluate marginal leakage in class V restorations in primary teeth restored with amalgam, using three different techniques. Thirty maxillary anterior primary teeth, clinically sound and naturally exfoliated, were used. In group 1 (n = 10), two thin layers of a copal varnish (Cavitine) were applied. In group 2 (n = 10), Scotchbond Multi-Purpose Plus, a dual adhesive system, was used according to manufacturer instructions. In group 3 (n = 10), One-Step adhesive system in combination with a low-viscosity resin (Resinomer) were used according to manufacturer instructions. All samples were restored with a high-copper dental amalgam alloy (GS 80, SDI). After restoration, the samples were stored in normal saline at 37 degrees C for 72 h. The specimens were polished, thermocycled (500 cycles, 5 degrees and 55 degrees C, 30-s dwell time) and impermeabilized with fingernail polish to within 1.0 mm of the restoration margins. The teeth were then placed in 0.5% methylene blue for 4 h. Finally, the samples were sectioned and evaluated for marginal leakage. The Kruskal-Wallis test showed that the filled adhesive resin (group 3) had the least microleakage. There was no significant difference between groups 1 and 2.

Acute oral toxicity of Celtis iguanaea (Jacq. ) Sargent leaf extract (Ulmaceae) in rats and mice / Toxicidade oral aguda do extrato de folhas de Celtis iguanaea (Jacq. ) Sargent em ratos e camundongos

RESUMO Celtis iguanaea (Jacq.) Sargent is popularly used to treat urinary infections, kidneys, breast, body aches, rheumatism, asthma, cramps, poor digestion and as a diuretic medicine. This study aims to determine the acute toxicity of the aqueous leaf extract of Celtis iguanaea (Jacq.) Sargent in rodents. After the collection processes, identification, drying and grinding, the lyophilized powder of the leaves produced, by infusion, the aqueous extract and it was dissolved in saline 0.9%. The administration was made by gavage at a dose of 2000 mg kg-1to rats and mice of both genders. The oral toxicity was determined according to the OECD 423 guide. Signs of toxicity were observed for 15 days and classified from 0 to 4 respectively as missing, rare, mild, moderate and severe. The weight of the animals and the physiological parameters such as food intake and excrements production were observed. All animal tissue samples were collected for histological analysis. The extract was included in Type 5 (substance with LD50 higher than 2000 mg kg-1 and less than 5000 mg kg-1), being considered of low toxicity, but the histopathologycal findings suggested nephrotoxicity and cardiotoxicity. The absolute weight of the kidneys and the heart of the male rats and mice increased, but there was no significant raise in the relative weight of the animals’ organs.

RESUMO Celtis iguanaea (Jacq.) Sargent é uma planta usada popularmente para tratar infecções do trato urinário, rim, mama, dores no corpo, reumatismo, asma, cólicas, má digestão e também é usada como diurético. Este trabalho objetivou determinar a toxicidade aguda do extrato aquoso de folhas de Celtis iguanaea (Jacq.) Sargent em roedores. Após os processos de coleta, identificação, secagem e moagem, o pó liofilizado das folhas da planta foi utilizado para produzir o seu extrato aquoso por infusão e então dissolvido em solução salina a 0.9 %. A administração foi feita por gavagem na dose de 2000 mg kg-1 em ratos e camundongos de ambos os sexos. A toxicidade oral foi determinada de acordo com o guia 423 da OECD. Sinais de toxicidade foram observados por 15 dias e tabulados de 0 a 4, respectivamente, como ausentes, raros, leves, moderados e graves. Foi acompanhado o peso dos animais e parâmetros fisiológicos tais como alimentação e excreções. Amostras do tecido de todo o animal foram coletadas para análise histológica. A toxicidade encontrada para o extrato foi incluída na classe 5 (substâncias com DL50 superior a 2000 mg kg-1 e menor que 5000 mg kg-1) sendo considerada baixa, porém, as observações histopatológicas sugerem nefrotoxicidade e cardiotoxicidade. O peso absoluto dos rins e coração de ratos e camundongos machos aumentou, porém, não houve aumento significativo no peso relativo dos órgãos dos animais.

Antiplatelet activity and structure-activity relationship study of Pyrazolopyridine Derivatives as potential series for treating thrombotic diseases.

AIM: Platelets plays a central role in hemostatic processes and consequently are similarly involved in pathological processes, such as arterial thrombosis and atherosclerosis. Herein we described the synthesis, antiplatelet profile and structure-activity relationship (SAR) of a new series of N'-substitutedphenylmethylene-1H-pyrazolo[3,4-b]pyridine-carbohydrazide derivatives (3a-3k). METHODS: These compounds were synthesized in good yield and tested in platelet aggregation assays using collagen, ADP and arachidonic acid as agonists. We also performed a SAR studies using SPARTAN' 08 program, in silico ADMET screening and the Lipinski " rule of five " using Osiris Property Explorer and molinspiration on-line programs. RESULTS: Interestingly, the new compounds were active against collagen and arachidonic acid (AA) with the two most actives compounds (3a and 3c - IC(50)=61 microM and 68 microM respectively) almost 5-fold more potent than aspirin (IC(50)=300 microM). These derivatives showed low theoretical toxicity risks in in silico ADMET screening and fulfilled the Lipinski rule of five, suggesting good oral biodisponibility. CONCLUSION: This work showed carbohydrazide group as potential for designing new antiplatelets. On that purpose, 3a and 3c may act as prototypes to generate more efficient and safe molecules for treating thrombotic diseases.

Fluorescence of primary dentine after chemomechanical and conventional rotary excavation.

AIM: This was to compare fluorescence values of dentine remaining after caries removal using chemomechanical systems and conventional rotary methods. STUDY DESIGN: In vitro study. METHODS: 30 extracted primary teeth with proximal carious cavities were divided into three groups according to caries removal method: Carisolv, Papacarie and conventional low speed rotary burs. Carious (initial) and remaining (final) dentine evaluations were assessed by visual-tactile examination and DIAGNOdent. Transversal microhardness (TMH) of remaining dentine was evaluated. Fluorescence and TMH values were submitted to two-way ANOVA and the post hoc Tukey test (alpha = 0.05) and Pearson's linear correlation. RESULTS: Two-way ANOVA revealed that fluorescence values were similar between conventional rotary excavation, Carisolv and Papacarie groups (p = 0.0542). No statistically significant differences (p = 0.1147) were found to TMH values. No correlation was found between fluorescence and TMH values (r = -0.0273). CONCLUSION: All caries excavation methods resulted in similar remaining dentine fluorescence values. No correlation was found between fluorescence values and TMH of remaining dentine.