Mesenchymal stem cells engrafted in a fibrin scaffold stimulate Schwann cell reactivity and axonal regeneration following sciatic nerve tubulization

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

Peritoneal reactivity evaluation in horses subjected to experimental small colon enterotomy and treated with subcutaneous heparin

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

Cone-beam evaluation of pharyngeal airway space in class I, II, and III patients

The purpose of this study is to make a 3-dimensional (3-D) evaluation of the pharyngeal airway space (PAS) in patients with class I, II, and III malocclusion. Sixty patients were evaluated. The patients were divided in 3 groups according to their occlusion classification. The volume and area of PAS were evaluated using the software Dolphin 3-D Imaging in the preoperative period for orthognathic surgery. PAS volume and area were influenced by different patterns of malocclusion. The mean volume and area for class III patients were statistically bigger than for classes I and II patients (P < .001). There was also a significant difference for volume values between class I and II patients, being the bigger volume for the class I patients (P < .05). It was possible to conclude that the class III patients presented a bigger PAS compared with classes I and II patients.

Polymerization kinetics and reactivity of alternative initiators systems for use in light-activated dental resins

Objectives. The purpose of this study was to evaluate the reactivity and polymerization kinetics behavior of a model dental adhesive resin with water-soluble initiator systems. Methods. A monomer blend based on Bis-GMA, TEGDMA and HEMA was used as a model dental adhesive resin, which was polymerized using a thioxanthone type (QTX) as a photoinitiator. Binary and ternary photoinitiator systems were formulated using 1 mol% of each initiator. The co-initiators used in this study were ethyl 4-dimethylaminobenzoate (EDAB), diphenyliodonium hexafluorophosphate (DPIHFP), 1,3-diethyl-2-thiobarbituric acid (BARB), p-toluenesulfinic acid and sodium salt hydrate (SULF). Absorption spectra of the initiators were measured using a UV-Vis spectrophotometer, and the photon absorption energy (PAE) was calculated. The binary system camphorquinone (CQ)/amine was used as a reference group (control). Twelve groups were tested in triplicate. Fourier-transform infrared spectroscopy (FTIR) was used to investigate the polymerization reaction during the photoactivation period to obtain the degree of conversion (DC) and maximum polymerization rate (R-p(max)) profile of the model resin. Results. In the analyzed absorption profiles, the absorption spectrum of QTX is almost entirely localized in the UV region, whereas that of CQ is in the visible range. With respect to binary systems, CQ + EDAB exhibited higher DC and R-p(max) values. In formulations that contained ternary initiator systems, the group CQ + QTX + EDAB was the only one of the investigated experimental groups that exhibited an R-p(max) value greater than that of CQ + EDAB. The groups QTX + EDAB + DPIHFP and QTX + DPIHFP + SULF exhibited values similar to those of CQ + EDAB with respect to the final DC; however, they also exhibited lower reactivity. Significance. Water-soluble initiator systems should be considered as alternatives to the widely used CQ/amine system in dentin adhesive formulations. (C) 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Gas-phase reactivity of protonated 2-oxazoline derivatives: mass spectrometry and computational studies

RATIONALE: Oxazolines have attracted the attention of researchers worldwide due to their versatility as carboxylic acid protecting groups, chiral auxiliaries, and ligands for asymmetric catalysis. Electrospray ionization tandem mass spectrometric (ESI-MS/MS) analysis of five 2-oxazoline derivatives has been conducted, in order to understand the influence of the side chain on the gas-phase dissociation of these protonated compounds under collision-induced dissociation (CID) conditions. METHODS: Mass spectrometric analyses were conducted in a quadrupole time-of-flight (Q-TOF) spectrometer fitted with electrospray ionization source. Protonation sites have been proposed on the basis of the gas-phase basicity, proton affinity, atomic charges, and a molecular electrostatic potential map obtained on the basis of the quantum chemistry calculations at the B3LYP/6-31 + G(d, p) and G2(MP2) levels. RESULTS: Analysis of the atomic charges, gas-phase basicity and proton affinities values indicates that the nitrogen atom is a possible proton acceptor site. On the basis of these results, two main fragmentation processes have been suggested: one taking place via neutral elimination of the oxazoline moiety (99 u) and another occurring by sequential elimination of neutral fragments with 72 u and 27 u. These processes should lead to formation of R+. CONCLUSIONS: The ESI-MS/MS experiments have shown that the side chain could affect the dissociation mechanism of protonated 2-oxazoline derivatives. For the compound that exhibits a hydroxyl at the lateral chain, water loss has been suggested to happen through an E2-type elimination, in an exothermic step. Copyright (C) 2012 John Wiley & Sons, Ltd.

Profile of Trypanosoma cruzi Reactivity in a Population at High Risk for Endemic Pemphigus Foliaceus (Fogo Selvagem)

Fogo Selvagem (FS) is an autoimmune bullous disease with pathogenic IgG autoantibodies recognizing desmoglein 1 (Dsg1), a desmosomal glycoprotein. In certain settlements of Brazil, a high prevalence of FS (3%) is reported, suggesting environmental factors as triggers of the autoimmune response. Healthy individuals from endemic areas recognize nonpathogenic epitopes of Dsg1, and exposure to hematophagous insects is a risk factor for FS. Fogo selvagem and Chagas disease share some geographic sites, and anti-Dsg1 has been detected in Chagas patients. Indeterminate Chagas disease was identified in a Brazilian Amerindian population of high risk for FS. In counterpart, none of the FS patients living in the same geographic region showed reactivity against Trypanosoma cruzi. The profile of anti-Dsg1 antibodies showed positive results in 15 of 40 FS sera and in 33 of 150 sera from healthy individuals from endemic FS sites, and no cross-reactivity between Chagas disease and FS was observed.

The adipokine chemerin augments vascular reactivity to contractile stimuli via activation of the MEK-ERK1/2 pathway

Aims: Cytokines interfere with signaling pathways and mediators of vascular contraction. Endothelin-1 (ET-1) plays a major role on vascular dysfunction in conditions characterized by increased circulating levels of adipokines. In the present study we tested the hypothesis that the adipokine chemerin increases vascular contractile responses via activation of ET-1/ET-1 receptors-mediated pathways. Main methods: Male, 10-12 week-old Wistar rats were used. Endothelium-intact and endothelium-denuded aortic rings were incubated with chemerin (0.5 ng/mL or 5 ng/mL, for 1 or 24 h), and isometric contraction was recorded. Protein expression was determined by Western blotting. Key findings: Constrictor responses to phenylephrine (PE) and ET-1 were increased in vessels treated for 1 h with chemerin. Chemerin incubation for 24 h decreased PE contractile response whereas it increased the sensitivity to ET-1. Endothelium removal significantly potentiated chemerin effects on vascular contractile responses to PE and ET-1. Incubation with either an ERK1/2 inhibitor (PD98059) or ETA antagonist (BQ123) abolished chemerin effects on PE- and ET-1-induced vasoconstriction. Phosphorylation of MEK1/2 and ERK1/2 was significantly increased in vessels treated with chemerin for 1 and 24 h. Phosphorylation of these proteins was further increased in vessels incubated with ET-1 plus chemerin. ET-1 increased MEK1/2, ERK1/2 and MKP1 protein expression to values observed in vessels treated with chemerin. Significance: Chemerin increases contractile responses to PE and ET-1 via ERK1/2 activation. Our study contributes to a better understanding of the mechanisms by which the adipose tissue affects vascular function and, consequently, the vascular alterations present in obesity and related diseases. (c) 2012 Elsevier Inc. All rights reserved.

The use of nasal dilator strips as a placebo for trials evaluating continuous positive airway pressure

OBJECTIVES: The aim of the current study was to compare the objective and subjective effects of continuous positive airway pressure to the use of nasal dilator strips in patients with acromegaly and moderate to severe obstructive sleep apnea. METHODS: We studied 12 patients with acromegaly and moderate to severe obstructive sleep apnea (male/females = 8/4, age = 52 +/- 8 ys, body mass index = 33.5 +/- 4.6 Kg/m(2), apnea-hypopnea index = 38 +/- 14 events/h) who had been included in a randomized, crossover study to receive three months of treatment with continuous positive airway pressure and nasal dilator strips. All patients were evaluated at study entry and at the end of each treatment by polysomnography, and Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index and treatment satisfaction questionnaires. ClinicalTrials.gov: NCT01265121 RESULTS: The apnea-hypopnea index values decreased significantly with continuous positive airway pressure treatment but did not change with the use of nasal dilator strips. All of the subjective symptoms improved with both treatments, but these improvements were significantly greater with continuous positive airway pressure than with the nasal dilator strips. CONCLUSION: The use of nasal dilator strips had a much smaller effect on the severity of obstructive sleep apnea in patients with acromegaly and moderate to severe obstructive sleep apnea in comparison to the use of continuous positive airway pressure. Moreover, the improvement in several subjective parameters without any significant objective improvement in obstructive sleep apnea resulting from the use of nasal dilator strips is compatible with a placebo effect.

Extracellular matrix in airway smooth muscle is associated with dynamics of airway function in asthma

Background: Altered deposition of extracellular matrix (ECM) in the airway smooth muscle (ASM) layer as observed in asthma may influence ASM mechanical properties. We hypothesized that ECM in ASM is associated with airway function in asthma. First, we investigated the difference in ECM expression in ASM between asthma and controls. Second, we examined whether ECM expression is associated with bronchoconstriction and bronchodilation in vivo. Methods: Our cross-sectional study comprised 19 atopic mild asthma patients, 15 atopic and 12 nonatopic healthy subjects. Spirometry, methacholine responsiveness, deep-breath-induced bronchodilation (Delta R-rs) and bronchoscopy with endobronchial biopsies were performed. Positive staining of elastin, collagen I, III and IV, decorin, versican, fibronectin, laminin and tenascin in ASM was quantified as fractional area and mean density. Data were analysed using Pearson's or Spearman's correlation coefficient. Results: Extracellular matrix expression in ASM was not different between asthma and controls. In asthmatics, fractional area and mean density of collagen I and III were correlated with methacholine dose-response slope and DRrs, respectively (r = 0.71, P < 0.01; r = 0.60, P = 0.02). Furthermore, ASM collagen III and laminin in asthma were correlated with FEV1 reversibility (r = -0.65, P = 0.01; r = -0.54, P = 0.04). Conclusion: In asthma, ECM in ASM is related to the dynamics of airway function in the absence of differences in ECM expression between asthma and controls. This indicates that the ASM layer in its full composition is a major structural component in determining variable airways obstruction in asthma.

In vivo hydroquinone exposure causes tracheal hyperresponsiveness due to TNF secretion by epithelial cells

Hydroquinone (HQ) is the main oxidative substance in cigarette smoke and a toxic product of benzene biotransformation. Although the respiratory tract is an inlet pathway of HQ exposure, its effect on airway muscle responsiveness has not been assessed. We thus investigated the effects of low dose in vivo HQ-exposure on tracheal responsiveness to a muscarinic receptor agonist. Male Swiss mice were exposed to aerosolised 5% ethanol/saline solution (HQ vehicle; control) or 0.04 ppm HQ (1 h/day for 5 days) and tracheal rings were collected 1 h after the last exposure. HQ exposure caused tracheal hyper-responsiveness to methacholine (MCh), which was abolished by mechanical removal of the epithelium. This hyperresponsiveness was not dependent on neutrophil infiltration, but on tumour necrosis factor (TNF) secretion by epithelial cells. This conclusion was based on the following data: (1) trachea from HQ-exposed mice presented a higher amount of TNF, which was abrogated following removal of the epithelium; (2) the trachea hyperresponsiveness and TNF levels were attenuated by in vivo chlorpromazine (CPZ) treatment, an inhibitor of TNF synthesis. The involvement of HQ-induced TNF secretion in trachea mast cell degranulation was also demonstrated by the partial reversion of tracheal hyperresponsiveness in sodium cromoglicate-treated animals, and the in vivo HQ-exposure-induced degranulation of trachea connective tissue and mucosal mast cells, which was reversed by CPZ treatment. Our data show that in vivo HQ exposure indirectly exacerbates the parasympathetic-induced contraction of airway smooth muscle cells, mediated by TNF secreted by tracheal epithelial cells, clearly showing the link between environmental HQ exposure and the reactivity of airways. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Effects of aerobic exercise on chronic allergic airway inflammation and remodeling in guinea pigs

We evaluated the effects of aerobic exercise (AE) on airway inflammation, exhaled nitric oxide levels (ENO), airway remodeling, and the expression of Thl, Th2 and regulatory cytokines in a guinea pig asthma model. Animals were divided into 4 groups: non-trained and non-sensitized (C), non-sensitized and AE (AE), ovalbumin-sensitized and non-trained (OVA), and OVA-sensitized and AE (OVA + AE). OVA inhalation was performed for 8 weeks, and AE was conducted for 6 weeks beginning in the 3rd week of OVA sensitization. Compared to the other groups, the OVA + AE group had a reduced density of eosinophils and lymphocytes, reduced expression of interleukin (IL)-4 and IL-13 and an increase in epithelium thickness (p < 0.05). AE did not modify airway remodeling or ENO in the sensitized groups (p > 0.05). Neither OVA nor AE resulted in differences in the expression of IL-2, IFN-gamma, IL-10 or IL1-ra. Our results show that AE reduces the expression of Th2 cytokines and allergic airway inflammation and induces epithelium remodeling in sensitized guinea pigs. (c) 2012 Elsevier B.V. All rights reserved.

Rho-kinase inhibition attenuates airway responsiveness, inflammation, matrix remodeling, and oxidative stress activation induced by chronic inflammation

Possa SS, Charafeddine HT, Righetti RF, da Silva PA, Almeida-Reis R, Saraiva-Romanholo BM, Perini A, Prado CM, Leick-Maldonado EA, Martins MA, Tiberio ID. Rho-kinase inhibition attenuates airway responsiveness, inflammation, matrix remodeling, and oxidative stress activation induced by chronic inflammation. Am J Physiol Lung Cell Mol Physiol 303: L939-L952, 2012. First published September 21, 2012; doi:10.1152/ajplung.00034.2012.-Several studies have demonstrated the importance of Rho-kinase in the modulation of smooth muscle contraction, airway hyperresponsiveness, and inflammation. However, the effects of repeated treatment with a specific inhibitor of this pathway have not been previously investigated. We evaluated the effects of repeated treatment with Y-27632, a highly selective Rho-kinase inhibitor, on airway hyperresponsiveness, oxidative stress activation, extracellular matrix remodeling, eosinophilic inflammation, and cytokine expression in an animal model of chronic airway inflammation. Guinea pigs were subjected to seven ovalbumin or saline exposures. The treatment with Y-27632 (1 mM) started at the fifth inhalation. Seventy-two hours after the seventh inhalation, the animals' pulmonary mechanics were evaluated, and exhaled nitric oxide (E-NO) was collected. The lungs were removed, and histological analysis was performed using morphometry. Treatment with Y-27632 in sensitized animals reduced E-NO concentrations, maximal responses of resistance, elastance of the respiratory system, eosinophil counts, collagen and elastic fiber contents, the numbers of cells positive for IL-2, IL-4, IL-5, IL-13, inducible nitric oxide synthase, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, transforming growth factor-beta, NF-kappa B, IFN-gamma, and 8-iso-prostaglandin F2 alpha contents compared with the untreated group (P < 0.05). We observed positive correlations among the functional responses and inflammation, remodeling, and oxidative stress pathway activation markers evaluated. In conclusion, Rho-kinase pathway activation contributes to the potentiation of the hyperresponsiveness, inflammation, the extracellular matrix remodeling process, and oxidative stress activation. These results suggest that Rho-kinase inhibitors represent potential pharmacological tools for the control of asthma.

Ethanol Consumption Alters the Expression and Reactivity of Adrenomedullin in the Rat Mesenteric Arterial Bed

Aims: Adrenomedullin (AM) is a peptide that displays cardiovascular protective activity. We investigated the effects of chronic ethanol consumption on arterial blood pressure, vascular reactivity to AM and the expression of AM system components in the rat mesenteric arterial bed (MAB). Methods: Male Wistar rats were treated with ethanol (20% vol/vol) for 6 weeks. Systolic, diastolic and mean arterial blood pressure were monitored in conscious rats. Vascular reactivity experiments were performed on isolated rat MAB. Matrix metalloproteinase-2 (MMP-2) levels were determined by gelatin zymography. Nitrite and nitrate generation were measured by chemiluminescence. Protein and mRNA levels of pre-pro-AM, CRLR (calcitonin receptor-like receptor) and RAMP1, 2 and 3 (receptor activity-modifying proteins) were assessed by western blot and quantitative real-time polymerase chain reaction, respectively. Results: Ethanol consumption induced hypertension and decreased the relaxation induced by AM and acetylcholine in endothelium-intact rat MAB. Phenylephrine-induced contraction was increased in endothelium-intact MAB from ethanol-treated rats. Ethanol consumption did not alter basal levels of nitrate and nitrite, nor did it affect the expression of MMP-2 or the net MMP activity in the rat MAB. Ethanol consumption increased mRNA levels of pre-pro-AM and protein levels of AM in the rat MAB. Finally, no differences in protein levels or mRNA of CRLR and RAMP1, 2 and 3 were observed after treatment with ethanol. Conclusion: Our study demonstrates that ethanol consumption increases blood pressure and the expression of AM in the vasculature and reduces the relaxation induced by this peptide in the rat MAB.

Does the neonatal clinical risk for illness severity influence pain reactivity and recovery in preterm infants?

Background: The biobehavioural pain reactivity and recovery of preterm infants in the neonatal period may reflect the capacity of the central nervous system to regulate neurobiological development. Objective: The aim of the present study was to analyse the influence of the neonatal clinical risk for illness severity on biobehavioural pain reactivity in preterm infants. Methods: Fifty-two preterm infants were allocated into two groups according to neonatal severity of illness, as measured by the Clinical Risk Index for Babies (CRIB). The low clinical risk (LCr) group included 30 neonates with CRIB scores <4, and the high clinical risk (HCr) group included 22 neonates with CRIB scores >= 4. Pain reactivity was assessed during a blood collection, which was divided into five phases (baseline, antisepsis, puncture, recovery-dressing and recovery-resting). Behavioral pain reactivity was measured using the scores, and magnitude of responses in Neonatal Facial Coding System (NFCS) and Sleep-Wake States Scale (SWS). The heart rate was continuously recorded. Results: The HCr demonstrated a higher magnitude of response on the SWS score from the baseline to the puncture phase than the LCr. Also, the HCr exhibited a higher mean heart rate and minimum heart rate than the LCr in the recovery-resting phase. In addition, the HCr exhibited a higher minimum heart rate from the baseline to the recovery-resting phase than the LCr. Conclusion: The infants exhibiting a high neonatal clinical risk showed high arousal during the puncture procedure and higher physiological reactivity in the recovery phase.

Inflammation and circulating endothelial progenitor cells in patients with coronary artery disease and residual platelet reactivity

Sao Paulo Research Foundation [FAPESP/05/57710-3]