The stimulation of peripheral nerve regeneration has been studied in different ways, including the use of electrical fields. The capacity of this modality to enhance nerve regeneration is influenced by the parameters used, including current type, frequency, intensity, and means of administration. Transcutaneous electrical nerve stimulation (TENS) is a frequently used form of administering electrical current to the body, but its effects on peripheral nerve regeneration are not known.
View Article and Find Full Text PDFIn this work, we present the first application to a protein of the stochastic constant-pH molecular dynamics (MD) method with the inclusion of proton tautomerism. The acidic titration of HEWL was performed under different conditions. Both generalized reaction field (GRF) and particle mesh Ewald (PME) methods were used in the treatment of the long range electrostatics and, even though the PME simulations revealed to be more stable, the better results were obtained using GRF (pK(a) RMSD of 0.
View Article and Find Full Text PDFThe correlation between protein motions and function is a central problem in protein science. Several studies have demonstrated that ligand binding and protein dynamics are strongly correlated in intracellular lipid binding proteins (iLBPs), in which the high degree of flexibility, principally occurring at the level of helix-II, CD, and EF loops (the so-called portal area), is significantly reduced upon ligand binding. We have recently investigated by NMR the dynamic properties of a member of the iLBP family, chicken liver bile acid binding protein (cL-BABP), in its apo and holo form, as a complex with two bile salts molecules.
View Article and Find Full Text PDFBackground: Venom immunotherapy (VIT) induces long-lasting immune tolerance to hymenoptera venom antigens, but the underlying mechanisms are not yet clarified. Regulatory T cells are thought to play an important role in allergic diseases and tolerance induction during specific immunotherapy.
Aim: Characterize longitudinally the impact of VIT on the pool of circulating regulatory T cells.
Correct folding is critical for the biological activities of proteins. As a contribution to a better understanding of the protein (un)folding problem, we studied the effect of temperature and of urea on peptostreptococcal Protein L destructuration. We performed standard molecular dynamics simulations at 300 K, 350 K, 400 K, and 480 K, both in 10 M urea and in water.
View Article and Find Full Text PDFA comprehensive study of the thermodynamic redox behavior of the hemes of the ba3 enzyme from Thermus thermophilus, a B-type heme-copper oxygen reductase, is presented. This enzyme, in contrast to those having a single type of heme, allows the B- and A-type hemes to be monitored separately by visible spectroscopy and the reduction potential of each heme to be determined unequivocally. The relative order of the midpoint reduction potentials of each center changed in the pH range from 6 to 8.
View Article and Find Full Text PDFA comprehensive study of the thermodynamic redox behavior of the hemes from the cbb3 oxygen reductase from Bradyrhizobium japonicum was performed. This enzyme is a member of the C-type heme-copper oxygen reductase superfamily and has three subunits with six redox centers: four low-spin hemes and a high-spin heme and one copper ion, composing the site where oxygen is reduced. In this analysis, the visible spectra and redox properties of the five heme centers were deconvoluted.
View Article and Find Full Text PDFLactococcus lactis FI9078, a construct carrying a disruption of the ldh gene, converted approximately 90% of glucose into lactic acid, like the parental strain MG1363. This unexpected lactate dehydrogenase activity was purified, and ldhB was identified as the gene encoding this protein. The activation of ldhB was explained by the insertion of an IS905-like element that created a hybrid promoter in the intergenic region upstream of ldhB.
View Article and Find Full Text PDFWe present here a theoretical study to investigate possible proton pathways in the [NiFe]-hydrogenase from Desulfovibrio gigas. The approach used in this study consists of a combination of Poisson-Boltzmann and Monte Carlo simulations together with a distance-based network analysis to find possible groups involved in the proton transfer. Results obtained at different pH values show a reasonable number of proton active residues distributed by the protein interior and surface, with a concentration around the metal centres.
View Article and Find Full Text PDFPoor communities in Rio de Janeiro, which are known as favelas, suffer from various problems related to poor housing, poverty, unemployment, violence and organized crime, and lack of access to basic services, such as health care and education. In order to tackle these determinants, and inspired by WHO's international Healthy Communities/Cities movement, the etwork of Healthy Communities of Rio de Janeiro was formed in 2004. The Network is coordinated by the Center for Health Promotion (CEDAPS) and now includes more than 100 community groups and organizations in the state of Rio de Janeiro.
View Article and Find Full Text PDFWe present neural network surrogates that provide extremely fast and accurate emulation of a large-scale circulation model for the coupled Columbia River, its estuary and near ocean regions. The circulation model has O(10(7)) degrees of freedom, is highly nonlinear and is driven by ocean, atmospheric and river influences at its boundaries. The surrogates provide accurate emulation of the full circulation code and run over 1000 times faster.
View Article and Find Full Text PDFTraditionally, food is associated with energetic and nutritious characteristics such as sources of carbohydrates, proteins and lipids. Recently, however, foods with bioactive substances such as isoflavones have received great attention. The objective of this study was therefore to evaluate the presence of the isoflavones daidzein, glycitein, genistein and their conjugated forms in grains and leaves of several leguminous plants utilized largely in Brazilian cuisine.
View Article and Find Full Text PDFHepatosplenic schistosomiasis was the first human disease in which the possibility of extensive long standing hepatic fibrosis being degraded and removed has been demonstrated. When such changes occurred, the main signs of portal hypertension (splenomegaly, esophageal varices) progressively disappeared, implying that a profound vascular remodeling was concomitantly occurring. Hepatic vascular alterations associated with advanced schistosomiasis have already been investigated.
View Article and Find Full Text PDFAmong the numerous ways of assessing regeneration after peripheral nerve lesions, the analysis of gait is one of the most important, because it shows the recovery of function, which is the ultimate goal of the repair machinery. The sciatic function index was introduced as a method to assess reinnervation after an experimental sciatic nerve lesion, and was adapted to the mouse model. The sciatic static index (SSI), is more simple and practical to perform, and is not so influenced by gait's velocity, but this method has not yet been adapted to the mouse model of sciatic lesion.
View Article and Find Full Text PDFAn extensive conformational study of the analgesic dipeptide kyotorphin (L-Tyr-L-Arg) at different pH values was performed using a constant-pH molecular dynamics method. This dipeptide showed a remarkable pH-dependent conformational variety. The protonation of the N-terminal amine was identified as a key element in the transition between the more extended and the more packed conformational states, as monitored by the dihedral angle defined by the atoms 1Cbeta-1Calpha-2Calpha-2Cbeta.
View Article and Find Full Text PDFAnaemia is a common finding in elderly patients particularly in those with chronic kidney disease. Effective correction of anaemia improves survival and quality of life. The association between anaemia and a poor nutritional status as well as the presence of inflammation has already been documented.
View Article and Find Full Text PDFClinics (Sao Paulo)
October 2006
Purpose: To evaluate 20 cases of nonmetastatic synovial sarcoma of the extremities regarding prognostic factors, and to propose a histologic grading system with prognostic significance.
Methods: The cases of 20 patients (14 females and 6 males) with nonmetastatic synovial sarcomas of the extremities treated between 1985 and 1998, were retrospectively evaluated regarding prognostic factors. A histologic grading system with prognostic significance is proposed.
Objectives: Anastomotic leak is a major complication after gastric bypass (GBP) surgery, and it usually necessitates reoperation and is associated with long-term recovery and death. We present our experience with the use of self-expandable metal stents (SEMS) to treat this complication.
Methods: Seventeen patients (14 males and 3 females, mean body mass index of 43.
Epithelial remodeling probably contributes to parenchymal deterioration in usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF), but understanding its mechanisms is still a challenge. The aim of our study was to examine apoptosis and the epithelial changes in the histologic pattern of UIP. After immunohistochemical staining we quantified the content of type I cells, type II cells, surfactant-A protein, bcl-2, and Fas-ligand (Fas-L) in control and alveolar collapse, fibroblastic foci, and honeycomb in UIP areas of 23 open lung biopsies.
View Article and Find Full Text PDFAnaemia and hypertension are common in patients with chronic renal insufficiency. The correction of anaemia with erythropoiesis stimulating agents (ESA) can improve survival and decrease the decline of renal function. Angiotensin converting-enzyme inhibitors (ACEI) and angiotensin II receptor blockers (AIIRA) can also slow the progression of renal failure, but the blockade of the renin-angiotensin system can worsen anaemia.
View Article and Find Full Text PDFObjective: Pathological fractures caused by metastases sharply decrease the quality of life and increase mortality rates for patients with malignant neoplasias. Orthopedic advances in osteosynthesis and endoprosthesis have been beneficial in the prevention and treatment of such fractures. The objective of our study was to determine which prognostic factors for pathologic fractures treated in our Service were significant.
View Article and Find Full Text PDFZinc centers play a key role as important structure determinants in a variety of proteins including ferredoxins (Fd). Here, we exploit the availability of two highly similar ferredoxin isoforms from the thermophile Sulfolobus metallicus, which differ in the residues involved in coordinating a His/Asp zinc site that ties together the protein core with its N-terminal extension, to investigate the effect of the absence of this site on ferredoxin folding. The conformational properties of the zinc-containing (FdA) and zinc-lacking (FdB) isoforms were investigated using visible absorption and tryptophan fluorescence emission.
View Article and Find Full Text PDFInt J Gynaecol Obstet
August 2006
Objective: The 5-year project in the province of Sofala was designed to improve access, quality and utilization of emergency obstetric care (EmOC) by strengthening rural hospitals and health centers and ultimately the health system's capacity to respond to emergencies more quickly and effectively.
Methods: Implementation consisted of attention to infrastructure, human resource development, transportation and communication systems, and management. Specific management aspects that were targeted for improvement included: supportive supervision, logistics for supplies, equipment and drugs, record keeping, monitoring and evaluation, and quality improvement techniques such as maternal death audits.
A united-atom model of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]) and 1-butyl-3-methylimidazolium nitrate ([BMIM][NO(3)]) is developed in the framework of the GROMOS96 43A1(1) force field. These two ionic liquids are parametrized, and their equilibrium properties in the 298-363 K temperature range are subjected to validation against known experimental properties, namely, density, self-diffusion, shear viscosity, and isothermal compressibility. The ionic radial/spatial distributions, pi interaction, gauche/trans populations of the butyl tail, and enthalpies of vaporization are also reported.
View Article and Find Full Text PDFPoisson-Boltzmann (PB) models are a fast and common tool for studying electrostatic processes in proteins, particularly their ionization equilibrium (protonation and/or reduction), often yielding quite good results when compared with more detailed models. Yet, they are conceptually very simple and necessarily approximate, their empirical character being most evident when it comes to the choice of the dielectric constant assigned to the protein region. The present study analyzes several factors affecting the ability of PB-based methods to model protein ionization equilibrium.
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