997 resultados para Readiness potential
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ABSTRACTSarcophagidae species are frequent and abundant in the decomposition process of corpses and, consequently, play an important role as a tool for the application of Forensic Entomology. Helicobia pilifera Lopes, 1939, Microcerella erythropyga (Lopes, 1936), Oxysarcodexia fringidea Curran & Walley, 1934 and Peckia (Peckia) pexata(Wulp, 1895) were recorded for the first time in a Forensic Entomology experiment in Rio de Janeiro, using domestic pig carcasses as substrate.
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Mutations of G protein-coupled receptors can increase their constitutive (agonist-independent) activity. Some of these mutations have been artificially introduced by site-directed mutagenesis, others occur spontaneously in human diseases. The analysis of the constitutively active G protein-coupled receptors has provided important informations about the molecular mechanisms underlying receptor activation and drug action.
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BACKGROUND: To be effective and selective, immunotherapy ideally targets specifically tumor cells and spares normal tissues. Identification of tumor specific antigens is a prerequisite to establish an effective immunotherapy. Still very little is known about the expression of tumor-related antigens in pancreatic neoplasms. Cancer Testis antigens (CT) are antigens shared by a variety of malignant tumors, but not by normal tissues with the exception of germ cells in testis. Restricted expression in neoplastic tissues and inherent immunogenic features make CT antigens ideal for use in immunotherapy. We analyzed the expression of a selected panel of nine CT antigens that have been proven to elicit an efficient immunogenic response in other malignancies. In addition we analyzed the expression of HERV-K-MEL, an immunogenic antigen of viral origin. METHODS: Pancreatic adenocarcinoma tumor samples (n=130) were obtained intraoperatively, control tissues (n=23) were collected from cadaveric donor and from patients with chronic pancreatitis. Tumor-associated antigen expression of MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, LAGE-1, NY-ESO-1, SCP-1, SSX-2, SSX-4 and HERV-K-MEL was assessed by PCR. Sequencing of PCR products were performed to assess the expression of SSX-4 in neoplastic and normal pancreatic tissues. RESULTS: Three of 10 tested antigens were expressed in over 10% of malignant pancreatic tissue samples. SSX-4 was found positive in 30% of cases, SCP-1 in 19% and HERV-K-MEL in 23% of cases. No expression of CT antigens was found in non-malignant pancreatic tissue with the exception of SSX-4 and and SSX-2. CONCLUSIONS: Fifty two percentage of the analyzed tissues expressed at least one CT antigen. The concomitant expression of SSX-4 in both malignant and non-malignant pancreatic tissue is a new finding which may raise concerns for immunotherapy. However, HERV-K-MEL is expressed with a relatively high prevalence and may be a candidate for specific immunotherapy in a large subgroup of pancreatic cancer patients. This study advocates the analysis of patients with regard to their immunogenic profile before the onset of antigen-specific immunotherapy.
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Rapport de synthèseApproche et objectifL'objectif de la recherche était de préciser les relations existant entre l'insuffisance rénale chronique, l'anémie et l'accident vasculaire cérébral parmi des patients hospitalisés au Centre Hospitalier Universitaire Vaudois (CHUV) pour un accident vasculaire cérébral (AVC). Les auteurs ont déterminé la prévalence de l'anémie et de l'insuffisance rénale chronique parmi ces patients et examiné s'ils sont des facteurs de risque indépendants de la mortalité suite à un AVC.L'insuffisance rénale chronique est associée à un risque élevé de développer un AVC. L'anémie est une complication et une conséquence fréquente qui découle de l'insuffisance rénale chronique et est également un facteur de risque pour les maladies cérébro- et cardiovasculaires.MéthodeLa présente étude de cohorte rétrospective se base sur le registre des AVC du CHUV et inclut tous les patients traités suite à un premier AVC au service de neurologie du CHUV entre les années 2000 et 2003.Les variables utilisées pour l'analyse sont les caractéristiques démographiques, l'insuffisance rénale chronique, le débit de filtration glomérulaire.(GFR), l'anémie et d'autres facteurs de risque d'AVC. Ils ont été récoltés au moyen du système informatique du laboratoire du CHUV, d'entretiens téléphoniques (patients ou proches) et du registre des AVC du CHUV.L'insuffisance rénale chronique a été calculée sur base de la ,,Kidney Disease Outcomes Quality Initiative (K/DOQI)-CKD Classification", laquelle est divisée en cinq stades. L'anémie a été définie par une hémoglobine de < 120g/L pour les femmes et < 130g/L pour les hommes.Les analyses statistiques réalisées sont des tests Chi-carré, des tests de Τ ainsi que des courbes de Kaplan-Meier et le modèle de régression de Cox.RésultatsParmi 890 patients adultes avec un AVC, le GFR moyen était de 64.3 ml/min/1.73 m2, 17% souffraient d'anémie et 10% sont décédés pendant la première année après la sortie de l'hôpital, suite à l'"AVC index". Parmi ceux-ci, 61% avaient une insuffisance rénale chronique de stade 3-5 et 39% de stade 1 ou 2 selon les critères de K/DOQI.D'autre part un taux d'hémoglobine élevé a pu être associé à un risque moins élevé de mortalité un an après la sortie de l'hôpital.Conclusion et perspectiveNous avons constaté que l'anémie ainsi que l'insuffisance rénale chronique sont fréquents parmi les patients souffrant d'un AVC et qu'ils sont des facteurs de risque d'un taux de mortalité élevé après un an. En conséquence, il pourrait être utile de traiter les patients souffrant d'anémie et d'insuffisance rénale dès que possible afin de diminuer les complications et comorbidités résultants de ces maladies.La perspective est de rendre les cliniciens attentif à l'importance de l'insuffisance rénale et de l'anémie parmi les patients ayants développé un AVC, ainsi que d'initier le traitement approprié afin de diminuer les complications, les comorbidités ainsi que les récidives d'un AVC. L'efficacité et l'économicité des interventions visant à améliorer le pronostic chez les patients présentant un AVC et souffrant d'une insuffisance rénale chronique et / ou d'une anémie doivent être évaluées par des études appropriées.
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During the last 2 years, several novel genes that encode glucose transporter-like proteins have been identified and characterized. Because of their sequence similarity with GLUT1, these genes appear to belong to the family of solute carriers 2A (SLC2A, protein symbol GLUT). Sequence comparisons of all 13 family members allow the definition of characteristic sugar/polyol transporter signatures: (1) the presence of 12 membrane-spanning helices, (2) seven conserved glycine residues in the helices, (3) several basic and acidic residues at the intracellular surface of the proteins, (4) two conserved tryptophan residues, and (5) two conserved tyrosine residues. On the basis of sequence similarities and characteristic elements, the extended GLUT family can be divided into three subfamilies, namely class I (the previously known glucose transporters GLUT1-4), class II (the previously known fructose transporter GLUT5, the GLUT7, GLUT9 and GLUT11), and class III (GLUT6, 8, 10, 12, and the myo-inositol transporter HMIT1). Functional characteristics have been reported for some of the novel GLUTs. Like GLUT1-4, they exhibit a tissue/cell-specific expression (GLUT6, leukocytes, brain; GLUT8, testis, blastocysts, brain, muscle, adipocytes; GLUT9, liver, kidney; GLUT10, liver, pancreas; GLUT11, heart, skeletal muscle). GLUT6 and GLUT8 appear to be regulated by sub-cellular redistribution, because they are targeted to intra-cellular compartments by dileucine motifs in a dynamin dependent manner. Sugar transport has been reported for GLUT6, 8, and 11; HMIT1 has been shown to be a H+/myo-inositol co-transporter. Thus, the members of the extended GLUT family exhibit a surprisingly diverse substrate specificity, and the definition of sequence elements determining this substrate specificity will require a full functional characterization of all members.
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Although the activation of the A(1)-subtype of the adenosine receptors (A(1)AR) is arrhythmogenic in the developing heart, little is known about the underlying downstream mechanisms. The aim of this study was to determine to what extent the transient receptor potential canonical (TRPC) channel 3, functioning as receptor-operated channel (ROC), contributes to the A(1)AR-induced conduction disturbances. Using embryonic atrial and ventricular myocytes obtained from 4-day-old chick embryos, we found that the specific activation of A(1)AR by CCPA induced sarcolemmal Ca(2+) entry. However, A(1)AR stimulation did not induce Ca(2+) release from the sarcoplasmic reticulum. Specific blockade of TRPC3 activity by Pyr3, by a dominant negative of TRPC3 construct, or inhibition of phospholipase Cs and PKCs strongly inhibited the A(1)AR-enhanced Ca(2+) entry. Ca(2+) entry through TRPC3 was activated by the 1,2-diacylglycerol (DAG) analog OAG via PKC-independent and -dependent mechanisms in atrial and ventricular myocytes, respectively. In parallel, inhibition of the atypical PKCζ by myristoylated PKCζ pseudosubstrate inhibitor significantly decreased the A(1)AR-enhanced Ca(2+) entry in both types of myocytes. Additionally, electrocardiography showed that inhibition of TRPC3 channel suppressed transient A(1)AR-induced conduction disturbances in the embryonic heart. Our data showing that A(1)AR activation subtly mediates a proarrhythmic Ca(2+) entry through TRPC3-encoded ROC by stimulating the phospholipase C/DAG/PKC cascade provide evidence for a novel pathway whereby Ca(2+) entry and cardiac function are altered. Thus, the A(1)AR-TRPC3 axis may represent a potential therapeutic target.
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This experiment was carried out under greenhouse conditions with soil pots during 210 days, to evaluate the effect of calcitic papermill lime-sludge application (at the rates 0, 773, 1.547, and 2.320 mg kg-1 or respective equivalents to control, 2, 4, and 6 t ha-1), on chemical composition of soil leachate and its effects on eucalypt growth and yield. Highest soil leachate pH, SO4, and Na concentrations occurred in the 4 and 6 t ha-1 treatments. Soil leachate nitrate concentrations decreased with increasing lime-sludge rate. Soil leachate phosphate remained low (below the detection limit) in all treatments until 120 days, while the concentration increased in the lime-sludge treatments at 210 days (last sampling) in about 600 mg L-1. Lime-sludge decreased leachate Mg concentration, but had no significant effect among rates. Soil leachate Ca, K, B, Cu, Fe, and Zn did not change significantly for any lime-sludge application rates. The maximum NO3, Ca, Mg, K, and Na concentrations in the soil leachate occurred at 60 days after lime-sludge application (leaching equivalent to 1 pore volume), but for pH and SO4, the maximum occurred at 210 days (leaching equivalent to 4 pore volumes). Lime-sludge application decreased the concentration of exchangeable Al in the soil. Plant diameter growth and dry matter yield were increased with increasing lime-sludge rate. Beneficial effects on mineral nutrition (P, K, Ca, B, and Zn) of eucalypts were also obtained by the application of 4 and 6 t ha-1 of lime-sludge.
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A new parameter is introduced: the lightning potential index (LPI), which is a measure of the potential for charge generation and separation that leads to lightning flashes in convective thunderstorms. The LPI is calculated within the charge separation region of clouds between 0 C and 20 C, where the noninductive mechanism involving collisions of ice and graupel particles in the presence of supercooled water is most effective. As shown in several case studies using the Weather Research and Forecasting (WRF) model with explicit microphysics, the LPI is highly correlated with observed lightning. It is suggested that the LPI may be a useful parameter for predicting lightning as well as a tool for improving weather forecasting of convective storms and heavy rainfall.
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Fatigue is defined as a sensation of exhaustion during or after usual activities. As much as one third of patients consulting a primary care physician report this complaint. After investigation, two-thirds of the patients have a somatic or psychiatric diagnosis. This review presents a seven-step approach to the patient who complains of fatigue.
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Multitrophic interactions mediate the ability of fungal pathogens to cause plant disease and the ability of bacterial antagonists to suppress disease. Antibiotic production by antagonists, which contributes to disease suppression, is known to be modulated by abiotic and host plant environmental conditions. Here, we demonstrate that a pathogen metabolite functions as a negative signal for bacterial antibiotic biosynthesis, which can determine the relative importance of biological control mechanisms available to antagonists and which may also influence fungus-bacterium ecological interactions. We found that production of the polyketide antibiotic 2,4-diacetylphloroglucinol (DAPG) was the primary biocontrol mechanism of Pseudomonas fluorescens strain Q2-87 against Fusarium oxysporum f. sp. radicis-lycopersici on the tomato as determined with mutational analysis. In contrast, DAPG was not important for the less-disease-suppressive strain CHA0. This was explained by differential sensitivity of the bacteria to fusaric acid, a pathogen phyto- and mycotoxin that specifically blocked DAPG biosynthesis in strain CHA0 but not in strain Q2-87. In CHA0, hydrogen cyanide, a biocide not repressed by fusaric acid, played a more important role in disease suppression.