989 resultados para Early Neuron Differentiation


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The results of this study challenge the widely held view that growth hormone (GH) acts only during the postnatal period. RNA phenotyping shows transcripts for the GH receptor and GH-binding protein in mouse preimplantation embryos of all stages from fertilized eggs (day 1) to blastocysts (day 4). An antibody specific to the cytoplasmic region of the GH receptor revealed receptor protein expression, first in two-cell embryos, the stage of activation of the embryonic genome (day 2), and in all subsequent stages, In cleavage-stage embryos this immunoreactivity was localized mainly to the nucleus, but clear evidence of membrane labeling was apparent in blastocysts. GH receptor immunoreactivity was also observed in cumulus cells associated with unfertilized oocytes but not in the unfertilized oocytes. The blastocyst receptor was demonstrated to be functional, exhibiting the classic bell-shaped dose-response curves for GH stimulation of both 3-O-methyl glucose transport and protein synthesis. Maximal stimulation of 40-50% was seen for both responses at less than 1 ng/ml recombinant GH, suggesting a role for maternal GK. However mRNA transcripts for GH were also detected from the morula stage (day 3) by using reverse transcription-PCR, and GH immunoreactivity was seen in blastocysts. These observations raise the possibility of a paracrine/autocrine GH loop regulating embryonic development in its earliest stages.

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Incomplete revascularization is associated with worse long-term outcomes. Autologous bone marrow cells (BMC) have recently been tested in patients with severe coronary artery disease. We tested the hypothesis that intramyocardial injection of autologous BMC increases myocardial perfusion in patients undergoing incomplete coronary artery bypass grafting (CABG). Twenty-one patients (19 men), 59 +/- 7 years old, with limiting angina and multivessel coronary artery disease (CAD), not amenable to complete CABG were enrolled. BMC were obtained prior to surgery, and the lymphomonocytic fraction separated by density gradient centrifugation. During surgery, 5 mL containing 2.1 +/- 1.3 x 10(8) BMC (CD34+ = 0.8 +/- 0.3%) were injected in the ischemic non-revascularized myocardium. Myocardial perfusion was assessed by magnetic resonance imaging (MRI) at baseline and 1 month after surgery. The increase in myocardial perfusion was compared between patients with < 50% (group A, n = 11) with that of patients with > 50% (group B, n = 10) of target vessels (stenosis a parts per thousand yenaEuro parts per thousand 70%) successfully bypassed. Injected myocardial segments included the inferior (n = 12), anterior (n = 7), and lateral (n = 2) walls. The number of treated vessels (2.3 +/- 0.8) was significantly smaller than the number of target vessels (4.2 +/- 1.0; P < 0.0001). One month after surgery, cardiac MRI showed a similar reduction (%) in the ischemic score of patients in group A (72.5 +/- 3.2), compared to patients in group B (78.1 +/- 3.2; P = .80). Intramyocardial injection of autologous BMC may help increase myocardial perfusion in patients undergoing incomplete CABG, even in those with fewer target vessels successfully treated. This strategy may be an adjunctive therapy for patients suffering from a more advanced (diffuse) CAD not amenable for complete direct revascularization.

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Idiopathic pulmonary fibrosis is a distinctive, usually fatal, type of chronic fibrosing interstitial pneumonia of unknown cause that increases in prevalence with advanced age, characterized by failure of alveolar re-epithelization and progressive scar formation. Recently, limitation of the replicative capacity of tissues determined by telomerase/apoptosis balance has been implicated in pathogenesis of age-related diseases. In this study, we validated the importance of the expression of type 2 alveolar epithelial cells telomerase protein and studied the relationships between telomerase and apoptosis in early remodeling of usual interstitial pneumonia. We determined type 2 alveolar epithelial cells density, telomerase expression, and apoptosis in surgical lung biopsies from 24 patients with usual interstitial pneumonia, and in normal lung tissues from 18 subjects. We used immunohistochemistry, deoxynucleotidyl transferase method of end labeling, electron microscopy, and histomorphometry to evaluate the amount of type 2 alveolar epithelial cells staining for surfactant-A, telomerase, and in situ detection of apoptotic cells. Unaffected areas of usual interstitial pneumonia and normal lung tissue had similar densities of type 2 alveolar epithelial cells, but a significant minor subpopulation of type 2 alveolar epithelial cells was telomerase positive and a large population was telomerase negative. A significant inverse association was found between low type 2, alveolar. epithelial cell telomerase expression and high apoptosis in unaffected areas of usual interstitial pneumonia. Although type 2 alveolar epithelial cell telomerase expression was higher than apoptosis in NLT group, no significant association was found between them. Electron microscopy confirmed epithelial apoptosis, alveolar collapse, and initial fibroplasia. We conclude that abnormal type 2 alveolar epithelial cells telomerase/apoptosis balance may reduce alveolar epithelial regenerative capacity, thus contributing to the early remodeling response in usual interstitial pneumonia. (C) 2010 Elsevier Inc. All rights reserved.

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Systemic injection of kainic acid (KA) results in characteristic behaviors and programmed cell death in some regions of the rat brain. We used KA followed by recovery at 4 degrees C to restrict damage to limbic structures and compared patterns of immediate early gene (IEG) expression and associated DNA binding activity in these damaged areas with that in spared brain regions. Male Wistar rats were injected with BA (12 mg/kg, ip) and kept at 4 degrees C for 5 h. This treatment reduced the severity of behaviors and restricted damage (observed by Nissl staining) to the CA1 and CA3 regions of the hippocampus and an area including the entorhinal cortex. DNA laddering, characteristic of apoptosis, was first evident in the hippocampus and the entorhinal cortex 18 and 22 h after RA, respectively. The pattern of IEG mRNA induction fell into three classes: IEGs that were induced in both damaged and spared areas (c-fos, fos B, jun B, and egr-1), IEGs that were induced specifically in the damaged areas (fra-2 and c-jun), and an IEG that was significantly induced by saline injection and/or the cold treatment (jun D). The pattern of immunoreactivity closely followed that of mRNA expression. Binding to the AP-1 and EGR DNA consensus sequences increased in all three regions studied. This study describes a unique modification of the animal model of ICA-induced neurotoxicity which may prove a useful tool for dissecting the molecular cascade that ultimately results in programmed cell death. (C) 1997 Academic Press.

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Background Treatment with adjuvant trastuzumab for 1 year improves disease-free survival and overall survival in patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. We aimed to assess disease-free survival and overall survival after a median follow-up of 4 years for patients enrolled on the Herceptin Adjuvant (HERA) trial. Methods The HERA trial is an international, multicentre, randomised, open-label, phase 3 trial comparing treatment with trastuzumab for 1 and 2 years with observation after standard neoadjuvant, adjuvant chemotherapy, or both in patients with HER2-positive early breast cancer. The primary endpoint was disease-free survival. After a positive first interim analysis at a median follow-up of 1 year for the comparison of treatment with trastuzumab for 1 year with observation, event-free patients in the observation group were allowed to cross over to receive trastuzumab. We report trial outcomes for the 1-year trastuzumab and observation groups at a median follow-up of 48.4 months (IQR 42.0-56.5) and assess the effect of the extensive crossover to trastuzumab. Our analysis was by intention-to-treat. The HERA trial is registered with the European Clinical Trials Database, number 2005-002385-11. Findings The HERA trial population comprised 1698 patients randomly assigned to the observation group and 1703 to the 1-year trastuzumab group. Intention-to-treat analysis of disease-free survival showed a significant benefit in favour of patients in the 1-year trastuzumab group (4-year disease-free survival 78.6%) compared with the observation group (4-year disease-free survival 72.2%; hazard ratio [HR] 0.76; 95% CI 0.66-0.87; p<0.0001). Intention-to-treat analysis of overall survival showed no significant difference in the risk of death (4-year overall survival 89.3% vs 87.7%, respectively; HR 0.85; 95% CI 0.70-1.04; p=0.11). Overall, 885 patients (52%) of the 1698 patients in the observation group crossed over to receive trastuzumab, and began treatment at median 22.8 months (range 4.5-52.7) from randomisation. In a non-randomised comparison, patients in the selective-crossover cohort had fewer disease-free survival events than patients remaining in the observation group (adjusted HR 0.68; 95% CI 0.51-0.90; p=0.0077). Higher incidences of grade 3-4 and fatal adverse events were noted on 1-year trastuzumab than in the observation group. The most common grade 3 or 4 adverse events, each in less than 1% of patients, were congestive cardiac failure, hypertension, arthralgia, back pain, central-line infection, hot flush, headache, and diarrhoea. Interpretation Treatment with adjuvant trastuzumab for 1 year after chemotherapy is associated with significant clinical benefit at 4-year median follow-up. The substantial selective crossover of patients in the observation group to trastuzumab was associated with improved outcomes for this cohort.

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Galectins are beta-galactoside-binding lectins involved in several biological processes and galectin-3 (Gal-3) is related to modulation of immune and inflammatory responses. This study aimed to evaluate the role of Gal-3 in the life span and biological functions of murine neutrophils during in vitro infection by virulent Toxoplasma gondii RH strain. Inflammatory peritoneal neutrophils (N phi) from C57BL/6 wildtype (WT) and Gal-3 knockout (KO) mice were cultured in the presence or absence of parasites and analyzed for phosphatidylserine (PS) exposure and cell death using Annexin-V and propidium iodide staining, and cell viability by MU assay. Cell toxicities determined by lactate dehydrogenase (LDH), degranulation by lysozyme release, and cytokine production were measured in NO culture supernatants. Phorbol myristate acetate (PMA)- or zymosan-dependent reactive oxygen species (ROS) were measured in N phi cultures. Our results demonstrated that Gal-3 is involved in the increase of the viable Not. number and the decrease of PS exposure and cell death following T. gondii infection. We also observed that Gal-3 downmodulates gondii-induced N phi toxicity as well as N phi degranulation regardless of infection. Furthermore, Gal-3 expression by N phi was associated with increased levels of IL-10 in the beginning and decreased levels of TNF-alpha later on, regardless of parasite infection, as well as with decreased levels of IL-6 and increased IL-12 levels, following early parasite infection. Our results also showed that Gal-3 suppresses PMA- but not zymosan-induced ROS generation in N phi following T. gondii infection. In conclusion, Gal-3 plays an important modulatory role by interfering in N phi life span and activation during early T gondii infection. (C) 2009 Elsevier GmbH. All rights reserved.

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To date, several activating mutations have been discovered in the common signal-transducing subunit (h beta c) of the receptors for human granulocyte-macrophage colony-stimulating factor, interleukin-3, and interleukin-5. Two of these, Fl Delta and 1374N, result in a 37 amino acid duplication and a single amino acid substitution in the extracellular domain of h beta c, respectively. A third, V449E, results in a single amino acid substitution in the transmembrane domain, Previous studies comparing the activity of these mutants in different hematopoietic cell lines imply that the transmembrane and extracellular mutations act by different mechanisms and suggest the requirement for cell type-specific molecules in signalling. To characterize the ability of these mutant hpc subunits to mediate growth and differentiation of primary cells and hence investigate their oncogenic potential, we have expressed all three mutants in primary murine hematopoietic cells using retroviral transduction. It is shown that, whereas expression of either extracellular hpc mutant confers factor-independent proliferation and differentiation on cells of the neutrophil and monocyte lineages only, expression of the transmembrane mutant does so on these lineages as well as the eosinophil, basophil, megakaryocyte, and erythroid lineages, Factor-independent myeloid precursors expressing the transmembrane mutant display extended proliferation in liquid culture and in some cases yielded immortalized cell lines. (C) 1997 by The American Society of Hematology.

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Malignant melanoma is one of the most lethal cancers. Nowadays, several anti-melanoma therapies have been employed. However, the poor prognosis and/or the increased toxicity of those treatments clearly demonstrate the requirement of searching for new drugs or novel combined chemotherapeutic protocols, contemplating both effectiveness and low toxicity. Guanosine (Guo) has been used in combination with acriflavina to potentiate the latter`s antitumor activity, through still unknown mechanisms. Here, we show that Guo induces B16F10 melanoma cell differentiation, attested by growth arrest, dendrite-like outgrowth and increased melanogenesis, and also reduced motility. A sustained ERK 1/2 phosphorylation was observed after Guo treatment and ERK inhibition led to blockage of dendritogenesis. Intracellular cyclic AMP was not involved in ERK activation, since its levels remained unchanged. Protein kinase C (PKC), in contrast to phospholipase C (PLC), inhibition completely prevented ERK activation. While the classical melanoma differentiation agent forskolin activates cAMP-PKA-Raf-MEK-ERK pathway in B16F10 cells, here we suggest that a cAMP-independent, PKC-ERK axis is involved in Guo-induced B16F10 differentiation. Altogether, our results show that Guo acts as a differentiating agent, with cytostatic rather than cytotoxic properties, leading to a decreased melanoma malignancy. Thus, we propose that Guo may be envisaged in combination with lower doses of conventional anti-melanoma drugs, in an attempt to prevent or diminish their adverse effects. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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SUBPOPULATIONS of olfactory receptor neurons, which are dispersed throughout the olfactory neuroepithelium, express specific cell surface carbohydrates and project to discrete regions of the olfactory bulb. Cell surface carbohydrates such as N-acetyl-lactosamine have been postulated to mediate sorting and selective fasciculation of discrete axon subpopulations during development of the olfactory pathway. Substrate-bound N-acetyl-lactosamine promotes neurite outgrowth by both clonal olfactory receptor neuron cell lines and olfactory receptor neurons in vitro, indicating that cell surface carbohydrates may be ligands for receptor-mediated stimulation of axon growth in vivo. In the present study, the role of transmembrane signaling in N-acetyl-lactosamine-stimulated neurite outgrowth was examined in the clonal olfactory neuron cell line 4.4.2. Substrate-bound N-acetyl-lactosamine stimulated neurite outgrowth which was specifically inhibited by antagonists to N- and L-type calcium channels and to tyrosine kinase phosphorylation. These results indicate that N-acetyl-lactosamine can evoke transmembrane receptor-mediated responses capable of influencing neurite outgrowth.

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Background/Aims: Late efficacy of medical treatment of chronic anal fissure remains controversial due to high recurrence. This study aimed at analyzing safety and efficacy of topical diltiazem and bethanechol regarding healing and symptoms relief, safety, recurrence, and need for surgery. Methodology: This was a single-center non-randomized trial. Outcomes of 30 patients with chronic anal fissure treated with 2% diltiazem were compared to 30 patients treated with 0.1% bethanechol, both for eight weeks. Patients were assessed after seven days and eight weeks. Results: In diltiazem group, after seven days, 31% were symptomatic; after bethanechol, 71% (p=0.06). After seven days, fissure healing occurred in 19% after diltiazem and in 11% after bethanechol. After eight weeks, in both groups, 64% were asymptomatic; after diltiazem, 53% healed; after bethanechol, 50% (p=0.80). Success was the same for both groups: 63.3%. Groups were similar regarding complications. After diltiazem, 9 (30%) patients were operated on; and 11 (36.7%) after bethanechol (p=0.60). Recurrence occurred in 4 (13.3%) patients in both groups. Median time to recurrence after diltiazem was 15 (10-24) months and 7.5 (2-15) after bethanechol - p=0.15. Conclusions: Both treatments are safe and effective. Diltiazem may be associated to earlier relief and more sustained response.

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BACKGROUND: Early gastric cancer (EGC) is defined as adenocarcinoma limited to the mucosa or submucosa regardless of lymph node involvement. Local EGC recurrence rates have been described ill Lip to 6% of cases. OBJECTIVES: To evaluate predictive factors for incomplete resection and local recurrence of EGC treated by endoscopic mucosal resection (EMR) that was followed up for at least one year. METHODS: From June 1994 to December 2005, 46 patients with EGC underwent EMR. Possible predictive factors for incomplete endoscopic resection and local recurrence were identified by medical chart analysis. Demographic, endoscopic and histopathological data were retrospectively evaluated. EMR was considered complete or incomplete. Patients from the complete resection group were divided into subgroups (with and without local EGC recurrence). RESULTS: Complete resection was possible in 36 cases (76.6%). Predictive factors for incomplete resection were turnout location (P=0.035), histological type (P=0.021), lesion size (P=0.022) and number of resected fragments (P=0.013). On multivariate analysis, undifferentiated histological type (OR 0.8; 95% Cl 0.036 to 0.897) and number of resected fragments (OR 7.34; 95% Cl 1.266 to 42.629) were independent predictive factors for incomplete resection. In the complete resection group, a larger lesion size was associated with a higher the number of resected fragments (P=0.018). Local recurrence occurred in nine cases (25%). Use of the cap technique was the only predictive factor for local recurrence in five of seven cases (71.4%) (P=0.006). CONCLUSIONS: A larger lesion size was associated with a higher number of resected fragments. Undifferentiated adenocarcinoma and piecemeal resection were predictive factors for incomplete resection. Technique type was a predictive factor for local EGC recurrence.

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Primary murine fetal hemopoietic cells were transformed with a fusion protein consisting of the ligand-binding domain of the estrogen receptor and a carboxyl-terminally truncated c-Myb protein (ERMYB), The ERMYB-transformed hemopoietic cells exhibit an immature myeloid phenotype when grown in the presence of beta-estradiol. Upon removal of beta-estradiol, the ERMYB cells display increased adherence, decreased clonogenicity and differentiate to cells exhibiting granulocyte or macrophage morphology, The expression of the c-myc, c-kit, cdc2 and bcl-2 genes, which are putatively regulated by Myb, was investigated in ERMYB cells grown in the presence or absence of beta-estradiol. Neither c-myc nor cdc2 expression was down-regulated after removal of beta-estradiol demonstrating that differentiation is not a consequence of decreased transactivation of these genes by ERMYB. While bcl-2 expression was reduced by 50% in ERMYB cells grown in the absence of beta-estradiol, there was no increase in DNA laddering, suggesting that Myb was not protecting ERMYB cells from apoptosis, In contrast, a substantial (200-fold) decrease in c-kit mRNA level was observed following differentiation of ERMYB cells, and c-kit mRNA could be partially re-induced by the re-addition of beta-estradiol. Furthermore, a reporter construct containing the c-kit promoter was activated when cotransfected with a Myb expression vector, providing further evidence of a role for Myb in the regulation of c-kit.

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Rats exposed to a relatively high dose (7.5 g/kg body weight) of alcohol on either the fifth or tenth postnatal day of age have been reported to have long-lasting deficits in spatial learning ability as tested on the Morris water maze task. The question arises concerning the level of alcohol required to achieve this effect. Wistar rats were exposed to either 2, 4 or 6 g/kg body weight of ethanol administered as a 10% solution. This ethanol was given over an 8-h period on the fifth postnatal day of age by means of an intragastric cannula. Gastrostomy controls received a 5% sucrose solution substituted isocalorically for the ethanol. Another set of pups raised by their mother were used as suckle controls. All surgical procedures were carried out under halothane vapour anaesthesia. After the artificial feeding regimes all pups were returned to lactating dams and weaned at 21 days of age. The spatial learning ability of these rats was tested in the Morris water maze when they were between 61-64 days of age. This task requires the rats to swim in a pool containing water made opaque and locate and climb onto a submerged platform. The time taken to accomplish this is known as the escape latency. Each rat was subjected to 24 trials over 3 days of the test period. Statistical analysis of the escape latency data revealed that the rats given 6 g/kg body weight of ethanol had significant deficits in their spatial learning ability compared with their control groups. However, there was no significant difference in spatial learning ability for the rats given either 2 or 4 g/kg body weight of ethanol compared with their respective gastrostomy or suckle control animals. We concluded that ethanol exposure greater than 4 g/kg over an 8-h period to 5-day-old rats is required for them to develop long-term deficits in spatial learning behaviour. (C) 1998 Elsevier Science Inc.

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The objective of this study was to find very early viral kinetic markers to predict nonresponse to hepatitis C virus (HCV) therapy in a group of human immunodeficiency virus (HIV)/HCV-coinfected patients. Twenty-six patients (15 HCV genotype-1 and 11 genotype-3) were treated with a 48-week regimen of peginterferon-alfa-2a (PEG-IFN) (180 mu g/week) and weight-based ribavirin (11 mg/kg/day). Samples were collected at baseline; 4, 8, 12, 18, 24, 30, 36 and 42 h; days 2, 3, 4, 7, 8, 15, 22, 29, 43 and 57 then weekly and monthly. Five patients discontinued treatment. Seven patients (27%) achieved a sustained virological response (SVR). Nadir HCV RNA levels were observed 1.6 +/- 0.3 days after initiation of therapy, followed by a 0.3- to 12.9-fold viral rebound until the administration of the second dose of PEG-IFN, which were not associated with SVR or HCV genotype. A viral decline < 1.19 log for genotype-1 and < 0.97 log for genotype-3, 2 days after starting therapy, had a negative predictive value (NPV) of 100% for SVR. The day 2 virological response had a similar positive predictive value for SVR as a rapid virological response at week 4. In addition, a second-phase viral decline slope (i.e., measured from day 2 to 29) < 0.3 log/week had a NPV = 100% for SVR. We conclude that first-phase viral decline at day 2 and second-phase viral decline slope (< 0.3 log/week) are excellent predictors of nonresponse. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of nonresponse in patients with HCV and HIV.