Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Int J Environ Health Res ; : 1-12, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38817088

RESUMO

Parents´ perceptions can influence their children´s mode of commuting to school. In this sense, the purposes of this study were to compare parental barriers towards active commuting to school (ACS) between Ecuadorian and Spanish children, and to analyze the associations between those barriers and the children's mode of commuting. Descriptive and comparative analyses were performed using Chi-square and T-student test. Associations were analyzed by several logistic regression models. Results showed that road safety is the main barrier for ACS, and that all the barriers are perceived as higher by Ecuadorian parents (p<0.001). It was also found that Ecuadorian children were less likely to be active when parents perceive greater total barriers (OR=0.15, CI=0.06, 0.40). Public policies should focus on reducing the parental barriers in order to increase ACS, specifically those related to road safety.

2.
Gastroenterol Hepatol ; 47(3): 253-261, 2024 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-37330213

RESUMO

BACKGROUND: The frequency and patterns of use of scores for the assessment of endoscopic activity in inflammatory bowel disease patients are not known. AIM: To describe the prevalence of adequate use of endoscopic scores in IBD patients who underwent colonoscopy in a real-life setting. MATERIALS AND METHODS: A multicenter observational study comprising six community hospitals in Argentina was undertaken. Patients with a diagnosis of Crohn's disease or ulcerative colitis who underwent colonoscopy for endoscopic activity assessment between 2018 and 2022 were included. Colonoscopy reports of included subjects were manually reviewed to determine the proportion of colonoscopies that included an endoscopic score report. We determined the proportion of colonoscopy reports that included all of the IBD colonoscopy report quality elements proposed by BRIDGe group. Endoscopist's specialty, years of experience as well as expertise in IBD were assessed. RESULTS: A total of 1556 patients were included for analysis (31.94% patients with Crohn's disease). Mean age was 45.94±15.46. Endoscopic score reporting was found in 58.41% of colonoscopies. Most frequently used scores were Mayo endoscopic score (90.56%) and SES-CD (56.03%) for ulcerative colitis and Crohn's disease, respectively. In addition, 79.11% of endoscopic reports failed to comply with all recommendations on endoscopic reporting for inflammatory bowel disease. CONCLUSIONS: A significant proportion of endoscopic reports of inflammatory bowel disease patients do not include the description of an endoscopic score to assess mucosal inflammatory activity in a real-world setting. This is also associated with a lack of compliance in recommended criteria for proper endoscopic reporting.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Adulto , Pessoa de Meia-Idade , Doença de Crohn/diagnóstico , Argentina/epidemiologia , Colonoscopia
3.
Rev Med Chil ; 145(12): 1551-1558, 2017 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-29652951

RESUMO

Background Campylobacter jejuni is one of the main causal agents of food borne diseases. Infections with this pathogen are mainly caused by chicken meat consumption. Aim To characterize antibiotic resistance and virulence factors in C. jejuni strains obtained from chicken meat and poultry feces in Central Chile. Material and Methods The presence of C. jejuni in 30 meat and 40 feces samples from poultry was studied. From these samples, we obtained 40 strains which were characterized at the molecular level for the presence of 16 genes involved in virulence using PCR. In parallel, antibiotic resistance for ciprofloxacin, nalidixic acid, tetracycline, erythromycin, azithromycin, chloramphenicol y ampicillin was analyzed. Results Twenty and 63% of feces and chicken meat samples were positive for C. jejuni, respectively. Moreover, a high percentage of strains showed antibiotic resistance, where 27% of strains were resistant to all tested antibiotics, except for azithromycin. Finally, 10% of the strains coming from feces contained 14 out of 16 virulence genes evaluated. Only 23% of the strains did not contain any of these genes. Conclusions A high percentage of feces and chicken meat samples are contaminated with C. jejuni. Moreover, these strains show a high genetic and phenotypic diversity represented by their antibiotic resistance profiles and the presence of virulence factors.


Assuntos
Antibacterianos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/patogenicidade , Fezes/microbiologia , Produtos Avícolas/microbiologia , Animais , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Galinhas , DNA Bacteriano , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Valores de Referência , Fatores de Virulência
4.
Semin Thromb Hemost ; 39(3): 283-90, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23457048

RESUMO

Mixing tests are a relatively simple procedure used in the hemostasis laboratory as a first-line investigation into the cause of an abnormal screening test, typically a prolonged activated partial thromboplastin time and/or a prolonged prothrombin time. The mixing test involves combining the test plasma with normal plasma, then repeating the screening test on the mixture to assess whether the clotting time becomes normal or remains prolonged. The primary purpose of a mixing test is to guide further investigations. When mixing test results "normalize," this suggests the test plasma is deficient in clotting factor(s) and thus specific factor assays can be performed to determine which are reduced. When the mixing test result does not "normalize," this suggests the presence of an inhibitor or other type of interference (e.g., the presence of an anticoagulant such as high-dose heparinoids), and so the laboratory needs to determine if this is a lupus anticoagulant or a specific coagulation factor inhibitor, or another type of inhibitor. Because these follow-up investigations are more costly and time-consuming than the basic screening tests, the appropriate performance and interpretation of mixing tests is advantageous for the laboratory. Moreover, the correct laboratory approach is also clinically relevant, as patient management is ultimately affected, and an incorrect interpretation may lead to inappropriate therapies being established. Components of a mixing test that can influence result interpretation include the sensitivity of the used screening reagents to various factor deficiencies and inhibitors, the source or composition of the normal plasma, and the setting of cutoffs for the formula used in expressing mixing test results. Numerous and differing criteria for mixing test interpretation have been suggested historically, which can lead to confusion as to which approach is the most appropriate. The use of differing criteria will also lead to differing interpretations regarding "normalization." For this pivotal reason, standardized mixing test procedures and a consistent set of validated interpretive criteria represent the most favorable approach to maximizing the utility of a mixing test, and ensure the most accurate diagnosis for investigated patients.


Assuntos
Transtornos da Coagulação Sanguínea/sangue , Fatores de Coagulação Sanguínea/análise , Tempo de Tromboplastina Parcial/métodos , Tempo de Protrombina/métodos , Transtornos da Coagulação Sanguínea/diagnóstico , Humanos , Tempo de Tromboplastina Parcial/instrumentação , Tempo de Protrombina/instrumentação
5.
EMBO Mol Med ; 15(11): e15984, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37792911

RESUMO

Cell signaling is central to neuronal activity and its dysregulation may lead to neurodegeneration and cognitive decline. Here, we show that selective genetic potentiation of neuronal ERK signaling prevents cell death in vitro and in vivo in the mouse brain, while attenuation of ERK signaling does the opposite. This neuroprotective effect mediated by an enhanced nuclear ERK activity can also be induced by the novel cell penetrating peptide RB5. In vitro administration of RB5 disrupts the preferential interaction of ERK1 MAP kinase with importinα1/KPNA2 over ERK2, facilitates ERK1/2 nuclear translocation, and enhances global ERK activity. Importantly, RB5 treatment in vivo promotes neuroprotection in mouse models of Huntington's (HD), Alzheimer's (AD), and Parkinson's (PD) disease, and enhances ERK signaling in a human cellular model of HD. Additionally, RB5-mediated potentiation of ERK nuclear signaling facilitates synaptic plasticity, enhances cognition in healthy rodents, and rescues cognitive impairments in AD and HD models. The reported molecular mechanism shared across multiple neurodegenerative disorders reveals a potential new therapeutic target approach based on the modulation of KPNA2-ERK1/2 interactions.


Assuntos
Sistema de Sinalização das MAP Quinases , Neuroproteção , Animais , Humanos , Camundongos , alfa Carioferinas/farmacologia , Cognição , Fosforilação , Transdução de Sinais
6.
Semin Thromb Hemost ; 38(4): 375-84, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22573409

RESUMO

The main laboratory characteristic of lupus anticoagulants (LA) is their ability to prolong phospholipid-dependent clotting time in vitro. The laboratory demonstration of LA requires a systematic approach combined with an awareness of the many variables that can affect test results. The ideal testing procedures are those sensitive enough to detect weak LA and specific enough so as not to produce incorrect conclusions. International guidelines have been published to assist laboratories in applying correct testing processes. The most recently published guidelines from the International Society on Thrombosis and Haemostasis update the criteria for detecting the presence of LA that were presented in the 1995 guidelines. Some of the specific recommendations relate to the key areas of setting cut-off levels for screening, mixing, and confirmatory procedures. The more challenging aspects of testing for LA include maintaining sensitivity and specificity of the assays, especially in the presence of anticoagulant therapy.


Assuntos
Inibidor de Coagulação do Lúpus/análise , Testes de Coagulação Sanguínea/métodos , Feminino , Humanos , Inibidor de Coagulação do Lúpus/sangue , Gravidez
7.
J Biol Chem ; 285(30): 23444-56, 2010 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-20498378

RESUMO

A truncated isoform of C/EBPbeta, C/EBPbeta-LIP, is required for liver proliferation. This isoform is expressed at high levels in proliferating liver and in liver tumors. However, high levels of C/EBPbeta-LIP are also observed in non-proliferating livers during acute phase response (APR). In this paper we present mechanisms by which liver regulates activities of C/EBPbeta-LIP. We found that calmodulin (CaM) inhibits the ability of C/EBPbeta-LIP to promote liver proliferation during APR through direct interactions. This activity of CaM is under negative control of Ca(2+), which is reduced in nuclei of livers with APR, whereas it is increased in nuclei of proliferating livers. A mutant CaM, which does not interact with C/EBPbeta-LIP, also fails to inhibit the growth promotion activity of C/EBPbeta-LIP. Down-regulation of CaM in livers of LPS-treated mice causes liver proliferation via activation of C/EBPbeta-LIP. Overexpression of C/EBPbeta-LIP above levels of CaM also initiates liver proliferation in LPS-treated mice. In addition, CaM regulates transcriptional activity of another isoform of C/EBPbeta, C/EBPbeta-LAP, and might control liver biology through the regulation of both isoforms of C/EBPbeta. In searching for molecular mechanisms by which C/EBPbeta-LIP promotes cell proliferation, we found that C/EBPbeta-LIP releases E2F.Rb-dependent repression of cell cycle genes by a disruption of E2F1.Rb complexes and by a direct interaction with E2F-dependent promoters. CaM inhibits these growth promotion activities of C/EBPbeta-LIP and, therefore, supports liver quiescence. Thus, our findings discover a new pathway of the regulation of liver proliferation that involves calcium-CaM signaling.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Calmodulina/metabolismo , Fígado/citologia , Fígado/metabolismo , Reação de Fase Aguda/metabolismo , Reação de Fase Aguda/patologia , Animais , Cálcio/metabolismo , Proteínas de Ciclo Celular/genética , Linhagem Celular , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Fatores de Transcrição E2F/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Fígado/efeitos dos fármacos , Camundongos , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteína do Retinoblastoma/metabolismo , Transativadores/genética
8.
Artigo em Inglês | MEDLINE | ID: mdl-33925680

RESUMO

A door-to-door survey was organised in Cuenca, Ecuador, to determine the prevalence of COVID-19 infection and adherence of the population to COVID-19 preventive measures. A total of 2457 persons participated in the study; 584 (23.7%) reported having experienced at least one flu-like symptom since the onset of the pandemic. The maximum SARS-CoV-2 seroprevalence in Cuenca was 13.2% (CI: 12-14.6%) (IgM or IgG positive). Considering PCR confirmed infections, the prevalence was 11% (CI: 10-12.4%). There was no significant difference in seroprevalence between rural and urban areas. Participants aged 35-49 years old, living with a COVID-19 positive person, at least six people in a household, physical contact with someone outside the household, a contact with a person outside the home with flu-like symptoms, using public transport, and not having enough resources for living, significantly increased the odds for SARS-CoV-2 seropositivity. Overall, there was good adherence to COVID-19 preventive measures. Having known someone who tested positive for COVID-19, having a primary or secondary level of education, and having enough resources for living, significantly increased the odds for higher adherence. In conclusion, despite good overall adherence of the population of Cuenca with COVID-19 preventive measures, our study suggests high ongoing COVID-19 transmission in Cuenca, particularly in certain parishes. Prevention should not only focus on behavioural change, but on intensified testing strategies in demographical risk groups.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , Estudos Transversais , Equador/epidemiologia , Humanos , Pessoa de Meia-Idade , Estudos Soroepidemiológicos
9.
Stem Cell Reports ; 13(5): 832-846, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31587993

RESUMO

Neuroferritinopathy (NF) is a movement disorder caused by alterations in the L-ferritin gene that generate cytosolic free iron. NF is a unique pathophysiological model for determining the direct consequences of cell iron dysregulation. We established lines of induced pluripotent stem cells from fibroblasts from two NF patients and one isogenic control obtained by CRISPR/Cas9 technology. NF fibroblasts, neural progenitors, and neurons exhibited the presence of increased cytosolic iron, which was also detectable as: ferritin aggregates, alterations in the iron parameters, oxidative damage, and the onset of a senescence phenotype, particularly severe in the neurons. In this spontaneous senescence model, NF cells had impaired survival and died by ferroptosis. Thus, non-ferritin-bound iron is sufficient per se to cause both cell senescence and ferroptotic cell death in human fibroblasts and neurons. These results provide strong evidence supporting the primary role of iron in neuronal aging and degeneration.


Assuntos
Ferroptose , Distúrbios do Metabolismo do Ferro/patologia , Ferro/metabolismo , Distrofias Neuroaxonais/patologia , Neurônios/patologia , Células Cultivadas , Senescência Celular , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Distúrbios do Metabolismo do Ferro/metabolismo , Pessoa de Meia-Idade , Distrofias Neuroaxonais/metabolismo , Neurônios/metabolismo
10.
PLoS One ; 14(5): e0216368, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31075107

RESUMO

Acute myeloid leukemia (AML) is the most common form of adult acute leukemia with ~20,000 new cases yearly. The disease develops in people of all ages, but is more prominent in the elderly, who due to limited treatment options, have poor overall survival rates. Monoclonal antibodies (mAb) targeting specific cell surface molecules have proven to be safe and effective in different haematological malignancies. However, AML target molecules are currently limited so discovery of new targets would be highly beneficial to patients. We examined the C-type lectin receptor CD302 as a potential therapeutic target for AML due to its selective expression in myeloid immune populations. In a cohort of 33 AML patients with varied morphological and karyotypic classifications, 88% were found to express CD302 on the surface of blasts and 80% on the surface of CD34+ CD38- population enriched with leukemic stem cells. A mAb targeting human CD302 was effective in mediating antibody dependent cell cytotoxicity and was internalised, making it amenable to toxin conjugation. Targeting CD302 with antibody limited in vivo engraftment of the leukemic cell line HL-60 in NOD/SCID mice. While CD302 was expressed in a hepatic cell line, HepG2, this molecule was not detected on the surface of HepG2, nor could HepG2 be killed using a CD302 antibody-drug conjugate. Expression was however found on the surface of haematopoietic stem cells suggesting that targeting CD302 would be most effective prior to haematopoietic transplantation. These studies provide the foundation for examining CD302 as a potential therapeutic target for AML.


Assuntos
Antígenos de Neoplasias/metabolismo , Antineoplásicos Imunológicos/farmacologia , Crise Blástica , Sistemas de Liberação de Medicamentos , Lectinas Tipo C/metabolismo , Leucemia Mieloide Aguda , Células-Tronco Neoplásicas , Receptores de Superfície Celular/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Crise Blástica/tratamento farmacológico , Crise Blástica/metabolismo , Crise Blástica/patologia , Feminino , Células HL-60 , Transplante de Células-Tronco Hematopoéticas , Células Hep G2 , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Biochim Biophys Acta ; 1773(2): 254-63, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17150266

RESUMO

The tumor necrosis factor alpha (TNFalpha) plays a dual role in producing either neurodegeneration or neuroprotection in the central nervous system. Despite that TNFalpha was initially described as a cell death inductor, neuroprotective effects against cell death induced by several neurotoxic insults have been reported. Tau hyperphosphorylation and neuronal death found in Alzheimer disease is mediated by deregulation of the cdk5/p35 complex induced by Abeta treatments. Since TNFalpha affects cdk5 activity, we investigated its possible protective role against the Abeta-induced neurodegeneration, as mediated by cdk5. TNFalpha pretreatments significantly reduced the hippocampal neuronal cell death induced by the effects of Abeta(42) peptide. In addition, this pretreatment reduced the increase in the activity of cdk5 induced by Abeta(42) in primary neurons. Next, we investigated the Alzheimer type phosphorylation of tau protein induced by Abeta(42). We observed that the pretreatment of neurons with TNFalpha reduces tau hyperphosphorylation. Taken together, these results define a novel neuroprotective effect of TNFalpha in preventing neuronal cell death and cdk5-dependent tau hyperphosphorylation. This phenomenon, taken together with other previous findings, suggests that the inflammatory response due to Abeta peptide plays a key role in the development of Alzheimer etiopathogenesis.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Quinase 5 Dependente de Ciclina/metabolismo , Fármacos Neuroprotetores/farmacologia , Neurotoxinas/toxicidade , Fragmentos de Peptídeos/toxicidade , Fator de Necrose Tumoral alfa/farmacologia , Doença de Alzheimer/patologia , Animais , Agregação Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/embriologia , Quinase 5 Dependente de Ciclina/genética , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Humanos , Mitocôndrias/efeitos dos fármacos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Proteínas tau/metabolismo
12.
Cytometry B Clin Cytom ; 94(4): 695-698, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29072803

RESUMO

BACKGROUND: Detection and quantitation of fetomaternal hemorrhage (FMH) can be difficult in patients with pre-existing elevations of HbF, such as those with hemoglobinopathies. The aim of this study was to evaluate the utility of dual-color flow cytometry with the Fetal Cell Count Kit (FCCK) in differentiating adult and fetal HbF in this population, as compared to flow cytometry (FC) using HbF alone. METHODS: Peripheral blood was obtained from normal adults and patients with hemoglobinopathies (ß-thalassemia and sickle cell disease), including a small number of pregnant females. Cord blood was used to spike some samples with 5% fetal cells. Analysis by single color (HbF) and dual-color (HbF and carbonic anhydrase) FC was performed on these samples. Fetal cells were defined as those with high HbF fluorescence on single-color FC, and those that were HbF + CA- using the FCCK. The quantity of fetal cells detected by each technique was compared. RESULTS: Forty-six adult patients were included. In non-pregnant adults with hemoglobinopathies, a population of red cells with a fetal cell phenotype were detected by both techniques. The dual-color method reported lower quantities of these cells. In nineteen samples spiked with cord blood the FCCK consistently underestimated the quantity of fetal cells. CONCLUSIONS: Patients with ß-thalassemia and sickle cell disease have a population of HbF-containing cells which are phenotypically similar to fetal cells. Even with dual-color flow cytometry (FCCK), the detection and quantification of FMH by flow cytometry in this population remains difficult. © 2017 International Clinical Cytometry Society.


Assuntos
Hemoglobina Fetal/análise , Transfusão Feto-Materna/sangue , Citometria de Fluxo/métodos , Hemoglobinopatias/sangue , Complicações Hematológicas na Gravidez/sangue , Adulto , Feminino , Transfusão Feto-Materna/diagnóstico , Hemoglobinopatias/diagnóstico , Hemoglobinas/análise , Humanos , Fenótipo , Gravidez , Complicações Hematológicas na Gravidez/diagnóstico
13.
Oncoimmunology ; 7(4): e1419114, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29632738

RESUMO

Only modest advances in AML therapy have occurred in the past decade and relapse due to residual disease remains the major challenge. The potential of the immune system to address this is evident in the success of allogeneic transplantation, however this leads to considerable morbidity. Dendritic cell (DC) vaccination can generate leukemia-specific autologous immunity with little toxicity. Promising results have been achieved with vaccines developed in vitro from purified monocytes (Mo-DC). We now demonstrate that blood DC (BDC) have superior function to Mo-DC. Whilst BDC are reduced at diagnosis in AML, they recover following chemotherapy and allogeneic transplantation, can be purified using CMRF-56 antibody technology, and can stimulate functional T cell responses. While most AML patients in remission had a relatively normal T cell landscape, those who had received fludarabine as salvage therapy have persistent T cell abnormalities including reduced number, altered subset distribution, failure to expand, and increased activation-induced cell death. Furthermore, PD-1 and TIM-3 are increased on CD4T cells in AML patients in remission and their blockade enhances the expansion of leukemia-specific T cells. This confirms the feasibility of a BDC vaccine to consolidate remission in AML and suggests it should be tested in conjunction with checkpoint blockade.

14.
EMBO Mol Med ; 8(10): 1197-1211, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27516453

RESUMO

Pantothenate kinase-associated neurodegeneration (PKAN) is an early onset and severely disabling neurodegenerative disease for which no therapy is available. PKAN is caused by mutations in PANK2, which encodes for the mitochondrial enzyme pantothenate kinase 2. Its function is to catalyze the first limiting step of Coenzyme A (CoA) biosynthesis. We generated induced pluripotent stem cells from PKAN patients and showed that their derived neurons exhibited premature death, increased ROS production, mitochondrial dysfunctions-including impairment of mitochondrial iron-dependent biosynthesis-and major membrane excitability defects. CoA supplementation prevented neuronal death and ROS formation by restoring mitochondrial and neuronal functionality. Our findings provide direct evidence that PANK2 malfunctioning is responsible for abnormal phenotypes in human neuronal cells and indicate CoA treatment as a possible therapeutic intervention.


Assuntos
Coenzima A/metabolismo , Neurônios/patologia , Neurodegeneração Associada a Pantotenato-Quinase/fisiopatologia , Fosfotransferases (Aceptor do Grupo Álcool)/deficiência , Morte Celular , Células Cultivadas , Humanos , Mitocôndrias/patologia , Células-Tronco Pluripotentes/fisiologia , Espécies Reativas de Oxigênio/metabolismo
15.
Front Cell Neurosci ; 7: 175, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24109433

RESUMO

Most human neuronal disorders are associated with genetic alterations that cause defects in neuronal development and induce precocious neurodegeneration. In order to fully characterize the molecular mechanisms underlying the onset of these devastating diseases, it is important to establish in vitro models able to recapitulate the human pathology as closely as possible. Here we compared three different differentiation protocols for obtaining functional neurons from human induced pluripotent stem cells (hiPSCs): human neural progenitors (hNPs) obtained from hiPSCs were differentiated by co-culturing them with rat primary neurons, glial cells or simply by culturing them on matrigel in neuronal differentiation medium, and the differentiation level was compared using immunofluorescence, biochemical and electrophysiological methods. We show that the differentiated neurons displayed distinct maturation properties depending on the protocol used and the faster morphological and functional maturation was obtained when hNPs were co-cultured with rat primary neurons.

17.
Rev. méd. Chile ; 145(12): 1551-1558, dic. 2017. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-902480

RESUMO

Background Campylobacter jejuni is one of the main causal agents of food borne diseases. Infections with this pathogen are mainly caused by chicken meat consumption. Aim To characterize antibiotic resistance and virulence factors in C. jejuni strains obtained from chicken meat and poultry feces in Central Chile. Material and Methods The presence of C. jejuni in 30 meat and 40 feces samples from poultry was studied. From these samples, we obtained 40 strains which were characterized at the molecular level for the presence of 16 genes involved in virulence using PCR. In parallel, antibiotic resistance for ciprofloxacin, nalidixic acid, tetracycline, erythromycin, azithromycin, chloramphenicol y ampicillin was analyzed. Results Twenty and 63% of feces and chicken meat samples were positive for C. jejuni, respectively. Moreover, a high percentage of strains showed antibiotic resistance, where 27% of strains were resistant to all tested antibiotics, except for azithromycin. Finally, 10% of the strains coming from feces contained 14 out of 16 virulence genes evaluated. Only 23% of the strains did not contain any of these genes. Conclusions A high percentage of feces and chicken meat samples are contaminated with C. jejuni. Moreover, these strains show a high genetic and phenotypic diversity represented by their antibiotic resistance profiles and the presence of virulence factors.


Assuntos
Animais , Produtos Avícolas/microbiologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/patogenicidade , Fezes/microbiologia , Antibacterianos/farmacologia , Valores de Referência , DNA Bacteriano , Testes de Sensibilidade Microbiana , Galinhas , Reação em Cadeia da Polimerase , Campylobacter jejuni/isolamento & purificação , Campylobacter jejuni/genética , Farmacorresistência Bacteriana , Fatores de Virulência
18.
Geogr Anal ; 43(3): 241-60, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22073410

RESUMO

One of the main tasks in analyzing pedestrian movement is to detect places where pedestrians stop, as those places usually are associated with specific human activities, and they can allow us to understand pedestrian movement behavior. Very few approaches have been proposed to detect the locations of stops in positioning data sets, and they often are based on selecting the location of candidate stops as well as potential spatial and temporal thresholds according to different application requirements. However, these approaches are not suitable for analyzing the slow movement of pedestrians where the inaccuracy of a nondifferential global positioning system commonly used for movement tracking is so significant that it can hinder the selection of adequate thresholds. In this article, we propose an exploratory statistical approach to detect patterns of movement suspension using a local indicator of spatial association (LISA) in a vector space representation. Two different positioning data sets are used to evaluate our approach in terms of exploring movement suspension patterns that can be related to different landscapes: players of an urban outdoor mobile game and visitors of a natural park. The results of both experiments show that patterns of movement suspension were located at places such as checkpoints in the game and different attractions and facilities in the park. Based on these results, we conclude that using LISA is a reliable approach for exploring movement suspension patterns that represent the places where the movement of pedestrians is temporally suspended by physical restrictions (e.g., checkpoints of a mobile game and the route choosing points of a park).


Assuntos
Cidades , Saúde Pública , Comportamento Espacial , Meios de Transporte , Caminhada , Cidades/economia , Cidades/etnologia , Cidades/história , Cidades/legislação & jurisprudência , História do Século XX , História do Século XXI , Saúde Pública/economia , Saúde Pública/educação , Saúde Pública/história , Saúde Pública/legislação & jurisprudência , Segurança/economia , Segurança/história , Segurança/legislação & jurisprudência , Meios de Transporte/economia , Meios de Transporte/história , Meios de Transporte/legislação & jurisprudência , Caminhada/economia , Caminhada/educação , Caminhada/história , Caminhada/legislação & jurisprudência , Caminhada/fisiologia , Caminhada/psicologia
19.
Methods Mol Biol ; 661: 205-20, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20811985

RESUMO

Accumulating evidence indicates that p44(ERK1) and p42(ERK2) mitogen-activated protein kinases (MAPKs) have distinct quantitative roles in cell signaling. In our recently proposed model of regulation of ERK1 and ERK2, p42 plays a major role in delivering signals from the cell membrane to the nucleus, while p44 acts as a partial agonist of ERK2 toward effectors and downstream activators, thus providing a fine tuning system of the global signaling output. Here, we describe systems to modulate MAPK signaling in vitro and in vivo via lentiviral vector (LV)-mediated gene transfer, using three systems: RNAi with small hairpin RNAs, microRNA-mediated gene knockdown, and expression of signaling-interfering mutants of MEK1. We show, by using proliferation assays in mouse embryo fibroblasts (MEF) and NIH 3T3 cells, that gene knockdown of ERK1 promotes cell proliferation in a manner indistinguishable from a constitutively active MEK1 construct, while ERK2 RNAi causes a significant growth arrest, similar to that observed with the ectopic expression of a dominant negative MEK1 mutant.


Assuntos
Ensaios Enzimáticos/métodos , Vetores Genéticos/genética , Lentivirus/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Animais , Fosfatos de Cálcio/metabolismo , Proliferação de Células , Técnicas de Silenciamento de Genes , Humanos , Camundongos , MicroRNAs/genética , Proteína Quinase 1 Ativada por Mitógeno/deficiência , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/deficiência , Proteína Quinase 3 Ativada por Mitógeno/genética , Células NIH 3T3 , RNA Interferente Pequeno/genética , Transfecção
20.
J Cell Biochem ; 100(3): 738-49, 2007 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-17009320

RESUMO

The cdk5/p35 complex has been implicated in a variety of functions related to brain development, including axonal outgrown and neuronal migration. In this study, by co-immunoprecipitation and pull-down experiments, we have shown that the cdk5/p35 complex associates with and phosphorylates the neuronal delta-catenin. Immunocytochemical studies of delta-catenin and the cdk5-activator p35 in primary cortical neurons indicated that these proteins co-localize in the cell body of neuronal cells. In addition, cdk5 co-localized with beta-catenin in the cell-cell contacts and plasma membrane of undifferentiated and differentiated N2A cells. In this context, we identified Ser(191) and Ser(246) on beta-catenin structure as specific phosphorylation sites for cdk5/p35 complex. Moreover, Pin1, a peptidyl-prolyl isomerase (PPIase) directly bound to both, beta- and delta-catenin, once they have been phosphorylated by the cdk5/p35 complex. Studies indicate that the cdk5/p35 protein kinase system is directly involved in the regulatory mechanisms of neuronal beta- and delta-catenin.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Quinase 5 Dependente de Ciclina/fisiologia , Neurônios/metabolismo , beta Catenina/metabolismo , gama Catenina/metabolismo , Animais , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Imunofluorescência , Mutagênese Sítio-Dirigida , Fosforilação , Ligação Proteica , Ratos , Ratos Sprague-Dawley , beta Catenina/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA