Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 176
Filtrar
1.
J Appl Stat ; 51(5): 826-844, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38524797

RESUMO

The aim of this study is to propose a generalized odd log-logistic Maxwell mixture model to analyze the effect of gender and age groups on lifetimes and on the recovery probabilities of Chinese individuals with COVID-19. We add new properties of the generalized Maxwell model. The coefficients of the regression and the recovered fraction are estimated by maximum likelihood and Bayesian methods. Further, some simulation studies are done to compare the regressions for different scenarios. Model-checking techniques based on the quantile residuals are addressed. The estimated survival functions for the patients are reported by age range and sex. The simulation study showed that mean squared errors decay toward zero and the average estimates converge to the true parameters when sample size increases. According to the fitted model, there is a significant difference only in the age group on the lifetime of individuals with COVID-19. Women have higher probability of recovering than men and individuals aged ≥60 years have lower recovered probabilities than those who aged <60 years. The findings suggest that the proposed model could be a good alternative to analyze censored lifetime of individuals with COVID-19.

2.
J Appl Stat ; 50(8): 1665-1685, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37260477

RESUMO

Among the models applied to analyze survival data, a standout is the inverse Gaussian distribution, which belongs to the class of models to analyze positive asymmetric data. However, the variance of this distribution depends on two parameters, which prevents establishing a functional relation with a linear predictor when the assumption of constant variance does not hold. In this context, the aim of this paper is to re-parameterize the inverse Gaussian distribution to enable establishing an association between a linear predictor and the variance. We propose deviance residuals to verify the model assumptions. Some simulations indicate that the distribution of these residuals approaches the standard normal distribution and the mean squared errors of the estimators are small for large samples. Further, we fit the new model to hospitalization times of COVID-19 patients in Piracicaba (Brazil) which indicates that men spend more time hospitalized than women, and this pattern is more pronounced for individuals older than 60 years. The re-parameterized inverse Gaussian model proved to be a good alternative to analyze censored data with non-constant variance.

3.
J Appl Stat ; 49(16): 4137-4161, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36353297

RESUMO

We propose a new continuous distribution in the interval ( 0 , 1 ) based on the generalized odd log-logistic-G family, whose density function can be symmetrical, asymmetric, unimodal and bimodal. The new model is implemented using the gamlss packages in R. We propose an extended regression based on this distribution which includes as sub-models some important regressions. We employ a frequentist and Bayesian analysis to estimate the parameters and adopt the non-parametric and parametric bootstrap methods to obtain better efficiency of the estimators. Some simulations are conducted to verify the empirical distribution of the maximum likelihood estimators. We compare the empirical distribution of the quantile residuals with the standard normal distribution. The extended regression can give more realistic fits than other regressions in the analysis of proportional data.

4.
J Appl Stat ; 47(12): 2159-2177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-35706842

RESUMO

The multinomial logistic regression model (MLRM) can be interpreted as a natural extension of the binomial model with logit link function to situations where the response variable can have three or more possible outcomes. In addition, when the categories of the response variable are nominal, the MLRM can be expressed in terms of two or more logistic models and analyzed in both frequentist and Bayesian approaches. However, few discussions about post modeling in categorical data models are found in the literature, and they mainly use Bayesian inference. The objective of this work is to present classic and Bayesian diagnostic measures for categorical data models. These measures are applied to a dataset (status) of patients undergoing kidney transplantation.

5.
Scand J Immunol ; 83(2): 109-18, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26524607

RESUMO

The incidence of non-alcoholic steatohepatitis (NASH) is increasing. Because gut microbiota have been highlighted as one of the key factors in the pathogenesis of metabolic syndrome, we investigated the involvement of the bacterial component in the progression of non-alcoholic fatty liver (NAFL) to NASH. C57BL/6 mice were fed with maintenance food (MF, groups A and B) or a high caloric diet (HCD, groups C and D) for 1 month. Mice were then divided into four groups: Groups A and C were inoculated with PBS, while groups B and D were inoculated with lipopolysaccharide (LPS) plus complete Freund's adjuvant (CFA). The inoculations were performed a total of 3 times over 3 months. At 6 months, while hepatic steatosis was observed in groups C and D, cellular infiltration and fibrosis were less evident in group C than in group D. Inflammatory cytokines were upregulated in groups B and D. 16S rRNA pyrosequencing of whole colon homogenates containing faeces showed that certain bacterial groups, such as Bacteroidaceae, Peptostreptococcaceae and Erysipelotrichaceae, were increased in groups C and D. Although loading of bacterial components (LPS) resulted in hepatic inflammation in both MF- and HCD-fed mice, HCD feeding was more crucial in the progression of NAFL during the triggering phase.


Assuntos
Lipopolissacarídeos/toxicidade , Hepatopatia Gordurosa não Alcoólica/etiologia , Animais , Colo/imunologia , Colo/microbiologia , Colo/patologia , Citocinas/genética , Dieta/efeitos adversos , Modelos Animais de Doenças , Progressão da Doença , Ingestão de Energia , Microbioma Gastrointestinal/genética , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/microbiologia , Hepatopatia Gordurosa não Alcoólica/patologia , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação
6.
J. Gastroenterol ; 50(4)Apr. 2015.
Artigo em Inglês | BIGG - guias GRADE | ID: biblio-965639

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease in industrialized countries worldwide, and has become a serious public health issue not only in Western countries but also in many Asian countries including Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease, which often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma. In turn, a large proportion of NAFLD/NASH is the liver manifestation of metabolic syndrome, suggesting that NAFLD/NASH plays a key role in the pathogenesis of systemic atherosclerotic diseases. Currently, a definite diagnosis of NASH requires liver biopsy, though various noninvasive measures are under development. The mainstays of prevention and treatment of NAFLD/NASH include dietary restriction and exercise; however, pharmacological approaches are often necessary. Currently, vitamin E and thiazolidinedione derivatives are the most evidence-based therapeutic options, although the clinical evidence for long-term efficacy and safety is limited. This practice guideline for NAFLD/NASH, established by the Japanese Society of Gastroenterology in cooperation with The Japan Society of Hepatology, covers lines of clinical evidence reported internationally in the period starting from 1983 to January 2012, and each clinical question was evaluated using the GRADE system. Based on the primary release of the full version in Japanese, this English summary provides the core essentials of this clinical practice guideline comprising the definition, diagnosis, and current therapeutic recommendations for NAFLD/NASH in Japan.(AU)


Assuntos
Humanos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Vitamina E/uso terapêutico , Transplante de Fígado , Tiazolidinedionas/uso terapêutico , Cirurgia Bariátrica
7.
Diabetes Obes Metab ; 16(6): 573-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24320758

RESUMO

This study was performed to clarify the influence of liraglutide on gastric emptying in Japanese patients with type 2 diabetes. In 16 patients, the [(13) C]-acetate breath test was performed to compare gastric emptying before and after liraglutide treatment. We found two patterns of response, with gastric emptying being delayed by liraglutide in seven patients (delayers) and not delayed in nine patients (non-delayers). The mean increase of the maximum gastric emptying time was 31 ± 4 min (p < 0.01 vs. baseline) in the delayers, while it was only 2 ± 3 min (p = 0.60 vs. baseline) in the non-delayers. The delayers showed a greater early decrease of AUC-PG from 0 to 60 min, despite no increase of the plasma insulin level compared with non-delayers. In conclusion, the effect of liraglutide treatment on gastric emptying shows heterogeneity, and patients can be classified as delayers or non-delayers.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Esvaziamento Gástrico/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Hipoglicemiantes/administração & dosagem , Adulto , Idoso , Povo Asiático , Glicemia/efeitos dos fármacos , Testes Respiratórios , Feminino , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Peptídeo 1 Semelhante ao Glucagon/efeitos adversos , Humanos , Hipoglicemiantes/efeitos adversos , Liraglutida , Masculino , Pessoa de Meia-Idade , Taquifilaxia
8.
Transl Psychiatry ; 2: e188, 2012 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-23149452

RESUMO

To better understand the cellular pathogenetic mechanisms of fetal alcohol spectrum disorder (FASD) and the therapeutic benefit of stem cell treatment, we exposed pregnant rats to ethanol followed by intravenous administration of neural stem cells (NSCs) complexed with atelocollagen to the new born rats and studied recovery of GABAergic interneuron numbers and synaptic protein density in the anterior cingulate cortex, hippocampus and amygdala. Prenatal ethanol exposure reduced both parvalbumin-positive phenotype of GABAergic interneurons and postsynaptic density protein 95 levels in these areas. Intravenous NSC treatment reversed these reductions. Furthermore, treatment with NSCs reversed impaired memory/cognitive function and social interaction behavior. These experiments underscore an important role for synaptic remodeling and GABAergic interneuron genesis in the pathophysiology and treatment of FASD and highlight the therapeutic potential for intravenous NSC administration in FASD utilizing atelocollagen.


Assuntos
Transtornos do Espectro Alcoólico Fetal/terapia , Transtornos da Memória/terapia , Células-Tronco Neurais/transplante , Reconhecimento Psicológico , Tonsila do Cerebelo/metabolismo , Tonsila do Cerebelo/fisiopatologia , Animais , Animais Recém-Nascidos , Comportamento Animal , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/terapia , Modelos Animais de Doenças , Feminino , Transtornos do Espectro Alcoólico Fetal/metabolismo , Transtornos do Espectro Alcoólico Fetal/fisiopatologia , Neurônios GABAérgicos/metabolismo , Giro do Cíngulo/metabolismo , Giro do Cíngulo/fisiopatologia , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Interneurônios/metabolismo , Transtornos da Memória/metabolismo , Transtornos da Memória/fisiopatologia , Gravidez , Ratos , Ratos Wistar , Comportamento Social , Transplante de Células-Tronco
9.
J Physiol Pharmacol ; 63(1): 41-52, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22460460

RESUMO

We set up a new model of gastric bleeding induced by the luminal perfusion of aspirin (ASA) in rats pretreated with clopidogrel under conditions where acid secretion is stimulated, and examined the effect of antiulcer drugs on the bleeding. Under urethane anesthesia, acid secretion was stimulated by i.v. infusion of histamine (8 mg/kg/h), and two catheters were inserted into the stomach, one from the esophagus and another from the duodenum. The stomach was perfused with 25 mM ASA at a rate of 0.1 ml/min using an infusion pump, and gastric bleeding was measured as hemoglobin concentration in the perfusate collected every 15 min. Clopidogrel (30 mg/kg) was given orally 24 h before the perfusion. Various antiulcer drugs were given intraduodenally 30 min before the ASA treatment. Perfusion of the stomach with ASA provoked little gastric bleeding or damage even when acid secretion was stimulated. Pretreatment with clopidogrel significantly increased the bleeding and damage caused by ASA. The bleeding and lesions produced by ASA plus clopidogrel were significantly prevented by pretreatment with famotidine and omeprazole. Mucosal protective drugs such as rebamipide, irsogladine and teprenone also prevented gastric bleeding response to ASA/clopidogrel under conditions of acid secretion, although the effect was less pronounced than that of the antisecretory drugs. We conclude that clopidogrel increases gastric bleeding induced by ASA when acid secretion is stimulated. Both antisecretory and mucosal protective drugs are effective in reducing gastric bleeding under such conditions. This model is useful for the screening of drugs that protect against gastric bleeding.


Assuntos
Antiulcerosos/farmacologia , Hemorragia Gastrointestinal/tratamento farmacológico , Úlcera Gástrica/tratamento farmacológico , Animais , Aspirina , Clopidogrel , Interações Medicamentosas , Famotidina/farmacologia , Ácido Gástrico/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/metabolismo , Hemorragia Gastrointestinal/patologia , Masculino , Omeprazol/farmacologia , Peroxidase/metabolismo , Ratos , Ratos Sprague-Dawley , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/metabolismo , Úlcera Gástrica/patologia , Ticlopidina/análogos & derivados
10.
J Fish Dis ; 31(6): 443-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18471100

RESUMO

Kuchijirosho is a fatal disease of commercially cultured fugu, Takifugu rubripes. The transmissible nature of kuchijirosho strongly suggests that an infectious pathogen is the causative agent. Because it is filtrable, the agent is thought to be a virus; however, it has not yet been identified. The lack of a permissive cell line for the putative kuchijirosho-causing agent (KCA) has hindered research on the identification of this pathogen. We inoculated brain extract prepared from kuchijirosho-affected fugu onto an established fugu cell line, fugu eye, and observed that cytopathic effect appeared 7 days after inoculation. Injection of the culture medium of infected fugu eye cells into fugu resulted in the onset of kuchijirosho, indicating that fugu eye cells are able to proliferate KCA. An infectious fraction separated by sodium iottalamate density gradient centrifugation showed a density of 1.15 g mL(-1) equivalent to that of KCA derived from affected fugu brain. To determine whether the genome of KCA is RNA or DNA based, nucleotide synthesis inhibitors were applied to inoculated fugu eye cell line to influence the production of KCA. 5-Fluorouracil but not IUdR showed a concentration-dependent inhibition of KCA yield. These results suggest that KCA is an RNA virus.


Assuntos
Doenças dos Peixes/virologia , Infecções por Vírus de RNA/veterinária , Vírus de RNA/fisiologia , Takifugu/virologia , Replicação Viral , Animais , Antimetabólitos/farmacologia , Linhagem Celular , Centrifugação com Gradiente de Concentração , Efeito Citopatogênico Viral , Doenças dos Peixes/mortalidade , Doenças dos Peixes/patologia , Infecções por Vírus de RNA/mortalidade , Infecções por Vírus de RNA/patologia , Infecções por Vírus de RNA/virologia , Vírus de RNA/efeitos dos fármacos , Vírus de RNA/isolamento & purificação , Vírus de RNA/patogenicidade , Fatores de Tempo , Replicação Viral/efeitos dos fármacos
11.
J Neural Transm Suppl ; (72): 331-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17982911

RESUMO

Neural stem cell (NSC) transplantation has been investigated and developed in areas such as brain injury, stroke and neurodegenerative diseases. Recently, emerging evidence suggest that many of clinical symptoms observed in psychiatric disease are likely related to neural network disruptions including neurogenesis dysfunction. In the present study, we transplanted NSCs into a model of fetal alchol effects (FAE) for the purpose of investigating the possibility of regenerative therapy for the FAE. We labeled NSCs with fluorescent dye and radioisotope which were transplanted into FAE rats by intravenous injection. The transplanted cells were detected in wide areas of brain and were greater in number in the brains of the FAE group compared to the control group. Furthermore NSC transplantation attenuated behavioral abnormalities in FAE animals. These results suggest NSC transplantation as a potental new therapy for human FAE.


Assuntos
Modelos Animais de Doenças , Células-Tronco Embrionárias/transplante , Transtornos do Espectro Alcoólico Fetal/cirurgia , Regeneração Nervosa/fisiologia , Neurônios/citologia , Animais , Animais Recém-Nascidos , Encéfalo/patologia , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Células-Tronco Embrionárias/patologia , Comportamento Exploratório/fisiologia , Medo/fisiologia , Feminino , Transtornos do Espectro Alcoólico Fetal/patologia , Humanos , Injeções Intravenosas , Aprendizagem em Labirinto/fisiologia , Microscopia de Fluorescência , Neurônios Motores/fisiologia , Neurônios/patologia , Gravidez , Ratos , Ratos Wistar
12.
J Neural Transm (Vienna) ; 114(9): 1121-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17557129

RESUMO

Recent clinical neuroimaging studies have suggested that morphological brain changes occur and progress in the course of schizophrenia. Although the neurogenetic and neurotrophic effects of antipsychotics are considered to contribute to the prevention of reduction in brain volume, the cellular molecular mechanisms of action of antipsychotics have not yet been elucidated. We examined the effects of antipsychotics on the endoplasmic reticulum (ER) stress-induced damages of neurons and neural stem cells (NSCs) using cultured cells. In the neuronal cultures, the atypical antipsychotic olanzapine protected neurons from thapsigargin (1 microM)-induced injury. It was observed that a low concentration of thapsigargin (10 nM) that did not affect the neuronal survival could reduce neuronal differentiation of cultured NSCs, suggesting a role of ER stress in the differentiation function of NSCs. Treatment with olanzapine increased the neuronal differentiation suppressed by the exposure to thapsigargin (10 nM). The thapsigargin-induced ER chaperones, GRP78, which indicate the ER stress condition of the cell, were decreased by the treatment with the atypical antipsychotics olanzapine and quetiapine but not by the typical antipsychotic haloperidol. These results indicate that the amelioration of ER-stress might be involved in the cellular mechanisms of atypical antipsychotics to produce neuroprotective and neurogenetic actions in neurons and NSCs, suggesting potential roles of these drugs for treatment of schizophrenia.


Assuntos
Antipsicóticos/farmacologia , Benzodiazepinas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Proteínas de Choque Térmico/biossíntese , Neurônios/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Animais , Diferenciação Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Sinergismo Farmacológico , Retículo Endoplasmático/fisiologia , Feminino , Proteínas de Choque Térmico/fisiologia , Neurônios/fisiologia , Olanzapina , Gravidez , Ratos , Ratos Wistar , Células-Tronco/citologia , Células-Tronco/fisiologia
13.
J Neural Transm (Vienna) ; 113(3): 283-93, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15959844

RESUMO

The neuron-restrictive silencer factor (NRSF), or repressor element-1 silencing transcription factor (REST), is a transcription factor that mediates negative regulation of neuronal genes. NRSF represses multiple neuronal target genes in non-neuronal and neuronal precursor cells to regulate the proper timing of neuronal gene expression during neurogenesis. In the present study, we investigated the effects of ethanol and MEK inhibitor U0126 on the DNA binding activity of NRSF in neural stem cells prepared from rat embryos. Both ethanol and U0126 enhanced NRSF binding activity measured by the method based on the principal of electrophoretic mobility shift assay (EMSA) and decreased neuronal differentiation in a concentration dependent manner. Western blot analysis revealed that ethanol suppressed phosphorylation of extracellular signal-regulated kinase (ERK) without affecting expression of total ERK. These results suggest that ethanol-induced potentiation of NRSF binding activity underlies the mechanism of ethanol inhibition of neuronal differentiation and decreased neurogenesis.


Assuntos
Transtornos do Sistema Nervoso Induzidos por Álcool/metabolismo , Encéfalo/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Etanol/toxicidade , Neurônios/efeitos dos fármacos , Proteínas Repressoras/efeitos dos fármacos , Fatores de Transcrição/efeitos dos fármacos , Transtornos do Sistema Nervoso Induzidos por Álcool/fisiopatologia , Animais , Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiopatologia , Diferenciação Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Depressores do Sistema Nervoso Central/toxicidade , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/genética , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Células-Tronco Pluripotentes/metabolismo , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Ratos , Ratos Wistar , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
14.
J Neural Transm (Vienna) ; 112(8): 1005-13, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15583957

RESUMO

Ethanol-induced cell damage was investigated using human neuroblastomas SH-SY5Y cells, which can be differentiated by retinoic acid. With 100 mM or more of ethanol, cytotoxicity was significantly higher in undifferentiated cells than in differentiated cells. Thus, a severer effect of ethanol was observed in undifferentiated cells. In differentiated cells it was shown that the secreted amount of brain derived neurotrophic factor (BDNF) and the cyclic AMP responsive element binding protein (CREB) activity were significantly reduced by ethanol. These effects may be involved in ethanol-induced cell damage in differentiated cells. It was reported that neurotrophic factors have protective effects and that the hippocampus exclusively was damaged by ethanol. Since SH-SY5Y cell is a cell line (a neuronal cell model) and similar cytotoxic effect of ethanol was observed in both SH-SY5Y and primary culture neuronal cells, it will be favorable to use primary culture cells to test a protective effect of BDNF. Exogenous BDNF was shown to have a protective effect against ethanol-induced damage in primary culture neurons from rat hippocampi.


Assuntos
Transtornos do Sistema Nervoso Induzidos por Álcool/tratamento farmacológico , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Encéfalo/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Etanol/antagonistas & inibidores , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Transtornos do Sistema Nervoso Induzidos por Álcool/fisiopatologia , Transtornos do Sistema Nervoso Induzidos por Álcool/prevenção & controle , Animais , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Depressores do Sistema Nervoso Central/antagonistas & inibidores , Depressores do Sistema Nervoso Central/toxicidade , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Citoproteção/fisiologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Interações Medicamentosas/fisiologia , Etanol/toxicidade , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Humanos , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/metabolismo , Ratos , Resultado do Tratamento
15.
J Neural Transm (Vienna) ; 111(6): 667-81, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15168214

RESUMO

The neurotoxicity of conventional antipsychotic drugs has emerged as a potential pathogenic event in extrapyramidal side effects (EPS) and in their limited efficacy for negative-cognitive symptoms in schizophrenic patients. The atypical antipsychotics, recently developed, have superior therapeutic efficacy to treat not only positive symptoms but negative symptoms and cognitive dysfunctions with much lower potentials of side effects, although the influence of atypical antipsychotics on the regulation of neuronal survival has been less investigated. It is important to clarify the effects of typical and atypical antipsychotics on neuronal survival and their contributions to the therapeutic development and understanding of the pathophysiology of schizophrenia. We measured the neurotoxicity of two antipsychotic drug treatments, haloperidol and risperidone, in primary cultured rat cortical neurons. Immunoblotting and pharmacological agent analyses were used to determine the signal transduction changes implicated in the mechanisms of the neurotoxicity. Haloperidol induced apoptotic injury in cultured cortical neurons, but risperidone showed weak potential to injure the neurons. Treatment with haloperidol also led the reduction of phosphorylation levels of Akt, and activated caspase-3. The D2 agonist bromocriptine and 5-HT2A antagonist, ketanserin attenuated the haloperidol-induced neuronal toxicity. Moreover, brain-derived neurotrophic factor (BDNF) reduced the caspase-3 activity and protected neurons from haloperidol-induced apoptosis. BDNF also reversed the reduced levels of phosphorylation of Akt caused by treatment with haloperidol. Haloperidol but not risperidone induces caspase-dependent apoptosis by reducing cellular survival signaling, which possibly contributes to the differential clinical therapeutic efficacy and expression of side effects in schizophrenia.


Assuntos
Antagonistas de Dopamina/toxicidade , Haloperidol/toxicidade , Neurônios/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/efeitos dos fármacos , Proteínas Proto-Oncogênicas/efeitos dos fármacos , Risperidona/toxicidade , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Caspase 3 , Caspases/efeitos dos fármacos , Células Cultivadas , Embrião de Mamíferos , Imuno-Histoquímica , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Ratos Wistar
16.
J Neural Transm (Vienna) ; 111(3): 311-22, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14991457

RESUMO

We examined the quantity and quality of G proteins in membrane preparations of post-mortem human brain, i.e. in parietal, temporal and occipital cortical regions, from normal subjects over age (17-89 years old) and with Alzheimer's disease (AD) in comparison with aged-matched controls. In normal aging, the immunoreactivities determined of G(ialpha), G(qalpha) and G(beta) were inversely correlated with age. The function of G proteins was examined by photoaffinity GTP analogue [azidoanilido GTP (AAGTP)] labelling. AAGTP labelling to G(salpha) and G(i/oalpha), and the ratio of G(salpha) to G(i/oalpha) AAGTP labelling showed no age-dependent changes. In AD compared to age-matched controls, there were no significant differences in the levels of G(sHalpha), G(sLalpha), G(ialpha), G(oalpha), G(qalpha) and G(beta) subunits. Functional effects of G proteins, however, as measured by AAGTP labelling to G(salpha), but not to G(i/oalpha), was significantly decreased in AD compared to controls in the parietal and temporal cortex, but not in the occipital cortex. These results suggest that the disturbances of post-receptor trans-membrane signalling in AD can be attributed to functional changes of G(salpha), and these are independent of alterations in the level for those proteins in normal aging.


Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/metabolismo , Córtex Cerebral/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Guanosina Trifosfato/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Azidas , Estudos de Casos e Controles , Humanos , Immunoblotting , Pessoa de Meia-Idade , Marcadores de Fotoafinidade , Mudanças Depois da Morte , Membranas Sinápticas/metabolismo , Fatores de Tempo
17.
Food Addit Contam ; 19(11): 1081-90, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12456280

RESUMO

The effect of storage on mycoflora profile was monitored bimonthly in 36 corn (Zea mays L.) samples, dividing the same sample into groups dried to 11 and 14% moisture content (1008 analysis). These groups were further subdivided based on the initial total count (moulds and yeasts) up to 10(4) CFU g(-1) (12 samples, range 1.6 x 10(4) to 9.0 x 10(4), mean 3.8 x 10(4) CFU g(-1)) and up to 10(5) CFU g(-1) (24 samples, range 1.0 x 10(5) to 5.0 x 10(5), mean 2.7 x 10(5) CFU g(-1)). In the corn group dried to 11%, the fumonisin content was analysed at the initial stage (freshly harvested) and at the end of 12-month storage. Fusarium spp. and Penicillium spp. prevailed at the freshly harvested stage (100%), maintaining this profile throughout 12 months, in corn dried to both 11 and 14%. Cladosporium spp., Aspergillus spp. and Phoma spp. were also detected at lower frequencies during the storage. Fusarium spp. and the total fungal colony count during 12-month storage carried out with samples dried to 11 or 14% moisture content were statistically evaluated using ANOVA for randomized complete block design. The correlation between storage time and Fusarium spp. and total fungal colony count data was analysed by Pearson's correlation test. There was no difference in Fusarium spp. and total counts in the 10(4) CFU g(-1) initial total count group throughout the storage time (p < 0.05). There was a negative correlation between fungal population and storage time (p < 0.05) in the 10(5) CFU g(-1) initial total count group. Fumonisins were detected in all freshly harvested corn, at a mean concentration of 9.9 +/- 6.0 micro g g(-1) (range 0.74-22.6 micro g g(-)1). These values did not change in the 12-month stored corn (mean of 9.9 +/- 5.8 micro g g(-1), range 0.81-23.7 micro g g(-1)). These post harvest data indicated the importance of moisture content at the crop harvesting/predrying stage to control fungal growth and further fumonisin production.


Assuntos
Manipulação de Alimentos/métodos , Fumonisinas/análise , Zea mays/química , Zea mays/microbiologia , Agricultura/métodos , Animais , Aspergillus/metabolismo , Brasil , Cladosporium/metabolismo , Ensaio de Imunoadsorção Enzimática , Fungos , Fusarium/metabolismo , Humanos , Penicillium/metabolismo
18.
J Biochem Mol Biol Biophys ; 6(2): 107-11, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12186765

RESUMO

M(r) 25,000 protein (pp25) is a protein kinase substrate detected recently in Xenopus laevis oocytes [Hashimoto, E. et al. (1995) J. Biochem. 118, 453-460], but the physiological role of this protein remains to be determined. In order to elucidate some characteristics of pp25, a polyclonal antibody was raised against it and the distribution and quantitative changes of this protein were examined using various tissues and biological systems. In Western blot analysis, pp25 was detected only in Xenopus oocytes and not in other frog tissues when the heat-stable cytosolic fraction from each tissue was examined. Although the amount of pp25 apparently did not change during oocyte maturation induced by progesterone, pp25 disappeared in embryos around Nieuwkoop/Faber stages 45-48 in parallel with the change of pNiXa (a kind of serpin). These results suggest that pp25 plays some specific role(s) in Xenopus oocytes and that the level of pp25 changes dramatically during embryonic development.


Assuntos
Proteínas de Transporte/metabolismo , Oócitos/metabolismo , Proteínas Quinases/metabolismo , Proteínas/metabolismo , Serpinas/metabolismo , Proteínas de Xenopus , Xenopus laevis/embriologia , Xenopus laevis/metabolismo , Animais , Feminino , Técnicas In Vitro , Peso Molecular , Oócitos/crescimento & desenvolvimento , Proteínas/química , Especificidade por Substrato , Distribuição Tecidual
19.
J Gastroenterol ; 36(9): 637-42, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11578070

RESUMO

We report a case of living-related partial liver transplantation for decompensated hepatitis B without reactivation of hepatitis B in the following 30 months, and we analyze the factors that indicate a favorable prognosis for transplantation. The 42-year-old female patient received continuously administered lamivudine before transplantation, and hepatitis B virus immunoglobulin (HBIG) from the anhepatic phase to the present. Currently, she shows a normal aminotransferase level and is negative for hepatitis B surface antigen and hepatitis B virus (HBV) DNA by polymerase chain reaction amplification. Sequence analysis was performed. The entire precore/core region and part of the polymerase region of HBV were sequenced by a direct sequencing method after polymerase chain reaction. No specific mutation was found in these regions. These observations show that the key factors in the long-term successful treatment of this patient appear to be the combination therapy of lamivudine and HBIG that the patient received from around the time of the transplantation. Furthermore, the lack of specific mutations, including lamivudine resistant-mutations, is likely to represent an additional factor in the effectiveness of this treatment.


Assuntos
Hepatite B/cirurgia , Cirrose Hepática/cirurgia , Transplante de Fígado , Doadores Vivos , Adulto , Anticorpos/análise , Feminino , Hepatite B/tratamento farmacológico , Antígenos do Núcleo do Vírus da Hepatite B/análise , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/imunologia , Humanos , Imunoglobulinas/uso terapêutico , Lamivudina/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Reação em Cadeia da Polimerase/métodos , Inibidores da Transcriptase Reversa/uso terapêutico , Prevenção Secundária
20.
Alcohol ; 24(2): 107-10, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11522431

RESUMO

In this study, we attempted to determine the prevalence of tobacco or nicotine dependence in current smokers in Japan and to assess the relationship between alcoholism and tobacco or nicotine dependence. The subjects consisted of 246 alcohol-dependent and 1,111 non-alcohol-dependent individuals. We used a questionnaire, consisting of items obtained from the World Health Organization's The ICD-10 Classification of Mental and Behavioural Disorders: Clinical Descriptions and Diagnostic Guidelines (ICD-10) and the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria for tobacco or nicotine dependence. The prevalence of tobacco dependence diagnosed according to the ICD-10 criteria was 23.9% among all subjects. The prevalence of tobacco dependence diagnosed according to the ICD-10 criteria was higher in alcohol-dependent individuals (58.1%) than in nondrinkers or social drinkers (12.8%). Alcohol-dependent subjects consumed significantly more nicotine per day than did nondrinkers or social drinkers. The prevalence of nicotine physical dependence diagnosed by using DSM-IV criteria for nicotine withdrawal was 2.4% in alcohol-dependent individuals, whereas only 0.3% of nondrinkers or social drinkers exhibited nicotine physical dependence. These results indicate to us that the potential for nicotine physical dependence is not much stronger than that reported among current smokers.


Assuntos
Fumar/epidemiologia , Tabagismo/epidemiologia , Adulto , Idoso , Humanos , Japão , Pessoa de Meia-Idade , Nicotina/efeitos adversos , Prevalência , Abandono do Hábito de Fumar/estatística & dados numéricos , Síndrome de Abstinência a Substâncias/epidemiologia , Tabagismo/diagnóstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...