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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 7535-7538, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892835

RESUMO

The long-term goal of this study is a training system that can simulate medical cases and advise physicians based on quantitative evaluation of neonatal resuscitation. In this paper, we designed and manufactured a neonatal airway management simulator for quantitative evaluation of tracheal intubation. This robotic simulator is equipped with 25 sensors of 6 types, which detect motions that lead to complications, inside the manikin replicated a neonate. A performance experiment of the developed sensor and an evaluation experiment with physicians were conducted. We observed that an erroneous operation in the laryngoscopy can be detected by the sensors in our simulator.


Assuntos
Intubação Intratraqueal , Ressuscitação , Manuseio das Vias Aéreas , Humanos , Recém-Nascido , Laringoscopia , Manequins
2.
Neuroscience ; 297: 95-104, 2015 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-25841321

RESUMO

Attention-deficit/hyperactivity disorder (ADHD) is a complex neurobehavioral disorder that is characterized by attention difficulties, impulsivity, and hyperactivity. A non-stimulant drug, atomoxetine (ATX), which is a selective noradrenaline reuptake inhibitor, is widely used for ADHD because it exhibits fewer adverse effects compared to conventional psychostimulants. However, little is known about the therapeutic mechanisms of ATX. ATX treatment significantly alleviated hyperactivity of pituitary adenylate cyclase-activating polypeptide (PACAP)-deficient (PACAP(-/-)) mice with C57BL/6J and 129S6/SvEvTac hybrid background. ATX also improved impaired novel object recognition memory and prepulse inhibition in PACAP(-/-) mice with CD1 background. The ATX-induced increases in extracellular noradrenaline and dopamine levels were significantly higher in the prefrontal cortex of PACAP(-/-) mice compared to wild-type mice with C57BL/6J and 129S6/SvEvTac hybrid background. These results suggest that ATX treatment-induced increases in central monoamine metabolism may be involved in the rescue of ADHD-related abnormalities in PACAP(-/-) mice. Our current study suggests that PACAP(-/-) mice are an ideal rodent model with predictive validity for the study of ADHD etiology and drug development. Additionally, the potential effects of differences in genetic background of PACAP(-/-) mice on behaviors are discussed.


Assuntos
Inibidores da Captação Adrenérgica/uso terapêutico , Cloridrato de Atomoxetina/uso terapêutico , Transtornos Cognitivos/tratamento farmacológico , Hipercinese/tratamento farmacológico , Transtornos da Memória/tratamento farmacológico , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/deficiência , Inibição Pré-Pulso/efeitos dos fármacos , Estimulação Acústica , Análise de Variância , Animais , Monoaminas Biogênicas/metabolismo , Transtornos Cognitivos/genética , Relação Dose-Resposta a Droga , Comportamento Exploratório/efeitos dos fármacos , Hipercinese/etiologia , Transtornos da Memória/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microdiálise , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Reconhecimento Psicológico/efeitos dos fármacos
3.
Eur J Surg Oncol ; 39(1): 26-30, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23122913

RESUMO

AIM: The aim of this study was to assess the diagnostic performance of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in combination with ultrasonography-guided fine needle aspiration cytology (US-guided FNAC) for the preoperative diagnosis of axillary lymph node (ALN) metastases in patients with breast cancer. MATERIALS AND METHODS: A total of 318 patients with breast cancer were recruited retrospectively. Some of the cases that underwent neoadjuvant chemotherapy (NAC) were included. The sensitivity and specificity of FDG-PET/CT were calculated. We assessed the relationship between the combined results for US-guided FNAC with FDG-PET/CT and the pathological ALN status. RESULTS: A total of 271 patients underwent FDG-PET/CT. Of these patients, 41 underwent US-guided FNAC. The sensitivity and the specificity of FDG-PET/CT for the cases without NAC were 18.5%, 97.1%, respectively. The sensitivity in cases with NAC was 68.2%. As a whole, the sensitivity was 40.8%. ALN metastasis was detected using US-guided FNAC in a case with a negative FDG uptake in the ALN. The T stage was T2 in the case and the FDG uptake at the primary site was poor. CONCLUSION: FDG-PET/CT has a good specificity for ALN metastasis, although its sensitivity is limited, especially in early-stage cases. In cases with a negative FDG uptake in the ALN, US-guided FNAC may play a role in the detection of lymph node metastasis when the primary tumor size is large and the FDG uptake in the primary tumor is low.


Assuntos
Biópsia por Agulha Fina , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Fluordesoxiglucose F18 , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Ultrassonografia Mamária , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila , Biomarcadores Tumorais/análise , Biópsia por Agulha Fina/métodos , Neoplasias da Mama/química , Feminino , Humanos , Metástase Linfática/diagnóstico , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Valor Preditivo dos Testes , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Sensibilidade e Especificidade , Biópsia de Linfonodo Sentinela
4.
Neuroscience ; 214: 181-91, 2012 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-22531377

RESUMO

KIAA2022 has been implicated as a gene responsible for expressing X-linked mental retardation (XLMR) proteins in humans. However, the functional role of KIAA2022 in the human brain remains unclear. Here, we revealed that depletion of Kiaa2022 inhibits neurite outgrowth of PC12 cells, indicating that the gene participates in neurite extension. Thus, we termed Kiaa2022 as an XLMR protein related to neurite extension (Xpn). Using the mouse brain as a model and ontogenetic analysis of Xpn by real-time PCR, we clearly demonstrated that Xpn is expressed transiently during the late embryonic and perinatal stages. In situ hybridization histochemistry further revealed that Xpn-expressing neurons could be categorized ontogenetically into three types. The first type showed transient expression of Xpn during development. The second type maximally expressed Xpn during the late embryonic or perinatal stage. Thereafter, Xpn expression in this type of neuron decreased gradually throughout development. Nevertheless, a significant level of Xpn expression was detected even into adulthood. The third type of neurons initiated expression of Xpn during the embryonic stage, and continued to express the gene throughout the remaining developmental stages. Subsequent immunohistochemical analysis revealed that Xpn was localized to the nucleus and cytoplasm throughout brain development. Our findings indicate that Xpn may participate in neural circuit formation during developmental stages via nuclear and cytoplasmic Xpn. Moreover, disturbances of this neuronal circuit formation may play a role in the pathogenesis of mental retardation.


Assuntos
Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Neuritos/fisiologia , Animais , Encéfalo/metabolismo , Masculino , Deficiência Intelectual Ligada ao Cromossomo X/genética , Deficiência Intelectual Ligada ao Cromossomo X/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neuritos/metabolismo , Células PC12 , Ratos
5.
Kyobu Geka ; 64(5): 394-7, 2011 May.
Artigo em Japonês | MEDLINE | ID: mdl-21591442

RESUMO

We report a case of surgical treatment of pulmonary pleomorphic carcinoma invading the azygos vein. Chest computed tomography (CT) revealed a mass of 6 cm in size, in the upper lobe of the right lung. He underwent the right upper lobectomy and lymph node dissection with combined resection of the involved azygos vein. Histological examination revealed pleomorphic carcinoma (pT3N0M0, stage IIB). The postoperative course was uneventful, and he was alive without recurrence 26 months after the operation. Six cases of pleomorphic carcinoma have been surgically treated between June 2008 and August 2009 in our institute. Early diagnose with complete resection is suggested to be essential in the improvement of survival for this disease based on review of our experience.


Assuntos
Veia Ázigos/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Idoso , Humanos , Masculino , Invasividade Neoplásica
6.
Clin Pharmacol Ther ; 88(6): 809-13, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20980997

RESUMO

Despite the outstanding results generally obtained with imatinib mesylate (IM) in the treatment of chronic myeloid leukemia (CML), some patients show a poor molecular response. To evaluate the relationship between steady-state trough plasma IM concentration (IM-C(min)) and clinical response in CML patients, we integrated data from six independent Japanese studies. Among 254 CML patients, the mean IM-C(min) was 1,010.5 ng/ml. Importantly, IM-C(min) was significantly higher in patients who achieved a major molecular response (MMR) than in those who did not (P = 0.002). Multivariate analysis showed that an MMR was associated with both age (odds ratio (OR) = 0.97 (0.958-0.995); P = 0.0153) and with IM-C(min) (OR = 1.0008 (1.0003-1.0015); P = 0.0044). Given that patients with IM-C(min) values >1,002 ng/ml had a higher probability of achieving an MMR in our large cohort (P = 0.0120), the data suggest that monitoring of IM levels in plasma may improve the efficacy of IM therapy for CML patients.


Assuntos
Povo Asiático , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/metabolismo , Piperazinas/farmacocinética , Piperazinas/uso terapêutico , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Estudos de Coortes , Feminino , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
8.
Eur J Neurol ; 14(4): 464-6, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17389000

RESUMO

We report a novel missense mutation of the Notch3 gene in a Japanese family with CADASIL. The Cys49Gly mutation in this family is located in exon 2 of the Notch3 gene. Most of the documented Notch3 gene mutations occur in exons 3 or 4. On the other hand, there are few reports around the world of mutations in exon 2 of the Notch3 gene, and this is the first report of a mutation in exon 2 of the gene in a Japanese family. In general, CADASIL mutations involve a cysteine residue. Such mutations may influence the tertiary structure of the Notch3 protein, resulting in protein dysfunction. Thus, the CADASIL in the present case may be a consequence of the mutation in exon 2 causing a structural change in the Notch3 protein.


Assuntos
CADASIL/genética , Mutação de Sentido Incorreto , Receptores Notch/genética , Adulto , Povo Asiático , Encéfalo/patologia , CADASIL/diagnóstico , CADASIL/fisiopatologia , Diagnóstico Diferencial , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Doença de Meniere/diagnóstico , Doença de Meniere/genética , Doença de Meniere/patologia , Doença de Meniere/fisiopatologia , Microscopia Eletrônica de Transmissão , Linhagem , Receptor Notch3 , Pele/patologia , Zumbido/fisiopatologia , Vertigem/fisiopatologia
9.
Mol Psychiatry ; 12(4): 398-407, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17389905

RESUMO

Disrupted-in-schizophrenia 1 (DISC1) is a gene disrupted by a (1;11) (q42.1;q14.3) translocation that segregates with major psychiatric disorders in a Scottish family. To investigate how DISC1 confers susceptibility to psychiatric disorders, we previously identified fasciculation and elongation protein zeta-1 and Kendrin as DISC1-interacting molecules in a yeast two-hybrid screen of a human brain complementary DNA library. Here, we have further identified a novel DISC1-interacting protein, termed DISC1-Binding Zinc-finger protein (DBZ), which has a predicted C(2)H(2)-type zinc-finger motif and coiled-coil domains. DBZ was co-immunoprecipitated with DISC1 in lysates of PC12 cells and rat brain tissue. The domain of DISC1 interacting with DBZ was close to the translocation breakpoint in the DISC1 gene. DBZ messenger RNA (mRNA) was expressed in human brains, but not in peripheral tissues. In situ hybridization revealed high expression of DBZ mRNA in the hippocampus, olfactory tubercle, cerebral cortex and striatum in rats. Because this pattern of localization was similar to that of the pituitary adenylate cyclase (PAC(1)) receptor for pituitary adenylate cyclase-activating polypeptide (PACAP), which has recently been implicated in neuropsychological functions, we examined whether DISC1/DBZ interaction was involved in the PACAP signaling pathway. PACAP upregulated DISC1 expression and markedly reduced the association between DISC1 and DBZ in PC12 cells. A DISC1-binding domain of DBZ reduced the neurite length in PC12 cells after PACAP stimulation and in primary cultured hippocampal neurons. The present results provide some new molecular insights into the mechanisms of neuronal development and neuropsychiatric disorders.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Neuritos/fisiologia , Dedos de Zinco/fisiologia , Animais , Encéfalo/citologia , Células Cultivadas , Proteínas de Fluorescência Verde/metabolismo , Humanos , Imuno-Histoquímica , Hibridização In Situ , Proteínas do Tecido Nervoso/genética , Neurônios/citologia , Ligação Proteica , Ratos , Transfecção , Técnicas do Sistema de Duplo-Híbrido
10.
Clin Lab Haematol ; 27(5): 307-11, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16178910

RESUMO

The T cell-lineage marker CD2 is sometimes expressed in acute promyelocytic leukemia (APL), and CD2 expression is reported to correlate with some clinical characteristics. However, the significance of CD2 expression in APL has not been fully elucidated. We evaluated CD2 expression in APL treated by the same treatment strategy in a single institute, and whether it had any special characteristics. Among 29 APL, 6 were positive for CD2. Patients with CD2+ APL tended to have a higher leukocyte count than CD2- APL (34.5 +/- 13.1/l vs. 6.8 +/- 2.1/l), morphological characteristics as variant-APL (50 vs. 0%). They also showed poor clinical prognosis. The CR rate of CD2- APL was 87.0% while that of CD2+ APL was 50 %. The mortality was 13.0 and 66.7%, respectively, and the survival rate was significantly lower in CD2+ APL. CD2 expression was proven to be a risk factor associated with death in addition to the morphological characteristics of variant-APL and leukocytosis. These results indicated that CD2 expression might have a significant impact on the prognosis of APL. Whether CD2+ APL should be characterized as a special clinical entity should be discussed in a larger patient population.


Assuntos
Antígenos CD2/análise , Leucemia Promielocítica Aguda/patologia , Adulto , Antígenos de Neoplasias/análise , Forma Celular , Humanos , Imunofenotipagem , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/mortalidade , Contagem de Leucócitos , Leucocitose/etiologia , Pessoa de Meia-Idade , Prognóstico , Indução de Remissão , Fatores de Risco , Análise de Sobrevida , Linfócitos T
11.
J Food Prot ; 67(11): 2538-43, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15553638

RESUMO

The objective of this study was to investigate the influence of electron-beam and gamma-ray irradiation and temperature (85 to 95 degrees C) on Alicyclobacillus acidoterrestris GD3B strain (NCIMB 13137) spores by calculating and comparing the decimal reduction dose or time (D-values). The survival rate of A. acidoterrestris spores decreased exponentially with irradiation doses of an electron beam or gamma ray. D-values determined for electron-beam and gamma-ray irradiated spores on filter paper ranged from 1.02 to 1.10 kGy. On the other hand, the thermal sterilization effect showed a single exponential decrease within 1.5-log decreases in cell numbers (D85 degrees C = 70.5 min, D90 degrees C = 16.1 min, and D95 degrees C = 5.19 min and z-value [change in temperature required to change the D-value] was 8.83 degrees C), and prolonged heating produced an increase of 10 to 13 times that of the thermal resistance. However, within all time ranges studied (5 to 360 min), a linear decrease in the D-value was observed with an increase in the temperature. A combination of two different methods, irradiation before heating, was appropriate for reducing the duration of the heat treatment required to achieve the inactivation of conidia. Moreover, a necessary radiation dosage for complete inactivation of A. acidoterrestris spores that contaminated dextrin was examined. Dextrin is often used in the juice industry as an augmentor, and it is known to be sometimes contaminated by these spores. The D-values of the spores in dextrin for electron-beam and gamma-ray irradiations were 1.72 and 1.79 kGy, respectively. The doses required for elimination of the spores could be lowered by using irradiation in combination with heat sterilization. When dextrin powder contaminated with 10(4) CFU/g of A. acidoterrestris was preirradiated at 1.0 kGy of electron beam, the citrus juice containing dextrin at a concentration of 10% (wt/vol) was completely sterilized by heating for 20 min at 95 degrees C.


Assuntos
Bebidas/microbiologia , Microbiologia de Alimentos , Bacilos Gram-Positivos Formadores de Endosporo/fisiologia , Temperatura Alta , Citrus/microbiologia , Contagem de Colônia Microbiana , Relação Dose-Resposta à Radiação , Conservação de Alimentos/métodos , Raios gama , Bacilos Gram-Positivos Formadores de Endosporo/crescimento & desenvolvimento , Bacilos Gram-Positivos Formadores de Endosporo/efeitos da radiação , Esporos Bacterianos/crescimento & desenvolvimento , Fatores de Tempo
12.
Apoptosis ; 9(4): 501-8, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15192333

RESUMO

The endoplasmic reticulum (ER) resident-94 kDa glucose-regulated protein (GRP94), plays a pivotal role in cell death due to ER stress. In our study expression of GRP94 was increased in human neuroblastoma SH-SY5Y cells due to exposure to calcium ionophore A23187. A23187-mediated cell death was associated with activation of the major cysteine proteases, caspase-3 and calpain. Pretreatment with adenovirus-mediated antisense GRP94 (AdGRP94AS) reduced viability of SH-SY5Y cells subjected to A23187 treatment compared with wild type cells or cells with adenovirus-mediated overexpression of GRP94 (AdGRP94S). These results indicated that suppression of GRP94 is associated with accelerated cell death. Moreover, expression of GRP94 suppressed A23187-induced cell death and stabilized calcium homeostasis.


Assuntos
Apoptose/fisiologia , Calcimicina/farmacologia , Cálcio/metabolismo , Proteínas de Choque Térmico HSP70/fisiologia , Proteínas de Membrana/fisiologia , Neurônios/fisiologia , Clorometilcetonas de Aminoácidos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Calpaína/antagonistas & inibidores , Calpaína/metabolismo , Caspase 3 , Caspases/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , DNA Antissenso/genética , Dantroleno/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Expressão Gênica/genética , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Histocitoquímica , Homeostase/efeitos dos fármacos , Humanos , Marcação In Situ das Extremidades Cortadas , Óperon Lac/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Tapsigargina/farmacologia , Transfecção
13.
Mol Psychiatry ; 8(7): 685-94, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12874605

RESUMO

Disrupted-In-Schizophrenia 1 (DISC1) was identified as a novel gene disrupted by a (1;11)(q42.1;q14.3) translocation that segregated with schizophrenia in a Scottish family. Predicted DISC1 product has no significant homology to other known proteins. Here, we demonstrated the existence of DISC1 protein and identified fasciculation and elongation protein zeta-1 (FEZ1) as an interacting partner of DISC1 by a yeast two-hybrid study. FEZ1 and its nematode homolog are reported to represent a new protein family involved in axonal outgrowth and fasciculation. In cultured hippocampal neurons, DISC1 and FEZ1 colocalized in growth cones. Interactions of these proteins were associated with F-actin. In the course of neuronal differentiation of PC12 cells, upregulation of DISC1/FEZ1 interaction was observed as along with enhanced extension of neurites by overexpression of DISC1. The present study shows that DISC1 participates in neurite outgrowth through its interaction with FEZ1. Recent studies have provided reliable evidence that schizophrenia is a neurodevelopmental disorder. As there is a high level of DISC1 expression in developing rat brain, dysfunction of DISC1 may confer susceptibility to psychiatric illnesses through abnormal development of the nervous system.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Transporte/fisiologia , Proteínas de Ligação a DNA/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Neuritos/metabolismo , Esquizofrenia/genética , Proteínas Supressoras de Tumor/fisiologia , Actinas/metabolismo , Adulto , Animais , Linhagem Celular/metabolismo , Linhagem Celular/ultraestrutura , Células Cultivadas/metabolismo , Células Cultivadas/ultraestrutura , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Hipocampo/citologia , Humanos , Rim , Substâncias Macromoleculares , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Neurônios/ultraestrutura , Células PC12/citologia , Ligação Proteica , Ratos , Proteínas Recombinantes de Fusão/fisiologia , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/genética , Técnicas do Sistema de Duplo-Híbrido
14.
Cell Death Differ ; 10(6): 698-708, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12761578

RESUMO

The aberrant splicing isoform (PS2V), generated by exon 5 skipping of the Presenilin-2 (PS2) gene transcript, is a diagnostic feature of sporadic Alzheimer's disease (AD). We found PS2V is hypoxia-inducible in human neuroblastoma SK-N-SH cells. We purified a responsible trans-acting factor based on its binding to an exon 5 fragment. The factor was identified as the high mobility group A1a protein (HMGA1a; formerly HMG-I). HMGA1a bound to a specific sequence on exon 5, located upstream of the 5' splice site. HMGA1a expression was induced by hypoxia and the protein was accumulated in the nuclear speckles with the endogenous splicing factor SC35. Overexpression of HMGA1a generated PS2V, but PS2V was repressed by cotransfection with the U1 snRNP 70K protein that has a strong affinity to HMGA1a. HMGA1a could interfere with U1 snRNP binding to the 5' splice site and caused exon 5 skipping. HMGA1a levels were significantly increased in the brain tissue from sporadic AD patients. We propose a novel mechanism of sporadic AD that involves HMGA1a-induced aberrant splicing of PS2 pre-mRNA in the absence of any mutations.


Assuntos
Processamento Alternativo/genética , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Proteína HMGA1a/metabolismo , Proteínas de Membrana/genética , Precursores de RNA/genética , Sequência de Bases/genética , Sítios de Ligação/genética , Éxons/genética , Genes Reguladores/genética , Proteína HMGA1a/genética , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Proteínas de Membrana/biossíntese , Mutação/genética , Presenilina-2 , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , Sítios de Splice de RNA/genética , RNA Nuclear Pequeno/genética
16.
Biochem Biophys Res Commun ; 288(5): 1141-8, 2001 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-11700030

RESUMO

Binding of ATP, but not of ADP, activates Escherichia coli DnaA protein for replicational initiation of the chromosome. To elucidate this switching mechanism, we used the affinity-labeling agent ATP-pyridoxal, which forms a covalent bond with the Lys residue located at or near the gamma-phosphate of ATP. ATP-pyridoxal inhibited the ATP binding for DnaA protein, with a competitive mode. Binding stoichiometry was 0.28 ATP-pyridoxal/DnaA molecule, a value consistent with that of ATP. Thus, ATP-pyridoxal was a potent antagonist for the DnaA ATP-binding site. The labeled DnaA protein was inactive for minichromosome replication in vitro, suggesting that conformation of the region is important for DnaA activity. Isolation of the labeled, tryptic fragment and the Edman degradation revealed that ATP-pyridoxal modified Lys-415. Thus, this residue is likely close to the bound ATP. Since Lys-415 is located in the DNA-binding domain, these findings imply internal interaction between the domains for ATP binding and DNA binding.


Assuntos
Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/metabolismo , Marcadores de Afinidade/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Lisina/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Ligação Competitiva , Replicação do DNA , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Dados de Sequência Molecular , Peptídeos/metabolismo , Conformação Proteica , Estrutura Terciária de Proteína , Tripsina/química
17.
Dev Growth Differ ; 43(5): 583-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11576175

RESUMO

A homolog of the glucosamine-6-phosphate isomerase in the cellular slime mold Dictyostelium discoideum has been analyzed. The gene disruption mutant was arrested at the mound stage, demonstrating that the gene is important for development. The gene was expressed in vegetatively growing cells, silenced on starvation and expressed again in prestalk cells during the multicellular stages. The upstream region of the gene (1376 bp relative to ATG) was cloned and sequenced to study the transcription control mechanisms. Analysis of deletion mutants and a site-directed mutant indicated that the Myb-binding sequence (5'-AACTG-3') localized in the upstream region is important for gene expression. The results of gel-shift assays showed the presence of an Myb-related protein binding to the sequence at the growing phase and another protein binding to the sequence at developmental stages.


Assuntos
Aldose-Cetose Isomerases/biossíntese , Dictyostelium/metabolismo , Proteínas Proto-Oncogênicas c-myb/química , Proteínas Proto-Oncogênicas c-myb/fisiologia , Animais , Sequência de Bases , Sítios de Ligação , Northern Blotting , Núcleo Celular/metabolismo , Células Cultivadas , Eletroporação , Expressão Gênica , Cinética , Modelos Genéticos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Distribuição Tecidual , Transcrição Gênica , beta-Galactosidase/metabolismo
19.
J Biol Chem ; 276(46): 43446-54, 2001 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-11551913

RESUMO

Recent studies have shown independently that presenilin-1 (PS1) null mutants and familial Alzheimer's disease (FAD)-linked mutants should both down-regulate signaling of the unfolded protein response (UPR). However, it is difficult to accept that both mutants possess the same effects on the UPR. Furthermore, contrary to these observations, neither loss of PS1 and PS2 function nor expression of FAD-linked PS1 mutants were reported to have a discernable impact on the UPR. Therefore, re-examination and detailed analyses are needed to clarify the relationship between PS1 function and UPR signaling. Here, we report that PS1/PS2 null and dominant negative PS1 mutants, which are mutated at aspartate residue 257 or 385, did not affect signaling of the UPR. In contrast, FAD-linked PS1 mutants were confirmed to disturb UPR signaling by inhibiting activation of both Ire1alpha and ATF6, both of which are endoplasmic reticulum (ER) stress transducers in the UPR. Furthermore, PS1 mutants also disturbed activation of PERK (PKR-like ER kinase), which plays a crucial role in inhibiting translation during ER stress. Taken together, these observations suggested that PS1 mutations could affect signaling pathways controlled by each of the respective ER-stress transducers, possibly through a gain-of-function.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutação , Estresse Fisiológico , Transdução Genética , Animais , Ácido Aspártico/química , Western Blotting , Regulação para Baixo , Fibroblastos/metabolismo , Genes Dominantes , Humanos , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Plasmídeos/metabolismo , Presenilina-1 , Ligação Proteica , Dobramento de Proteína , Transdução de Sinais , Fatores de Tempo , Transfecção , Células Tumorais Cultivadas
20.
Anticancer Res ; 21(3B): 1879-83, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11497272

RESUMO

Gallic acid, a structural unit of tannin, induced apoptotic cell death, characterized by nuclear condensation and caspase activation in human oral tumor cell lines (HSC-2, HSG). Agarose gel electrophoresis demonstrated that gallic acid produced large DNA fragments in these cells, as well as in T-cell leukemia (MOLT-4) and erythroleukemia (K-562) cells, whereas it induced internucleosomal DNA fragmentation in human myelogenous leukemic cell lines (HL-60, ML-1, U-937, THP-1). This indicates that induction of internucleosomal DNA fragmentation or production of large DNA fragments depends on both target cells and inducers. Addition of total saliva dose-dependently reduced the cytotoxicity induction by gallic acid. These data suggested that the biological action of gallic acid might be modified by physiological fluids.


Assuntos
Antioxidantes/farmacologia , Apoptose , Ácido Gálico/farmacologia , Saliva/metabolismo , Caspases/metabolismo , Núcleo Celular/metabolismo , Fragmentação do DNA , Relação Dose-Resposta a Droga , Eletroforese em Gel de Ágar , Ativação Enzimática/efeitos dos fármacos , Humanos , Modelos Químicos , Células Tumorais Cultivadas
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