Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 487
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Gene Ther ; 24(11): 706-716, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28820502

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with a median survival of 3-4 years after diagnosis. It is the most frequent form of a group of interstitial pneumonias of unknown etiology. Current available therapies prevent deterioration of lung function but no therapy has shown to improve survival. Periostin is a matricellular protein of the fasciclin 1 family. There is increased deposition of periostin in lung fibrotic tissues. Here we evaluated whether small interfering RNA or antisense oligonucleotide against periostin inhibits lung fibrosis by direct administration into the lung by intranasal route. Pulmonary fibrosis was induced with bleomycin and RNA therapeutics was administered during both acute and chronic phases of the disease. The levels of periostin and transforming growth factor-ß1 in airway fluid and lung tissue, the deposition of collagen in lung tissue and the lung fibrosis score were significantly reduced in mice treated with siRNA and antisense against periostin compared to control mice. These findings suggest that direct administration of siRNA or antisense oligonucleotides against periostin into the lungs is a promising alternative therapeutic approach for the management of pulmonary fibrosis.


Assuntos
Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/fisiologia , Fibrose Pulmonar/terapia , Administração Intranasal/métodos , Animais , Bleomicina/farmacologia , Colágeno/análise , Feminino , Fibroblastos/metabolismo , Fibrose , Fibrose Pulmonar Idiopática/genética , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/terapia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Oligonucleotídeos , Oligonucleotídeos Antissenso/metabolismo , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/farmacologia , Fator de Crescimento Transformador beta/análise
2.
Phys Rev Lett ; 117(16): 162501, 2016 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-27792367

RESUMO

In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from ^{67}Kr. At the same time, no evidence for 2p emission of ^{59}Ge and ^{63}Se, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to ^{67}Kr as being the best new candidate among the three for two-proton radioactivity. ^{67}Kr is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of ^{67}Kr is 7.4(30) ms.

3.
Allergol Immunopathol (Madr) ; 44(3): 191-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26774356

RESUMO

BACKGROUND: Bronchial asthma is characterised by airway inflammation and remodelling with a decline of lung function. Fibrocytes are bone marrow-derived mesenchymal progenitor cells that play important roles in the pathogenesis of airway remodelling. Several clinical parameters are currently being used in routine clinical practice to assess outcome of therapy in asthma including frequency of rescue with short-acting ß2-agonist and the asthma control test. In this study, we hypothesised that asthma control test is associated with circulating levels of fibrocytes in bronchial asthma. METHODS: There were 20 patients with asthma and seven healthy controls. The number of CD45(+)Collagen I(+) circulating fibrocytes was assessed in the peripheral blood by flow cytometry. RESULTS: The number of circulating fibrocytes was significantly increased in asthma patients with moderate and severe disease compared to controls, and it was inversely correlated with % forced expiratory volume in one second and % forced vital capacity (%FVC). The frequency of inhalation of short-acting ß2 agonist and the asthma control test score was significantly and inversely correlated with the number of circulating fibrocytes. CONCLUSION: The results of this study showed that the number of circulating fibrocytes is inversely correlated with clinical asthma control parameters, further supporting the relevance of measuring circulating fibrocytes as a marker of clinical control in bronchial asthma.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Asma/sangue , Biomarcadores/sangue , Inflamação/sangue , Células-Tronco Mesenquimais/imunologia , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Adulto , Idoso , Asma/tratamento farmacológico , Colágeno Tipo I/metabolismo , Feminino , Citometria de Fluxo , Humanos , Japão , Antígenos Comuns de Leucócito/metabolismo , Masculino , Células-Tronco Mesenquimais/metabolismo , Pessoa de Meia-Idade , Testes de Função Respiratória , Inquéritos e Questionários , Resultado do Tratamento
5.
J Oral Rehabil ; 41(9): 667-74, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24841831

RESUMO

This research was designed to investigate the acoustic characteristics of voluntary expiratory sounds after swallow for detecting dysphagia. Forty-nine patients with complaints of swallow difficulty received a videofluorographic (VF) examination. They were divided into three groups: nine who did not have any apparent disease (Group N), 22 patients with head and neck cancer (Group H&N) and 18 patients with other diseases including cerebrovascular disease (Group OD). After liquid barium swallows, they exhaled voluntarily without voicing. Videofluorographic findings were classified into four groups: normal (Normal), acceptable swallow (Acceptable), swallow with residue (Resid) and swallows with penetration or aspiration (Pen/Asp). The duration of expiratory sounds was measured on the time waveform. Frequency characteristics of expiratory sounds were obtained using one-third octave band analysis ranging from 62·5 to 2000·0 Hz of central frequency. The averaged level of the 1000·0-Hz band was chosen as the reference band level (RB level). The revised averaged level of each band was obtained by subtracting the RB level from the averaged level of each band. Zero decibel of the revised magnitude of the 125·0-Hz band was set as the critical value to differentiate dysphagia (Resid or Pen/Asp) from no dysphagia (Normal or Acceptable). Comparison of this assessment with VF findings showed a significant percentage agreement (85·4%). These results suggest that frequency characteristics of post-swallow expiratory sounds can differentiate dysphagia from no dysphagia among multiple dysphagic patient groups.


Assuntos
Transtornos de Deglutição/diagnóstico , Deglutição/fisiologia , Expiração/fisiologia , Som , Idoso , Idoso de 80 Anos ou mais , Compostos de Bário , Feminino , Fluoroscopia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Gravação em Vídeo/métodos
6.
Radiologia (Engl Ed) ; 66(2): 107-113, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38614527

RESUMO

INTRODUCTION AND OBJECTIVES: To compare gonad doses with and without a gonad protector and to optimize the use of gonadal protectors in infants thorax radiography. MATERIALS AND METHODS: Two pediatric anthropomorphic phantoms are used: an X-ray system for KXO-50SS/DRX-3724HD, and a digital radiography system for CALNEO Smart C12, with and without a gonad protector during infants thorax radiography. A real time skin dosimeter is placed on the X-ray system, and a real time skin dosimeter is inserted on the front side of the mammary gland, the front and back sides of the true pelvis level, and on the ovaries and testes. The X-ray system is irradiated 15 times using phantoms with and without a gonad protector. The measured entrance patient doses values of for the real time skin dosimeter are compared for each phantom, with and without the gonad protector. RESULTS: The medium of measured entrance patient doses values for front side dose of the true pelvis level with and without the protector are 10.00 and 5.00 µGy at newborn, and 10.00 and 0.00µGy at one year, respectively. The medium of measured entrance patient doses values for the back side dose of the true pelvis level with and without the protector are 0.00 and 0.00 µGy at both newborn one year, respectively. The measured entrance patient doses cannot be detected in the ovaries and testes with or without the protector. No significant differences are observed in the measured entrance patient doses values for the front and back side doses of the pelvis, ovaries, and testes at newborn and one year, with and without the protector (p>0.05). CONCLUSIONS: No significant difference was observed in gonad dose measurements with and without the gonad protector during infants chest radiography. We believe that gonadal protector wearing is not necessary.


Assuntos
Gônadas , Lactente , Recém-Nascido , Humanos , Criança , Radiografia
7.
Br J Cancer ; 109(7): 1760-5, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24002604

RESUMO

BACKGROUND: Radical hysterectomy is recommended for endometrial adenocarcinoma patients with suspected gross cervical involvement. However, the efficacy of operative procedure has not been confirmed. METHODS: The patients with endometrial adenocarcinoma who had suspected gross cervical involvement and underwent hysterectomy between 1995 and 2009 at seven institutions were retrospectively analysed (Gynecologic Oncology Trial and Investigation Consortium of North Kanto: GOTIC-005). Primary endpoint was overall survival, and secondary endpoints were progression-free survival and adverse effects. RESULTS: A total of 300 patients who underwent primary surgery were identified: 74 cases with radical hysterectomy (RH), 112 patients with modified radical hysterectomy (mRH), and 114 cases with simple hysterectomy (SH). Median age was 47 years, and median duration of follow-up was 47 months. There were no significant differences of age, performance status, body mass index, stage distribution, and adjuvant therapy among three groups. Multi-regression analysis revealed that age, grade, peritoneal cytology status, and lymph node involvement were identified as prognostic factors for OS; however, type of hysterectomy was not selected as independent prognostic factor for local recurrence-free survival, PFS, and OS. Additionally, patients treated with RH had longer operative time, higher rates of blood transfusion and severe urinary tract dysfunction. CONCLUSION: Type of hysterectomy was not identified as a prognostic factor in endometrial cancer patients with suspected gross cervical involvement. Perioperative and late adverse events were more frequent in patients treated with RH. The present study could not find any survival benefit from RH for endometrial cancer patients with suspected gross cervical involvement. Surgical treatment in these patients should be further evaluated in prospective clinical studies.


Assuntos
Adenocarcinoma/mortalidade , Adenocarcinoma/cirurgia , Neoplasias do Endométrio/cirurgia , Histerectomia , Neoplasias do Colo do Útero/cirurgia , Índice de Massa Corporal , Colo do Útero/cirurgia , Intervalo Livre de Doença , Neoplasias do Endométrio/mortalidade , Feminino , Humanos , Histerectomia/efeitos adversos , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Neoplasias do Colo do Útero/mortalidade
9.
Diabet Med ; 29(7): e41-6, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22248365

RESUMO

AIMS: Dehydroepiandrosterone exerts a protective effect against cardiovascular diseases. However, the relationship of dehydroepiandrosterone with the anticoagulant factor activated protein C, generated by the thrombin-thrombomodulin complex on vascular endothelial cells, remains unknown. This study aimed at studying the relationship between dehydroepiandrosterone and activated protein C generation in patients with Type 2 diabetes. METHODS: Sixty-two male patients with Type 2 diabetes were enrolled in this study. Data obtained from 40 healthy male subjects were used as controls. The plasma levels of dehydroepiandrosterone, the activated protein C-protein C inhibitor complex, high-sensitivity C-reactive protein and monocyte chemoattractant protein-1 were measured by enzyme immunoassays. Carotid intima-media thickness was measured by ultrasonography. RESULTS: The plasma levels of dehydroepiandrosterone (5.15 ± 2.81 vs. 3.76 ± 2.16 ng/ml; P < 0.005) and the activated protein C-protein C inhibitor complex (1.90 ± 1.07 vs. 1.02 ± 0.51 ng/ml; P < 0.001) were significantly lower in patients with diabetes than in normal subjects. Univariate analysis showed a significant correlation of the plasma level of dehydroepiandrosterone with that of the activated protein C-protein C inhibitor complex (r = 0.48, P < 0.001), high-sensitivity C-reactive protein (r = -0.30, P < 0.05) and with the mean intima-media thickness (r = -0.28, P < 0.05) in patients with diabetes. Stepwise multiple regression analysis showed that the plasma level of dehydroepiandrosterone is significantly correlated with the plasma levels of the activated protein C-protein C inhibitor complex (F = 18.06) and high-sensitivity C-reactive protein (F = 4.94). There was no correlation between the plasma levels of dehydroepiandrosterone and monocyte chemoattractant protein-1. CONCLUSIONS: These results suggest that lower circulating levels of dehydroepiandrosterone are associated with decreased activated protein C generation and higher intima-media thickness in patients with Type 2 diabetes.


Assuntos
Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/sangue , Espessura Intima-Media Carotídea , Desidroepiandrosterona/sangue , Diabetes Mellitus Tipo 2/sangue , Angiopatias Diabéticas/sangue , Proteína C/biossíntese , Adulto , Idoso , Biomarcadores/sangue , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteína C/metabolismo
10.
Br J Dermatol ; 166(6): 1319-26, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22293026

RESUMO

BACKGROUND: Debate on how to manage paediatric patients with cutaneous melanoma continues, particularly in those with sentinel lymph node (SLN) metastases who are at higher risk of poor outcomes. Management is often based on adult algorithms, although differences in clinical outcomes between paediatric and adult patients suggest that melanoma in paediatric patients differs biologically. Yet, there are no molecular prognostic studies identifying these differences. OBJECTIVES: We investigated the epigenetic (methylation) regulation of several tumour-related genes (TRGs) known to be significant in adult melanoma progression in histopathology(+) SLN metastases (n = 17) and primary tumours (n = 20) of paediatric patients with melanoma to determine their clinical relevance. METHODS: Paediatric patients (n = 37; ≤ 21 years at diagnosis) with American Joint Committee on Cancer stage I-III cutaneous melanoma were analysed. Gene promoter methylation of the TRGs RASSF1A, RARß2, WIF1 and APC was evaluated. RESULTS: Hypermethylation of RASSF1A, RARß2, WIF1 and APC was found in 29% (5/17), 25% (4/16), 25% (4/16) and 19% (3/16) of histopathology(+) SLNs, respectively. When matched to adult cutaneous melanomas by Breslow thickness and ulceration, hypermethylation of all four TRGs in SLN(+) paediatric patients with melanoma was equivalent to or less than in adults. With a median follow-up of 55 months, SLN(+) paediatric patients with melanoma with hypermethylation of > 1 TRG vs. ≤ 1 TRG had worse disease-free (P = 0·02) and overall survival (P = 0·02). CONCLUSIONS: Differences in the methylation status of these TRGs in SLN(+) paediatric and adult patients with melanoma may account for why SLN(+) paediatric patients have different clinical outcomes. SLN biopsy should continue to be performed; within SLN(+) paediatric patients with melanoma, hypermethylation of TRGs can be used to identify a subpopulation at highest risk for poor outcomes who warrant vigilant clinical follow-up.


Assuntos
Metilação de DNA/fisiologia , Genes Neoplásicos/genética , Melanoma/metabolismo , Neoplasias Cutâneas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteína da Polipose Adenomatosa do Colo/metabolismo , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Metástase Linfática , Masculino , Melanoma/genética , Receptores do Ácido Retinoico/metabolismo , Proteínas Repressoras/metabolismo , Neoplasias Cutâneas/genética , Proteínas Supressoras de Tumor , Adulto Jovem
12.
Eur J Neurol ; 18(7): 1006-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20727007

RESUMO

BACKGROUND AND PURPOSE: Life style-related disorders such as hypertension, diabetes, dyslipidemia, and obesity are reported to be a great risk of dementia. Adipocytokines released from adipose tissue are thought to modulate some brain functions including memory and cognition. We here analysed adiponectin, one of the most important adipocytokines, in plasma and cerebrospinal fluid (CSF) from cognitive normal controls (NC), mild cognitive impairment (MCI) subjects, and patients with Alzheimer's disease (AD) and discussed if/how adiponectin could relate to the pathogenesis of AD. METHODS: Normal controls (n = 28), MCI (n = 18), and AD (n = 27) subjects were recruited at Tohoku University Hospital. The diagnosis of AD was based on NINCDS-ADRDA criteria. All the blood and CSF samples were obtained from each fasted subject. Adiponectin was assayed using a sandwich ELISA system. RESULTS: The levels of adiponectin between in plasma and in CSF showed a positive correlation. Plasma adiponectin was significantly higher in MCI and AD compared to NC, whereas CSF adiponectin was significantly higher in MCI compared to NC. CONCLUSION: It is possible that the level of adiponectin in plasma reflects its level in CSF. The tendency to have higher adiponectin in plasma and CSF from MCI and AD suggests that this molecule plays a critical role in the onset of AD.


Assuntos
Adiponectina/sangue , Adiponectina/líquido cefalorraquidiano , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Transtornos Cognitivos/sangue , Transtornos Cognitivos/líquido cefalorraquidiano , Idoso , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Testes Neuropsicológicos
14.
Gen Comp Endocrinol ; 167(1): 135-42, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20138183

RESUMO

The responses of Mozambique and Nile tilapia acclimated to fresh water (FW) and brackish water (BW; 17 per thousand) were compared following acute salinity challenges. In both species, plasma osmolality increased to above 450 mOsm by 2h after transfer from FW to seawater (SW); these increases in osmolality were accompanied by unexpected increases in plasma prolactin (PRL). Likewise, PRL receptor gene expression in the gill also increased in both species. In Nile tilapia, hyperosmotic transfers (FW to BW and SW) resulted in increased plasma growth hormone (GH) and in branchial GH receptor gene expression, responses that were absent in Mozambique tilapia. Branchial gene expression of osmotic stress transcription factor 1 (OSTF1) increased in both species following transfer from FW to SW, whereas transfer from BW to SW induced OSTF1 expression only in the Nile tilapia. Branchial expression of Na(+)/Cl(-) cotransporter was higher in FW in both species than in BW. Branchial gene expression of Na(+)/K(+)/2Cl(-) cotransporter (NKCC) increased after transfer from BW to SW in Mozambique tilapia, whereas expression was reduced in the Nile tilapia following the same transfer. The difference in the SW adaptability of these species may be related to a limited capacity of Nile tilapia to up-regulate NKCC gene expression, which is likely to be an essential component in the recruitment of SW-type chloride cells. The differential responses of GH and OSTF1 may also be associated with the disparate SW adaptability of these two tilapiine species.


Assuntos
Ciclídeos/sangue , Proteínas de Peixes/genética , Regulação da Expressão Gênica , Hormônio do Crescimento/sangue , Prolactina/sangue , Salinidade , Tilápia/sangue , Animais , Peptídeos e Proteínas de Sinalização Intracelular , Peptídeos/genética , Reação em Cadeia da Polimerase , Receptores da Prolactina/genética , Receptores da Somatotropina/genética
15.
Science ; 368(6486): 67-71, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32193363

RESUMO

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

16.
J Viral Hepat ; 16(10): 716-23, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19302338

RESUMO

Retinol-binding protein 4 (RBP4) is a recently identified adipokine that is elevated in the blood in several insulin-resistant states. We investigated the association between plasma RBP4 and histological and biochemical characteristics of chronic hepatitis C (CHC), as well as changes in RBP4 levels following interferon therapy. Eighty-one patients with CHC infected with genotype 1 received treatment with peginterferon plus ribavirin. Histological data were available for 41 out of 81 patients before treatment, and the degree of fibrosis, inflammation and steatosis was assessed. Plasma levels of RBP4 were determined in serial samples (before, at the end of treatment, and at 6 months post-treatment). RBP4 levels were lower in CHC patients than in control subjects (34.6 +/- 12.3 microg/mL vs 46.2 +/- 10.5 microg/mL; P

Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Proteínas Plasmáticas de Ligação ao Retinol/análise , Idoso , Fígado Gorduroso/patologia , Feminino , Genótipo , Hepacivirus/classificação , Hepacivirus/isolamento & purificação , Hepatite C Crônica/patologia , Humanos , Interferon alfa-2 , Fígado/patologia , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Plasma/química , Proteínas Recombinantes , Ribavirina/uso terapêutico , Índice de Gravidade de Doença , Carga Viral
17.
Hum Reprod ; 24(5): 1045-50, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19189994

RESUMO

Infertility patients are known to be at increased risk of endometrial carcinoma (EC) and atypical hyperplasia (AH). However, the incidence and clinical features of EC and AH in these patients remain to be clarified. In this study, we examined the rate at which a routine infertility workup revealed EC/AH and investigated the clinicopathological features of EC/AH detected in this way. Among patients diagnosed with EC or AH at the Jichi Medical University Hospital between the 10-year period from 1997 to 2006, six patients were referred from Tochigi Central Clinic, a specialized infertility facility. We report the clinicopathological features of these patients and calculate the incidence of EC/AH in patients who underwent infertility investigations at Tochigi Central Clinic. All six patients were younger than 40 and had early stage disease (final diagnosis: EC stage IA: 3, EC stage IB: 1, AH: 2). A total of 19 826 patients underwent routine infertility investigations at Tochigi Central Clinic during the same period. The incidence of EC/AH detected from these investigations was 0.03% (6/19 826) and that of EC was 0.02% (4/19 826): 5-10 times higher than the overall incidence in Japanese women of the same age. Routine infertility investigations may provide an opportunity to examine the corpus uteri of young women in whom examination is otherwise limited, contributing to the early detection of EC/AH.


Assuntos
Hiperplasia Endometrial/epidemiologia , Neoplasias do Endométrio/epidemiologia , Infertilidade Feminina/complicações , Adulto , Hiperplasia Endometrial/complicações , Hiperplasia Endometrial/diagnóstico , Neoplasias do Endométrio/complicações , Neoplasias do Endométrio/diagnóstico , Feminino , Humanos , Incidência , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
J Cell Biol ; 150(5): 989-1000, 2000 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-10973990

RESUMO

Tau and MAP1B are the main members of neuronal microtubule-associated proteins (MAPs), the functions of which have remained obscure because of a putative functional redundancy (Harada, A., K. Oguchi, S. Okabe, J. Kuno, S. Terada, T. Ohshima, R. Sato-Yoshitake, Y. Takei, T. Noda, and N. Hirokawa. 1994. Nature. 369:488-491; Takei, Y., S. Kondo, A. Harada, S. Inomata, T. Noda, and N. Hirokawa. 1997. J. Cell Biol. 137:1615-1626). To unmask the role of these proteins, we generated double-knockout mice with disrupted tau and map1b genes and compared their phenotypes with those of single-knockout mice. In the analysis of mice with a genetic background of predominantly C57Bl/6J, a hypoplastic commissural axon tract and disorganized neuronal layering were observed in the brains of the tau+/+map1b-/- mice. These phenotypes are markedly more severe in tau-/-map1b-/- double mutants, indicating that tau and MAP1B act in a synergistic fashion. Primary cultures of hippocampal neurons from tau-/-map1b-/- mice showed inhibited axonal elongation. In these cells, a generation of new axons via bundling of microtubules at the neck of the growth cones appeared to be disturbed. Cultured cerebellar neurons from tau-/-map1b-/- mice showed delayed neuronal migration concomitant with suppressed neurite elongation. These findings indicate the cooperative functions of tau and MAP1B in vivo in axonal elongation and neuronal migration as regulators of microtubule organization.


Assuntos
Axônios/fisiologia , Proteínas Associadas aos Microtúbulos/fisiologia , Neurônios/fisiologia , Proteínas tau/fisiologia , Envelhecimento , Animais , Axônios/ultraestrutura , Encéfalo/anormalidades , Encéfalo/crescimento & desenvolvimento , Movimento Celular , Células Cultivadas , Cerebelo/citologia , Cerebelo/fisiologia , Genótipo , Hipocampo/citologia , Hipocampo/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes Neurológicos , Proteínas Associadas aos Microtúbulos/deficiência , Proteínas Associadas aos Microtúbulos/genética , Morfogênese , Neurônios/citologia , Fenótipo , Proteínas tau/deficiência , Proteínas tau/genética
19.
J Cell Biol ; 145(5): 1039-48, 1999 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-10352020

RESUMO

Deletion of the synapsin I genes, encoding one of the major groups of proteins on synaptic vesicles, in mice causes late onset epileptic seizures and enhanced experimental temporal lobe epilepsy. However, mice lacking synapsin I maintain normal excitatory synaptic transmission and modulation but for an enhancement of paired-pulse facilitation. To elucidate the cellular basis for epilepsy in mutants, we examined whether the inhibitory synapses in the hippocampus from mutant mice are intact by electrophysiological and morphological means. In the cultured hippocampal synapses from mutant mice, repeated application of a hypertonic solution significantly suppressed the subsequent transmitter release, associated with an accelerated vesicle replenishing time at the inhibitory synapses, compared with the excitatory synapses. In the mutants, morphologically identifiable synaptic vesicles failed to accumulate after application of a hypertonic solution at the inhibitory preterminals but not at the excitatory preterminals. In the CA3 pyramidal cells in hippocampal slices from mutant mice, inhibitory postsynaptic currents evoked by direct electrical stimulation of the interneuron in the striatum oriens were characterized by reduced quantal content compared with those in wild type. We conclude that synapsin I contributes to the anchoring of synaptic vesicles, thereby minimizing transmitter depletion at the inhibitory synapses. This may explain, at least in part, the epileptic seizures occurring in the synapsin I mutant mice.


Assuntos
Epilepsia/genética , Deleção de Genes , Hipocampo/fisiologia , Sinapsinas/genética , Transmissão Sináptica/fisiologia , Animais , Eletrofisiologia , Epilepsia/fisiopatologia , Potenciais Evocados , Camundongos , Microscopia Imunoeletrônica , Vesículas Sinápticas/fisiologia , Vesículas Sinápticas/ultraestrutura
20.
J Cell Biol ; 137(7): 1615-26, 1997 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-9199175

RESUMO

Microtubule-associated protein 1B (MAP1B), one of the microtubule-associated proteins (MAPs), is a major component of the neuronal cytoskeleton. It is expressed at high levels in immature neurons during growth of their axons, which indicates that it plays a crucial role in neuronal morphogenesis and neurite extension. To better define the role of MAP1B in vivo, we have used gene targeting to disrupt the murine MAP1B gene. Heterozygotes of our MAP1B disruption exhibit no overt abnormalities in their development and behavior, while homozygotes showed a slightly decreased brain weight and delayed nervous system development. Our data indicate that while MAP1B is not essential for survival, it is essential for normal time course development of the murine nervous system. These conclusions are very different from those of a previous MAP1B gene-targeting study (Edelmann, W., M. Zervas, P. Costello, L. Roback, I. Fischer, A. Hammarback, N. Cowan, P. Davis, B. Wainer, and R. Kucherlapati. 1996. Proc. Natl. Acad. Sci. USA. 93: 1270-1275). In this previous effort, homozygotes died before reaching 8-d embryos, while heterozygotes showed severely abnormal phenotypes in their nervous systems. Because the gene targeting event in these mice produced a gene encoding a 571-amino acid truncated product of MAP1B, it seems likely that the phenotypes seen arise from the truncated MAP1B product acting in a dominant-negative fashion, rather than a loss of MAP1B function.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Proteínas Associadas aos Microtúbulos/genética , Sistema Nervoso/embriologia , Animais , Deleção de Genes , Marcação de Genes , Homozigoto , Camundongos , Camundongos Mutantes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA