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1.
Eur J Gynaecol Oncol ; 35(1): 11-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24654454

RESUMO

PURPOSE: To review the outcome in patients with atypical endometrial hyperplasia (AEH) and endometrial cancer (EC) who received MPA treatment in the present hospital. MATERIALS AND METHODS: Patients with AEH or EC were administered MPA for 12 weeks followed by endometrial curettage. The rates of effect, recurrence, pregnancy, and complications were evaluated. The changes in progesterone receptors and FOXO-1, known as a target of MPA treatment, were examined by immunostaining. RESULTS: Four of seven patients with endometrial cancer and three of three patients with AH had complete response. Four of seven patients had recurred within one year after the treatment and had to undergo hysterectomy. None of the patients showed changes in progesterone receptors. Although six of seven patients were negative for FOXO-1 before and after treatment, all the patients showed increased developments of FOXO-1 during MPA treatment. CONCLUSION: Progestin as a fertility-preserving treatment is expected to be effective for endometrial cancer, but judicious use might be required because it shows high rate of recurrence. Further studies regarding the mechanism may be necessary to achieve high efficacy.


Assuntos
Hiperplasia Endometrial/tratamento farmacológico , Neoplasias do Endométrio/tratamento farmacológico , Preservação da Fertilidade/métodos , Acetato de Medroxiprogesterona/uso terapêutico , Tratamentos com Preservação do Órgão/métodos , Adulto , Hiperplasia Endometrial/metabolismo , Neoplasias do Endométrio/metabolismo , Feminino , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/análise , Fatores de Transcrição Forkhead/química , Fatores de Transcrição Forkhead/metabolismo , Humanos , Imuno-Histoquímica , Japão , Receptores de Progesterona/análise , Receptores de Progesterona/química , Receptores de Progesterona/metabolismo , Resultado do Tratamento
2.
Eur J Gynaecol Oncol ; 35(1): 48-51, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24654461

RESUMO

PURPOSE: Primary prophylaxis with G-CSF has been used to minimize myelosuppression caused by anticancer agents and to avoid severe neutropenia. The authors retrospectively examined the value of primary prophylaxis using granulocyte colony-stimulating factor (G-CSF) for epithelial ovarian cancer. MATERIALS AND METHODS: From 2001 to 2010, 105 patients with ovarian cancer receiving chemotherapy in the present hospital were divided into two groups: one received primary prophylaxis with G-CSF and the other did not receive it in compliance with the guidelines for G-CSF usage. The incidence of febrile neutropenia (FN), degree of neutropenia, frequency of G-CSF administration, number of days of hospitalization, progression-free survival (PFS), and overall survival (OS) were evaluated. RESULTS: Neutrophils decreased almost equally and the length of hospitalization was not significantly lower between the groups. Five-year PFS or OS showed no significant difference either. CONCLUSIONS: Primary prophylaxis with G-CSF in chemotherapy for epithelial ovarian cancer could be of low significance.


Assuntos
Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Fatores Imunológicos/uso terapêutico , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Antibioticoprofilaxia , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Carcinoma Epitelial do Ovário , Neutropenia Febril Induzida por Quimioterapia/etiologia , Neutropenia Febril Induzida por Quimioterapia/prevenção & controle , Feminino , Humanos , Incidência , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
Eur J Gynaecol Oncol ; 32(3): 325-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21797126

RESUMO

Lymphoepithelioma-like carcinoma (LELC) of the uterine cervix is a rare variant of squamous cell carcinoma of the uterine cervix. This tumor is characterized by nests of poorly differentiated epithelial cells surrounded by a prominent lymphocytic infiltration. Despite the poorly differentiated pathological findings, it appears to have a better outcome than the usual squamous cell carcinoma of the uterine cervix. Therefore, it is quite important to differentiate this tumor from poorly differentiated squamous cell carcinoma and lympho-proliferative disorders of the cervix. LELC arising from the nasopharynx has been suggested to be associated with Epstein-Barr virus (EBV), whereas the involvement of EBV in LELC of the uterine cervix is still controversial. In addition, the role of high-risk human papilloma virus (HPV) in this type of tumor remains unknown. We report a case of LELC of the cervix with diagnosis on the basis of histopathology in a 52-year-old Japanese woman who presented with a history of continuous bleeding post menopause. We also examine the association of EBV and HPV in this case.


Assuntos
Carcinoma de Células Escamosas/patologia , Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Carcinoma de Células Escamosas/virologia , Colo do Útero/virologia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae , Neoplasias do Colo do Útero/virologia
4.
Biochim Biophys Acta ; 1131(2): 161-5, 1992 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-1610896

RESUMO

We have cloned a cDNA encoding Luciola lateralis (a common firefly in Japan) luciferase from a cDNA library of lantern poly(A)+ RNA, using a cDNA of L. cruciata (another common firefly in Japan) luciferase as a probe. The primary structure of L. lateralis luciferase deduced from the nucleotide sequence was shown to consist of 548 amino acids with a molecular weight of 60,132. Sequence comparison indicates that L. lateralis luciferase has significant sequence identity (94%) to L. cruciata luciferase, and that it has less sequence similarity (67%) to Photinus pyralis (a North American firefly) luciferase. The isolated cDNA clone, when introduced into Escherichia coli, directed the synthesis of enzymatically active luciferase under the control of the lacZ promoter.


Assuntos
Besouros/genética , Escherichia coli/genética , Luciferases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Códon , DNA/isolamento & purificação , Expressão Gênica , Luciferases/metabolismo , Dados de Sequência Molecular , Mapeamento por Restrição , Alinhamento de Sequência
5.
Biochim Biophys Acta ; 1120(2): 228-32, 1992 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-1562591

RESUMO

Luciferases of Luciola cruciata and Luciola lateralis, LcL and LlL, were purified to homogeneity by ammonium sulfate precipitation, gel-filtration column chromatography, and hydroxyapatite HPLC. The molecular masses of the enzymes determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were both 62 kDa, almost identical to that of Photinus pyralis (PpL). LcL was found to be similar to PpL in thermal stability, pH stability, and the wavelength of maximum light intensity. LlL was superior to LcL and PpL in thermal and pH stability, and the reaction catalyzed by LlL emits green light with a peak intensity at 552 nm, which is 10 nm shorter in wavelength than those of PpL and LcL.


Assuntos
Besouros/enzimologia , Luciferases/isolamento & purificação , Animais , Eletroforese em Gel de Poliacrilamida , Temperatura Alta , Concentração de Íons de Hidrogênio , Luciferases/química , Medições Luminescentes , Peso Molecular , Análise Espectral
6.
Biochim Biophys Acta ; 1431(2): 363-73, 1999 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-10350612

RESUMO

Various thermophilic bacteria were analyzed by Southern hybridization analysis using oligonucleotide probes coding for the pyruvate phosphate dikinase (PPDK) gene from Clostridium symbiosum, and positive hybridization signals were observed in the chromosomal DNAs from Microbispora rosea subsp. aerata (IFO 14047). PPDK activity was detected in lactose induced cells and the enzyme was purified to homogeneity. The molecular mass of PPDK was estimated to be 230000 by gel filtration chromatography and 91000 by SDS-PAGE, suggesting that PPDK is a dimeric enzyme. This enzyme was specific for adenine nucleotide and the apparent Km values for AMP, PPi, and phosphoenolpyruvate were 5, 38, and 280 microM, respectively. It was stable in the pH range 6 to 11, and retained 80% activity after 60 min heat treatment at 60 degrees C. We cloned the PPDK gene from M. rosea. It consists of 878 amino acids with a molecular mass of 95514. Sequence comparison indicates around 50% similarity with other PPDKs and it has all the highly conserved regions of the related enzymes. We expressed the PPDK gene in Escherichia coli and obtained enzymatically active protein.


Assuntos
Actinomyces/enzimologia , Piruvato Ortofosfato Diquinase/isolamento & purificação , Sequência de Aminoácidos , Sequência de Bases , Southern Blotting , Cromatografia em Gel , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Escherichia coli/enzimologia , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Piruvato Ortofosfato Diquinase/biossíntese , Piruvato Ortofosfato Diquinase/genética , Temperatura
7.
Biochim Biophys Acta ; 1208(1): 179-85, 1994 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-8086433

RESUMO

The neutral proteinase II from Aspergillus oryzae (NpII) is a zinc proteinase with three intramolecular disulfide bonds. NpII is most unstable after 10 min at about 75 degrees C, but regains stability beyond this temperature and is relatively stable at 100 degrees C. We analyzed the thermal stability of wild-type NpII and apo NpII. The results suggested that NpII unfolds reversibly upon incubation up to 100 degrees C, and that the irreversible inactivation observed is mainly due to autoproteolysis. To further understand the stability, a mutant NpII (Cys78-->Ala) lacking one of the disulfide bonds, was produced in a heterologous yeast expression system. The mutant NpII showed a similar stability profile, but the most unstable temperature and the most catalytically active temperature decreased to the same extent (around 10 degrees C), confirming that autoproteolysis is the main cause of the irreversible inactivation. Several lines of evidence presented in this study demonstrated that the thermal stability of o++NpII is attributed to reversible thermal unfolding and autoproteolysis.


Assuntos
Aspergillus oryzae/enzimologia , Temperatura Alta , Metaloendopeptidases/metabolismo , Sequência de Bases , DNA Complementar/genética , Dissulfetos/metabolismo , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Técnicas de Transferência de Genes , Metaloendopeptidases/química , Metaloendopeptidases/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Plasmídeos , Dobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Relação Estrutura-Atividade
8.
Biochim Biophys Acta ; 960(1): 19-25, 1988 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-3358944

RESUMO

The incorporation of exogenous fatty acid into lipids of liver and liver nuclei of rats fed diets with or without fat was compared. When [3H]palmitic acid was injected into rats, more radioactivity was incorporated into triacylglycerols and phospholipids of liver and liver nuclei from rats fed the fat-free diet than from those fed the fat diet. The results were supported further by an autoradiographic study. On the other hand, the enzyme induction and quantity of malic enzyme mRNA were decreased by fat feeding. Other lipogenic enzymes were also coordinately decreased. Thus, it may be possible that exogenous fatty acid is involved in nuclear regulation in addition to cytosolic regulation of lipogenic enzyme induction.


Assuntos
Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos , Fígado/enzimologia , Animais , Núcleo Celular/metabolismo , Citosol/enzimologia , Gorduras na Dieta/farmacologia , Indução Enzimática/efeitos dos fármacos , Fígado/metabolismo , Malato Desidrogenase/biossíntese , Malato Desidrogenase/genética , Masculino , Ácido Palmítico , Ácidos Palmíticos/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos , Transcrição Gênica/efeitos dos fármacos
9.
Diabetes ; 44(7): 733-8, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7540572

RESUMO

Nitric oxide (NO) is believed to be an effector molecule that mediates interleukin (IL)-1 beta-induced destruction and dysfunction of pancreatic beta-cells. We have demonstrated that both exogenous NO and NO generated endogenously by IL-1 beta brought about apoptosis of isolated rat pancreatic islet cells as well as pancreatic beta-cell tumor-derived cell line HIT. This apoptosis was characterized by cleavage of DNA into nucleosomal fragments of 180-200 bp and morphologically by nuclear shrinkage, chromatic condensation, and apoptotic body formation. The IL-1 beta-induced internucleosomal DNA cleavage occurred in a time- and dose-dependent manner. Actinomycin D, cycloheximide, and nitric oxide synthase inhibitors inhibited the DNA cleavage, which was correlated with the amount of NO produced, indicating that NO produced by HIT cells themselves could mediate the apoptosis. Furthermore, in the presence of tumor necrosis factor (TNF)-alpha, large amounts of NO were produced by IL-1 beta and DNA cleavage occurred more noticeably, although TNF-alpha alone did not generate NO. Streptozotocin (STZ), a diabetogenic reagent containing a nitroso moiety, also released NO and induced internucleosomal DNA cleavage in HIT cells. These results suggest that NO-induced internucleosomal DNA cleavage is an important initial step in the destruction and dysfunction of pancreatic beta-cells induced by inflammatory stimulation or treatment with STZ.


Assuntos
Aminoácido Oxirredutases/biossíntese , Apoptose/efeitos dos fármacos , Expressão Gênica , Interleucina-1/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Penicilamina/análogos & derivados , Animais , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cicloeximida/farmacologia , DNA/efeitos dos fármacos , DNA/isolamento & purificação , DNA/metabolismo , Dactinomicina/farmacologia , Eletroforese em Gel de Ágar , Humanos , Insulinoma , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/ultraestrutura , Cinética , Microscopia Eletrônica de Varredura , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase , Nucleossomos/efeitos dos fármacos , Nucleossomos/metabolismo , Neoplasias Pancreáticas , Penicilamina/farmacologia , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , S-Nitroso-N-Acetilpenicilamina , Fatores de Tempo , Células Tumorais Cultivadas
10.
J Mol Biol ; 182(2): 191-203, 1985 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-3889347

RESUMO

The nucleotide sequence of a 6251 base-pair plasmid, pSR1, harbored in an osmophilic haploid yeast, Zygosaccharomyces rouxii (formerly Saccharomyces rouxii), was determined. No homology was detected between the sequences of pSR1 and 2-micron DNA of Saccharomyces cerevisiae. pSR1 has a pair of inverted repeats consisting of completely homologous 959 base-pair sequences, which separate two unique sequences 2654 base-pairs and 1679 base-pairs long. Each inverted repeat has an ARS sequence functional in both Z. rouxii and S. cerevisiae hosts. Short direct repeats or dyad symmetries were observed in the inverted repeats similar to those found close to the replication origin of 2-micron DNA. Three open reading frames, P, S and R, each able to encode a protein of molecular weight larger than 10,000, were found. Insertional inactivation of R gave rise to a defect in the intramolecular recombination at the inverted repeats, and that of S reduced the copy number of pSR1 in the S. cerevisiae host. The maintenance stability of the plasmid was also tested in the heterogeneous S. cerevisiae host, but the results of the insertional inactivation of P, S and R were ambiguous. pSR1 and 2-micron DNA were compatible in S. cerevisiae cells, but the protein factors encoded by these plasmids did not complement each other.


Assuntos
Plasmídeos , Saccharomyces/genética , Sequência de Bases , Códon , DNA Circular , DNA Fúngico , DNA Recombinante , Sequências Repetitivas de Ácido Nucleico , Saccharomyces cerevisiae/genética , Transformação Genética
11.
Gene ; 77(2): 265-70, 1989 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-2473944

RESUMO

Luciferases of Japanese and North American fireflies act on a common substrate (luciferin) but the resulting lights emitted are of different colors. As a step toward an understanding of the molecular mechanism of the luciferase reaction, a cDNA clone (pGLf1) was isolated from a cDNA library of lantern poly(A)+RNA of the Japanese firefly, Luciola cruciata ('Genji-botaru' in Japanese), using a cDNA of North American firefly luciferase. The isolated 2-kb cDNA sequence was able to direct the synthesis of active luciferase in Escherichia coli under the control of the lac promoter. The primary structure of Genji firefly luciferase deduced from the nucleotide sequence was shown to consist of 548 amino acids (aa) with an Mr of 60,024. Homology between the amino acid sequences of the Genji and North American firefly luciferases was 67%, but a number of amino acid changes were found in the first 200 aa from the N terminus.


Assuntos
Clonagem Molecular , Besouros/genética , DNA/genética , Luciferases/genética , RNA/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Besouros/enzimologia , Escherichia coli/genética , Luciferases/metabolismo , Dados de Sequência Molecular , Plasmídeos , Poli A/isolamento & purificação , Especificidade da Espécie
12.
Neuroscience ; 58(3): 553-61, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7513387

RESUMO

Neurons were acutely dissociated from the rat nucleus basalis, and membrane currents (whole-cell patch-clamp) and intracellular free Ca2+ concentrations (Fura-2) were measured simultaneously from large neurons (approximately 25 microns in diameter). A brief depolarization from -60 to 0 mV for 200 ms evoked an increase in intracellular free calcium and a slow outward tail current (72 +/- 8 pA, n = 30). The outward current reversed polarity at -75.5 +/- 2.7 mV (n = 14). The tail current declined and the intracellular calcium recovered its resting level exponentially with time-constants of 1.0 +/- 0.1 s and 2.5 +/- 0.2 s, respectively (n = 17). In neurons loaded with Cs-gluconate, a similar depolarizing pulse evoked a similar increase in intracellular free calcium, but this was now followed by an inward tail current (118 +/- 8 pA, n = 44). The inward tail current reversed polarity at -27.8 +/- 3.8 mV (n = 7), and was suppressed by removal of external sodium ions. Neither outward nor inward tail currents were observed, when the external solution was calcium-free or when the pipette solution contained EGTA (10 mM). These results indicate that a depolarization causes a calcium entry and that this consequently increases both K+ conductance and non-selective cation conductance.


Assuntos
Gânglios da Base/metabolismo , Cálcio/fisiologia , Canais Iônicos/fisiologia , Neurônios/metabolismo , Canais de Potássio/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Gânglios da Base/citologia , Gânglios da Base/efeitos dos fármacos , Césio/farmacologia , Fura-2 , Técnicas In Vitro , Canais Iônicos/efeitos dos fármacos , Canais Iônicos/metabolismo , Cinética , Neurônios/efeitos dos fármacos , Canais de Potássio/efeitos dos fármacos , Canais de Potássio/metabolismo , Ratos , Ratos Wistar , Sódio/metabolismo , Espectrometria de Fluorescência
13.
Neuroscience ; 92(3): 855-65, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10426527

RESUMO

Evoked release of acetylcholine and subsequent cell-cell adhesive contacts between growth cones and acetylcholine sensing neurons were observed using cultured neurons dissociated from the diagonal band of Broca of the rat. Stimulation to the soma of the diagonal band of Broca neurons evoked release of acetylcholine from the growth cones. The release of acetylcholine was monitored using whole-cell patch-clamp recording from acetylcholine receptor-rich superior cervical ganglion neuron positioned on the growth cone as a sensor of acetylcholine release. By measuring changes in fluorescence from the growth cone using Ca2(+)-sensitive dye while voltage-clamping the superior cervical ganglion neuron, transient intracellular Ca2+ concentration increase and acetylcholine release from growth cone were recorded simultaneously. Video-enhanced differential interference contrast imaging of the growth cones demonstrated tether formation between the growth cone and superior cervical ganglion cell soma when the superior cervical ganglion cell soma was moved away from the growth cone after acetylcholine release, suggesting formation of adhesive contacts between the growth cone and the sensor neuron. Adhesive contacts between growth cones and sensor neurons were also detected when a high K+ solution or alpha-latrotoxin was applied to the growth cone. Adhesions were also observed between growth cones and latex beads, when growth cones were exposed to high K+ solution. The properties of the adhesive contacts at the growth cone were studied by optically manipulating a latex bead attached to the growth cone surface. These results suggest that growth cones exhibit cell-cell adhesion after neurotransmitter release.


Assuntos
Comunicação Celular/fisiologia , Cones de Crescimento/fisiologia , Neurotransmissores/metabolismo , Animais , Cálcio/metabolismo , Adesão Celular/fisiologia , Estimulação Elétrica , Lobo Frontal/fisiologia , Cones de Crescimento/metabolismo , Técnicas In Vitro , Líquido Intracelular/metabolismo , Lasers , Microesferas , Neurônios/fisiologia , Concentração Osmolar , Ratos , Ratos Wistar , Gânglio Cervical Superior/citologia , Gânglio Cervical Superior/fisiologia
14.
Neuroscience ; 97(2): 347-55, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10799766

RESUMO

We developed an experimental system to investigate mechanosensitivity of a single neuron, using cultured rat dorsal root ganglion cells. Highly precise mechanical stimulation was applied to various sites of the cells, using a piezo-driven glass microcapillary whose movement was computer-controlled, while whole-cell patch-clamp recordings were made from the cell bodies. When the growth cones and lamillipodia from the cell soma were mechanically stimulated, inward currents were recorded at the holding potential of -60mV. Filopodia were most sensitive to mechanical stimulation. However, when neurites or soma of dorsal root ganglion cells were stimulated in the same way, electrical responses were hardly recorded. Two types of currents varying in time-course were observed: fast type of 100-200ms and slow type of several seconds in duration. When the membrane potential was held at around 0mV, both types of currents were almost abolished or even reversed, and the reversal potential was estimated to be about -2. 2mV. Replacement of extracellular sodium by tetraethylammonium did not significantly change the reversal potential. In the low-chloride solution ([Cl(-)](o)=11.7mM), the reversal potential was about +60mV, as expected from the Nernst equation for chloride. These inward currents were almost completely inhibited by extracellular application of chloride channel blocker, 5-nitro-2-(3-phenylpropylamino) benzoic acid (100microM). These results indicate that the inward currents are due to activation of mechanosensitive chloride channels, preferentially located on the growth cones of cultured dorsal root ganglion neurons.


Assuntos
Canais de Cloreto/fisiologia , Gânglios Espinais/fisiologia , Neurônios/fisiologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Canais de Cloreto/efeitos dos fármacos , Gânglios Espinais/citologia , Potenciais da Membrana , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Neuritos/ultraestrutura , Neurônios/citologia , Técnicas de Patch-Clamp , Estimulação Física , Pseudópodes/fisiologia , Ratos , Ratos Wistar , Sódio/farmacologia , Tetraetilamônio/farmacologia , Tetrodotoxina/farmacologia
15.
Neuroscience ; 77(4): 1187-99, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9130797

RESUMO

Growing neurites of rat dorsal root ganglion neurons in culture formed growth cones at the tips. Possible release of glutamate from these growth cones was investigated by using a whole-cell patch-clamp recording from an acutely dissociated hippocampal neuron containing glutamate receptors. The hippocampal neuron was placed in contact to various regions of the dorsal root ganglion neurons. Inward currents were recorded from the hippocampal neuron positioned on the growth cones of the dorsal root ganglion neurons (diameter, 12-16 microm) in response to the dorsal root ganglion cell body stimulation. The inward currents were associated with an increase in membrane conductance, and the reversal potential was estimated at -6.5 mV (n=8). The inward currents were blocked by 6-cyano-7-nitroquinoxaline (10 microM), but not blocked by 2-amino-5-phosphonovaleric acid (50 microM) and bicuculline (10 microM). The inward currents were abolished by tetrodotoxin (1 microM), EGTA-buffered Ca2+-free external solution or omega-agatoxin IVA (300 nM), and were inhibited by omega-conotoxin GVIA (3 microM), but were not affected by nicardipine (10 microM). Intracellular calcium ion concentration ([Ca2+]i) in growth cones of the dorsal root ganglion neurons increased in response to dorsal root ganglion cell body stimulation, whereas the elevation of [Ca2+]i was not observed either in the presence of tetrodotoxin (1 microM) or in a Ca2+-free external solution. These results indicate that the inward currents were evoked by glutamate released from the growth cones via a Ca2+-dependent process, and suggest that the growth cones are already endowed with much of the machinery for neurotransmitter release, even before making a structure for synaptic transmission.


Assuntos
Gânglios Espinais/citologia , Ácido Glutâmico/metabolismo , Neurônios/metabolismo , Neurotransmissores/metabolismo , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Cálcio/metabolismo , Células Cultivadas , Quelantes/farmacologia , Ácido Egtázico/farmacologia , Eletrofisiologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/citologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Ratos , Ratos Wistar , Tetrodotoxina/farmacologia
16.
Neuroscience ; 120(4): 993-1003, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12927205

RESUMO

Signal transmission from a chick hair cell to the growth cone of a vestibular ganglion cell was examined by placing an acutely dissociated hair cell on the growth cone of a cultured vestibular ganglion cell. Electrical stimuli were applied to the hair cell while monitoring the intracellular Ca(2+) concentration ([Ca(2+)](i)) at the growth cone or recording whole-cell currents from the vestibular ganglion cell. Electrical stimulation of the hair cell induced [Ca(2+)](i) increases at the growth cone and inward currents in the vestibular ganglion cell. The [Ca(2+)](i) increase was blocked by 6-cyano-7-nitroquinoxaline (CNQX) (10 microM) but not by 2-amino-5-phosphonovaleric acid (APV; 50 microM). Glutamate (100 nM-300 microM) applied to the vestibular ganglion cell by the Y-tube method induced inward currents which were also antagonized by CNQX, but not by APV. These results indicate that the electrical stimulation of a hair cell induced glutamate or glutamate like agent release from the hair cell, which activated non-N-methyl-D-aspartate receptors at the growth cone of the vestibular ganglion cell, followed by action potentials and [Ca(2+)](i) elevation in the vestibular ganglion cell. This is the first demonstration of in vitro reconstitution of functional signal transmission from a hair cell to a vestibular ganglion cell.


Assuntos
Fura-2/análogos & derivados , Gânglios Sensitivos/fisiologia , Cones de Crescimento/fisiologia , Células Ciliadas Vestibulares/fisiologia , Transdução de Sinais/fisiologia , Valina/análogos & derivados , Vestíbulo do Labirinto/fisiologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Células Cultivadas , Embrião de Galinha , Relação Dose-Resposta a Droga , Estimulação Elétrica , Potenciais Evocados/efeitos dos fármacos , Potenciais Evocados/fisiologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Fura-2/metabolismo , Gânglios Sensitivos/citologia , Gânglios Sensitivos/efeitos dos fármacos , Gânglios Sensitivos/metabolismo , Ácido Glutâmico/farmacologia , Cones de Crescimento/efeitos dos fármacos , Cones de Crescimento/metabolismo , Células Ciliadas Vestibulares/efeitos dos fármacos , Células Ciliadas Vestibulares/metabolismo , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Imuno-Histoquímica , Técnicas In Vitro , Condução Nervosa/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Receptores de AMPA/metabolismo , Fatores de Tempo , Valina/farmacologia , Vestíbulo do Labirinto/citologia , Vestíbulo do Labirinto/efeitos dos fármacos , Vestíbulo do Labirinto/metabolismo
17.
J Histochem Cytochem ; 40(8): 1157-63, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1619279

RESUMO

The distribution of rat manganese superoxide dismutase (Mn-SOD) was immunohistochemically investigated in the rat stomach with a specific polyclonal antibody and a labeled streptavidin-biotin immunoglobulin detection system in cryosections. Parietal cells in the stomach were intensely stained, whereas the other epithelial cells in the gastric gland and pit exhibited only slight staining. Rapid-freezing and freeze-substitution immunoelectron microscopy revealed that Mn-SOD in parietal cells was mainly localized in mitochondria. Therefore, the large amount of Mn-SOD in parietal cells is due to the abundant mitochondria, in which Mn-SOD is considered to play important roles in protecting the ion pump and the cell itself from superoxide insult. Application of Triton X-100, cryosectioning, and the streptavidin-biotin system are needed to distinctly visualize Mn-SOD with our antibody. Treatment of the cryosections with Triton X-100 enhanced not only the immunoreactivity but also the false-positive staining, which showed a similar distribution pattern to that of Mn-SOD and thus made it difficult to determine the localization. The most plausible cause of the false-positive staining is thought to be endogenous biotin in the stomach, which survives paraformaldehyde fixation and is revealed by Triton X-100 treatment. Suppression of the endogenous streptavidin binding activity is important when cryosections, the streptavidin-biotin system, and Triton X-100 are employed.


Assuntos
Mucosa Gástrica/enzimologia , Células Parietais Gástricas/enzimologia , Estômago/enzimologia , Superóxido Dismutase/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Reações Falso-Positivas , Técnicas Imunoenzimáticas , Masculino , Microscopia Imunoeletrônica , Mitocôndrias/enzimologia , Octoxinol , Células Parietais Gástricas/ultraestrutura , Polietilenoglicóis/farmacologia , Ratos , Ratos Endogâmicos , Estreptavidina , Superóxido Dismutase/imunologia
18.
J Biochem ; 80(1): 177-86, 1976 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-965363

RESUMO

Based on criteria such as the ADP/O ratio and respiratory control by ADP, the energy-coupling efficiency of brown adipose tissue mitochondria isolated from rats kept under normal environmental conditions for a long time decreased remarkably. The presence of bovine serum albumin, GTP, or ATP plus carnitine in the reaction medium markedly increased the efficiency of oxidative phosphorylation of brown adipose tissue mitochondria. Pre-treatment of brown adipose tissue mitochondria with 2% bovine serum albumin, GTP, or ATP plus carnitine caused a decrease in the amount of free fatty acids bound to the mitochondria from 13.1 to 7.0, 9.0, or 8.2 mug per mg protein, respectively. Removal of the free fatty acids by means of these pre-treatments resulted in restoration of efficient oxidative phosphorylation; there was a correlation between the amount of free fatty acids removed and the degree of recovery in the respiratory control ratio. The elimination of only a fraction of the free fatty acids, as little as 4 mug per mg protein, was sufficient to ensure respiratory control by ADP. It appears that the free fatty acids which lie mainly outside the inner mitochondrial membrane are responsible for the decrease in the efficiency of oxidative phosphorylation in brown adipose tissue mitochondria isolated from rats kept under normal environmental conditions.


Assuntos
Tecido Adiposo Marrom/metabolismo , Mitocôndrias/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Carnitina/farmacologia , Ácidos Graxos não Esterificados/metabolismo , Feminino , Guanosina Trifosfato/farmacologia , Ácidos Cetoglutáricos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Fosforilação Oxidativa , Consumo de Oxigênio , Ratos , Soroalbumina Bovina/farmacologia
19.
J Biochem ; 115(3): 602-7, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7520037

RESUMO

Nitric oxide synthase (NOS) has been purified over 6,500-fold with a 3.4% yield from rat colorectum with 2',5'-ADP-Sepharose, DEAE cellulose, and gel filtration. The purified enzyme gave a single band corresponding to an apparent molecular mass of 160 Dka on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. When assayed in the requisite presence of L-arginine, CaCl2, NADPH, calmodulin, tetrahydro-L-biopterin, and FAD, the purified enzyme exhibited a specific activity of 328 nmol/min/mg L-citrulline formed and an apparent Km for L-arginine of 2.9 microM. Amino acid sequencing of 12 peptides revealed identical sequences to that of the neuronal type enzyme except for two altered amino acid residues. When partial reverse transcription-polymerase chain reaction of RNA from rat colorectum and cerebellum was performed using primers designed according to the amino acid sequences determined, these amino acid changes were found in both cDNA fragments, indicating the identity of the colorectal enzyme to the cerebellar one. A polyclonal antibody raised against NOS purified from rat cerebellum cross-reacted with the NOS from colorectum but not that from IFN-gamma stimulated macrophage-derived cells, RAW 264.7. Immunohistochemical analysis of the colorectum using this specific antibody indicated that Auerbach's plexus is strongly immunoreactive, supporting the hypothesis that NO is an inhibitory transmitter for non-adrenergic and non-cholinergic nerves in the colorectum.


Assuntos
Aminoácido Oxirredutases/isolamento & purificação , Colo/enzimologia , Reto/enzimologia , Aminoácido Oxirredutases/química , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Cromatografia de Afinidade , Cromatografia em Gel , Clonagem Molecular , DNA Complementar/química , DNA Complementar/metabolismo , Feminino , Imuno-Histoquímica , Dados de Sequência Molecular , Peso Molecular , Óxido Nítrico Sintase , Reação em Cadeia da Polimerase , Ratos , Ratos Wistar , Transcrição Gênica
20.
J Biochem ; 122(6): 1260-4, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9498574

RESUMO

Human vascular endothelial cells play a pivotal role in atherosclerotic changes but are resistant to apoptotic inducers such as Fas ligand and it has been difficult to induce apoptosis. We developed an experimental model for the apoptosis in the endothelial cells by using snake venom treatment. Snake venom was found to generate intracellular reactive oxygen species (ROS) in the endothelial cells, which leads to apoptosis as judged by electron microscopy as well as by DNA cleavage. Buthionine sulfoximine (BSO) and diethyldithiocarbamate (DDC) accelerated the apoptosis, indicating intracellular glutathione and superoxide levels play a critical role. Pretreatment with tumor necrosis factor (TNF) or phorbol ester (TPA), which increases the Mn-SOD level, prevented the apoptosis. These data suggest that intracellular ROS enhances apoptosis whereas several anti-oxidants are protective in human endothelial cells. The induction of apoptosis by ROS of endothelial cells may be related to initiation of atherosclerotic changes.


Assuntos
Antídotos/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Venenos de Crotalídeos/toxicidade , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Glutationa/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/farmacologia , Animais , Butionina Sulfoximina/farmacologia , Células Cultivadas , Quelantes/farmacologia , Venenos de Crotalídeos/metabolismo , Ditiocarb/farmacologia , Endotélio Vascular/metabolismo , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Sequestradores de Radicais Livres/farmacologia , Humanos , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
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