Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 522
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Int J Cosmet Sci ; 40(4): 425-428, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29897105

RESUMO

OBJECTIVE: The major causes of unpleasant human body odour are aldehydes produced by axillary-resident bacteria. There are many methods of body odour prevention; however, they all carry risks of destroying indigenous dermal bacteria that are necessary for the maintenance of the normal physical function of the skin. Furthermore, some methods cannot directly reduce the concentrations of substances that cause body odour. Therefore, a novel method of reducing body odour more safely and effectively is required. We focused on acetic acid bacterial enzymes, which can convert aldehydes into carboxylic acids, and investigated their effect on aldehydes and body odour. METHODS: Subjects with strong body odour were recruited using screening questionnaires. Acetic acid bacterial extract including enzymes was applied to subjects' skin, and their effects were evaluated by trained panellists and by quantitative aldehyde analysis using thermal detector gas chromatography/mass spectrometry. RESULTS: Acetic acid bacterial extract including enzymes decreased the ratio of dilution to threshold and the concentration of body odour-producing aldehydes dropped by up to 98.7%. CONCLUSION: These results indicate that simply applying acetic acid bacterial enzymes on the skin can reduce the concentration of aldehydes that cause unpleasant body odour by directly converting them into carboxylic acids. Therefore, acetic acid bacterial enzymes can potentially be developed into new products that do not destroy indigenous bacteria and yet can effectively reduce unpleasant body odour.


Assuntos
Ácido Acético/metabolismo , Álcool Desidrogenase/metabolismo , Aldeído Desidrogenase/metabolismo , Aldeídos/metabolismo , Bactérias/metabolismo , Odorantes , Pele/microbiologia , Adulto , Bactérias/enzimologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Oxirredução
2.
Nat Genet ; 28(2): 131-8, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11381259

RESUMO

Hypoxia stimulates angiogenesis through the binding of hypoxia-inducible factors to the hypoxia-response element in the vascular endothelial growth factor (Vegf) promotor. Here, we report that deletion of the hypoxia-response element in the Vegf promotor reduced hypoxic Vegf expression in the spinal cord and caused adult-onset progressive motor neuron degeneration, reminiscent of amyotrophic lateral sclerosis. The neurodegeneration seemed to be due to reduced neural vascular perfusion. In addition, Vegf165 promoted survival of motor neurons during hypoxia through binding to Vegf receptor 2 and neuropilin 1. Acute ischemia is known to cause nonselective neuronal death. Our results indicate that chronic vascular insufficiency and, possibly, insufficient Vegf-dependent neuroprotection lead to the select degeneration of motor neurons.


Assuntos
Hipóxia Celular/genética , Fatores de Crescimento Endotelial/genética , Linfocinas/genética , Neurônios Motores/patologia , Degeneração Neural/genética , Elementos de Resposta/genética , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Animais , Axônios/fisiologia , Sítios de Ligação , Eletrofisiologia , Fatores de Crescimento Endotelial/metabolismo , Humanos , Linfocinas/metabolismo , Camundongos , Camundongos Knockout , Neurônios Motores/fisiologia , Contração Muscular , Fibras Musculares Esqueléticas/patologia , Atrofia Muscular/genética , Atrofia Muscular/patologia , Degeneração Neural/patologia , Degeneração Neural/fisiopatologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuropilina-1 , Nervos Periféricos/patologia , Regiões Promotoras Genéticas , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Fatores de Crescimento/genética , Receptores de Fatores de Crescimento/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular , Deleção de Sequência , Medula Espinal/fisiologia , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
3.
Minim Invasive Neurosurg ; 53(2): 86-90, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20533142

RESUMO

INTRODUCTION: A new technique using a navigation system to minimize the influence of brain shift and to perform precise resection of brain tumors is demonstrated. To determine the resection plane, one to six tubes were inserted around the tumor under the guidance of a navigation system before dural incision. RESULTS: This technique termed the "navigation-guided fence-post tube" (NGFP) procedure was used to treat 34 patients with intraaxial brain tumors including gliomas (23 cases), malignant lymphomas (4 cases) and metastatic tumors (7 cases). Tumors were removed totally in 23 cases (67.6%), subtotally (95% or more removal) in 6 cases (17.6%) and partially (less than 95% removal) in 5 cases (14.7%). The cases with subtotal or partial resection contained tumors that were close to or involved the eloquent area, or disseminated lesions. No complications due to tube insertion occurred. CONCLUSION: NGFP is a useful and safe technique for brain tumor surgery with no influence of brain shift during tumor resection.


Assuntos
Neoplasias Encefálicas/cirurgia , Glioma/cirurgia , Neuronavegação/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
J Cell Biol ; 148(6): 1283-93, 2000 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-10725340

RESUMO

Neuropilin-1 is a type 1 membrane protein with three distinct functions. First, it can mediate cell adhesion via a heterophilic molecular interaction. Second, in neuronal cells, neuropilin-1 binds the class 3 semaphorins, which are neuronal chemorepellents, and plays a role in the directional guidance of axons. Neuropilin-1 is expected to form complexes with the plexinA subfamily members and mediate the semaphorin-elicited inhibitory signals into neurons. Third, in endothelial cells, neuropilin-1 binds a potent endothelial cell mitogen, vascular endothelial growth factor (VEGF)(165), and regulates vessel formation. Though the binding sites in neuropilin-1 for the class 3 semaphorins and VEGF(165) have been analyzed, the sites involved in cell adhesion activity of the molecule have not been identified. In this study, we produced a variety of mutant neuropilin-1s and tested their cell adhesion activity. We showed that the b1 and b2 domains within the extracellular segment of neuropilin-1 were required for the cell adhesion activity, and peptides with an 18-amino acid stretch in the b1 and b2 domains were sufficient to induce the cell adhesion activity. In addition, we demonstrated that the cell adhesion ligands for neuropilin-1 were proteins and distributed in embryonic mesenchymal cells but distinct from the class 3 semaphorins, VEGF, or plexins.


Assuntos
Adesão Celular , Fatores de Crescimento Endotelial/metabolismo , Linfocinas/metabolismo , Fatores de Crescimento Neural/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/fisiologia , Células 3T3 , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células COS , Agregação Celular , Linhagem Celular , Galinhas , Sequência Conservada , Fatores de Crescimento Endotelial/farmacologia , Humanos , Células KB , Células L , Linfocinas/farmacologia , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/fisiologia , Camundongos , Dados de Sequência Molecular , Fatores de Crescimento Neural/farmacologia , Proteínas do Tecido Nervoso/genética , Neuropilina-1 , Ratos , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transfecção , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Xenopus
5.
Neuron ; 9(1): 151-61, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1632969

RESUMO

The B2 molecule is a 220 kd neuronal cell surface protein of Xenopus, recognized by monoclonal antibody B2 (MAb B2). Immunohistochemistry using MAb B2 revealed that the B2 molecule was expressed in both the inner and outer plexiform layers within the neural retina. During development of the neural retina, the B2 molecule first appeared at stages 35/36 in the newly formed plexiform layers. When embryonic eyes were cultured in the presence of anti-B2 antiserum (Fab fragments), the formation of the retinal plexiform layers was impeded. These data suggest that the cell surface molecule B2 plays a role in the development of retinal plexiform layers.


Assuntos
Moléculas de Adesão Celular/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Neurônios/citologia , Retina/embriologia , Animais , Anticorpos Monoclonais , Moléculas de Adesão Celular/análise , Moléculas de Adesão Celular/imunologia , Diferenciação Celular/fisiologia , Membrana Celular/química , Membrana Celular/ultraestrutura , Células Cultivadas , Fragmentos Fab das Imunoglobulinas , Imuno-Histoquímica , Microscopia Imunoeletrônica , Proteínas do Tecido Nervoso/análise , Proteínas do Tecido Nervoso/imunologia , Neurônios/química , Neurônios/ultraestrutura , Técnicas de Cultura de Órgãos , Retina/química , Retina/citologia , Xenopus
6.
Neuron ; 7(2): 295-307, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1908252

RESUMO

The A5 antigen is a neuronal cell surface protein of Xenopus presumed to be involved in the neuronal recognition between the optic nerve fibers and the visual centers. Analyses of cDNA clones revealed that the A5 antigen is a class I membrane protein containing two different internal repeats in the extracellular segment. The first repeat bears homology to domain III of complement components C1r and C1s, and the second repeat is homologous to the C1 and C2 domains of coagulation factors V and VIII. The mRNA for the A5 antigen was present in retinal ganglion cells and visual center neurons. Nonneuronal cells in the peripheral and central nervous systems did not express the mRNA for the A5 antigen.


Assuntos
Antígenos de Superfície/genética , Fatores de Coagulação Sanguínea/genética , Proteínas do Sistema Complemento/genética , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Homologia de Sequência do Ácido Nucleico , Sequência de Aminoácidos , Animais , Antígenos de Superfície/imunologia , Antígenos de Superfície/metabolismo , Sequência de Bases , Northern Blotting , Clonagem Molecular , Fator V/genética , Fator V/metabolismo , Fator VIII/genética , Fator VIII/metabolismo , Imunofluorescência , Soros Imunes/imunologia , Imuno-Histoquímica , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/imunologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/ultraestrutura , Neuropilina-1 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Xenopus
7.
Neuron ; 19(3): 519-30, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9331345

RESUMO

The molecules of the collapsin/semaphorin gene family have been thought to play an essential role in axon guidance during development. Semaphorin III/D is a member of this family, has been shown to repel dorsal root ganglion (DRG) axons in vitro, and has been implicated in the patterning of sensory afferents in the spinal cord. Although semaphorin III/D mRNA is expressed in a wide variety of neural and nonneural tissues in vivo, the role played by semaphorin III/D in regions other than the spinal cord is not known. Here, we show that mice homozygous for a targeted mutation in semaphorin III/D show severe abnormality in peripheral nerve projection. This abnormality is seen in the trigeminal, facial, vagus, accessory, and glossopharyngeal nerves but not in the oculomotor nerve. These results suggest that semaphorin III/D functions as a selective repellent in vivo.


Assuntos
Glicoproteínas/genética , Fatores de Crescimento Neural/genética , Sistema Nervoso Periférico/anormalidades , Sistema Nervoso Periférico/embriologia , Vias Aferentes , Animais , Axônios/fisiologia , Embrião de Galinha , Quimera , Olho/embriologia , Olho/inervação , Face/embriologia , Face/inervação , Nervo Facial/anormalidades , Nervo Facial/embriologia , Galactosídeos , Gânglios Espinais/citologia , Gânglios Espinais/embriologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Nervo Glossofaríngeo/anormalidades , Nervo Glossofaríngeo/embriologia , Glicoproteínas/deficiência , Homozigoto , Indóis , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutagênese/fisiologia , Fatores de Crescimento Neural/deficiência , Nervo Oculomotor/embriologia , Semaforina-3A , Nervos Espinhais/embriologia , Coloração e Rotulagem , Nervo Trigêmeo/anormalidades , Nervo Trigêmeo/embriologia , Nervo Vago/anormalidades , Nervo Vago/embriologia
8.
Neuron ; 14(6): 1189-99, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7605632

RESUMO

Plexin (previously referred to as B2) is a neuronal cell surface molecule that has been identified in Xenopus. cDNA cloning reveals that plexin has no homology to known neuronal cell surface molecules but possesses, in its extracellular segment, three internal repeats of cysteine clusters that are homologous to the cysteine-rich domain of the c-met proto-oncogene protein product. The exogenous plexin proteins expressed on the surfaces of L cells by cDNA transfection mediate cell adhesion via a homophilic binding mechanism, under the presence of calcium ions. Plexin is expressed in the receptors and neurons of particular sensory systems. These findings indicate that plexin is a novel calcium-dependent cell adhesion molecule and suggest its involvement in specific neuronal cell interaction and/or contact.


Assuntos
Cálcio/farmacologia , Moléculas de Adesão Celular/metabolismo , Adesão Celular/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Sequência de Aminoácidos , Animais , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Membrana Celular/metabolismo , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Células L , Camundongos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Nariz/inervação , Bulbo Olfatório/metabolismo , Proteínas Proto-Oncogênicas c-met , Receptores Proteína Tirosina Quinases/química , Homologia de Sequência , Transfecção , Vestíbulo do Labirinto/metabolismo , Xenopus
9.
Neuron ; 19(5): 995-1005, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9390514

RESUMO

Neuropilin is a neuronal cell surface protein and has been shown to function as a receptor for a secreted protein, semaphorin III/D, that can induce neuronal growth cone collapse and repulsion of neurites in vitro. The roles of neuropilin in vivo, however, are unknown. Here, we report that neuropilin-deficient mutant mice produced by targeted disruption of the neuropilin gene show severe abnormalities in the trajectory of efferent fibers of the PNS. We also describe that neuropilin-deprived dorsal root ganglion neurons are perfectly protected from growth cone collapse elicited by semaphorin III/D. Our results indicate that neuropilin-semaphorin III/D-mediated chemorepulsive signals play a major role in guidance of PNS efferents.


Assuntos
Glicoproteínas/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Nervos Periféricos/fisiologia , Transdução de Sinais/fisiologia , Transmissão Sináptica/fisiologia , Animais , Encéfalo/fisiologia , Nervos Cranianos/fisiologia , Extremidades/inervação , Gânglios Espinais/fisiologia , Camundongos , Camundongos Endogâmicos ICR , Dados de Sequência Molecular , Mutação , Fibras Nervosas/fisiologia , Proteínas do Tecido Nervoso/genética , Fenômenos Fisiológicos do Sistema Nervoso , Neuropilina-1 , Condutos Olfatórios/fisiologia , Semaforina-3A , Medula Espinal/fisiologia
10.
Acta Neurol Scand ; 118(1): 54-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18261166

RESUMO

BACKGROUND: Cerebral vasospasm following subarachnoid hemorrhage (SAH) is a significant cause of morbidity and mortality and recent studies indicate that Rho-kinase plays an important role in the occurrence of such cerebral vasospasm. Eicosapentaenoic acid (EPA), an n-3 polyunsaturated fatty acid, inhibits sphingosylphosphorylcholine (SPC)-induced Rho-kinase activation in vitro, so this study examined whether EPA prevented cerebral vasospasm occurrence after SAH in patients. METHODS: The trial population was 101 patients with SAH subjected to craniotomy and clip application. EPA was orally administered at a daily dose of 1800 mg EPA from day 4 to day 14 to 73 patients; the other 28 constituted the control group, receiving no EPA. RESULTS: EPA significantly curtailed both the occurrence of symptomatic vasospasm (14% EPA group, 36% control, P = 0.019) and of cerebral infarction because of cerebral vasospasm (4% EPA group, 29% control, P = 0.001). Moreover, the percentage of patients with a clinically good outcome was significantly higher in the EPA group (85%, P = 0.022) than in control (64%); there were no deaths in the EPA group but three (11%) in control (P = 0.020). CONCLUSION: These findings suggest EPA inhibits symptomatic cerebral vasospasm and cerebral infarction after SAH and also improves clinical prognosis.


Assuntos
Aneurisma Roto/terapia , Ácido Eicosapentaenoico/análogos & derivados , Aneurisma Intracraniano/terapia , Inibidores da Agregação Plaquetária/uso terapêutico , Hemorragia Subaracnóidea/terapia , Vasoespasmo Intracraniano/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Aneurisma Roto/complicações , Aneurisma Roto/diagnóstico , Ácido Eicosapentaenoico/uso terapêutico , Feminino , Seguimentos , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/diagnóstico , Resultado do Tratamento , Vasoespasmo Intracraniano/diagnóstico , Vasoespasmo Intracraniano/etiologia
11.
Acta Neurochir (Wien) ; 150(1): 31-9; discussion 39, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18058058

RESUMO

BACKGROUND: To evaluate our decision policy based on vertical aneurysm projection for selecting the side of the pterional approach for the surgical treatment of anterior communicating artery aneurysms. METHODS: Inferiorly projecting aneurysms were treated through the dominant A1 side, and superiorly projecting aneurysms were treated through the side of aneurysm fundus projection. We analysed postoperative outcome and surgical complications, and the correlations between the anatomical factors such as position (high or low), projection (dorsal or anterior), and the plane containing both A2 vessels (open A2 plane defined as the A2 of the approach side located more posteriorly than the contralateral A2; closed A2 plane as the ipsilateral A2 located more anteriorly than the contralateral A2), to assess the surgical requirements of approaches in patients with superiorly projecting aneurysms. FINDINGS: A favorable outcome was achieved in 95.1% of patients with inferior type aneurysms and 85.2% of patients with superior type aneurysms (P = 0.088). Surgical complications occurred in 8.9% of patients with inferior type aneurysms and 17.9% with superior type aneurysms. However, there was a distinct group of patients with superior type aneurysms characterised by a closed A2 plane, in which the ipsilateral A2 was located anterior to the contralateral A2, in whom the approach toward the neck was significantly more difficult, requiring A2 displacement or gyrus aspiration, and resulting in a neck remnant and more surgical complications such as vascular injury or cerebral contusion. This group also had a significantly high correlation with high position and dorsal projection of aneurysms causing more difficult dissection. CONCLUSIONS: This policy provided good postoperative outcomes. However, use of skull base techniques or the interhemispheric approach, instead of the normal pterional approach, may further improve the postoperative outcome for closed A2 plane aneurysms.


Assuntos
Aneurisma Roto/cirurgia , Aneurisma Intracraniano/cirurgia , Procedimentos Neurocirúrgicos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Feminino , Escala de Resultado de Glasgow , Humanos , Aneurisma Intracraniano/classificação , Aneurisma Intracraniano/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Resultado do Tratamento
12.
J Cardiovasc Surg (Torino) ; 48(3): 389-92, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17505446

RESUMO

Pulmonary adenocarcinoma complicated with a pulmonary infarction presenting as an intrapulmonary metastasis is relatively rare. We present a case of pulmonary infarction manifesting as intrapulmonary metastases of lung cancer. A previously healthy 59-year-old woman was admitted to our hospital on May 16, 2002 for evaluation of multiple abnormal radiographic shadows in the right lower lung field. Laboratory tests showed no abnormalities except for a slight elevation of carcinoembryonic antigens. Computed tomography of the chest revealed a hilar mass lesion with parenchymal lesions in the periphery of the right lower lobe, highly suspected to be a pulmonary adenocarcinoma with intrapulmonary metastases. A diagnosis of pulmonary adenocarcinoma was confirmed by a transbronchial brushing examination. A right middle and lower bilobectomy with mediastinal lymph node dissection was needed by hilum lymphadenopathy and a lower lobe invasion of the main tumor. Histopathological findings of the resected specimens revealed poorly differentiated adenocarcinoma of the lung with N1 (#11i) disease and multiple pulmonary infarctions with coagulation necrosis and recanalization. Pulmonary infarctions are demonstrated on chest x-rays as round or polygonal in shape, and located at the periphery of the same lobe as the primary tumor. Computed tomography is more sensitive than conventional radiography in the detection of pulmonary infarction. Our case suggests that pulmonary infarction associated with lung cancer should be considered as one important cause of peripheral pulmonary nodules.


Assuntos
Adenocarcinoma/complicações , Neoplasias Pulmonares/complicações , Embolia Pulmonar/complicações , Nódulo Pulmonar Solitário/etiologia , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/secundário , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Pessoa de Meia-Idade , Invasividade Neoplásica , Embolia Pulmonar/diagnóstico por imagem , Embolia Pulmonar/etiologia , Embolia Pulmonar/patologia , Nódulo Pulmonar Solitário/diagnóstico por imagem , Nódulo Pulmonar Solitário/patologia , Tomografia Computadorizada por Raios X
13.
Curr Opin Neurobiol ; 8(5): 587-92, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9811625

RESUMO

Chemorepulsive signals that repel or paralyze neuronal growth cones have been found to play important roles in axon guidance in a stereotyped manner. Recent progress in the identification of neuropilins as the receptors for class III secreted collapsin/semaphorin subfamily members, which are neuronal repellents, and in the analysis of mutant mice lacking neuropilin function has confirmed the importance of these chemorepellents in axon guidance. In addition, characterization of the neuropilin protein has yielded new insights into the functions of this molecule in vascular formation and in axon guidance.


Assuntos
Química Encefálica/fisiologia , Glicoproteínas/análise , Proteínas do Tecido Nervoso/análise , Animais , Glicoproteínas/metabolismo , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Neuropilina-1 , Receptores de Superfície Celular/análise , Receptores de Superfície Celular/metabolismo , Semaforina-3A , Transdução de Sinais/fisiologia
14.
J Neurosci ; 21(7): 2373-9, 2001 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11264311

RESUMO

During development, mitral cells, the major output neurons of the olfactory bulb, project their axons caudolaterally into the telencephalon and form the lateral olfactory tract (LOT). Two types of guidance cues have been suggested for this projection. First, a long-range factor Slit, which is secreted from the septum, repels mitral cell axons into a caudolateral direction. Second, the pathway of mitral cell axons contains a subset of neurons designated as lot cells, which guide the axons through short-range interactions. It is not clear how these two guidance cues relate to each other and how they share the physiological roles. Here we examined the behavior of mitral cell axons in organotypic culture on ectopic application of Slit and inhibition of endogenous Slit signaling. The results suggested that the short-range guidance cue in the LOT pathway functions independently from Slit. Furthermore, our results showed that removal of the septum and inhibition of Slit signaling did not affect the projection of mitral cell axons. Although the septum and exogenous Slit can repel olfactory bulb axons, our results cast doubts on the physiological relevance of the septum and endogenous Slit in guiding the projection of mitral cell axons.


Assuntos
Axônios/fisiologia , Bulbo Olfatório/fisiologia , Fatores de Transcrição/fisiologia , Animais , Efrina-A2 , Camundongos , Técnicas de Cultura de Órgãos , Telencéfalo/fisiologia
15.
Biochim Biophys Acta ; 886(1): 57-63, 1986 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-3006790

RESUMO

Calmodulin-dependent protein kinase II was purified from rabbit brain and its properties were compared with those of calmodulin-dependent protein kinase II from rat brain and calmodulin-dependent glycogen synthase kinase from rabbit skeletal muscle. Rabbit brain calmodulin-dependent protein kinase II was clearly distinguished from rabbit skeletal muscle glycogen synthase kinase with respect to size, behavior on autophosphorylation, immunological cross-reactivity and peptide mapping, but was indistinguishable from rat brain calmodulin-dependent protein kinase II in all respects examined. Thus, differences between calmodulin-dependent protein kinase II and glycogen synthase kinase appear not to reflect a species difference but to reflect a tissue difference.


Assuntos
Encéfalo/enzimologia , Músculos/enzimologia , Proteínas Quinases/metabolismo , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Calmodulina/farmacologia , Ativação Enzimática , Quinases da Glicogênio Sintase , Soros Imunes , Cinética , Peso Molecular , Fosforilação , Proteínas Quinases/isolamento & purificação , Coelhos , Ratos , Especificidade da Espécie , Especificidade por Substrato , Triptofano Hidroxilase/metabolismo
16.
Biochim Biophys Acta ; 968(1): 77-85, 1988 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-2827788

RESUMO

Phosphorylation of microtubule-associated protein 2 (MAP 2) by Ca2+-, calmodulin-dependent protein kinase II (protein kinase II) inhibited the actin filament cross-linking activity of MAP 2. This inhibition required the presence of ATP, Mg2+, Ca2+ and calmodulin. The minimal concentration of MAP 2 required for gel formation of actin filaments was increased with increasing amounts of phosphate incorporated into MAP 2, and the phosphorylated MAP 2, into which 10.3 mol of phosphate/mol of protein had been incorporated, did not cause actin filaments to gel under the experimental conditions used. The phosphorylation of MAP 2 by Ca2+-, phospholipid-dependent protein kinase (protein kinase C) and cAMP-dependent protein kinase also inhibited the actin filament cross-linking activity of MAP 2. The extent and rate of phosphorylation of MAP 2 by protein kinase II were higher than those of the phosphorylation by protein kinase C and cAMP-dependent protein kinase. The interaction of actin filaments with MAP 2 was inhibited more by the actions of protein kinase II and protein kinase C than by cAMP-dependent protein kinase. The actin filament cross-linking activity of MAP 2 phosphorylated either by protein kinase II, cAMP-dependent protein kinase or protein kinase C was retrieved when phosphorylated MAP 2 was treated by protein phosphatase. These results indicate that the interaction of actin filaments with MAP 2 is regulated by the phosphorylation-dephosphorylation of MAP 2.


Assuntos
Actinas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Quinases/metabolismo , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Córtex Cerebral/enzimologia , Concentração de Íons de Hidrogênio , Cinética , Músculos/metabolismo , Fosforilação , Proteína Quinase C/metabolismo , Coelhos , Ratos
17.
Biochim Biophys Acta ; 991(1): 44-9, 1989 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-2713421

RESUMO

A protein inhibiting a protein inhibitor (antizyme) to ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) (ODC), antizyme inhibitor, was purified from the liver cytosol of thioacetamide-treated rats by procedures including antizyme affinity chromatography. Overall purification was roughly estimated to be about 17,000,000-fold and recovery was about 2.4%. The purified preparation showed one major protein band and a faint band corresponding in mobility to molecular weights of 51,000 and 53,500, respectively, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Judging from the ornithine decarboxylase activity of the final preparation, the faint band may be ornithine decarboxylase. The apparent molecular weight of antizyme inhibitor estimated by gel filtration on Sephacryl S-200 was approx. 62,000, indicating that antizyme inhibitor may be composed of a single polypeptide chain. In order to examine the question of whether antizyme inhibitor is a protein derived from ornithine decarboxylase, an inactive ornithine decarboxylase, in an immunotitration study and analysis of the binding to antizyme were investigated. The results indicate that antizyme inhibitor may be a protein distinct from ornithine decarboxylase.


Assuntos
Proteínas de Transporte , Fígado/enzimologia , Inibidores da Ornitina Descarboxilase , Proteínas/isolamento & purificação , Animais , Anticorpos/análise , Sítios de Ligação , Cromatografia de Afinidade , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Feminino , Peso Molecular , Proteínas/imunologia , Piridoxamina , Ratos , Ratos Endogâmicos
18.
Biochim Biophys Acta ; 614(2): 313-27, 1980 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-7407194

RESUMO

Phenylalanine 4-monooxygenase (L-phenylalanine, tetrahydropteridine:oxygen oxidoreductase (4-hydroxylating), EC 1.14.16.1) was purified approx. 600-fold to apparent homogeneity with a 48% yield from rat liver. Two distinct active forms were separable by calcium phosphate gel chromatography and numbered based on their order of elution from the gel column. The predominant form, Form I, had an estimated molecular weight of about 240 000. The enzyme gave a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis, the molecular weight of which was estimated to be approx. 51 000, indicating that the enzyme might be composed of four identical subunits. The molecular properties of Form I were: sedimentation coefficient, 10.1 S; Stokes radius, 55 A degrees; diffusion coefficient, 3.90 x 10(-7) cm2/s; frictional ratio, 1.33 and isoelectric point, pH 5.6. The enzyme contained approx. 0.6 mol of iron and 0.3 mol of phosphate/mol of subunit of the enzyme. No significant differences in kinetic properties of the two forms, Form I and Form II, were observed. Amino acid analysis studies revealed that the amino acid composition of Form I was essentially identical with that of Form II, indicating that both forms might be the products of the same gene. There were, however, minor differences in the phosphate content and the isoelectric point between the two forms.


Assuntos
Fígado/enzimologia , Fenilalanina Hidroxilase/análise , Aminoácidos/análise , Animais , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Cinética , Masculino , Peso Molecular , Fenilalanina Hidroxilase/metabolismo , Ratos
19.
Biochim Biophys Acta ; 658(2): 327-33, 1981 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-6113846

RESUMO

The acetone precipitation of a partially purified tyrosine 3-monooxygenase (L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2) resulted in the complete loss of enzymatic activity. The enzymatic activity was restored by incubation with iron and dithiothreitol. The restoration of the activity was a pH-, temperature- and time-dependent reaction. Since cobalt, nickel, copper, zinc, manganese, cadmium, magnesium calcium and barium ions were all ineffective in restoring activity, iron ion appeared to be specifically required in the restoration of the enzyme activity. Dithiothreitol could be partially replaced in the restoration step by glutathione, 2-mercaptoethanol or cysteine.


Assuntos
Acetona/farmacologia , Ferro/farmacologia , Reagentes de Sulfidrila/farmacologia , Tirosina 3-Mono-Oxigenase/antagonistas & inibidores , Medula Suprarrenal/enzimologia , Animais , Precipitação Química , Ditiotreitol/farmacologia , Reativadores Enzimáticos , Técnicas In Vitro , Ratos , Tirosina 3-Mono-Oxigenase/metabolismo
20.
Biochim Biophys Acta ; 799(3): 260-9, 1984 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-6733150

RESUMO

Dopamine beta-monooxygenase was extensively purified from rat adrenal. The specific activity of the final preparation was approx. 1500 nmol/min per mg protein, which was much higher than the highest yet reported. As judged by gel filtration on Ultrogel AcA22, SDS-polyacrylamide gel electrophoresis, and cross-linking studies, the enzyme appeared to be composed of four identical subunits, each possessing a molecular weight of 88 000. The isoelectric point of the enzyme was estimated to be pH 6.6 in the presence of 8 M urea. Spleen cells from BALB/c mice immunized with rat dopamine beta-monooxygenase were fused to P3-X63-Ag8-653 mouse myeloma cells. From 55 hybrid cells, 10 stable clones secreting anti-dopamine beta-monooxygenase antibody were obtained. Antibody from one clone was coupled to CNBr-activated Sepharose 4B and the monoclonal antibody-Sepharose was shown to be very useful to isolate rat dopamine beta-monooxygenase from crude preparations.


Assuntos
Medula Suprarrenal/enzimologia , Anticorpos Monoclonais/isolamento & purificação , Dopamina beta-Hidroxilase/isolamento & purificação , Aminoácidos/análise , Animais , Cromatografia de Afinidade , Cromatografia em Gel , Dopamina beta-Hidroxilase/imunologia , Focalização Isoelétrica , Camundongos , Camundongos Endogâmicos BALB C , Peso Molecular , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA