Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Mol Phylogenet Evol ; 67(1): 140-55, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23306305

RESUMO

We explore the relationships within Serraniformes (Li et al., 2009) using a dense taxon sampling and seven nuclear markers. Six had already used been for teleost phylogeny (IRBP, MC1R, MLL4, Pkd1, Rhodopsin, and RNF213) at other scales, and one (MLL2) is new. The results corroborate the composition of Serraniformes described in previous publications (some Gasterosteiformes, Perciformes and Scorpaeniformes). Within the clade, Notothenioidei and Zoarcoidei are each monophyletic. Cottoidei was not monophyletic due to placement of the genus Ebinania (Psychrolutidae). Our independent data confirm the sister-group relationship of Percophidae and Notothenioidei as well as the division of Platycephaloidei in four different groups (Bembridae, Platycephalidae, Hoplichthyidae and Peristediidae with Triglidae). Within Cottoidei, Liparidae and Cyclopteridae formed a clade associated with Cottidae, the genus Cottunculus (Psychrolutidae), and Agonidae. Serranidae and Scorpaenidae are not monophyletic, with the Serranidae divided in two clades (Serraninae and Epinephelinae/Anthiinae) and Scorpaenidae including Caracanthidae and the genus Ebinania (Psychrolutidae). We discuss some morphological characters supporting clades within the Scorpaenidae.


Assuntos
Evolução Biológica , Peixes/classificação , Filogenia , Animais , Teorema de Bayes , Núcleo Celular/genética , Peixes/genética , Marcadores Genéticos , Funções Verossimilhança , Modelos Genéticos , Análise de Sequência de DNA
3.
J Plant Res ; 121(2): 163-77, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18246297

RESUMO

Crassulacean acid metabolism (CAM) is one of the photosynthetic pathways regarded as adaptations to water stress in land plants. Little is known about correlations among the level of CAM activity, environment of habitat, life form, and phylogenetic relationship of a plant group from an evolutionary perspective. We examined these relationships in 18 species of Cymbidium (Orchidaceae) because the genus shows distinctive diversification of habitats and life forms. The photosynthetic type was classed into three categories, strong CAM, weak CAM, and C(3) on the basis of CAM activity. CAM expression in Cymbidium was confined to the epiphytic and lithophytic species. Especially, all of these species from tropical to subtropical rainforest exhibited CAM activity. On the other hand, the terrestrial species always exhibited C(3) metabolism irrespective of their varied habitats. Regarding the evolution of photosynthetic characters, weak CAM was the ancestral state in Cymbidium and strong CAM and C(3) metabolism occurred subsequently. The evolution of strong CAM likely enabled Cymbidium to extend to exposed sites in tropical lowland where marked water stress exists. Further, different levels of CAM activity characterized each species and such potential plasticity of CAM may realize the radiation of Cymbidium into sites with different environmental conditions.


Assuntos
Malato Desidrogenase/metabolismo , Orchidaceae/enzimologia , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Fotossíntese , Evolução Biológica , Isótopos de Carbono/metabolismo , Ritmo Circadiano , Ecossistema , Malatos/metabolismo , Orchidaceae/anatomia & histologia , Orchidaceae/classificação , Folhas de Planta/anatomia & histologia
5.
Ann Bot ; 97(4): 513-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16464877

RESUMO

UNLABELLED: BACKGROUND AND AIMS Silica deposition is one of the important characteristics of the family Poaceae. The distribution, deposition process and physiology of silica in this family have been extensively investigated. Bamboos among members of Poaceae have leaves with a fairly long life span, and the leaves continuously accumulate silica in their tissues throughout their life, not only during the course of leaf opening, but also after opening. It has been revealed that the silica deposition process in relation to ageing of the bamboo leaf after opening differed depending on the cell types comprising the tissues. However, silica deposition has never been examined during the development and maturation periods of bamboo leaves. Hence, to clarify the silica deposition process in a developmental stage of the bamboo leaf, distribution of silica was observed in the abaxial epidermis before the opening of the leaf blades of Pleioblastus chino. METHODS: Abaxial epidermal tissues of leaves were examined using a scanning electron microscope equipped with an energy dispersive X-ray microanalyser. KEY RESULTS: Among seven cell types comprising the abaxial epidermis, three types of cells, guard cells, prickle hairs and silica cells, deposited silica conspicuously, and another four types, cork cells, long cells, micro hairs and subsidiary cells, deposited only a little silica. Among the former group of cell types, silica cells and guard cells deposited silica over their entire surfaces, while prickle hairs deposited silica only in the point-tips. Silica deposition was detected firstly in prickle hairs, and then in silica cells and guard cells. Only silica cells were assumed to deposit silica conspicuously before leaf opening but not conspicuously after opening. CONCLUSIONS: Cell types in leaf epidermis of bamboo are classified into three groups according to the silica deposition pattern. Silica deposition in silica cells may be positive as a part of the physiological activities of leaves.


Assuntos
Epiderme Vegetal/metabolismo , Folhas de Planta/metabolismo , Poaceae/metabolismo , Dióxido de Silício/metabolismo , Diferenciação Celular , Epiderme Vegetal/citologia , Epiderme Vegetal/ultraestrutura , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/ultraestrutura , Poaceae/citologia , Poaceae/crescimento & desenvolvimento , Poaceae/ultraestrutura
6.
Kyobu Geka ; 57(3): 215-8, 2004 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-15035077

RESUMO

Cardiac myxoma of right ventricle is rare. We report a 16-year-old girl who underwent an emergent surgical resection of right ventricular myxoma. She had syncopal attach in going to school and was referred to our hospital in emergency. There were no abnormal findings in brain computed tomography (CT) and electroencephalogram, but Levine IV/VI systolic ejection murmur was heard. Echocardiography and magnetic resonance imaging (MRI) revealed the presence of large mass in the right ventricle which was floating into the pulmonary artery. The tumor was removed completely through the both of main pulmonary artery and right atrium using cardiopulmonary bypass. The tumor was attached to the right ventricle free wall by a pedicle, which was 5 x 3 cm in size and was diagnosed as myxoma by histopathological examination.


Assuntos
Neoplasias Cardíacas/complicações , Mixoma/complicações , Síncope/etiologia , Adolescente , Procedimentos Cirúrgicos Cardiovasculares , Diagnóstico por Imagem , Feminino , Neoplasias Cardíacas/diagnóstico , Neoplasias Cardíacas/cirurgia , Ventrículos do Coração , Humanos , Mixoma/diagnóstico , Mixoma/cirurgia , Resultado do Tratamento
7.
Ann Bot ; 93(3): 235-48, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14744706

RESUMO

BACKGROUND AND AIMS: Silica deposition is one of the important characteristics of plants in the family Poaceae. There have been many investigations into the distribution, deposition and physiological functions of silica in this family. Two hypotheses on silica deposition have been proposed based on these studies. First, that silica deposition occurs passively as a result of water uptake by plants, and second, that silica deposition is controlled positively by plants. To test these two apparently contradictory hypotheses, silica deposition in relation to the ageing of leaf tissues in Sasa veitchii was investigated. METHODS: Tissues were examined using a light microscope and a scanning electron microscope equipped with an energy dispersive X-ray microanalyser. KEY RESULTS: The deposition process differed depending on cell type. In mesophyll tissue, fusoid cells deposited large amounts of silica depending on leaf age after maturation, while chlorenchyma cells deposited little. In epidermal tissue, comprised of eight cell types, only silica cells deposited large amounts of silica during the leaf's developmental process and none after maturation. Bulliform cells, micro-hairs and prickle hairs deposited silica densely and continuously after leaf maturation. Cork cells, guard cells, long cells and subsidiary cells deposited silica at low levels. CONCLUSIONS: The significance of these observations is discussed in relation to the two hypotheses proposed for silica deposition in Poaceae. The results of the present study clearly indicate that both hypotheses are compatible with each other dependent on cell types.


Assuntos
Folhas de Planta/metabolismo , Sasa/metabolismo , Dióxido de Silício/metabolismo , Microscopia Eletrônica de Varredura , Epiderme Vegetal/crescimento & desenvolvimento , Epiderme Vegetal/metabolismo , Epiderme Vegetal/ultraestrutura , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/ultraestrutura , Sasa/crescimento & desenvolvimento , Sasa/ultraestrutura
8.
Ann Bot ; 90(1): 149-52, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12125768

RESUMO

Silica accumulation in long-lived leaves of Sasa veitchii was investigated using the molybdenum blue method. In general, silica accumulation was rapid during spring and summer, and slow during winter. The leaves continuously accumulate silica throughout their life. The significance of these observations is discussed in relation to two hypotheses for silica accumulation in plants: (1) that silica accumulation is a result of water consumption by the plant: and (2) that silica is actively accumulated to protect the plant. The results of the present study support the former hypothesis.


Assuntos
Poaceae/metabolismo , Dióxido de Silício/metabolismo , Folhas de Planta/metabolismo
9.
J Hand Surg Am ; 26(6): 1120-4, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11721262

RESUMO

Four cases of fingertip replantation using a single volar arteriovenous anastomosis and drainage with a transverse tip incision are reported. Because of lack of suitable arteries for anastomosis in the amputated finger, in each case a volar radial vein was anastomosed to the proximal digital artery and external drainage was performed through a transverse tip incision. In 3 cases the replanted fingertip survived completely; partial necrosis occurred in 1 case. Because veins are more superficial and larger than arteries, they are more available for anastomosis. The results indicate that this method is a useful alternative in fingertip replantation.


Assuntos
Amputação Traumática/cirurgia , Traumatismos dos Dedos/cirurgia , Dedos/cirurgia , Reimplante/métodos , Adulto , Anastomose Cirúrgica/métodos , Artérias/cirurgia , Drenagem/métodos , Dedos/irrigação sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Veias/cirurgia
10.
Neurotoxicology ; 22(3): 329-39, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11456334

RESUMO

Type I and type II pyrethroids are known to modulate the sodium channel to cause persistent openings during depolarization and upon repolarization. Although there are some similarities between the two types of pyrethroids in their actions on sodium channels, the pattern of modification of sodium currents is different between the two types of pyrethroids. In the present study, interactions of the type I pyrethroid tetramethrin and the type II pyrethroid deltamethrin at rat hippocampal neuron sodium channels were investigated using the inside-out single-channel patch clamp technique. Deltamethrin-modified sodium channels opened much longer than tetramethrin-modified sodium channels. When 10 microM tetramethrin was applied to membrane patches that had been exposed to 10 microM deltamethrin, deltamethrin-modified prolonged single sodium currents disappeared and were replaced by shorter openings which were characteristic of tetramethrin-modified channel openings. These single-channel data are compatible with previous whole-cell competition study between type I and type II pyrethroids. These results are interpreted as being due to the displacement of the type II pyrethroid molecule by the type I pyrethroid molecule from the same binding site or to the allosteric interaction of the two pyrethroid molecules at separate sodium channel sites.


Assuntos
Hipocampo/efeitos dos fármacos , Inseticidas/farmacologia , Neurônios/efeitos dos fármacos , Piretrinas/farmacologia , Canais de Sódio/metabolismo , Animais , Células Cultivadas , Interações Medicamentosas , Embrião de Mamíferos , Feminino , Hipocampo/fisiologia , Neurônios/fisiologia , Nitrilas , Gravidez , Ratos , Ratos Sprague-Dawley
11.
Ann Plast Surg ; 47(6): 620-4, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11756831

RESUMO

Twenty cases of fresh nasal bone fractures were examined for which computed tomographic (CT) scans were obtained at the time of initial consultation, immediately after surgery, and 1 month after surgery. CT scans were obtained in the axial position from the nasal bone to the nasal apex, with slice intervals and slice thicknesses of 2 mm. For evaluation after reduction, classification of fracture and measurement of angle (0) of the fractured portion were performed by CT examination. The authors considered angles close to 0 deg to indicate good reduction. In addition, they performed overall evaluation based on the shape of the arch formed by the nasal bone and maxilla. Based on this, they compared the result of evaluation immediately after surgery with that found 1 month after surgery. Evaluation of reduction by CT examination performed immediately after surgery revealed excellent results in 2 patients, good results in 10 patients, and fair results in 8 patients. Reevaluation of reduction by CT 1 month after surgery revealed excellent results in 10 patients, good results in 9 patients, and fair results in 1 patient. The shape of the nasal bone tended to improve with time.


Assuntos
Osso Nasal/lesões , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osso Nasal/diagnóstico por imagem , Osso Nasal/cirurgia , Cuidados Pós-Operatórios , Fraturas Cranianas/diagnóstico por imagem , Fraturas Cranianas/cirurgia , Tomografia Computadorizada por Raios X
12.
J Membr Biol ; 177(1): 23-39, 2000 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10960151

RESUMO

Pyrethroid modulation of sodium channels is unique in the sense that it is highly dependent on temperature, the potency being augmented by lowering the temperature. To elucidate the mechanisms underlying the negative temperature dependence of pyrethroid action, single sodium channel currents were recorded from cultured rat hippocampal neurons using the inside-out configuration of patch-clamp technique, and the effects of the pyrethroid tetramethrin were compared at 22 and 12 degrees C. Tetramethrin-modified sodium channels opened with short closures and/or transitions to subconductance levels at 22 and 12 degrees C. The time constants of the burst length histograms for tetramethrin-modified channels upon depolarization to -60 mV were 7. 69 and 14.46 msec at 22 and 12 degrees C, respectively (Q(10) = 0. 53). Tetramethrin at 10 microm modified 17 and 23% of channels at 22 and 12 degrees C, respectively, indicating that the sensitivity of the sodium channel of rat hippocampal neurons to tetramethrin was almost the same as that of tetrodotoxin-sensitive sodium channels of rat dorsal root ganglion neurons and rat cerebellar Purkinje neurons. The time constants for burst length in tetramethrin-modified sodium channels upon repolarization to -100 mV from -30 mV were 8.26 and 68. 80 msec at 22 and 12 degrees C (Q(10) = 0.12), respectively. The prolongation of tetramethrin-modified whole-cell sodium tail currents upon repolarization at lower temperature was ascribed to a prolongation of opening of each channel. Simple state models were introduced to interpret behaviors of tetramethrin-modified sodium channels. The Q(10) values for transition rate constants upon repolarization were extremely large, indicating that temperature had a profound effect on tetramethrin-modified sodium channels.


Assuntos
Hipocampo/efeitos dos fármacos , Inseticidas/farmacologia , Piretrinas/farmacologia , Canais de Sódio/efeitos dos fármacos , Animais , Feminino , Hipocampo/citologia , Hipocampo/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Canais de Sódio/fisiologia , Temperatura
13.
Ann Plast Surg ; 45(1): 61-3, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10917100

RESUMO

The authors encountered a case of elongated uvula with a pleomorphic adenoma originating from the minor salivary gland, causing frequent upper airway obstruction. A 75-year-old woman had obstructive sleep apnea syndrome brought about by the swallowing impact of the pendulous tumor into the hypopharyngeal and supralaryngeal spaces. Although there are some case reports about tumors originating from the uvula, this is the first reported to cause obstructive sleep apnea syndrome.


Assuntos
Adenoma Pleomorfo/complicações , Neoplasias das Glândulas Salivares/complicações , Apneia Obstrutiva do Sono/etiologia , Úvula/anormalidades , Idoso , Feminino , Humanos
14.
Kyobu Geka ; 53(3): 246-50, 2000 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-10714118

RESUMO

We have recently experienced two cases of traumatic diaphragmatic hernia which has been repaired by surgery. The first case was a 58-year-old man who had suffered left upper abdominal injury with a branch in his childhood. Although he had never symptoms, chest X-ray showed abnormal shadow in the left lower lung field. Radiologic studies indicated that the great omentum was escaped into the thoracic cavity. On patient request, we performed primary repair of the diaphragmatic hernia on thoracotomy. The second case was a 56-year-old woman who had undergone a left nephrectomy for the left renal abscess. Seven months after the operation, she began to feel nausea and vomiting, and the symptom aggravated with time. Chest X-ray showed air bubbles in the left lower lung field. It proved to be a projection of the stomach into the thoracic cavity through the iatrogenic diaphragmatic injury. We successfully performed a repairment of the diaphragm with a mesh.


Assuntos
Hérnia Diafragmática Traumática/cirurgia , Doença Iatrogênica , Feminino , Hérnia Diafragmática Traumática/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Torácicos , Resultado do Tratamento
15.
Ann Plast Surg ; 42(1): 87-91, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9972724

RESUMO

The authors present 2 patients with greater sphenoid wing fractures that were treated surgically. This type of fracture is classified as a blow-in fracture of the lateral orbital wall. The first patient was a 16-year-old boy who was involved in a motor vehicle accident. Computed tomography (CT) disclosed a medial displacement of the inner wall of the greater sphenoid wing of the left orbit. He was unconscious for 3 days. After he recovered consciousness, he presented limited abduction of the left eye with diplopia in all gaze directions and mild left proptosis. Although these symptoms did not improve for 1 week, displaced bone fragments of the greater sphenoid wing were removed via the lateral orbital approach. The patient had a good postoperative course with progressive improvement in eye movement over the next several weeks. The second patient was a 22-year-old man whose face was hit in a fight. CT disclosed medial displacement of the inner wall of the greater sphenoid wing of the left orbit. Although the patient also presented limited abduction of the left eye on admission, this symptom improved gradually. However, diplopia in all gaze directions and mild left proptosis did not improve. Therefore, the displaced inner wall of the greater sphenoid wing was reduced via the lateral orbital approach. The patient showed a good postoperative course with progressive improvement over the next several weeks. This type of orbital fracture, which is classified as an orbital blow-in fracture, is relatively rare. This type of greater sphenoid wing fracture is caused by buckling of the orbital wall secondary to severe compression of the orbital rim. Surgical treatment using the lateral orbital approach through a hemicoronal skin incision afforded a wider operative field and better cosmetic result.


Assuntos
Fraturas Orbitárias/cirurgia , Adolescente , Adulto , Humanos , Masculino , Fraturas Orbitárias/diagnóstico por imagem , Tomografia Computadorizada por Raios X
16.
Neuroreport ; 9(8): 1769-75, 1998 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9665598

RESUMO

Alcohol modulation of single-channel kinetics of GABA(A) receptor currents was studied with rat dorsal root ganglion neurons using the excised outside-out patch clamp technique. GABA (1 microM) alone or GABA (1 microM) plus ethanol (30-300 mM) or n-Octanol (30-300 microM) were applied by pressure ejection to evoke single-channel currents. The main single-channel conductance was not changed by either ethanol or n-Octanol at 25 pS. Both alcohols exerted the same effects on the single-channel kinetics, although n-Octanol was more potent than ethanol. The frequency of openings, the mean open time, the percentage of open time, the frequency of bursts, and the mean burst duration were all increased, but the mean closed time was decreased. These changes in channel kinetics account for the increase in whole-cell current amplitude caused by ethanol and n-Octanol.


Assuntos
1-Octanol/farmacologia , Etanol/farmacologia , Moduladores GABAérgicos/farmacologia , Gânglios Espinais/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Receptores de GABA-A/efeitos dos fármacos , Animais , Gânglios Espinais/citologia , Cinética , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos
17.
Pflugers Arch ; 434(1): 84-90, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9094259

RESUMO

The mechanism underlying the enhancement of the high-voltage-activated (HVA) Ca2+ current (ICa) after application of baclofen, a GABAB agonist, in neurones of the rat dorsal root ganglia was studied by a combined use of the nystatin perforated patch clamp recording and our rapid superfusion system. Baclofen (50 microM) decreased the peak amplitude of HVA ICa and slowed the onset of the current, i.e. produced a typical G-protein-mediated inhibition of ICa. However, when baclofen was rapidly removed from the medium, the amplitude of the current was rather augmented, exceeding the control value obtained before application of the drug. This enhancement was not due to a shift of the voltage dependence of Ca2+ channel activation or a change in ionic permeability to other ions. The enhancement of HVA ICa by baclofen was sensitive to pertussis toxin treatment. The enhancement was evident during superfusion of baclofen. Since the inhibitory effect of baclofen on HVA ICa was not attenuated, even after a continuous application of baclofen for 10 min, the enhancement was not due to relief from tonic G-protein-mediated inhibition of the current or a desensitization of the GABAB receptor-effector system. An extremely prolonged time course of the enhancement of HVA ICa by baclofen strongly suggests an involvement of some intracellular signal transduction system.


Assuntos
Baclofeno/farmacologia , Canais de Cálcio/efeitos dos fármacos , Gânglios Espinais/efeitos dos fármacos , Receptores de GABA-A/fisiologia , Regulação para Cima/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Ratos , Receptores de GABA-A/efeitos dos fármacos
18.
Plast Reconstr Surg ; 99(2): 543-6, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9030165

RESUMO

We treated a case of postoperative osteomyelitis and epidural abscess in the left temporal and parietal region. The scalp and skull defect following debridement was reconstructed immediately with an arterialized occipitoparietal osteocutaneous flap that was supplied proximally by the occipital artery and distally by the superficial temporal artery. This method is one of the alternative methods for small to moderately sized skull and scalp defects in the temporal, parietal, and occipital areas without available superficial temporal artery.


Assuntos
Osteomielite/cirurgia , Crânio/cirurgia , Retalhos Cirúrgicos/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Osso Occipital , Osso Parietal , Retalhos Cirúrgicos/irrigação sanguínea
19.
Seishin Shinkeigaku Zasshi ; 98(8): 533-54, 1996.
Artigo em Japonês | MEDLINE | ID: mdl-8952368

RESUMO

In recent years, misidentification syndromes have attracted much attention, and various types of these syndromes have been recognized. However, misidentification syndromes tend to be discussed as case reports or as a whole, and yet there is no established classification. This is primarily due to a small number of cases encountered by each researcher. We propose a new classification of misidentification syndrome based on more than 70 patients with these syndromes, who have been treated at one psychiatric hospital during 20 years. First, delusional misidentification syndromes were classified into two types: misidentification of human relationships represented by descent delusion (relational misidentification), and misidentification of identity itself represented by Capgras symptom and Fregoli symptom (identical misidentification). Next, identical misidentification was subclassified into 3 types: division of identity (divided type), union of identity (unionized type), and transformation of identity (transformed type). Various misidentification syndromes and associated signs and symptoms were evaluated in detail from the aspect of descriptive psychiatry and were compared with our new classification. In addition, this typological study on misidentification was analyzed based on the regressive theory and Jacksonism, and we proposed a hypothesis that there is correspondence between misidentification syndromes and the development of person identification in infants.


Assuntos
Transtornos Psicóticos/classificação , Síndrome de Capgras/classificação , Síndrome de Capgras/psicologia , Delusões/classificação , Delusões/psicologia , Humanos , Transtornos Psicóticos/psicologia
20.
Pflugers Arch ; 431(2): 221-9, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9026782

RESUMO

The properties of voltage-gated Na+ channels were studied in neurones isolated from rat dorsal root ganglia using the outside-out configuration of the patch-clamp technique. Two types of single-channel currents were identified from the difference in unit amplitudes. Neither type was evoked in the medium in which extracellular Na+ ions were replaced by an equimolar amount of tetramethylammonium ions. The two types of single-channel currents differed in their sensitivity to tetrodotoxin (TTX). The smaller channel current was insensitive to 1 microM TTX (referred to as TTX-I), while the larger channel current was blocked by 1 nM TTX (TTX-S). The unit amplitudes measured during a step depolarization to -30 mV (1.4 mM internal and 250 mM external Na+ concentrations) were 1.16 pA for TTX-S and 0.57 pA for TTX-I, respectively. The slope conductance measured at -30 mV was 16.3 pS for TTX-S and 8.5 pS for TTX-I. TTX-S could be activated by step depolarizations positive to -60 mV, while TTX-I could be activated at potentials positive to -40 mV. When the test pulse was preceded by a depolarizing prepulse, the prepulse positive to -50 mV preferentially inactivated TTX-S with a minimal effect on TTX-I. Activation and inactivation time courses of the averaged ensemble currents computed from TTX-S showed remarkable resemblances to the time courses of the macroscopic TTX-sensitive Na+ current. Similarly, the ensemble currents of TTX-I mimicked the macroscopic TTX-insensitive Na+ current. It was concluded that the two types of Na+ channels in rat dorsal root ganglia differ not only in their sensitivity to TTX, but also in their single-channel conductances.


Assuntos
Gânglios Espinais/metabolismo , Canais de Sódio/metabolismo , Animais , Animais Recém-Nascidos , Gânglios Espinais/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Canais de Sódio/efeitos dos fármacos , Tetrodotoxina/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...