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1.
Nature ; 581(7806): 47-52, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32376964

RESUMO

The recently discovered flat electronic bands and strongly correlated and superconducting phases in magic-angle twisted bilayer graphene (MATBG)1,2 crucially depend on the interlayer twist angle, θ. Although control of the global θ with a precision of about 0.1 degrees has been demonstrated1-7, little information is available on the distribution of the local twist angles. Here we use a nanoscale on-tip scanning superconducting quantum interference device (SQUID-on-tip)8 to obtain tomographic images of the Landau levels in the quantum Hall state9 and to map the local θ variations in hexagonal boron nitride (hBN)-encapsulated MATBG devices with relative precision better than 0.002 degrees and a spatial resolution of a few moiré periods. We find a correlation between the degree of θ disorder and the quality of the MATBG transport characteristics and show that even state-of-the-art devices-which exhibit correlated states, Landau fans and superconductivity-display considerable local variation in θ of up to 0.1 degrees, exhibiting substantial gradients and networks of jumps, and may contain areas with no local MATBG behaviour. We observe that the correlated states in MATBG are particularly fragile with respect to the twist-angle disorder. We also show that the gradients of θ generate large gate-tunable in-plane electric fields, unscreened even in the metallic regions, which profoundly alter the quantum Hall state by forming edge channels in the bulk of the sample and may affect the phase diagram of the correlated and superconducting states. We thus establish the importance of θ disorder as an unconventional type of disorder enabling the use of twist-angle gradients for bandstructure engineering, for realization of correlated phenomena and for gate-tunable built-in planar electric fields for device applications.

2.
Acta Anaesthesiol Scand ; 56(7): 866-71, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22404219

RESUMO

BACKGROUND: We aimed to investigate the effects of active mild hyperthermia and the effects of active mild hyperthermia with propofol on mortality and inflammatory responses during endotoxin-induced shock in rats. METHODS: Intravenous Escherichia coli endotoxin (15 mg/kg over 2 min) was injected in 48 rats. The animals were randomly allocated to one of the following four groups (n = 12 per group): normothermia group (group N), rectal temperature maintained between 36 °C and 38 °C; hyperthermia group (group H), rectal temperature was moderate and maintained between 39 °C and 40 °C; propofol with normothermia group (group PN), propofol (10 mg/kg/h) was administered, and temperature was between 36 °C and 38 °C; Propofol with hyperthermia group (group PH), propofol (10 mg/kg/h) administrated, and temperatures were maintained between 39 °C and 40 °C. The primary outcome was mortality 8 h after endotoxin injection. Secondary outcomes included changes in haemodynamics, arterial blood gases and plasma cytokine concentrations for the 8-h observation period. RESULTS: Mortality rates 8 h after endotoxin injection were 92%, 100%, 68% and 50% for N, H, PN and PH groups, respectively. There was no difference in hypotension, acidosis, and increase in plasma cytokine concentrations between N and H groups, but these parameters were attenuated in group PH. CONCLUSION: The mortality rates in the present study were extremely high; further hypotension and elevations in plasma pro-inflammatory and anti-inflammatory cytokine concentrations after endotoxin injection were not attenuated by mild hyperthermia between 39 °C and 40 °C, but they were attenuated by propofol with mild hyperthermia.


Assuntos
Hipertermia Induzida , Propofol/uso terapêutico , Choque Séptico/terapia , Acidose/sangue , Acidose/tratamento farmacológico , Acidose/etiologia , Acidose/terapia , Animais , Dióxido de Carbono/sangue , Terapia Combinada , Citocinas/sangue , Citocinas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Hemodinâmica , Hipotensão/tratamento farmacológico , Hipotensão/etiologia , Hipotensão/fisiopatologia , Hipotensão/terapia , Lipopolissacarídeos/toxicidade , Masculino , Oxigênio/sangue , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Choque Séptico/sangue , Choque Séptico/complicações , Choque Séptico/tratamento farmacológico , Choque Séptico/fisiopatologia
3.
Nat Mater ; 11(4): 323-8, 2012 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-22344326

RESUMO

High-T(c) cuprates, iron pnictides, organic BEDT and TMTSF, alkali-doped C(60), and heavy-fermion systems have superconducting states adjacent to competing states exhibiting static antiferromagnetic or spin density wave order. This feature has promoted pictures for their superconducting pairing mediated by spin fluctuations. Sr(2)RuO(4) is another unconventional superconductor which almost certainly has a p-wave pairing. The absence of known signatures of static magnetism in the Sr-rich side of the (Ca, Sr) substitution space, however, has led to a prevailing view that the superconducting state in Sr(2)RuO(4) emerges from a surrounding Fermi-liquid metallic state. Using muon spin relaxation and magnetic susceptibility measurements, we demonstrate here that (Sr,Ca)(2)RuO(4) has a ground state with static magnetic order over nearly the entire range of (Ca, Sr) substitution, with spin-glass behaviour in Sr(1.5)Ca(0.5)RuO(4) and Ca(1.5)Sr(0.5)RuO(4). The resulting new magnetic phase diagram establishes the proximity of superconductivity in Sr(2)RuO(4) to competing static magnetic order.

4.
Neuroscience ; 168(1): 18-30, 2010 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-20338223

RESUMO

Recent studies of the freshwater planarian Dugesia japonica have revealed fundamental mechanisms and unique aspects of neuroscience and neuroregeneration. Here, we identified the gene for planarian choline acetyltransferase (Djchat), which is essential for acetylcholine (ACh) biosynthesis. Immunofluorescence studies using anti-Dugesia japonica ChAT (DjChAT) antibody revealed that cholinergic neurons are widely distributed in the planarian nervous system, including the brain, ventral nerve cords, optic nerves, and pharyngeal nerve plexus. In order to investigate the function of cholinergic neurons in planarians, we used both pharmacological and RNA interference (RNAi) approaches. Administration of physostigmine (an acetylcholinesterase inhibitor) clearly elevated the amount of ACh, and then induced sudden muscle contraction behavior in a concentration-dependent manner. In addition, we found that pretreatment with tubocurarine (a muscle nicotinic ACh receptor antagonist) or atropine (a non-selective muscarinic ACh receptor antagonist), but not pretreatment with mecamylamine (a neural nicotinic ACh receptor antagonist), significantly extended the latency time for physostigmine-induced contraction behavior, suggesting that muscle nicotinic ACh receptors and muscarinic ACh receptors contribute to physostigmine-induced contraction behavior. We also confirmed that ACh biosynthesis ability and DjChAT-immunoreactivity were eliminated in Djchat(RNAi) planarians. Moreover, the decrease of the level of ACh induced by Djchat(RNAi) caused extension of the latency time for contraction behavior. Our findings support the possibility that the cholinergic functions of planarians are similar to those of vertebrates, suggesting that planarians are simple but useful model organisms for getting insight into the cholinergic nervous system in higher animals.


Assuntos
Colina O-Acetiltransferase/metabolismo , Músculos/fisiologia , Neurônios/fisiologia , Acetilcolina/metabolismo , Sequência de Aminoácidos , Animais , Colina O-Acetiltransferase/genética , Inibidores da Colinesterase/farmacologia , Clonagem Molecular , DNA Complementar/genética , Etiquetas de Sequências Expressas , Imunofluorescência , Dados de Sequência Molecular , Contração Muscular/efeitos dos fármacos , Músculos/efeitos dos fármacos , Neurônios/enzimologia , Filogenia , Fisostigmina/farmacologia , Planárias , Interferência de RNA , RNA Mensageiro/metabolismo , Receptores Colinérgicos/fisiologia
5.
J Neurosci Res ; 64(6): 553-63, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11398178

RESUMO

Glucocorticoid-attenuated response genes (GARG) belong to a recently described family of genes responsive to the action of dexamethasone. Full-length cDNA of one member of this family, GARG16, has been cloned from rat microglia and regulation of its mRNA expression has been studied. Moreover, regulation of retinoid/retinoic acid activated transcription factor (RXR/RAR) mRNAs in mixed astrocyte and in purified microglia cultures has been investigated. RARbeta mRNA was undetectable in microglia by RT-PCR, whereas clearly present in the mixed cultures. RXRalpha, RARgamma, and GARG16 mRNAs were found in both culture systems. RXRalpha mRNA was strongly expressed in control microglia but rapidly declined upon treatment with LPS. Conversely, GARG16 mRNA was almost untraceable in control microglia but rapidly increased by LPS. Time-course studies revealed an oscillating behavior of expression of both mRNAs during the first 6 hr, which receded to control levels (RXRalpha high, GARG16 low) at 72 hr of LPS-treatment. Additionally, p38 MAPK and SEK phosphorylations peaked at 1 hr followed by steady declines, whereas MEK and c-Jun showed double peaks at 1+4 hr and 1+6 hr, respectively, before subsiding to control levels. This behavior was not observed in comparative studies with TNF-alpha, interleukin-10 (IL-10), or interferon-gamma inducible protein 10 (IP-10). Finally, inhibitors of p38 MAPK, p42/p44 ERK, and PKCalpha as well as the use of dexamethasone revealed major influences of the p38 MAPK-c-Jun-AP-1 signaling pathway on RXRalpha and GARG16 mRNA expressions. The counter regulatory control of GARG16 and RXRalpha mRNA expression is believed to be an example of a fine-tuned cellular mechanism to react to inflammatory stimuli.


Assuntos
Lipopolissacarídeos/farmacologia , Microglia/fisiologia , Proteínas do Tecido Nervoso/genética , Receptores do Ácido Retinoico/genética , Fatores de Transcrição/genética , Animais , Astrócitos/citologia , Sequência de Bases , Células Cultivadas , Clonagem Molecular , Técnicas de Cocultura , DNA Complementar , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/fisiologia , Microglia/química , Microglia/citologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/análise , Periodicidade , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Mensageiro/análise , Ratos , Ratos Wistar , Receptores do Ácido Retinoico/análise , Receptores X de Retinoides , Homologia de Sequência de Aminoácidos , Transdução de Sinais/fisiologia , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/análise , Proteínas Quinases p38 Ativadas por Mitógeno
6.
Org Lett ; 3(5): 679-81, 2001 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-11259035

RESUMO

[structure: see text]. Two iridoid lactones, (-)-iridolactone and (+)-pedicularis-lactone, have been synthesized in an enantio- and diastereocontrolled manner starting from a tricyclic chiral building block serving as a synthetic equivalent of chiral 3-(hydroxymethyl)cyclopenta-2,4-dien-1-ol.


Assuntos
Iridoides , Lactonas/síntese química , Plantas Medicinais/química , Ásia , Indicadores e Reagentes , Estereoisomerismo
7.
Nihon Hoigaku Zasshi ; 55(3): 331-8, 2001 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-11905042

RESUMO

We investigated false-positive reactions obtained from a drug screening test using a Triage panel. We detected 2 cases giving false-positive reaction for AMP (amphetamine, methamphetamine) during the screening of 187 normal subjects. Subsequent follow up testing by high-performance liquid chromatography (HPLC), showed both to be false-positive reactions. As both cases have a history of ingesting the herbal drug, Ma-huang (Ephedra sinica (Ephedraceae)), containing ephedrine, we examined the relationship between false-positive reactions on Triage and Ma-huang. All urine samples collected from 7 healthy volunteers following administration of Ma-huang indicated AMP positive on Triage. Also a high ratio of AMP positives was observed in the patients who were administered Ma-huang-containing drugs at the hospital. However, none of them were identified as true-positives by HPLC or gas chromatography mass spectrometry (GC/MS) analysis. The extract of Ma-huang contained in herbal drugs, which otherwise contain neither amphetamine nor its derivatives, gives (AMP) positive indications on Triage. We speculate that unidentified components of Ma-huang cause the false-positive reactions. We suggest that follow-up tests by GC/MS or HPLC are needed wherever a positive result is obtained from a screening test by Triage. Furthermore, it will be established to continue collecting information on prescribed and non-prescribed drugs.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Ephedra sinica/química , Detecção do Abuso de Substâncias/métodos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão , Reações Falso-Positivas , Feminino , Humanos , Indóis/urina , Masculino , Pessoa de Meia-Idade
8.
Org Lett ; 2(20): 3193-5, 2000 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-11009379

RESUMO

A diastereocontrolled synthesis of (+)-febrifugine, a potent antimalarial piperidine alkaloid, has been achieved using a chiral block having a bicyclo[3.2.1]octane framework which exhibits inherent convex-face selectivity.


Assuntos
Alcaloides/síntese química , Antimaláricos/síntese química , Piperidinas/síntese química , Quinazolinas/síntese química , Plantas Medicinais/química , Estereoisomerismo
9.
Org Lett ; 2(18): 2757-9, 2000 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-10964358

RESUMO

An expedient route to the Calabar bean alkaloids (-)-physovenine and (-)-physostigmine has been devised using a chiral building block which was originally designed for diastereocontrolled construction of aldohexoses.


Assuntos
Inibidores da Colinesterase/síntese química , Fisostigmina/análogos & derivados , Fisostigmina/síntese química , Fabaceae/química , Plantas Medicinais , Estereoisomerismo
10.
Crit Care Med ; 28(4): 1101-6, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10809290

RESUMO

OBJECTIVE: To document the effects of propofol on the hemodynamic and inflammatory responses to endotoxemia in an animal model. DESIGN: Randomized, prospective laboratory study. SETTING: University experimental laboratory. SUBJECTS: Thirty-two male rats. INTERVENTIONS: The animals were randomly assigned to one of four groups: a) endotoxemia group (n = 8), which received intravenous Escherichia coli endotoxin (15 mg/kg over 2 mins); b) control group (n = 8), which was treated identically to the endotoxemia group except for the substitution of 0.9% saline for endotoxin; c) propofol group (n = 8), which was treated identically to the control group but also received propofol (10 mg/kg bolus, followed by infusion at 10 mg/kg/hr) immediately after the injection of 0.9% saline; and d) propofol-endotoxemia group (n = 8), which was treated identically to the endotoxemia group with the additional administration of propofol (10 mg/kg bolus, followed by infusion at 10 mg/kg/hr) immediately after endotoxin injection. MEASUREMENTS AND MAIN RESULTS: Hemodynamics, arterial blood gases, and acid-base status were recorded and the blood propofol concentrations and plasma cytokine concentrations were measured during the 5-hr observation. Microscopic findings of lung tissue for each group were obtained at necropsy. The systolic arterial pressure and heart rate of the propofol-endotoxemia group were similar to those of the endotoxemia group. The increases in the plasma cytokine (tumor necrosis factor, interleukin-6, and interleukin-10) concentrations, in the base deficit, and in the infiltration of neutrophils in the air space or vessel walls of the lungs were attenuated in the propofol-endotoxemia group compared with the endotoxemia group. CONCLUSIONS: Propofol attenuated cytokine responses, base deficit, and activation of neutrophils to endotoxemia. These findings suggest that propofol may inhibit inflammatory response and prevent the development of metabolic acidosis during endotoxemia.


Assuntos
Endotoxemia/tratamento farmacológico , Infecções por Escherichia coli/tratamento farmacológico , Hipnóticos e Sedativos/uso terapêutico , Propofol/uso terapêutico , Síndrome de Resposta Inflamatória Sistêmica/tratamento farmacológico , Animais , Avaliação Pré-Clínica de Medicamentos , Endotoxemia/sangue , Endotoxemia/patologia , Endotoxemia/fisiopatologia , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Hipnóticos e Sedativos/sangue , Hipnóticos e Sedativos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Propofol/sangue , Propofol/farmacologia , Estudos Prospectivos , Distribuição Aleatória , Ratos , Ratos Wistar , Síndrome de Resposta Inflamatória Sistêmica/sangue , Síndrome de Resposta Inflamatória Sistêmica/patologia , Síndrome de Resposta Inflamatória Sistêmica/fisiopatologia
11.
Br J Pharmacol ; 129(8): 1569-76, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10780960

RESUMO

Two splice isoforms of rabbit alpha(1a)-adrenergic receptor (AR), (named alpha(1a)-OCU.2-AR and alpha(1a)-OCU.3-AR) have been isolated from the liver cDNA library in addition to the previously reported isoform (alpha(1a)-OCU.1-AR). Although they have the identical splice position with human alpha(1a)-AR isoforms, the C-terminal sequences are distinct from those of human isoforms. Among these rabbit alpha(1a)-AR isoforms, there are no significant differences in pharmacological properties: high affinity for prazosin, WB4101, KMD-3213 and YM617 and low affinity for BMY7378, using COS-7 cells expressing each isoform by radioligand binding assay. Competitive reverse transcription-polymerase chain reaction (RT - PCR) analysis revealed that mRNA of alpha(1a)-ARs was expressed in liver, thoracic aorta, brain stem and thalamus of rabbit. The splice isoforms exhibited a distinct distribution pattern in rabbit; alpha(1a)-OCU. 1-AR was expressed most abundantly in those tissues. CHO clones, stably expressing each isoforms with receptor density 740 fmol mg(-1) protein in alpha(1a)-OCU.1-AR, 1200 fmol mg(-1) in alpha(1a)-OCU.2-AR and 570 fmol mg(-1) in alpha(1a)-OCU.3-AR, respectively, showed a noradrenaline-induced increase in inositol trisphosphate which was suppressed by prazosin. Noradrenaline elicited a concentration-dependent increase in extracellular acidification rate (EAR) in the CHO clones with pEC(50) values of 6. 19 for alpha(1a)-OCU.1-AR, 6.49 for alpha(1a)-OCU.2-AR and 6.58 for alpha(1a)-OCU.3-AR, respectively. Noradrenaline caused a concentration-dependent increase in intracellular Ca(2+) concentration ([Ca(2+)]i) in the CHO clones with pEC(50) values of 6. 14 for alpha(1a)-OCU.1-AR, 7.25 for alpha(1a)-OCU.2-AR and 7.70 for alpha(1a)-OCU.3-AR, respectively. In conclusion, the present study shows the occurrence of three splice isoforms of rabbit alpha(1a)-AR, which are unique in C-terminal sequence and in tissue distribution. They show similar pharmacological profiles in binding studies but alpha(1a)-OCU.3-AR had the highest potency of noradrenaline in functional studies in spite of the lowest receptor density. These findings suggest that the structure of C-terminus of alpha(1a)-ARs may give the characteristic functional profile.


Assuntos
Processamento Alternativo , Receptores Adrenérgicos alfa 1/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células CHO , Células COS , Cálcio/metabolismo , Clonagem Molecular , Cricetinae , DNA Complementar/análise , Biblioteca Gênica , Cobaias , Humanos , Inositol 1,4,5-Trifosfato/metabolismo , Dados de Sequência Molecular , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Coelhos , Ensaio Radioligante , Receptores Adrenérgicos alfa 1/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Distribuição Tecidual
12.
Ann Neurol ; 44(5): 796-807, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9818936

RESUMO

In this study, we analyzed the mechanism of selective motor neuronal death, a characteristic of amyotrophic lateral sclerosis, using embryonic rat spinal cord culture. When dissociated cultures were exposed to low-level glutamate (Glu) coadministered with the Glu transporter inhibitor L-trans-pyrrolidine-2,4-decarboxylate (PDC) for 24 hours, motor neurons were selectively injured through N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate receptors. Nitric oxide synthase (NOS) inhibitors attenuated this toxicity, and long-acting nitric oxide (NO) donors damaged motor neurons selectively. Nonmotor neurons survived after exposure to low-dose Glu/PDC, but Glu-induced toxicity was potentiated by coadministration of an NO-dependent guanylyl cyclase inhibitor. In addition, 8-bromo-cyclic GMP, a soluble cyclic GMP analogue, rescued nonmotor neurons, but not motor neurons, exposed to high-dose Glu/PDC. Twenty-four hours' incubation with PDC elevated the number of neuronal NOS-immunoreactive neurons by about twofold compared with controls, and a double-staining study, using the motor neuron marker SMI32, revealed that most of them were nonmotor neurons. These findings suggest that selective motor neuronal death caused by chronic low-level exposure to Glu is mediated by the formation of NO in nonmotor neurons, which inversely protects nonmotor neurons through the guanylyl cyclase-cyclic GMP cascade. Induction of neuronal NOS in nonmotor neurons might enhance both the toxicity of motor neurons and the protection of nonmotor neurons, which could explain the pathology of amyotrophic lateral sclerosis.


Assuntos
Morte Celular/fisiologia , Ácido Glutâmico/fisiologia , Neurônios Motores/citologia , N-Metilaspartato/toxicidade , Neurônios/citologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/fisiologia , Medula Espinal/citologia , Esclerose Lateral Amiotrófica , Animais , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , GMP Cíclico/análogos & derivados , GMP Cíclico/farmacologia , Ácidos Dicarboxílicos/farmacologia , Embrião de Mamíferos , Ácido Glutâmico/farmacologia , Modelos Neurológicos , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Inibidores da Captação de Neurotransmissores/farmacologia , Pirrolidinas/farmacologia , Ratos , Ratos Wistar
13.
Brain Res Mol Brain Res ; 59(2): 143-53, 1998 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-9729343

RESUMO

Distribution of mRNA encoding PKN, a fatty acid and RhoA-activated serine/threonine protein kinase with a catalytic domain highly homologous to that of protein kinase C, was investigated in the rat brain using in situ hybridization histochemistry. PKN mRNA proved to be heterogenously distributed. The highest signals were observed in the cerebellum, in limbic systems such as olfactory bulb, hippocampal formation and limbic cortex, and in regions involved in central autonomic and neuroendocrine functions, such as hypothalamic ventromedial, dorsomedial, lateroanterior and arcuate nuclei, paraventricular hypothalamic nucleus and locus coeruleus. PKN mRNA was also highly expressed in dopaminergic neurons such as the ventral tegmental area and substantia nigra pars compacta, in serotonergic raphe neurons, and in cholinergic neurons such as nucleus diagonal band, nucleus basalis, and lateral dorsal tegmental nucleus. The distribution of PKN mRNA differed from that for PKC isoforms. As the localization of PKN mRNA is heterogeneous, PKN may have a specific role in distinct populations of nerve cells.


Assuntos
Química Encefálica/fisiologia , Proteína Quinase C/genética , Animais , Northern Blotting , Cerebelo/química , Córtex Cerebral/química , Hipocampo/química , Hibridização In Situ , Masculino , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Tálamo/química
14.
Crit Care Med ; 24(4): 642-6, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8612417

RESUMO

OBJECTIVE: To assess the effects of lidocaine on the hemodynamic and inflammatory responses to Escherichia coli endotoxemia in rabbits. DESIGN: Prospective, randomized, controlled experimental study. SETTING: University laboratory. SUBJECTS: Twenty-seven female Japanese rabbits, anesthetized with urethane and ventilated mechanically. INTERVENTIONS: Animals were randomly assigned to one of three groups: a) endotoxemic control group (n = 9), receiving intravenous Escherichia coli endotoxin (0.5 mg/kg bolus) via the mesenteric vein; b) laparotomy control group (n = 9), treated identically to the endotoxemic control group, except for substitution of 0.9% saline for endotoxin; and c) lidocaine-treated group (n = 9), treated identically to the endotoxemic controls and additionally, intravenous lidocaine (3 mg/kg bolus, followed by infusion at 2 mg/kg/hr) was administered immediately after endotoxin MEASUREMENTS AND MAIN RESULTS: We compared hemodynamics, blood gases, and microscopic findings of lung tissue obtained at necropsy in each group. Laparotomy alone had a minimal effect on the parameters and findings. Endotoxin injection decreased mean systolic arterial pressure from 135 +/- 6 (SD) to 95 +/- 25 mm Hg (p < .05) and increased the mean base deficit from -1.2 +/- 1.8 to -14.4 +/- 4.2 mmol/L (p < .05), and caused the infiltration of neutrophils into the lungs. Lidocaine administration abolished the hypotension and attenuated the increase the base deficit to -9.5 +/- 2.1 mmol/L (p < .05) and the cellular infiltration in comparison with endotoxemic controls. CONCLUSIONS: Lidocaine attenuated the hemodynamic and inflammatory responses to endotoxemia in rabbits. Findings suggest that lidocaine administration may prevent the development of hypotension and metabolic acidosis during endotoxemia.


Assuntos
Endotoxinas/sangue , Escherichia coli , Hipotensão/tratamento farmacológico , Lidocaína/uso terapêutico , Pneumonia/tratamento farmacológico , Toxemia/tratamento farmacológico , Equilíbrio Ácido-Base/efeitos dos fármacos , Animais , Avaliação Pré-Clínica de Medicamentos , Feminino , Hemodinâmica/efeitos dos fármacos , Hipotensão/sangue , Hipotensão/etiologia , Hipotensão/patologia , Hipotensão/fisiopatologia , Laparotomia , Lidocaína/sangue , Pulmão/patologia , Pneumonia/sangue , Pneumonia/etiologia , Pneumonia/patologia , Pneumonia/fisiopatologia , Estudos Prospectivos , Coelhos , Distribuição Aleatória , Fatores de Tempo , Toxemia/sangue , Toxemia/complicações , Toxemia/patologia , Toxemia/fisiopatologia
15.
Immunity ; 2(1): 89-100, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7600304

RESUMO

The IL-2 receptor (IL-2R) consists of three subunits, the IL-2R alpha, IL-2R beta, and IL-2R gamma chains. The IL-2-induced proliferative signals emanate from the cytoplasmic domains of IL-2R beta and IL-2R gamma, but the nature and function of the signaling molecules that transmit these signals are not fully understood. Here, we report that Syk protein tyrosine kinase (PTK) is physically associated with IL-2R in peripheral blood lymphocytes. cDNA expression studies further revealed that this association is critical for the IL-2-induced activation of Syk PTK, which occurs primarily via the serine-rich region of the IL-2R beta chain, which is essential for proliferative signal transmission. Furthermore, we provide evidence that in the hematopoietic cell line, BAF-B03, the activation of Syk PTK results in the induction of the c-myc gene, an event critical for the cell proliferation. Thus, Syk PTK may be a critical integral member of the signaling molecules engaged by the IL-2R.


Assuntos
Precursores Enzimáticos/metabolismo , Regulação da Expressão Gênica , Linfócitos/enzimologia , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-myc/fisiologia , Receptores de Interleucina-2/metabolismo , Transdução de Sinais/fisiologia , Adulto , Animais , Anticorpos Monoclonais/imunologia , Linhagem Celular Transformada , Chlorocebus aethiops , DNA Complementar/genética , Ativação Enzimática , Genes myc , Células-Tronco Hematopoéticas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Ativação Linfocitária , Substâncias Macromoleculares , Camundongos , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Recombinantes de Fusão/metabolismo , Suínos , Quinase Syk , Transfecção
17.
J Neurochem ; 54(2): 526-32, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1967631

RESUMO

We studied [3H]N-[1-(2-thienyl)cyclohexyl]-3,4-piperidine [( 3H]TCP) binding to human frontal cortex obtained at autopsy from 10 histologically normal controls and eight histopathologically verified cases with Alzheimer-type dementia (ATD). Extensively washed membrane preparations were used to minimize the effects of endogenous substances. In ATD frontal cortex, the total concentration (Bmax) of [3H]TCP binding sites was significantly reduced by 40-50%. The apparent dissociation constant (KD) values showed no significant change. The reduction in binding capacity was also apparent in Triton X-100-treated membrane preparations, and there was a linear correlation between the number of [3H]TCP binding sites and that of N-methyl-D-aspartate (NMDA)-sensitive [3H]glutamate binding sites. [3H]TCP binding sites spared in ATD brains retained the affinity for the ligand and the reactivity to NMDA, L-glutamate, and glycine. These results suggest that the primary change in NMDA receptor-ion channel complex in ATD brains is the reduction of its number, possibly reflecting the loss of neurons bearing these receptor complexes, and that the functional linkage within the receptor complexes spared in ATD brains remains normal.


Assuntos
Doença de Alzheimer/metabolismo , Lobo Frontal/metabolismo , Fenciclidina/análogos & derivados , Ácido Aspártico/análogos & derivados , Ácido Aspártico/farmacologia , Sítios de Ligação , Glutamatos/farmacologia , Ácido Glutâmico , Humanos , Membranas/metabolismo , N-Metilaspartato , Fenciclidina/metabolismo , Valores de Referência
18.
Shinrigaku Kenkyu ; 60(3): 148-55, 1989 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-2601198

RESUMO

The purpose of this study was to examine whether experiences of musical instruments influence on discrimination of two-pure-tone simultaneous intervals. Fifteen experienced and 14 inexperienced subjects were asked to compare a standard stimulus with a comparison stimulus whose lower tone was varied from -4 Hz to +4 Hz, and to judge whether they were same or different. One single tone and four two-pure-tone simultaneous intervals, major second, major third, perfect fifth, and major seventh were used as stimuli. The results showed that the experienced subjects were generally more accurate and quicker in the task than the inexperienced subjects. It was suggested that a schema for discrimination of two-pure-tone simultaneous intervals was formed by exercises on musical instruments, and that the inexperienced subjects also had the schema to some extent.


Assuntos
Música , Discriminação da Altura Tonal , Estimulação Acústica , Adulto , Humanos
19.
Gan To Kagaku Ryoho ; 14(11): 3064-70, 1987 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-2960267

RESUMO

As a postoperative adjuvant chemotherapy for gastric cancer, we have administered a combination of NCS (Neocarzinostatin) and 5-FU (NF treatment method) and in this paper we have compiled the results obtained in patients who were treated for 5 years in an attempt to compare the 5-year survival rate with that of patients administered a combination of MMC and 5-FU (MF treatment group) and a control group administered no anticancer agents. As the selection of either NF or MF treatment was conducted on an annual basis, this study can be considered an historical controlled study. The results obtained are summarized as follows. On comparing the survival rate of the NF treatment group and the control group, the 5-year survival rate for all patients who underwent curative resection and all patients with histological stage III cancers and the curative resection PS (+) group, as well as the survival period of the non-resected patients, showed a statistically significant difference, indicating that the survival rate was higher in the NF group. On comparing the NF group and the MF group, although no statistically significant difference was observed between then based on a stratified analysis of all resected cases, histological stage differences and n.ps factors, etc., certain values tended to indicate a higher survival rate for the NF group. Moreover, the survival rate of the non-resected patients was more favorable in the NF group. These results confirm that NCS is useful for the treatment of stomach cancer and compares favorably with MMC. The appearance of side-effects was significantly lower in the NF group in comparison with the MF group and the number of patients who had to discontinue therapy was extremely low.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Zinostatina/administração & dosagem , Adulto , Idoso , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Mitomicina , Mitomicinas/administração & dosagem , Período Pós-Operatório , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/cirurgia
20.
J Neurochem ; 48(4): 1215-21, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3029330

RESUMO

Using ligand binding techniques, we studied beta-adrenergic receptor subtypes in brains obtained at autopsy from seven histologically normal controls and seven histopathologically verified cases with Alzheimer-type dementia (ATD). Inhibition of [3H]dihydroalprenolol [( 3H]DHA) binding by the selective beta 1 antagonist, metoprolol, results in nonlinear Hofstee plots, suggesting the presence of the two receptor subtypes in the human brain. The calculated ratios of beta 1/beta 2-adrenergic receptors in control brains are as follows: frontal cortex, 49:51; temporal cortex, 31:69; hippocampus, 66:34; thalamus, 23:77; putamen, 70:30; caudate, 48:52; nucleus basalis of Meynert (NbM), 43:57; cerebellar hemisphere, 25:75. Compared with the controls, total concentrations of beta-adrenergic receptors were significantly reduced only in the thalamus of the ATD brains. beta 1-Adrenergic receptor concentrations were significantly reduced in the hippocampus and increased in the NbM and cerebellar hemisphere, whereas beta 2-adrenergic receptor concentrations were significantly reduced in the thalamus, NbM, and cerebellar hemisphere and increased in the hippocampus and putamen of the ATD brains. These results suggest that beta 1- and beta 2-adrenergic receptors are present in the human brain and that there are significant changes in both receptor subtypes in selected brain regions in patients with ATD.


Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Receptores Adrenérgicos beta/metabolismo , Idoso , Idoso de 80 Anos ou mais , Cerebelo/metabolismo , Di-Hidroalprenolol/metabolismo , Feminino , Hipocampo/metabolismo , Humanos , Masculino , Metoprolol/farmacologia , Putamen/metabolismo , Receptores Adrenérgicos beta/efeitos dos fármacos , Lobo Temporal/metabolismo , Tálamo/metabolismo , Distribuição Tecidual
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