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1.
Nat Commun ; 12(1): 59, 2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33397949

RESUMEN

Superconductivity is among the most fascinating and well-studied quantum states of matter. Despite over 100 years of research, a detailed understanding of how features of the normal-state electronic structure determine superconducting properties has remained elusive. For instance, the ability to deterministically enhance the superconducting transition temperature by design, rather than by serendipity, has been a long sought-after goal in condensed matter physics and materials science, but achieving this objective may require new tools, techniques and approaches. Here, we report the transmutation of a normal metal into a superconductor through the application of epitaxial strain. We demonstrate that synthesizing RuO2 thin films on (110)-oriented TiO2 substrates enhances the density of states near the Fermi level, which stabilizes superconductivity under strain, and suggests that a promising strategy to create new transition-metal superconductors is to apply judiciously chosen anisotropic strains that redistribute carriers within the low-energy manifold of d orbitals.

2.
Nat Commun ; 11(1): 2597, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32444617

RESUMEN

The evolution of Sr2IrO4 upon carrier doping has been a subject of intense interest, due to its similarities to the parent cuprates, yet the intrinsic behaviour of Sr2IrO4 upon hole doping remains enigmatic. Here, we synthesize and investigate hole-doped Sr2-xKxIrO4 utilizing a combination of reactive oxide molecular-beam epitaxy, substitutional diffusion and in-situ angle-resolved photoemission spectroscopy. Upon hole doping, we observe the formation of a coherent, two-band Fermi surface, consisting of both hole pockets centred at (π, 0) and electron pockets centred at (π/2, π/2). In particular, the strong similarities between the Fermi surface topology and quasiparticle band structure of hole- and electron-doped Sr2IrO4 are striking given the different internal structure of doped electrons versus holes.

3.
4.
QJM ; 106(10): 909-14, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23696676

RESUMEN

BACKGROUND: It has not been fully elucidated whether antihypertensive medication adherence affects blood pressure (BP) control in hypertension cases. AIM: To investigate the association of adherence to antihypertensive drug regimens and BP control using data from the Combination Pill of Losartan Potassium and Hydrochlorothiazide for Improvement of Medication Compliance Trial (COMFORT) study. DESIGN: An observational analysis from a randomized controlled trial. METHODS: A total of 203 hypertensive subjects were randomly assigned to a daily regimen of a combination pill (losartan 50 mg/hydrochlorothiazide 12.5 mg) or two pills, an angiotensin II receptor blocker and a thiazide diuretic. Medication adherence calculated based on pill counts and BPs was evaluated at 1, 3 and 6 months after randomization. RESULTS: The subjects were divided into three groups according to their adherence, i.e. relatively low-adherence (<90%; n = 19), moderate-adherence (90-99%; n = 71) and high-adherence (100%; n = 113) groups. Clinical characteristics of the subjects including BP, sex, randomized treatments and past medical history did not differ significantly among the three groups. Achieved follow-up BPs over the 6-month treatment period, which were adjusted for age, sex, baseline BP and randomized treatment, were significantly higher in the low-adherence group (135/78 mmHg) compared with the high-adherence (130/74 mmHg; P = 0.02/0.02) and the moderate-adherence (128/74 mmHg; P = 0.003/0.02) groups. CONCLUSION: Low adherence to an antihypertensive-drug regimen was associated with poor BP control.


Asunto(s)
Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Cumplimiento de la Medicación , Anciano , Antihipertensivos/farmacología , Combinación de Medicamentos , Femenino , Humanos , Hidroclorotiazida/economía , Hidroclorotiazida/uso terapéutico , Hipertensión/fisiopatología , Japón/epidemiología , Losartán/economía , Losartán/uso terapéutico , Masculino , Persona de Mediana Edad , Educación del Paciente como Asunto , Estudios Prospectivos , Resultado del Tratamiento
5.
Br J Cancer ; 98(8): 1348-56, 2008 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-18362935

RESUMEN

The antitumour activity of a medicinal mushroom Phellinus linteus (PL), through the stimulation of immune system or the induction of apoptosis, has been recently described. However, the molecular mechanisms responsible for the inhibition of invasive behaviour of cancer cells remain to be addressed. In the present study, we demonstrate that PL inhibits proliferation (anchorage-dependent growth) as well as colony formation (anchorage-independent growth) of highly invasive human breast cancer cells. The growth inhibition of MDA-MB-231 cells is mediated by the cell cycle arrest at S phase through the upregulation of p27(Kip1) expression. Phellinus linteus also suppressed invasive behaviour of MDA-MB-231 cells by the inhibition of cell adhesion, cell migration and cell invasion through the suppression of secretion of urokinase-plasminogen activator from breast cancer cells. In addition, PL markedly inhibited the early event in angiogenesis, capillary morphogenesis of the human aortic endothelial cells, through the downregulation of secretion of vascular endothelial growth factor from MDA-MB-231 cells. These effects are mediated by the inhibition of serine-threonine kinase AKT signalling, because PL suppressed phosphorylation of AKT at Thr(308) and Ser(473) in breast cancer cells. Taken together, our study suggests potential therapeutic effect of PL against invasive breast cancer.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Polisacáridos/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Neoplasias de la Mama/irrigación sanguínea , Neoplasias de la Mama/patología , Capilares/efectos de los fármacos , Capilares/fisiología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Invasividad Neoplásica , Phellinus , Extractos Vegetales
6.
Acta Anaesthesiol Scand ; 51(9): 1237-44, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17850565

RESUMEN

BACKGROUND: Platelet activation is a critical step in primary hemostasis and clot formation. We tested a hypothesis that platelet stimulating effects of vasoactive agents or platelet agonists could be shown using thrombelastography (TEG) as faster onset or increased clot strength. We further examined if TEG could be modified to evaluate activated platelets as a reversal of anticoagulation in the presence of partial thrombin inhibition. METHODS: Blood samples were obtained from 126 non-cardiac surgical patients. Effects of vasoactive agents on TEG and aggregometry were examined using epinephrine, norepinephrine, vasopressin, desmopressin acetate, milrinone and olprinone (Experiment I). Platelet agonists (epinephrine, ADP and collagen) were separately tested on TEG (Experiment II). Effects of platelet agonists (ADP and collagen) on TEG under anticoagulation in the absence or presence of abciximab were studied (Experiment III). We also tested antiplatelet effects of milrinone and olprinone in the presence of anticoagulants on TEG (Experiment IV). RESULTS: Neither vasoactive agents nor platelet agonists affected TEG or aggregometry results except for milrinone and olprinone on aggregometry (Experiment I, II). Platelet agonists facilitated clotting in the presence of anticoagulants (Experiment III). Abciximab-treated platelets still exhibited procoagulant effects in the presence of heparin, while not in the presence of argatroban (Experiment III). Platelet inhibition on the modified TEG was more extensive with milrinone than olprinone, and it was dose dependent (Experiment IV). CONCLUSION: Modified TEG using heparin or argatroban might delineate the procoagulant effects of platelets by adding platelet specific agonist.


Asunto(s)
Anticoagulantes/farmacología , Plaquetas/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Adenosina Difosfato/fisiología , Plaquetas/fisiología , Cardiotónicos/farmacología , Colágeno/fisiología , Relación Dosis-Respuesta a Droga , Humanos , Inhibidores de Fosfodiesterasa/farmacología , Estadísticas no Paramétricas , Tromboelastografía/efectos de los fármacos , Vasoconstrictores/farmacología
7.
Br J Anaesth ; 92(2): 238-41, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14722176

RESUMEN

BACKGROUND: This study sought to determine the effective concentration for 50% of the attempts to secure laryngeal mask insertion (predicted EC(50LMA)) of propofol using a target-controlled infusion (Diprifusor) and investigated whether fentanyl influenced these required concentrations, respiratory rate (RR) and bispectral index (BIS). METHODS: Sixty-four elective unpremedicated patients were randomly assigned to four groups (n = 16 for each group) and given saline (control) or fentanyl 0.5, 1 or 2 micro g kg(-1). Propofol target concentration was determined by a modification of Dixon's up-and-down method. Laryngeal mask airway insertion was attempted without neuromuscular blocking drugs after equilibration had been established for >10 min. Movement was defined as presence of bucking or gross purposeful muscular movement within 1 min after insertion. EC(50LMA) values were obtained by calculating the mean of 16 patients in each group. RESULTS: Predicted EC(50LMA) of the control, fentanyl 0.5, 1 and 2 micro g kg(-1) groups were 3.25 (0.20), 2.06 (0.55), 1.69 (0.38) and 1.50 (0.54) micro g ml(-1) respectively; those of all fentanyl groups were significantly lower than that of control. RR was decreased in relation to the fentanyl dose up to 1 micro g kg(-1). BIS values after fentanyl 1 and 2 micro g kg(-1) were significantly greater than in the control and 0.5 micro g kg(-1) groups. CONCLUSIONS: A fentanyl dose of 0.5 micro g kg(-1) is sufficient to decrease predicted EC(50LMA) with minimum respiratory depression and without a high BIS value.


Asunto(s)
Adyuvantes Anestésicos/administración & dosificación , Anestésicos Intravenosos/administración & dosificación , Fentanilo/administración & dosificación , Máscaras Laríngeas , Propofol/administración & dosificación , Adulto , Analgésicos Opioides/administración & dosificación , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Electroencefalografía/efectos de los fármacos , Femenino , Hemodinámica/efectos de los fármacos , Humanos , Persona de Mediana Edad , Respiración/efectos de los fármacos
8.
Anaesthesia ; 57(10): 956-9, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12358953

RESUMEN

This study sought to determine the predicted Cp50 of propofol required for laryngeal mask airway insertion (Cp50LMA) and to investigate whether nitrous oxide reduces these required concentrations. Using target-controlled infusion and incorporating the standard Diprifusor pharmacokinetic model, 46 unpremedicated patients were randomly assigned to one of two groups. The patients received either 40% oxygen in air (control group: n = 23), or 60% nitrous oxide in oxygen (nitrous oxide group: n = 23). The target concentration for each patient was determined using the up and down method. Following equilibration between the predetermined blood and effect site concentrations, had been established for > 10 min, laryngeal mask airway insertion was attempted without neuromuscular relaxants. The data were analysed using a probit analysis to obtain Cp50LMA levels. The values for Cp50LMA were 3.24 micro g.ml-1 in the control group and 1.93 microg.ml-1 in the nitrous oxide group.


Asunto(s)
Anestésicos por Inhalación/farmacología , Anestésicos Intravenosos/sangre , Máscaras Laríngeas , Óxido Nitroso/farmacología , Propofol/sangre , Adolescente , Adulto , Anestésicos Combinados/sangre , Anestésicos Combinados/farmacología , Anestésicos Intravenosos/farmacología , Presión Sanguínea/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Procedimientos Quirúrgicos Ginecológicos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Intubación Intratraqueal/métodos , Modelos Logísticos , Persona de Mediana Edad , Propofol/farmacología
10.
Psychiatry Clin Neurosci ; 55(6): 619-22, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11737795

RESUMEN

Three cases involving a previously unreported association of acute pancreatic damage following convulsive status epilepticus (SE) are presented. A review of literature failed to reveal a similar association between SE and acute pancreatic damage. As possible pathophysiological mechanisms of this so far unknown sequel of SE, increased intraduodenal pressure during SE leading to the reflux of the duodenal contents into the pancreatic duct, along with altered metabolism of oxygen-derived free radicals during a prolonged seizure with hypoxia and ischemia resulting in acinar cell injury are suggested. We believe that SE should be considered as an additional risk factor of acute pancreatitis and that pancreatic enzymes should be monitored in patients who have prolonged seizures.


Asunto(s)
Epilepsia Tónico-Clónica/complicaciones , Pancreatitis/etiología , Estado Epiléptico/complicaciones , Enfermedad Aguda , Adulto , Duodeno/fisiología , Epilepsia Tónico-Clónica/fisiopatología , Femenino , Humanos , Hipoxia-Isquemia Encefálica/etiología , Masculino , Insuficiencia Multiorgánica , Pancreatitis/diagnóstico , Pancreatitis/metabolismo , Presión , Especies Reactivas de Oxígeno/metabolismo , Estado Epiléptico/fisiopatología
11.
Am J Physiol Heart Circ Physiol ; 281(5): H1835-62, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11668044

RESUMEN

Ion channels are regulated by protein phosphorylation and dephosphorylation of serine, threonine, and tyrosine residues. Evidence for the latter process, tyrosine phosphorylation, has increased substantially since this topic was last reviewed. In this review, we present a comprehensive summary and synthesis of the literature regarding the mechanism and function of ion channel regulation by protein tyrosine kinases and phosphatases. Coverage includes the majority of voltage-gated, ligand-gated, and second messenger-gated channels as well as several types of channels that have not yet been cloned, including store-operated Ca2+ channels, nonselective cation channels, and epithelial Na+ and Cl- channels. Additionally, we discuss the critical roles that channel-associated scaffolding proteins may play in localizing protein tyrosine kinases and phosphatases to the vicinity of ion channels.


Asunto(s)
Canales Iónicos/metabolismo , Transducción de Señal/fisiología , Tirosina/metabolismo , Animales , Humanos , Fosforilación
13.
J Neuropsychiatry Clin Neurosci ; 13(2): 243-7, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11449031

RESUMEN

The authors studied 52 patients who had undergone surgery because of intractable temporal lobe epilepsy. Investigation of postoperative psychiatric illnesses focused on psychotic disorder (293.81 and 293.82) and mood disorder (293.83) due to a general medical condition diagnosed according to DSM-IV criteria. Presurgically, two episodic psychotic syndromes, acute interictal and postictal psychosis, were defined operationally. A correlation was confirmed between presurgical acute interictal psychosis and postsurgical psychotic disorder, as well as between presurgical postictal psychosis and postsurgical mood disorder. An excellent final outcome for postoperative mood disorder in contrast to a less favorable one for psychotic disorder was also suggested.


Asunto(s)
Epilepsia del Lóbulo Temporal/cirugía , Trastornos del Humor/etiología , Complicaciones Posoperatorias/etiología , Trastornos Psicóticos/etiología , Enfermedad Aguda , Adulto , Epilepsia del Lóbulo Temporal/psicología , Femenino , Humanos , Masculino , Trastornos del Humor/diagnóstico , Trastornos del Humor/psicología , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/psicología , Psicocirugía/efectos adversos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Factores de Riesgo
14.
Seizure ; 10(3): 197-202, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11437619

RESUMEN

A long-term follow-up study of Lennox-Gastaut syndrome (LGS) ( > 10 years) was conducted with 38 patients with severe motor and intellectual disabilities (SMID) to clarify the relationship between the rapid development of dysphagia and epileptic seizures, and to elucidate the long-term evolution of LGS in patients with SMID. Those who showed a relatively favourable seizure outcome were compared to those with a poor seizure outcome. Poor seizure outcome correlated strongly with: (a) an early appearance of dysphagia and additional deterioration of the already retarded mental function; (b) a predominance of atypical absence seizures; and (c) persistent frequent epileptiform discharges during electroencephalographic evaluations. Neither age at seizure onset nor intelligence level at the time of the last examination was correlated with seizure prognosis. Further, seizure prognosis was not related to the aetiology of LGS. Repeated seizures apparently caused development of progressive epileptic encephalopathy, in addition to the underlying severe brain damage. Since development of dysphagia burdens an already severely handicapped patient with intensive medical care, efforts to reduce the seizures and design a long-term care plan are of great importance.


Asunto(s)
Trastornos de Deglución/etiología , Epilepsia/fisiopatología , Discapacidad Intelectual/etiología , Trastornos de la Destreza Motora/etiología , Adulto , Edad de Inicio , Preescolar , Progresión de la Enfermedad , Electroencefalografía , Epilepsia/complicaciones , Epilepsia/psicología , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Pronóstico , Índice de Severidad de la Enfermedad , Síndrome
15.
J Neurol Neurosurg Psychiatry ; 70(4): 541-3, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11254785

RESUMEN

To delineate rub epilepsy--a type of reflex epilepsy induced by prolonged or repetitive cutaneous stimulation in a circumscribed area of the body--three cases are presented, as well as one of tooth brushing epilepsy for comparison. In all three cases of rub epilepsy, cutaneous stimuli in a particular body area on the left side initially induced a sensory jacksonian march in the middle of, or in close vicinity to, the trigger zone, which led to subsequent unilateral tonic contractions with intact consciousness. By contrast, a motor jacksonian seizure without sensory aura was induced in the patient with tooth brushing epilepsy. A review of cases with rub epilepsy, including those in this paper, disclosed a striking consistency in clinical manifestations. The symptomatology of the induced seizures indicates a propagation of epileptic discharges from the postcentral gyrus to the supplementary motor area. Rub epilepsy is proposed as a separate clinical entity, clearly demarcated from other somatosensory evoked reflex epilepsies such as startle and tooth brushing epilepsy.


Asunto(s)
Encéfalo/fisiopatología , Epilepsia Refleja/etiología , Epilepsia Refleja/fisiopatología , Estimulación Física/efectos adversos , Piel/fisiopatología , Adulto , Electroencefalografía , Femenino , Humanos , Magnetoencefalografía , Masculino
16.
Am J Physiol Heart Circ Physiol ; 280(4): H1427-33, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11247750

RESUMEN

This review summarizes what is currently known about the role of integrins in the vascular myogenic response. The myogenic response is the rapid and maintained constriction of a blood vessel in response to pressure elevation. A role for integrins in this process has been suggested because these molecules form an important mechanical link between the extracellular matrix and the vascular smooth muscle cytoskeleton. We briefly summarize evidence for a general role of integrins in mechanotransduction. We then describe the integrin subunit combinations known to exist in smooth muscle and the vascular wall matrix proteins that may interact with these integrins. We then discuss the effects of integrin-specific peptides and antibodies on vascular tone and on calcium entry mechanisms in vascular smooth muscle. Because integrin function is linked to the cytoskeleton, we discuss evidence for the role of the cytoskeleton in determining myogenic responsiveness. Finally, we analyze evidence that integrin-linked signaling pathways, such as those involving protein tyrosine phosphorylation cascades and mitogen-activated protein kinases, are required for myogenic tone.


Asunto(s)
Integrinas/fisiología , Mecanorreceptores/fisiología , Músculo Liso Vascular/fisiología , Transducción de Señal/fisiología , Animales , Presión Sanguínea , Calcio/fisiología , Citoesqueleto/fisiología , Matriz Extracelular/fisiología , Humanos
17.
Epilepsia ; 42(1): 98-103, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11207792

RESUMEN

We sought to examine interictal psychoses based on the international epilepsy classification and DSM IV criteria, with special attention paid to epilepsy types as well as to subcategories of psychoses. One hundred thirty-two outpatients were studied, each with definite evidence of both epilepsy and interictal psychosis clearly demarcated from postictal psychosis. We compared them with 2,773 other epilepsy outpatients as a control. Risk factors for psychosis were examined within the temporal lobe epilepsy (TLE) group and the more extended group of symptomatic localization-related epilepsy. Further, nuclear schizophrenia and other nonschizophrenic psychotic disorders were compared. We confirmed a close correlation between TLE and interictal psychoses. Within the TLE group, only early epilepsy onset and a history of prolonged febrile convulsions were revealed to be significantly associated with interictal psychosis. Within the symptomatic localization-related epilepsy group, such parameters as complex partial seizures, autonomic aura, and temporal EEG foci were closely associated with psychoses. There was also a significant difference between groups as to ictal fear and secondary generalization. Whereas patients with early psychosis onset and a low intelligence quotient were overrepresented in the nuclear schizophrenia group, drug-induced psychosis and alternative psychosis were underrepresented. TLE proved to be preferentially associated with interictal psychoses. Within the TLE group, medial TLE in particular was found to be more closely associated with psychosis. Our data support the original postulation of Landolt, stating that alternative or drug-induced psychoses constitute a definite subgroup of interictal psychoses, which are different from chronic epileptic psychoses that simulate schizophrenia.


Asunto(s)
Epilepsia/clasificación , Trastornos Psicóticos/clasificación , Adolescente , Adulto , Atención Ambulatoria , Niño , Comorbilidad , Electroencefalografía/estadística & datos numéricos , Epilepsia/diagnóstico , Epilepsia/epidemiología , Epilepsia del Lóbulo Temporal/clasificación , Epilepsia del Lóbulo Temporal/diagnóstico , Epilepsia del Lóbulo Temporal/epidemiología , Femenino , Humanos , Masculino , Prevalencia , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Psicometría , Psicosis Inducidas por Sustancias/clasificación , Psicosis Inducidas por Sustancias/diagnóstico , Psicosis Inducidas por Sustancias/epidemiología , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Esquizofrenia/clasificación , Esquizofrenia/diagnóstico , Esquizofrenia/epidemiología , Convulsiones Febriles/clasificación , Convulsiones Febriles/diagnóstico , Convulsiones Febriles/epidemiología , Terminología como Asunto
18.
Masui ; 49(9): 1011-4, 2000 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-11025957

RESUMEN

Two extremely-low-birth-weight infants, weighing each 684 and 975 g at birth, underwent emergency surgery because of ileus. Our previous experience with an extremely low birth weight infant, whose hemodynamic control during the surgery had been difficult without administering extra preoperative fluid and transfusion, made us administer enough fluid and transfusion during operation although their urine output was more than 2 ml.kg-1.hr-1. We gave intravenous volume to the present 2 cases before the operations despite the level of preoperative urine output and made their hemodynamic situation more stable during surgeries. We conclude it is very important to administer some amounts of intravenous volume (approximately 8-12 ml.kg-1.hr-1) in extremely low birth weight infants for emergency surgery with ileus regardless of their preoperative urine output.


Asunto(s)
Anestesia/métodos , Recién Nacido de Bajo Peso , Obstrucción Intestinal/cirugía , Transfusión Sanguínea , Urgencias Médicas , Fluidoterapia , Humanos , Lactante , Recién Nacido , Masculino , Atención Perioperativa , Resultado del Tratamiento
19.
Epilepsia ; 41(8): 1036-8, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10961632

RESUMEN

We report on a family having partial epilepsy with simple inheritance. The affected members commonly have aphasic episodes with secondary generalization; onset occurred either in adolescence or adulthood. Patients' response to medication has varied greatly. No neurological defects or decline in intelligence were found. The case represents another variety of rare familial partial epilepsy with neocortical epilepsy features.


Asunto(s)
Epilepsias Parciales/epidemiología , Epilepsias Parciales/genética , Familia , Síndrome de Landau-Kleffner/epidemiología , Síndrome de Landau-Kleffner/genética , Adolescente , Adulto , Edad de Inicio , Diagnóstico Diferencial , Electroencefalografía , Epilepsias Parciales/diagnóstico , Femenino , Predisposición Genética a la Enfermedad , Humanos , Síndrome de Landau-Kleffner/diagnóstico , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neocórtex/fisiopatología , Linaje
20.
Br J Pharmacol ; 131(1): 115-23, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10960077

RESUMEN

The mechanisms of the thapsigargin (TG)-induced capacitative Ca(2+) entry in in situ endothelial cells and its role in the regulation of arterial tone were investigated using front-surface fluorimetry and fura-2-loaded strips of porcine aortic valve and coronary artery. In the presence of extracellular Ca(2+), TG induced an initial rapid and a subsequent sustained elevation of cytosolic Ca(2+) concentration ([Ca(2+)](i)) in valvular strips. In the absence of extracellular Ca(2+), TG induced only a transient increase in [Ca(2+)](i). The TG-induced sustained elevation of [Ca(2+)](i) in endothelial cells was inhibited completely by 1 mM Ni(2+) and partly by 10 microM econazole and 30 microM ML-9, but not by 900 ng ml(-1) pertussis toxin or 100 microM wortmannin. Therefore, cytochrome P450 and protein phosphorylation are suggested to be involved in the TG-induced Ca(2+) influx in in situ endothelial cells. TG induced an endothelium-dependent large relaxation consisting of an initial and a late sustained relaxation in coronary arterial strip precontracted with U46619 (a thromboxane A2 analogue). Indomethacin alone had no effect, while indomethacin plus N(omega)-nitro-L-arginine (L-NOARG) markedly inhibited the sustained phase and slightly inhibited the initial phase of the TG-induced relaxation. TG induced a smaller but sustained relaxation during the 40 mM K(+)-induced precontraction than that seen during the U46619-induced precontraction. This relaxation was completely abolished by the pretreatment with indomethacin plus L-NOARG. In conclusion, both nitric oxide (NO) and endothelium-derived hyperpolarizing factor were suggested to mediate the TG-induced relaxation, while NO plays a major role in the sustained relaxation. The TG-induced sustained [Ca(2+)](i) elevation in endothelial cells was thus suggested to be mainly linked to the sustained production of NO.


Asunto(s)
Válvula Aórtica/efectos de los fármacos , Calcio/metabolismo , Vasos Coronarios/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Tapsigargina/farmacología , Vasodilatación/efectos de los fármacos , Animales , Válvula Aórtica/metabolismo , Factores Biológicos/fisiología , Vasos Coronarios/fisiología , Endotelio Vascular/fisiología , Técnicas In Vitro , Óxido Nítrico/fisiología , Óxido Nítrico Sintasa/fisiología , Nitroarginina/farmacología , Potasio/farmacología , Porcinos , Vasoconstricción/efectos de los fármacos
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