Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Prenat Diagn ; 27(11): 1045-55, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17729373

RESUMO

OBJECTIVE: To determine the attitudes of pediatric residents and nurses towards fetal/neonatal management of hypoplastic left heart syndrome (HLHS), and their basis. METHODS: Pediatric residents and nurses from three cardiac centers completed a survey with hypothetical scenarios in which their own fetuses or newborns had HLHS. While Institution A performs many HLHS surgeries, Institution C performs very few. RESULTS: A total of 43% of residents and 50% of nurses would terminate an affected pregnancy. More experience (4 to 7 years, p = 0.04; >7 years, p = 0.05) and employment at institution C (p = 0.04) predicted termination. Expected better quality of life (QOL) (p = 0.02) and five-year survival >50% (p = 0.06) predicted not terminating. Postnatally, 48% of residents and 68% of nurses would choose, or seriously consider, comfort care. Marriage (p = 0.04) and more experience (4 to 7 years, p = 0.04; >7 years, p = 0.02) predicted choosing comfort care. Asian/Pacific Islander descent (p = 0.01) and expected 5-year survival >50% (p = 0.02) predicted choosing surgery. CONCLUSIONS: Approximately one-half of the pediatric residents and nurses surveyed would choose termination of pregnancy or seriously consider declining neonatal surgery, if their own fetus or infant had HLHS. These attitudes reflect perceptions of long-term QOL and survival. These attitudes may be of interest to caregivers who care for HLHS patients.


Assuntos
Atitude do Pessoal de Saúde , Síndrome do Coração Esquerdo Hipoplásico/psicologia , Síndrome do Coração Esquerdo Hipoplásico/terapia , Cuidado do Lactente/psicologia , Internato e Residência , Enfermeiras e Enfermeiros , Cuidado Pré-Natal , Aborto Eugênico/psicologia , Estudos Transversais , Tomada de Decisões , Feminino , Humanos , Síndrome do Coração Esquerdo Hipoplásico/diagnóstico , Recém-Nascido , Masculino , Enfermeiras e Enfermeiros/psicologia , Pais/psicologia , Percepção , Gravidez , Fatores Socioeconômicos , Inquéritos e Questionários
2.
J Biol Chem ; 274(36): 25842-8, 1999 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-10464325

RESUMO

Mitogen-activated protein kinase (MAPK) activation provides cell type-specific signals important for cellular differentiation, proliferation, and survival. Cyclic AMP (cAMP) has divergent effects on MAPK activity depending on whether signaling is through Ras/Raf-1 or Rap1/B-raf. We found that central nervous system-derived neurons, but not astrocytes, express B-raf. In neurons, cAMP activated MAPK in a Rap1/B-raf-dependent manner, while in astrocytes, cAMP decreased MAPK activity. Inhibition of MAPK in neurons decreased neuronal growth factor-mediated survival, and activation of MAPK by cAMP analogues rescued neurons from death. Furthermore, constitutive expression of B-raf in astrocytoma cells increased MAPK activation, as seen in neurons, and enhanced proliferation. These data provide the first experimental evidence that B-raf is the molecular switch which dominantly permits differential cAMP-dependent regulation of MAPK in neurons versus astrocytes, with important implications for both survival and proliferation.


Assuntos
Astrócitos/metabolismo , AMP Cíclico/metabolismo , Neurônios/metabolismo , Transdução de Sinais , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Células Cultivadas , Proteínas de Ligação ao GTP/metabolismo , Camundongos , Especificidade de Órgãos , Proteínas Proto-Oncogênicas c-raf/metabolismo , Proteínas rap de Ligação ao GTP
3.
Brain Res ; 826(2): 172-80, 1999 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10224294

RESUMO

This study examined the effect of a pharmacologically induced rightward shift in the partial pressure of oxygen at which 50% of hemoglobin is saturated (P50) on outcome from transient focal cerebral ischemia in the rat. Halothane anesthetized rats (n=20 per group) were given saline or a single 15-min infusion of 150 mg/kg RSR13 (2-[4-[[3,5-dimethylanilino) carbonyl]methyl]phenoxy]-2-methylproprionic acid) intravenously before or 30 min after onset of 75 min of middle cerebral artery filament occlusion (MCAO). Seven days later, severity of hemiparesis and cerebral infarct size were examined. RSR13 alone did not significantly improve outcome. Conscious normothermic rats (n=12 per group) were also given RSR13 (150 mg/kg) or 0.9% NaCl intravenously and subjected to 75 min of MCAO with 7 days of recovery. Again, RSR13 alone did not significantly reduce infarct size or improve neurologic score. A dose-response curve for dizocilpine (MK-801) was then constructed in conscious normothermic rats subjected to 75 min of MCAO. Dizocilpine (0.5 mg/kg i.v.) caused a 90% reduction in mean infarct size while 0.25 mg/kg reduced infarct size by 48%. Other rats were then subjected to 75 min of MCAO after being given dizocilpine (0.25 mg/kg i.v.; n=18) or RSR13 (150 mg/kg i.v. )+dizocilpine (0.25 mg/kg i.v.; n=15). RSR13+dizocilpine resulted in smaller cortical infarct volume (8+/-14 mm3 vs. 34+/-37 mm3, p<0.02) and total cerebral infarct volume (46+/-28 mm3 vs. 81+/-60 mm3, p<0. 05) compared to dizocilpine alone, respectively. We conclude that a pre-ischemic peak increase in P50 of approximately 25 mmHg alone is insufficient to reduce focal ischemic injury, but may be advantageous when used in conjunction with other neuroprotective agents.


Assuntos
Compostos de Anilina/farmacologia , Antidrepanocíticos/farmacologia , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hemoglobinas/efeitos dos fármacos , Ataque Isquêmico Transitório/tratamento farmacológico , Propionatos/farmacologia , Sítio Alostérico/efeitos dos fármacos , Animais , Gasometria , Temperatura Corporal , Química Encefálica/efeitos dos fármacos , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/patologia , Infarto Cerebral/tratamento farmacológico , Infarto Cerebral/patologia , Quimioterapia Combinada , Hemoglobinas/química , Ataque Isquêmico Transitório/patologia , Masculino , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores
4.
Am J Emerg Med ; 17(2): 163-71, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10102319

RESUMO

Five cases of children with cerebrovascular disease presentations to the emergency department (ED) were selected as a series to illustrate the variety of presentation of cerebrovascular disease in children. This series shows that although cerebrovascular disease in children is uncommon, it is likely that cases will occasionally present acutely to an ED. The emergency physician's role in the management of suspected acute strokes in children is that of immediate stabilization, imaging to rule out hemorrhage, other studies to rule out emergent acute disease, and timely consultation for further management. Computed tomography (CT) is useful to detect an acute hemorrhage or old ischemic lesion. Magnetic resonance imaging has superior image resolution over CT, but CT may be more practical initially. Magnetic resonance angiography is a useful part of the stroke workup in children.


Assuntos
Transtornos Cerebrovasculares/diagnóstico , Emergências , Encéfalo/patologia , Angiografia Cerebral , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/etiologia , Ventrículos Cerebrais/patologia , Transtornos Cerebrovasculares/etiologia , Criança , Pré-Escolar , Diagnóstico Diferencial , Serviço Hospitalar de Emergência , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
5.
Anesth Analg ; 88(4): 787-92, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10195525

RESUMO

UNLABELLED: We postulated that adrenergic responses to global cerebral ischemia are anesthetic-dependent and similar in both brain and arterial blood. Rats were anesthetized with isoflurane (1.4%), ketamine (1 mg x kg(-1) x min(-1)), or fentanyl (25 microg x kg(-1) x h(-1))/70% N2O. The carotid arteries were occluded for either 20 min with mean arterial pressure (MAP) 50 mm Hg (incomplete ischemia) or 10 min with MAP 30 mm Hg (near-complete ischemia). Norepinephrine was measured in hippocampal microdialysate. Norepinephrine and epinephrine were measured in arterial plasma. In both hippocampus and plasma, basal norepinephrine was similar among anesthetics. During incomplete ischemia, hippocampal norepinephrine was twofold greater with fentanyl/N2O than with isoflurane (P = 0.037), but plasma norepinephrine and epinephrine were similar and unchanged among all three anesthetics. During near-complete ischemia, hippocampal norepinephrine was threefold greater with ketamine than fentanyl/N2O (P = 0.005), whereas plasma norepinephrine and epinephrine were markedly greater with fentanyl/N2O than with ketamine (P < 0.0005) or isoflurane (P = 0.05). There was no correlation between norepinephrine concentrations in hippocampus and plasma for either incomplete or near-complete ischemia. This study demonstrates that adrenergic responses to global ischemia are anesthetic-dependent, particularly during more severe insults. The absence of a correlation between plasma and brain catecholamine concentrations indicates that adrenergic responses to ischemia are independent in brain and blood. IMPLICATIONS: It has been proposed that anesthetics modulate cerebral ischemic outcome by influencing peripheral adrenergic responses to ischemia. This experiment demonstrates that anesthetics differentially modulate adrenergic responses to ischemia but that effects in plasma and brain are independent. This suggests that events detected in the peripheral circulation do not implicate direct mechanisms of action of catecholamines at the neuronal/glial level.


Assuntos
Anestésicos Inalatórios/farmacologia , Anestésicos Intravenosos/farmacologia , Isquemia Encefálica/metabolismo , Catecolaminas/sangue , Fentanila/farmacologia , Hipocampo/efeitos dos fármacos , Isoflurano/farmacologia , Ketamina/farmacologia , Óxido Nitroso/farmacologia , Animais , Isquemia Encefálica/sangue , Isquemia Encefálica/etiologia , Hipocampo/metabolismo , Masculino , Microdiálise , Ratos , Ratos Sprague-Dawley
6.
Neuroscience ; 88(1): 185-91, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10051199

RESUMO

Transgenic mice, which had been transfected with the human extracellular superoxide dismutase gene, causing an approximate five-fold increase in brain parenchymal extracellular superoxide dismutase activity, were used to investigate the role of extracellular superoxide dismutase in ischemic brain injury. Transgenic (n = 21) and wild-type (n = 19) mice underwent 90 min of intraluminal middle cerebral artery occlusion and 24 h of reperfusion. Severity of resultant hemiparesis and cerebral infarct size were measured. Wild-type mice had larger infarcts (cortex: wild type =37+/-14 mm3, transgenic = 27+/-13 mm3, P=0.03; subcortex: wild type = 33+/-14 mm3, transgenic = 23+/-10 mm3, P = 0.02). Neurological scores, however, were similar (P = 0.29). Other mice underwent autoradiographic determination of intra-ischemic cerebral blood flow. The volume of tissue at risk of infarction (defined as volume of tissue where blood flow was <25 ml/100g/min) was similar between groups (cortex: wild type = 51+/-15 mm3, transgenic = 47+/-9 mm3, P=0.65; subcortex: wild type = 39+/-16 mm3, transgenic= 37+/-17 mm3, P=0.81). These results indicate that antioxidant scavenging of free radicals by extracellular superoxide dismutase plays an important role in the histological response to a focal ischemic brain insult.


Assuntos
Infarto Cerebral/prevenção & controle , Hemiplegia/prevenção & controle , Ataque Isquêmico Transitório/fisiopatologia , Superóxido Dismutase/genética , Animais , Pressão Sanguínea , Temperatura Corporal , Infarto Cerebral/patologia , Circulação Cerebrovascular , Círculo Arterial do Cérebro/anormalidades , Círculo Arterial do Cérebro/anatomia & histologia , Lateralidade Funcional , Hematócrito , Hemiplegia/fisiopatologia , Humanos , Imunidade Inata/genética , Ataque Isquêmico Transitório/genética , Ataque Isquêmico Transitório/patologia , Masculino , Camundongos , Camundongos Transgênicos , Fatores de Risco , Superóxido Dismutase/metabolismo
7.
Neuroreport ; 9(11): 2615-20, 1998 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-9721943

RESUMO

Apolipoprotein E-(apoE) deficient mice exhibit hypercholesterolemia, accelerated atherosclerosis and increased infarct size after middle cerebral artery occlusion (MCAO). This study examined whether worsened ischemic outcome is attributable to effects of apoE deficiency on cerebral circulation. Wild type and apoE-deficient mice underwent MCAO and autoradigraphic measurement of cerebral blood flow. Circle of Willis anatomy was examined in non-ischemic animals. Both groups exhibited similar reduction in blood flow. Both groups had 100% incidence of filling of the anterior communicating artery. The posterior communicating artery (PcomA) filled in 70% of wild type and 80% of apoE-deficient mice. Both groups had considerable variability in relative sizes of the PcmA. This study indicates that worsened outcome from MCAO of apoE-deficient mice is not attributable to any detectable vascular effects and offers validity to use of apoE-deficient mice for study of apoE as a factor in cerebral ischemic pathophysiology.


Assuntos
Apolipoproteínas E/deficiência , Isquemia Encefálica/fisiopatologia , Circulação Cerebrovascular/fisiologia , Animais , Apolipoproteínas E/genética , Encéfalo/patologia , Isquemia Encefálica/genética , Isquemia Encefálica/patologia , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
8.
Anesthesiology ; 89(2): 391-400, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9710398

RESUMO

BACKGROUND: It has been postulated that anesthetic agents that reduce cerebral metabolic rate will protect the brain against ischemia when electroencephalographic (EEG) activity is persistent, but will provide no protection when ischemia is severe enough to cause EEG isoelectricity. No outcome studies have addressed this issue. The authors studied anesthetic agents to determine if they provide differential effects on outcome from global cerebral ischemic insults that cause either an attenuated or isoelectric EEG. METHODS: Fasted rats were subjected to either (1) incomplete ischemia (attenuated EEG; 20 min of mean arterial pressure [MAP] = 50 mmHg and bilateral carotid occlusion) or (2) near-complete ischemia (isoelectric EEG; 10 min of MAP = 30 mmHg and bilateral carotid occlusion) while anesthetized with 1.4% isoflurane, 1 mg x kg(-1) x min(-1) ketamine, or 25 microg x kg(-1) x h(-1) 70% nitrous oxide and fentanyl. The brain was maintained at normothermia during ischemia and for 22 h after ischemia. Five days later, hippocampal CA1 and cortical injury were measured. RESULTS: There was no difference among anesthetic agents during incomplete ischemia for mean +/- SD percentage dead CA1 neurons (fentanyl, 38%+/-20%; isoflurane, 31%+/-10%; ketamine, 40%+/-19%; P = 0.38). During near-complete ischemia, there was a difference among anesthetic agents (fentanyl, 88%+/-9%; isoflurane, 37%+/-20%; ketamine, 70%+/-28%; P = 0.00008). Isoflurane was protective compared with fentanyl (P = 0.00007) and ketamine (P = 0.0061). There was no difference between fentanyl and ketamine (P = 0.143). Similar observations were made in the cortex. Neurologic function correlated with histologic damage. CONCLUSIONS: Outcome from near-complete but not incomplete cerebral ischemia depended on the anesthetic agent administered during the ischemic insult.


Assuntos
Anestésicos/uso terapêutico , Isquemia/tratamento farmacológico , Anestesia , Anestésicos Inalatórios/farmacologia , Animais , Gasometria , Pressão Sanguínea/efeitos dos fármacos , Calibragem , Eletroencefalografia/efeitos dos fármacos , Halotano/farmacologia , Masculino , Neurônios Motores/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
9.
Stroke ; 29(8): 1650-5, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9707208

RESUMO

BACKGROUND AND PURPOSE: Neuronal injury results from an insufficient supply of oxygen to the brain. This experiment examined whether a pharmacologically induced rightward shift of the partial pressure of oxygen at which 50% of hemoglobin is saturated (P50) would improve outcome from either incomplete and/or near-complete forebrain ischemia-induced hypoxia in the rat. METHODS: For incomplete ischemia (attenuated electroencephalogram), fasted rats (n = 17 to 19 per group) were given a synthetic allosteric modifier of hemoglobin affinity for oxygen (RSR13; 150 mg/kg IV) before or immediately after 20 minutes of bilateral carotid occlusion combined with a decrease in mean arterial pressure to 40 mm Hg. For near-complete ischemia (isoelectric electroencephalogram), rats (n = 15 per group) were given RSR13 (150 mg/kg) at onset of reperfusion after 10 minutes of bilateral carotid occlusion combined with a decrease in mean arterial pressure to 30 mm Hg. In both experiments, control rats were given vehicle (0.9% NaCl IV) only. Outcome (defined as percent dead hippocampal CA1 neurons) was determined at 5 days after ischemia. RESULTS: RSR13 (150 mg/kg) produced a 68% rightward shift of P50 (34+/-3 to 57+/-8 mm Hg). RSR13 reduced CA1 damage resulting from incomplete ischemia by 28% (P=0.02), but only when administered at the onset of reperfusion. RSR13 had no effect on outcome from near-complete ischemia. CONCLUSIONS: A postischemic pharmacologically induced increase in P50 may improve outcome from incomplete global cerebral ischemia. More severe (near-complete) ischemia negates this benefit.


Assuntos
Compostos de Anilina/farmacologia , Antidrepanocíticos/farmacologia , Isquemia Encefálica/tratamento farmacológico , Oxigênio/sangue , Oxiemoglobinas/metabolismo , Propionatos/farmacologia , Regulação Alostérica , Animais , Isquemia Encefálica/metabolismo , Circulação Cerebrovascular/efeitos dos fármacos , Reagentes de Ligações Cruzadas/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Masculino , Oxiemoglobinas/química , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Resultado do Tratamento
10.
Anesthesiology ; 88(5): 1266-73, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9605687

RESUMO

BACKGROUND: The authors postulated that hypothermic neuroprotection can be attributed to a delayed onset of ischemic depolarization. METHODS: Halothane-anesthetized rats were prepared for near-complete forebrain ischemia. Direct current (DC) potential microelectrodes were placed in hippocampal CA1. The pericranial temperature was maintained at 31 degrees C, 33 degrees C, 35 degrees C, or 37 degrees C (n = 6 per group). Bilateral carotid occlusion with systemic hypotension was initiated for 10 min. The time to onset of the DC shift was recorded. In a second experiment, rats were assigned to 37 degrees C or 31 degrees C for 10 min of ischemia, or to 31 degrees C for 14 min of ischemia (n = 8 per group). These durations of ischemia were defined to allow 9 min of ischemic depolarization in the 37 degrees C-10 min and 31 degrees C-14 min groups. Neurologic and histologic outcomes were examined 7 days later. RESULTS: Hippocampal CA1 time to depolarization increased with decreasing temperature (P < 0.0001). Time to depolarization was increased by approximately 4 min in the rats maintained at 31 degrees C compared with those at 37 degrees C. Time to repolarization during reperfusion was not affected by temperature. Increasing the duration of ischemia from 10 min to 14 min with the pericranial temperature maintained at 31 degrees C resulted in a duration of depolarization that was equivalent in the 37 degrees C-10 min and 31 degrees C-14 min groups. However, hippocampal CA1 damage was not increased (31 degrees C-10 min = 4 +/- 1% dead neurons; 31 degrees C-14 min = 6 +/- 1% dead neurons, 95% CI, -1% to 3%; 37 degrees C-10 min = 90 +/- 17% dead neurons). CONCLUSIONS: Despite similar durations of DC depolarization, outcome in hypothermic rats was markedly improved compared with normothermic rats. This indicates that hypothermic neuroprotection can be attributed to mechanisms other than the delay in time to onset of ischemic depolarization.


Assuntos
Isquemia Encefálica/fisiopatologia , Hipocampo/fisiologia , Hipotermia/fisiopatologia , Animais , Estimulação Elétrica , Eletroencefalografia , Hemodinâmica , Hipocampo/patologia , Masculino , Potenciais da Membrana , Ratos , Ratos Sprague-Dawley
11.
J Cereb Blood Flow Metab ; 18(4): 361-6, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9538900

RESUMO

Apolipoprotein E (apoE), a 34-KD glycosylated lipid-binding protein, is expressed as three common isoforms in humans (E2, E3, or E4). Clinical evidence suggests that the apoE genotype (APOE) may be a risk factor for poor outcome after acute central nervous system injury. This was examined further in transgenic mice constructed with the human APOE3 or APOE4 gene under the control of human promoter and tissue expression elements. Presence of human apoE3 and apoE4 proteins in brains of human APOE homozygous transgenic mice was confirmed by Western blotting. APOE3 (n = 12) and APOE4 (n = 10) mice underwent 60 minutes of middle cerebral artery occlusion. After 24-hour recovery, infarct size was measured. Infarct volumes (mean +/- standard deviation) were smaller in the APOE3 group (cortex: APOE3 = 18 +/- 4 mm3; APOE4 = 30 +/- 11 mm3, P = 0.04; subcortex: APOE3 = 12 +/- 4 mm3; APOE4 = 18 +/- 4 mm3, P = 0.003). Hemiparesis was less severe in APOE3 mice (P = 0.02). These data indicate that human isoform-specific effects of apoE are relevant to acute pathomechanisms of focal ischemic brain damage when examined in the mouse. APOE transgenic mice may provide an appropriate model to examine the mechanistic basis for the differential effects of human apoE isoforms in acute central nervous system injury.


Assuntos
Apolipoproteínas E/genética , Isquemia Encefálica/metabolismo , Alelos , Animais , Apolipoproteína E3 , Apolipoproteína E4 , Apolipoproteínas E/classificação , Apolipoproteínas E/fisiologia , Western Blotting , Isquemia Encefálica/complicações , Isquemia Encefálica/patologia , Infarto Cerebral/etiologia , Infarto Cerebral/patologia , Genótipo , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Especificidade da Espécie
12.
Brain Res ; 779(1-2): 170-6, 1998 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9473659

RESUMO

Glycine is a requisite cofactor for glutamatergic activation of the N-methyl-D-aspartate (NMDA) receptor. Antagonism of glutamate at the NMDA receptor has been shown to cause substantial changes in regional cerebral metabolic rate for glucose utilization (CMRglu) and blood flow (CBF). This study examined CMRglu and CBF changes caused by antagonism of glycine at the NMDA receptor recognition site. Rats were anesthetized with halothane and vascular access was obtained. The animals were then awakened. One hour later, either vehicle (control) or ACEA 1021 (5 mg/kg followed by 3.5 mg x kg(-1) x h(-1) or 10 mg/kg followed by 7 mg x kg(-1) x h(-1)) was infused intravenously. CMRglu and CBF were then determined. Autoradiographic analysis of 25 regions revealed effects of ACEA 1021 on CMRglu in the frontal, sensory, parietal and auditory cortices and the anteroventral and subthalamic nuclei. These changes deviated less than 15% from control. Effects on CBF were also small. The CMRglu and CBF effects of ACEA 1021 are substantially less than those previously observed for either competitive or non-competitive glutamate NMDA antagonists. We conclude that inhibition of the NMDA glycine recognition site has little or no effect on CMRglu or CBF at the doses examined. This is consistent with the absence of psychotomimetic effects observed for this class of drugs.


Assuntos
Encéfalo/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Glucose/metabolismo , Fármacos Neuroprotetores/farmacologia , Receptores de Glicina/antagonistas & inibidores , Animais , Encéfalo/metabolismo , Modelos Lineares , Masculino , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley
13.
J Neurosurg Anesthesiol ; 9(4): 316-23, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9339403

RESUMO

Fentanyl citrate has properties, including agonism of the mu-opioid receptor and proconvulsant activity, that theoretically could pose adverse effects in ischemic brain. This study examined the effects of high-dose fentanyl on outcome in rats subjected to transient near-complete forebrain ischemia. Rats were anesthetized with halothane and surgically prepared for ischemia. In one group (fentanyl; n = 15), intravenous fentanyl (400 micrograms/kg followed by an infusion of 16 micrograms/kg/min for 20 min) was administered and halothane was discontinued. In the remaining rats (control: n = 15), halothane administration was continued and no fentanyl was given. Following 10 min of bilateral carotid artery occlusion and profound systemic hypotension, animals were maintained normocapnic, normothermic, and mildly hyperoxemic for 8 h. Four days later, histologic and neurologic outcomes were assessed. In another group of rats also administered halothane (uncontrolled recovery; n = 15), no attempt was made to control physiologic variables during recovery from ischemia. Fentanyl caused preischemic evidence of epileptoid activity but decreased the percentage of neurons that died in the CA1 sector of the hippocampus relative to control (p = 0.0005). Damage in the cortex or caudoputamen was not different from that in the control group. Rats with an uncontrolled recovery had decreased damage in the cortex (p = 0.005) and caudoputamen (p = 0.00015) relative to control. In this model of forebrain ischemia, fentanyl caused no worsening of histologic damage in the cortex or caudoputamen and decreased hippocampal CA1 injury despite major electroencephalographic activation in the immediate preischemic period.


Assuntos
Anestésicos Intravenosos/farmacologia , Isquemia Encefálica/fisiopatologia , Fentanila/farmacologia , Prosencéfalo/irrigação sanguínea , Anestesia , Anestésicos Gerais/farmacologia , Anestésicos Intravenosos/administração & dosagem , Animais , Pressão Sanguínea/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Circulação Cerebrovascular/fisiologia , Eletroencefalografia/efeitos dos fármacos , Fentanila/administração & dosagem , Halotano/farmacologia , Masculino , Consumo de Oxigênio/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
14.
J Cereb Blood Flow Metab ; 17(7): 753-8, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9270492

RESUMO

Recent evidence suggests that apolipoprotein E (ApoE) plays a role in neurologic disease. This experiment compared the neurologic and histologic outcome of ApoE-deficient mutant and wild-type mice subjected to a 60- or 90-minute episode of middle cerebral artery filament occlusion and a recovery interval of 24 hours. With 60 minutes of ischemia, there was no mortality. Apolipoprotein E-deficient mice had larger infarcts (cortex: ApoE deficient = 20 mm3 +/- 12, wild-type = 9 +/- 7 mm3, P = 0.03; subcortex: ApoE deficient = 22 +/- 7 mm3, wild-type = 16 +/- 7 mm3, P = 0.07). Hemiparesis was less severe in wild-type animals (P = 0.02). After 90 minutes of ischemia, mortality in ApoE-deficient mice (n = 10) was 40% versus 0% in wild-type mice (n = 10; P = 0.09). Intraparenchymal hemorrhage was found in 3 of the 4 dead mice. No difference in cortical (ApoE deficient = 37 +/- 8 mm3; wild-type = 31 +/- 18 mm3; P = 0.49) or subcortical (ApoE deficient = 30 +/- 11 mm3; wild-type = 32 +/- 18 mm3; P = 0.78) infarct volumes was present among survivors. ApoE-deficient mice had a prolonged activated partial thromboplastin time and increased fibrinogen concentration. This data supports the hypothesis that apolipoprotein E plays a role in the pathophysiology of ischemic brain damage.


Assuntos
Apolipoproteínas E/deficiência , Isquemia Encefálica/etiologia , Animais , Tempo de Sangramento , Isquemia Encefálica/mortalidade , Isquemia Encefálica/fisiopatologia , Hemorragia Cerebral/etiologia , Hemorragia Cerebral/mortalidade , Infarto Cerebral/patologia , Suscetibilidade a Doenças , Masculino , Camundongos , Valores de Referência , Reperfusão , Análise de Sobrevida
16.
Neuroreport ; 8(5): 1139-42, 1997 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-9175101

RESUMO

This study examined the effect of glycine recognition site antagonism (ACEA 1021) on the incidence of spontaneous depolarizations in the penumbra of a focal ischemic lesion. Rats were administered either vehicle (n = 7), ACEA 1021 (n = 7) or dizocilpine (n = 5) and then underwent 90 min middle cerebral artery occlusion. The cortical direct current (DC) potential was recorded. During ischemia, 7 +/- 3 DC shifts occurred in the vehicle group. ACEA 1021 did not reduce this frequency (7 +/- 2 DC shifts) although dizocilpine did (1 +/- 1 DC shifts; p = 0.02). The previously demonstrated neuroprotective property of ACEA 1021 during focal cerebral ischemia cannot be attributed to reduction of spontaneous depolarization in the ischemic penumbra.


Assuntos
Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ataque Isquêmico Transitório/fisiopatologia , Fármacos Neuroprotetores/farmacologia , Quinoxalinas/farmacologia , Receptores de Glicina/antagonistas & inibidores , Animais , Masculino , Potenciais da Membrana/efeitos dos fármacos , Ratos , Ratos Wistar
17.
J Cereb Blood Flow Metab ; 17(2): 161-7, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9040495

RESUMO

Several lines of inquiry have indicated that glycine plays an important role in both glutamatergic neurotransmission and pathophysiology of cerebral ischemia. However, subacute outcome trials demonstrating the efficacy of glycine antagonists as neuroprotectants have not been performed with rigorous control of brain temperature. In this study, we investigated the effect of N-methyl-D-aspartate (NMDA) receptor glycine recognition site antagonism in a temperature-controlled rodent model of transient focal ischemia. Male Wistar rats underwent 75 min of intraluminal middle cerebral artery occlusion (MCAO). During MCAO and the first 24 h of reperfusion, rats (n = 10) were administered e55-nitro-6,7-dichloro-2,3-quinoxalinedione (ACEA 1021) i.v. as a bolus infusion of 5 mg/kg followed by 3.5 mg/kg/h (Low-Dose) or 10 mg/kg followed by 7 mg/kg/ h (High-Dose) for 24 h. Cortical temperature was controlled at 38.0 +/- 0.1 degrees C during MCAO and the first 6 h of reperfusion. A 7-day recovery interval was allowed. Mean total infarct volume was reduced by approximately 40% in both high- and low-dose groups (p < 0.01). The preponderance of infarct reduction occurred in the cortex (p < 0.01). Neurologic function correlated with the size of cerebral infarct (p = 0.001). Neurologic grade was similarly improved by treatment with either dose (p = 0.01). These results demonstrate that neuroprotection achieved by antagonism of the glycine recognition site persists when brain temperature is controlled, indicating a potent mechanism of action other than attenuating a hyperthermic response to ischemia.


Assuntos
Dano Encefálico Crônico/prevenção & controle , Isquemia Encefálica/tratamento farmacológico , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Glicina/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Quinoxalinas/uso terapêutico , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Sítios de Ligação , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Infarto Cerebral/patologia , Infarto Cerebral/prevenção & controle , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Antagonistas de Aminoácidos Excitatórios/farmacologia , Febre/prevenção & controle , Masculino , Fármacos Neuroprotetores/farmacologia , Quinoxalinas/administração & dosagem , Quinoxalinas/farmacologia , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/química , Receptores de N-Metil-D-Aspartato/metabolismo , Temperatura
18.
Clin Pediatr (Phila) ; 27(10): 479-83, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3048840

RESUMO

A series of seven children in Hawaii experienced transient cortical blindness following mild head trauma. All children, ages 3 through 8, recovered fully. The most prominent clinical feature was initial restlessness and agitation following relatively mild head trauma without significant loss of consciousness (LOC). One child may have experienced this several times. The clinical features associated with a benign outcome in this syndrome include: pediatric age group, mild head trauma, brief or no LOC, onset of blindness occurring within hours of the head injury, absent optokinetic nystagmus, duration of blindness less than 24 hours, agitation and restlessness, absence of skull fracture or visible cerebral injury on CT scan, absence of other neurological deficits, and EEG findings that initially show posterior slowing with subsequent normalization. Transiently fixed and dilated pupils have been described in these patients but should be viewed cautiously by clinicians in making this diagnosis, since cortical blindness is defined by sparing of the pupils. This syndrome may be underdiagnosed, since it may not be obvious that the child is blind unless the diagnosis is considered.


Assuntos
Cegueira/etiologia , Traumatismos Craniocerebrais/complicações , Cegueira/fisiopatologia , Criança , Pré-Escolar , Humanos , Masculino , Prognóstico
19.
JAMA ; 250(19): 2635-40, 1983 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-6313978

RESUMO

Simultaneous outbreaks of Guillain-Barré syndrome (GBS) and Bell's palsy occurred among residents of Hawaii during the three-month period June through August 1981. The outbreak of GBS (six cases) involved children, while the outbreak of Bell's palsy (22 cases) involved primarily adults. Four of the six patients with GBS had serological evidence of recent infection with cytomegalovirus (CMV) v none of 24 control subjects; no such association with CMV infection could be demonstrated for patients with Bell's palsy. The patients with GBS and Bell's palsy lived in widely scattered areas within the population centers of Hawaii, and no common exposures to specific places or events were identified. Testing for antibodies to respiratory pathogens suggested that a variety of antecedent viral infections, in addition to CMV infection, may have been associated with this unusual simultaneous cluster of illnesses.


Assuntos
Surtos de Doenças/epidemiologia , Paralisia Facial/epidemiologia , Polirradiculoneuropatia/epidemiologia , Adulto , Anticorpos Antivirais/análise , Criança , Pré-Escolar , Citomegalovirus/imunologia , Infecções por Citomegalovirus/epidemiologia , Paralisia Facial/microbiologia , Feminino , Havaí , Humanos , Masculino , Infecções Respiratórias/complicações , Risco , Estações do Ano , Fatores Socioeconômicos
20.
Am J Hum Genet ; 33(4): 513-8, 1981 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7258185

RESUMO

An isolated case of Duchenne muscular dystrophy in a female who has a de novo t(X;5)(p21;q35) translocation is described. The similarities between this patient and four previously reported females with Duchenne muscular dystrophy are discussed. It is concluded that the locus for Duchenne muscular dystrophy is at Xp21 and, furthermore, that this site may be particularly susceptible both to chromosome breakage and exchange and to gene mutation.


Assuntos
Mapeamento Cromossômico , Cromossomos Humanos 4-5 , Distrofias Musculares/genética , Cromossomos Sexuais , Translocação Genética , Cromossomo X , Criança , Bandeamento Cromossômico , Feminino , Humanos , Cariotipagem , Mutação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA