Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Pharmacol Biochem Behav ; 100(3): 545-53, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22037411

RESUMO

NMDAR-mediated excitotoxicity has been implicated in some of the impairments following fetal ethanol exposure. Previous studies suggest that both neuronal cell death and some of the behavioral deficits can be reduced by NMDAR antagonism during withdrawal, including antagonism of a subpopulation of receptors containing NR2B subunits. To further investigate NR2B involvement, we selected a compound, CP-101,606 (CP) which binds selectively to NR2B/2B stoichiometries, for both in vitro and in vivo analyses. For the in vitro study, hippocampal explants were exposed to ethanol for 10 days and then 24 h following removal of ethanol, cellular damage was quantified via propidium iodide fluorescence. In vitro ethanol withdrawal-associated neurotoxicity was prevented by CP (10 and 25 nM). In vivo ethanol exposure was administered on PNDs 1-7 with CP administered 21 h following cessation. Activity (PNDs 20-21), motor skills (PNDs 31-33), and maze navigation (PNDs 43-44) were all susceptible to ethanol insult; treatment with CP (15 mg/kg) rescued these deficits. Our findings show that CP-101,606, a drug that blocks the NR2B/2B receptor, can reduce some of the damaging effects of "3rd trimester" alcohol exposure in our rodent model. Further work is clearly warranted on the neuroprotective potential of this drug in the developing brain.


Assuntos
Neuropatia Alcoólica/prevenção & controle , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Transtornos do Espectro Alcoólico Fetal/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Piperidinas/uso terapêutico , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Animais Recém-Nascidos , Ansiedade/etiologia , Ansiedade/prevenção & controle , Comportamento Animal/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Transtornos do Espectro Alcoólico Fetal/patologia , Transtornos do Espectro Alcoólico Fetal/fisiopatologia , Hipocampo/patologia , Deficiências da Aprendizagem/etiologia , Deficiências da Aprendizagem/prevenção & controle , Masculino , Transtornos das Habilidades Motoras/etiologia , Transtornos das Habilidades Motoras/prevenção & controle , Neurônios/efeitos dos fármacos , Neurônios/patologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
2.
Neuroscience ; 206: 245-54, 2012 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-22119644

RESUMO

Current therapies for attention deficit hyperactivity disorder (ADHD) have varying efficacy in individuals with fetal alcohol spectrum disorders (FASD), suggesting that alternative therapeutics are needed. Developmental exposure to ethanol produces changes in dopamine (DA) systems, and DA has also been implicated in ADHD pathology. In the current study, lobeline, which interacts with proteins in dopaminergic presynaptic terminals, was evaluated for its ability to attenuate neonatal ethanol-induced locomotor hyperactivity and alterations in dopamine transporter (DAT) function in striatum and prefrontal cortex (PFC). From postnatal days (PND) 1-7, male and female rat pups were intubated twice daily with either 3 g/kg ethanol or milk, or were not intubated (non-intubated control) as a model for "third trimester" ethanol exposure. On PND 21 and 22, pups received acute lobeline (0, 0.3, 1, or 3 mg/kg), and locomotor activity was assessed. On PND 23-25, pups again received an acute injection of lobeline (1 or 3 mg/kg), and DAT kinetic parameters (Km and V(max)) were determined. Results demonstrated that neonatal ethanol produced locomotor hyperactivity on PND 21 that was reversed by lobeline (1 and 3 mg/kg). Although striatal DAT function was not altered by neonatal ethanol or acute lobeline, neonatal ethanol exposure increased the V(max) for DAT in the PFC, suggesting an increase in DAT function in PFC. Lobeline ameliorated this effect on PFC V(max) at the same doses that decreased hyperactivity. Methylphenidate, the gold standard therapeutic for ADHD, was also evaluated for comparison with lobeline. Methylphenidate decreased DAT V(max) and Km in PFC from ethanol-treated pups. Thus, lobeline and methylphenidate differentially altered DAT function following neonatal ethanol exposure. Collectively, these findings provide support that lobeline may be a useful pharmacotherapy for some of the deficits associated with neonatal ethanol exposure.


Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Etanol/toxicidade , Estimulantes Ganglionares/farmacologia , Lobelina/farmacologia , Córtex Pré-Frontal/metabolismo , Animais , Animais Recém-Nascidos , Feminino , Masculino , Córtex Pré-Frontal/efeitos dos fármacos , Agitação Psicomotora/etiologia , Agitação Psicomotora/prevenção & controle , Ratos , Ratos Sprague-Dawley
3.
Anaesth Intensive Care ; 32(1): 11-21, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15058115

RESUMO

This review looks at the evidence for the effectiveness of spinal cord stimulation in various chronic pain states. Spinal cord stimulation can only be effective when appropriate dorsal column fibres in the spinal cord are preserved and able to be stimulated. Spinal cord stimulation has been shown to have little to offer for patients with some diagnoses. Although 50 to 60% of patients with failed back surgery syndrome obtain significant pain relief with this technique, the strength of the evidence available is insufficient to clearly advocate its use in all patients with this condition. Though limited in quantity and quality, better evidence exists for its use in neuropathic pain, complex regional pain syndrome, angina pectoris and critical limb ischaemia. There is a lack of high quality evidence relating to spinal cord stimulation due to difficulties in conducting randomized controlled trials in this area. Serious methodological problems are encountered in blinding, recruitment and assessment in nearly all published trials of spinal cord stimulation. Suggestions regarding appropriate methodologies for trials which would produce better quality evidence are summarized.


Assuntos
Terapia por Estimulação Elétrica , Manejo da Dor , Medula Espinal/fisiologia , Doença Crônica , Humanos , Dor Lombar/cirurgia , Dor Lombar/terapia , Avaliação de Resultados em Cuidados de Saúde , Dor/cirurgia , Doenças Vasculares Periféricas/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Percept Mot Skills ; 92(3 Pt 1): 643-52, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11453187

RESUMO

Some sports photographs are remarkable for how animate they appear, whereas others seem particularly static or frozen. To explore the aspects of still photographs that might produce a sense of action, 34 observers viewed all possible pairs of 14 previously published images depicting sports figures in action and were asked to judge their similarity under two conditions, image-focus (how similar are the images) or movement-focus (how similar is the type of movement). A separate group of observers also rated each image on eight scales. Multidimensional scaling analyses suggested that in the image-focus condition, subjects tended to organize their judgments around three general dimensions, e.g., on-ground versus off-ground, while in the movement-focus condition the subjects were more likely to cluster the images along the lines of the particular activity, throwing, running, or jumping. We discuss the problem of movement depiction in sports photographs and make suggestions for research on the effects of facial expressions, muscular strain, and amount of limb extension.


Assuntos
Percepção , Fotografação/normas , Esportes , Adolescente , Adulto , Feminino , Humanos , Masculino
5.
Development ; 126(9): 1927-35, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10101126

RESUMO

Formation of brain requires deftly balancing primary genesis of neurons and glia, detection of when sufficient cells of each type have been produced, shutdown of proliferation and removal of excess cells. The region and cell type-specific expression of cell cycle regulatory proteins, such as demonstrated for cyclin D2, may contribute to these processes. If so, regional brain development should be affected by alteration of cyclin expression. To test this hypothesis, the representation of specific cell types was examined in the cerebellum of animals lacking cyclin D2. The loss of this cyclin primarily affected two neuronal populations: granule cell number was reduced and stellate interneurons were nearly absent. Differences between null and wild-type siblings were obvious by the second postnatal week. Decreases in granule cell number arose from both reduction in primary neurogenesis and increase in apoptosis of cells that fail to differentiate. The dearth of stellate cells in the molecular layer indicates that emergence of this subpopulation requires cyclin D2 expression. Surprisingly, Golgi and basket interneurons, thought to originate from the same precursor pool as stellate cells, appear unaffected. These results suggest that cyclin D2 is required in cerebellum not only for proliferation of the granule cell precursors but also for proper differentiation of granule and stellate interneurons.


Assuntos
Cerebelo/embriologia , Cerebelo/crescimento & desenvolvimento , Ciclinas/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas do Tecido Nervoso/fisiologia , Neurônios/fisiologia , Envelhecimento , Animais , Apoptose , Ciclo Celular , Diferenciação Celular , Divisão Celular , Cerebelo/patologia , Cruzamentos Genéticos , Ciclina D2 , Ciclinas/deficiência , Ciclinas/genética , Desenvolvimento Embrionário e Fetal , Heterozigoto , Interneurônios/citologia , Interneurônios/patologia , Interneurônios/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Neurônios/citologia , Neurônios/patologia
6.
J Neurosci ; 16(1): 210-9, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8613787

RESUMO

Although the regulation of proliferation and differentiation during brain development has long been considered to be interrelated, the mechanisms that coordinate the control of cell division and histogenesis are poorly understood. The cell cycle is a dynamic process that is governed by the concerted action of numerous cell cycle regulatory proteins in response to signals both intrinsic and extrinsic to the cell. Thus, proteins that regulate the cell cycle are well suited to provide a link between processes that control neuroblast proliferation and differentiation. We reported previously the isolation from brain of a message form of D2 cyclin, one of several cyclin proteins known to promote the progression from G1 to S phase. This MN20/D2 cyclin mRNA is expressed in highly restricted neural populations at embryonic (E) day 15 and postnatal (P) day 6 in the mouse. To gain insight into the role(s) this cyclin may serve in brain formation, the spatial and temporal pattern of MN20/D2 cyclin expression was examined by in situ hybridization at 48 hr intervals from E10.5 to P8. MN20 mRNA was detected in developing cerebellum, dorsal mesencephalon, cerebral cortex, and epithalamus, but not hippocampus, striatum, or thalamus. Comparison with 5-bromodeoxyuridine labeling of cells in S phase indicated that MN20 expression in embryonic cerebellum and cerebral cortex was most pronounced in young neurons that recently had become postmitotic. Although expressed in other embryonic cerebellar neurons, MN20 was detected in granule precursors only postnatally, after their migration from the rhombic lip to the external germinal layer. This indicates that MN20/D2 cyclin is induced in cerebellar granule precursors as they become competent to differentiate. The spatial distribution of MN20 expression in the developing brain suggests that regional differences in cell cycle regulation depend in part on the selective use of cyclin proteins. Moreover, detection of MN20 mRNA in postmitotic neural cells indicates that cyclin D2 expression has effects beyond promoting cell cycle progression and may also have a role in the response of the neural precursor to terminal differentiation signals as the cells exits from proliferation.


Assuntos
Ciclinas/genética , Camundongos Endogâmicos C57BL/embriologia , Proteínas do Tecido Nervoso/genética , Neurônios/fisiologia , Animais , Encéfalo/embriologia , Encéfalo/fisiologia , Ciclina D2 , Embrião de Mamíferos/citologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Hibridização In Situ , Masculino , Camundongos , Mitose/fisiologia , RNA Mensageiro/análise , Fatores de Tempo
7.
Brain Res ; 647(1): 153-60, 1994 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-8069699

RESUMO

In this study, we address the hypothesis that enhancement of gamma-aminobutyric acid (GABA) neurotransmission following an ischemic episode is neuroprotective in the hippocampus. Mongolian gerbils were subjected to transient forebrain ischemia for 5 min by occlusion of the carotid arteries and then administered diazepam (10 mg/kg i.p.) 30 min or 30 and 90 min following ischemia. Diazepam produced a significant decrease in both rectal and brain temperature (4-6 degrees C) in the sham and ischemic gerbils. 1 day following the onset of reperfusion, diazepam substantially reduced the hyperactivity normally induced by the ischemic episode. 7 days later, neuronal viability in the hippocampus was assessed. The single dose of diazepam completely protected the CA1 pyramidal cells of the hippocampus in 62% of the gerbils and the double dose of diazepam completely protected CA1 pyramidal neurons in 67% of the gerbils. There was a significant correlation between the degree of pyramidal cell degeneration in the CA1 area of the hippocampus measured 7 days following ischemia and the degree of hyperactivity measured 1 day following ischemia. Diazepam also prevented the loss of [35S]t-butylbicyclophosphorothionate ([35S]TBPS) binding to GABA-gated chloride channels in the dendritic fields of the CA1 area of the hippocampus. Our findings support the hypothesis that enhancement of GABA neurotransmission following an ischemic event may offset neuronal excitability and prevent neuronal death in specific brain regions. We conclude that GABA-enhancing drugs, such as diazepam, are attractive candidates as neuroprotective agents following ischemic insults.


Assuntos
Isquemia Encefálica/fisiopatologia , Compostos Bicíclicos Heterocíclicos com Pontes , Diazepam/farmacologia , Hipocampo/efeitos dos fármacos , Animais , Temperatura Corporal , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Compostos Bicíclicos com Pontes/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Gerbillinae , Hipocampo/patologia , Hipocampo/fisiopatologia , Masculino , Atividade Motora/efeitos dos fármacos , Reto
8.
Bone Marrow Transplant ; 10(6): 535-40, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1362687

RESUMO

A programme of repeated high dose chemotherapy for advanced breast cancer was developed using (1) cyclophosphamide 4 g/m2 followed by autologous peripheral blood stem cell (PBSC) collection; (2) three cycles of conventional dose chemotherapy; (3) high dose cyclophosphamide, cisplatin, and carmustine with PBSC rescue; and (4) high dose etoposide and melphalan with PBSC rescue. Fifteen eligible patients had advanced poor prognosis breast cancer either at initial diagnosis (one patient) or at relapse (14 patients). During the course of the protocol, there were three treatment related deaths, two patient withdrawals due to debilitating toxicity, five patient withdrawals due to disease progression, and one patient withdrawal due to inadequate collection of PBSC. The remaining four patients did not complete the planned protocol as the programme was terminated because of the unacceptable morbidity and mortality. They were treated with an alternative high dose chemotherapy protocol which was well tolerated. This study highlights the significant problems associated with a complex sequential high dose chemotherapy regimen. Cyclophosphamide mobilized PBSC infused following high dose chemotherapy enables rapid haematological recovery. However the non-haematological toxicity following high dose chemotherapy regimens is often severe and may limit the application of certain sequential high dose chemotherapy combinations in patients with breast cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transplante de Medula Óssea , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Transfusão de Sangue , Terapia Combinada , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Pessoa de Meia-Idade , Transplante Autólogo
11.
Australas Radiol ; 35(3): 237-41, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1763986

RESUMO

A prospective study was undertaken to assess the usefulness, safety and cost-effectiveness of stereotactically guided carbon localisation of impalpable breast lesions. Fifty six lesions in 53 patients were localised by this method, some in combination with fine-needle aspiration and hookwire localisation. Some modification of the study was required due to ready acceptance of the technique by surgeons, who preferred carbon to hookwire localisation. The technique was proven to be safe and accurate, and highly acceptable to patients, referring clinicians and radiology staff. It is now the preferred procedure for localising impalpable breast lesions prior to excision biopsy.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Carbono , Mamografia/métodos , Técnicas Estereotáxicas , Biópsia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/cirurgia , Feminino , Humanos , Palpação , Estudos Prospectivos
15.
J Nerv Ment Dis ; 174(6): 336-41, 1986 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3711876

RESUMO

In order to evaluate thought disorder in a nonschizophrenic psychotic group, psychotic depressives were compared with chronic paranoid schizophrenics and normal control subjects on two assessments of thought pathology. The data indicate that: a) psychotic depressives show thought deficits in the same areas as chronic paranoid schizophrenics, and b) idiosyncratic thinking is the single most prominent thought disorder in both psychotic groups. Certain subtypes of thought disorder may be characteristic of psychosis in general rather than of any specific diagnostic category. A psychoticism profile would include idiosyncratic thinking, restricted abstracting ability, linguistic errors, content deficit, intermixing, and loss of goal.


Assuntos
Transtorno Depressivo/psicologia , Testes Psicológicos , Esquizofrenia Paranoide/psicologia , Adulto , Doença Crônica , Transtornos Cognitivos , Transtorno Depressivo/diagnóstico , Diagnóstico Diferencial , Feminino , Hospitalização , Humanos , Masculino , Psicometria , Esquizofrenia Paranoide/diagnóstico , Pensamento
18.
Br Med J (Clin Res Ed) ; 287(6387): 247-8, 1983 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-6409267

RESUMO

Four cases of severe bradycardia developed during surgery in patients given the neuromuscular blocking agent atracurium as part of the anaesthesia. In all cases sinus rhythm was restored by giving intravenous atropine. It is recommended that in all operations in which vagal stimulation is expected patients should be given atropine as part of the premedication or induction sequence and should undergo full electrocardiographic monitoring during surgery.


Assuntos
Anestesia Geral/efeitos adversos , Bradicardia/induzido quimicamente , Isoquinolinas/efeitos adversos , Bloqueadores Neuromusculares/efeitos adversos , Adulto , Idoso , Atracúrio , Atropina/uso terapêutico , Feminino , Humanos , Complicações Intraoperatórias/tratamento farmacológico , Pessoa de Meia-Idade
19.
Theriogenology ; 16(4): 399-405, 1981 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16725652

RESUMO

The effects of repeated laparoscopic surgery on the length of the bovine estrous cycle, estrus, ovulation and corpus luteum function were determined after one estrous cycle of normal duration (18 to 24 days). Five, Angus x Hereford cows were subjected to laparoscopy on days 5, 13, 18 and 20 (estrus = day 0) of the subsequent cycle. Blood was collected daily during the cycle in which laparoscopy was performed (surgical cycle) and during the next cycle (postsurgical cycle). Lengths of the surgical and postsurgical cycles (22.3 +/- .5 days and 21.5 +/- .6 days, respectively) did not differ (P>.05) from that of the presurgical cycle (21.8 +/- .2 days). Average concentrations (ng/ml) of LH and progesterone in serum were similar during the surgical and postsurgical cycles (1.2 +/- .1, 2.2 +/- .2 vs 1.3 +/- .2 and 2.3 +/- .1). Progesterone concentrations remained above 1 ng/ml for 17 and 16 days during the surgical and postsurgical cycles, respectively. A pre-ovulatory rise in LH, along with estrus and ovulation was confirmed in all animals. Follicular development, characterized by follicular volume, increased progressively from days 5 to 20, with the largest increase occurring between days 13 and 18. These results indicate that laparoscopy, used at the times and frequency specified, does not alter reproductive function of cyclic cows and can provide information on ovarian activity.

20.
Biochim Biophys Acta ; 633(2): 154-61, 1980 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-7193053

RESUMO

Intact, but sham-operated female rats had 2- to 3-fold higher levels of hepatic 3-hydroxy-3-methylglutaryl CoA reductase activity than their male counterparts (15--21.5 vs. 6.7--8.7 nmol mevalonate/mg protein per h). The activity of the hepatic enzyme declined to about the same relative degree (40--60%) in male and female rats that were gonadectomized after puberty (53 days of age) and killed 5 weeks later. Implantation of silastic capsules containing 17 beta-estradiol increased the level of hepatic 3-hydroxy-3-methylglutaryl CoA reductase to levels found in sham-operated controls. In rats that were gonadectomized in infancy (12 h old) and killed 7--8 weeks later, the level of enzyme activity was not altered in females, but it was increased from 60--240% in males. Consequently, following neonatal gonadectomy, male-female differences in enzyme activity were no longer apparent. Implantation of silastic capsules containing estradiol in neonatally gonadectomized rats resulted in a doubling of enzyme activity in both males and females. Ovariectomy reduced plasma estrogen levels, but implantation of estradiol in gonadectomized males and females increased the hormone level to that found in sham-operated females. Thus, the results strongly suggest a role for physiologic levels of estrogen as a positive effector of 3-hydroxy-3-methylglutaryl CoA reductase activity. Neonatal sex imprinting also appears to modulate the enzyme activity since sex-mediated differences are effaced by gonadectomy in infancy, but not by gonadectomy following puberty.


Assuntos
Estrogênios/sangue , Hidroximetilglutaril-CoA Redutases/metabolismo , Microssomos Hepáticos/enzimologia , Maturidade Sexual , Animais , Animais Recém-Nascidos , Peso Corporal , Castração , Estradiol/farmacologia , Estro , Feminino , Fixação Psicológica Instintiva , Masculino , Gravidez , Ratos , Fatores Sexuais , Testosterona/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...