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1.
Clin Chem Lab Med ; 55(10): 1621-1629, 2017 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-28282291

RESUMO

BACKGROUND: Caspase-cleaved cytokeratin (CCCK)-18 is a protein released into the blood during apoptosis. Higher circulating CCCK-18 concentrations have been found in non-survivor than in survivor septic patients at moment of sepsis diagnosis. The following questions arise now: (1) How are serum CCCK-18 levels during the first week of sepsis? (2) Is there an association between sepsis severity and mortality and serum CCCK-18 levels during the first week? The aims of this study were to answer these questions. METHODS: Multicenter study with 321 severe septic patients from eight Spanish intensive care units. We determined serum concentration of CCCK-18, tumor necrosis factor (TNF)-α, and interleukin (IL)-10 during the first week. Our end-point study was 30-day mortality. RESULTS: Non-survivor (n=108) compared to survivor patients (n=213) showed higher serum CCCK-18 levels at days 1, 4 and 8 (p<0.001). ROC curve analyses showed that serum CCCK-18 levels at days 1 (AUC=0.77; 95% CI=0.72-0.82), 4 (AUC=0.81; 95% CI=0.76-0.85) and 8 (AUC=0.83; 95% CI=0.78-0.88) could predict mortality at 30 days (p<0.001). Logistic regression analyses showed that serum CCCK-18 levels at days 1 (OR=4.367; 95% CI=2.491-7.659), 4 (OR=10.137; 95% CI=4.741-21.678) and 8 (OR=8.781; 95% CI=3.626-21.268) were associated with 30-day mortality (p<0.001). We found a positive correlation between CCCK-18, SOFA, and lactic acid at days 1, 4 and 8. CONCLUSIONS: Non-survivor septic patients showed persistently during the first week higher serum CCCK-18 levels than survivor patients, and there is an association between sepsis severity and mortality and serum CCCK-18 levels during the first week.


Assuntos
Caspases/metabolismo , Queratina-18/sangue , Sepse/diagnóstico , Adulto , Idoso , Área Sob a Curva , Feminino , Humanos , Interleucina-10/sangue , Estimativa de Kaplan-Meier , Queratina-18/metabolismo , Ácido Láctico/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Sepse/mortalidade , Fatores de Tempo , Fator de Necrose Tumoral alfa/sangue
2.
Am J Infect Control ; 43(7): 711-4, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25934065

RESUMO

BACKGROUND: Cost-effectiveness analyses show that chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters reduce catheter-related bloodstream infection (CRBSI) and central venous catheter (CVC)-related costs. However, no studies have reported the efficiency of CHSS-impregnated catheters for venous access when the risk of CRBSI is low; for example, at the subclavian site. This study determined the cost of a CVC, diagnosis of CRBSI, and antimicrobial agents to treat CRBSI; we did not consider the cost of increased hospital stay. METHODS: This retrospective study included patients admitted to the intensive care unit at Hospital Universitario de Canarias (Tenerife, Spain) who had a subclavian venous catheter. RESULTS: Patients with CHSS catheters (n = 353) had a lower incidence density of CRBSI (2.12 vs 0 out of 1,000 catheter-days; P = .02) and lower CVC-related cost per catheter-day (3.35 ± 3.75 vs 3.94 ± 9.95; P = .002) than those with standard catheters (n = 518). CHSS-impregnated catheters were associated with a lower risk of CRBSI (exact logistic regression) (odds ratio, 0.10; 95% confidence interval, -∞ to 0.667; P = .008) than standard catheters when controlling for catheter duration. CHSS-impregnated catheters were also associated with a lower CVC-related cost per catheter day than standard catheters (Poisson regression) (odds ratio, 0.85; 95% confidence interval, 0.001-0.873; P < .001). CONCLUSIONS: CHSS-impregnated catheters may be efficient in preventing CRBSI in patients with subclavian venous access.


Assuntos
Infecções Relacionadas a Cateter/prevenção & controle , Cateterismo Venoso Central/métodos , Cateteres Venosos Centrais/microbiologia , Clorexidina/farmacologia , Desinfetantes/farmacologia , Desinfecção/métodos , Sulfadiazina de Prata/farmacologia , Adulto , Idoso , Infecções Relacionadas a Cateter/diagnóstico , Infecções Relacionadas a Cateter/economia , Cateteres Venosos Centrais/economia , Custos e Análise de Custo , Desinfecção/economia , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Espanha , Veia Subclávia
3.
Ann Neurol ; 77(5): 804-16, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25628166

RESUMO

OBJECTIVE: Lateral brain displacement has been associated with loss of consciousness and poor outcome in a range of acute neurologic disorders. We studied the association between lateral brain displacement and awakening from acute coma. METHODS: This prospective observational study included all new onset coma patients admitted to the Neurosciences Critical Care Unit (NCCU) over 12 consecutive months. Head computed tomography (CT) scans were analyzed independently at coma onset, after awakening, and at follow-up. Primary outcome measure was awakening, defined as the ability to follow commands before hospital discharge. Secondary outcome measures were discharge Glasgow Coma Scale (GCS), modified Rankin Scale, Glasgow Outcome Scale, and hospital and NCCU lengths of stay. RESULTS: Of the 85 patients studied, the mean age was 58 ± 16 years, 51% were female, and 78% had cerebrovascular etiology of coma. Fifty-one percent of patients had midline shift on head CT at coma onset and 43 (51%) patients awakened. In a multivariate analysis, independent predictors of awakening were younger age (odds ratio [OR] = 1.039, 95% confidence interval [CI] = 1.002-1.079, p = 0.040), higher GCS score at coma onset (OR = 1.455, 95% CI = 1.157-1.831, p = 0.001), nontraumatic coma etiology (OR = 4.464, 95% CI = 1.011-19.608, p = 0.048), lesser pineal shift on follow-up CT (OR = 1.316, 95% CI = 1.073-1.615, p = 0.009), and reduction or no increase in pineal shift on follow-up CT (OR = 11.628, 95% CI = 2.207-62.500, p = 0.004). INTERPRETATION: Reversal and/or limitation of lateral brain displacement are associated with acute awakening in comatose patients. These findings suggest objective parameters to guide prognosis and treatment in patients with acute onset of coma.


Assuntos
Encéfalo/diagnóstico por imagem , Coma/diagnóstico por imagem , Escala de Coma de Glasgow/tendências , Vigília , Doença Aguda , Adulto , Idoso , Encéfalo/fisiopatologia , Estudos de Coortes , Coma/fisiopatologia , Feminino , Seguimentos , Hospitalização/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Neuroimagem/tendências , Valor Preditivo dos Testes , Estudos Prospectivos , Tomografia Computadorizada por Raios X/tendências
4.
J Neurointerv Surg ; 6(5): e32, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24049112

RESUMO

We present a young woman with rapidly progressive neurologic decline in the setting of malignant cerebral edema due to extensive superior sagittal sinus thrombosis and cortical venous thrombosis despite intravenous heparin administration. Complete revascularization of the occluded sinus was achieved using suction thrombectomy with the 5 max Penumbra catheter in combination with the Solitaire FR clot retrieval device. The successful endovascular treatment halted the progression of her cerebral edema, and the patient eventually had an excellent recovery after prolonged intensive medical therapy. To our knowledge, this is the first reported case describing such a combined mechanical approach for cerebral venous sinus thrombosis. The clot retrieval properties of the Solitaire device combined with direct aspiration via the newest generation Penumbra catheters may allow more rapid, safe and efficient revascularization than all previously reported endovascular treatments for this potentially devastating condition.


Assuntos
Trombose dos Seios Intracranianos/cirurgia , Trombectomia/instrumentação , Trombectomia/métodos , Adulto , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/cirurgia , Revascularização Cerebral/instrumentação , Revascularização Cerebral/métodos , Cavidades Cranianas/diagnóstico por imagem , Cavidades Cranianas/cirurgia , Feminino , Humanos , Trombose dos Seios Intracranianos/diagnóstico por imagem , Sucção , Tomografia Computadorizada por Raios X , Resultado do Tratamento
5.
BMJ Case Rep ; 20132013 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-24022899

RESUMO

We present a young woman with rapidly progressive neurologic decline in the setting of malignant cerebral edema due to extensive superior sagittal sinus thrombosis and cortical venous thrombosis despite intravenous heparin administration. Complete revascularization of the occluded sinus was achieved using suction thrombectomy with the 5 max Penumbra catheter in combination with the Solitaire FR clot retrieval device. The successful endovascular treatment halted the progression of her cerebral edema, and the patient eventually had an excellent recovery after prolonged intensive medical therapy. To our knowledge, this is the first reported case describing such a combined mechanical approach for cerebral venous sinus thrombosis. The clot retrieval properties of the Solitaire device combined with direct aspiration via the newest generation Penumbra catheters may allow more rapid, safe and efficient revascularization than all previously reported endovascular treatments for this potentially devastating condition.


Assuntos
Trombose do Seio Sagital/cirurgia , Trombectomia/métodos , Adulto , Edema Encefálico/complicações , Feminino , Humanos , Trombose Intracraniana/complicações , Sucção/métodos , Resultado do Tratamento
6.
J Neurosurg ; 113(4): 774-80, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20367072

RESUMO

OBJECT: The purpose of this study was to identify predictors of shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH). METHODS: The authors evaluated the incidence of shunt-dependent hydrocephalus in a consecutive cohort of 580 patients with SAH who were admitted to the Neurological Intensive Care Unit of Columbia University Medical Center between July 1996 and September 2002. Patient demographics, 24-hour admission variables, initial CT scan characteristics, daily transcranial Doppler variables, and development of in-hospital complications were analyzed. Odds ratios and 95% CIs for candidate predictors were calculated using multivariate nominal logistic regression. RESULTS: Admission glucose of at least 126 mg/dl (adjusted OR 1.6; 95% CI 1.0-2.6), admission brain CT scan with a bicaudate index of at least 0.20 (adjusted OR 1.43; 95% CI 1.0-2.0), Fisher Grade 4 (adjusted OR 2.71; 95% CI 1.2-5.7), fourth ventricle hemorrhage (adjusted OR 1.78; 95% CI 1.1-2.7), and development of nosocomial meningitis (adjusted OR 2.2; 95% CI 1.4-3.7) were independently associated with shunt dependency. CONCLUSIONS: These data suggest that permanent CSF diversion after aneurysmal SAH may be independently predicted by hyperglycemia at admission, findings on the admission CT scan (Fisher Grade 4, fourth ventricle intraventricular hemorrhage, and bicaudate index ≥ 0.20), and development of nosocomial meningitis. Future research is needed to assess if tight glycemic control, reduction of fourth ventricle clot burden, and prevention of nosocomial meningitis may reduce the need for permanent CSF diversion after aneurysmal SAH.


Assuntos
Hidrocefalia/etiologia , Hidrocefalia/cirurgia , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/cirurgia , Derivação Ventriculoperitoneal , Adulto , Idoso , Estudos de Coortes , Determinação de Ponto Final , Feminino , Seguimentos , Escala de Coma de Glasgow , Humanos , Hidrocefalia/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Fatores de Risco , Hemorragia Subaracnóidea/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana
7.
Crit Care Med ; 37(6): 1893-7, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19384208

RESUMO

OBJECTIVE: To determine the impact of counter warming (CW) with an air circulating blanket on shivering and metabolic profile during therapeutic temperature modulation (TTM). DESIGN: A prospective observational study. SETTING: An 18-bed neurologic intensive care unit. PATIENTS: Fifty mechanically ventilated patients with brain injury undergoing TTM with automated surface and intravascular devices. INTERVENTIONS: Fifty indirect calorimetry (IDC) measurements with and without CW during TTM. MEASUREMENTS AND MAIN RESULTS: IDC was continuously performed for 10-15 minutes at baseline with CW (phase I), off CW (phase II), and again after the return of CW (phase III). Shivering severity during each phase was scored on a scale of 0-3 using the Bedside Shivering Assessment Scale (BSAS). Resting energy expenditure (REE), oxygen consumption, and carbon dioxide production were determined by IDC; 56% were women, with mean age 61 +/- 15 years. At the time of IDC, 72% of patients had signs of shivering (BSAS >0). All measures of basal metabolism increased after removal of the air warming blanket (from phases I and II); REE increased by 27% and oxygen consumption by 29% (both p < 0.002). A one-point increase in baseline BSAS was noted in 55% (n = 23/42) of patients from phase I to phase II. In a multivariate analysis, sedative use (p = 0.03), baseline moderate to severe shivering (p = 0.04), and lower serum magnesium levels (p = 0.01) were associated with greater increases in REE between phase I and phase II of CW. Phase III of CW was associated with a reversal in the increases in all metabolic variables. CONCLUSIONS: Surface CW provides beneficial control of shivering and improves the metabolic profile during TTM.


Assuntos
Metabolismo Energético , Calefação , Hipertermia Induzida/métodos , Hipotermia/metabolismo , Hipotermia/terapia , Estremecimento , Lesões Encefálicas/complicações , Lesões Encefálicas/metabolismo , Lesões Encefálicas/terapia , Calorimetria Indireta , Feminino , Humanos , Hipotermia/etiologia , Hipotermia Induzida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pele
8.
Stroke ; 39(12): 3242-7, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18927450

RESUMO

BACKGROUND AND PURPOSE: Therapeutic temperature modulation is widely used in neurocritical care but commonly causes shivering, which can hamper the cooling process and result in increases in systemic metabolism. We sought to validate a grading scale to assist in the monitoring and control of shivering. METHODS: A simple 4-point Bedside Shivering Assessment Scale was validated against continuous assessments of resting energy expenditure, oxygen consumption, and carbon dioxide production as measured by indirect calorimetry. Therapeutic temperature modulation for fever control or the induction of hypothermia was achieved with the use of a surface or endovascular device. Expected energy expenditure was calculated using the Harris-Benedict equation. A hypermetabolic index was calculated from the ratio of resting of energy expenditure to energy expenditure. RESULTS: Fifty consecutive cerebrovascular patients underwent indirect calorimetry between January 2006 and June 2007. Fifty-six percent were women, and mean age 63+/-16 years. The majority underwent fever control (n=40 [80%]) with a surface cooling device (n=44 [87%]) and had signs of shivering (Bedside Shivering Assessment Scale >0, 64% [n=34 of 50]). Low serum magnesium was independently associated with the presence of shivering (Bedside Shivering Assessment Scale >0; OR, 6.8; 95% CI, 1.7 to 28.0; P=0.01). The Bedside Shivering Assessment Scale was independently associated with the hypermetabolic index (W=16.3, P<0.001), oxygen consumption (W=26.3, P<0.001), resting energy expenditure (W=27.2, P<0.001), and carbon dioxide production (W=18.2, P<0.001) with a high level of interobserver reliability (kappa(w)=0.84, 95% CI, 0.81 to 0.86). CONCLUSIONS: The Bedside Shivering Assessment Scale is a simple and reliable tool for evaluating the metabolic stress of shivering.


Assuntos
Cuidados Críticos/métodos , Hipotermia Induzida , Índice de Gravidade de Doença , Estremecimento/fisiologia , Hemorragia Subaracnóidea/terapia , Idoso , Antropometria , Metabolismo Basal , Calorimetria Indireta , Dióxido de Carbono/metabolismo , Hemorragia Cerebral/metabolismo , Hemorragia Cerebral/fisiopatologia , Hemorragia Cerebral/terapia , Infarto Cerebral/metabolismo , Infarto Cerebral/fisiopatologia , Infarto Cerebral/terapia , Metabolismo Energético , Feminino , Humanos , Hipnóticos e Sedativos/farmacologia , Hipnóticos e Sedativos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Sistemas Automatizados de Assistência Junto ao Leito , Estudos Prospectivos , Estremecimento/efeitos dos fármacos , Hemorragia Subaracnóidea/metabolismo , Hemorragia Subaracnóidea/fisiopatologia
9.
Neuroimage ; 40(4): 1748-54, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18329289

RESUMO

Learning a complex motor skill is associated with changes in motor cortex representations of trained body parts. It has been suggested that representation changes reflect the storage of a skill, i.e., the motor memory trace. If a reflection of the trace, such modifications should persist after training is stopped for as long as the skill is retained. The objective here was to test the persistence of learning-related changes in the representation of the forelimb of the rat after learning a reaching task using repeated epidural stimulation mapping of primary motor cortex. It is shown that the forelimb representations enlarge after 8 days of training (n=8) but contract while performing arm movements without learning (n=7, p=0.006); hindlimb representations remain unchanged. Enlargement correlated with learning success (r=0.82; p=0.012). Subsequently, after 8 days without training, representation size reverted to baseline while the motor skill was retained. Somatotopy remained unaltered by a second training phase in which performance did not improve further (n=5). These findings suggest that successful acquisition but not storage of a motor skill depends on cortical map changes. The motor memory trace in rats may require changes in motor cortex organization other than those detected by stimulation mapping.


Assuntos
Córtex Cerebral/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Animais , Mapeamento Encefálico , Interpretação Estatística de Dados , Espaço Epidural/fisiologia , Membro Anterior/irrigação sanguínea , Membro Anterior/inervação , Modelos Lineares , Córtex Motor/fisiologia , Desempenho Psicomotor/fisiologia , Ratos , Ratos Long-Evans , Fluxo Sanguíneo Regional/fisiologia
10.
Exp Brain Res ; 181(2): 359-65, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17387461

RESUMO

Many motor rehabilitation therapies are based on principles of motor learning. Motor learning depends on preliminary knowledge of the trained and other (similar) skills. This study sought to investigate the influence of prior skill knowledge on re-learning of a precision reaching skill after a cortical lesion in rat. One group of animals recovered a previously known skill (skill training, followed by stroke and re-learning training, TST, n = 8). A second group learned the skill for the first time after stroke (ST, n = 6). A control group received prolonged training without stroke (n = 6). Unilateral partial motor cortex lesions were induced photothrombotically after identifying the forelimb representation using epidural stimulation mapping. In TST animals, re-learning after stroke was slower than learning before stroke (post hoc repeated measures ANOVA P = 0.039) and learning in the control group (P = 0.033). De novo learning after stroke (ST group) was not different from healthy learning. These findings show that skill learning can be performed if the motor cortex is partially lesioned; re-learning of a skill after stroke is slowed by prior knowledge of the skill. It remains to be tested in humans whether task novelty positively influences rehabilitation therapy.


Assuntos
Aprendizagem/fisiologia , Destreza Motora/fisiologia , Acidente Vascular Cerebral/psicologia , Animais , Peso Corporal/fisiologia , Interpretação Estatística de Dados , Força da Mão/fisiologia , Trombose Intracraniana/patologia , Trombose Intracraniana/psicologia , Modelos Lineares , Masculino , Córtex Motor/patologia , Desempenho Psicomotor/fisiologia , Ratos , Ratos Long-Evans , Acidente Vascular Cerebral/patologia
11.
J Neurosci Methods ; 161(1): 118-25, 2007 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-17178423

RESUMO

Stimulation mapping of motor cortex is an important tool for assessing motor cortex physiology. Existing techniques include intracortical microstimulation (ICMS) which has high spatial resolution but damages cortical integrity by needle penetrations, and transcranial stimulation which is non-invasive but lacks focality and spatial resolution. A minimally invasive epidural microstimulation (EMS) technique using chronically implanted polyimide-based thin-film microelectrode arrays (72 contacts) was tested in rat motor cortex and compared to ICMS within individual animals. Results demonstrate reliable mapping with high reproducibility and validity with respect to ICMS. No histological evidence of cortical damage and the absence of motor deficits as determined by performance of a motor skill reaching task, demonstrate the safety of the method. EMS is specifically suitable for experiments integrating electrophysiology with behavioral and molecular biology techniques.


Assuntos
Mapeamento Encefálico , Eletrodos Implantados , Microeletrodos , Córtex Motor/fisiologia , Análise de Variância , Animais , Comportamento Animal , Estimulação Elétrica/métodos , Eletrodos Implantados/efeitos adversos , Extremidades/inervação , Microeletrodos/efeitos adversos , Córtex Motor/efeitos da radiação , Ratos , Ratos Long-Evans , Reprodutibilidade dos Testes
12.
Curr Atheroscler Rep ; 8(4): 304-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16822396

RESUMO

Despite the highest mortality and morbidity of all forms of stroke, few advances have been made in the management of intracerebral hemorrhage (ICH). Besides specialized care in the stroke or neurologic intensive care unit, until very recently no specific therapies have been shown to improve outcome after ICH. Ventilatory support, blood pressure reduction, intracranial pressure monitoring, osmotherapy, fever control, seizure prophylaxis, and nutritional supplementation are the cornerstones of supportive care in the intensive care unit. Recently, a phase II trial of recombinant activated factor VII (NovoSeven; Novo Nordisk, Bagsvaerd, Denmark) reduced hematoma expansion, mortality, and disability when given within 3 hours of ICH onset. A phase III trial to confirm these results is now in progress.


Assuntos
Hemorragia Cerebral/tratamento farmacológico , Coagulantes/uso terapêutico , Hemostasia , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/fisiopatologia , Humanos , Prognóstico , Radiografia , Trombose Venosa/prevenção & controle
13.
Mol Neurobiol ; 32(3): 205-16, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16385137

RESUMO

Successful learning of a motor skill requires repetitive training. Once the skill is mastered, it can be remembered for a long period of time. The durable memory makes motor skill learning an interesting paradigm for the study of learning and memory mechanisms. To gain better understanding, one scientific approach is to dissect the process into stages and to study these as well as their interactions. This article covers the growing evidence that motor skill learning advances through stages, in which different storage mechanisms predominate. The acquisition phase is characterized by fast (within session) and slow learning (between sessions). For a short period following the initial training sessions, the skill is labile to interference by other skills and by protein synthesis inhibition, indicating that consolidation processes occur during rest periods between training sessions. During training as well as rest periods, activation in different brain regions changes dynamically. Evidence for stages in motor skill learning is provided by experiments using behavioral, electrophysiological, functional imaging, and cellular/molecular methods.


Assuntos
Encéfalo/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Neurônios/metabolismo , Animais , Encéfalo/citologia , Expressão Gênica , Humanos , Camundongos , Atividade Motora/fisiologia , Biossíntese de Proteínas
14.
Behav Brain Res ; 155(2): 249-56, 2004 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-15364484

RESUMO

Successful motor skill learning requires repetitive training interrupted by rest periods. In humans, improvement occurs within and between training sessions reflecting fast and slow components of motor learning [Karni A, Meyer G, Rey-Hipolito C, Jezzard P, Adams MM, Turner R, et al. The acquisition of skilled motor performance: fast and slow experience-driven changes in primary motor cortex. Proc Natl Acad Sci USA 1998;95:861-8]. Here, these components are characterized in male and female rats using a model of skilled forelimb reaching and are compared to time scales of instrumental learning. Twenty female and 14 male adult Long-Evans rats were pre-trained to operate a motorized door (via a sensor in the opposite cage wall) to access a food pellet by tongue. Latencies between pellet removal and door opening were recorded as measures of instrumental learning. After criterion performance was achieved, skilled forelimb reaching was requested by increasing the pellet-window distance to 1.5cm. Reaching success was recorded per trial. Mean latencies decreased exponentially over sessions and no improvement within-session was found. Skill learning over eight training sessions followed an exponential course in females and a sigmoid course in males. Females acquired the skill significantly faster than males starting at higher baseline levels (P < 0.001) but reaching similar plateaus. Within-session improvement was found during the sessions 1-3 in females and 1-4 in males. Performance at the end of session 1 was not carried over to session 2. Learning curves of individual animals were highly variable. These findings confirm in rat that motor skill learning has fast and slow components. No within-session improvement is seen in instrumental learning.


Assuntos
Condicionamento Operante/fisiologia , Membro Anterior/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Movimento/fisiologia , Tempo de Reação/fisiologia , Animais , Feminino , Masculino , Prática Psicológica , Ratos , Ratos Long-Evans , Fatores Sexuais , Fatores de Tempo
15.
Learn Mem ; 11(4): 379-82, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15286180

RESUMO

To investigate whether motor skill learning depends on de novo protein synthesis, adult rats were trained in an acrobatic locomotor task (accelerating rotarod) for 7 d. Animals were systemically injected with cycloheximide (CHX, 0.5 mg/kg, i.p.) 1 h before sessions 1 and 2 or sessions 2 and 3. Control rats received vehicle injections before sessions 1, 2, and 3. Although CHX did not affect improvement of performance within session 1, between-session improvement was impaired. In overtrained animals, comparable injections of CHX had no effect on rotarod performance. These findings suggest that consolidation of motor skills requires protein synthesis.


Assuntos
Condicionamento Operante/efeitos dos fármacos , Cicloeximida/farmacologia , Aprendizagem/efeitos dos fármacos , Destreza Motora/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Análise de Variância , Animais , Condicionamento Operante/fisiologia , Aprendizagem/fisiologia , Masculino , Memória/efeitos dos fármacos , Memória/fisiologia , Destreza Motora/fisiologia , Ratos , Ratos Long-Evans , Reforço Psicológico , Teste de Desempenho do Rota-Rod
16.
J Neurosci ; 24(29): 6515-20, 2004 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-15269262

RESUMO

The role of protein synthesis in memory consolidation is well established for hippocampus-dependent learning and synaptic plasticity. Whether protein synthesis is required for motor skill learning is unknown. We hypothesized that skill learning is interrupted by protein synthesis inhibition (PSI). We intended to test whether local protein synthesis in motor cortex or cerebellum is required during skill acquisition and consolidation. Anisomycin (ANI; 100 microg/microl in 1 microl of PBS) injected into motor cortex, posterior parietal cortex, or cerebellum produced 84.0 +/- 1.44% (mean +/- SEM), 85.9 +/- 2.31%, and 87.3 +/- 0.17% of PSI 60 min after administration, respectively. In motor cortex, protein synthesis was still reduced at 24 hr (72.0 +/- 4.68% PSI) but normalized at 48 hr after a second injection given 24 hr after the first. To test for the effects of PSI on learning of a skilled reaching task, ANI was injected into motor cortex contralateral to the trained limb or into ipsilateral cerebellum immediately after daily training sessions 1 and 2. Two control groups received motor cortex injections of vehicle or ANI injections into contralateral parietal cortex. Control and cerebellar animals showed a sigmoid learning curve, which plateaued after day 4. PSI in motor cortex significantly reduced learning during days 1-4. Thereafter, when protein synthesis normalized, learning was reinitiated. ANI injections into motor cortex did not induce a motor deficit, because animals injected during the performance plateau did not deteriorate. This demonstrates that motor skill learning depends on de novo synthesis of proteins in motor cortex after training.


Assuntos
Aprendizagem , Córtex Motor/metabolismo , Destreza Motora , Biossíntese de Proteínas , Animais , Anisomicina/farmacologia , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Masculino , Córtex Motor/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Ratos Long-Evans
17.
Exp Brain Res ; 158(3): 336-44, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15146305

RESUMO

Electrical stimulation (ES) is used after cardiac arrest (CA) for diagnostic and therapeutic purposes. The effects of ES on brain damage induced by hypoxic-ischemic brain injury (HI) has not been investigated. Stimulation of afferent pathways by ES may increase neural injury by releasing excitatory neurotransmitters (glutamate) and thereby exacerbating excitotoxicity. To test this hypothesis, ES was applied to the median nerve (2 h) of adult male Wistar rats after 5 min of asphyxic CA and cardiopulmonary resuscitation. Control animals received no ES. Assessment of neuronal damage in five regions of interest was performed in survivors (ESn=15, Control n=10, Sham n=3) after 48 h using H&E, Cresyl-Violet, and TUNEL stains, and Caspase-3 and activated ERK 1/2 immunohistochemistry. Ratios of injured to normal cells were calculated. Most injury was found in hippocampus and cerebellum. ES animals showed significantly lower injury ratios in bilateral hippocampus as compared with controls (F=20.8, p<0.00001). TUNEL staining, caspase-3 and activated ERK 1/2 showed no differences between groups. It is concluded that ES during the acute phase of HI does not amplify neuronal damage at 48 h, but may have a protective effect that requires further investigation.


Assuntos
Vias Aferentes/fisiopatologia , Infarto Cerebral/fisiopatologia , Terapia por Estimulação Elétrica , Hipóxia-Isquemia Encefálica/fisiopatologia , Degeneração Neural/fisiopatologia , Córtex Somatossensorial/fisiopatologia , Vias Aferentes/metabolismo , Animais , Caspase 3 , Caspases/metabolismo , Cerebelo/metabolismo , Cerebelo/patologia , Cerebelo/fisiopatologia , Infarto Cerebral/patologia , Infarto Cerebral/terapia , Modelos Animais de Doenças , Terapia por Estimulação Elétrica/efeitos adversos , Terapia por Estimulação Elétrica/métodos , Potenciais Somatossensoriais Evocados/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Lateralidade Funcional/fisiologia , Ácido Glutâmico/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Hipocampo/fisiopatologia , Hipóxia-Isquemia Encefálica/patologia , Hipóxia-Isquemia Encefálica/terapia , Masculino , Nervo Mediano/fisiologia , Degeneração Neural/patologia , Degeneração Neural/terapia , Ratos , Ratos Wistar , Córtex Somatossensorial/metabolismo , Córtex Somatossensorial/patologia
18.
Neurobiol Learn Mem ; 81(3): 211-6, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15082022

RESUMO

Rodent models of motor skill learning include skilled forelimb reaching and acrobatic locomotor paradigms. This study characterizes motor skill learning in the accelerated rotarod task. Thirty Long-Evans rats (300-400 g) were trained on an accelerated rotarod (1cm/s(2)) over eight consecutive sessions (=days, 20 trials each). Improvement in rotarod velocities mastered before falling off the rod was observed within and between sessions (plateau after five sessions). Intrasession improvement was incompletely retained at the beginning of the next day's session. Over several training sessions, intrasession improvement diminished, suggesting a ceiling effect. After 1 week of pause, the rotarod skill was retained. Locomotor exercise in a running wheel for 30 min before the first rotarod session did not affect intrasession improvement. Running-wheel exposure for 6 days did not diminish the rate of rotarod skill learning (steepness of the learning curve) but improved overall performance (upward shift of curve). Video analysis of gait on the rotarod showed that rats developed a motor strategy by modifying their gait patterns during training. The data demonstrate that rotarod improvement is not the result of enhanced general locomotor ability or fitness, which are trained in the running wheel, but requires a change in the motor strategy to master the task. Accelerated rotarod training can be regarded a valid paradigm for motor skill learning over short (intrasession, minutes) and long time frames (intersession, days).


Assuntos
Aprendizagem , Destreza Motora , Condicionamento Físico Animal , Prática Psicológica , Análise de Variância , Animais , Masculino , Ratos , Ratos Long-Evans , Teste de Desempenho do Rota-Rod
19.
Neurocrit Care ; 1(4): 455-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-16174949

RESUMO

INTRODUCTION: Increases in cerebral blood flow velocity (CBFV) as measured by transcranial Doppler (TCD) sonography are reflective of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). In serial TCD measurements, some patients exhibit CBFV temporal profiles with two peaks (biphasic). The significance of this finding remains unclear. This retrospective case-control study was conducted to investigate the characteristics and possible predictors of biphasic CBFV profiles. METHODS: Biphasic CBFV profiles were identified in serial TCD examinations (every 1-2 days) of 182 consecutive patients admitted for aneurysmal SAH based on CBFV profiles of the middle cerebral artery on the side of higher maximum velocity. Patients undergoing angioplasty were excluded. Patients meeting these criteria (study patients) were compared to control patients matched for age and Hunt and Hess grade. RESULTS: Eighteen patients (9.9%) demonstrated biphasic CBFV profiles. The first CBFV (134 +/- 11 cm/second) peak occurred on post-SAH day 6 +/- 1, and the second peak (148 +/- 12 cm/second) on day 13 +/- 1. Study patients more often exhibited focal (p < 0.05) symptoms at the time of the first peak. No patient deteriorated neurologically at the time of the second peak. No correlation was observed between CBVF and mean arterial pressure or central venous pressure trends. CONCLUSION: Serial TCD assessment identifies patients with SAH and a biphasic CBFV temporal profile. Although the second peak usually is not associated with a worsening of symptoms, these patients were more likely to exhibit clinical symptoms during the first CBFV peak.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/fisiopatologia , Aneurisma Intracraniano/complicações , Hemorragia Subaracnóidea/etiologia , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Circulação Cerebrovascular/fisiologia , Ecoencefalografia , Feminino , Hemodinâmica/fisiologia , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Hemorragia Subaracnóidea/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana
20.
Rev. venez. urol ; 49(1): 37-43, ene.-jun. 2003. tab, graf
Artigo em Espanhol | LILACS | ID: lil-412147

RESUMO

Evaluar si hay mejoría del grado de dolor provocado por la biopsia prostática (BP) guiada mediante ecosonogranma transrectal utilizando lidocaína instilada transrectal. Estudio prospectivo, randomizado (randomización 2 a 1), doble ciego y controlado, donde se instiló 40 cc de lidocaína viscosa al 2 por ciento o gel lubricante previo a la BP en pacientes con sospecha de cáncer por tacto rectal anormal o PSA por encima de 2,5 ng/ml. Se utilizó la escala visual análoga del dolor (EVAD) de 11 puntos y se interrogó al paciente si se sometería nuevamente al procedimiento sin anestesia o con ella. Ciento sesenta pacientes aptos para el análisis: ciento seis con lidocaína y 54 con gel. El promedio de biopsias realizadas por paciente fue de 13,61. Los grupos no diferían en cuanto a la edad, IPSS previo, volumen prostático, PSA ni número de biopsias realizadas. Los que recibieron lidocaína tuvieron valores promedio de EVAD de 4,44 ± 2,61 mientras que en los que recibieron placebo fue de 5,35 ± 2,54 (p<0,05). Los pacientes menores de 60 años presentaron más dolor; igual que los que tenían síntomas prostáticos moderados y severos. El aumento en el número de punciones no afectó adversamente el grado de dolor. El 79 por ciento de los pacientes (en ambos grupos) aceptaría repetirse la BP del mismo modo en que se le practicó, y un 11 por ciento adicional (también en ambos grupos) permitiría realizarla nuevamente con algún anestésico. La instatalción transrectal de lidocaína viscosa disminuye el dolor producido por la BP guiada por ecosonograma transrectal. Los pacientes menores de 60 años y aquellos con índices de IPSS de 8 o más son más propensos a tener valores de EVAD por la BP más elevados, sugiriendo que en estos pacientes se deben utilizar medidas adicionales (analgesia oral, parenteral o sedación)


Assuntos
Humanos , Masculino , Neoplasias da Próstata , Biópsia , Ultrassonografia , Anestesia Retal , Medição da Dor , Doenças Prostáticas , Urologia , Venezuela
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