RESUMO
MR diffusion/perfusion mismatch may help identify patients for acute stroke treatment, but mixed results from clinical trials suggest that further evaluation of the mismatch concept is required. To work effectively, mismatch should predict prognosis on arrival at hospital. We assessed mismatch duration and associations with functional outcome in acute stroke. We recruited consecutive patients with acute stroke, recorded baseline clinical variables, performed MR diffusion and perfusion imaging and assessed 3-month functional outcome. We assessed practicalities, agreement between mismatch on mean transit time (MTT) or cerebral blood flow (CBF) maps, visually and with lesion volume, and the relationship of each to functional outcome. Of 82 patients starting imaging, 14 (17%) failed perfusion imaging. Overall, 42% had mismatch (56% at <6 h; 41% at 12-24 h; 23% at 24-48 h). Agreement for mismatch by visual versus volume assessment was fair using MTT (kappa 0.59, 95% CI 0.34-0.84) but poor using CBF (kappa 0.24, 95% CI 0.01-0.48). Mismatch by either definition was not associated with functional outcome, even when the analysis was restricted to just those with mismatch. Visual estimation is a reasonable proxy for mismatch volume on MTT but not CBF. Perfusion is more difficult for acute stroke patients than diffusion imaging. Mismatch is present in many patients beyond 12 h after stroke. Mismatch alone does not distinguish patients with good and poor prognosis; both can do well or poorly. Other factors, e.g. reperfusion, may influence outcome more strongly, even in patients without mismatch.
Assuntos
Circulação Cerebrovascular/fisiologia , Imagem Ecoplanar/métodos , Acidente Vascular Cerebral/diagnóstico , Mapeamento Encefálico , Difusão , Imagem de Difusão por Ressonância Magnética , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Variações Dependentes do Observador , Avaliação de Resultados em Cuidados de Saúde , Perfusão , Valor Preditivo dos Testes , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Fatores de TempoAssuntos
Ataxia Cerebelar/diagnóstico por imagem , Ronco/diagnóstico por imagem , Gânglios da Base/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Atrofia de Múltiplos Sistemas/complicações , Atrofia de Múltiplos Sistemas/diagnóstico por imagem , Atrofias Olivopontocerebelares/complicações , Atrofias Olivopontocerebelares/diagnóstico por imagem , Radiografia , Sons RespiratóriosRESUMO
BACKGROUND: MR diffusion-weighted imaging (DWI) shows acute ischemic lesions early after stroke so it might improve outcome prediction and reduce sample sizes in stroke treatment trials. Previous studies of DWI and outcome produced conflicting results. OBJECTIVE: To determine whether DWI lesion characteristics independently predict outcome in a broad range of patients with acute stroke. METHODS: The authors recruited hospital-admitted patients with all severities of suspected stroke, assessed stroke severity on the NIH Stroke Scale (NIHSS), performed early brain DWI, and assessed outcome at 3 months (modified Rankin Scale). Clinical data and DWI lesion parameters were evaluated in a logistic regression model to identify independent predictors of outcome at 3 months and a previously described "Three-Item Scale" (including DWI) was tested for outcome prediction. RESULTS: Among 82 patients (mean NIHSS 7.1 [+/-6.3 SD]), the only independent outcome predictors were age and stroke severity. Neither DWI lesion volume nor apparent diffusion coefficient nor the previously described Three-Item Scale predicted outcome independently. Comparison with previous studies suggested that DWI may predict outcome only in patients with more severe cortical ischemic strokes. CONCLUSIONS: Across a broad range of stroke severities, diffusion-weighted imaging (DWI) did not predict outcome beyond that of key clinical variables. Thus, DWI is unlikely to reduce sample sizes in acute stroke trials assessing functional outcome, especially where estimated treatment effects are modest.
Assuntos
Isquemia Encefálica/diagnóstico , Imagem de Difusão por Ressonância Magnética , Acidente Vascular Cerebral/diagnóstico , Doença Aguda , Idoso , Isquemia Encefálica/epidemiologia , Isquemia Encefálica/patologia , Testes Diagnósticos de Rotina/estatística & dados numéricos , Imagem de Difusão por Ressonância Magnética/estatística & dados numéricos , Feminino , Humanos , Modelos Logísticos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/patologia , Resultado do TratamentoRESUMO
BACKGROUND AND PURPOSE: An acute mismatch on diffusion-weighted MRI (DWI) and perfusion-weighted MRI (PWI) may represent the "tissue-at-risk." It is unclear which "semiquantitative" perfusion parameter most closely identifies final infarct volume. METHODS: Acute stroke patients underwent DWI and PWI (dynamic-susceptibility contrast imaging) on admission (baseline), and T2-weighted imaging (T2WI) at 1 or 3 months after stroke. "Semiquantitative" mean transit time (MTTsq=first moment of concentration/time curve), cerebral blood volume (CBVsq=area under concentration/time curve), and cerebral blood flow (CBFsq=CBVsq/MTTsq) were calculated. DWI and PWI lesions were measured at baseline and final infarct volume on T2WI acquired > or =1 month after stroke. Baseline DWI, CBFsq, and MTTsq lesion volumes were compared with final T2WI lesion volume. RESULTS: Among 46 patients, baseline DWI and CBFsq lesions were not significantly different from final T2WI lesion volume, but baseline MTTsq lesions were significantly larger. The correlation with final T2WI lesion volume was strongest for DWI (Spearman rank correlation coefficient rho=0.68), intermediate for CBFsq (rho=0.55), and weakest for MTTsq (rho=0.49) baseline lesion volumes. Neither DWI/CBFsq nor DWI/MTTsq mismatch predicted lesion growth; lesion growth was equally common in those with and without mismatch. CONCLUSIONS: Of the 2 PWI parameters, CBFsq lesions most closely identifies, and MTTsq overestimates, final T2WI lesion volume. "DWI/PWI mismatch" does not identify lesion growth. Patients without "DWI/PWI mismatch" are equally likely to have lesion growth as those with mismatch and should not be excluded from acute stroke treatment.
Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Isquemia/patologia , Imageamento por Ressonância Magnética/métodos , Acidente Vascular Cerebral/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular , Difusão , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Isquemia/diagnóstico , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Perfusão , Estudos Prospectivos , Acidente Vascular Cerebral/diagnóstico , Fatores de TempoRESUMO
OBJECTIVES: To assess organisational and patient specific limitations and safety of magnetic resonance imaging (MRI) as the first line investigation for hospital admitted stroke patients. METHODS: Consecutive patients admitted with acute stroke were assessed and an attempt was made to perform MRI in all patients. Oxygen saturation and interventions required during scanning were recorded. RESULTS: Among 136 patients recruited over 34 weeks, 85 (62%) underwent MRI. The patients' medical instability (15 of the 53 not scanned), contraindications to MRI (six of the 53 not scanned), and rapid symptom resolution (10 of the 53 not scanned) were the main reasons for not performing MRI. Of the 85 patients who underwent MRI, 26 required physical intervention, 17 did not complete scanning, and 11 of the 61 who had successful oxygen saturation monitoring were hypoxic during MRI. Organisational limitations accounted for only 13% of failures to scan. CONCLUSIONS: Up to 85% of hospital admitted acute stroke patients could have MRI as first line imaging investigation, but medical instability is the major limitation. Hypoxia is frequent in MRI. Patients should be monitored carefully, possibly by an experienced clinician, during scanning.
Assuntos
Imageamento por Ressonância Magnética/efeitos adversos , Seleção de Pacientes , Acidente Vascular Cerebral/patologia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Contraindicações , Estudos de Viabilidade , Feminino , Hospitalização , Humanos , Hipóxia/etiologia , Hipóxia/prevenção & controle , Masculino , Pessoa de Meia-Idade , Oxigênio/metabolismo , Reabilitação do Acidente Vascular CerebralRESUMO
OBJECTIVES: Our purpose was to investigate whether differences exist in the values and temporal evolution of mean diffusivity (
Assuntos
Isquemia Encefálica/patologia , Encéfalo/patologia , Acidente Vascular Cerebral/patologia , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Isquemia Encefálica/complicações , Imagem de Difusão por Ressonância Magnética , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações , Fatores de TempoRESUMO
OBJECTIVE: To assess the educational outcome and utilization of special education resources at age 8 years in children who were born extremely prematurely, and to compare this outcome with a matched cohort of children born full-term. METHODS: All children with gestational age less than 28 weeks or birthweight of less than 1000 g, born at Royal North Shore Hospital from July 1985 through June 1990 were enrolled in a study of long-term outcome. A cohort of full-term children matched for age, sex and school with non-disabled extremely premature children was enrolled at age 8 years. Children were assessed using standardized measures of cognitive and academic achievement. Information was obtained from teachers regarding educational support and academic progress. RESULTS: Of 82 extremely premature children assessed at age 8 years, 8 (10%) had a severe disability, 13 (16%) had a mild or moderate disability and 61 (74%) were non-disabled (IQ > or = 85, no neurosensory disability). Thirty-five (43%) required special education support, 22 (27%) were below grade level in reading or mathematics and 25 (30%) were performing at grade level without support. Compared with controls, non-disabled extremely premature children had lower scores on standardized measures of academic achievement and were more likely to be reported by teachers as falling below grade level in reading (48% vs 13%; P < 0.001), mathematics (48% vs 10%; P < 0.001) and spelling (48% vs 17%; P < 0.002), and to require special education support (25% vs 4%; P = 0.004). CONCLUSION: Parents and professionals caring for extremely premature children need to be alert to the additional support that these children may require at school.
Assuntos
Cegueira/classificação , Paralisia Cerebral/classificação , Crianças com Deficiência/classificação , Escolaridade , Recém-Nascido Prematuro , Análise de Variância , Cegueira/complicações , Estudos de Casos e Controles , Paralisia Cerebral/complicações , Criança , Estudos de Coortes , Dislexia/diagnóstico , Dislexia/etiologia , Educação Inclusiva , Humanos , Recém-Nascido , Testes de InteligênciaRESUMO
This study explored the prevalence and stability of behaviour problems and their prediction from neonatal, medical and family context factors in a group of extremely low birthweight (ELBW) infants assessed at 5 and 8 years of age. Behaviour problems were identified on the basis of several measures: the Total Behaviour Problem Scale and the Adaptive Function Scale of the Child Behaviour Checklist, and the Hyperactivity Index and Hyperactivity Scale from the Conners' Rating Scale. In this group of ELBW infants, the prevalence of behaviour difficulties was somewhat lower than that reported in other studies, and varied according to the measure and informant (parent vs. teacher) used. Also, there was little continuity between those children identified by their parents at 5 years of age as having behaviour problems and those children identified by parent and/or teacher report at 8 years of age. Most of the children identified with behaviour difficulties at 8 years were also reported to have academic difficulties. None of the neonatal or medical factors predicted behaviour difficulties at 8 years of age. In contrast, two family context factors, maternal level of education and family stress, were related to behaviour difficulties at 8 years. These findings indicate that ELBW and the often associated medical complications may not necessarily predispose infants to develop subsequent behaviour difficulties later on in childhood.
Assuntos
Transtornos do Comportamento Infantil/epidemiologia , Recém-Nascido de Baixo Peso , Adulto , Criança , Pré-Escolar , Escolaridade , Feminino , Humanos , Recém-Nascido , Masculino , Mães , New South Wales/epidemiologia , Prevalência , Estudos ProspectivosAssuntos
Ataxia/fisiopatologia , Mutação de Sentido Incorreto , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Canais de Potássio/genética , Adulto , Idade de Início , Ataxia/genética , Austrália , Criança , Disartria/fisiopatologia , Família , Feminino , Marcha Atáxica/fisiopatologia , Movimentos da Cabeça , Humanos , Canal de Potássio Kv1.1 , Masculino , Mioquimia/fisiopatologia , Linhagem , Tremor/fisiopatologia , Gravação de VideoteipeRESUMO
BACKGROUND AND PURPOSE: Because of its precise connectivity and functional specificity, the rat whisker-barrel system offers an excellent opportunity to study experience-dependent neuroplasticity. However, data are lacking regarding the neuroplasticity of this system after cerebral ischemia. The purpose of the present study was to develop a reproducible model for the production of ischemia/reperfusion of the posteromedial barrel subfield (PMBSF) in the rat, which is the visible representation of the large whiskers on the opposite face. METHODS: Focal cortical ischemia was induced in male Sprague-Dawley rats (n=40) by slowly compressing the intact dura (maximum 0.05 mm/s) with a 4- or 5-mm-diameter brass cylinder equipped with a laser-Doppler probe, combined with ipsilateral common carotid artery occlusion. The microvascular blood flow of PMBSF during compression ischemia was maintained at 18% to 20% of baseline flow for 1 hour. The total infarction volume was measured by 2,3,5-triphenyltetrazolium chloride staining at several reperfusion times, and pathological examination was performed on hematoxylin-eosin-stained sections. RESULTS: The infarct volumes were 36.5+/-9.2 (n=9), 40.7+/-7.7 (n=7), and 36.6+/-6.4 mm(3) (n=5) at 24 hours, 72 hours, and 7 days after ischemia, respectively, with no significant differences among these values. There was no evidence of damage to white matter or to deep gray matter and no evidence of hemorrhage. The topographic distribution of the damaged tissue was in good agreement with that of PMBSF. CONCLUSIONS: This stroke model produces a highly consistent cortical infarct in PMBSF and can facilitate the study of behavioral, functional, and structural consequences after cerebral ischemia/reperfusion in the rat somatosensory cortex.
Assuntos
Isquemia Encefálica/patologia , Modelos Animais de Doenças , Ratos , Córtex Somatossensorial/irrigação sanguínea , Animais , Infarto Encefálico/patologia , Isquemia Encefálica/etiologia , Isquemia Encefálica/fisiopatologia , Circulação Cerebrovascular , Corantes/química , Masculino , Plasticidade Neuronal , Pressão , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Sais de Tetrazólio/química , VibrissasRESUMO
OBJECTIVES: To determine the safety and efficacy of intravenous lignocaine infusion in patients with severe chronic daily headache (CDH). DESIGN: Retrospective survey of consecutive patients. PARTICIPANTS: 19 patients, 18 with rebound headache and three with status migrainosus. Two patients had both conditions at different times. SETTING: Neurology unit in a major metropolitan teaching hospital, 1994-1998. MAIN OUTCOME MEASURES: Adverse events; headache resolution; long term efficacy. RESULTS: The 19 patients (16 women) received 27 lignocaine infusions. Seven minor adverse events were noted during four infusions. Twenty-two infusions were given for analgesic rebound headache in 18 patients, with headache resolution in 82% of infusions (17 of the 18 patients responded at least once). Four patients obtained lasting relief, six returned to their regular manageable pattern of migraine (in two of these patients CDH recurred after six months), four were lost to follow-up, and in four there was no long term benefit. Five infusions were given for status migrainosus in three patients, with four of these infusions successfully relieving the headache. CONCLUSIONS: Intravenous lignocaine appears to be useful in the management of severe intractable CDH and status migrainosus.
Assuntos
Anestésicos Locais/uso terapêutico , Lidocaína/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Cefaleia do Tipo Tensional/tratamento farmacológico , Adolescente , Adulto , Doença Crônica , Protocolos Clínicos , Monitoramento de Medicamentos/métodos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Nitric oxide (NO) has been proposed as an intercellular messenger mediating postsynaptic to presynaptic information transfer in the induction of long-term potentiation. A number of studies support the possible involvement of NO in synaptic plasticity. NO may have a role in synaptogenesis and synaptic plasticity in developing rat brain and may play a fundamental part in the process of regeneration, plasticity, and retargeting of axons following injury. We examined the possible role of NO on plasticity in the rat first somatosensory cortex with [14C]2-deoxyglucose (2-DG) autoradiography in rats treated daily with l-nitroarginine (l-NA) following neonatal unilateral vibrissae deafferentation. After 6 weeks of l-NA treatment, the local cerebral glucose utilization (LCGU) and the spatial extent of the metabolic activation following stimulation of the spared whisker was measured. NOS catalytic activity exhibited significant inhibition throughout the treatment period. Vibrissae deafferentation produced a small but not statistically significant increase of LCGU in the vibrissa activated C3 barrel, and l-NA treatment did not alter the activation of LCGU in the deafferented cortex following whisker stimulation. Additionally, l-NA treatment did not alter the area of metabolic activation on either the non-deafferented side or the deafferented side. Deafferentation produced a 298% increase in the metabolic representation of the spared C3 barrel following stimulation in the saline treated animals, a 257% increase in the chronically l-NA treated animals, and a 256% increase in the short-term treated animals, all with respect to the response in the non-deafferented cortex. Metabolic plasticity in the barrel cortex was not attenuated by l-NA treatment. These results show that nitric oxide does not play a major role on developmental cortical plasticity induced by vibrissae deafferentation in the rat.
Assuntos
Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico/fisiologia , Nitroarginina/farmacologia , Córtex Somatossensorial/efeitos dos fármacos , Vias Aferentes/efeitos dos fármacos , Animais , Autorradiografia , Catálise , Plasticidade Neuronal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial/enzimologia , Vibrissas/inervaçãoRESUMO
The single-vibrissa stimulation model in the rat was utilized to study the microvascular coupling between functional activation and local cerebral blood flow (LCBF) in both normal cortex and in cortex that had been peripherally deafferented. In addition, the role of chronic nitric oxide synthase (NOS) inhibition on the LCBF response to vibrissa stimulation was examined. One-day-old rats underwent deafferentation of all vibrissae on one side of the face, sparing C3, and received daily administration of either saline or N omega-nitro-L-arginine (L-NA). After seven weeks of treatment, LCBF was measured autoradiographically in conscious rats with [14C]N-isopropyl-p-iodoamphetamine while C3 was stimulated bilaterally. Stimulation produced a greater increase in LCBF in the deafferented cortex of both the saline (30.4%) and L-NA treated (25.7%) animals than in the intact cortex (19.9% and 16%, respectively). The area of activation of LCBF (0.176 mm2) was comparable to the area metabolically activated (0.149 mm2), and the increase in area of LCBF activation following deafferentation (169%) was smaller than the increase in area that was metabolically activated (287%). Chronic inhibition of NOS did not alter the spatial extent of the blood-flow response.
Assuntos
Circulação Cerebrovascular/fisiologia , Óxido Nítrico/metabolismo , Córtex Somatossensorial/irrigação sanguínea , Córtex Somatossensorial/enzimologia , Animais , Animais Recém-Nascidos , Autorradiografia , Radioisótopos de Carbono , Denervação , Desoxiglucose , Glucose/metabolismo , Plasticidade Neuronal/fisiologia , Óxido Nítrico Sintase/metabolismo , Estimulação Física , Ratos , Ratos Sprague-Dawley , Vibrissas/inervaçãoRESUMO
In unanaesthetized rats, mechanical stimulation of a single vibrissa increased glucose utilization in one cortical column of the somatosensory area and in several spots in the dorsolateral neostriatum, predominantly on the side contralateral to the stimulation. Two or three peaks of glucose utilization unique to the stimulated animals were seen in cross sections throughout a 1.8 mm anteroposterior extent in the dorsolateral striatum. These observations suggest that one cortical column is functionally related to several neostriatal regions. The distributed modularity may be an important characteristic of the basal ganglia system.
Assuntos
Metabolismo Energético/fisiologia , Neostriado/metabolismo , Córtex Somatossensorial/fisiologia , Vibrissas/fisiologia , Animais , Autorradiografia , Ratos , Ratos Sprague-DawleyRESUMO
In this work, we developed and implemented a multimodality multidimensional imaging system which is capable of generating and displaying anatomical and functional images of selected structures and processes within a vertebrate's central nervous system (CNS). The functional images are generated from [14C]-2-deoxy-D-glucose (2DG) autoradiography whereas the anatomic images are derived from cytochrome oxidase (CO) histochemistry. This multi-modality imaging system has been used to study mechanisms underlying information processing in the rat brain. We have applied this technique to visualize and measure the plasticity (deformation) observed in the rat's whisker system due to neonatal lesioning of selected peripheral sensory organs. Application of this imaging system revealed detailed information about the shape, size, and directionality of selected cortical and subcortical structures. Previous 2-D imaging techniques were unable to deliver such holistic information. Another important issue addressed in this work is related to image registration problems. We developed an image registration technique which employs extrinsic fiduciary marks for alignment and is capable of registering images with subpixel accuracy. It uses the information from all available fiduciary marks to promote alignment of the sections and to avoid propagation of errors across a serial data set.
Assuntos
Encéfalo/diagnóstico por imagem , Animais , Autorradiografia , Desoxiglucose , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Processamento de Imagem Assistida por Computador , Plasticidade Neuronal , Ratos , Tomografia Computadorizada de Emissão , VibrissasRESUMO
Three-dimensional (3-D) reconstruction of autoradiograms can provide new insights into the functional relationship of neural regions. To reach full potential, however, 3-D reconstruction must be both accurate and efficient. In this paper, we present a novel image matching algorithm that simultaneously aligns a set of serial sections and uses the method to reconstruct whisker barrels from the rat cerebral cortex. We initially compared several alignment techniques and found that our Multi-Set Registration (MSR) algorithm produced superior accuracy. This algorithm is based on a least-squares minimization technique and is able to simultaneously register a set of serial sections with subpixel precision (30-micron accuracy). We applied our new technique to the 3-D reconstruction of a series of autoradiograms. Our objective was to visualize and measure the 3-D metabolic (functional) shape of normal (control) and developmentally altered (plastic) C3 vibrissa columns in the first somatosensory area of the rat cerebral cortex. The plastic C3 metabolic column showed a nearly 450% increase in volume when compared to the control column. In addition, the lesion-altered C3 column-in contrast to the normal C3 column-displayed no central zone of high activity, and patches of higher metabolic activity were scattered throughout the columnar profile. This metabolic activity was not confined to the cylindrical column, but extended tangentially as radiating fingerlike projections toward neighboring barrels.
Assuntos
Autorradiografia , Glicemia/metabolismo , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Processamento de Imagem Assistida por Computador , Algoritmos , Animais , Animais Recém-Nascidos , Autorradiografia/instrumentação , Córtex Cerebral/anatomia & histologia , Sistemas Computacionais , Fluordesoxiglucose F18/metabolismo , Processamento de Imagem Assistida por Computador/instrumentação , Plasticidade Neuronal/fisiologia , Ratos , Córtex Somatossensorial/anatomia & histologia , Córtex Somatossensorial/fisiologia , Vibrissas/inervaçãoRESUMO
Autoradiography has been used to visualize independently the subtypes of beta-adrenergic receptors in rat somatosensory cortex. Beta 2-Adrenergic receptors, but not beta 1-adrenergic receptors colocalize with "whisker barrels" in this tissue. Thus, each whisker sends a specific multisynaptic pathway to the somatosensory cortex that can be histochemically visualized and only one subtype of beta-adrenergic receptor is specifically associated with this cortical representation. Additionally, neonatal lesion of any or all of the whisker follicles results in loss of the corresponding barrel(s) as shown by histochemical markers. This loss is paralleled by a similar loss in the organization of beta 2-adrenergic receptors in the somatosensory cortex. Other results indicate that these beta 2-adrenergic receptors are not involved in moment-to-moment signal transmission in this pathway and, additionally, are not involved in a gross way in the development of whisker-barrel array.
Assuntos
Receptores Adrenérgicos beta/fisiologia , Córtex Somatossensorial/fisiologia , Vibrissas/fisiologia , Vias Aferentes/fisiologia , Animais , Animais Recém-Nascidos , Autorradiografia , Clembuterol/farmacologia , Desoxiglucose/metabolismo , Regulação para Baixo/efeitos dos fármacos , Histocitoquímica , Radioisótopos do Iodo , Estimulação Física , Pindolol/análogos & derivados , Pindolol/metabolismo , Propranolol/farmacologia , Ratos , Ratos Endogâmicos , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores Adrenérgicos beta/metabolismo , Valores de Referência , Succinato Desidrogenase/metabolismo , Sinapses/fisiologia , Vibrissas/inervaçãoRESUMO
Feline leukemia virus status and antibody titer to feline oncornavirus-associated cell membrane antigen (FOCMA) were determined on plasma from 183 outpatient cats and 61 cats from 2 closed, FeLV-positive, multiple-cat households. Cats with FOCMA antibody titer had a significantly (P less than 0.02) higher prevalence of history of disease than did cats without FOCMA antibody. Diseases included upper respiratory tract infections, abscesses, ear infections, lower urinary tract infections, gastrointestinal disease, pneumonia, uterine infection, lymphadenopathy, fever of unknown origin, and bacterial infections. The FOCMA antibody titer was determined by use of an indirect fluorescent antibody test; titer greater than or equal to 1:16 was considered to be positive results. Lower mean FOCMA antibody titer was observed in young cats with history of disease (P less than 0.05) than in young cats without history of disease or in older cats with or without history of disease. Prevalence of FOCMA antibody titer was identical (38%) in young and adult cats, indicating cats likely were exposed to FeLV as kittens because a higher prevalence of FOCMA antibody titer in older cats would otherwise be expected.