RESUMO
Among plants, pairs of selfing vs. outcrossing sister taxa provide interesting systems in which to test predictions concerning the magnitude and direction of temporal changes in sex allocation. Although resource availability typically declines towards the end of the growing season for annual taxa, temporal changes in mating opportunities depend on mating system and should change less in selfing taxa. Consequently, given that the pollen:ovule (P:O) ratio of flowers reflects the investment in (and potential fitness pay-off due to) male vs. female function, we predicted that the P:O ratio should also be less variable among and within selfers than in closely related outcrossers. To test these predictions, we measured temporal changes in sex allocation in multiple field populations of two pairs of sister taxa in the annual flowering plant genus Clarkia (Onagraceae). In the outcrossing Clarkia unguiculata and the selfing Clarkia exilis, ovule production declined similarly from early to late buds, whereas pollen production remained constant or increased in the outcrosser but remained constant or decreased in the selfer. Consequently, the P:O ratio increased within unguiculata populations but marginally increased or stayed constant in exilis populations. In all populations of the selfing Clarkia xantiana spp. parviflora and the outcrossing C. x. spp. xantiana, both ovule and pollen production per flower declined over time. The effects of these declines on the P:O ratio, however, differed between subspecies. In each xantiana population, the mean P:O ratio did not differ between early and late flowers, although individuals varied greatly in the direction and magnitude of phenotypic change. By contrast, parviflora populations differed in the mean direction of temporal change in the P:O ratio. We found little evidence to support our initial predictions that the P:O ratio of the selfing taxa will consistently vary less than in outcrossing taxa.
Assuntos
Clarkia/fisiologia , Flores/fisiologia , Endogamia , Clarkia/genética , Variação Genética , Reprodução/fisiologia , Fatores de TempoRESUMO
The purpose of this study is to test the sensitivity of the volumetric analysis compared to the visual analysis of the hippocampal formations of a group of 153 patients with clinical diagnosis of temporal lobe epilepsy and candidates to temporal lobectomy, evaluated by magnetic resonance (MR), using a 0.5 Tesla machine and inversion-recovery T1-weighted images and 5 mm coronal slices. There was agreement between the prospective visual analysis and another retrospective visual analysis carried out by two independent observers (C = 0.748 and C = 0.720). There was also agreement between the retrospective analysis of the two investigators (C = 0.733). There was genuine agreement (C = 0.788) between the results of the qualitative and quantitative analyses carried out prospectively. Volume measurements showed a nonsignificant tendency to lateralize more cases of clinically presumed hippocampal atrophy. Our results confirm the reliability of a qualitative visual analysis and indicate the utility of hippocampal volumetry as a supplementary, objective and quantitative measure of hippocampal sclerosis.
Assuntos
Epilepsia do Lobo Temporal/patologia , Hipocampo/patologia , Imageamento por Ressonância Magnética/métodos , Lobo Temporal/patologia , Adulto , Idoso , Atrofia , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , EscleroseRESUMO
We studied 5 patients with medically refractory temporal lobe epilepsy using special methods of MRI, in order to localize the epileptogenic area. Coronal sequences were obtained with 5 mm sections from the posterior margin of the brainstem to the base of the frontal lobe using: "Inversion recovery T1" (TR = 2500 msec, TE = 26 msec, T1 = 600 msec) to analyse loss of internal structure and atrophy of the hippocampus, and morphology of the temporal lobe; and Spin-echo T2w (TR = 250 msec, TE = 120 msec) looking for abnormal high intensity signal. In two cases with left focal EEG the MRI showed atrophy, loss of internal structure and abnormal high intensity signal in the hippocampus, and atrophy of the anterior temporal lobe, ipsilaterally. One case with independent bilateral foci at the EEG showed atrophy, loss of internal structure and abnormal high intensity signal in the right hippocampus. Other case with right focal EEG showed bilateral atrophy of the anterior temporal lobes. Another case was normal. We conclude that this methodology can facilitate the surgical indication in temporal lobe epilepsy.
Assuntos
Epilepsia do Lobo Temporal/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Eletroencefalografia , Epilepsia do Lobo Temporal/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Métodos especiais de MRI foram utilizados em 5 pacientes com epilepsia do lobo temporal refratários ao tratamento clínico, com a finalidade de localizar a área epileptogênica. Imagens coronais com espessura de 5mm foram obtidas da borda posterior do tronco cerebral até a base do lobo frontal, utilizando-se as sequências "Inversión Recovery T1" (TR=2500 msec, TE=26 msec, T1=600 msec) para avaliar perda de estrutura interna e atrofia do hipocampo e morfologia do lobo temporal; Spin-echo T2w (TR=2500 msec, TE=120 msec) visando a avaliar sinais de alta intensidade anormais. Em 2 casos com focos esquerdos no EEG, a MRI mostrou atrofia, perda de estrutura interna e aumento de sinal no hipocampo, e atrofia do lobo temporal anterior, ipsilateralmente. Um caso com focos bilaterais independentes no EEG teve atrofia, perda da estrutura interna e aumento de sinal no hipocampo direito. Um caso com EEG focal direito mostrou atrofia em ambos os lobos temporais anteriores. Outro caso näo mostrou anormalidades. Concluimos que esta metodologia pode facilitar a indicaçäo cirúrgica em epilepsia do lobo temporal
Assuntos
Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Epilepsia do Lobo Temporal/diagnóstico , Imageamento por Ressonância Magnética , Eletroencefalografia , Epilepsia do Lobo Frontal/terapiaRESUMO
Monotherapy is the policy for management of patients with epilepsy. With increasing knowledge of the biology of epilepsy and of the modes of action of antiepileptic drugs (AEDs), this concept must be reevaluated. When monotherapy fails to control seizures, subsequent treatment should be based on "rational pharmacology," taking into consideration the mode of action of the drugs, to provide improved efficacy with maintained tolerance and ease of administration. Introduction of vigabatrin (VGB) as a new AED calls for just such a reevaluation. VGB is an enzyme-activated irreversible inhibitor of gamma-aminobutyric acid (GABA)-transaminase that increases brain and cerebrospinal (CSF) GABA concentrations in animals and humans. It has limited efficacy in the classic animal seizure screening tests, but in many clinical studies has halved the incidence of seizures in approximately 50% of patients, especially those with partial epilepsies. We evaluated the efficacy of VGB in "socially integrated and active outpatients" as a likely subset to demonstrate any advantage of rational polytherapy. The criteria for this evaluation included the effects on seizure frequency, patient tolerability, and cognitive performance in a battery of psychometric tests. Fourteen of the 19 patients (73%) completing the study had > 50% reduction in seizure frequency, and 10 of 19 (52%) had > 70% reduction in seizure frequency. Tolerability appeared good; somnolence was the most frequent adverse event. Three patients complained of a worsening of their seizures, 1 with an increase in frequency and 2 with development of myoclonic jerks not previously reported.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Aminocaproatos/uso terapêutico , Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Adolescente , Adulto , Idoso , Assistência Ambulatorial , Aminocaproatos/efeitos adversos , Aminocaproatos/farmacologia , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/farmacologia , Cognição/efeitos dos fármacos , Quimioterapia Combinada , Epilepsia/diagnóstico , Epilepsia/psicologia , Feminino , Humanos , Masculino , Rememoração Mental/efeitos dos fármacos , Pessoa de Meia-Idade , Placebos , Testes Psicológicos , Índice de Gravidade de Doença , Método Simples-Cego , Sono/efeitos dos fármacos , Resultado do Tratamento , VigabatrinaRESUMO
The wide clinical spectrum of neurocysticercosis has led to many attempts at clinical, radiological, CSF and other classifications. Based on an objective review of the relevant literature and on a prospective study of 42 patients with active neurocysticercosis, a new classification is proposed, based on clinical, tomographic, magnetic resonance and CSF evidence of viability of cysts. The first step is to define whether the disease is active or not. Inactive disease may be parenchymal calcifications or hydrocephalus. Active disease may be intraparenchymal, extraparenchymal or mixed. Statistical analysis of 42 cases with active disease shows intraparenchymal disease to occur in younger patients, perhaps more frequently in females, and to have a better prognosis than extraparenchymal of mixed disease. The latter appears to have the worst prognosis. Therapeutic implications are that only active disease warrants etiological therapy. There remain doubts about the best therapy for some infrequent subtypes of extraparenchymal and mixed disease.
Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Cisticercose/diagnóstico , Adolescente , Adulto , Doenças do Sistema Nervoso Central/líquido cefalorraquidiano , Doenças do Sistema Nervoso Central/tratamento farmacológico , Doenças do Sistema Nervoso Central/etiologia , Criança , Pré-Escolar , Cisticercose/líquido cefalorraquidiano , Cisticercose/tratamento farmacológico , Cisticercose/etiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Praziquantel/uso terapêutico , Estudos Prospectivos , Tomografia Computadorizada por Raios XRESUMO
O amplo espectro clínico da neurocisticercose deu espaço a muitas tentativas de classificaçöes clínicas, radiológicas e de LCR, entre outras. Baseados em revisäo objetiva da literatura relevante e em estudo prospectivo de 42 casos de doença ativa, nova classificaçäo é proposta com base em evidências clínicas, tomográficas, de ressonância magnética ou LCR indicando viabilidade de cistos. O primeiro passo é establelecer se a doença é ou näo ativa. Doença ativa pode ser intra ou extraparenquimatosa, ou mista. Análise estatística de 42 casos com doença ativa demonstra que doença intraparenquimatosa ocorre em um grupo mais jovem, talvez mais no sexo feminino, e tem melhor prognóstico que doença extraparenquimatosa ou mista. Doença mista parece ter o pior prognóstico. Implicaçöes terapêuticas säo que somente doença ativa deve receber tratamento etiológico. Permanecem dúvidas sobre a melhor conduta em algumas formas infreqüentes de doença extraparenquimatosa ou mista
Assuntos
Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Cisticercose/líquido cefalorraquidiano , Doenças do Sistema Nervoso Central/líquido cefalorraquidiano , Doenças do Sistema Nervoso Central/diagnóstico , Doenças do Sistema Nervoso Central/etiologia , Cisticercose/diagnóstico , Cisticercose/tratamento farmacológico , Cisticercose/etiologia , Imageamento por Ressonância Magnética , Praziquantel/uso terapêutico , Estudos Prospectivos , Tomografia Computadorizada por Raios XRESUMO
Standard therapeutic regimens of praziquantel for neurocysticercosis use daily doses of 50 mg/kg for 15-21 days, with prolonged remission being achieved in 60-80% patients. In this prospective study, 100 mg/kg daily was used for 10 days in 13 patients aged 32 +/- 15 years (mean +/- SD) with severe intra-, extra-parenchymal or mixed forms of neurocysticercosis. Patients were monitored with computerized tomography and cerebrospinal fluid (CSF) examination on days 1, 5 and 10. Full blood count, sedimentation rate, blood sugar, urea, creatinine, bilirubin, liver transaminases, alkaline phosphatase, urine analysis and electrocardiogram were carried out before and after treatment. Doses of dexamethasone and of other drugs used concomitantly were controlled. There was no toxicity, clinical or detected by the methods employed in the study. After 22 +/- 5 (mean +/- SD) months follow-up, 6 patients needed ventriculoperitoneal shunting, 2 had died, 7 were improved and led useful lives and 4 were in prolonged remission. There was no correlation between serum or CSF praziquantel correlation and outcome of treatment. The proposed regimen is well tolerated, may be as efficient as previously advocated regimens, requires less hospitalization time and may be adopted routinely for therapy of neurocysticercosis.
Assuntos
Cisticercose/tratamento farmacológico , Doenças do Sistema Nervoso/tratamento farmacológico , Praziquantel/uso terapêutico , Adolescente , Adulto , Ventrículos Cerebrais/cirurgia , Derivações do Líquido Cefalorraquidiano , Criança , Pré-Escolar , Cisticercose/líquido cefalorraquidiano , Feminino , Humanos , Hidrocefalia/fisiopatologia , Lactente , Pressão Intracraniana , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/líquido cefalorraquidiano , Doenças do Sistema Nervoso/psicologia , Praziquantel/administração & dosagem , Praziquantel/efeitos adversos , RecidivaRESUMO
A 33-year-old female with neurofibromatosis and intracranial vascular lesions of the Moya-Moya type is reported. Clinical and angiographic aspects of both syndromes are discussed with respect to earlier reports of this rare association, with the conclusion that it produces slow intellectual and motor deterioration in adolescents or young adults. There are no specific guidelines to therapy, and the prognosis is mixed, some patients ceasing to progress at least for a few years.
Assuntos
Arteriopatias Oclusivas/complicações , Doença de Moyamoya/complicações , Neurofibromatose 1/complicações , Adulto , Angiografia Cerebral , Feminino , Humanos , Doença de Moyamoya/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
The risk/benefit ratio of acute anticoagulation in ischaemic cerebro-vascular disease is not clearly established. A simple and safe intermittent intravenous heparin regimen (20000 IU daily) was used prospectively in 50 patients of 57 +/- 14 (m +/- sd) years of age whose blood pressures ranged from normal to severe hypertension. Twenty-two patients had cardiogenic embolism and the remaining had recurrent severe transient ischaemic attacks of recent onset or progressive cerebral infarcts. Time of exposure to heparin was 6.4 +/- 4 (m +/- sd) days. Two patients had recurrences of cerebral thromboembolism and none had bleeding complications. This is a safe and efficient method of anticoagulation for patients with cerebral ischaemia when continuous infusion of heparin or close monitoring of clotting times are not used routinely.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Heparina/administração & dosagem , Doença Aguda , Adulto , Idoso , Esquema de Medicação , Feminino , Heparina/efeitos adversos , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Tempo de Tromboplastina Parcial , RiscoRESUMO
A relaçäo entre risco e benefício de anticoagulaçäo imediata em doença cerebrovascular isquêmica é discutível. Um regime simples e seguro de administraçäo endovenosa de heparina (20000 IU/dia) foi utilizado prospectivamente em 50 pacientes de 57 + ou - 14 (média + ou - desvio padräo) anos de idade cujas pressöes arteriais variaram de normais a hipertensäo severa. Vinte e dois dos pacientes sofreram embolia cerebral cardiogênica e o restante ataques isquêmicos transitórios de início recente ou infartos cerebrais progressivos. O tempo de exposiçäo à heparina foi de 6,4 + ou - 4 (média + ou - desvio padräo) dias. Dois pacientes tiveram recorrência de tromboembolismo cerebral e nenhum teve complicaçöes hemorrágicas. Este parece ser um método seguro e eficiente de anticoagulaçäo para pacientes com isquemia cerebral aguda, quando infusäo contínua de heparina ou monitorizaçäo de testes de coagulaçäo frequente näo säo usados rotineiramente