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OBJECTIVE: Prenatally detected central nervous system (CNS) anomalies present a diagnostic challenge. In this study, we compared the diagnostic yield of exome sequencing (ES) and chromosomal microarray analysis (CMA) in fetuses with a major CNS anomaly. METHODS: This was a retrospective study of 114 cases referred for genetic evaluation following termination of pregnancy (TOP) due to a major CNS anomaly detected on prenatal ultrasound. All fetuses were first analyzed by CMA. All CMA-negative cases were offered ES. CMA-positive cases were reanalyzed using ES to assess its ability to detect copy-number variants (CNVs). RESULTS: CMA identified a pathogenic or likely pathogenic (P/LP) CNV in 11/114 (10%) cases. Eighty-six CMA-negative cases were analyzed using ES, which detected P/LP sequence variants in 38/86 (44%). Among recurrent cases (i.e. cases with a previously affected pregnancy), the incidence of P/LP sequence variants was non-significantly higher compared with non-recurrent ones (12/19 (63%) vs 26/67 (39%); P = 0.06). Among the 38 cases with an ES diagnosis, 20 (53%) were inherited and carried a significant risk of recurrence. Reanalysis of 10 CMA-positive cases by ES demonstrated that the bioinformatics pipeline used for sequence variant analysis also detected all P/LP CNVs, as well as three previously known non-causative CNVs. CONCLUSIONS: In our study, ES provided a high diagnostic yield (> 50%) in fetuses with severe CNS structural anomalies, which may have been partly due to the highly selected case series that included post-TOP cases from a specialist referral center. These data suggest that ES may be considered as a first-tier test for the prenatal diagnosis of major fetal CNS anomalies, detecting both P/LP sequence variants and CNVs. This is of particular importance given the time constraints of an ongoing pregnancy and the risk of recurrence in future pregnancies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
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Enfermedades del Sistema Nervioso Central , Malformaciones del Sistema Nervioso , Sistema Nervioso Central/diagnóstico por imagen , Enfermedades del Sistema Nervioso Central/diagnóstico , Enfermedades del Sistema Nervioso Central/genética , Aberraciones Cromosómicas , Variaciones en el Número de Copia de ADN/genética , Exoma , Femenino , Feto/anomalías , Humanos , Análisis por Micromatrices , Malformaciones del Sistema Nervioso/diagnóstico por imagen , Malformaciones del Sistema Nervioso/genética , Embarazo , Diagnóstico Prenatal , Estudios Retrospectivos , Secuenciación del ExomaRESUMEN
STUDY QUESTION: What is the optimal timing for blastomere biopsy during the 8-cell stage, at which embryos will have the best implantation potential? SUMMARY ANSWER: Fast-cleaving embryos that are biopsied during the last quarter (Q4) of the 8-cell stage and are less affected by the biopsy procedure, and their implantation potential is better than that of embryos biopsied earlier during the 8-cell stage (Q1-Q3). WHAT IS KNOWN ALREADY: Blastomer biopsy from cleavage-stage embryos is usually performed on the morning of Day 3 when the embryos are at the 6- to 8-cell stage and is still the preferred biopsy method for preimplantation genetic diagnosis (PGD) for monogentic disorders or chromosomal translocations. Human embryos usually remain at the 8-cell stage for a relatively long 'arrest phase' in which cells grow, duplicate their DNA and synthesize various proteins in preparation for the subsequent division. STUDY DESIGN, SIZE, DURATION: This is a retrospective cohort study. The study group (195 embryos) included all 8-cell stage embryos that underwent blastomere biopsy for PGD for monogenetic disorders and chromosomal translocations in our unit between 2012-2014 and cultured in the EmbryoScope until transfer. The control group (115 embryos) included all embryos that underwent intracytoplasmic sperm injection without a biopsy during the same period. PARTICIPANTS/MATERIALS, SETTING, METHODS: The 8-cell stage was divided into four quarters: the first 5 h post-t8 (Q1), 5-10 h post-t8 (Q2), 10-15 h post-t8 (Q3) and at 15-20 h post-t8 (Q4). Non-biopsied control embryos were divided into four equivalent quarters. Embryos were evaluated for timing of developmental events following biopsy including timing of first cleavge after biopsy, timing of comapction (tM) and start of blastulation (tSB). Timing of these events were compared between PGD and control embryos, as well as with 56 PGD implanted embryos with Known Implantation Data (PGD-KID-positive embryos). MAIN RESULTS AND THE ROLE OF CHANCE: Embryos that were biopsied during Q3 (10-15 h from entry into 8-cell stage) were delayed in all three subsequent developmental events, including first cleavage after biopsy, compaction and start of blastulation. In contrast, these events occurred exactly at the same time as in the control group, in embryos that were biopsied during Q1, Q2 or Q4 of the 8-cell stage. The results show also that embryos that were biopsied during Q1, Q2 or Q3 of the 8-cell stage demonstrated a significant delay from the biopsied implanted embryos already in t8 as well as in tM and tSB. However, embryos that were biopsied during Q4 demonstrated dynamics similar to those of the biopsied implanted embryos in t8 and tM, and a delay was noticed only in the last stage of tSB. LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study that is limited to the timing of biopsy that is routinely performed in the IVF lab. A prospective study in which biopsy will be performed at a desired timing is needed in order to differ between the effect of biopsy itself and the cleavage rate of the embryo. WIDER IMPLICATIONS OF THE FINDINGS: Our findings showed that blastomere biopsy can be less harmful to further development if it is carried out during a critical period of embryonic growth, i.e during Q4 of the 8-cell stage. They also demonstrated the added value of time-lapse microscopy for determining the optimal timing for blastomere biopsy. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by the routine budget of our IVF unit. TRIAL REGISTRATION NUMBER: N/A.
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Blastómeros/citología , Fase de Segmentación del Huevo/citología , Diagnóstico Preimplantación/métodos , Biopsia/efectos adversos , Biopsia/métodos , Blastocisto/citología , Estudios de Cohortes , Implantación del Embrión , Desarrollo Embrionario , Femenino , Fertilización In Vitro , Humanos , Embarazo , Diagnóstico Preimplantación/efectos adversos , Estudios Retrospectivos , Inyecciones de Esperma Intracitoplasmáticas , Factores de Tiempo , Imagen de Lapso de TiempoRESUMEN
BACKGROUND: A previous small study suggested that Brain Network Activation (BNA), a novel ERP-based brain network analysis, may have diagnostic utility in attention deficit hyperactivity disorder (ADHD). In this study we examined the diagnostic capability of a new advanced version of the BNA methodology on a larger population of adults with and without ADHD. METHOD: Subjects were unmedicated right-handed 18- to 55-year-old adults of both sexes with and without a DSM-IV diagnosis of ADHD. We collected EEG while the subjects were performing a response inhibition task (Go/NoGo) and then applied a spatio-temporal Brain Network Activation (BNA) analysis of the EEG data. This analysis produced a display of qualitative measures of brain states (BNA scores) providing information on cortical connectivity. This complex set of scores was then fed into a machine learning algorithm. RESULTS: The BNA analysis of the EEG data recorded during the Go/NoGo task demonstrated a high discriminative capacity between ADHD patients and controls (AUC = 0.92, specificity = 0.95, sensitivity = 0.86 for the Go condition; AUC = 0.84, specificity = 0.91, sensitivity = 0.76 for the NoGo condition). CONCLUSIONS: BNA methodology can help differentiate between ADHD and healthy controls based on functional brain connectivity. The data support the utility of the tool to augment clinical examinations by objective evaluation of electrophysiological changes associated with ADHD. Results also support a network-based approach to the study of ADHD.
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Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Electroencefalografía/métodos , Potenciales Evocados/fisiología , Función Ejecutiva/fisiología , Inhibición Psicológica , Red Nerviosa/fisiopatología , Adolescente , Adulto , Electroencefalografía/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Adulto JovenRESUMEN
BACKGROUND: The clinical diagnosis and management of patients with sport-related concussion is largely dependent on subjectively reported symptoms, clinical examinations, cognitive, balance, vestibular and oculomotor testing. Consequently, there is an unmet need for objective assessment tools that can identify the injury from a physiological perspective and add an important layer of information to the clinician's decision-making process. OBJECTIVE: The goal of the study was to evaluate the clinical utility of the EEG-based tool named Brain Network Activation (BNA) as a longitudinal assessment method of brain function in the management of young athletes with concussion. METHODS: Athletes with concussion (n = 86) and age-matched controls (n = 81) were evaluated at four time points with symptom questionnaires and BNA. BNA scores were calculated by comparing functional networks to a previously defined normative reference brain network model to the same cognitive task. RESULTS: Subjects above 16 years of age exhibited a significant decrease in BNA scores immediately following injury, as well as notable changes in functional network activity, relative to the controls. Three representative case studies of the tested population are discussed in detail, to demonstrate the clinical utility of BNA. CONCLUSION: The data support the utility of BNA to augment clinical examinations, symptoms and additional tests by providing an effective method for evaluating objective electrophysiological changes associated with sport-related concussions.
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Traumatismos en Atletas/diagnóstico , Conmoción Encefálica/diagnóstico , Encéfalo/fisiopatología , Red Nerviosa/fisiopatología , Adolescente , Atletas , Traumatismos en Atletas/fisiopatología , Conmoción Encefálica/fisiopatología , Cognición/fisiología , Electroencefalografía , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Adulto JovenRESUMEN
Attentional selection in the context of goal-directed behavior involves top-down modulation to enhance the contrast between relevant and irrelevant stimuli via enhancement and suppression of sensory cortical activity. Acetylcholine (ACh) is believed to be involved mechanistically in such attention processes. The objective of the current study was to examine the effects of donepezil, a cholinesterase inhibitor that increases synaptic levels of ACh, on the relationship between performance and network dynamics during a visual working memory (WM) task involving relevant and irrelevant stimuli. Electroencephalogram (EEG) activity was recorded in 14 healthy young adults while they performed a selective face/scene working memory task. Each participant received either placebo or donepezil (5mg, orally) on two different visits in a double-blinded study. To investigate the effects of donepezil on brain network dynamics we utilized a novel EEG-based Brain Network Activation (BNA) analysis method that isolates location-time-frequency interrelations among event-related potential (ERP) peaks and extracts condition-specific networks. The activation level of the network modulated by donepezil, reflected in terms of the degree of its dynamical organization, was positively correlated with WM performance. Further analyses revealed that the frontal-posterior theta-alpha sub-network comprised the critical regions whose activation level correlated with beneficial effects on cognitive performance. These results indicate that condition-specific EEG network analysis could potentially serve to predict beneficial effects of therapeutic treatment in working memory.
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Mapeo Encefálico/métodos , Ondas Encefálicas/fisiología , Inhibidores de la Colinesterasa/farmacología , Potenciales Evocados/fisiología , Indanos/farmacología , Memoria a Corto Plazo/fisiología , Recuerdo Mental/fisiología , Reconocimiento Visual de Modelos/fisiología , Sustancias para Mejorar el Rendimiento/farmacología , Piperidinas/farmacología , Adulto , Ondas Encefálicas/efectos de los fármacos , Inhibidores de la Colinesterasa/administración & dosificación , Donepezilo , Potenciales Evocados/efectos de los fármacos , Femenino , Humanos , Indanos/administración & dosificación , Masculino , Memoria a Corto Plazo/efectos de los fármacos , Recuerdo Mental/efectos de los fármacos , Reconocimiento Visual de Modelos/efectos de los fármacos , Sustancias para Mejorar el Rendimiento/administración & dosificación , Piperidinas/administración & dosificación , Adulto JovenRESUMEN
INTRODUCTION: Analyses of miscarriage products indicate that the majority of aneuploidies in early developing embryos derive from errors occurring during maternal meiosis and the paternal contribution is less than 10%. Our aim was to assess the aneuploidy (mainly monosmies) frequencies at the earliest stages of embryo development, 3 days following fertilization during In vitro fertilization (IVF) treatments and to elucidate their parental origin. Later, we compared monosomies rates of day 3 to those of day 5 as demonstrated from Preimplantation Genetic Testing for Structural chromosomal Rearrangement (PGT-SR) results. METHODS: For a retrospective study, we collected data of 210 Preimplantation Genetic Testing for Monogenic Disorder (PGT-M) cycles performed between years 2008 and 2019.This study includes 2083 embryos, of 113 couples. It also included 432 embryos from 90 PGT-SR cycles of other 45 patients, carriers of balanced translocations. Defining the parental origin of aneuploidy in cleavage stage embryos was based on haplotypes analysis of at least six informative markers flanking the analyzed gene. For comprehensive chromosomal screening (CCS), chromosomal microarray (CMA) and next generation sequencing (NGS) was used. RESULTS: We inspected haplotype data of 40 genomic regions, flanking analyzed genes located on 9 different chromosomes.151 (7.2%) embryos presented numerical alterations in the tested chromosomes. We found similar paternal and maternal contribution to monosomy at cleavage stage. We demonstrated paternal origin in 51.5% of the monosomy, and maternal origin in 48.5% of the monosomies cases. CONCLUSION: In our study, we found equal parental contribution to monosomies in cleavage-stage embryos. Comparison to CCS analyses of PGT-SR patients revealed a lower rate of monosomy per chromosome in embryos at day 5 of development. This is in contrast to the maternal dominancy described in studies of early miscarriage. Mitotic errors and paternal involvement in chemical pregnancies and IVF failure should be re-evaluated. Our results show monosomies are relatively common and may play a role in early development of ART embryos.
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The risk of melanoma is higher in patients with Parkinson's disease (PD) than in the general population. Whether the association is disease related or treatment related is unclear. The objective of this study was to assess melanoma prevalence in PD patients in Israel using active dermatologic screening. Consecutive patients with idiopathic PD were recruited by 12 Israeli centers. A movement disorder specialist assessed the severity of PD and obtained a medical, neurological, and medication history. Subsequently, a dermatologist assessed melanoma risk factors, recorded a dermatologic history, proactively performed a whole-body skin examination, and biopsied suspicious skin lesions. Of the enrolled patients (n = 1,395, mean age 69.5 ± 10.6 years, mean PD duration 7.3 ± 6.0 years), 95.3% were treated with dopaminergic agents. Biopsies revealed 8 patients with melanoma in situ and 1 with invasive malignant melanoma; 14 patients reported a melanoma prior to enrollment. The observed 5-year limited duration prevalence of melanoma in PD patients was 4.4 times greater (95% CI 2.6-7.6) than expected from melanoma prevalence in an age- and sex-matched cohort from the Israel National Cancer Registry. The increase was accounted for by an elevated prevalence of melanoma in situ [relative risk 12.5 (95% CI 6.7-23.2)]. Occurrence of melanoma did not correlate with levodopa therapy or time of onset of PD. Melanoma prevalence in PD patients was higher than expected in the general Israeli population. This was not related to levodopa treatment. PD patients should be actively screened for melanoma on a routine basis.
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Melanoma/epidemiología , Enfermedad de Parkinson/epidemiología , Neoplasias Cutáneas/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Antiparkinsonianos/uso terapéutico , Estudios de Cohortes , Femenino , Humanos , Israel/epidemiología , Masculino , Melanoma/diagnóstico , Persona de Mediana Edad , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/tratamiento farmacológico , Prevalencia , Neoplasias Cutáneas/diagnósticoRESUMEN
Bioinformatics is a new scientific field. It applies computational and analysis tools to the capture, analyze and interpret large quantities of biological data. To understand genomic information, comparative analysis of data obtained is crucial. Primary physicians are dauntingly being implored to evaluate patients genetically, and analyze the results received. We depict online tools available for defining the clinical characteristics of a patient (phenotype), assisting in compiling them into a tentative genetic clinical diagnosis. The subsequent step is to then learn the patient's genotype and how to curate a specific genetic copy number or sequence variant. The online resources available to assist in this arduous process are described.
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Biología Computacional , Estudios de Asociación Genética/métodos , Genoma Humano/genética , Genómica , Bases de Datos Genéticas , Genotipo , Humanos , Internet , FenotipoRESUMEN
BACKGROUND: Pain perception is typically assessed using subjective measures; an objective measure of the response to pain would be valuable. In this study, Brain Network Activation (BNA), a novel multivariate pattern analysis and scoring algorithm, was applied to event-related potentials (ERPs) elicited by cortical responses to brief heat stimuli. Objectives of this study were to evaluate the utility of BNA as a quantitative and qualitative measure of cortical response to pain. METHODS: Contact Heat Evoked Potentials (CHEPs) data were collected from 17 healthy, right-handed volunteers (10 M, 7F) using 5 different temperatures (35, 41, 46, 49 and 52 °C). A set of spatio-temporal activity patterns common to all the subjects in the group (Reference Brain Network Model; RBNM) was generated using the BNA algorithm, based on evoked responses at 52 °C. RESULTS: Frame by frame 'unfolding' of the brain network across time showed qualitative differences between responses to painful and non-painful stimuli. Brain network activation scores were shown to be a better indicator of the individual's sensitivity to pain when compared to subjective pain ratings. Additionally, BNA scores correlated significantly with temperature, demonstrated good test-retest reliability, as well as a high degree of sensitivity, specificity and accuracy in correctly categorizing subjects who reported stimuli as painful. CONCLUSIONS: These results may provide evidence that the multivariate analysis performed with BNA may be useful as a quantitative, temporally sensitive tool for assessment of pain perception.
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Encéfalo/fisiopatología , Electroencefalografía/métodos , Potenciales Evocados/fisiología , Red Nerviosa/fisiopatología , Dimensión del Dolor/métodos , Dolor/fisiopatología , Adolescente , Adulto , Femenino , Calor , Humanos , Masculino , Estimulación Física , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
Heparin was found to be the most potent inhibitor of rat ovarian luteinizing hormone-sensitive adenylate cyclase (I50 = 2 microgram/ml) when compared to other naturally occurring glycosamin oglycans. This inhibition was also apparent when this enzyme was stimulated by follicle-stimulating hormone or prostaglandin E2. Heparin was also found to inhibit glucagon-sensitive rat hepatic adenylate cyclase, and the prostaglandin E1-sensitive enzyme from rat ileum and human platelets. In contrast, heparin stimulated the dopamine sensitive adenylate cyclase from rat caudate nucleus. The sulfated polysugar dextran sulfate exerts similar effects on adenylate cyclase activity of the rat ovary and was shown to inhibit hormone binding to rat ovarian plasma membrane in a manner similar to that exerted by heparin. In contrast to heparin, dextran sulfate inhibited dopamine-sensitive adenylate cyclase from rat caudate nucleus.
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Adenilil Ciclasas/metabolismo , Dextranos/farmacología , Glicosaminoglicanos/farmacología , Animales , Plaquetas/enzimología , Núcleo Caudado/enzimología , Membrana Celular/enzimología , Gonadotropina Coriónica/farmacología , Femenino , Hormona Folículo Estimulante/farmacología , Humanos , Íleon/enzimología , Mucosa Intestinal/enzimología , Cinética , Hígado/enzimología , Hormona Luteinizante/farmacología , Masculino , Ovario/enzimología , Prostaglandinas E/farmacología , RatasRESUMEN
A unique cast model of the placenta in a rare case of feto-feto-fetal triplet transfusion syndrome (FFFTTS) allowed the demonstration of why the transfusion syndrome developed in one fetus and not in the other two in that single placenta. The vasculature anatomy of a monochorionic triamniotic triplet placenta with FFFTTS of three healthy infants (one donor, two recipients) born in the 35th week of gestation was cast by means of dental casting materials. After the cast hardened, the tissue was corroded, revealing the cast blood vessels. The diameters and lengths of the chorionic blood and intraplacental vessels of the cast placenta were measured with a digital caliper. The cast revealed two artery-artery (A-A) anastomoses on the chorionic plate between the two recipients and the donor. Seven artery-vein (A-V) deep anastomoses connected only the arteries of the donor and the veins of the two recipients. The blood vessel connections among the fetuses allowed the evaluation of a pathologic case with its own control in a single placenta. From the vascular appearance, we speculate that the A-A anastomoses between the two fetuses protected them from developing blood transfusions, but that the A-V anastomoses contributed to their development.
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Transfusión Feto-Fetal/etiología , Transfusión Feto-Fetal/patología , Placenta/patología , Trillizos , Adulto , Amnios/patología , Anastomosis Arteriovenosa/patología , Corion/patología , Molde por Corrosión , Femenino , Humanos , Recién Nacido , Modelos Anatómicos , Embarazo , Cordón Umbilical/patologíaRESUMEN
In a prospective study we evaluated the relationship of level of consciousness to hemispheric side of lesion following acute cerebrovascular injury. Fifty-seven percent of patients with left hemispheric lesions had initial impairment of consciousness, in contrast to 25% with right-sided damage.
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Trastornos Cerebrovasculares/fisiopatología , Estado de Conciencia , Dominancia Cerebral , Trastornos Cerebrovasculares/líquido cefalorraquídeo , Lateralidad Funcional , HumanosRESUMEN
We measured the kinetic constants for the unidirectional influx of L-DOPA into red blood cells of patients with Parkinson's disease (seven patients), Huntington's disease (seven patients), and other extrapyramidal diseases (11 patients), and in five controls. Influx consisted of two components with low affinity and high exchange capacity. In individual subjects, the L-DOPA concentration giving half-maximal influx (Km) varied between 0.04 and 2.19 mM, and the maximum velocity (Vmax) of the saturable transport component was between 20 and 578 mumol/l cell water/h, which is compatible with the neutral amino acids of low affinity for the transport system. The range of Kd (the first-order rate constant for the unsaturable component) was between 0.11 and 0.36 hour-1. There was no gross deficit of the L-DOPA uptake process in patients with Parkinson's disease, Huntington's disease, dystonia, or other extrapyramidal diseases.
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Eritrocitos/metabolismo , Enfermedad de Huntington/metabolismo , Levodopa/metabolismo , Enfermedad de Parkinson/metabolismo , Transporte Biológico , Humanos , Enfermedades Neuromusculares/metabolismoRESUMEN
A brain-damaged man was unable to appreciate the nature of objects and meaningful nonverbal symbols presented visually, although he could see, draw, describe, and match these stimuli. He had no difficulty understanding visually presented words. Auditory and tactile recognition of both verbal and nonverbal stimuli were normal. Our findings provide evidence that two neuropsychologic mechanisms were responsible for this disorder. One was an interhemispheric visual-verbal disconnection; the other was a specific categorization defect for visual, nonverba, meaningful stimuli. Neither mechanism alone was sufficient; both were necessary.
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Agnosia , Asociación , Percepción Visual , Agnosia/complicaciones , Percepción Auditiva , Daño Encefálico Crónico/complicaciones , Confusión , Dislexia Adquirida/complicaciones , Electroencefalografía , Humanos , Inteligencia , Masculino , Memoria , Persona de Mediana Edad , Reconocimiento Visual de Modelos , Pruebas Psicológicas , Síndrome , Tacto , Campos Visuales , Escalas de WechslerRESUMEN
In a patient with associative visual agnosia without alexia, there was bilateral infarction in the distribution of the posterior cerebral arteries, with corticosubcortical lesions in both occipitotemporal regions, sparing the corpus callosum. Bilateral loss of visual-limbic connections may underlie associative visual agnosia, and bilateral lesions of the inferior longitudinal fasciculi may be the necessary and sufficient lesions for this syndrome. Alexia was absent in this case, perhaps because the corpus callosum was intact.
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Agnosia/patología , Percepción Visual/fisiología , Percepción Auditiva/fisiología , Arterias Cerebrales/patología , Corteza Cerebral/patología , Infarto Cerebral/patología , Hipocampo/patología , Humanos , Arteriosclerosis Intracraneal/patología , Masculino , Persona de Mediana Edad , Orientación/fisiología , Tacto/fisiologíaRESUMEN
Refractory response to dopamine (DA) agonists is a common problem in the treatment of Parkinson's disease. In rats with unilateral lesions of the substantia nigra, denervation induced significant increases in striatal 3(H)-spiperone binding sites ipsilateral to the lesion. Chronic treatment with levodopa or with pergolide mesylate significantly decreased the number of 3(H)-spiperone striatal binding sites. Agonist-induced decreases were approximately equivalent in intact and denervated striata and did not appear to be affected by lesions. These results suggest that the poor response to DA agonist in certain parkinsonian patients with chronic drug exposure may be mediated by drug-induced DA receptor down-regulation.
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Cuerpo Estriado/efectos de los fármacos , Ergolinas/farmacología , Levodopa/farmacología , Receptores Dopaminérgicos/efectos de los fármacos , Animales , Cuerpo Estriado/metabolismo , Desnervación , Ergolinas/metabolismo , Levodopa/metabolismo , Masculino , Enfermedad de Parkinson/tratamiento farmacológico , Pergolida , Ratas , Ratas Endogámicas , Receptores Dopaminérgicos/metabolismoRESUMEN
Chronic administration of the benzodiazepine, clonazepam, increased the number of [3H]5-hydroxytryptamine (5-HT1) binding sites in the frontal cortex of the rat. The increase reflected a change in the maximum density of binding sites (Bmax) with no change in ligand affinity (Kd). Increased binding occurred after continued exposure (10 days) to large (5.0 mg/kg) doses of clonazepam. The changes in [3H]5-HT binding were regional in that they occurred in membranes from the frontal cortex but not the brainstem. The effects were also at least partially selective for 5-HT receptors since the binding of the beta-adrenergic radioligand, [3H]dihydroalprenolol, was not affected by clonazepam. A second benzodiazepine, diazepam, did not affect the binding of [3H]5-HT at doses of 30 mg/kg per day. The latter data suggest that the effects of benzodiazepines on serotonin 5-HT1 receptors are unique to clonazepam.
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Benzodiazepinonas/farmacología , Clonazepam/farmacología , Lóbulo Frontal/efectos de los fármacos , Receptores de Serotonina/efectos de los fármacos , Animales , Lóbulo Frontal/análisis , Ácido Hidroxiindolacético/análisis , Masculino , Ratas , Ratas Endogámicas , Receptores de Serotonina/análisis , Serotonina/análisis , Estimulación QuímicaRESUMEN
The ergot derivative pergolide was evaluated as a dopamine agonist using various behavioral and biochemical analyses. Spontaneous motor activity was decreased by small doses (0.1 mg/kg) of pergolide and increased with larger doses (above 0.5 mg/kg). Hypermotility after larger doses persisted for as long as 24 hr and was succeeded by a period of hypomotility. The doses of drug, sufficient to produce hypermotility, also produced stereotypy. With repeated daily injections (2 weeks), the period of hypermotility decreased and the ensuing period of hypomotility increased. Stereotyped behavior was similarly affected. Chronic administration of pergolide did not alter the magnitude of the behavioral responses. Levels of the dopamine (DA) metabolites, dihydroxyphenylacetate (DOPAC) and homovanillic acid (HVA), in the striatum and mesolimbic regions were decreased during the periods of hypermotility but returned to control levels during subsequent hypomotility. Activation of putative inhibitory presynaptic dopamine receptors by pergolide was studied by following accumulation of DOPA in rats treated with the dopamine neuron inhibiting agent, gamma-butyrolactone (GBL) and a DOPA-decarboxylase inhibitor. Pergolide significantly inhibited both striatal and mesolimbic accumulation of DOPA. In contrast, with changes in behavioral and metabolic indices, pergolide-induced inhibition of tyrosine hydroxylase was not affected by chronic treatment with pergolide. On the basis of both behavioral and biochemical data it is proposed that pergolide acts as a dopamine agonist with particularly long-lasting effects.
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Antiparkinsonianos/farmacología , Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Ergolinas/farmacología , Sistema Límbico/metabolismo , Actividad Motora/efectos de los fármacos , Receptores Dopaminérgicos/fisiología , Ácido 3,4-Dihidroxifenilacético/metabolismo , 4-Butirolactona/farmacología , Animales , Dopamina/biosíntesis , Ácido Homovanílico/metabolismo , Humanos , Masculino , Pergolida , Ratas , Ratas Endogámicas , Conducta Estereotipada/efectos de los fármacos , Sustancia Negra/fisiologíaRESUMEN
The effects of the catechol-O-methyltransferase (COMT) inhibitor 3',4'-dihydroxy-2-methyl-propriophenone (U-0521) were studied in red blood cells (RBC) and corpus striatum in the rat. In vitro U-0521 inhibited RBC COMT activity in a dose-dependent manner with an IC50 of 6 x 10(-6)M. In vivo maximum inhibition (90%) of enzyme activity in RBC was obtained with 250 mg/kg with a peak effect at 5 min and enzyme recovery within 90 min. In U-0521-pretreated rats L-3,4-dihydroxyphenylalanine (L-DOPA) accumulation in RBC and corpus striatum, after injection of L-DOPA, was significantly higher than in nonpretreated rats. The use of COMT inhibitor along with L-DOPA may be of benefit in the treatment of Parkinson's disease.
Asunto(s)
Inhibidores de Catecol O-Metiltransferasa , Cuerpo Estriado/metabolismo , Eritrocitos/metabolismo , Levodopa/metabolismo , Propiofenonas/farmacología , Animales , Catecol O-Metiltransferasa/metabolismo , Relación Dosis-Respuesta a Droga , Levodopa/administración & dosificación , Levodopa/sangre , Masculino , Propiofenonas/administración & dosificación , Ratas , Ratas EndogámicasRESUMEN
In 2 elderly male patients, a progressive neurologic deficit and alteration of consciousness developed following substantial head trauma succeeded by an asymptomatic "lucid" interval. The sequence of events and the associated electroencephalographic, echoencephalographic and cerebrospinal fluid findings strongly suggested the presence of an extracerebral hematoma. The cerebral angiographic study, however, disclosed complete occlusion of the extracranial portion of the internal carotid artery in both patients. This report stresses the diagnostic difficulties sometimes encountered in relation to stroke patients.