The obstructive sleep apnea syndrome is characterized by the occurrence of cyclic snoring and frequent apneic episodes during sleep, with consequent hypoxia and hypercapnia. Obstructive sleep apnea syndrome is associated with excess daytime sleepiness, depression, and an increased incidence of ischemic cardiopathy, cardiac arrhythmias, systemic hypertension and brain infarction. Hypoglossal motoneurons, which innervate extrinsic and intrinsic muscles of the tongue, play a key role in maintaining the patency of the upper airway and in the pathophysiology of obstructive sleep apnea syndrome.
View Article and Find Full Text PDFObjective: To analyze the factors involved in the functional prognosis of stroke patients three months after onset.
Patients And Methods: We made a prospective study of 288 patients with non-transient strokes who had been admitted consecutively to our hospital. Data was collected on a standardized questionnaire: age, sex, risk factors, latency of admission, interval of neurological attention (INA), severity of defect (classified on the Scandinavian scale: slight-moderate: SSS > 30/serious: SSS < or = 30), stay in hospital, development of complications and previous quality of life, after seven and ninety days.
The present study was undertaken to identify trigeminal premotor interneurons that become activated during carbachol-induced active sleep (c-AS). Their identification is a critical step in determining the neural circuits responsible for the atonia of active sleep. Accordingly, the retrograde tracer cholera toxin subunit B (CTb) was injected into the trigeminal motor nuclei complex to label trigeminal interneurons.
View Article and Find Full Text PDFWeakly electric fish generate meaningful electromotor behaviors by specific modulations of the discharge of their medullary pacemaker nucleus from which the rhythmic command for each electric organ discharge (EOD) arises. Certain electromotor behaviors seem to involve the activation of specific neurotransmitter receptors on particular target cells within the nucleus, i.e.
View Article and Find Full Text PDFJ Neurophysiol
October 1999
The pontine microinjection of the inhibitory neurotransmitter GABA and its agonist induced prolonged periods of wakefulness in unanesthetized, chronic cats. Conversely, the application of bicuculline, a GABA(A) antagonist, resulted in the occurrence of episodes of rapid eye movement (REM) sleep of long duration. Furthermore, administration of antisense oligonucleotides against glutamic acid decarboxylase (GAD) mRNA into the same area produced a significant decrease in wakefulness and an increase in REM sleep.
View Article and Find Full Text PDFThe technology is available to produce fuel ethanol from renewable lignocellulosic biomass. The current challenge is to assemble the various process options into a commercial venture and begin the task of incremental improvement. Current process designs for lignocellulose are far more complex than grain to ethanol processes.
View Article and Find Full Text PDFJ Neurophysiol
September 1999
In the present report, we provide evidence that mesencephalic trigeminal (Mes-V) sensory neurons, a peculiar type of primary afferent cell with its cell body located within the CNS, may operate in different functional modes depending on the degree of their membrane polarization. Using intracellular recording techniques in the slice preparation of the adult rat brain stem, we demonstrate that when these neurons are depolarized, they exhibit sustained, high-frequency, amplitude-modulated membrane potential oscillations. Under these conditions, the cells discharge high-frequency trains of spikes.
View Article and Find Full Text PDFThe tolerance to freezing and thawing of Leucodon sciuroides, a moss growing in mountainous areas of the Mediterranean (south-east Spain), was investigated by means of CO gas exchange, modulated chlorophyll (Chl) a fluorescence and pigment analysis by high-performance liquid chromatography. Evidence is presented for freezing-induced decreases in CO fixation that enhance non-radiative dissipation of absorbed light energy, a process which protects the photosynthetic apparatus. The photosynthetic apparatus of L.
View Article and Find Full Text PDFBackground: Peak oxygen uptake (peak VO(2)) is a reference parameter in the assessment of functional capacity of patients with chronic heart failure, but the procedure for cardiopulmonary exercise testing with expired gas analysis is complex and expensive, so more simple and available methods are desirable.
Methods: We compared the usefulness of a time-limited walk test, the 6-minute walk test (6-MT), with that of a symptom-limited walk test, the shuttle walk test (SWT), in the evaluation of patients with moderate to severe chronic heart failure. We prospectively studied 46 clinically stable patients in New York Heart Association class II to IV heart failure with left ventricular ejection fraction <40% (aged 53 +/- 10 years, ejection fraction 23% +/- 8%, New York Heart Association functional class 2.
Introduction And Objective: We present a diagnostic decision tree for the correct use of neuropsychological evaluation techniques in head injury. Our aim is to avoid extensive, intensive use of unnecessary tests and measurements or lapses into diagnostic error which often accompany cognitive dysfunction when 'superficial' 'undirected' studies are done.
Development: It is essential to select the neuropsychological, neuroconductal and psychosocial evaluation tests which are most suitable in each case and establish a reliable diagnosis of the functional, cognitive, emotional and psychosocial conditions of the patient.
Meningiomas are tumors in arachnoid cells which represent up to one fifth of all intracranial tumors and up to a quarter of spinal neoplasias. Although meningiomas have classically been considered to be benign tumors, it has also been well-established that they show a heterogeneous clinical outcome. To the best of our knowledge no study has yet been performed in which the independent prognostic value of both DNA ploidy and cell cycle has been simultaneously assessed in a large series of meningioma tumors.
View Article and Find Full Text PDFThe present study was undertaken to determine whether age-dependent changes in axonal conduction velocity occur in pyramidal tract neurons. A total of 260 and 254 pyramidal tract neurons were recorded extracellularly in the motor cortex of adult control and aged cats, respectively. These cells were activated antidromically by electrical stimulation of the medullary pyramidal tract.
View Article and Find Full Text PDFObjective: To determine the main etiological mechanisms of symptomatic epilepsy and its frequency according to age.
Patients And Methods: We made a retrospective analysis of 208 patients admitted during a period of four and a half years, studying the variables: age, sex and type of seizures: simple partial, secondarily generalized partial, complex partial, tonic-clonic, generalized tonic, and also EEG and neuroimaging.
Results: The main etiological mechanisms found were: vascular (31.
Objectives: The response to the different antimigraine medications is variable. In this study we have analysed the profile of prescription of these antimigraine medications, both preventive and symptomatic, by a group of spanish neurologists and examined the subjective efficacy of these compounds.
Patients And Methods: Neurologists from 7 hospitals in different spanish regions interviewed 305 patients (at least 40 per hospital) who met migraine diagnostic criteria.
A case of a giant aneurysm of the right middle cerebral artery treated with Guglielmi detachable coils is reported. Extracranial to intracranial bypass had previously been performed and surgical trapping had been attempted. During the endovascular procedure, balloon test occlusion of the middle cerebral artery was performed in order to demonstrate clinical and angiographic tolerance to parent vessel occlusion.
View Article and Find Full Text PDFDuring active sleep or carbachol-induced motor inhibition, electrical stimulation of the medullary nucleus reticularis gigantocellularis (NRGc) evoked large amplitude, glycinergic inhibitory postsynaptic potentials (IPSPs) in cat motoneurons. The present study was directed to determine whether these IPSPs, that are specific to the state of active sleep, are modulated by opioid peptides. Accordingly, intracellular recordings were obtained from lumbar motoneurons of acute decerebrate cats during carbachol-induced motor inhibition while an opiate receptor antagonist, naloxone, was microiontophoretically released next to the recorded cells.
View Article and Find Full Text PDFEnferm Infecc Microbiol Clin
November 1998
Electrical stimulation of the nucleus pontis oralis during wakefulness enhances somatic reflex activity; identical stimuli during the motor atonia of active (rapid eye movement) sleep induces reflex suppression. This phenomenon, which is called reticular response-reversal, is based upon the generation of excitatory postsynaptic potential activity in motoneurons during wakefulness and inhibitory postsynaptic potential activity during the motor atonia of active sleep. In the present study, instead of utilizing artificial electrical stimulation to directly excite brainstem structures, we sought to examine the effects on motoneurons of activation of sensory pathways by exogenously applied stimuli (auditory) and by stimulation of a peripheral (sciatic) nerve.
View Article and Find Full Text PDFPeripheral neuropathy (PN) is the main side effect with cycles of paclitaxel at standard doses (175 mg/m2 for 21 days). Administration of a single high-dose paclitaxel (HDP) is a novel approach for the treatment of cancer. We have prospectively measured neurotoxicity induced by HDP during a phase I trial.
View Article and Find Full Text PDFBackground: Migraine is the main reason for neurological consultation.
Objectives: To analyse the profile of the patient with migraine attending the Neurological Services of our country.
Patients And Methods: Neurologists from 7 hospitals in different spanish regions interviewed 305 patients (at least 40 per hospital) who met migraine diagnostic criteria.
Unlabelled: We undertook an epidemiologic study to ascertain the prevalence of multiple sclerosis (MS) in the Sanitary District of Calatayud, in the north-east of Spain.
Methods: The study was performed from October 1990 to July 1996. The total number of residents in the area was 58,591.
The traditional method for analyzing passive electrical data from neurons when specific morphological data are unavailable consists of decomposing the voltage response of the cell into a series of exponential functions (the peeling method) and substituting the time constants of these exponential functions into equations derived from cable theory (Rall W, Core conductor theory and cable properties of neurons. In: Handbook of Physiology. The Nervous System.
View Article and Find Full Text PDFIn the present study, we examined the age-related intra-axonal accumulation of neurofilaments in the dorsal column nuclei of the cat by using immunohistochemical techniques combined with light and electron microscopy. Light microscopic analysis revealed oval or circular immunostained structures in the dorsal column nuclei of old cats. These immunostained structures were not observed in the material obtained from adult controls.
View Article and Find Full Text PDFThe overuse of analgesics in patients with chronic daily headache (CDH) perpetuates and worsens the headache. The aim of this study was to evaluate the clinical response to withdrawal of analgesics and to preventive treatment in a group of patients with CDH. Eighty-four patients who were taking daily symptomatic medications, and suffering from CDH were studied.
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