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Biomedical subjects

J Pastor

Publications and source records attributed to J Pastor.

At least 127 records · Page 7Linked to original sources
PubMed1977

Dose-time pattern of the hypercalcemic response to calcium infusion in the dog.

Forty-five tests were performed to study blood total [Ca] response to a 2-hours IV calcium gluconate infusion, in five conscious dogs. Calcium doses were : 2.45 ; 4.50;6.19 and 9.00 mumole kg--u min-1 ; saline was used as control. Blood samples were collected every 20 minutes and calcaemia determined by atomic absorption spectrophotometry at 422.7 nm. No plateau was reached except with lowest dose. At each Ca dose, successive calcaemia levels can be fitted by a straight line and the regression calculated. With studied doses, calculated slopes were : 3.6 ; 8.3 ; 11.8 and 19.1 mumole l--1 min--1 respectively ; these slopes were found to be significantly different from each other. A linear dose-response relationship was calculated between blood [Ca] increase rate and Ca dose : Y = --3.01 + 2.44 X (mumole l--1 min-1 increase rate per mumole kg--1 min-1 Ca dose). Correspondence analysis emphazises the influence of zero time calcaemia.

Animals↗
PubMed1975

Mediastinoscopy in the surgical management of lung carcinoma.

Up to December 1973, we had performed 100 mediastinoscopies for lung carcinoma. Fifty-two were positive and 48 negative. In 80 cases there was clinical or radiological suspicion of mediastinal invasion. With radiological evidence of mediastinal node involvement exploration was positive in 32 out of 35 cases, when chest radiography findings were equivocal in 19 out of 45, and when radiology of the mediastinum was normal in only one of 20 cases. Mediastinoscopy was more frequently positive when the carcinoma was oat-cell or anaplastic. Of 48 patients with negative biopsies, 41 were explored. In 26 the carcinoma extended beyond the lung. In 1973 we circularized 83 thoracic surgeons concerning (1) the use of mediastinoscopy for patients with lung carcinoma assessed for surgery, (2) the significance of mediastinal node involvement, (3) the results of radiotherapy alone in patients rejected for surgery, and (4) the survival rate in patients with positive mediastinal nodes treated with surgery alone or together with radiotherapy. The replies to the questionnaire are summarized. The authors emphasize the usefulness of mediastinoscopy but state that care must be taken when deciding to withhold operation for a possible cure.

Biopsy↗
PubMed1975

Surgical stabilization of traumatic flail chest.

Since 1970 we have stabilized the ribs to correct paradoxical movement of the chest wall in chest injuries, using an original technique, in order to avoid as far as possible the need for long-term chest wall stabilization by intermittent positive pressure respiration (IPPR). The technical details of surgical stabilization are described, and the different types of stainless steel struts are shown. Type I was originally used either as an intramedullary nail or as an external brace. Types II and III were designed for external fixation of the strut to the rib. Treatment of 29 patients with severe flail chest, classified into four groups is shown: group I was treated by IPPR, group II by IPPR plus surgical stabilization, group III by surgical stabilization only, and group IV by surgical stabilization after exploratory thoracotomy. The clinical results are discussed. We conclude that surgical stabilization of the paradoxial movement of the chest wall can avoid the use of the respirator or at least reduce the interval of IPPR to a short period during the initial recovery from trauma. Using type III struts, we have obtained stabilization of the flail chest in all cases even in patients with severe anterior paradoxical movement. The patients' tolerance of surgical stainless steel struts was good.

Humans↗
PubMedDate not supplied

Electrically induced blink reflex and facial motor nerve stimulation in beagles.

Electrophysiologic assessment of the blink reflex test and the muscle-evoked potentials evoked by stimulation of the facial nerve were performed in 15 healthy adult Beagles before and after supraorbital (trigeminal) and facial anesthetic nerve blocks performed by lidocaine injections. Unilateral electrical stimulation of the supraorbital nerve elicited 2 ipsilateral (R1 and R2) and a contralateral (Rc) reflex muscle potential in orbicularis oculi muscles. Electrical stimulation of the facial nerve elicited 2 muscle potentials (a direct response [D] and a reflex faciofacial response [RF]) in the ipsilateral orbicularis oculi muscle. Anesthetic block of the left supraorbital nerve resulted in bilateral lack of responses upon left supraorbital nerve stimulation, but normal responses in right and left orbicularis oculi muscles upon right supraorbital stimulation. Right facial anesthetic block produced lack of responses in the right orbicularis oculi muscle regardless the side of supraorbital nerve stimulation. Results of this study demonstrate that the blink reflex can be electrically elicited and assessed in dogs. Reference values for the blink reflex responses and for the muscle potentials evoked by direct facial nerve stimulation in dogs are provided. The potential usefulness of the electrically elicited blink reflex test in the diagnosis of peripheral facial and trigeminal dysfunction in dogs was demonstrated.

Animals↗
PubMedDate not supplied

[Reflex benign myoclonic epilepsy of childhood. Apropos of a new case].

INTRODUCTION: Recently a series of cases has been reported characterized by myoclonic crises similar to those occurring in benign myoclonic epilepsy of childhood. However, these crises only occurred after unexpected tactile or auditory stimuli. These clinical conditions represent a new epileptic syndrome, which is age-dependent and has been called benign myoclonic epilepsy of childhood. CLINICAL CASE: We present the case of a 12 month old girl with myoclonic crises which occurred only after auditory or tactile stimuli. The myoclonia could be set off whilst awake or asleep. No other types of crises or neurological changes were seen. A brother of the patient had had febrile convulsions. The EEG recorded during the crises showed generalized brief spike-and-wave discharges at 3 cycles/second. The intercritical EEG was normal whilst awake, but during sleep showed brief generalized discharges. After treatment with valproate was started the crises became less frequent. CONCLUSIONS: The case we describe is similar to those described by Ricci et al in 1995. We, therefore, consider it to fit the concept of reflex myoclonic epilepsy of childhood of benign character. We consider that this condition should be differentiated from other reflex epilepsies and epileptic syndromes with a predominance of myoclonia, including benign myoclonic epilepsy of childhood.

Acoustic Stimulation↗
PubMedDate not supplied

[Lhermitte-Duclos disease associated with tuberous sclerosis. A case report and review of literature].

INTRODUCTION: Lhermitte-Duclos disease is a rare disorder of the cerebellum of unknown origin in which dysplasic thickening of the cerebellar convolutions is seen. It usually occurs in young adults. Currently it is included in the phacomatosis group of disorders. CLINICAL CASE: A 19 year old woman attended the Emergency Department complaining of progressive orthostatic headache for the previous three months. On examination there were striking facial micronodular lesions suggestive of angiofibromas, a hypo-pigmented macula in the inframammary region and a hyperpigmented 'café-au-lait' macula in the right hypochondrium. On computerized tomography there was tetraventricular hydrocephalia. Cerebral magnetic resonance showed significant descent of the tonsils, hypertensive hydrocephalia and a lesion in the left cerebellum, apparently laminar hyperintensity in DP and T2, with thickening of some folia, not enhanced by intravenous contrast and suggestive of a dysplasic gangliocytoma. Laboratory investigations showed subclinical hypothyroidism. Other investigations were normal. The patient was treated by implanting a ventriculo-peritoneal shunt which has relieved the symptoms to date. CONCLUSIONS: Lhermitte-Duclos disease is probably not a single anatomo-clinical condition, assuming that it may be a cerebellar hamartoma associated with a phacomatosis with few clinical signs, whether it be Cowden's disease, tuberous sclerosis as in this case or an 'overlapping' syndrome. The magnetic resonance findings are necessary and sufficient for the diagnosis of Lhermitte-Duclos disease.

Adult↗
PubMedDate not supplied

[Biophysical foundations of the neuronal activity].

OBJECTIVE: It is sought to expose in a simple but rigorous way the fundamental basis of the classical biophysics. DEVELOPMENT: I start from the basic properties of a simple system (two solutions separated by a semipermeable membrane) in order to analyze the process of development of differences of potential. It is analyzed with special interest the development of the Nernst and Nernst-Planck equations. Then it is studied how this difference potential can originate, with different ionic species, the resting potential (Goldman, Hodgkin and Katz model). The next step consists in to analyze how the action potential arises. To do this, it will be of capital importance the mathematical model developed by Hodgkin and Huxley in the fifties; for it will be analyzed it thoroughly. Finally, some properties of the ionic channels will be commented that symbolize the biological implementation of the previous model. CONCLUSION: The fundamental property of the nervous system that constitutes its biological sense is the handling of the information in a quick and sure way. This information codes it basically in form of potentials and its changes. For it, it would be important for clinical neurophysiologists, neurologists, neurosurgeons and psychiatrists to understand the mechanisms that underlie into the behavior of the nervous system.

Animals↗
PubMedDate not supplied

[Comparative analysis of the clinical history and polysomnography in sleep disorders. Diagnostic relevance of polysomnography].

INTRODUCTION: The incidence of associate pathologies has been studied during the sleep, as well as the diagnostic efficiency of the clinical history. PATIENTS AND METHODS: Patients (n = 136) remitted by diverse services, have been studied. It has been carried out a complete polysomnography, as well as other supplementary studies (anxiety and depression tests, excessive daytime sleepiness Epworth's test, EEG and sleep notebook). RESULTS: The most common symptom turned out to be the primary snores, followed by the excessive daytime sleepiness and apneas. The results of the excessive daytime sleepiness Epworth's test and the anxiety and depression tests were not useful to differ among pathologies, not even between pathologies and patients with normal sleep. The percentage of diagnosis of suspicion confirmed by the polysomnography was of 39.7%, while in 11% of the total of patients it was observed the existence of more than a pathology of the sleep. In 49.3% of the cases the polysomnographic diagnosis was completely different from the diagnosis of suspicion. Among the patients with clinic suspicion of apnoea, in 48.3% of the cases the existence of the same one was verified, although in 14.6% it was associated with other pathologies. In 51.7% of the patients it was not possible to confirm this pathology. CONCLUSIONS: The clinical history is not enough for the diagnosis of the pathologies of the sleep. On the other hand, the existence of associate pathologies diminishes the value of several 'screening-methods'. Therefore, it is fundamental to carry out a complete polysomnography in all the patients that present any sleep disorder on the part of doctors that approach the problem of the sleep in a global way and not only thinking in the possible existence of syndrome of sleep apnoea.

Adolescent↗
PubMedDate not supplied

[Statistical analysis of repetitive nerve stimulation test].

INTRODUCTION: Statistical properties of Repetitive Nerve Stimulation test (RNS) are studied for different variables (forth to first potentials ratio of CMAP) together with two new variables (trends of area and amplitude for series of CMAP) OBJECTIVE: To compare the variables commonly used, in order to define the best statistical properties and, in the other hand, investigate if the new variables (trends in area and amplitude) could be useful for the study of neuromuscular transmission pathology. SUBJECTS AND METHODS: Statistical properties of voltage (V4/V1(V)), area of CMAP (V4/V1(a)) and slopes of regression lines of voltage (m(V)) and area (m(a)) measures are determined for runs of 3, 10, 15 and 20 Hz series of stimuli in 13 men and 17 women healthy volunteers. RESULTS: 1) The sample fits well to a normal distribution; 2) The variables that measure tendencies in CMAP series, can be reasonably fitted to linear regression functions; 3) Differences between sex and age have been not found; 4) Variables measuring tendencies have been the most stables, specially m(a); 5) The variable that fits better to normal distribution is m(V); 6) All variables behave linearly with respect frequency of stimulation. CONCLUSIONS: 1) Neuromuscular transmission is a particularly stable physiologic function; 2) The most used variable in clinical neurophysiology laboratories, V4/V1(V) have the worst statistical properties, showing a very significant variability; 3) Trends measures (m(a)) and m(V)) show very satisfactory statistical properties; this implies that these could be very useful for the study of neuromuscular transmission diseases.

Data Interpretation, Statistical↗