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Biomedical subjects

F Guirado

Publications and source records attributed to F Guirado.

5 recordsLinked to original sources

Metabolic and hormonal changes during aerobic exercise in distance runners.

A group of long-distance runners is studied in order to clarify aspects concerning neuroendocrine mechanisms regulating organic adaptation to maximum effort, with special interest in the function of the growth hormone in fat metabolism and the possible use of ketone bodies as an alternative source of energy. A test is designed on a treadmill with a gradient of 3% and progressive increases in speed of 2 Km/h every 10 min, starting at 6 Km/h, and continuing until exhaustion. Masks are worn to enable the breath by breath measurement of expired gases and the subjects are monitored electrocardiographically using V5. For blood sample collection an antecubital vein is catheterized with a system enabling the replacement of the blood volume extracted by means of perfusion with physiological saline solution, and the increasing concentration of hormones in the blood is evaluated. The results obtained, indicate that epinephrine as well as GH hormones increase significatively from 20 min of exercise in runners promoting changes from carbohydrates to lipids as fuels to carry out exercise. The concomitant variations in energy substrates support the former hypothesis of work. Moreover, the muscle could employ acetylCoA originating from acetoacetate as an alternative metabolic source of fuel during maximum effort.

Adipose Tissue

[Acute presentation of leukodystrophy due to mitochondrial cytopathology and multiple deletions of mitochondrial DNA].

INTRODUCTION: Deletions of mitochondrial DNA (mtDNA) are a known cause of various mitochondrial cytopathies, which are sporadic and usually not due to maternal transmission. The multiple deletions are usually transmitted on a Mendelian pattern, and are frequently of autosomal dominant character. Leukodystrophy may be part of the picture, or even the form of presentation, of some mitochondrial cytopathies. Thus, in a case of leukoencephaly of unknown origin, mitochondrial cytopathy should be considered in the differential diagnosis. CLINICAL CASE: We present the case of a boy with no previous clinical abnormalities who, at the age of 13, suddenly fell to the floor with an encephalopathy which required aggressive treatment, needing mechanical ventilation and prolonged sedation. Following partial recovery spastic-dystonic quadriplegia remained. Neuroimaging showed advanced leukodystrophy with small hemorrhages in the white matter, which later disappeared. After rejecting other aetiologies, mitochondrial cytopathies in muscle were studied. A partial defect of the I and IV complexes of the respiratory chain and two deletions of mtDNA were shown. CONCLUSIONS: This case is another example of the variable clinical presentation of mitochondrial cytopathies and yet another argument for their inclusion in the diagnosis of leukodystrophy of unknown origin.

Acute Disease

Spontaneous ascent of the testis.

OBJECTIVE: To report confirmed cases of spontaneous testicular ascent in patients with a cryptorchid testis which had been previously placed in the scrotum. PATIENTS AND METHODS: Between 1972 and 1992, 46 cryptorchid testes (36 patients), which were previously verified to be in the scrotum by staff paediatricians or paediatric surgeons, were treated surgically. The clinical, surgical and anatomicopathological records were reviewed to determine testicular position and associated conditions, and biopsies were taken from 35 testes. RESULTS: The mean time between the last "normal' exploration until the testes ascended was 4.5 years. Before ascent, the testes were confirmed to be in the scrotum by up to seven separate recorded examinations. During surgical treatment, an open processus vaginalis was found in 18 testes. The mean (SD) tubular fertility index was 40 (37)%. CONCLUSIONS: This study confirms that a previously descended testis can ascend spontaneously. The clinical and anatomicopathological characteristics of these testes were similar to those of the cryptorchid testis.

Child

Maintenance of the threshold/maximum heart rate quotient in swimmers.

The anaerobic threshold (AT) was calculated in 23 swimmers by field methods: MADER (MM) and modified exponential MADER (EM) and laboratory methods: SKINNER (SM), ROBERGS (RM), CONCONI (CM), and ventilatory (VM). Two types of test were designed. The first in a swimming pool (test 1), performing four series of increasing intensity swims, and the second on a cycle ergometer increasing until exhaustion (test 2). In both tests the heart rate (HR) was recorded in beats per minute by telemetry. Despite the different HR at the AT: 180.0 +/- 2.7 (MM), 179.1 +/- 2.4 (EM), 166.0 +/- 2.9 (SM), 157.0 +/- 2.8 (RM), 167.6 +/- 2.7 (VM) and 168.8 +/- 2.2 (CM), and the different maximum HR (HRmax) in the two tests: 201.6 +/- 2.0 in Test 1 and 188.5 +/- 1.6 in Test 2; the percentage HR in the AT/HRmax proved to be similar for all the methods except RM (88.0%-89.2%). The mechanism of organic control in progressive exercise can therefore have, in this test, a "threshold" zone at a given percentage of the maximum capacity of adaptation, both when the exercise is carried out in a pool and also on a cycle ergometer.

Adaptation, Physiological