Biomedical subjects
Publications and source records attributed to V Smejkal.
The authors demonstrate on the case of a 21-year-old female diabetic (type I), who had been well compensated with insulin for five years, the life threatening procedure of a popular healer. By eliminating insulin he induced severe keto acidotic coma.
The aim of the study was to ascertain the reasons which lead to discontinuance of exercise on the bicycle ergometer in healthy untrained subjects and to assess the dependence of dyspnea on breathing pattern and on ventilation. The physical load was progressively increased to the maximum in 11 volunteers at the age of 21 +/- 1 years. During exercise some cardiovascular and respiratory parameters were measured simultaneously with the degree of dyspnea. Breathlessness was rated by means of a scaling according Borg, where 0 indicates no, 10 maximal dyspnea. Dyspnea was not a reason for termination of maximal exercise, its value being 6 +/- 1.9 in men and 4.5 +/- 2.3 in women at the end of exercise. The reasons for termination of exercise were the sensations of general fatigue and pain in lower the extremities. The degree of dyspnea correlated with the minute ventilation, with the decrease of end-tidal CO2 concentration, with the duration of exercise and some other values. The grading varied among subjects. The mathematical dependence of dyspnea was summarised by two regression equations, one without suppression, the other with suppression of interindividual differences in responses.
The object of the investigation was to assess the influence of previously experienced maximal dyspnoea on assessed values of dyspnoea in healthy volunteers. In these subjects threshold to medium dyspnoea was evoked by application of three different flow resistances of 1 or 2 or 4 kPa-1.s-1 for a period of 2 mins. Maximum dyspnoea was evoked by occlusion of the airways for a period of several breathes. The control and experimental group comprised a total of 16 healthy volunteers aged 21 to 22 years. To evaluate the dyspnoea the 10-point Borg visual analogue scale was used. It was revealed that the magnitude of different resistances in blind and random inclusion of these resistances was reliably differentiated by the subjects regardless whether they had a previous experience of maximal dyspnoea. A significantly higher grade of dyspnoea was, however, recorded in all three tested resistances in subjects who had a previous experience of dyspnoea. This phenomenon is explained by the sensation of anxiety and threatened vital function closely before the model obstruction in the experimental group. The authors recommend based on their own experience and data in the literature Borg's ventical scale for quantification of dyspnoea. When assessment are made it must be, however, stated how the examined subjects were instructed in advance and whether they had a previous experience of dyspnoea.
We tested the effect of a fixed breathing frequency on the partial pressure of CO2 in the end-tidal air (PETCO2) in resting healthy subjects. In the first experiment, three different rates of breathing were dictated: the same frequency of breathing as the subject's control one (1f), a double frequency (2f), and half of the control frequency (0.5f). 10 min dictate of 1f and 2f induced a decrease of PETCO2. The dictate of 0.5f had no significant effect on PETCO2. In the second experiment, 1f was dictated for 30 min, inducing a decrease of PETCO2 throughout the duration of the dictate. These results demonstrate that fixing the breathing frequency by the dictate affects the chemostatic control of ventilation.
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There are considerable differences in the reactivity of tracheobronchial muscles to bronchoconstricting substances in guinea pigs and rats. The aim of the present investigation was to assess whether these functional differences have a morphological or biochemical background. Therefore specimens of this tissue were taken for histological and biochemical examination i. e. assessment of cyclic nucleotides. While in the nucleotide content no interspecific differences were found, there were some morphological differences which may explain the less marked response of smooth muscles of the rat to bronchoconstricting stimuli.
The aim of our investigation was to assess whether a preinserted model resistance of a certain magnitude will expand the airways during inspiration and thus reduce the resistance of the airways conceived as the sum of the value of the endogenous airway resistance without obstruction and the value of the exogenous pre-inserted model resistance. The model resistance and resistance of the airways were assessed by means of a whole-body plethysmograph. The airway resistance was evaluated in 10 healthy men during inspiration and expiration, using a dictated breathing pattern. When a model resistance of 0.75 kPa.l-1.s-1 was preinserted during dictated minute ventilation of 30 l.min-1 and an air current of 1 l.s-1 the value of the airway resistance increased markedly, as compared with the same breathing pattern without obstruction. The resistance increment was, however, by 30% lower than the expected value. At the same time the functional residual lung capacity increased.
The authors studied the question of the completeness of ventilation of an additional dead space in the form of a tube 3 cm in diameter and with a volume of 600 ml. Seven young volunteers were examined while breathing with and without the tube, seated at rest and during a two-grade exercise load on a bicycle ergometer. The criterion of ventilation of the tube was enlargement of the dead space by 600 ml during breathing through the tube. The functional dead space was always calculated from the tidal volume and the CO2 concentration in mixed expired air and in an end-tidal sample, using the Bohr equation. In every case, the tube was found to be completely ventilated by breathing, both under resting conditions and during exercise. In breathing during the bicycle exercise, the ratio of the functional dead space to tidal volume fell from 0.3 to 0.19 and a similar decrease was recorded in breathing through the tube.
Well-trained divers can be expected to differ from healthy controls in their ventilatory response to breathing through a tube and to physical exercise. Therefore, we measured their minute ventilation (VE) at rest and during breathing through a tube combined with two levels of physical exercise (1 or 2 W.kg body weight-1). For breathing through a tube an additional dead space of 600 ml was used. All divers were trained in the breath-hold technique and in the use of the breathing apparatus. Their mean period of training as divers was 9 +/- 6 years. The approximate age of the subjects was 25 years. The pattern of breathing and the oxygen uptake were measured by spirometer, the end-tidal concentration of CO2 was measured and all experiments were carried out above sea level. The ventilation of the divers at rest was comparable to that of the controls. During physical exercise it was smaller whether during breathing through a tube or not. The inadequate increase of VE during exercise in divers was associated with hypercapnia only at a higher physical work intensity (of 2 W.kg-1). This finding is interpreted as a lower chemoregulatory response to the combined stimuli of hypercapnia, hypoxia and physical exercise. In some situations significant bradypnoea and higher tidal volumes were found in the divers.
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Eighteen cases of patients with malignant lymphoma of the thyroid are analyzed. Patients were treated by irradiation and/or chemotherapy and in 9 cases the operation of the thyroid was realized. Two patients of operated group and two patients of non-operated group died after 1-365 days due to malignant lymphoma. The mean follow up of living patients is 66.8 months. In 5 cases, the coincidence of malignant lymphoma and lymphocytic thyroiditis was proved. The diagnosis of malignant lymphoma of the thyroid in all cases but one was based on cytology gained from fine needle biopsy and then confirmed in most cases by histology. We advise to use fine needle biopsy as a simple and safe method in all solitary nodules of the thyroid of uncertain origin and urgent fine needle biopsy in cases of fast growing mass on the neck. Fine needle biopsy reliably differentiates between primary thyroid carcinoma, anaplastic carcinoma and malignant lymphoma of the thyroid. Difficulties can arise in differential diagnosis between malignant lymphoma and lymphocytic thyroiditis.
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