Biomedical subjects
Publications and source records attributed to W Schlick.
Haemodynamic and respiratory function tests were carried out in a dog submitted to left-sided lung homotransplantation. It was observed that successful immunosuppressive therapy enabled the graft to maintain adequate function for the entire 28-month period of observation.
By intratracheal injection of the protease papain to experimental animals parenchymal changes in the lung can be induced, that resemble human emphysema. Papain (dosage 26 to 112 mg, 1 to 4 injections) was given intratracheally to 8 bastard dogs (weighing from 12.5 to 20 kg) during light general anesthesia. Pulmonary function was assessed in weekly intervals and related to morphologic changes in the lung. Static compliance of the lung and FRC measured during respiratory arrest were increased after papain, bronchial resistance, measured while artifically ventilated at constant pressure was also increased. Changes of static lung compliance and FRC were seen after the first administration of papain, but further increased with time of observation and after multiple doses of papain. Increase of resistance was not found before 5 weeks. At quiet breathing resistance was not increased at all. No significant changes were found of arterial pO2 and pCO2, pH, standard and actual bicarbonate, diffusion capacity for O2, tidal volume, minute ventilation and ventilatory rate. Morphological findings confirmed the changes described by others. Pulmonary function appears to be pathological at a time when morphology still seems to be normal. The question is discussed to what extent the model of experimental emphysema induced by proteolytic enzymes can contribute to the understanding of human pulmonary emphysema. Lung function in the course of experimental emphysema is compared with function in different clinical types of emphysema.
Pulmonary emphysema was induced in 8 bastard dogs by intratracheal instillation of Papain. Development of emphysema was documented by pulmonary function tests. The emphysematous animals underwent single lung homotransplantation. Postoperative bronchospirometric measurements revealed that up to the 6th week after transplantation there is no evidence of serious ventilation perfusion inbalance.
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A device is presented for determination of gas free body volume, by which total body volume as well as lung volume together with intestinal gas can be measured. The measurement is performed under water. The subject to be measured keeps his head in an airfilled cylinder which allows free breathing during the measurement procedure under water. The subject sits on a seat which is connected with a vertical "probe" that is submerged in a water basin. This "body density probe" carries several measuring rods of different diameter on its upper end, which lead to an increase of buoyancy when sinking deeper into the water after additional weights have been put on the device. These rods lead to new equilibrium states which are also dependent on the compressable gas volume attached to the probe. Three equilibrium states with different added weights give a physical definition of gas free body volume, which can be calculated from a number of accurately measurable single items.
A new method was used to measure body density in 125 persons (divided into five groups: lean male and female; extremely obese male and female; moderately obese female). There was no correlation between body weight and total body fat in lean males, but a good correlation in lean females. Fat-free body mass correlated well with body weight in both lean groups. There was good correlation between body weight and total body fat in obese males and females. Relative weight (weight related to Broca index) correlated well with fat percentage in obese males, females, and lean women, but not in lean males. The results suggest that the Broca index of over-weight (percentage over-weight = height in cm minus 100) is a good measure of obesity in females and in extremely over-weight males, but no conclusion can be drawn about the amount of fat tissue in males who are only moderately over-weight or under-weight. In these persons fat-free body mass correlates better with body weight than "obesity tissue".
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A new method for determination of the specific weight of the gas-free human body is presented. Volume measurement is facilitated by extremely precise scales, by means of which a well-defined amount of water which was removed from a "patient container" is weighed. After the test subject has entered the container and is standing up to the neck in water, the container is closed. The combined gas volume consisting of the subject's lung volume, his intestinal gas and the air around his head is measured by lowering the pressure by an exactly-defined amount. This is done by opening a valve at the bottom of the container, which results in the outflow of a certain amount of water, the volume of which corresponds to the volume expansion inside the container. The gas volume prior to expansion can then be calculated by application of the gas laws. The advantages of this measuring device are its relatively small size, the high precision and the fact that the procedure is not unpleasant for the subject, as the head is not submerged under water.
According to plain chest roentgenography correlated to needle biopsies the following grades in the course of rejection after single lungtransplantation could be evaluated. 1) Begin of rejection: perihilar alveolar infiltrate. 2) Increase of the infiltrates (positive Airbronchogram). 3) Almost total consolidation of the graft. 4) Complete consolidation of the graft, mediastinal hernia caused by the own lung.
On 10 persons we performed maximal rectangular-progressive bicycle-test, with measuring of VO2max and maximal work in Watts (Wmax), including the working time at the last step. In 18 other young people, we all together made 29 tests without spirometry. In addition to Wmax, the PWC 170 was figured out, once with two higher ergometer steps and once with two lower steps. We found a high correlation between Wmax and VO2max on the one side and PWC 170 and Wmax on the other. If, for the PWC 170 will be utilized, two steps with heart-rates of greater than 140 on the lower and 160 to 170 on the higher step, the PWC 170 seems to be exactly sufficient for estimating the maximal physical working capacity for routine testing of healthy young people.
The substituted benzylamin-derivative fominoben (PB 89 Noleptan) was intravenously administered to 12 patients with chronic obstructive lung disease in order to determine, whether an analeptic action on respiration, which had been found by others in animal studies and in healthy subjects, can also be demonstrated in patients with COLD. Time ventilation showed no statistically significant change. Respiratory rate was increased for a short time, alveolar ventilation showed a slight but significant increase 35 minutes after i.v. injection of fominoben, however no significant change in the first 10 minutes after injection.--Arterial pO2 was slightly but not significantly increased in the first 10 minutes after fominoben, while the same patients showed a significant decrease of pO2 after injection of placebo. As alveolar ventilation at this time had not significantly changed, the increase in pO2 can only be explained by an improvement of regional ventilation-perfusion ratio by fominoben. -In conclusion it can be stated, that a marked stimulative action on respiration by fominoben could not be demonstrated. There was, however, no depression of respiration as it is associated with most other caugh medications. As the drug has been shown to be an excellent caugh sedative, lack of respiratory depression can be considered as a considerable advantage.
In the present study 12 canine lungs perfused in a BELZER perfusion unit for 17 hours using Albumine solution were homotransplanted. Bronchospirometric evaluation up to the 21st postoperative day have shown sufficient function. There is no remarkable difference in minute ventilation, alveolar ventilation and oxygen uptake when compared with non-stored lung homografts.
Pulmonary function studies after single-lung homotransplantation in dogs with experimentally induced emphysema. Pulmonary emphysema was induced in 8 bastard dogs by intratracheal instillation of papain (dose 2 mg/kg 3 to 5 times in 6 to 10 weeks). Development of emphysema was documented by weekly pulmonary function studies. The emphysematous animals underwent single-lung homotransplantation. Postoperative studies of lung function were performed immediately after transplantation and 1 week postoperatively. Bronchospirometric measurement revealed that ventilatory function and oxygen consumption of the graft was at least equal to the animal's own emphysematous lung. Up to 1 week after transplantation there is no evidence of serious ventilation-perfusion imbalance.
The system AUPREM is a new measurement device, which allows continuous measurement of the mechanical properties of the lung and bronchial system. Pulmonary elastance and airway resistance can be measured continuously even in extremly debilitated or unconscious patients. Transpulmonary pressure change, airflow and tidal volume are used as input. From these values airway resistance and pulmonary elastance are calculated. Comparative measurements in a group of healthy subjects and in a group of patients with pathological resistance and elastance values revealed that there was no significant correlation between the system AUPREM and the commonly used methods bodyplethysmography and elastance measurement by oesophageal balloon. However, the differences are in a low order of magnitude.
Experimental emphysema was induced by multiple intratracheal instillation of Papain in a dose of 2 mg/kg body weight in 4 bastard dogs. Development of emphysema was objectivated by pulmonary function tests. Increase of static lung compliance, decrease of lung elastance, and increase of air-way resistance were observed. In addition arterial pO2 decreased while pCO2 remained constant. Following single lung homotransplantation there was an increase of respiratory rate and minute ventilation, the transpulmonary pressure rose in the first postoperative days, static lung compliance was diminished. Four weeks after transplantation typical functional changes of emphysema could be demonstrated concerning the slope and appearance of the compliance loops. Arterial pO2 however remained within the normal range. This functional behaviour does not support the concept of a ventialtion perfusion imbalance after lung transplantation in emphysema patients. Respiratory insufficiency therefore is probably caused by an alveolar type of rejection.
Unilateral homotransplantation of the lung was performed in ten healthy mongrel dogs. Assessment of pulmonary function was obtained immediately after transplantation ten days and four weeks postoperatively. A conventional endotracheal tube was used for measurement of total lung function. A special tube was deviced for bronchospirometric measurements in dogs. A moderate increase of tidal volume and marked increase of respiratory rate and minute ventilation could be noted immediately after transplantation. Oxygen consumption was not changed significantly. There was a marked decrease in arterial pO2-level following transplantation, which was improved during the follow-up studies and found within normal limits at the tenth postoperative day. Bronchospirometry immediately following transplantation revealed equal ventilation values of both lungs, but oxygen consumption of the transplant was reduced 50% compared to the recipient's own lung. On the tenth postoperative day ventilatory function of the transplant was found close to that of the recipients own lung. Oxygen consumption in respiratory equivalent at this time averaged two thirds of the animal's own lung. Four weeks following transplantation no further significant change of respiratory function could be noted.
Knowledge of the regional ventilation/perfusion ratio is of great interest for the diagnosis and therapy of disorders of pulmonary function. By injecting intravenously a bolus of Xe-133 during breathholding and by recording the influx of activity into the lung with a scintillation camera and analogue tape storage, the regional perfusion of the lungs can be determined, using the count-rate increase per unit time. Once the maximum count-rate is reached the patient is allowed to breathe normally. The slope of the count-rate decrease over the lungs is a measure of ventilation. The regional ventilation/perfusion ratio is calculated by dividing these two indices. Regional disturbances of the ratio are the most frequent cause of hypoxia. The demonstration of such disturbances are therefore of significance in the diagnosis and therapeutic control of pulmonary diseases.