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Biomedical subjects

P Bartsch

Publications and source records attributed to P Bartsch.

At least 91 records · Page 5Linked to original sources

Pulmonary regional ventilation. C15O2 single breath method. New technical improvements.

After a single inhalation of C15O2 labelled air, from residual volume to total lung capacity, followed by a few seconds apnea, it is possible to record in four or six lung zones the regional activity changes on a time basis. A first fast rise in activity is seen during the inhalation phase, corresponding to the ventilation in the region of interest (ROI). During the apnea, a slower decreasing component is observed in the different ROI, proportional to the regional blood flow, as almost instantaneously C15O2 is converted to labelled water. After the pioneer work of West & Dollery (1962) very few papers appeared on the subject despite technical improvements as, for instance, coincidence counting of radioactive events. We thus decided to improve the reproducibility and accuracy of the method which were of such a poor quality that no individual measurements were possible in the past. Were of critical importance: a careful positioning of the patients between the counters, a faster electronics improving true coincidence counting. In six healthy volunteers (age 22-35) the values obtained for regional ventilation with the C15O2 single breath were compared to the values given by the inhalation of a poorly soluble gas (Nitrogen13). The correlation between the two sets of measurements is high (r = 0.975). The slope of the regression line is 0.859, ordinate at origin is 2.35. This reveals a systematic error. A mathematical model was therefore developed to take into account the "washout" occurring during the constitution of the ventilation peak, and to correct its value.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The histological structure of Kveim tests parallels the evolution of pulmonary sarcoidosis.

The histopathology of the granulomas induced by Kveim antigen varies in patients with sarcoidosis. Eighty skin sites of Kveim tests were biopsied 4 and 5 weeks after the antigen was injected into the skin of patients with pulmonary sarcoidosis. The histological features in the skin of Kveim tests differed according to the stage of evolution of sarcoidosis and seem to parallel the pathological changes in the lung.

Granuloma↗

Asbestosis and systemic lupus erythematosus.

A case associating asbestosis and clinical lupus erythematosus (SLE), both diagnosed according to standard criteria, is described. It is suggested that such an association may bear some analogy to the well-known 'Caplan-Collinet' syndrome, associating silicosis and rheumatoid arthritis.

Adult↗

[A radioisotope method of measuring pulmonary vascularization].

The study of regional perfusion of the lungs by a radioisotopic method using a multiple detectors system and 133 Xenon as radioactive tracer, seems to us, an interesting tool in the investigation of valvular or congenital cardiopathy. This method can be repeated as much as necessary and is not traumatic. The reproductibility is good. The radiation exposure is minimal as well for the patient as for the physician.

Animals↗

[Effect of repeated serotonin injections on temperature regulation in the rat].

The effect of repeated serotonine injections was investigated in thirty Wistar rats tested under normo-, hypo- und hyperthermic conditions. 7 mul of a 0.5% serotonine solution (5HT) were injected into the third ventricle at 1-hr intervals. Temperature responses such as oxygen consumption and rectal temperature were measured and the heat loss was calculated. Intraventricular serotonine produced cooling in all animals. The central mechanisms of heat production were inhibited and those of heat loss were activated. The serotonine responses were most pronounced in hypothermic rats and least effective in hyperthermic animals.

Animals↗

[Influence of mediopreoptic stimulation on temperature regulation in rats before and after serotonin injection].

The effects of electrical stimulation of the Area praceoptica medialis (APM) and intraventricular serotonine injection were investigated in thirty Wistar rats tested under normo-, hypo- and hyperthermic conditions. Temperature responses such as oxygen consumption and rectal temperature were measured and heat loss was calculated. The effects of the first stimulation before serotonine injection were compared with those of the second one after serotonine application in order to prove the influence of serotonine on temperature responses due to APM stimulation. On the other hand, the influence of stimulation on changes produced by serotonine injection should be shown by the recordings of the second serotonine responses with stimulation effects and by comparison of these with those of the first serotonine responses without stimulation effects. The first APM stimulation depending on the rectal temperature before stimulation resulted in decreasing oxygen consumption in hypothermic rats while increasing that of hyperthermic animals. There was a little decrease of rectal temperature under hyper- and normothermic conditions. while under hypothermic conditions animals showed marked depression. The increase in heat loss, however, was least in hyperthermic rats and most pronounced in hypothermic animals. The second APM stimulation did almost not affect the temperature responses after serotonine application in normothermic rats, while causing supercooling agin under hypothermic conditions and insignificant cooling at hyperthermic environment temperature. Comparison of the first and second stimulation effects revealed statistical significant differences at normo-, hypo- and hyperthermic temperatures. The results are discussed under consideration of the different starting conditions before the first and second stimulation. These findings do not indicate that serotonine would shift the sensibility of mediopraeoptic structures and thus unequivocally modifies stimulation effects.

Animals↗