Search PubMed⌕ Search

Biomedical subjects

B Bake

Publications and source records attributed to B Bake.

At least 127 records · Page 7Linked to original sources
PubMed1976

Investigation of the orthostatic reaction after intravenous administration of imipramine, chlorimipramine, and inimpramine-N-oxide.

Three age- and sex-matched groups of 10 patients were treated intravenously with imipramine, chlorimipramine, and imipramine-N-oxide respectively, in increasing doses from 25 mg to 150-175 mg given as single daily infusions during 1 hour. No systemic changes of heart frequency and blood pressure were found during the infusions in spite of the high dosage of tricyclic antidepressants given such a short period as 1 hour. The patients were examined regarding orthostatic reactions as well as ECG changes before, after 4-5 infusions and after 8-10 infusions. There were more orthostatic abnormalities and ECG changes in the patients treated with imipramine than in those treated with imipramine-N-oxide and there were practically no changes in the chlorimipramine group. However, no statistically significant orthostatic changes were found.

Adult↗
PubMed1976

Effect of inspired volume on closing volume.

Closing volume (CV) was ?EASURED WITH THE RESIDENT GAS TECHNIQUE IN 12 HEALTHY SEATED SUBJECTS AGE 22-70 YR, AND IN 8 SUBJECTS WITH THE BOLUS TECHNIQUE. Various volumes were inspired (Vi range: 20-100% vital capacity) from residual volume and CV was assessed on the subsequent recording of expired volume versus gas concentration. The results indicate that the resident gas technique may erroneously underestimate CV at reduced Vi in conformity with calculations which predict that during expiration, after a certain reduced VI, the nitrogen concentration is identical in the most basal lung region and at the mouth. CV obtained with the bolus technique decreased linearly with reduced Vi and the effect appeared to be age dependent according to the equation CV50/CV100=0.0078 X age +1.18, where CV50 and CV100 denote the bolus CV corresponding to Vi=50% and 100% of vital capacity. Therefore, in older subjects, during tidal breathing, airways appear to close at substantially lower lung volume than previously considered.

Adult↗
PubMed1976

Effects of shape changes of the chest wall on distribution of inspired gas.

The configuration of the chest wall was measured with magnetometers applied at various levels of the rib cage and abdomen. Distribution of ventilation was measured in the supine position using a bolus of xenon-133 inspired at a flow rate of 0.1 liter per sec. Measurements were made during spontaneous breathing, during augmented abdominal breathing, after manual lateral compression of the lower part of the rib cage followed by a predominantly abdominal motion, and after similar compression followed only by increase of the lateral basal rib cage diameter. Basal compression gave a decrease in lateral diameter of 5 to 7 per cent. During spontaneous breathing, apical ventilation exceeded basal ventilation. During an inspiration with an increase of the lateral basal rib cage diameter after compression, the ventilation of basal peripheral regions increased somewhat. No other systematic effects of the changes in either chest wall diameter at the start of inspiration or the type of inspiration were found on distribution of inspired boli.

Humans↗
PubMed1976

A simple pressure calibrator.

A simple reliable, easy-to-use, and inexpensive device for obtaining any predetermined static gas pressure within +/- 35 cm H2O is described. It is suitalbe as a calibrator for pressure transducers as used in respiratory physiology. It is more convenient to use than an ordinary U-tube.

Manometry↗
PubMed1975

Effects of abdominal breathing on distribution of ventilation in obstructive lung disease.

1. The regional distribution of ventilation was studied with a 133Xe wash-out technique both after rebreathing and after intravenous injection of the isotope in six patients with chronic obstructive lung disease. Measurements were performed in the sitting position during spontaneous and augmented abdominal breathing respectively. The contribution to ventilation of the rib-cage and abdomen was measured with magnetometer recordings of the respiratory variation in the antero-posterior diameters. 2. The relative contribution of the abdomen to ventilation increased from about 40% during spontaneous breathing to about 67% during augmented abdominal breathing. 3. There was no systematic difference in the ventilation distribution between the two breathing patterns.

Abdomen↗
PubMed1975

Voluntary changes of thoracoabdominal shape and regional lung volumes in humans.

We measured regional lung volumes from apex to base in humans during changes in thoracoabdominal shape which we monitored with magnetometers. In erect subjects, voluntary changes of shape at FRC did not change regional volume distribution. In supine subjects, the effect of negative pressure applied to the abdomen and a similar thoracoabdominal configuration achieved by voluntary means were studied. The distribution of regional volumes in both situations was the same as that measured during relaxation at the same overall lung volumes. We concluded that neither voluntary changes in shape nor negative abdominal pressure influenced the human pleural pressure gradient. This result, which differed from findings in animals, was probably because the human chest was relatively stiff and behaved with one degree of freedom; all parts of the human rib cage changed dimensions proportionally while negative abdominal pressure distorted the rib cage of animals.

Abdomen↗
PubMed1975

Regional distribution of a 133Xe labelled gas volume inspired at constant flow rates.

We measured the regional distribution of 480 ml of 133Xe labelled gases inspired from FRC at constant inspiratory flow rates ranging from 0.1 to 6 litres/s. The gases used were air and 20% O2 in helium. At low inspiratory flow rates the gas was preferentially delivered to the dependent region of the lung. At maximal inspiratory flows, all regions of the lung were more evenly ventilated. The rate of redistribution was found to be slower and more even than in previous studies using smaller volumes of inspired gas. Assuming equal and synchronous changes of pleural surface pressure, these results can be reasonably predicted by the mechanical time constant theory applied to a simple two-compartment lung model based on equal regional resistances. Breathing the HeO2 mixture did not significantly change ventilation distribution at any flow rate.

Functional Residual Capacity↗