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Biomedical subjects

L Wallin

Publications and source records attributed to L Wallin.

89 records · Page 5Linked to original sources

12-Hour simultaneous registration of acid reflex and peristaltic activity in the oesophagus. A study in normal subjects.

Twelve-hour simultaneous registration of acid gastro-oesophageal reflux and peristaltic activity in the oesophagus was carried out on 30 healthy subjects. The intensity of the acid gastro-oesophageal reflux was determined by automatic integration of the pH variation. Acid gastro-oesophageal reflux to pH less than or equal to 4 occurs in normal subjects within a range of 0--2.4% of the total registration period. The intravariation was measured in 10 investigations on 1 subject, and lay within the intervariation. To maintain the pressure-measuring system intact, 3 ml H2O/h were fed to the proximal and distal pressure catheters, respectively; it has been shown that this small quantity of water has no influence on the pH variation. Peristaltic activity for the entire measuring period was recorded and related to the individual reflex episodes. The total activity was found to be dependent on the level of consciousness, with little activity occurring during sleep. A positive correlation was found between the lowest pH during a reflux episode and the peristaltic activity in the oesophagus (p less than 0.001), between the lowest pH during a reflux episode and the duration of the reflux episode (p less than 0.001), and between the peristaltic activity and the duration of the reflux episode (p less than 0.001). During long-term registration of oesophageal pH it appears that pH less than or equal to 4 is a usable parameter for distinguishing between pathological and non-pathological acid gastro-oesophageal reflux. Sudden falls in pH to below 4 release increased peristalsis in the oesophagus.

Adult↗

Effect of metoclopramide on oesophageal peristalsis and gastro-oesophageal sphincter pressure. A study in normal subjects.

The aim of the present study was to measure the amplitude, the duration, and the velocity of the peristaltic pressure wave in the lower part of the oesophagus in the basal state and at different time intervals after oral intake of 10 and 20 mg metoclopramide. In addition, gastro-oesophageal sphincter pressure was measured in the basal state and 90 min after the intake of metoclopramide. The pressure studies were carried out in eight healthy subjects, using a pressure probe consisting of two open-tip polyethylene catheters that were fed by a capillary tubular system and connected to external pressure transducers. Sphincter pressure was measured (intermittent withdrawal), and the probe was positioned with the distal opening 5 cm orally to the sphincter. Dry and wet (bolus, 5 ml of water) swallows were made in randomized order in the basal state and at the time intervals after the intake of metoclopramide. Finally, the sphincter pressure measurement was repeated. No differences were seen with regard to the peristaltic activity: amplitude, duration, or velocity. Sphincter pressure rose from 12 to 19 mmHg after 10 mg (p less than 0.05) and from 13 to 20 mmHg after 20 mg metoclopramide (p less than 0.05). There were no significant differences between basal values and the response to 10 or 20 mg metoclopramide.

Administration, Oral↗

Haemodynamic effects of oxytocin (syntocinon) and methyl ergometrine (methergin) on the systemic and pulmonary circulations of pregnant anaesthetized women.

The haemodynamic effects of oxytocin (Syntocinon) and methyl ergometrin (Methergin) were studied in 9 healthy females in the first trimester of pregnancy. The patients were anaesthetized with sodium thiomebumal, pethidine and pancuronium bromide and ventilated on a Manley respirator. 10 i.u. oxytocin given as an i.v. bolus brought about a fall in femoral arterial pressure of 40%, systemic resistance 59% and pulmonary resistance 44% 30 sec after injection. However, the heart rate increased 31% and stroke volume 17%, so that the cardiac output increased by 54%. The pulmonary arterial pressure and wedge pressure were increased by 33% and 35%, respectively 150 sec after injection. No changes were seen in the haemodynamic parameters during infusion of 80 mU oxytocin for 10 min. 0.2 mg Methergin brought about an increase in the femoral arterial pressure of 11%, pulmonary arterial pressure 27% and wedge pressure 31%, with no changes in the other measured parameters. The use of oxytocic drugs in patients with compromised circulation is discussed.

Adult↗

Comparative pressure measurements in the oesophagus by means of in situ tip-transducers and external transducer systems.

Basal gastro-oesophageal sphincter pressures and peak peristaltic pressure amplitudes in the oesophageal body 5 and 15 cm proximal to the gastro-oesophageal sphincter were measured with three different set ups in six healthy volunteers. The in situ tip-transducer measurements were compared to two different external pressure transducers in a perfused catheter system and to an external pressure transducer in a non-perfused catheter system. The in situ tip-transducer recorded higher sphincter pressures and peristaltic amplitudes than those recorded by the perfused and non-perfused systems (P less than 0.01). There was no difference between the pressures recorded by perfused systems in conjunction with the different external transducers. The perfused systems recorded sphincter pressures higher than those recorded by the non-perfused systems (P less than 0.02 and P less than 0.01), whereas the non-perfused system recorded higher peristaltic pressure amplitudes than those recorded by the perfused systems (P less 0.01 and P less than 0.01). The importance of the bend of the in situ tip-transducer was shown experimentally. It is concluded that the ideal system for recording oesophageal pressures is a perfused catheter set-up with minimal compliance. The probe with three side holes at the same level ensures registrations of the lowest occlusion pressure at the measuring point.

Adult↗

The effect of HCl infusion in the lower part of the oesophagus on the pharyngo-oesophageal sphincter pressure in normal subjects.

A measuring unit combined with a perfused catheter has been developed for measurement of the pharyngo-oesophageal sphincter pressure. The system is able to register pressure measurements using either intermittent or continuous withdrawal of the catheter, at the same flow rate (0.5 ml/min). Repeated measurements of pharyngo-oesophageal sphincter pressure have been made on eight healthy volunteers. No differences were found in the sphincter pressures measured by the continuous and the intermittent withdrawal techniques (p greater than 0.10); the coefficient of variation was 0.18 for both techniques. The pharyngo-oesophageal sphincter pressure was measured during infusion of 0.1 N HCl (5 ml/min) 5 cm proximally to the gastro-oesophageal sphincter. There was an increase in the pharyngo-oesophageal sphincter pressure after 1 min of infusion (p less than 0.05). Measurements after 5 min and 10 min were no different from the initial value; thus a fall was observed between the first and the fifth minute (p less than 0.05). The observed rise in sphincter pressure may be explained as a response acting to prevent gastro-oesophageal reflux from entering the pharynx.

Adult↗

Prolactin response to electroconvulsive therapy.

Prolactin response to electroconvulsive therapy (E.C.T.)was investigated in nine patients with endogenous depression. Four patients undergoing minor gynaecological surgery who had had the same type of intravenous anaesthesia as the E.C.T. group were studied as controls. 15 minutes after E.C.T. there was a 10 to 50 fold increase in serum-prolactin in eight of the patients. The effects of anaesthesia and surgery on serum-prolactin in the controls were negligible.

Adult↗

The YY syndrome.

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Adolescent↗