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Biomedical subjects

T Strandell

Publications and source records attributed to T Strandell.

At least 19 recordsLinked to original sources

Studies on kidney function in subjects exposed to organic solvents. IV. Effect on 51-Cr-EDTA clearance.

Glomerular filtration rate (GFR) was studied by measuring the 51-Cr-EDTA clearance with single bolus injection technique in 107 men exposed to styrene, toluene or toluene and xylene in their professions and in 48 non-exposed male controls. The clearance values of the controls were significantly related both to body surface area (BSA) and age. These relations were used to calculate expected clearances for the exposed subjects. The clearances of the exposed subjects were on an average 3.8% higher than expected, according to BSA and age in this group. This divergence was not significant. Thus, no reduction in GFR was found in the subjects exposed to organic solvents.

Adult

The effect of fluid deprivation, antidiuretic hormone and forced fluid intake on 51-Cr-EDTA clearance.

The effect of fluid deprivation, antidiuretic hormone (DDAVP) and forced fluid intake on glomerular filtration rate (GFR) was studied in 41 healthy males by determining 51-Cr-EDTA clearance after a single bolus injection. GFR was the same on forced and on free fluid intake. A small, clinically insignificant decrease in GFR (-6.5%), compared to values on free fluid intake, was registered during the periods of fluid deprivation plus DDAVP. There seem to be no objections to combining a clearance study with a concentrating ability test when screening groups of subjects with normal or near normal GFR.

Adult

Hepatic gluconeogenesis during halothane anaesthesia in man.

It is known that hepatic gluconeogenesis from lactate and aminoacids is inhibited by halothane in in vitro studies on isolated, perfused livers. In the present work, the effect of halothane anaesthesia on hepatic gluconeogenesis was studied in three volunteers during a constant amino-acid infusion and compared with three control subjects who did not receive any halothane during the amino-acid infusion. Prior to the investigation, all the subjects were on a carbohydrate-poor diet in order to deplete hepatic glucogen stores. During the investigation, hepatic gluconeogenesis was stimulated by a constant amino-acid infusion which caused a slight rise in total hepatic blood flow (THBF), a marked increase in splanchnic oxygen consumption and oxygen extraction, elevation in blood glucose and urea levels and in splanchnic glucose and urea releases. Halothane anaesthesia administered during continued amino-acid infusion caused a reduction in THBF to sub-control values, while the increased oxygen consumption was only slightly reduced, thereby further increasing splanchnic oxygen extraction. Blood glucose and urea levels of the anaesthetized subjects were consistent with those of the control subjects. Splanchnic release of glucose was reduced almost to control values during halothane. However, the release of urea was only slightly reduced. It is concluded that the stimulating effect on hepatic gluconeogenesis caused by the amino-acid infusion was inhibited during halothane anaesthesia, while metabolization of the amino-acids, other than through gluconeogenesis, proceeded without any major changes.

Adult

On stability of scintillation detectors.

This paper describes how a photomultiplier tube in a scintillation detector changes pulse height with time, when the detector is exposed to a gamma-emitting source and high dynode voltage. The change in pulse height causes a "drift" of the spectral peaks out of the preadjusted energy window, and errors in counting rate of about 20% are detected. The drift is dependent on the photon flux, the level of the high voltage, and the energy of the source. The effect was not present in all detectors studied. It is thus important to check the stability properties of a detector before use.

Gamma Rays

A new device for continuous measurement of gas exchange during artificial ventilation.

A new apparatus, which uses a fuel cell for measuring O2 concentration and calculates O2 consumption (VO2), has been developed for use on the Servo Ventilator. Together with an IR CO2 Analyzer, this equipment also provides CO2 production, end-tidal CO2 concentration, and the respiratory quotient.l The accuracy of this equipment was evaluated by comparison with results from two standard methods: the Scholander technique in combination with a dry gas meter, and mass spectrometry combined with a wet gas meter. The results show that the differences between the VO2 calculated from this equipment and two other standard methods are less than 5%. Thus, the accuracy of the new equipment seems reliable enough to make it a valuable tool in clinical use.

Adult

Capillary permeability in healthy males with different insulin response to glucose.

The capillary permeability in human skeletal muscle, expressed as capillary diffusion capacity (CDC) for 51Cr-EDTA, was determined during exercise with a local clearance method in two groups of healthy male subjects: a younger group with a mean age of 30 years and an older one with a mean age of 58 years. The main finding was that, in both age groups, CDC was significantly negatively correlated to the early phase of insulin response to an intravenous glucose load. No correlation was found between CDC and peripheral insulin sensitivity. CDC was significantly higher in the older age group (P less than 0.01) independent of insulin response, blood flow and body weight. These data indicate that subjects with low insulin response to glucose have a higher capillary permeability than high responders, and that muscle capillary permeability increases with age.

Adult

Bacterial endocarditis. II. A prospective study with clinical, laboratory and therapeutic observations.

In a prospective study 31 cases of proved and 10 of highly suspected bacterial endocarditis were analysed. Valve incompetence was the usual consequence but stenosis occurred in 3 cases, all fatal. Congestive heart failure developed in two-thirds. Secondary manifestations were common and as often caused by alpha-streptococci as by other bacteria. Initial antibiotic treatment was mainly applied according to a fixed schedule, generally with continuous intravenous infusion, followed by oral therapy. In 10 patients, the infection was still active after 6 weeks of therapy. Therefore, we now use intermittent injections or infusions for at least 4--6 weeks. Within a year, 9 patients died from uncontrolled infection together with congestive heart failure, and 1 from heart failure and active chronic endocarditis. In 4, myocardial abscesses or inflammations were found. All 10 had underlying factors or advanced stages of the disease. Of 18 patients with alpha-streptococci or enterococci none died from endocarditis, as against 10 of 23 with other or unknown bacteria. Follow-up yielded valuable information on one-third of the patients. The mortality during the initial hospital stay was 22%, after 1 year 24% and after 5 years 39%.

Adolescent

Bacterial endocarditis. I. A prospective study of etiology, underlying factors and foci of infection.

In a prospective clinical and bacteriological study of 192 consecutive patients with septicemia admitted during the period 1967--1971 to a hospital for infectious diseases, 31 cases of proved (group I) and 10 with probably (group II) bacterial endocarditis were observed and analysed with regard to a variety of factors. The incidence of bacterial endocarditis was 3 per 1 000 admissions. The mean age of the patients was 52.6 years; there was no sex predominance. In about one third of the patients apparently normal valves were involved. Underlying non-cardiac factors were present in two thirds, even in younger age groups, in which chronic alcoholism and intravenous drug abuse were frequent. Secondary manifestations from various organs were noted in about three quarters of the patients, in one quarter already on admission. alpha-Hemolytic streptococci and staphylococci were most commonly isolated, followed by gram-negative enteric rods, beta-hemolytic streptococci, enterococci, and pneumococci. A probable portal of entry could be assumed in 80% of the patients and could often be related to the type of bacteria involved. In some cases, diagnostic or therapeutic procedures preceded the disease. A subacute course of the endocarditis was observed in one third of the patients and all these had alpha-hemolytic streptococci or enterococci. The aortic and mitral valves were equally often involved and equally often infected by alpha-hemolytic streptococci. In 4 patients, 3 of whom were drug addicts, the tricuspid valve was probably involved; all were infected by staphylococci. In one case autopsy revealed a mural endocarditis.

Adolescent

Effect of vasopressin on the mixing of portal venous blood in awake man.

Transumbilical portal venous catheterization was performed in 11 patients for diagnostic selective portography. By use of a multiple-catheter technique, the effects of intravenous infusion of [8-lysine]vasopressin on portal venous mixing of tributary flows was measured by simultaneous blood sampling from the left and right portal branch, taking advantage of the oxygen saturation difference between splenic and superior mesenteric venous blood and also by infusion of 133Xe into one of the portal tributaries. Slight signs of incomplete portal mixing were observed at rest in eight of nine patients. During vasopressin infusion, the heterogeneity of oxygen saturation and xenon activity in the portal branches increased significantly. There was also a significant average shift of splenic venous blood toward the left portal branch with, in some patients, only splenic blood in this branch. Streamlining thus was a dynamic phenomenon related to the reduced and altered portal venous flow pattern. This must be considered during flow measurements, and might also have pathophysiological significance in liver diseases.

Adult

Effect of vasopressin on regional splanchnic blood flows in conscious man.

In 11 conscious normovolaemic patients with acute or chronic pancreatitis the effect of a continuous intravenous infusion of lysine-8-vasopressin, 5 IU/70 kg b.w./20 min on the portal and the hepatic venous blood flows was studied by using multiple portal catheters, oxygen saturation measurements and an indicator dilution technique with continuous infusion of 133Xe into the portal vein or its tributaries. During vasopressin infusion the total hepatic blood flow, estimated by the Bradley technique with indocyanine green dye, was reduced to 61% of the value at rest. Owing to the simultaneously occurring streamlining of the portal venous flow with incomplete mixing of indicator and blood, the portal and hepatic venous blood flows could be measured in only 3 of 9 patients. The reduction in the portal venous blood flow during vasopressin infusion was more marked than the decrease of the total hepatic flow, corresponding to a calculated increase of the hepatic arterial flow of 50%. Total splanchnic oxygen uptake and extrahepatic splanchnic oxygen uptake were unchanged during and after infusion of vasopressin. Thus, changes in splandhnic blood flow could be estimated from changes in arteriovenous oxygen differences. Also by this method a more pronounced reduction in the portal venous than of the hepatic venous blood flow was observed. The decrease during vasopressin infusion of the superior mesenteric venous flow was more marked than that of the splenic vein. The splanchnic circulatory changes may be different for other doses of vasopressin and in cirrhotic patients with higher hepatic arterial blood flow fractions.

Acute Disease