Biomedical subjects

J Lindahl

Publications and source records attributed to J Lindahl.

35 records · Page 2Linked to original sources

PubMed1980

Quantification of ineffective erythropoiesis in megaloblastic anaemia by determination of endogenous production of 14CO after administration of glycine-2-14C.

The determination of the early peak of 14CO production that results from haem turnover after administration of glycine-2-14C was studied in patients with pernicious anaemia. The accuracy of this technique in measuring ineffective erythropoiesis was assessed by comparison with other measurements of the severity of the disease. 6 patients were studied before specific treatment and 2 of these also after treatment. The endogenous production of 14 CO was calculated from determinations of the production of CO by a rebreathing technique and of the specific activity of CO washed out from the body CO store by oxygen breathing. The early labelled peak was increased 7-39 times compared to that in healthy control subjects and represented 35-86% of the total production of 14CO as compared to 13% in controls. The early labelled peak was significantly correlated to the Hb concentration, mean red cell volume and endogenous production of CO. 2 patients, twice examined, showed a moderately increased early labelled peak also after specific treatment. This was attributed to persistence of some ineffective erythropoiesis in 1 patient and possibly increased hepatic haem turnover in the other. The magnitude of the early labelled peak and the maximal activity of 14CO found in the samples of CO collected from the body CO store were significantly correlated. In conclusion, with the present method the early peak of 14CO reflected the ineffective erythropoiesis in patients with pernicious anaemia. The early labelled peak could be predicted from the maximal activity of 14CO found in the samples of CO washed out from the body CO store.

Aged↗

PubMed1980

Endogenous carbon monoxide production after bicycle exercise in healthy subjects and in patients with hereditary spherocytosis.

The occurrence of haemolysis after bicycle exercise was studied by determination of, inter alia, the endogenous carbon monoxide production (VCO) before and after 20 min of exercise at a load of about 70% of predicted maximal oxygen uptake. Eight healthy subjects and six patients with hereditary spherocytosis were studied. VCO was 14.4 and 10.5 mumol CO x mmol per total body haeme per day before and after exercise, respectively, in healthy subjects, and 32.6 and 25.4 mumol CO x mmol per total body haeme per day in the patients. The differences were not statistically signficant. No significant changes occurred in serum total bilirubin, lactate dehydrogenase, haptoglobin or serum iron/total iron binding capacity. In conclusion, no increase in the destruction rate of red cells was observed after this type of exercise, neither in healthy subjects nor in patients with hereditary spherocytosis. In addition, a decrease in COHb of about 20% during exercise was observed in both groups. This could be explained by a redistribution of CO from haemoglobin to myoglobin in association with changes in intracellular oxygen tension in working muscles.

Adult↗

PubMed1980

The production of 14CO following the administration of 2-[14C] glycine in normal subjects determined by an oxygen washout technique.

The endogenous production of 14CO during the first week after administration of 2-[14C]glycine, i.e. the early peak of 14CO derived mainly from erythropoietic and hepatic haem turnover, was measured in six normal subjects. Samples from the body CO store were collected by washout of CO with oxygen breathing, CO concentration of expired gas was determined with an infrared CO-meter and, for determination of 14C activity, CO washed out was oxidized to CO2 in a trapping system and absorbed in ethanolamine. The endogenous production of CO was measured with a rebreathing technique and the production of 14CO was calculated. The specific activity and total amount of circulating red cell haemoglobin haem was determined to calculate the potential late peak of 14CO production. The method for determination of 14CO expired was demonstrated to be specific and reproducible and no haemolysis induced by the sampling procedure was detected. The average production of 14CO was 6.94 nCi/24 h the day after injection of 100 muCi of labelled glycine and decreased gradually to 1.08 nCi/24 h on day 8. The early labelled peak was 32.9 +/0 8.1 nCi (mean +/- SD) and the potential late labelled peak 221 +/- 30 nCi. The early peak represented 13.0 +/- 2.9% of the calculated total production of labelled CO, a figure significantly lower than erythropoietic and hepatic haem turnover calculated from total bilirubin or CO production and red cell life span, probably due to the hepatic component being underestimated by the radiolabelled precursor method.

Carbon Monoxide↗

PubMed1977

Hereditary nephronophthisis with a life span of three decades. Light and electron microscopical, immunohistochemical, clinical and family studies.

Familial nephronophthisis was diagnosed in a son and two daughters of a mother who herself died in uraemia at the age of 29 years. The son died at 33 years, two daughters are alive at 30 and 33 years. Our cases suggest a dominant autosomal type of inheritance because the mother married twice; the affected son was from the first marriage and the affected daughters from the second marriage. There was no known consanguinity between the parents. The pathogenesis of the disease can be explained by a slowly progressive process that leads to complete or partial obstruction of the tubules in the corticomedullary area, and also, therefore, to cystic dilatations. Histological evidence for this is provided by the proliferation of fibroblasts around the collecting ducts and other tubules, prominent thickening of the tubular basement membrane, and fibroblasts and collagen fibrils in or inside the thickened basement membranes. An ultrastructural description of affected kidneys is given.

Adult↗

PubMed1977

Immediate changes in blood flow and oxygen metabolism of the cirrhotic liver following portacaval shunt operations.

In 15 patients with cirrhosis of the liver, the pressures in a systemic artery, in the inferior vena cava and the portal vein, flows in the portal vein and the hepatic artery, and oxygen content and acid-base balance in the arterial, portal and hepatic venous blood were studied during operation before and after the construction of an end-to-side portacaval shunt. Portal pressure decreased from 23 to 13 millimeters of mercury. Portal flow increased from 660 mililiters per minute to the liver to 1,300 milliliters per minute through the shunt. Hepatic arterial flow increased from 230 to 480 milliliters per minute, but this did not fully compensate for the loss of portal blood flow to the liver. Accordingly, total hepatic blood flow was reduced. There was also a decrease in the oxygen transport to the liver, but in spite of this, there was no change in the oxygen content in the hepatic vein nor any production of acid metabolites. Possible implications of these findings on the preoperative investigation of patients with portal hypertension are discussed.

Adolescent↗

PubMed1976

Fall in blood pressure during radiation therapy.

Blood pressure and heart rate at rest in the supine and standing positions were followed before, during and after irradiation for malignant tumours in 114 patients. A statistically significant gradual reduction in blood pressure during the treatment period was established. This was more marked in older patients and in patients with higher initial blood pressure but was not related to the region irradiated or the type of tumour treated. Particularly if the patient experiences vertigo and nausea on change of position, it seems advisable to check the blood pressure during treatment.

Adolescent↗

PubMed1976

Effects on the cardiovascular system of irradiation for malignant lymphoma.

In 55 patients irradiated for malignant lymphoma the complaints were recorded as well as ECG, blood pressure, exercise test and heart volume before, during and one and 6 months following treatment. ECG abnormalities and fall in blood pressure occurred during treatment. Reduced physical working capacity was found one month after treatment. After 6 months all parameters had returned to pretreatment levels. Attention should be paid to the considerable reduction in blood pressure that does occur in some cases during treatment.

Adult↗

PubMed1974