Cholesterol metabolism in hypertriglyceridaemia and the effects of treatment.

The faecal output of bile acids and endogenous neutral steroids was increased in three hypertriglyceridaemic patients. One patient had familail type IIb, one had type IV and the third had type V hyperlipoproteinaemia. The hyperlipidaemia in the type IV and type V patients was associated with diabetes and a high alcohol intake. The plasma cholesterol and triglyceride concentrations and the faecal output of bile acids decreased significantly when the type IIb patient was given D-thyroxine plus propranolol, and when the type IV and type V patients were treated by withdrawal of alcohol, a low=carbohydrate diet and insulin or glibenclamide. The findings are discussed in relation to the possibility that hypertriglyceridaemia and increased bile acid synthesis in these patients have a common metabolic origin.     

The sulphite precipitation method for fibrinogen measurement; its use on small samples in the presence of fibrinogen degradation products.

A technique based on precipitation by sodium sulphite (Na2SO3) has been developed for measuring the fibrinogen concentration of small (100 mul) samples. This technique offers technical advantages over the thrombin-clotting method, especially when measuring dilute solutions. Measurements made with the sulphite technique on fibrinogen solutions on plasma samples were not significantly different from those obtained with the thrombin-clotting method.     

Pain-induced alterations in the individual non-esterified fatty acids in serum.

Changes of individual non-esterified fatty acids in serum were studied in 7 metabolically healthy patients, suffering from idiopathic trigeminal neuralgia, who underwent electrocoagulation of gasserian ganglion under neurolepthypalgesia. The mean concentration of fatty acids increased by about 40% during the strong surgical pain stimulus. The increased lipolysis affected all individual fatty acids in proportion to the ratio of their presence in adipose tissue. The mechanism of pain-induced activation of lipase and possible consequences of alterations in individual non-esterified fatty acids are discussed.     

Congestive cardiomyopathy and the selenium content of serum

A deficiency of selenium is suspected to be involved in the pathogenesis of congestive cardiomyopathy. Therefore the serum selenium content of 20 patients with proven congestive cardiomyopathy was measured and compared to that of a healthy control group. The serum selenium content of the patients with cardiomyopathy was found to be different from that of the healthy control group. The mean value of selenium in serum for the control group was 80.1 μg Se/l (SD ± 13.2) within a range of 53 and 117 μg Se/l. From the 20 patients with congestive cardiomyopathy six patients showed selenium concentrations in the normal value range of the control group; in the serum of 14 patients a distinct lower selenium content was found (mean value 47.8 μg Se/l (SD ± 16.2)) within a range of 23 and 70 μg Se/l. A positive correlation was found between serum selenium content and the left ventricular ejection fraction. Our results suggest that a deficiency of selenium may be present in a number of patients with congestive cardiomyopathy.     

The measurement of human erythrocyte carbonic anhydrase I by the enzyme linked immunosorbent assay (ELISA)

A method is described for the assay of human erythrocyte (RBC) carbonic anhydrase I (HCAI) by the enzyme linked immunosorbent assay. The method was found to be a simple, reliable and precise technique and gave a mean C.V. for 40 samples, assayed in quadruplicate, of 3.32% and a range of 0.84-5.9. The mean erythrocyte HCAI value and standard deviation for 20 normal men and women were respectively 16.9 +/- 3.4 and 15.4 +/- 2.1 mg HCAI/g haemoglobin. The use of heparin as an anticoagulant interfered with the assay resulting in apparent HCAI concentrations as low as 60% of those obtained using EDTA.     

A simplified method for purification of the creatine kinase isoenzyme of human brain (BB)

A greatly simplified procedure has been developed for purification in high yields of creatine kinase isoenzyme BB from human brain. The procedure consists of fractional precipitation with ethanol, adsorption chromatography on hydroxylapatite, and fractional precipitation with ammonium sulfate. The essentially homogeneous enzyme obtained may be used as the antigen for radio immunoassay of blood isoenzyme MB of creatine kinase, which specifically increases following myocardial infarction.     

Causalgia: Redefinition as a clinical pain syndrome

In this report, the following criteria were used for the diagnosis of causalgia: (a) the presence of continuous, burning pain distal to a site of injury; (b) hyperalgesia and allodynia in the painful area; and (c) a traumatic event occurring proximal to the painful area and within weeks prior to the onset of pain. The McGill pain questionnaire was used to test the selected pain population for homogeneity. The scores were similar among the patients and different from the scores in other pain syndromes. It is concluded that the above criteria are sufficient to make the diagnosis of causalgia. In addition, it appears that a central nervous system abnormality best accounts for the clinical features of causalgia.     

Determination of amniotic fluid palmitic acid concentration for the estimation of fetal lung maturity

Palmitic acid concentrations in amniotic fluid (AF) were determined in 135 patients with normal and pathological pregnancies between the 27th and 42nd week of gestation. There was a sharp rise in the mean palmitic acid concentration after the 34th weeks of gestation from 2.7 μg/ml to 9.9 μg/ml at term. This increase is almost identical with the rise of AF-lecithin. It was found that between 70% and 100% of AF-palmitic acid originates from lecithin. 65 patients were delivered within 24 h after amniotic fluid sampling. 7 infants of these patients developed a respiratory distress syndrome (RDS). In all cases with RDS AF-palmitic acid concentration was far below 5 μg/ml. Assuming an AF-palmitic acid concentration > 5 μg/ml for characterising fetal lung maturity (= no RDS), there were no false negative results, but 16% false positive results. However, the determination of AF-palmitic acid concentration seems to be a most reliable method for the assessment of fetal lung maturity.     

Urinary excretion of 3 -methylxanthine and related compounds in children

When screening urine of psychomotorically retarded children by 2-dimensional paper chromatography we found large amounts of an unknown product. After isolation this compound was identified as 3-methylxanthine by using multiple-analytical techniques. Ultraviolet spectra and the major mass spectra peaks are reported for the identified compound and also for 1-methylxanthine. The latter substance also occurs in urine, especially at older age. Another urinary compound is 7-methylxanthine. Evidence is presented that 3-methylxanthine and 7-methylxanthine are metabolites from theophylline and theobromine, occurring in stimulants such as tea and chocolate; 1-methylxanthine probably originates from coffee.Some quantitative data concerning high excretory levels of 3-methylxanthine and 1-methylxanthine are given.     

Plasma cholesterol esterification in hypertriglyceridaemia

Plasma cholesterol esterification was assessed in hypertriglyceridaemic patients and normal subjects by two in vitro methods, one using autologous substrate and one using exogenous substrate. There was a significant negative correlation between cholesterol esterification rate and the plasma triglyceride concentration when this was assessed with autologous substrate or with substrate from a hypertriglyceridaemic donor. The percentage of esterified cholesterol in plasma and the esterification rate were always reduced when the plasma triglyceride concentration exceeded 7 mmol/l and the rate of esterification rose significantly with appropriate triglyceride-lowering therapy in such patients. Evidence is presented that the impaired cholesterol esterification observed in severe hypertriglyceridaemia is secondary to a reduced concentration of substrate high density lipoprotein cholesterol, as well as to an excess of large triglyceride-rich lipoproteins.     

Determination of noradrenaline and adrenaline in plasma by a radioenzymatic assay using high pressure liquid chromatography for the separation of the radiochemical products.

Plasma catecholamines are determined by a radioenzymatic assay using high pressure liquid chromatography for the separation of the labelled radiochemical products. Noradrenaline and adrenaline are converted to their O-methylated analogues, normethanephrine and metanephrine, by the enzyme catechol O-methyltransferase in the presence of tritiated S-adenosyl-L-methionine. Non-radioactive carriers are added, whereupon the metanephrines are extracted in an organic phase and re-extracted in an aqueous phase. The aqueous phase is dried, the residue taken up in a phosphate solution and chromatographed. The normetanephrine and metanephrine peaks are collected, converted to vanillin and assayed for radioactivity. The detection limit for noradrenaline is 32 ng/l plasma and for adrenaline 16 ng/l plasma. Intra- and interassay variables are respectively 6.2 and 10% for noradrenaline and 5.3 and 8.8% for adrenaline. The mean supine levels of noradrenaline and adrenaline in normal subjects are 355 and 61 ng/l plasma, respectively. This highly specific procedure takes two days for one person to assay 45 blood samples and can be reduced to one day if the chromatography step is automated.