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Biomedical subjects

B Christophersen

Publications and source records attributed to B Christophersen.

27 records · Page 2Linked to original sources

The effect of dietary alpha-bromopalmitate on blood lipids in the rat.

When alpha-bromopalmitate was fed to rats for 9-30 days, the level of serum triacylglycerol increased up to 2-fold over the concentration of controls. alpha-Bromopalmitate treatment had no effect on concentration of complex lipids in liver, while the triacylglycerol level in heart was significantly enhanced. From metabolic studies using isolated hepatocytes and liver microsomes, it is suggested that the increased serum triacylglycerol level after alpha-bromopalmitate feeding is mainly due to reduced fatty acid oxidation in both liver and peripheral tissues, and to a lesser extent, to inhibited fatty acid uptake and esterification.

Animals↗

Effect of a low fat diet on essential fatty acid metabolism in healthy human subjects.

The fatty acid pattern in phospholipids of serum and platelets, and conversion of labelled 18:3(n-3) and 20:3(n-6) in cultured lymphocytes was studied in healthy subjects consuming a low fat diet for four weeks. In serum and platelets the level of polyunsaturated C20 and C22 fatty acids was maintained stable, while the content of 18:2(n-6) was significantly decreased. The delta 6-desaturase activity in lymphocytes was increased after the low fat diet, while the rate of delta 5-desaturation was unchanged. It is concluded that the rate of delta 6-desaturation and perhaps also chain-elongation is regulated by the content and composition of dietary lipids in order to maintain the fatty acid pattern of phospholipids stable.

Adult↗

Metabolism of erucic acid in adipocytes isolated from rat epididymal fat.

The metabolism of [14-14C]erucic acid and [U-14C]palmitic acid has been investigated in adipocytes isolated from rat epididymal fat. The rate of acylation of [14C]erucic acid in cellular lipids and oxidation to CO2 and acid-soluble activity was ca. 1/3 of the rate with [14C]palmitic acid as substrate. A maximal incorporation of fatty acids in triacylglycerol was found at a fatty acid concentration of 0.8 mM in the medium, both with [14C]erucic acid and [14C]palmitic acid as substrate. Glucose added to the medium increased the esterification and decreased the oxidation of both fatty acids. No significant chain-shortening of [14C]erucic acid to shorter monoenes was identified in the fat cells. Increasing concentrations of unlabeled palmitic acid in the incubation medium markedly inhibited the esterification of [14C]erucic acid, whereas unlabeled erucic acid had little effect on the rate of esterification of [14C]palmitic acid.

Adipose Tissue↗

Systemic heparinization of uremic patients and its effects on blood lipids and on in vitro toxicity of the plasma.

The effect of heparin on plasma lipids was investigated in uremic patients prior to and during hemodialysis, and in healthy individuals receiving equal heparin doses. The effects of heparin on plasma lipids were correlated with the effects of plasma on phytohemagglutinin (PHA)-stimulated lymphocytes, and on the function of human mononuclear phagocytes cultured in vitro. The plasma concentrations of high density lipoproteins, cholesterol and albumin were not influenced by systemic heparinization or hemodialysis. Plasma triglycerides showed a significant fall in both groups tested, and remained almost unchanged during hemodialysis. The ratio between the molar concentration of free fatty acids and albumin increased in both groups following systemic heparinization and was significantly correlated with a rise in plasma toxicity.

Adult↗

Metrizamide in high-dose urography.

The non-ionic water-soluble contrast medium metrizamide (Amipaque) was used for high-dose urography in 11 patients with apparently normal renal function. Films of good quality were obtained. Adverse reactions and the effect on pulse and blood pressure as well as a large number of blood and urine laboratory parameters were recorded. Only clinically insignificant effects occurred, and the medium is recommended for further use in urography.

Adult↗

Glucose dehydrogenase in beef (Bos taurus) and rainbow trout (Oncorhynchus mykiss) liver: a comparative study.

The monomer molecular mass of glucose dehydrogenase (GDH, EC 1.1.1.47) from rainbow trout liver and beef liver were estimated to be 90 kDa for both enzymes, by electrophoresis in the presence of Na-dodecyl-SO4 (SDS). The 90-kDa proteins were partially degraded to about 60 kDa when purified with a delayed procedure without protease inhibitors. Tryptic cleavage of the 90-kDa proteins gave fragments of about 60 kDa and 30 kDa, being similar for trout and beef GDH. Isoelectric points, kinetic and thermodynamic properties of the two enzymes are markedly different. Triton X-100 stimulated and stabilized the reactions catalysed by the purified enzymes.

Animals↗

Lipoprotein(a), other lipoproteins and hemostatic profiles in patients with ischemic stroke: the relation to cardiogenic embolism.

Lipoprotein and hemostatic profiles including coagulation inhibitors were determined in 136 patients with acute ischemic stroke. Based on clinical examination, cerebral computed tomography, Doppler ultrasonography of precerebral arteries and transthoracic echocardiography, the strokes were classified as cardioembolic (n = 38), non-cardioembolic (n = 92), and mixed cardioembolic/hypertensive (n = 6). Patients with cardioembolic stroke were older than patients with non-cardioembolic stroke. Lipoprotein(a) was higher in the cardioembolic than in the non-cardioembolic group. Lipoprotein(a) was not significantly correlated to the other lipid levels and may represent an independent lipid risk factor. The non-cardioembolic group had higher levels of total cholesterol, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, low-density lipoprotein cholesterol, apolipoprotein A1, and apolipoprotein B. The cardioembolic group had higher concentrations of fibrinogen and D-dimer, and lower levels of antithrombin, protein C, protein S and heparin cofactor 2 than the non-cardioembolic group. The differences in the hemostatic profile are consistent with thrombosis due to activated coagulation being more involved in the pathogenesis of cardioembolic than of non-cardioembolic stroke. Lipoprotein(a) seems to be more associated with coagulation markers of thrombosis than with atherosclerosis, whereas the other lipids mainly seem to be risk factors for atherosclerosis.

Adult↗