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Biomedical subjects

J Dyerberg

Publications and source records attributed to J Dyerberg.

At least 145 records · Page 8Linked to original sources
PubMed1980

Marine docosenoic acid isomer distribution in the plasma of Greenland Eskimos.

The natural docosenoic acid in the human diet can be predominantly 22:1 omega 9 if of plant (generally rapeseed oil) origin, or predominantly 22:1 omega 11 if of marine origin. The fatty fatty acids of dietary fats (meals) and plasma lipids of some Greenland eskimos were examined by open-tubular gas-liquid chromatography. The dietary docosenoic acid isomer distribution pattern showed 22:1 omega 11 to be about 5 times 22:1 omega 9, a ratio typical of marine mammal fats. A similar ratio was also found in the plasma fatty acids, but with a slightly higher proportion of 22:1 omega 9. When correlated with the excellent cardiovascular health of Greenland eskimos, the docosenoic acid data suggest that current concern as to the impact of dietary docosenoic acids on the human myocardium, largely based on animal feeding studies, may be exaggerated.

Animals↗
PubMed1980

Familial functional antithrombin III deficiency.

A family with a tendency to thrombosis and decreased antithrombin III (AT III) activity in plasma, but normal immunoreactive AT III is reported. 7 members of the family had the AT III defect, 4 of whom have had thrombotic episodes. The importance of biological determination of AT III when studying patients with recurrent thrombotic episodes is emphasized.

Adult↗
PubMed1980

Recurrent thrombosis in a patient with factor XII deficiency.

The case history of a patient with moderate factor XII deficiency and recurrent deep vein thrombosis is described. A decreased resting fibrinolytic capacity suggests that 'in vivo' Hageman factor acts mainly as a promotor of clot dissolution. It further indicates that the in vitro demonstration of factor XII as an activator for other biochemical pathways might be of minor importance in vivo, as alternative pathways for activation of these systems exist.

Adult↗
PubMed1980

The effect of arachidonic- and eicosapentaenoic acid on the synthesis of prostacyclin-like material in human umbilical vasculature.

All cis-5,8,11,14,17 eicosapentaenoic acid (EPA) inhibits platelet aggregation. The mechanisms for this inhibition are not known in detail. One of them might be a competitive inhibition of TXA2 production. Even if rat and human vasculature in pure systems covert EPA to PGI3 with the same properties as PGI2, it is essential to known if EPA influences the conversion of arachidonic acid (AA) to PGI2 in human vasculature. This problem was investigated in human umbilical vascular tissue deprived of substrate for PGI synthesis. After incubation with AA or EPA alone and in combinations, prostacyclin synthesis was measured as PGI2. Prostacyclin production in assays with AA and EPA in combinations in the incubation mixture, was found additive as calculated from assays with pure substrates. Thus, EPA did not influence the conversion of AA to PGI2 but gave obviously rise to additional synthesis of PGI-like material.

Arachidonic Acids↗
PubMed1979

Haemostatic function and platelet polyunsaturated fatty acids in Eskimos.

Death from cardiovascular disease is rare among Eskimos. Haemostasis was investigated in twenty-one Greeland Eskimos and twenty-one age and sex matched Danish controls. Platelet lipid analysis demonstrated that a high consumption of omega-3 polyunsaturated fatty acids (such as cis 5, 8, 11, 14, 17-eicosapentaenoic acid [C20:5]) by Eskimos increased the proportion of omega-3 polyunsaturated fatty acids in the platelets. The Eskimos had a significantly longer bleeding-time due to a reduction in platelet aggregation. It is suggested that C20:5 in the platelets is converted by the vascular-wall tissue to an anti-aggregatory prostacyclin. Partial dietary substitution of arachidonic acid by eicosapentaenoic acid may reduce the incidence of thrombotic disorders, including myocardial infarction.

Adult↗
PubMed1979

Lipid metabolism, atherogenesis, and haemostasis in Eskimos: the role of the prostaglandin-3 family.

In Eskimos coronary heart disease is a rarity. This can partly be explained by their favorable plasma lipid levels. An additional factor seems, however, to be that in Eskimo food polyunsaturated fatty acids of the omega-3 series replace those of the omega-6 series. C20:5, omega-3 can be converted by the vessel wall to an antiaggregatory substance, whereas it has no proaggregatory effect on platelets. Consistent with these findings Eskimos were found to have a nearly 2-fold longer bleeding time than Danes. Platelet aggregability, too, was markedly depressed when exposing platelets from Eskimos to ADP and collagen.

Adenosine Diphosphate↗
PubMed1978

Eicosapentaenoic acid and prevention of thrombosis and atherosclerosis?

Unlike arachidonic acid (eicosatetraenoic acid, C20:4omega-6, A.A.), eicosapentaenoic acid (C20:5omega-3, E.P.A.) does not induce platelet aggregation in human platelet-rich plasma (P.R.P.), probably because of the formation of thromboxane A3 (T.X.A3) which does not have platelet aggregating properties. Moreover, E.P.A., like A.A., can be utilised by the vessel wall to make an anti-aggregating substance, probably a delta17-prostacyclin (P.G.I3). This finding suggests that, in vivo, high levels of E.P.A. and low levels of A.A. could lead to an antithrombotic state in which an active P.G.I3 and a non-active T.X.A3 are formed. Eskimos have high levels of E.P.A. and low levels of A.A. and they also have a low incidence of myocardial infarction and a tendency to bleed. It is possible that dietary enrichment with E.P.A. will protect against thrombosis.

Arachidonic Acids↗
PubMed1978

Plasma lipids and lipoproteins in young patients with brain infarction.

Thirty-two patients aged 60 or less with brain infarction were examined with regard to possible changes in lipoprotein pattern as compared with a reference group. Except for a lower concentration of total lipids, cholesterol and high-density lipoproteins in the female patients, no difference was demonstrated in the two groups. In all patients a significant reduction in total lipids, cholesterol, triglyceride and all lipoproteins was demonstrated after the acute cerebrovascular accident presumedly due to the stress situation.

Adult↗
PubMed1978

The absence of factor II in a child with systemic lupus erythematosus.

This report describes a patient with active system lupus erythematosus (SLE), who developed haemorrhagic diathesis due to a lowering of plasma factor II activity. No evidence was found suggesting a plasma inhibitor of factor II. The present case indicates that in some patients with SLE, factor II activity may be low or completely absent due to impairment of factor II synthesis, further that prednisone, but not azathioprine, may ameliorate this defect.

Child↗
PubMed1977

Hyperlipoproteinemia, diabetes, and oxygen affinity of hemoglobin.

Oxyhemoglobin dissociation curves (ODC) were performed on blood from diabetic and nondiabetic subjects with and without hypertriglyceridemia. P50 at in vivo pH was slightly lower than normal in normolipemic diabetics (25.7 versus 26.6 mmHg, p less than 0.05), in spite of increased red cell 2,3-diphosphoglycerate concentration (15.4 versus 14.4 mumole/g Hg, p less than 0.025). P50 at in vivo pH in diabetics with moderately elevated very low density lipoproteins (VLDL)--Type IV hyperlipoproteinemia (HLP)--was likewise found to be slightly lower than normal (25.5 versus 26.6 mmHg, p less than 0.05). In contrast, diabetics with pronounced hyperlipemia due to accumulation of chylomicrons (type I HLP) or due to accumulation of chylomicrons (type I HLP) or due to accumulation of chylomicrons as well as VLDL (type V HLP) showed markedly increased hemoglobin--oxygen affinity (P50:21.1 versus 26.6 mmHg, p less than 0.001). The change in the ODC of normolipemic diabetics is considered to be an expresssion of the presence of an increased proportion of a hemoglobin fraction (Hb Alc) with increased oxygen affinity. The additional change in the ODC of the hyperlipemic patients is thought to be secondary to accumulation of triglyceride-rich particles for the following reasons: (1) a similar increase in oxygen affinity of hemoglobin was demonstrated in familial type I HLP of nondiabetic subjects; (2) normal red cells increased their oxygen affinity when incubated in lactescent plasma; (3) in both acquired types I and V HLP the disappearance of HLP was followed by a normalization of the ODC.

Adolescent↗