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Biomedical subjects

M L Larsen

Publications and source records attributed to M L Larsen.

69 records · Page 4Linked to original sources
PubMed1986

Heparin cofactor II activity in plasma: application of an automated assay method to the study of a normal adult population.

A manual chromogenic substrate method for the determination of heparin cofactor II (HC II) activity in plasma has been adapted to the Cobas Bio centrifugal analyzer. By reducing the dermatan sulfate concentration used, interference by opacity was avoided, and the correlation between the manual and the new automated method was high (r = 0.96). Plasma samples from 182 females and 197 males were examined. The mean values of HC II activities in this normal population was relatively high, with a total range of 43-150% and a standard deviation of 17%. 4 apparently healthy individuals had levels below 60%. In males, the mean HC II activity was higher in the 50-59 yr age group than in either the 20-29 yr group or in the group above 60 yr (p less than 0.05). In females, the postmenopausal age group had higher mean HC II activities, but the difference was not statistically significant.

Adult↗
PubMed1984

Assay of dermatan sulfate cofactor (heparin cofactor II) activity in human plasma.

An assay measuring the thrombin inactivating effect of human plasma in the presence of dermatan sulfate (DS) is described. Test plasma, diluted 1/50, is incubated with human thrombin in the presence of DS. Remaining thrombin is determined with chromogenic substrate 2AcOH . H-D-CHG-Ala-Arg-pNA. Three dilutions of reference plasma suffice and the standard curve is linear. Antithrombin III (AT) exerts a small (3-8%) effect in the assay. When test plasma contains heparin above 0.05 U/ml, this unspecific effect of AT increases, but it may be abolished by antibodies against AT. In a normal material (n = 50), the SD of DS cofactor activity was greater (15%) than that of AT (8.7%). DS cofactor was normal in hereditary AT deficiency and in 15 patients with deep venous thrombosis. In liver cirrhosis and in DIC, both inhibitors were markedly depressed, to similar degrees (r = 0.84).

Antithrombin III Deficiency↗
PubMed1982

Inhibition of activated coagulation factor VII by normal human plasma.

An amidolytic assay system with tissue thromboplastin (Tpl), purified coagulation factors VII and X, and the chromogenic substrate S-2222 was developed. Antithrombin III (AT) accounts for about one third of the total inhibition exerted by normal plasma in this test system. This effect of AT was prevented by adding purified AT blocking antibodies. Normal plasma and serum showed approximately similar inhibitory effects. The inhibition was probably directed against activated factor VII (F VIIa). Gel filtration of adsorbed normal plasma on Ultrogel AcA 34 showed three inhibitory peaks which were different from AT.

Antithrombin III↗
PubMedDate not supplied

Influence of radiographic contrast media on granulocyte enzymes and complement during uncomplicated urographies.

Four different radiographic contrast media (RCM) were used for i.v. urography in 40 patients, none of whom had complications. No rise in C3d was observed for any of the RCM, indicating that complement was not activated. However, significantly decreased values for CH50 were detected when the non-ionic RCM iopamidol and iohexol were used, and this may be due to interaction between the RCM and the complement molecules. Significantly increased numbers of neutrophils were observed in patients receiving ioxaglate, iohexol and diatrizoate, which may be due to inhibition of granulocyte adherence. No rise in the concentration of elastase and lactoferrin was observed. On the other hand, significantly decreased values of elastase were seen after injection of diatrizoate, which may be due to inhibition of the degranulation process by this media.

Complement Activation↗
PubMedDate not supplied

Comparison of overnight, morning and 24-hour urine collections in the assessment of diabetic microalbuminuria.

With the aim of comparing different urine collection periods in the assessment of micro-albuminuria, urinary albumin excretion rates (AERs) were measured in samples from 24 h, overnight, and morning urine collections in 54 patients aged 17 to 62 years with insulin-dependent diabetes mellitus with a mean duration of 15 years. The AER in overnight urine was found to be reduced by 25% compared to the rate in 24 h and morning urine. Assessing the ability to predict a 24 h AER within the microalbuminuric range (20-200 micrograms/min) we found a sensitivity of 90% and a specificity of 88% for both overnight and morning urine samples. These values were slightly improved by relating AER to the excretion of creatinine and it is concluded that overnight as well as morning urine collections can be used when diagnosing microalbuminuria in insulin-dependent diabetics. Furthermore the results show that the albumin to creatinine ratio in morning urine is a reliable estimate of 24 h AER and better than measurement of the albumin concentration alone.

Albuminuria↗
PubMedDate not supplied

Dyslipidemia and coronary artery disease. Prevalence and treatment in patients referred for coronary arteriography.

UNLABELLED: A reduction in serum total cholesterol (T-C) levels has been shown to reduce mortality in patients with coronary artery disease and to decrease the need for revascularization. To examine the prevalence and treatment of lipid disorders in patients referred for their first coronary angiogram, medical history and fasting blood samples were collected in 108 consecutive patients. Ninety-one patients (84.3%) fulfilled the criteria for dyslipidemia. Hypercholesterolemia had previously been demonstrated in 53 patients (49.1%), and 34 (64.2%) of these patients still had T-C > 6.0 mmol/l at the time of admission. Among 55 patients who were unaware of any lipid disorders at admission, 28 (50.9%) had T-C > 6.0 mmol/l. CONCLUSION: The majority of patients referred for their first coronary angiogram and possible revascularization suffered from dyslipidemia. Many patients with previously recognized dyslipidemia were insufficiently treated.

Aged↗