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Biomedical subjects

U Abildgaard

Publications and source records attributed to U Abildgaard.

At least 145 records · Page 8Linked to original sources
PubMed1985

Heparin assays and bleeding complications in treatment of deep venous thrombosis with particular reference to retroperitoneal bleeding.

Bleeding complications occurred in 30 (11%) out of 280 patients who received continuous heparin infusion for deep venous thrombosis (DVT). 22 (8%) had minor while 8 patients (3%) had major bleeding complications (1 intrathoracic [fatal], 2 gastrointestinal and 5 retroperitoneal). Heparin activity, in daily drawn blood samples, was determined by four assays (chromogenic substrate [CS] assay, activated partial thromboplastin time [APTT], thrombin time with citrated plasma [CiTT] and thrombin time with recalcified plasma [CaTT]). The differences in median heparin activity between patients with minor bleeding and patients with no bleeding did not reach significance for any of the tests. In patients with major bleeding, the differences were significant with the CS (p = .011) and the CaTT (p = .030) assays. Patients with retroperitoneal bleeding had significantly increased median activity judged by all four assays: CS (p = .002), CaTT (p = .003), APTT (p = .010), CiTT (p = .029). The difference was most pronounced after four days of heparin treatment, but there was a considerable overlap with patients without bleeding.

Adult↗
PubMed1985

Bed rest and increased diuretic treatment in chronic congestive heart failure.

To elucidate the effect of bed rest used as an adjunct to increased diuretic treatment, twelve patients with chronic congestive heart failure (CHF) had a 50% increase in loop diuretic dosage and were allocated to either continuous bed rest or bed rest during nights only. The 24-hour bed rest group reduced their weight significantly (mean +/- SEM: 2.00 +/- 0.79 kg, P less than 0.001), whereas the night bed rest group had no significant weight reduction (1.10 +/- 0.37 kg, 0.1 less than P less than 0.2) during three days of observation. Furthermore, the 24-hour bed rest group had a significantly increased diuresis (P less than 0.05) during the first day of the study and a tendency towards increased natriuresis. The cumulated diuresis for the two groups (24-hour bed rest versus night bed rest) during the three days of study were 7773 +/- 700 ml and 5861 +/- 909 ml (0.05 less than P less than 0.1), respectively. Plasma concentrations of adrenaline, noradrenaline, renin and aldosterone were increased, as measured in the supine position. No significant differences were found between the two groups. Plasma concentrations of antidiuretic hormone were within normal limits. In conclusion, continuous bed rest is a reasonable adjunct to diuretic treatment in patients with CHF.

Adult↗
PubMed1985

Changes in plasma antithrombin (heparin cofactor activity) during intravenous heparin therapy: observations in 198 patients with deep venous thrombosis.

Plasma antithrombin (AT) measured as heparin cofactor activity decreased 0.16 +/- 0.13 U/ml (mean +/- SD) in 198 patients who received heparin infusion during 1 wk for deep venous thrombosis (DVT). The decrease was weakly, but significantly correlated to heparin dose (r = 0.15, p = 0.02) and to heparin plasma concentration (r = 0.12, p = 0.05). In patients with subnormal AT at start of heparin treatment, AT decreased less and tended to normalize at the end of heparin infusion, suggesting increased synthetic rate. The decrease in AT was apparently unrelated to the extension or the fate of the thrombus, and also unrelated to other patient and disease characteristics apart from a significantly higher decrease in diabetics. 5 out of 9 patients with AT values below 0.60 U/ml had serious disease, and 1 died from pulmonary embolism (PE) shortly after cessation of heparin (AT 0.22 U/ml). We conclude that the main decrease in AT occurs during the initial 3 d of heparin treatment. If AT stays above 0.70 U/ml after 3 d of treatment, further AT monitoring is hardly indicated.

Adult↗
PubMed1985

Sympathetic reflex-induced vasoconstriction during renal venous stasis elicited from the capsule in the dog kidney.

The study was performed in order to determine the effect of venous pressure elevation induced by unilateral partial renal venous ligation upon total renal blood flow and filtration fraction in the dog kidney. An anaesthesia with no known inhibitory effect on sympathetically mediated vasoconstriction was used. During control conditions instantaneous increase in renal venous pressure to 60 mmHg induced a decrease in renal blood flow (66 +/- 4%) corresponding to an ipsilateral vasoconstriction which was completely abolished following (1) surgical denervation of the kidney, (2) local alpha-receptor blockade of the kidney, and (3) application of lidocaine on the kidney surface. The most striking feature during step increase in renal venous pressure to 40 mmHg was an increase in renal vascular conductance. Renal venous pressure elevation of more than 40 mmHg induced a vasoconstriction, but the vasoconstrictor response was less pronounced as compared with that observed during instantaneous increase in renal venous pressure to the same level. The results strongly suggest that venous stasis of more than 40 mmHg activates an adrenergic sympathetic vasoconstrictor reflex comprising the spinal cord. The reflex is probably elicited from stretch receptors located in the renal capsule. Changes in filtration fraction at venous stasis during the experimental conditions indicate that renal venous pressure elevation activates mechanisms other than neural ones accounting for the reduction in the filtration fraction.

Adrenergic alpha-Antagonists↗
PubMed1985

Psychological and physical long-term effects of torture. A follow-up examination of 22 Greek persons exposed to torture 1967-1974.

After an observation period of about 10 years a follow-up examination was made of 22 Greeks earlier exposed to torture. All had physical symptoms and about 90% of the examinees had chronic psychological symptoms which had appeared after the torture experience, the most notable of which were emotional instability, depression, passivity, fatigue and disturbed sleep. Eight of the victims had a chronic organic psychosyndrome as defined by us. The clinical picture of the torture victims is very similar to other stress-conditioned syndromes, which underlines the significance of the psychological trauma for the pathogenesis. Certain physical symptoms can be related to specific forms of torture; in this series particularly, symptoms of the feet and lower extremities can be related to 'falanga' (repeated blows to the soles of the feet). The most noticeable objective finding was unilateral atrophy of testis in 2 of the examinees caused in all probability by genital torture. Treatment of the sequelae to torture should be initiated as early as possible in the course of the illness, and studies on the effect of this treatment should be carried out.

Adult↗
PubMed1984

Assay of unfractionated and LMW heparin with chromogenic substrates: twin methods with factor Xa and thrombin.

Utilizing two newly synthesized chromogenic substrates (CS), two different assay methods for heparin in plasma have been developed. The assay with bovine factor Xa and the highly reactive "Substrate FXa-1" (CH3 OCO-D-CHA-Gly-Arg-pNA X AcOH) measures both unfractionated (UF) heparin and low molecular weight (LMW) heparin within a single standard curve in the 0.05-1.5 U/ml plasma range. The very similar (and less expensive) assay with bovine thrombin and "Substrate Th-1" (2AcOH X H-D-CHG-Ala-Arg-pNA), measures UF heparin, but not LMW heparin. The standard curves are highly reproducible (CV 3.5-4.7%). For clinical work, a linear standard curve is obtained with three standards and lin-log plot. The "within run" SD was 0.007-0.026 U/ml. Mean recovery of 0.5 U/ml heparin added to 10 pathological plasma samples ranged 0.46-0.53 U/ml (SD 0.034-0.040). Activities of three UF heparin and three LMW heparin preparations are reported.

Animals↗
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↗
PubMed1984

Distribution of myocardial blood flow and capillary diffusion capacity across the canine heart wall.

Myocardial capillary permeability was determined in 20 dogs by applying a new method which resembles the tissue-uptake technique. The method consisted of a bolus injection of 51Cr-EDTA into the left atrium, determination of the average arterial tracer concentration and subsequent assay of myocardial tissue activity 10, 20 and 30 s after injection. Under the fundamental assumption of no back-diffusion of tracer to capillary blood, uptake of 51Cr-EDTA into myocardium allowed calculation of the transfer constant, Kin, independent of blood flow. Regional plasma flow, fpl, was simultaneously determined from tissue content and average arterial concentration of radioactive microspheres and haematocrit. From estimates of Kin and fpl the fractional extraction, E, of 51Cr-EDTA was calculated as E = Kin/fpl. The capillary permeability-surface area product, PS, was calculated as PS = -fpl X k X 1n (1 - E). Constant fractional extraction of 51Cr-EDTA indicates that the method can be employed 10 to 20 s after injection without risk of back-diffusion. From tissue samples taken from subendocardial and subepicardial layers of the left and right ventricular walls and from left and right side parts of the septal region we measured similar PS values. Letting capillary surface area, S, equal 500 cm2 X -1 the permeability coefficient for 51Cr-EDTA was 1.39 X 10(-5) cm X s-1.

Animals↗
PubMed1984

The antithrombotic effect of heparin in deep venous thrombosis: relation to four heparin assays.

In a prospective study, 280 patients with phlebographically proven deep venous thrombosis received intravenous heparin infusion; 224 of the patients were subjected to control phlebography after 5-8 days of treatment. Females above 70 years showed least phlebographic improvement despite similar heparin dosage and heparin activity. Heparin activity in daily drawn blood samples was determined by four different assays. Chromogenic substrate (CS) assay (Coatest heparin), activated partial thromboplastin time (Cephotest), and thrombin time with recalcified plasma (CaTT) showed weak but significant correlations with thrombus resolution judged by phlebography (p = 0.004, 0.003 and 0.018, respectively). A linear prediction equation showed that the phlebographic result was about equally influenced by the mean dose and by the result of any of the three heparin assays. Thrombin time with citrated plasma showed no correlation. CS assay and CaTT showed significantly lower mean heparin activity in patients with (n = 13) than without clinically diagnosed pulmonary embolism (p = 0.012 and 0.001, respectively).

Aged↗
PubMed1984

On the clinical significance of acquired antithrombin deficiency.

The concentration of antithrombin III (AT) was determined with a chromogenic method in plasma samples from 1,302 patients referred for evaluation of the haemostatic system. A clearly subnormal AT level (below 60%) was found in 129 patients. In ten cases, this was explained by known (8 cases) or suspected (2 newborns) hereditary deficiency. Only in 5% of the 600 cases referred with definite or suspected thrombosis, AT was below 60%. These cases had a lethality of about 20%. In about 30% of the cases with liver disease, AT was below 60%. In a group of 72 patients with either severe infection, cardiac insufficiency, malignancy or suspected DIC for other reasons, AT was below 60%. Also in this group lethality was about 50% despite lack of a clear DIC blood profile in 67 of the 72 patients. The results indicate that an AT value below 60% of normal, unexplained by hereditary deficiency, carries a grave prognosis.

Adult↗