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Biomedical subjects

E Knapp

Publications and source records attributed to E Knapp.

At least 19 recordsLinked to original sources

Proinflammatory cytokines in cardiac myxomas.

Serum levels of various cytokines were measured in three patients with cardiac myxomas presenting with and without constitutional symptoms, immunological features and elevated plasma levels of interleukin-6. Interleukin-6 but not other cytokines (interleukin-1, tumour necrosis factor-alpha, interferon-gamma) relate to immunological features of the patients. Circulating levels of atrial natriuretic peptide correspond to haemodynamic changes but not to the tumour-bearing state itself.

Atrial Natriuretic Factor

Relation of triglyceride metabolism and coronary artery disease. Studies in the postprandial state.

The status of fasting triglycerides as a risk factor for coronary artery disease (CAD) has been considered weak because in multivariate analyses, triglycerides tend to be eliminated by high density lipoprotein (HDL) cholesterol. To further evaluate the role of triglycerides in CAD, we employed postprandial lipemia as a more informative means of characterizing triglyceride metabolism. In 61 male subjects with severe CAD and 40 control subjects without CAD as verified by angiography, we measured cholesterol; triglycerides; HDL cholesterol; HDL2 cholesterol; and apolipoproteins A-I, A-II, and B in fasting plasma and triglycerides before and 2, 4, 6, and 8 hours after a standardized test meal. Both the maximal triglyceride increase and the magnitude of postprandial lipemia (area under the triglyceride curve over 8 hours after the meal) were higher in cases than in control subjects. Single postprandial triglyceride levels 6 and 8 hours after the meal were highly discriminatory (p < 0.001), and by logistic-regression analysis displayed an accuracy of 68% in predicting the presence or absence of CAD. In this respect, accuracy was higher than that of HDL2 cholesterol (64%) and equal to that of apolipoprotein B (68%), the most discriminatory fasting parameter. Multivariate logistic-regression analysis was performed to reduce the number of risk factors to those that were statistically independent. This statistical procedure selected postprandial but not fasting triglycerides into the most accurate multivariate model, which also contained the accepted risk factors HDL2 cholesterol, apolipoprotein B, and age. This model classified 82% of subjects correctly. We conclude that triglycerides are independent predictors of CAD in multivariate analyses including HDL cholesterol, provided that a challenge test of triglyceride metabolism such as postprandial lipemia is used. The study suggests that the metabolism of triglycerides is a critical determinant of cholesterol metabolic routing. The findings support the concept that the negative association between HDL cholesterol levels and CAD actually originates in part from a positive relation between CAD and plasma triglycerides, as ascertained in the postprandial state.

Adult

[An idiopathic floating left-ventricular thrombus].

Four weeks after appendicectomy a 28-year-old man developed dragging pains in the left calf. Left popliteal, posterior tibial and dorsalis pedis arteries could not be palpated. Angiography revealed an embolic occlusion of the left superior femoral artery at the level of the adductor canal. Echocardiography demonstrated a pedunculated left ventricular thrombus, 3.5 x 2.0 cm, as a possible source of the embolus. After successful trifurcation embolectomy and saphenous vein patch-plasty acenocoumarol, 4 mg/d and heparin, 3 x 7500 IU/d were administered. Because the thrombus failed to shrink, systemic thrombolysis, initially 750,000 IU streptokinase and 3000 IU heparin i.v., was begun. After five days the thrombus diameter had decreased to 0.7 cm. But because thrombus movement had increased, streptokinase was replaced by 70 IU/d ancrod i.v. The thrombus completely disappeared within two weeks. The patient was symptom-free during the period of anticoagulation with acenocoumarol. Six months later echocardiography confirmed the absence of thrombus in the left ventricle.

Acenocoumarol

Predictive value of computed tomographic determination of the patency rate of aortocoronary venous bypasses in relation to angiographic results.

From 1978 to 1988, 300 patients with 616 aortocoronary venous bypasses underwent computed tomography (CT) 3 months after surgery, and angiography 1 day after CT. Both angiographic patency rate and CT patency rate were 75%. The sensitivity of the CT test for the detection of patent bypass grafts was 90 +/- 1.4%, the specificity of the CT test for the detection of occluded bypass grafts 72 +/- 3.6%. The observed predictive value of a patent CT test resulted in angiographically patent bypasses in 91 +/- 1.3%; the observed predictive value of an occluded CT test resulted in angiographically occluded bypasses in 71 +/- 3.6%. The low specificity for detecting occluded grafts is a considerable limitation of the technique. The pre-post-test patency ratio curve shows better predictive values for the CT test when there is a low pre-test likelihood of patency than when this is high. Patients with a high pre-test likelihood of occlusion, but who actually have patent coronary artery bypasses are most likely to benefit from this non-invasive test.

Angiography

[Mitochondria number as a prognostic parameter in dilated cardiomyopathy. A long-term follow-up study].

According to morphological criteria of the myocardium, patients with clinical and hemodynamic signs of dilated cardiomyopathy were divided into three groups. Group I: patients with 1-2 mitochondria per 2 sarcomeres (n = 46); Group II: patients with more than 2 mitochondria per 2 sarcomeres (n = 47); Group III: patients with histological findings of myocarditis in the past (n = 33). Mean follow-up in groups I, II, III was 29, 22, 26 months, respectively (6-58, 3-52, 3-62/median 29, 18, 22). Clinical parameters were evaluated at the beginning and at the end of the prospective observation and were classified clinically as "improved, unchanged, deteriorated"; "heart transplantation", "death of cardial causes", "death of other than cardial causes" or "lost to follow up" were the other endpoints of the observation. At the beginning there were no hemodynamic differences between groups I, II, III, except significant difference in ejection fraction and mean ventricular shortening velocity between groups I and II. Scored together with the clinical symptoms "deterioration" and "death of cardial causes" as endpoints, survival rates without event up to 5 years in group I were 83 +/- 7% compared with group II 33 +/- 13% and group III 86 +/- 8%. There were significant differences (p less than 0.01). We conclude that the increased number of mitochondria per 2 sarcomeres in biopsy specimen of patients with dilated cardiomyopathy can be a significant parameter of deteriorated prognosis.

Adult

[Changes in the catecholamine plasma level 3 months after aortocoronary bypass operation].

Plasma catecholamine levels were obtained during diagnostic heart catheterization from the pulmonary artery and aorta and, similarly, renin levels were determined in the pulmonary artery in 31 patients with coronary heart disease and 18 normal controls. 3 months after aorto-coronary bypass surgery the patients with coronary heart disease underwent repeat heart catheterization and the epinephrine, norepinephrine and renin levels were compared with those obtained before operation. Norepinephrine decreased in the aorta from (means +/- SEM) 475 +/- 57 pg/ml to 360 +/- 38 pg/ml (p less than 0.001) postoperatively (controls 225 +/- 21 pg/ml). Epinephrine decreased from 121 +/- 11 pg/ml to 108 +/- 16 pg/ml (p less than 0.001) postoperatively (controls 84 +/- 9 pg/ml). This shows that postoperative relief from myocardial ischemia is associated with normalization of the preoperatively elevated plasma catecholamine levels).

Adult

[Quantitative computed tomographic flow measurements in aortocoronary venous bypass. I. Analysis of variance studies].

In 36 patients, 3 months after aortocoronary venous bypass (ACVB) surgery to the anterior interventricular branch of the left coronary artery, the density-time curve was assessed in the aorta and the ramus interventricularis anterior ACVB by computed tomography (CT). Mean values for area of time-density curve (1539 HU x sec.), effective width (10.9 sec.), peak CM concentration (140 HU), maximum increase of density (71 HU/sec.) and maximum decrease (53 HU/sec.) showed a significant (p greater than 0.01) difference between the results in aorta and the anterior interventricular branch ACVB for all parameters, excepting the effective width. We conclude that assessment of time density-curve parameters in the ramus interventricularis anterior ACVB is feasible; however, the results are significantly different from those obtained in the aorta. Clinical relevance of these data will be established in a second part of the study.

Adult

[Quantitative computed tomographic flow measurements of aortocoronary venous bypass grafts. II. Correlation with angiographic measurements].

In 26 patients with 35 aortocoronary venous bypass grafts (ACVB) quantitative invasive angiographic parameters were compared with flow parameters of contrast medium, assessed by computed tomography. Out of seven different CT-parameters, the maximum decrease of concentration of contrast medium (40 +/- 5 HE/sec; mean +/- SEM) showed a correlation with the angiographic parameter of contrast medium quantitative flow rate (7.2 +/- 0.5 cm/sec) and this correlation (r = 0.536/SEE = 23.17) is significant (p less than 0.001). We conclude that for the single patient assessment of quantitative flow in ACVB by CT with a 3-second repetition rate could be performed with limited accuracy.

Angiography

Risk factors for coronary artery disease: a study comparing hypercholesterolaemia and hypertriglyceridaemia in angiographically characterized patients.

Fifty-two male patients undergoing coronary angiography were allocated to four groups each consisting of 13 subjects: group I had normal coronary arteries and patients in groups II-IV exhibited coronary artery disease. In group II, plasma cholesterol was below 250 mg dl-1 and triglycerides below 160 mg dl-1; in group III, cholesterol was above 270 mg dl-1 and triglycerides under 160 mg dl-1; and in group IV, cholesterol was under 270 mg dl-1 and triglycerides above 180 mg dl-1. The hypertriglyceridaemic group IV had the highest coronary score. In addition, it had lowest lipoprotein lipase activity, lowest HDL-cholesterol and lowest high-density lipoproteins-2 (HDL-2) levels, suggesting that this type of hypertriglyceridaemia is caused--at least in part--by lipoprotein lipase deficiency with impaired removal of the triglyceride-rich lipoproteins and increased catabolism of HDL-2. Our findings point towards a type of hypertriglyceridaemia strongly associated with coronary artery disease which should therefore be treated accordingly.

Adult

[Sweet lupine (Lupinus luteus, var. Aurea/Weico and Lupinus albus, var. Multolupa) proteins. I. Extraction and filtration by Sephadex].

Samples of Lupinus luteus, var. Aurea/Weico and Lupinus albus var. Multolupa flours were analyzed. The flour proteins were extracted and fractionated by gel filtration, and the per cent pattern for both globulins and albumins was then determined. The dehulled seeds, previously analyzed for composition, were ground, defatted and consecutively extracted with distilled water (pH 5.0) and phosphate buffer (0.05 M, pH 8.5). The extracted protein content was measured by the Lowry simplified method. Globulins (pH 8.5 fraction) from both species were filtered through Sephadex G-100; besides, Lupinus albus globulins were filtered through Sephadex G-150, and absorbance of the collected fractions was measured at 280 nm. The dehulled seed (DS) of L. luteus and L. albus revealed a good protein content (58.2 and 41.0%, respectively). The protein extracted from L. luteus was constituted by 17% albumins and 58.4% globulins. In contrast, L. albus presented a higher albumin content (55.6%) than globulins (31.5%). The elution pattern for the Sephadex G-200 gel filtration showed for both lupine species analyzed a preponderant peak I corresponding in L. luteus to 55.0% and in L. albus to 84.1% of the total globulins content. From these results, it may be concluded that the dehulled seed protein content is 42.0% higher for the L. luteus sample than for the L. albus. The applied methodology indicated a predominant content of globulins above albumins in L. luteus, while in the case of L. albus, the albumin content was the highest.

Albumins

[Sweet lupine (Lupinus luteus, var. Aurea/Weico and Lupinus albus, var. Multolupa) proteins. II. Separation by electrophoresis].

The albumins and globulins extracted from Lupinus luteus var. Aurea/Weico and Lupinus albus var. Multolupa defatted flour samples were analyzed by polyacrilamide gel electrophoresis. The purpose was to determine the percentage distribution of pattern in the electrophoretograms and the relative mobility values of protein. The L. luteus albumins densitogram showed six fractions, two of them, No. 2 and No. 4, represented 58.1% of the total. On the other hand, the globulins densitogram revealed five fractions, numbers 1, 2 and 3 representing 90.7%. The densitogram of peak I from Sephadex G-100 globulins filtration indicated two fractions similar to those number 1 and 2 of the total globulins, showing low relative mobility values (from 0.26 to 0.39). The L. albus albumins resolved in four fractions, with No. 2 being the most prevalent (54.3%). In regard to the L. albus globulins, these showed five fractions identical in distribution with those of peak I, fraction 2 appearing as the most important (48.2%). It was found that Sephadex G-100 did not perform a good separation. As to the relative mobility values of globulins, fractions 2 and 3 were the most prominent (relative mobility of 0.35 and 0.48, respectively). It may be concluded that L. luteus albumins presented more components but with lower relative mobility values than those of L. albus. As for the globulins from both lupine flour samples, the gel separated fractions were classified in two groups of components, those of high and of low relative mobility.

Albumins

Increase in Hb-O2-affinity at moderate altitude (2000 m) in patients on maintenance hemodialysis.

Oxygen transport by erythrocytes was studied in eight patients on maintenance hemodialysis before, during and after a 2-week stay at an altitude of 2000 m. Dialysis was continued at that altitude. In all tests, blood samples were collected one or two days following hemodialysis. Pre-altitude tests: The patients exhibited anemia (hemoglobin concentration, Hb = 97.4 +/- 17 g/l). Due to an elevated red cell 2,3-diphosphoglycerate concentration (2,3-DPG) and mild metabolic acidosis, elevated standard and in vivo P50 values (pO2 at 50% oxygen saturation of hemoglobin, sO2) were measured. Altitude: Upon ascent, arterial pO2 decreased from 82 +/- 4 torr to about 60 torr, sO2 was lowered by 5%. After 2 weeks sojourn, pO2 and sO2 increased towards normal values. In contrast to healthy subjects, dialysis patients developed respiratory alkalosis (blood pH: +0.074) upon ascent. This caused a significant shift to the left of the oxygen dissociation curve (ODC), indicated by lowered in vivo P50-values (P50,vv,-2 torr). Red cell 2,3-DPG, P50,st (P50 at a blood pH = 7.4 and pCO2 = 40 torr), hemoglobin concentration and hematocrit showed a high day-to-day variability and did not change because of the altitude exposure. We interpret the increase of the oxygen affinity of hemoglobin in patients with renal anemia as beneficial, as it favors oxygen loading of hemoglobin in the lung during exposure to a hypoxic environment.

2,3-Diphosphoglycerate

Exercise performance of hemodialysis patients during short-term and prolonged exposure to altitude.

The work capacity of patients on maintenance hemodialysis is impaired even at normal inspiratory oxygen pressure. A further restriction can be expected when these patients are exposed to hypoxia at altitude, since most of the usual compensatory mechanisms required to adjust to this environment are impaired or even missing. We tested the tolerance of hemodialysis patients to hypoxia and measured work capacity, hematological, and cardiovascular parameters at rest and during incremental bicycle ergometry during 3-hour exposure to altitudes of 2,000 m and 3,000 m, and during 2 weeks of exposure to an altitude of 2,000 m and compared these data with prealtitude values or with data evaluated in a control group, respectively. In control tests the patients reached work loads at exercise termination of about 66% of age and sex-matched healthy controls, the reduction correlated well with the degree of anemia. During short-term altitude exposure to 2,000 m peak work performance remained unchanged in comparison to prealtitude tests, whereas at 3,000 m it was reduced by about 12%. During the 2-week stay at 2,000 m peak work loads increased significantly by 17% accompanied by an increase in peak oxygen uptake (+15%), blood lactate, heart rates (+10 min-1), and systolic blood pressure (+20 mmHg), whereas the diastolic pressure was comparable to prealtitude values. In another group of hemodialysis patients studied at low altitude under similar experimental conditions none of these parameters was changed. Our data show that during acute exposure to altitudes up to 2,000 m maximal work of hemodialysis patients is not reduced, but is restricted at altitudes higher than that.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization

Functional cardiac assessment before and after left ventricular anterior aneurysm repair, especially as related to work capacity.

Clinical, angiographic and hemodynamic parameters were assessed preoperatively and 12-20 weeks (mean +/- SD: 14 +/- 2) after left ventricular anterior aneurysmectomy in 31 consecutive patients. In 18 patients, associated coronary artery bypass surgery was necessary (1.4 grafts/patient). One patient with mitral valve insufficiency postoperatively required mitral valve replacement. No other complications and no deaths arose. The working capacity of the patients, as measured by bicycle exercise testing, compared a stage of exercise that the patient reached to the expected level of exercise for a normal person of the same sex, age and body surface. Expressed as percent of normals it increased from 39.3 +/- 28.9% (mean +/- SD) to 60.8 +/- 15.5% (p less than 0.001), angina-pectoris-free working capacity increased from 52.6 +/- 41.4 to 89.2 +/- 33.2 W (p less than 0.001). Left ventricular end-diastolic volume was determined by simultaneous biplane angiography and decreased from 277.1 +/- 84.7 to 191.0 +/- 49.1 ml (p less than 0.001). Ejection fraction increased from 35.4 +/- 12.4 to 41.0 +/- 9.6% (p less than 0.05). Left ventricular end-diastolic pressure after angiography decreased from 24.6 +/- 9.2 to 21.1 +/- 11.3 mm Hg (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Plasma catecholamine level in diagnostic heart catheterization studies].

Plasma catecholamine levels were obtained during diagnostic heart catheterization from pulmonary artery and aorta before and after injection of contrast medium in 31 patients with coronary heart disease and in 18 normals. The most striking difference between both groups is a significant decline of norepinephrine concentration in aortas after injection of contrast medium in the normals (from 296 +/- 24 [mean +/- SEM] to 225 +/- 21 pg/ml [p less than 0.01]) and no change in patients with coronary heart disease. The cause seems to be rather increased elimination than a decrease of secretion of norepinephrine. Adrenalin shows only partially similar results. Further studies will have to show, what could be the reason for these different reactions of catecholamine level in normals and in patients with coronary heart disease.

Adult

[Decrease in left ventricular stroke performance following bypass of a significant main coronary artery stenoses].

Hemodynamic parameters and left ventricular function were assessed 14 +/- 4 (means +/- SEM) days preoperatively and 101 +/- 5 days after aortocoronary bypass surgery in eight men (51-65 years of age) with left main coronary stenosis (greater than or equal to 75%). Working capacity on bicycle exercise stress test increased from 43 +/- 7 to 68 +/- 7% of age-, and body-surface matched normals; at the same time cardiac output (thermodilution) decreased from 5.7 +/- 0.5 to 4.7 +/- 2 l/min (p less than 0.05), stroke volume decreased from 78 +/- 6 to 63 +/- 3 ml (p less than 0.01), stroke work from 1.16 +/- 0.10 to 0.89 +/- 0.07 Joule (p less than 0.001), and stroke power from 4.0 +/- 0.3 to 3.4 +/- 0.2 Joule/s (p less than 0.01) postoperatively. Left ventricular volumes decreased postoperatively but not significantly, ejection fraction remained unchanged (57 +/- 13/59 +/- 13%). A control group (PTCA of LAD) showed no significant changes of these parameters. As all patients had a good postoperative result, decrease of stroke work after aortocoronary bypass surgery is not necessarily an expression of postoperative deterioration, since it can coincide with good left ventricular function, angiographically successful revascularization, and an increase in working capacity.

Adult

[Clinical, hemodynamic and morphologic findings in dilated cardiomyopathy].

45 patients (39 men, six women), mean 41 (19-63) years of age with clinical, angiographic and morphologic diagnosis of dilated cardiomyopathy were evaluated in respect of three morphologic classes. Two groups of patients without signs of previous myocarditis were formed, with one-to-two mitochondria per two sarcomeres (group Ia, n = 19), or with more than two mitochondria per two sarcomeres, respectively (group Ib, n = 14); and one group with signs of previous myocarditis (group II, n = 12). The mean relative mitochondrial volume fraction in relation to myofibril volume fraction was significantly lower in group Ia (33 +/- 4/67 +/- 4%) compared to group Ib (39 +/- 5/61 +/- 5%) (p less than 0.01). Mean values of group II (36 +/- 6/64 +/- 6%) were in between the two other groups. Left ventricular enddiastolic pressure (18 +/- 11, 18 +/- 8, 16 +/- 10 mm Hg), pulmonary vascular resistance (473 +/- 414, 406 +/- 205, 458 +/- 495 dyn x s x cm-5), ejection fraction (36 +/- 21, 32 +/- 16, 28 +/- 16%), endsystolic volume index (131 +/- 82, 127 +/- 66, 132 +/- 60 ml/m2), enddiastolic volume index (187 +/- 81, 176 +/- 62, 181 +/- 63 ml/m2), dp/dt max (1951 +/- 875, 1737 +/- 575, 1741 +/- 478 mmHg x s-1) and mean VCF (0.76 +/- 0.58, 0.44 +/- 0.32, 0.54 +/- 0.39 s-1) showed no significant differences between the three groups. Follow-up of the patients in the three groups to median 19, 22, 24 months, respectively, after biopsy, showed an improvement of the clinical findings, especially concerning the groups with one-to-two mitochondria only and with signs of previous myocarditis, but no difference in survival within the three groups. For the individual case our morphologic parameters seem to be without predictive value.

Adult