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Biomedical subjects

B Puschendorf

Publications and source records attributed to B Puschendorf.

At least 91 records · Page 5Linked to original sources
PubMed1993

Early and rapid diagnosis of perioperative myocardial infarction in aortocoronary bypass surgery by immunoturbidimetric myoglobin measurements.

STUDY OBJECTIVES: To evaluate measurements of myoglobin in the diagnosis of perioperative myocardial tissue damage in aortocoronary bypass surgery. A new immunoturbidimetric myoglobin assay, which yields quantitative concentrations of myoglobin within approximately 1 min, was used. DESIGN: Prospective clinical study. PATIENTS: Thirty-two patients scheduled for elective aortocoronary bypass surgery. MEASUREMENTS AND RESULTS: Myoglobin concentrations in patients without perioperative myocardial infarction (n = 27) increased with aortic unclamping, peaked after 1 h, and decreased to almost baseline values within 4 h. By contrast, myoglobin concentrations in patients with perioperative myocardial infarction (n = 5) further increased after 1 h of aortic unclamping and were significantly higher (p < 0.05) than in patients without myocardial infarction as soon as 3 h after aortic unclamping. In all patients with myocardial infarction, myoglobin concentrations exceeded 400 micrograms/L over a minimum period of 4 h. Ten of 27 patients without perioperative myocardial infarction had episodes of minor perioperative myocardial ischemia (defined as ST-T segment changes in the ECG without a concomitant increase in the activity of creatine kinase isoenzyme MB). Myoglobin concentrations (but not creatine kinase isoenzyme MB activity) were significantly higher in these 10 patients when compared to the 17 completely uneventful cases. CONCLUSIONS: Plasma concentrations of myoglobin are a sensitive marker of perioperative myocardial tissue damage in aortocoronary bypass surgery. Myoglobin measurements with the immunoturbidimetric assay have an important contribution to make to the early and rapid diagnosis of perioperative myocardial infarction.

Aged↗
PubMed1993

Correlation of atrial natriuretic peptide and cyclic guanosine monophosphate plasma concentrations in patients with heart disorders during rest and exercise.

The concentration of atrial natriuretic peptide was measured in order to evaluate its importance in patients suffering from a variety of cardiac diseases. There was a correlation between plasma concentrations of atrial natriuretic peptide and its "second messenger" cyclic guanosine monophosphate (cGMP) in all of the cases examined. We investigated the relationship between atrial natriuretic peptide and cGMP plasma concentrations during rest and exercise in comparison with the scintigraphically assessed left- and right-ventricular ejection fraction in patients with chronic heart disease (n = 20), and after orthotopic heart transplantation (n = 16); plasma concentrations were also measured in healthy controls (n = 14). Atrial natriuretic peptide and cGMP concentrations showed a similar correlation during rest and exercise with r = 0.74 and r = 0.81, respectively. With the exception of patients after heart transplantation, a significant negative correlation was seen between the left ventricular ejection fraction and atrial natriuretic peptide or cGMP plasma concentrations during rest conditions (r = 0.76 or 0.58, respectively). No correlation was apparent between plasma concentrations of atrial natriuretic peptide or cGMP and the left- or right ventricular ejection fraction during exercise. The concentrations of atrial natriuretic peptide and cGMP in plasma differed significantly between healthy controls and patients during rest and exercise. It is noteworthy that atrial natriuretic peptide and cGMP concentrations were markedly higher in patients after heart transplantation than in patients suffering from chronic heart disease. Our results indicate that plasma atrial natriuretic peptide and cGMP concentrations are sensitive markers of cardiac impairment.

Atrial Natriuretic Factor↗
PubMed1993

Granulocyte elastase in acute myocardial infarction.

Plasma concentrations of polymorphonuclear granulocytes elastase (PMN elastase) in complex with alpha-1 proteinase inhibitor are a marker of neutrophil activation. The latter complex, creatine kinase and cardiac troponin T, were measured in peripheral venous blood samples serially drawn in 39 patients with acute myocardial infarction. Of the total, 29 received intravenous thrombolytic therapy either with streptokinase (n = 15), urokinase (n = 7) or recombinant tissue type plasminogen activator (n = 7). Creatine kinase activities and cardiac troponin T concentrations were used as markers of myocardial tissue injury. In all patients with acute myocardial infarction, PMN elastase was elevated (median 80 micrograms/l, interquartile range 71 to 100 micrograms/l). Peak and cumulative (area under curve) concentrations of PMN elastase did not correlate closely with determinants of myocardial injury (r < 0.2, n.s.). PMN elastase increased during the first 6 h after starting thrombolytic therapy, whereas it decreased in conventionally treated patients and 12 h later increased. Maximum concentrations of PMN elastase, however, were not significantly higher in patients with thrombolytic therapy than in those without. In acute myocardial infarction patients with complications such as cardiac arrest with subsequent resuscitation (n = 5), cardiac rupture (n = 1) or cardiogenic shock (n = 2), PMN elastase plasma concentrations were significantly higher (p = 0.04) than in uncomplicated infarctions. In the complicated patients, changes in elastase concentrations paralleled or even preceded changes in the clinical presentation. Therefore, thrombolytic treatment seems not to significantly influence the amount of systemic neutrophil activation, but plasma PMN elastase could be a useful marker to monitor and identify complications in acute myocardial infarction.

Adult↗
PubMed1993

Plasma immunoreactive endothelin in the acute and subacute phases of myocardial infarction in patients undergoing fibrinolysis.

Endothelin is a potent vasoconstrictor of coronary arteries. We measured plasma concentrations of immunoreactive endothelin (irET) in 46 patients with confirmed acute myocardial infarction (AMI). When compared with irET concentrations in healthy individuals who served as controls, irET concentrations in patients were already significantly elevated at the time of admission (P = 0.002) and remained significantly elevated for at least 2 days after AMI (P < 0.01). IrET concentrations peaked 1 h (mean) after admission (8.5 +/- 3.9 ng/L, P = 0.02 compared with values at time of admission). Reperfusion of the infarct-related artery markedly influenced irET release. Before the start of thrombolytic therapy, irET concentration in patients with early reperfusion did not differ significantly from that of those without early reperfusion. However, irET time courses were significantly (P = 0.03 by analysis of variance) different in patients who did and did not have early reperfusion. In the latter, peak irET concentrations correlated closely with the angiographic left ventricular ejection fraction (r = -0.71, P = 0.03), maximum creatine kinase MB mass concentrations (r = 0.69, P = 0.01), and creatine kinase activities (r = 0.59, P = 0.03). Reflow and reversion of myocardial ischemia are associated with a reduced irET release in patients with AMI.

Adult↗
PubMed1992

Alteration in proportions of histone H1 variants during the differentiation of murine erythroleukaemic cells.

We have investigated the changes in the relative amounts of histone H1 zero and all five H1 variants during the differentiation in vitro of Friend erythroleukaemic cells. Three different agents were used as inducers of differentiation: dimethyl sulphoxide, hexamethylenebisacetamide and sodium butyrate. By applying a combination of reverse-phase h.p.l.c. and one-dimensional gel electrophoresis we observed that, during differentiation in vitro, (1) the relative amount of each subtype changes upon induction and that (2) dimethyl sulphoxide and hexamethylenebisacetamide produce a similar histone H1 pattern with a strong increase in histones H1 zero and H1c, a modest increase in histone H1e and a decrease in the relative amounts of histone H1a, H1b and H1d, whereas butyrate induces a different pattern, particularly with respect to both histones H1c and H1e: H1c increased slightly, and H1e strongly, during differentiation. These results are compared with changes in the histone H1 pattern during differentiation in vivo in the mouse [Lennox & Cohen (1983) J. Biol. Chem. 258, 262-268] and in the rat [Pina, Martinez & Suau (1987) Eur. J. Biochem. 164, 71-76], and similarities and deviations are discussed.

Acetamides↗
PubMed1992

Separation of phosphorylated histone H1 variants by high-performance capillary electrophoresis.

High-performance capillary electrophoresis (HPCE) was used to separate successfully distinct phosphorylated derivatives of individual histone H1 variants. With an untreated capillary (50 cm x 75 microns I.D.) the electrophoresis was performed in about 15 min. Inconvenient interactions of these highly basic proteins with the capillary wall were eliminated by using 0.1 M sodium phosphate buffer (pH 2.0) containing 0.03% hydroxypropylmethylcellulose. Under these experimental conditions the histone H1 variants H1b and H1c obtained from mitotic enriched NIH 3T3 fibroblasts and isolated by reversed-phase high-performance liquid chromatography were clearly separated in their non-phosphorylated and different phosphorylated forms. This result was confirmed by acid-urea gel electrophoresis, comparison with non-phosphorylated histones H1b and H1c, isolated from quiescent NIH 3T3 cells, and incubation of multi-phosphorylated histone H1b with alkaline phosphatase and subsequent acid-urea and capillary electrophoresis. The results illustrate that the application of HPCE to the analysis of histone modifications provides a new alternative to traditional gel electrophoresis.

Alkaline Phosphatase↗
PubMed1992

Side-branch occlusion during percutaneous transluminal coronary angioplasty.

Concentrations of creatine kinase (CK) MB mass and cardiac troponin T were measured in serial peripheral venous blood samples from 21 patients who underwent percutaneous transluminal coronary angioplasty (PTCA). Angiography showed side-branch occlusion during PTCA without clinical signs of myocardial injury in 5 patients. After PTCA, CKMB mass concentrations were substantially higher than normal in all 5 patients with side-branch occlusion, and troponin T concentrations were high in 3. By contrast, only 2 patients and 1 patient, respectively, without side-branch occlusion had slight rises in CKMB and troponin T. Release of the contractile protein troponin T reflects more severe damage to myocytes than simple leakage of CKMB. Therefore, myocardial damage induced by side-branch occlusion can be graded by measurement of troponin T in plasma.

Adult↗
PubMed1992

High-performance capillary electrophoresis of core histones and their acetylated modified derivatives.

By using high-performance capillary electrophoresis, we have successfully separated rat liver core histones into several subfractions. Inconvenient interactions of the highly basic proteins with the capillary wall were eliminated by a phosphate buffer system containing 0.03% hydroxyprophylmethylcellulose. Sample amounts of a few nanolitres were analysed within about 20 min. Multiacetylated histones H4 and H3 from induced Friend erythroleukaemic cells prepurified by h.p.l.c. were clearly separated into their non-acetylated and distinct acetylated forms. Our results illustrate that the application of capillary zone electrophoresis on its own or in combination with h.p.l.c. to the analysis of histones provides an important new alternative to traditional gel electrophoreses.

Acetylation↗
PubMed1992

Endothelin-1 in patients with complicated and uncomplicated myocardial infarction.

Endothelin-1 concentrations were measured in peripheral venous blood samples from 42 patients with acute myocardial infarction. In patients with ischemic or hemodynamic complications (n = 11), endothelin-1 concentrations were significantly higher already on admission (P = 0.008) and remained significantly higher until day 6 after admission compared to patients with uncomplicated infarctions (n = 31; P = 0.035). There were no close correlations between peak concentrations of endothelin-1 and creatine kinase or creatine kinase isoenzyme MB mass in either group. Only in complicated patients did left ventricular ejection fraction correlate closely and inversely with peak endothelin-1 concentrations (r = -0.71; P = 0.03). Therefore, plasma endothelin-1 concentrations in patients with acute myocardial infarction patients may reflect states of markedly depressed cardiac performance and recurrent myocardial ischemia.

Adult↗
PubMed1992

Calcitonin gene-related peptide in patients with and without early reperfusion after acute myocardial infarction.

Plasma concentrations of calcitonin gene-related peptide (CGRP), a potent regulator of vascular tone, creatine kinase, myoglobin, and cardiac troponin T were assessed in 31 patients with acute myocardial infarction. In patients who had sustained acute myocardial infarctions, maximum CGRP concentrations (median, 3.2 pmol/L; interquartile range, 1.5 to 4.8 pmol/L) were markedly elevated as compared with healthy control subjects (n = 23; median, 1.02 pmol/L; p = 0.02). However, no marked differences in CGRP levels were observed between patients with early reperfusion (n = 19; median, 3.5 pmol/L) and patients without early reperfusion (n = 12; median, 2.6 pmol/L; p = 0.96), as well as between those with congestive heart failure (n = 8; median, 3.9 pmol/L) and those without congestive heart failure (n = 23; median, 3.2 pmol/L; p = 0.62). CGRP did not correlate closely with myocardial protein release or hemodynamic parameters (heart rate and blood pressure) or the occurrence of arrhythmias. Therefore we conclude that elevated peripheral venous CGRP concentrations in patients who have sustained an acute myocardial infarction are independent of successful reperfusion and hemodynamic state. Although the cause of CGRP increase is not yet identified, CGRP may play a role in the regulation of coronary vascular tone in patients after acute myocardial infarction.

Adolescent↗
PubMed1992

Atrial natriuretic factor release during hypovolemia and after volume replacement.

OBJECTIVE: To examine plasma atrial natriuretic factor activity during hypovolemia and after vascular volume replacement. DESIGN: Prospective, descriptive study. SETTINGS: Scene of emergency, Emergency Department, and the ICU of a university hospital. PATIENTS: A total of 47 trauma patients with evidence of hypovolemia were grouped according to their major injury into a thoracic injury group (15 patients; mean Injury Severity Score = 38.5 +/- 3.1 [SEM], Hospital Trauma Index = 14.1 +/- 0.7), an abdominal injury group (14 patients; Injury Severity Score = 36 +/- 3.3, Hospital Trauma Index = 14 +/- 0.9), and a severe head injury group (18 patients; Injury Severity Score = 23 +/- 1.5, Hospital Trauma Index = 10 +/- 0.6). MEASUREMENTS AND MAIN RESULTS: Measurements were taken at the scene of emergency; after volume replacement in the Emergency Department; and after 3, 7, 12, 24, 36 hrs and on day 5 in the ICU. In all groups, the average plasma atrial natriuretic factor levels were increased at the scene of emergency and declined significantly to normal values with volume replacement. In the thoracic injury group, plasma atrial natriuretic factor activity decreased from 253 +/- 73 to 115 +/- 83 pg/mL (p less than .0017); in the abdominal injury group, plasma atrial natriuretic factor activity decreased from 194 +/- 42 to 91 +/- 24 pg/mL (p less than .006); in the severe head injury group, plasma atrial natriuretic factor activity decreased from 167 +/- 28 to 70 +/- 13 pg/mL (p less than .02) with volume replacement. Plasma atrial natriuretic factor levels at the scene of emergency were significantly (252 +/- 73 vs. 167 +/- 28 pg/mL; p less than .05) higher in the thoracic injury group and in the abdominal injury group (194 +/- 42 vs. 167 +/- 28 pg/mL; p less than .05), as compared with the severe head injury group. CONCLUSIONS: In trauma patients, plasma atrial natriuretic factor concentrations were markedly increased in patients with untreated hypovolemia and were decreased to normal values with vascular volume replacement. Thus, atrial natriuretic factor seems to play an important physiologic role during hypovolemia.

Abdominal Injuries↗
PubMed1992

Early diagnosis of acute myocardial infarction by a newly developed rapid immunoturbidimetric assay for myoglobin.

OBJECTIVE: To evaluate a rapid immunoturbidimetric assay for myoglobin and to investigate its clinical usefulness in the early detection of acute myocardial infarction. DESIGN: Prospective study. Immunoturbidimetrically determined myoglobin concentrations were compared with radioimmunoassay results obtained with the same blood samples. The diagnostic performance of myoglobin determination was compared with creatine kinase and creatine kinase MB activity (current standard of routine diagnosis). SETTINGS: Part 1: coronary care unit. Part 2: emergency room in a university hospital. PATIENTS: Part 1:30 patients with acute myocardial infarction admitted not later than four hours (median two hours) after the onset of symptoms. Part 2: 126 patients admitted to the emergency room with chest pain not caused by trauma (51 cases of acute myocardial infarction, 51 cases of angina pectoris, and 24 cases of chest pain not related to coronary artery disease). INTERVENTIONS: Part 1: routine treatment including intravenous thrombolytic treatment (28 patients). Part 2: routine emergency treatment without thrombolytic treatment. MAIN OUTCOME MEASURES: The analytical quality of the immunoturbidimetric myoglobin assay and a comparison between the myoglobin assay and creatine kinase and creatine kinase MB for diagnostic sensitivity and performance. RESULTS: The immunoturbidimetric myoglobin assay was fast and convenient and gave myoglobin determinations of high analytical quality. The concentration of myoglobin increased, peaked, and returned to the reference range significantly earlier than creatine kinase (p < or = 0.0001) and creatine kinase MB (p < or = 0.0002). Before thrombolytic therapy was started the diagnostic sensitivity of myoglobin was significantly higher than that of creatine kinase MB activity 0-6 h after the onset of chest pain and significantly higher (0.82 v 0.29) than creatine kinase 2-4 h after the onset of chest pain. In almost all patients (92%) plasma myoglobin concentrations were increased 4-6 h after the onset of chest pain. CONCLUSION: Myoglobin was more sensitive in detecting early myocardial infarction than creatine kinase and creatine kinase MB activity. Immunoturbidimetric myoglobin measurements could be useful in the early evaluation of patients with suspected myocardial infarction because this assay takes less than two minutes.

Clinical Enzyme Tests↗
PubMed1992

Effects of exercise on plasma myosin heavy chain fragments and MRI of skeletal muscle.

The effects of a single series of high-force eccentric contractions involving the quadriceps muscle group (single leg) on plasma concentrations of muscle proteins were examined as a function of time, in the context of measurements of torque production and magnetic resonance imaging (MRI) of the involved muscle groups. Plasma concentrations of slow-twitch skeletal (cardiac beta-type) myosin heavy chain (MHC) fragments, myoglobin, creatine kinase (CK), and cardiac troponin T were measured in blood samples of six healthy male volunteers before and 2 h after 70 eccentric contractions of the quadriceps femoris muscle. Screenings were conducted 1, 2, 3, 6, 9, and 13 days later. To visualize muscle injury, MRI of the loaded and unloaded thighs was performed 3, 6, and 9 days after the eccentric exercise bout. Force generation of the knee extensors was monitored on a dynamometer (Cybex II+) parallel to blood sampling. Exercise resulted in a biphasic myoglobin release profile, delayed CK and MHC peaks. Increased MHC fragment concentrations of slow skeletal muscle myosin occurred in late samples of all participants, which indicated a degradation of slow skeletal muscle myosin. Because cardiac troponin T was within the normal range in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for an injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Muscle action revealed delayed reversible increases in MRI signal intensities on T2-weighted images of the loaded vastus intermedius and deep parts of the vastus lateralis. We attributed MRI signal changes due to edema in part to slow skeletal muscle fiber injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Cardiac troponin T in the diagnosis of myocardial injury.

In the last several decades serum levels of cardiac enzymes and isoenzymes have become the final arbiters by which myocardial damage is diagnosed or excluded. Because conventionally used enzymes are neither perfectly sensitive nor specific, there is need for a new sensitive and cardiospecific marker of myocardial damage. Cardiac troponin T (TnT) is a contractile protein unique to cardiac muscle and can be differentiated by immunologic methods from its skeletal-muscle isoform. An enzyme immunoassay specific for cardiac TnT is now available in a commercial kit for routine use. The biggest advantage of this assay is its cardiospecificity. TnT measurements, however, are also highly sensitive in diagnosis of myocardial injury and accurately discern even small amounts of myocardial necrosis. TnT measurements are, therefore, particularly useful in patients with borderline CK-MB and in clinical settings in which traditional enzymes fail to diagnose myocardial damage efficiently because of lack of specificity--for example, perioperative myocardial infarction or blunt heart trauma. TnT release kinetics reveal characteristics of both soluble, cytoplasmic, and structurally bound molecules. It starts to increase a few hours after the onset of myocardial damage and remains increased for several days. TnT allows late diagnosis of myocardial infarction. The diagnostic efficiency remains at 98% until 6 d after the onset of infarct-related symptoms. TnT is also useful in monitoring the effectiveness of thrombolytic therapy in myocardial infarction patients. The ratio of peak TnT concentration on day 1 to TnT concentration at day 4 discriminates between patients with successful (greater than 1) and failed (less than or equal to 1) reperfusion. TnT measurements are very sensitive and specific for the early and late diagnosis of myocardial damage and could, therefore, provide a new criterion in laboratory diagnosis of the occurrence of myocardial damage.

Biomarkers↗