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Biomedical subjects

B Puschendorf

Publications and source records attributed to B Puschendorf.

At least 19 recordsLinked to original sources
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↗
PubMed1991

Early detection of acute myocardial infarction by measurement of mass concentration of creatine kinase-MB.

The diagnostic sensitivity and performance of immunoenzymometric measurements of creatine kinase (CK)-MB mass concentrations in the early diagnosis of acute myocardial infarction (AMI) were examined and compared with the sensitivities and performances of CK and CK-MB activity, in the context of simultaneous measurements of CK, CK-MB activity, and CK-MB mass concentrations in serially drawn blood samples obtained immediately from 36 patients with AMI and 126 patients with chest pain on admission to the emergency room of the department of internal medicine. In the 36 patients with AMI, who were all admitted no later than 4 hours after the onset of chest pain, pathologic increase occurred significantly earlier in CK-MB mass than in both CK and CK-MB activity, with a median difference of 1 hour each. In patients coming to the emergency room (51 with AMI, 51 with angina pectoris and 24 with chest pain not related to coronary artery disease), CK-MB mass was the best diagnostic measurement for AMI of all markers tested (significantly higher efficiency, Youden index and likelihood ratio than both CK and CK-MB activity). Before initiating thrombolytic therapy, the sensitivity of CK-MB mass is significantly higher than CK-MB activity during the 0- to 6-hour period and significantly higher than CK activity during the 2- to 4-hour period after the onset of chest pain. Consequently, it is often possible to diagnose an AMI on the basis of increased CK-MB mass concentrations even at a time when CK and CK-MB activities are still within the reference interval.

Adult↗
PubMed1991

Possible role of histone acetylation and histone H1(0) replacement for the initiation of replication in regenerating rat liver.

The role of histone acetylation and DNA synthesis has been investigated extensively in the regenerating rat liver system in the presence and absence of the cyclophosphamide derivative mafosfamide. We demonstrate a mafosfamide-induced inhibition of maximum histone acetyltransferase activity followed by a second elevation of enzyme activity and an accompanying total suppression of DNA synthesis for 7-8 h. The maximum of histone acetyltransferase activity, in parallel with an elevated acetylation in vivo, the consecutive replacement of histone H1(0) amd initiation of replication occur sequentially in the presence and absence of mafosfamide, but with a temporary delay of 7-8 h. Our data indicate that modifications of histone acetyltransferase (EC 2.3.1.48) activity do not significantly influence the acetylation patterns of histones H3 and H4. The mafosfamide-induced change of histone acetyltransferase activity and acetylation in vivo, the shift of histone H1(0) exchange and the consecutive transition of initiation of replication suggest that these three events might be functionally related.

Acetylation↗