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Query: UMLS:C0018801 (
heart failure
)
72,216
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Methods of glomerular filtration rate measurement by 51Cr
EDTA
elimination, inulin clearance and creatinine clearance were compared with and without captopril pretreatment in 10 chronic
heart failure
patients and in 20 patients after transmural myocardial infarction. Strong intermethod correlations were found in chronic
heart failure
patients (
EDTA
: inulin r = 0.87;
EDTA
: creatinine r = 0.84; inulin: creatinine r = 0.9; all P less than 0.00001). Despite this, substantial absolute differences were observed in results obtained by different techniques. In particular, creatinine clearance significantly overestimated both 51Cr
EDTA
(18.0 +/- 18.4 ml.min-1, mean difference +/- SD, P less than 0.001) and inulin clearance (26.8 +/- 17.0 ml.min-1, P less than 0.001). The slight reduction in 51Cr
EDTA
elimination on captopril versus placebo (-8.3 +/- 9.2 ml.min-1, P less than 0.05) was related to a similar treatment difference in inulin clearance (r = 0.67, p = 0.03), but changes observed by either method were unrelated to captopril-induced changes in creatinine clearance. Thus, creatinine clearance is an unsatisfactory means of assessing the effect of angiotensin converting enzyme inhibition on glomerular filtration rate in chronic
heart failure
. In the post-myocardial infarction group, correlations between methods were poorer (
EDTA
: inulin r = 0.79;
EDTA
: creatinine r = 0.76; inulin: creatinine r = 0.67). In this group no significant effect of captopril on glomerular filtration rate was detected by any technique. As compared to the chronic
heart failure
patients, the weaker relationship between techniques post-myocardial infarction may be related to interference by thrombolytic or aspirin treatment.
...
PMID:Comparison of three methods of glomerular filtration rate measurement with and without captopril pretreatment in groups of patients with left ventricular dysfunction. 139 29
In this study we tested the hypothesis that reduced myofibrillar ATPase activities in end-stage
heart failure
are associated with a redistribution of myosin isozymes. Cardiac myofibrils were isolated from left ventricular free wall from normal human hearts and hearts at end-stage
heart failure
caused by coronary artery diseases, cardiomyopathy or immunological rejection. The hearts had been excised in preparation for a heart transplant. Myofibrillar Ca2(+)-dependent Mg-ATPase and myosin Ca2(+)- and K+EDTA-ATPase activities were compared. Possible changes in myosin isozyme distribution in the diseased heart were investigated using polyacrylamide gel electrophoresis of native myosin in the presence of pyrophosphate. Significant reduction in myofibrillar Ca2(+)-dependent Mg-ATPase with no changes in the sensitivity of the myofibrils to Ca2+ was observed in heart with coronary artery diseases (25.2 to 27.1% at pCa 5.83 to pCa 5.05), cardiomyopathy (21.1 to 25.5% at pCa 5.41 to pCa 5.05), and in the immunologically rejected heart (18.4 to 22.8% at pCa 5.41 to pCa 5.05). Significantly lower myosin Ca2(+)-ATPase was observed with coronary artery diseases only and myosin K-
EDTA
activities did not differ in diseased and normal hearts. Polyacrylamide gel electrophoresis of native myosin from the normal and three models of end-stage
heart failure
revealed two distinct bands in the human left ventricle and one diffuse band in the human right atria. No apparent differences in myosin isoenzyme pattern were observed between the normal and diseased hearts. Further evaluation is needed to clarify the ATPase nature of the two bands.
...
PMID:Reduced cardiac myofibrillar Mg-ATPase activity without changes in myosin isozymes in patients with end-stage heart failure. 214 90
Eighteen consecutive patients, admitted with a diagnosis of dilated cardiomyopathy (DCM), to the Cardiology Section, Department of Internal Medicine, University Hospital, Uppsala, Sweden were enrolled into the study. All patients suffered signs of cardiac incompensation of variable duration. Patients were defined by conventional clinical investigations including chest X-ray, ultrasound, g-camera, catheterization and endomyocardial biopsy with histological evaluation by a specially trained pathologist. Angiography was performed to exclude ischemic heart disease. Several patients were diagnosed as having a specific reason for the
cardiac insufficiency
, like pheochromocytoma, SLE, ethylism, ischemic heart disease and hypertrophic cardiomyopathy. In this group all 7/7 had negative serology against Coxsackie B viruses. In the other group of idiopathic CM, no other etiology could be found. Serological analysis in this group showed high IgM titres against Coxsackie viruses in 6/8 patients.
EDTA
-blood was taken for tissue-typing using DNA probe hybridisation. 6/12 patients had DQB1:4 using the newest nomenclature, vs 17% in the control population. The reversed picture was observed for DQB1:2, occurring in 1/12 patients, vs 19% in the normal population, thus indicating a protective value of this genotype, which to our knowledge has not been described before. The results indicate a dual dependence of (host) genotype and (virus) serotype according to the Doherty-Zinkernagel hypothesis. Thus, it would also be in agreement with the virus-immune hypothesis suggested more than 20 years ago to explain the enigmatic pathogenesis of DCM.
...
PMID:Genotypic and serotypic profile in dilated cardiomyopathy. 839 Jul 21
A RIA for human brain natriuretic peptide (BNP) was developed. Both BNP and atrial natriuretic peptide (ANP) were extracted from human plasma with Vycor glass powder (71% recovery for BNP). The assay had a minimum detection limit of 0.45 fmol/tube and an IC50 of 9 fmol/tube. The within-assay coefficients of variation were 11.4% at 4 pmol/L and 3.2% at 22 pmol/L, and the between-assay coefficient of variation was 11% at 24 pmol/L. There was no significant loss of immunoreactive (IR)-BNP in plasma samples stored at -80 C for 4 weeks. Low rates of labeled BNP and IR-BNP degradation occurred in
EDTA
plasma incubated at 37 C. The mean venous plasma IR-BNP (6.3 +/- 0.3 pmol/L) in normal subjects (n = 48) was significantly lower than plasma ANP (8.4 +/- 0.6 pmol/L). In contrast to ANP, IR-BNP did not increase when normotensive or hypertensive subjects changed from erect to supine posture. Markedly elevated levels were found in patients with congestive heart failure (mean IR-BNP, 87 +/- 11 pmol/L; ANP, 87 +/- 12 pmol/L; n = 35), recent myocardial infarction (mean IR-BNP, 60 +/- 9 pmol/L; ANP, 33 +/- 6 pmol/L; n = 7), and chronic renal failure. High pressure liquid chromatography of plasma extracts from
heart failure
subjects revealed both high (mol wt, 10,000) and low (mol wt, 4,000) mol wt IR-BNP. High mol wt BNP was the major component (mean ratio, 1.9:1) and was linearly correlated with low mol wt BNP (r = 0.99). HPLC of plasma extracts from three normal subjects receiving constant infusions of human BNP (2 pmol/kg.min) showed a single major peak eluting in the position of hBNP-32, with no evidence of high mol wt material. These results show that whereas marked elevations in BNP occur in circulatory disorders, a major (> 50%) and consistent contribution to immunoreactivity is due to precursor forms. Further, compared to ANP, there is no IR-BNP response to supine posture in normal and hypertensive subjects.
...
PMID:Assay of brain natriuretic peptide (BNP) in human plasma: evidence for high molecular weight BNP as a major plasma component in heart failure. 847 92
We evaluated the analytical characteristics and clinical usefulness of a commercially available IRMA kit for measuring plasma concentrations of atrial natriuretic peptide (ANP) in healthy subjects and in patients with
heart failure
. The method uses two monoclonal antibodies prepared against sterically remote epitopes of the ANP molecule; the first antibody is coated on the solid-phase beads, and the second is radiolabeled with 125I. Fifty-nine healthy subjects and 77 patients with
heart failure
were studied. After subjects had rested 20 min in a recumbent position, blood samples were collected from a brachial vein into ice-chilled disposable polypropylene tubes containing aprotinin and
EDTA
. Plasma samples were immediately separated by centrifugation and stored at -20 degrees C until assay. The working range (CV <15%) was 10-2000 ng/L. The detection limit (2.13 +/- 0.91 ng/L) was similar to those reported for other IRMAs but was much better than those of RIAs. For healthy subjects, the results of this method (18.0 +/- 10.6 ng/L, range 4.7-63 ng/L, median 16.7 ng/L, n = 59) were similar to those generally reported for the most accurate methods, i.e., those using preliminary extraction and chromatographic purification of plasma samples. Measured plasma ANP was significantly associated with the severity of clinical symptoms, i.e., NYHA class (ANOVA, P <0.0001), and with the left ventricular ejection fraction (n = 62, r = 0.618, P <0.0001). Patients with severe
heart failure
showed greatly increased values (NYHA III-IV: 257.4 +/- 196.6 ng/L, n = 23).
...
PMID:Analytical performance and clinical usefulness of a commercially available IRMA kit for measuring atrial natriuretic peptide in patients with heart failure. 885 46
Very little is known about degradation or metabolism of adrenomedullin. To this end, we incubated adrenomedullin with ovine adrenal, kidney and lung plasma membrane preparations and showed the major degradation products were ADM(2-52) and ADM(8-52). Smaller amounts of ADM(26-52), (27-52), (28-52) and (33-52) were also produced. Degradation was inhibited by
EDTA
and 1,10 phenanthroline but not by phosphoramidon, leupeptin and pepstatin. The above data are consistent with initial hydrolysis adjacent to hydrophobic residues by a metalloprotease, generating ADM(8-52), (26-52) and (33-52), followed by an aminopeptidase action to produce ADM(2-52), (27-52) and (28-52). Improved understanding of the metabolism of ADM may have therapeutic implications, for example in the treatment of
heart failure
.
...
PMID:Degradation of human adrenomedullin(1-52) by plasma membrane enzymes and identification of metabolites. 921 69
A 66-year-old male patient was hospitalized for severe
heart failure
. Within 3 days after admission his platelet count dropped from 148 x 10(9)/l to 3 x 10(9)/l. Pseudothrombocytopenia was diagnosed based on the platelet count of 3 x 10(9)/l in K3-
EDTA
anticoagulated blood as opposed to 110 x 10(9)/l in sodium citrate. Platelet reactive antibodies were not detectable. To the best of our knowledge, this is the first report of a documented onset of pseudothrombocytopenia.
...
PMID:Documented sudden onset of pseudothrombocytopenia. 923 14
Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels increase in patients with
heart failure
with the progression of clinical symptoms and with the deterioration of hemodynamics; consequently, assay methods for these peptides may be useful in the follow-up of cardiac patients. Non-competitive immunoradiometric assay (IRMA) methods for ANP or BNP do not generally require preliminary extraction and/or purification of the plasma sample, and so may be more suitable than competitive immunoradiometric assay (RIA) methods for the routine assay of plasma peptide concentrations. We evaluated the analytical characteristics and clinical usefulness of two IRMAs for plasma ANP and BNP, to verify whether these methods may be considered suitable for the follow-up of patients with
heart failure
. Both methods are based on the solid-phase sandwich IRMA system, which uses two monoclonal antibodies prepared against two sterically remote epitopes of peptide molecule; the first antibody was coated on the beads solid-phase and the second was radiolabeled with 125I. Blood samples were collected from a brachial vein in ice-chilled disposable polypropylene tubes containing aprotinin and
EDTA
after the patient had rested for at least 20 min in the recumbent position. Plasma samples were immediately separated by centrifugation and stored at -20 C until assay. The IRMA methods showed a better sensitivity and a wider working range sensitivity (about 2 ng/l) than those of RIA methods. Moreover, the normal range found with these methods (ANP = 16.1 +/- 8.6 ng/l, 5.2 +/- 2.8 pmol/l, BNP = 8.6 +/- 8.2 ng/l, 2.5 +/- 2.4 pmol/l) was similar to that generally reported using the most accurate methods, such as the other IRMAs or RIAs, using a preliminary extraction and purification of plasma samples with chromatographic procedures. Our results obtained in patients with different degrees of
heart failure
indicate that plasma ANP and BNP increase with the progression of clinical symptoms (NYHA class) (ANOVA p < 0.0001). Indeed, circulating levels of ANP (R = -0.701, no. = 86) and BNP (R = -0.745, no. = 55) were significantly (p < 0.0001) and negatively correlated with the left ventricular ejection fraction values. Furthermore, a close curvilinear regression (R = 0.960, no. = 215) was found between ANP and BNP values, because plasma BNP progressively increases more than plasma ANP in patients with different stages of
heart failure
. In conclusion, IRMA methods are preferable for the measurement of plasma ANP and BNP for experimental studies and routine assay because they are more practicable, sensitive and accurate than RIA procedures. Finally, BNP assay appears to be better than ANP for discriminating between normal subjects and patients with different degrees of
heart failure
.
...
PMID:Circulating levels of cardiac natriuretic peptides (ANP and BNP) measured by highly sensitive and specific immunoradiometric assays in normal subjects and in patients with different degrees of heart failure. 959 Dec 13
Plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) are raised in patients with left ventricular dysfunction. Measurement of this peptide has a potential diagnostic role in the identification and assessment of patients with
heart failure
. The stability of this peptide over time periods and conditions pertaining to routine clinical practice has not been reported previously. Blood samples were obtained from 15 subjects. One aliquot was processed immediately, and the remaining portions of the blood samples were stored for 24 h or 48 h at room temperature or on ice prior to processing. Plasma concentrations of NT-proBNP were measured with a novel immunoluminometric assay developed within our laboratory. Mean plasma concentrations of NT-proBNP were not significantly different whether blood samples were centrifuged immediately and stored at -70 degrees C or kept at room temperature or on ice for 24 h or 48 h. The mean percentage differences from baseline (reference standard) were +5.2% (95% confidence interval +18.2 to -7.8%) and +0.8% (+15.2 to -13.7%) after storage for 24 h at room temperature or on ice respectively, and +8.9% (+24.2 to -6. 5%) and +3.2% (+15.1 to -0.9%) for storage for 48 h at room temperature or on ice respectively. Pearson correlation coefficients for baseline NT-proBNP concentrations compared with levels at 48 h at room temperature or on ice were r=0.89 and r=0.83 respectively (both P<0.0001). Thus NT-proBNP extracted from plasma samples treated with
EDTA
and aprotinin is stable under conditions relevant to clinical practice.
...
PMID:Assessment of the stability of N-terminal pro-brain natriuretic peptide in vitro: implications for assessment of left ventricular dysfunction. 1046 49
Brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP) and N-terminal ANP are good research indices of the severity of
heart failure
. The stability of these peptides at room temperature has become an important factor in assessing their use as indicators of cardiac function in routine clinical practice. Inhibitors such as aprotinin are routinely added in the blood collection process, but may provide no benefit in sample collection and routine clinical practice. We assessed the stability of BNP, ANP and N-terminal ANP in blood samples collected in either the presence or the absence of the protease inhibitor aprotinin. Blood, either with or without aprotinin, was processed immediately (initial; 0 h) and after blood samples had been left for 3 h, 2 days or 3 days at room temperature. These times were chosen to reflect processing in a hospital outpatient clinic (2-3 h), or when posted from general practice (2-3 days). Initial plasma BNP, ANP and N-terminal ANP levels in the absence of aprotinin were 28.2+/-5.4, 44.2+/-7.9 and 1997+/-608 pg/ml respectively, and were not significantly different from initial values in the presence of aprotinin (29.0+/-5.9, 45.2+/-8.0 and 2009+/-579 pg/ml respectively). After 3 h at room temperature, there was a significant fall in ANP in the absence of aprotinin (36. 7+/-7.9 pg/ml; P<0.005), but not in the presence of aprotinin (41. 2+/-7.6 pg/ml). Both BNP and N-terminal ANP were unchanged in either the absence (BNP, 27.6+/-5.5 pg/ml; N-terminal ANP, 2099+/-613 pg/ml) or the presence (BNP, 29.4+/-5.6 pg/ml; N-terminal ANP, 1988+/-600 pg/ml) of aprotinin. After 2 days at room temperature, ANP had fallen significantly in both the absence (16.9+/-3.4 pg/ml) and the presence (24.0+/-5.0 pg/ml) of aprotinin compared with initial values, and there was a significant difference in ANP levels in the absence and presence of aprotinin (P<0.001). ANP levels had decreased further after 3 days at room temperature, to 11.9+/-3.4 pg/ml (no aprotinin) and 20.3+/-5.0 pg/ml (aprotinin added); these values were significantly different (P=0.002). In contrast, there was no change in the levels of BNP or N-terminal ANP after 2 or 3 days at room temperature, in either the absence or the presence of aprotinin. These studies indicate that aprotinin adds little benefit to the stability of cardiac peptides at room temperature. Blood samples for BNP and N-terminal ANP measurement used as a test of heart function in hospital clinics and by general practitioners in the community could be taken into blood tubes containing only
EDTA
as anticoagulant and without the additional step of adding the routinely used inhibitor aprotinin.
...
PMID:Cardiac peptide stability, aprotinin and room temperature: importance for assessing cardiac function in clinical practice. 1058 96
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