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Biomedical subjects

M Panteghini

Publications and source records attributed to M Panteghini.

At least 55 records · Page 3Linked to original sources
PubMed1998

Standardization activities of markers of cardiac damage: the need of a comprehensive approach.

The field of biochemical markers of cardiac damage is in a dynamic state, with new applications continually appearing and new assays and markers being developed, but also with several analytical and interpretative problems to resolve. In this situation it is essential that a uniform and rigorous outlook be maintained to ensure optimal test utilization. For these reasons, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) agreed to establish a Committee on 'Standardization of Markers of Cardiac Damage' (C-SMCD). The first task of the C-SMCD concerns coordination of the different activities from affiliated associations, with (1) a review of documents and recommendations and (2) supervision and, possibly, the take-over of the standardization activities. Second, the C-SMCD supports development of scientific programmes for forthcoming international meetings and congresses. The third task of the C-SMCD is development of specific additional projects to promote the rational use of cardiac markers and to identify new areas of research.

Biomarkers↗
PubMed1997

Rapid and specific immunoassay for cardiac troponin I in the diagnosis of myocardial damage.

We evaluated a new immunometric assay for the quantitation of cardiac troponin I with the Behring Opus analyzer. All assay steps are performed automatically by the analyzer, the complete procedure requiring 20 min for the first test result. Total precision (coefficient of variation) varied between 5.6% and 13.0%. Comparison with the Pasteur immunoenzymometric assay showed good correlation (r = 0.959), but the Opus assay gave approximately tenfold higher values. Cardiac troponin I was undetectable (< 0.5 microgram/l) in sera from healthy subjects (n = 46), patients with severe skeletal muscle damage (n = 8), and all but 1 patient with chronic renal failure (n = 39). In patients with myocardial infarction (n = 21), investigated for 4 days after onset by frequent sampling, cardiac troponin I peaked at 20.8 +/- 8.1 h after onset with a mean concentration of 164.8 +/- 361.3 micrograms/l, remaining elevated in 89% of patients on the 4th day. In patients with unstable angina (n = 15), cardiac troponin I measurement was valuable in predicting the type of lesion morphology on coronary angiography and the short-term outcome.

Adult↗
PubMed1996

Biological variation in urinary excretion of pyridinium crosslinks: recommendations for the optimum specimen.

We assessed the analytical and biological variation of pyridinium crosslinks in early morning, 2 h fasting, and 24 h urine specimens from 14 healthy adults over a 1 month period. The results were expressed both in terms of pyridinoline concentration and pyridinoline/creatinine ratio. The data obtained were used to select the optimum specimen for clinical purposes. We found that: (a) early morning specimens are preferred; (b) results should be expressed as pyridinoline/creatinine ratio; (c) reference intervals should be stratified according to gender; (d) the necessary analytical imprecision (CV < or = 9%), derived from biological variation, is not easily achieved by current methods; (e) the difference between serial results from an individual must be > 50% to be statistically significant; and (f) assessment of risk for osteoporotic fracture by means of the pyridinium crosslink assay would, in a significant number of patients, require analysis of multiple urine specimens.

Adult↗
PubMed1996

[Cardiac troponin I and T in unstable angina: incidence, correlation, kinetics of release and prognostic value].

BACKGROUND: The aim of this study was to ascertain the incidence of altered serum cardiac Troponin-T (cTnT) and cardiac Troponin I (cTnI) in patients with unstable angina, the concordance between findings for the two proteins, their release kinetics and their utility in predicting coronary events. METHODS: We studied 32 consecutive patients (pts) admitted to the Coronary Unit with a diagnosis of unstable angina; following Braunwald classification criteria, 5 pts were in class I, 4 class II, 23 class III. A blood sample was taken on admission to hospital and subsequently every 8 hours for two days, a total of 7 samples being obtained per pt. Cardiac-TnT values ranging from 0-0.17 mugr/L (Boehringer Mannheim) were considered normal, as were cTnI values ranging from 0 to 0.7 mugr/L (Stratus-Dade). RESULTS: Among 218 samples, altered cTnT values (0.18-0.68 mugr/L) were found in 19 (3 pts), and 13 of these samples were positive for cTnI (0.8-5.5 mugr/L), while the remaining 6 showed borderline values for cTnI (0.5-0.7 mugr/L). No cTnT negative samples were found to be positive for cTnI. The release kinetics of cTnT and cTnI were comparable in all three cases, with a "plateau" pattern, unlike the kinetics in the course of acute myocardial infarction (AMI). The mean follow-up was 13 months on average (range 1-19). In two pts with altered cTnT and cTnI values, symptoms were controlled with medical therapy, while the remaining patient failed to respond to medical therapy and therefore underwent PTCA. Fifteen months later, they are alive and have not had myocardial infarction. Of the 29 pts with normal cTnT and cTnI values, three developed AMI, which in two cases was fatal. Seven pts were submitted PTCA, seven to aorto-coronary bypass surgery, two were subsequently rehospitalized for a recurrent angina symptoms. In 13 pts complete control of symptoms was achieved with medical therapy. CONCLUSIONS: Our findings demonstrate that the incidence of altered cTnT and cTnI values in pts with unstable angina is low; there is close agreement between findings for the two proteins; in cases of angina, the cTnT and cTnI release kinetics are different from those in AMI. The finding of altered cTnT and cTnI values in the serum of our pts with unstable angina does not appear to be of prognostic value for future coronary events.

Adult↗
PubMed1995

Nonenzymic glycation of apolipoprotein B in patients with insulin- and noninsulin-dependent diabetes mellitus.

OBJECTIVE: To evaluate the level of nonenzymatic glycation of apolipoprotein B in patients with insulin and noninsulin dependent diabetes mellitus. METHODS: Using a method based on a combination of affinity chromatography and immunonephelometry, we measured the concentration of glycated apolipoprotein B (apo B) in serum of 140 diabetic patients, 43 insulin-dependent (IDDM), and 97 noninsulin-dependent (NIDDM), and 45 nondiabetic control subjects. RESULTS: Although total apo B concentration in serum was significantly increased only in NIDDM patients, both groups of diabetics showed higher percentages of glycated apo B (IDDM, 4.84 +/- 0.8%; NIDDM, 5.61 +/- 1.1%) than did control subjects (4.28 +/- 1.0%), the greatest percentage (5.80%) being found in patients with diabetic nephropathy. No significant correlations were found between glycated apo B and the traditional parameters of glycemic control, such as glycated hemoglobin and fructosamines, and direct influence by sudden plasma glucose fluctuations on apo B glycation was not shown either, perhaps for a low inherent glycability of this apolipoprotein. CONCLUSIONS: It is unclear if these low proportions of glycated apo B in vivo may significantly affect lipoprotein metabolism assuming a pathophysiological role in atherogenesis.

Adolescent↗
PubMed1995

Enzyme and muscle diseases.

Two distinct areas of development contribute to the importance of enzymology in skeletal muscle disease: the measurement of enzymes in serum as a diagnostic aid and the investigation of enzyme deficiencies as the cause of metabolic myopathy. Currently, serum enzyme measurement, particularly creatine kinase, is used to aid in the detection of suspected myopathy, to differentiate myopathy from neurogenic disease, to identify dystrophies at a preclinical stage, to detect female carriers of dystrophies, and to assess response to therapy. Metabolic myopathies are disorders of muscle energy production that result in skeletal muscle dysfunction. The biochemical basis of such disorders is often a specific single enzyme defect. The tremendous advances in the molecular genetics of such disorders has added remarkably to our understanding of the primary defects involved and possible heterogeneity displayed at the molecular level.

Animals↗
PubMed1995

Biological variation in bone-derived biochemical markers in serum.

Analytical, within-subject and between-subject components of variation have been determined for total alkaline phosphatase (ALP) and its bone isoform, osteocalcin, and tartrate-resistant acid phosphatase (TR-ACP) in serum specimens from a cohort of 10 healthy subjects over a 1-month period. From these data, we have calculated the desirable analytical imprecisions, the indices of individuality, the critical differences for significant change detection, and the number of specimens required to estimate the homeostatic setpoint of an individual. For total ALP and its bone isoform, most of the observed variability was biologic, whereas osteocalcin and TR-ACP also had relatively high analytical variability. Total and bone ALP were also the parameters showing the lowest within-subject variability, whereas TR-ACP showed the lowest interindividual fluctuation. Osteocalcin and bone ALP had marked individuality, showing that the use of population-based reference limits is inadequate for their interpretation. The applicable differences required for two results to be significantly different (p < or = 0.05) are bone ALP: 20%; osteocalcin: 29%; and TR-ACP: 35%. The results demonstrate that the biochemical markers of bone turnover studied are of limited use to screen for metabolic bone disorders, but can be useful adjuncts for monitoring groups of patients in longitudinal studies.

Acid Phosphatase↗
PubMed1994

Determination of glycated apolipoprotein B in serum by a combination of affinity chromatography and immunonephelometry.

We have developed and optimized a procedure for the quantitation of non-enzymatically glycated apolipoprotein B (apo B). Glycated and non-glycated apo B were separated from serum using m-aminophenylboronate affinity chromatography, determined by immunophelometry and the percentage of glycated apo B was calculated. The measuring range of the assay was 2.9-185 mg/dL apo B. The within- and between-run coefficients of variation were < 7.4% and 14.6%, respectively, and recovery was > 98%. Free glucose in serum did not affect the results at concentrations below 25 mmol/L. In 45 non-diabetic subjects the mean concentration of glycated apo B was 4.3% (SD 1%). In type 1 (n = 17) and Type 2 (n = 60) diabetic patients the mean glycated apo B concentrations were 5.3% (SD 0.7%) and 5.9% (SD 1.1%), respectively, significantly higher than in controls (P < 0.001).

Adult↗
PubMed1994

An immunoinhibition assay for determination of creatine kinase isoforms in serum.

We report a preliminary evaluation of an immunoinhibition assay for creatine kinase isoform quantification. The procedure employs the monoclonal antibody CKM-G01, which inhibits the native M subunit of creatine kinase. The antibody does not inhibit the M subunit modified by removal of lysine by plasma carboxypeptidase N. Residual activity after treatment with the antibody is therefore due to serum delysinated isoforms. The ratio inhibited/residual activity correlated directly with the ratio tissue/serum isoforms. Analysis of the total imprecision of isoform ratio measurement gave a coefficient of variation between 5.9 and 21.1%. Reference intervals for the ratio were 0.14-0.79 in females and 0.19-0.95 in men (p = 0.0046). Analytical and clinical comparison with alternative isoform procedures gave good results, showing that this assay can be used as alternative to the widely accepted electrophoretic method for measurement of the creatine kinase isoform ratio.

Adult↗
PubMed1994

Electrophoretic fractionation of 5'-nucleotidase.

Human isonucleotidases were separated by electrophoresis on a cellulose acetate membrane. Three 5'-nucleotidase forms, NTP1, NTP2, and NTP3, were resolved with this method and quantified by densitometry. The procedure was not only simple and rapid but also sufficiently precise (between-run CV < 20%) and sensitive (detected nucleotidase fractions of > 0.5 U/L). The effects of various treatments (heat, neuraminidase, glycosidases, proteases, lectins, and detergents) on the electrophoretic pattern of 5'-nucleotidase were studied. NTP1 (mean 12% of total 5'-nucleotidase, SD 5%), NTP2 (mean 30%, SD 8%), and NTP3 (mean 58%, SD 8%) were found in all normal persons studied. The increase in total 5'-nucleotidase in patients with hepatobiliary disease was mainly due to the NTP1 isoform.

5'-Nucleotidase↗