PubMed Health⌕ Search

Biomedical subjects

M Panteghini

Publications and source records attributed to M Panteghini.

106 records · Page 6Linked to original sources
PubMed1986

Evaluation of a new method for cholinesterase determination.

We report the evaluation of a new commercially available assay system for determination of the catalytic activity of serum cholinesterase (EC 3.1.1.8) and application of the method to a centrifugal fast analyzer. Serum cholinesterase activity is determined at 30 degrees C using para-hydroxybenzoylcholine as substrate. This reaction is coupled to a second reaction using para-hydroxybenzoate hydroxylase (EC 1.14.13.2) as coupling enzyme. Enzyme activity is measured kinetically by monitoring the decrease in absorbance at 340 nm of NADPH in the second reaction. The procedure is precise and the results obtained from normal and pathological sera show good correlation with those obtained by the alternative procedures employing propionylthiocholine, butyrylthiocholine and benzoylcholine as substrates. The reference range for 700 healthy subjects was estimated to be 140-345 U/L (95% central range, determined non-parametrically), with significant difference between males and females (155-353 U/L for men and 134-323 U/L for women, p less than 0.001).

Acetylcholinesterase↗
PubMed1986

Serum enzymes in acute myocardial infarction after intracoronary thrombolysis.

Serum kinetics of total creatine kinase (CK), CK-MB isoenzyme, aspartate aminotransferase (AST), lactate dehydrogenase (LD) and alpha-hydroxybutyrate dehydrogenase (HBD) activities were studied in twenty patients with acute myocardial infarction randomly assigned to receive either intracoronary urokinase (group A) or conventional (control) therapy (group B). The temporal characteristics of enzyme changes described were the time lag from onset of chest pain until maximum catalytic concentration value, the rate at which enzymes are released into blood, the peak value of the serum enzyme curves and (d) the fractional disappearance rate (Kd) for each enzyme considered. Thrombolytic treatment induced earlier peak times in group A: for CK, 10.8 vs 27.0 h, for CK-MB, 10.4 vs 23.1, for AST, 13.9 vs 31.3, for LD, 24.4 vs 49.1, and for HBD, 20.5 vs 48.5 (for all enzymes, p less than 0.001). The maximal rate of release for the enzymes was at least twofold greater in group A. Enzyme peak activities and Kd were not significantly different between the groups. The most significant discrimination between the two groups was obtained with AST peak time (Hartz overlap index (Oi) = 0.11) and CK-MB peak time (Oi = 0.12).

Adult↗
PubMed1986

Evaluation of the direct potentiometric method for serum chloride determination--comparison with the most commonly employed methodologies.

A new instrument (NOVA 4 + 4) designed to measure serum chloride by ion-selective electrode (ISE)-direct potentiometry (without sample dilution) was evaluated and compared with two widely used methodologies for chloride determination. Mean values obtained with the Nova were significantly higher than those obtained by a colorimetric method and by coulometric titration. Unlike these procedures, which are performed after sample dilution, direct potentiometry was unaffected by changes in plasma water caused by hyperlipemia and/or high protein concentrations. The only important interference was falsely high choride caused by administered bromide or iodide. Therefore, the direct potentiometric method should be more accurate than the colorimetric or coulometric procedures, especially when plasma lipids or proteins are very high.

Blood Proteins↗
PubMed1986

Evaluation of a commercial immunoenzymometric assay kit for creatine kinase MB isoenzyme determination using monoclonal antibodies.

A simultaneous two-site immunoenzymometric assay for creatine kinase MB determination (Hybritech Tandem-E CK-MB) using monoclonal antibodies was evaluated and compared with cellulose acetate electrophoresis using fluorometric scanning densitometry. The assay has satisfactory precision (between-day analysis gives a coefficient of variation between 2.1 and 9.4%) and is not susceptible to interference by concentrations of creatine kinase MM up to 5000 micrograms/l (3400 U/l) and creatine kinase BB up to 1000 micrograms/l (1085 U/l). The upper limit of MB isoenzyme concentration in 250 apparently healthy people was 5.5 micrograms/l. Comparison between the immunoenzymometric assay (y) and electrophoresis (x) yielded the following linear regression equation: y = 0.37x + 1.9, with a correlation coefficient of 0.828. The characteristics of the temporal kinetics of MB isoenzyme, calculated by two methods, in 49 patients with acute myocardial infarction, were nearly identical in terms of the rate of creatine kinase MB release and the time at which the peak value is obtained, but not in terms of the rate of elimination of the isoenzyme. The fractional disappearance rate of MB isoenzyme from the circulation was significantly higher if calculated with Tandem-E results rather than with electrophoresis results (-0.035 vs -0.028, p less than 0.001). Whereas in the first day after infarction immunoenzymometric assay and electrophoresis had the same clinical sensitivity for identifying patients with acute myocardial infarction, in specimens collected more than 24 hours after the onset of the chest pain, the clinical sensitivity of the immunoenzymometric method was lower. Our results show that it is still premature to draw definitive clinical conclusions from the immunoassay results.

Adult↗
PubMed1984

Evaluation of a new continuous colorimetric method for determination of serum pseudocholinesterase catalytic activity and its application to a centrifugal fast analyser.

We report the evaluation of a new commercially available assay system for the determination of serum pseudocholinesterase (EC 3.1.1.8) catalytic activity, and its application to a kinetic analyser. The assay is based on the colorimetric method of Okabe et al. (Clin. Chim. Acta 80, 87-94 (1977]: choline, liberated from benzoylcholine by pseudocholinesterase, is oxidized by choline-oxidase (EC 1.1.3.17) to betaine with the simultaneous production of hydrogen peroxide, which oxidatively couples with 4-aminoantipyrine and phenol in the presence of peroxidase to yield a coloured compound with maximal absorbance at 500 nm. The procedure not only has the advantage of being continuous, colorimetric and totally enzymatic but also appears to be precise (between-day analysis gives coefficient of variation between 3.5 and 5.6%) and accurate; the results obtained from normal and pathological sera show excellent correlation with those obtained by the alternative procedures employing propionylthiocholine, acetylthiocholine and butyrylthiocholine as substrates.

Butyrylcholinesterase↗
PubMed1984

Clinical and diagnostic significance of aspartate aminotransferase isoenzymes in sera of patients with liver diseases.

Serum aspartate aminotransferase isoenzymes were measured in 123 hospital patients with various liver diseases, using a new and simple immunochemical method. Our findings show the usefulness of this determination in estimating the severity of hepatic damage, especially if accompanied by the measurement of other mitochondrial enzymes. During hepatic damage, the cytoplasmic isoenzyme is found in greater quantities than the mitochondrial isoenzyme, but the level of the latter increases to a greater extent in acute liver diseases. Moreover, the values of mitochondrial aspartate aminotransferase activity and the ratio of mitochondrial to total aspartate aminotransferase in alcoholic hepatitis are higher than expected if so-called hepatic enzymes commonly measured in serum are considered. These results indicate that there is significant mitochondrial damage in alcoholic hepatitis.

Adult↗
PubMed1983

Determination of aspartate aminotransferase isoenzymes in hepatic diseases--preliminary findings.

The study sought to establish a relationship between the AST isoenzyme levels in serum and degree of hepatic damage, by using a new and simple immunochemical method for the differential determination of the isoenzymes. Sixty-nine patients with various hepatic diseases were studied. During hepatic damage, cytoplasmic isoenzyme (s-AST) is found in greater quantities than mitochondrial isoenzyme (m-AST), but the m-AST level increases to a greater extent in acute liver diseases. However, m-AST in alcoholic hepatitis is higher than expected from the total AST (t-AST) values. The ratio of m-AST to t-AST seems to discriminate alcoholic hepatitis from other liver diseases.

Adult↗
PubMedDate not supplied

Clinical and analytical performance of automated immunochemiluminometric assays for determination of cardiac markers in serum.

Three new immunochemiluminometric assays for quantitation of cardiac markers, i.e., creatine kinase isoenzyme MB (CK-MB), myoglobin and cardiac troponin I (cTnI), were evaluated with the Sanofi Access analyser. The complete profile requires 20 min to perform, the method being suitable in true stat situations. In patients with early myocardial infarction (median time of sample collection: 210 min from onset, range 30-450; n = 44), the diagnostic sensitivity of Access cTnI was 66%, compared with 80% for myoglobin, and 43% for CK-MB. For comparison, cTnI, with an automated immunofluorimetric assay was also measured (sensitivity, 45%; p < 0.05 vs. Access cTnI). Our data confirmed myoglobin as the first biochemical marker to appear elevated after infarction. However, cTnI may be a more sensitive marker for early detection of cardiac damage than initially thought, when determined by an ultrasensitive method such as an immunochemiluminometric assay.

Adult↗
PubMedDate not supplied

The sensitivity of cardiac markers: an evidence-based approach.

The aim of this study was to determine whether, using an evidence-based approach, the results of the papers found in the literature are valid and sufficiently scientifically rigorous to be used to definitely address the problem of cardiac marker sensitivity in detection of acute myocardial infarction. In particular, the diagnostic sensitivities of myoglobin, creatine kinase (CK)-MB isoenzyme, determined as mass concentration, CK-MB isoforms, and of the two cardiac troponins, troponin I and troponin T, were reviewed using a priori formulated inclusion/exclusion criteria for judging the eligibility of studies to be included in the analysis. A clear final message derived from this systematic analysis is the unacceptably poor diagnostic sensitivity of all evaluated markers at patient admission, with substantial failure rate to rule out myocardial infarction at this time. Myoglobin is at present the most sensitive of the markers studied for excluding early AMI with an optimum timing of sampling at patient presentation and approximately 4 h later. However, this marker cannot be used by itself as a proportion of patients admitted to the hospital with a late infarction could be missed. The early rate of rise of CK-MB mass and troponin T is similar. Maximum sensitivity of these two parameters is achieved by the analysis of a second sample 6 to 12 h after admission. Additional larger studies are needed to address the question which troponin shows earlier release after myocardial damage, and to clarify the role of CK-MB isoforms as a possible early marker of myocardial infarction.

Biomarkers↗
PubMedDate not supplied

Diagnostic value of prostatic acid phosphatase and prostate-specific antigen in patients with prostatic cancer.

To compare the clinical usefulness of the measurement of prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA) in serum of patients with prostatic carcinoma, we studied 128 patients with prostatic pathology, sixty (46.9%) of whom had prostatic cancer. Receiver-operating characteristics (ROC) curves were constructed and the underlying areas were calculated and compared to study clinical efficiency of the two markers regardless of the cutoff level selected. The area for PSA (0.90 +/- 0.30) was significantly higher (p less than 0.001) than that of PAP (0.71 +/- 0.05) showing that PSA was a better discriminator of the patients with or without prostatic cancer. The maximal clinical efficiency of the two tests at selected cutoff levels (0.8 U/L for PAP and 10 micrograms/L for PSA) was 0.787 and 0.883, respectively, confirming the superiority of PSA. However, the associated determination of the two markers improved the clinical specificity with no false-positive cases.

Acid Phosphatase↗
PubMedDate not supplied

[Inhibitory action of Hodgkin's disease patients serum on T lymphocytes E rosette forming ability (author's transl)].

We have studied the E rosette forming-phenomenon on normal and pathologic lymphocytes after 24 hours of incubation in Fetal Calf Serum. The percentage of E rosette forming cells decreases more after incubation in Hodgkin's disease patients serum than in normal control serum. The findings suggest a specific interaction between serum factors and Hodgkin's disease lymphocytes surface receptors.

Hodgkin Disease↗