Biomedical subjects
Publications and source records attributed to D Pelizzola.
Description of an analytical procedure in order to show the atypical-CK carriers that simulate an abnormal raising of CK-MB circulating levels in dosages for immune inhibition. This procedure was applied to two samples taken from patients of such a type, immune form neoplastic and cardiac pathology. A systematic dosage of a "real" MB isoenzyme is desirable in all the cases of very raised CK-MB activity.
Since 1979 the quality control design proposed by the Italian ad hoc Committee has evaluated several lyophilized preparations with scalar receptor content; this permits the identification by linear regression analysis of systematic and non systematic errors. At present 41 laboratories from most of the national regions have joined the Italian Committee. The overall results of five years application of quality assurance in Italy show that there was a different pattern of imprecision with satisfactory indexes for intralaboratory performances but major variations in interlaboratory controls. There was also a remarkable difference of variability indices between the so-called "expert" and "new" laboratories; this problem can be reduced with practical seminars for new centers. On the basis of the results and experience achieved the Committee is starting another program of quality assurance for different new methodologies to provide guidelines for international working reference standards.
The importance of evaluating receptors for estrogen and progestin in human breast cancer has been pointed out by many authors. In the absence of a reference standard, receptor assays must be controlled by intra and interlaboratory quality control programs. Much interlaboratory variability exists due to non-uniform analytical protocols, non-uniform ligands, intrinsic errors and also errors in computation methods. The goals of our Italian Quality Control Program on Multicenter Trials are to standardize the analytical procedures and computation methods. Twenty Italian laboratories participated in the Quality Control Program. Each specimen was assayed for steroid receptor content according to the standardized dextran-coated-charcoal method. Data were subjected to computerized analyses by 5 different methods of calculation (Scatchard plot, direct plot, Lineweaver-Burk method, Brunauer-Emmet-Teller analysis, single-point approach). The results were than evaluated to identify intra- and inter-assay variation coefficients and to define other statistical parameters. The authors suggest different calculation methods depending on the specific experimental and/or physiopathological conditions.
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The results of a screening for beta-heterozygous thalassemia conducted on 999 school-boys aged from 11 to 13 are the following: 7.5% of the subjects were taker of the thalassemia trait; 74 subjects over 75 with beta-heterozygous thalassemia had "Mean Corpuscolar Volume" (MCV) values below 70 fl. The results of the subjects with globular volume less than or equal to 79 fl (with or without beta-thalassemia) were used to compare the diagnostic accuracy of beta-thalassemia for the hematological indexes of England-Fraser, Mentzer, Shine-Lal and the MCV estimations. This comparison has shown better results in terms of sensibility and specificity for MCV with respect to the other indexes. A more extensive application of the study could be convenient in order to evaluate if the MCV level of 70 fl is effective to discriminate between beta-thalassemia and non thalassemic microcytosis.
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Administration of four different contrast media exerted slight but significant and prolonged effects on the hormonal thyroid status, in 53 euthyroid subjects (four subgroups), without any clinical expression of dysthyroidism. Changes in serum T3, rT3 and T4 demonstrated different trends for each iodinated compound, probably depending on the regulatory thyroid mechanisms, and CM pharmacokinetics. Plasma profiles of free fractions (FT3, FT4) slightly reflected consensual changes with circulating iodothyronines, at various time periods of study, demonstrating high correlation indexes with total fractions. The five hormones profiles correlation study suggest that different mechanisms could be responsible for some features encountered of "low T3 syndrome". These effects may be not only equivalent to giving various sources of iodide, but suggest more complex mechanisms. It is apparent that man has a remarkable and possibly unique system of homeostatic thyroid hormone regulation.
The possible relationships between hormone receptor status and several clinical (age, gynecologic history, clinical stage) and morphologic aspects (histologic grade, vascular invasion, lymphocytic infiltration, necrosis, fibrosis, elastosis and lymph node metastasis) were evaluated. A highly significant correlation between estrogen receptor levels, patient age, menses regularity and postmenopausal status was found. The histologic features most significantly related to tumor receptor status were histologic grade, lymphocytic infiltrate, necrosis and elastosis. Since these same histologic aspects appear to influence prognosis in breast cancer, the prognostic significance attributed to tumor receptor levels is substantiated. Therefore the importance of this assay is confirmed, not only for its diagnostic and therapeutic purposes, but also for its prognostic value.
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For nearly 60 years, since it was introduced by Graham and Cole (1924), oral cholecystography (OCG) has been used as the imaging technique of choice in investigation of gallbladder disorders. Recently, the future of OCG has come into doubt, principally as a result of ultrasonography, with the advent of high-resolution real-time scanning. Stones are seen as echoes within the lumen of the gallbladder and are associated with an acoustic shadow, findings which are highly specific. On this basis, to evaluate the accuracy of ultrasonography in detecting cholelithiasis, the A. have performed by real-time cholecystosonography 60 patients with not diagnostic OCG in a group of 546 patients affected by gallbladder diseases. Our results have confirmed that sonography revealed 4 normal gallbladders, 51 gallstones and 1 primary gallbladder cancer, with 5 cases of false positive. The true false negative rate has been difficult to determine, as surgery is usually not performed after a negative study. The accuracy of cholecystosonography for gallstone diagnosis was found to be 88,1% for all three Crade's categories.
The Coomassie-Blue method for protein determination is the EORTC uniformed technique for steroid receptor assay in tumor tissues. Many quality control trials have shown unacceptable interlaboratory variation coefficients for protein determination in steroid receptor assay. The objective of this study is to check the critical parameters of the method. The authors propose some suggestions on stability of dye-protein complex, ionic strength and temperature influence to improve the accuracy of the method.
This article presents results of the first Italian quality control program for determining the estradiol receptor on lypophilized guinea pig and calf uteri. Despite considerable variability in quantitative terms, the results concur in ability to define samples as positive or negative for receptor content. One of the parameters that most strongly influences accuracy of determination of receptor concentration is protein assay. The evaluation of several lyophilized preparations at scalar concentrations permitted identification, by linear regression, for each laboratory of the systematic and non-systematic variables. More comparable results will be forthcoming when a standardized methodology program has been fully adopted.
Authors have passed from a combined clinical and radioisotopic analysis to an integrated polyinstrumental approach by adding thermography and above all echography. In order to achieve the purpose Authors have confronted in retrospective a "clinico-radioisotopic group" of 103 cases, from 1965 to 1975, and an "integrated polyinstrumental group" of 53 cases, since 1976. Comparing the "clinico-radioisotopic method" with "polyinstrumental approach" the main results could be summarized as follows: the diagnostic specificity improved in benign lesions from 77% to 96%, however in malignant lesions it remained about the same (63%). Considering these results the Authors have subdivided thyroid nodules, mainly based on echography, in two distinct categories with the following orientation: I. Solitary Thyroid Nodule: a) definitely cystic -- demonstrated by echography; b) "cold" -- by conventional scintygraphy; c) "negative" -- by thermography; d) non uptake of tumor seeking radiopharmaceutical. The control, therapy and surveilance of these cases should be limited to needle aspiration of the cystic cavity followed, of course, by citologic examination. This aspirations is both diagnostic and possibly therapeutic. II. Solitary Thyroid Nodule: a) definite solid -- echography; b) "cold" -- convential scintygraphy; c) "positive" --thermography (possibly "negative"); d) non uptake of tumor seeking radiopharmaceutical. Here the therapeutic orientation is clearly surgical.
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Amniotic fluid endothelin-1 (ET-1) levels were measured in 38 euploid and in 15 aneuploid pregnancies in the 17th gestational week. Varying distribution of the peptide levels was found in the two groups, with higher values in the pathological cases. Should this finding be confirmed in maternal blood, ET-1 could represent a further analyte to be used in prenatal screening for aneuploidy.
This article illustrates the two main methods for routine measurement of cytoplasmic estrogen receptor status in neoplastic biopsy. The first is the Dextran Coated Charcoal Technique (D.C.C. Assay) which is still the method of choice in the majority of clinical laboratories for its simplicity, reproducibility and low cost. The second is a more advanced technique based on the specific binding, enzymatically displayed, of commercially available antiestrogen monoclonal antibodies (Enzyme Immuno Assay - ABBOTT). The sui generis characteristics of endocrine sensitivity assessment on tumor tissues and the importance of decision-making connected with the assay justify rigorous quality assurance schemes. The quality control design proposed by the Italian Committee concerned the evaluation of several lyophilized preparations with scalar receptor content; this permits the identification through linear regression analysis of systematic and non-systematic errors. The Italian Committee has currently connected 50 labs from most regions of the country.