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Biomedical subjects

G Giovannini

Publications and source records attributed to G Giovannini.

At least 37 records · Page 2Linked to original sources
PubMed1989

Characterization of laboratory working standard for quality control of immunometric and radiometric estrogen receptor assays. Clinical evaluation on breast cancer biopsies. Italian Committee for Hormone Receptor Assays Standardization.

The objective of the study was to characterize a low-cost and reliable working standard material for quality control of estrogen receptor (ER) determination with dextran-coated charcoal (DCC) and enzyme immunoassay (EIA) methods. Human fibromatous uterine lyophilized cytosol demonstrated good characteristics of stability and applicability for this purpose. Eleven laboratories participated in the intralaboratory and interlaboratory quality control study, and they achieved slightly higher coefficients of variation for ER-EIA (interlaboratory, 37.7%; intralaboratory, 22.9%) than for ER-DCC (interlaboratory, 24.2%; intralaboratory, 15.7%). There was an excellent correlation between ER results with ER-EIA and ER-DCC for 268 breast cancer biopsies. Quality assurance for ER assays using DCC techniques and immunometric methods with monoclonal antibodies (ER-EIA) can be set up with this available material of human origin to satisfy the characteristics of both techniques and the species specificity of monoclonal antibodies.

Breast Neoplasms↗
PubMed1988

Amiodarone and thyroid status in refractory arrhythmias.

Out of 20 subjects selected for refractory arrhythmias, amiodarone therapy (200 mg/day) was efficacious in 85%. No statistically significant variations in electrocardiographic parameters (QTc) were observed; similarly, there was little evidence of side effects 1 year after initiation of treatment. These results were most likely due to the low daily dosage administered. We observed: 1) a significant increase in rT3 levels; 2) a decrease in TT3; 3) a uniform homeostasis of free fraction (FT3;FT4) These effects are all characteristic patterns of a "Low T3 Syndrome". The dosage of circulating amiodarone in 6 patients with borderline hormonal status (3 hyper- and 3 hypothyroidism) was not found to be an efficacious test for therapeutic monitoring. Identification of a statistically significant linear regression relationship between cumulative dose of amiodarone and rT3 levels may be a useful test in clinical practise for establishing more appropriate therapeutic dosages. Furthermore, it provides a guideline for threshold levels (maximum rT3 = 100-110 ng/dl) which are in close association with several side effects.

Adult↗
PubMed1987

Testis cytological structure, plasma sex steroids, and gonad cytosol free steroid receptors of heterologous gonadotropin (hCG)-stimulated silver eel, Anguilla anguilla L.

Complete testicular maturation was induced in silver eels, kept at 24 degrees in fresh water, by a single injection of 1000 I.U. of heterologous gonadotropin (hCG). Each week, for 4 weeks, some eels were examined for testis structural pattern, plasma sex steroids, and gonad cytosol steroid receptors. The first effect of the hCG was on the tubular organization of the testis, followed by spermatogenesis. Plasma androgens were not detectable in the untreated eels, whereas a peak was detected a week after in those treated with the injection and afterward a decline. Plasma progesterone and estradiol showed a peak 2 weeks after treatment. Untreated eel gonads showed a high content of cytosolic free estradiol receptors which disappeared in the hCG-treated ones, a peak of free progesterone receptors was found 1 week after injection. The results are discussed in relation to the differentiation and maturation of eels testes.

Anguilla↗
PubMed1985

Quality assurance for steroid receptor assay in human breast cancer: six years experience of the Italian Committee.

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.

Breast Neoplasms↗
PubMed1985

Quality control for estrogen and progesterone receptor assay in human breast cancer: the influence of computation methods on intra and interlaboratory variability.

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.

Breast Neoplasms↗
PubMed1985

[Changes in thyroid hormone status after injections of iodinated contrast media].

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.

Angiography↗
PubMed1984

Hormone receptors and breast cancer: correlations with clinical and histologic features.

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.

Adult↗
PubMed1983

Evaluation of some coagulation parameters in cerebral ischemia.

In order to investigate some aspects of blood coagulation and of platelet function in cerebral ischemia, 18 healthy subjects, 24 patients with previous cerebral infarction and 12 patients with transient ischemic attacks were studied. All patients were in a non-active state of the illness. In all subjects, platelet count, prothrombin time, activated partial thromboplastin time and determination of the fibrinogen concentration were performed as routine. All subjects were tested for platelet adhesiveness, circulating platelet aggregates, factor VIII coagulant (VIII C), factor VIII-related von Willebrand factor (VII RWF), factor VIII-related antigen (VII RAg), antithrombin III (AT III) concentration and activity and euglobulin clot lysis time. No significant difference between patients and controls was found in routine tests, platelet function, AT III concentration or activity. Plasma levels of VIII C, VIII RWF, VIII RAg were significantly increased in both patient groups. The VIII RAg/VIII C ratio was significantly increased only in patients with previous cerebral infarction. Euglobulin clot lysis time was significantly increased in both patient groups.

Adult↗
PubMed1982

[Protein assay for cellular receptors of steroids: a critical study of the technic with Coomassie-blue].

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.

Animals↗
PubMed1975

[Left bu;ndle branch block with right axial deviation. Clinic and electro-vectorcardiographic study (author's transl)].

Eleven patients whose ECG and VCG showed a left bundle branch block with right axial deviation (between + 90 degrees and + 150 degrees) were studied with clinical and radiological investigations. All of them had pathological abnormalities of cardiopulmonary apparatus and cardiac enlargement, but only one had congestive heart failure. The right axial deviation was due in one case to the vertical position of the heart in the chest and in three cases to conduction defects of the cardiac impulse through the left bundle branch. In the remaining cases the right axial deviation was dubious. The authors present and discuss all possible factors which could cause such deviation of QRS axis in the left bundle branch block.

Aged↗