PubMed Health⌕ Search

Biomedical subjects

M Scarlattini

Publications and source records attributed to M Scarlattini.

9 recordsLinked to original sources
PubMed2004

Erythrocyte Na/K-ATPase is increased in subjects with subclinical hypothyroidism.

OBJECTIVE: In erythrocytes of patients with overt hyperthyroidism, the number of ouabain-binding sites and the activity of the Na(+)/K(+)-ATPase have been demonstrated to be decreased, whereas the opposite is true in patients with overt hypothyroidism. No information has been reported on the status of the Na(+)/K(+)-ATPase in subclinically hypothyroid (Sub Hypo) patients. DESIGN: We investigated the number of ouabain-binding sites and Na(+)/K(+)-ATPase activity in erythrocytes of chronic Sub Hypo subjects. PATIENTS AND METHODS: We measured (3)H-ouabain-binding sites in erythrocytes from 15 patients with subclinical hypothyroidism, and compared with those found in 17 normal subjects (N), seven with overt hypothyroidism (Hypo) and 10 with overt hyperthyroidism (Hyper). The activity of the sodium pump was assessed by measuring ouabain-sensitive (86)Rb uptake in a subpopulation of the same groups. RESULTS: The number of ouabain-binding sites in Sub Hypo patients (252 +/- 17; mean +/- SEM) was significantly higher (P < 0.02) than in Hyper (135 +/- 12) and N (203 +/- 10) groups, whereas it was not significant different from Hypo (293 +/- 31). There was a positive correlation between the number of ouabain-binding sites and TSH concentrations (P < 0.002) when Sub Hypo and N groups were considered together. There was a negative correlation between the number of ouabain-binding sites and free thyroxine (FT4; P < 0.0001) and free triiodothyronine (FT3) concentrations (P < 0.001) when all subjects were considered. Ouabain-sensitive (86)Rb uptake (picomoles (86)Rb/h 10(6) cells) in Sub Hypo was significantly higher (4.2 +/- 0.5) when compared with N (2.5 +/- 0.2, P < 0.01) and Hyper (2.5 +/- 0.5, P < 0.02). CONCLUSIONS: Erythrocytes of subclinically hypothyroid patients show a significant increase in the number of ouabain-binding sites and in ouabain-sensitive (86)Rb uptake. The state of erythrocyte Na(+)/K(+)-ATPase may therefore represent a biochemical marker of subclinical hypothyroidism.

Adult↗
PubMed2001

Hyperthyroidism is associated with lengthening of ventricular repolarization.

OBJECTIVE: Lengthened ventricular repolarization, as assessed by the QT interval on electrocardiogram (ECG), can predispose to an increased risk of cardiac dysrhythmias; no data are available on QT corrected for heart rate (QTc) in hyperthyroidism in vivo. DESIGN: QT and RR intervals from 24 h ambulatory ECG Holter recording were measured in patients with hyperthyroidism and again following pharmacological achievement of stable euthyroidism for at least 2 months. PATIENTS: We enrolled a total of 16 hyperthyroid patients with Graves' disease, six males and 10 females (mean age 47 +/- 4 years, mean +/- SEM); 13 healthy age- and sex-matched subjects were utilized as a control group. MEASUREMENTS: The QT analysis was carried out by a computerized algorithm (QTc was corrected by the heart rate by Bazett's formula). Serum total T4, total T3, free T4, free T3 and TSH concentrations were measured by a fully automated immunoenzymometric assay; plasma norepinephrine by automatized high-pressure liquid chromatography, potassium and chloride by a potentiometric method, magnesium and calcium by a colourimetric method. RESULTS: The 24-h average QTc in the hyperthyroid patients was significantly prolonged compared to controls (458 +/- 7 vs. 431 +/- 6 ms, P = 0.01) and it returned to normal after treatment of thyrotoxicosis (432 +/- 6 ms, P < 0.05 vs. time H, NS vs. controls). QTc positively correlated with FT3 (r = 0.63, P < 0.001) and with FT4 (r = 0.481, P < 0.02). Conversely, QTc did not correlate with plasma basal norepinephrine levels, nor with electrolytes. CONCLUSIONS: Hyperthyroidism is associated with prolonged QTc that normalizes once the patient becomes euthyroid. The strong positive correlation between FT3 and QTc supports the hypothesis of an important role of thyroid hormone on modulation of QTc lengthening.

Adrenergic beta-Antagonists↗
PubMed1996

Progress report of an external quality assessment scheme for cyclosporine assay.

Beginning in 1987, an external quality assessment (EQA) scheme for cyclosporine (CsA) assay was organized by our Institute and supported by National Research Council (CNR); in 1991, the CNR EQA joined the French CsA interlaboratory program organized by Service de Radiopharmacie et Radioanalyse, University of Lyon. During the last 2 years (1993 and 1994 cycles), > 170 laboratories (from seven European countries) participated in this survey, assaying 44 control samples prepared from pooled blood of heart- and renal-transplant patients; normal pools added with known amounts of CsA were also distributed. During the whole EQA period, a trend toward the use of specific and nonisotopic techniques has been observed. In 1994, 91% of the collected results have been produced by specific methods [high-pressure liquid chromatography (HPLC) or specific immunoassays developed to assay the native molecule of CsA without its metabolites];in the same cycle, the fully automated techniques [TDx, fluorescence polarization immunoassay (FPIA), and enzyme-multiplied immunoassay (EMIT)] accounted for 73% of total results. CsA concentration measured by monoclonal specific immunoassays [(TDx FPIA, radioimmunoassay (RIA) Cyclo-Trac, and EMIT] was well correlated with those from HPLC (r = 0.99-1.00); results from EMIT were very close to those from HPLC, whereas results from RIA Cyclo-Trac and TDx were slightly overestimated (10-20%). Nonspecific methods (TDx polyclonal and nonspecific RIA Cyclo-Trac) measured CsA concentrations 3-4 times higher than those found by HPLC. The cross-reactivity of CsA metabolites in specific immunoassays was estimated from data of patients' samples and spiked samples; an interference of 6% in RIA Cyclo-Trac, 7% in EMIT, and 26% in TDx FPIA was found. The precision coefficient of variation (CV% between laboratory and between assay) of the methods observed in the 1994 EQA cycle was 9.5 for TDx polyclonal FPIA, 10.4 for TDx monoclonal FPIA, 10.5 for EMIT, 10.6 for RIA specific Cyclo-Trac, 14.2 for RIA nonspecific Cyclo-Trac, and 15.2 for HPLC.

Antibodies, Monoclonal↗
PubMed1993

Performance of a fully automated fluorometric enzyme immunoassay for serum myoglobin measurement.

An automated fluorometric enzyme immunoassay system for the determination of serum myoglobin has been recently developed. This method is based on the sandwich immunoassay and uses two mouse monoclonal antimyoglobin antibodies; the first one is complexed onto glass fiber paper and the second is conjugated to an enzyme alkaline phosphatase which reacts with the substrate 4-methylumbelliferyl phosphate to generate a fluorescent product. Using a dedicated automated apparatus the time to the first result is eight minutes, with additional values being produced at one-minute intervals (about 50 samples/hour). We compared the analytical performance of this fluorometric enzyme immunoassay with that of a RIA set up in our laboratory for the routine assay of serum myoglobin. The automated fluorometric enzyme immunoassay showed lower between-assay variability (CV = 4.7% vs 13.8%) and higher sensitivity (0.3 ng/mL vs 7.2 ng/mL) than the manual RIA. Moreover, the two immunoassays gave similar results when serum samples of normal subjects and patients with coronary artery disease with or without acute myocardial infarction (AMI) were assayed (fluorometric immunoassay = -0.7 + 0.851 RIA, r = 0.991, n = 137). In conclusion, the automated fluorometric enzyme immunoassay tested in the present study produces reliable clinical results with a rapid turnaround time and therefore can be recommended for use in the early detection of AMI in a laboratory of Coronary Care Unit.

Evaluation Studies as Topic↗
PubMed1991

Immunologic detection of endothelial cells in human whole blood.

In this report we show that human endothelial cells (EC) can be detected in circulating blood by means of the EC-specific monoclonal antibody (MoAb) designated as CLB-HEC 19 and expressed quantitatively as number of cells per milliliter of whole blood. We first developed a method that was able to recover cultured human EC added to whole blood by Percoll density gradient centrifugation. The final recovery of the EC was 91.6% (SE = 0.65%). The EC were identified in the gradient subfractions by indirect immunofluorescence with the MoAb CLB-HEC 19. This method was then applied to the separation and characterization of EC or EC remnants from the whole arterial and venous blood taken from two groups of patients subjected to heart catheterization. Firstly, a preliminary blood screening of random samples was performed in a group of eight patients (group I) using a scoring evaluation for the presence of EC and the results were expressed as positivity index. Secondly, the complete blood screening of a group of ten patients (group II) was performed for the detection of immunofluorescent cells and the results were expressed as number of EC per milliliter of whole blood. Our results show in both group I and II a significant presence of EC in the blood after catheterization compared with their basal values. The minimal detectable concentration of EC was 0.06 cells/mL (SE = 0.057) of whole blood. We consider this technique as a suitable clinical test for the detection of EC injury in cardiovascular pathology.

Antibodies, Monoclonal↗
PubMed1989

Superoxide production by human umbilical vein endothelial cells in an anoxia-reoxygenation model.

Ischaemia/reperfusion of cardiac tissue has been claimed to be associated with the production of oxygen free radicals, which can contribute to severe membrane damage and tissue injury. We investigated the effects of anoxia/reoxygenation treatment on superoxide radical production in an in vitro system consisting of preconfluent and confluent human endothelial cell monolayers. The influence of varying the anoxia and reoxygenation phases on superoxide production was studied. As a test of cytotoxicity, the release of the cytosolic enzyme lactate dehydrogenase in the culture medium was measured before and at 0, 24 and 48 h after anoxia-reoxygenation. Cellular damage was monitored by microscopic examination of the cultures during and after the experiments and by the expression of the von Willebrand protein and of the membrane glycoprotein IIa by indirect immunofluorescence with specific monoclonal antibodies. Our results show that the endothelial cells subjected to anoxia-reoxygenation release superoxide anions, as revealed by superoxide dismutase inhibitable cytochrome C reduction. Free radical production is dependent on cell confluent or preconfluent state and on both anoxia and reoxygenation duration. Free radical release does not seem to be accompanied by manifest cellular alteration.

Antibodies, Monoclonal↗