Evidence is needed on the risks and benefits of combination therapy with levothyroxine (LT4)+liothyronine (LT3) for the treatment of hypothyroidism. We performed a randomized, double-blind placebo-controlled study to assess the effects of LT4+LT3 therapy versus LT4+placebo in a homogeneous group of athyreotic patients, without cardiovascular risk factors during long-term replacement monotherapy with LT4. The primary objective of the study was to assess the effects of combination LT4+LT3 therapy on heart rate, cardiac rhythm, and sensitive cardiovascular parameters of cardiac morphology and function by means of electrocardiography and Doppler echocardiography.
View Article and Find Full Text PDFGraves' orbitopathy (GO) is the main extrathyroidal manifestation of Graves' disease (GD). Diabetes mellitus (DM) has been reported to be a risk factor in patients with GO. Moreover, GO can be more frequent and severe in type 2 diabetes patients.
View Article and Find Full Text PDFThe management of indeterminate thyroid lesions is controversial. The American Thyroid Association (ATA) guidelines suggest a conservative approach for low risk indeterminate thyroid lesions (TIR3A). We report a clinical case of a young girl who had TIR3A in a thyroid nodule located in the isthmus.
View Article and Find Full Text PDFRadioiodine (RAI) therapy for treatment of differentiated thyroid cancer (DTC) requires high serum thyroid-stimulating hormone (TSH) levels to induce a sufficient iodine uptake within thyroid cells. Recombinant Human TSH (rhTSH) induces an exogenous TSH level increase without LT4 withdrawal. It is a valid alternative to LT4-withdrawal (LT4-W) to achieve the TSH levels required for RAI therapy.
View Article and Find Full Text PDFBackground: The role of thyrotropin (TSH) on the cardiovascular system has been poorly investigated. It is unknown whether the changes in the vasculature associated with thyroid diseases result from altered thyroid hormone action or whether they are a consequence of a direct effect of TSH on endothelial cells. The present study was designed to evaluate the endothelial response of coronary flow to TSH in patients with differentiated thyroid cancer (DTC) without cardiovascular risk factors.
View Article and Find Full Text PDFIt has been demonstrated that the third component of complement (C3)(1) and its peptides increase normal and tumour cell proliferation. However, the signal cascade responsible for this phenomenon is still unknown. In this study, we elucidate some of the mechanisms involved in the signalling of C3 stimulation of cell proliferation.
View Article and Find Full Text PDFIn this investigation we show that the death-inducing signaling complex (DISC) associates with glycosphingolipid-enriched microdomains (GEM) upon CD95/Fas engagement. We primarily analyzed the ganglioside pattern and composition of GEM after triggering through CD95/Fas and observed that GM3 is the main ganglioside constituent of GEM. Stimulation with anti-CD95/Fas did not cause translocation of gangliosides within or from the GEM fraction.
View Article and Find Full Text PDFIn this report we demonstrated that cellular prion protein is strictly associated with gangliosides in microdomains of neural and lymphocytic cells. We preliminarily investigated the protein distribution on the plasma membrane of human neuroblastoma cells, revealing the presence of large clusters. In order to evaluate its possible role in tyrosine signaling pathway triggered by GEM, we analyzed PrPc presence in microdomains and its association with gangliosides, using cholera toxin as a marker of GEM in neuroblastoma cells and anti-GM3 MoAb for identification of GEM in lymphoblastoid cells.
View Article and Find Full Text PDFIn this study we analyzed the signaling pathway triggered by GM3 in lymphoblastoid T-cells. In these cells, GM3 induced cPLA2 activation, arachidonic acid release, and PKC-delta translocation. In order to clarify the upstream molecular signals triggered by GM3, we analyzed the activation of extracellular signal-regulated kinase (ERK)s, a downstream effector of Ras-regulated cytoplasmic kinase cascade.
View Article and Find Full Text PDFRecent evidence demonstrated that T cell activation leads to the redistribution of membrane and intracellular kinase-rich raft microdomains at the site of TCR engagement. In this investigation we demonstrated by high performance thin layer chromatography, gas chromatographic, and mass spectrometric analyses that GM3 is the main ganglioside constituent of these microdomains in human lymphocytes. Then we analyzed GM3 distribution and its interaction with the phosphorylation protein Zap-70.
View Article and Find Full Text PDFThe aim of this study was to further elucidate our previous observation on molecular interaction of GM3, CD4 and p56Ick in microdomains of human peripheral blood lymphocytes (PBL). We analyzed GM3 distribution by immunoelectron microscopy and the association between GM3 and CD4-p56Ick complex by scanning confocal microscopy and co-immunoprecipitation experiments. Scanning confocal microscopy analysis showed an uneven signal distribution of GM3 molecules over the surface of human lymphocytes.
View Article and Find Full Text PDFWe report that prosaposin treatment induced extracellular signal-regulated kinases (ERKs) and sphingosine kinase activity, increased DNA synthesis, and prevented cell apoptosis. Prosaposin treatment induced pheochromocytoma cells (PC12) to enter the S phase of the cell cycle; this effect was inhibited by the MEK inhibitor PD98059, indicating that prosaposin-induced ERK phosphorylation is required for stimulation of DNA synthesis. The prosaposin effect was also inhibited by pertussis toxin, indicating that the prosaposin receptor is a G-protein-coupled receptor.
View Article and Find Full Text PDFThis study provides evidence that cardiolipin (CL) molecules are expressed on the surface of apoptotic cells and are recognized by antiphospholipid antibodies, purified from patients with the antiphospholipid antibody syndrome (APS). CL expression on cell surface was demonstrated by high performance thin layer chromatography analysis of phospholipids from plasma membrane purified fractions and by the positive staining with the CL-specific dye nonyl-acridine orange. This finding was complemented with the observation that aCL IgG purified from patients with APS bind to the surface of apoptotic cells.
View Article and Find Full Text PDFAIDS Res Hum Retroviruses
October 2000
This study was undertaken to analyze the role of disialoganglioside GD3 in HIV infection and disease progression. We report here the results obtained by both ex vivo and in vitro experiments on (1) surface and cytoplasmic expression and distribution of GD3 in HIV-infected cells, (2) the presence of anti-GD3 antibodies in sera of patients with HIV infection in various stages of the disease, and (3) the association of GD3 expression with HIV-related apoptotic events. GD3 expression was determined by high-performance thin-layer chromatography (HPTLC) and lipid-bound sialic acid and by static and flow cytometric analyses in peripheral blood lymphocytes from 22 AIDS patients, 20 anti-HIV Ab(+) asymptomatic subjects, and 25 healthy donors.
View Article and Find Full Text PDFC3 production, release and CRs expression during the neutrophilic differentiation of a murine non tumorigenic cell line is investigated. The murine non tumorigenic cell line 32DCl3(G) which undergoes terminal differentiation into polymorphonuclear granulocytes when cultured in presence of G-CSF was selected as a suitable in vitro model for this study. The results show that as the cells progress into the differentiation program, levels of C3 mRNA increase, accompanied by increased C3 production.
View Article and Find Full Text PDFEur J Gastroenterol Hepatol
August 1999
Objective: To evaluate the release of interleukin-6 (IL-6) by oesophageal mucosa and to establish the serum levels of IL-6 and C-reactive protein (CRP), and plasma fibrinogen in children with reflux oesophagitis.
Design: In a prospective study, IL-6 release by tissue fragments obtained from oesophageal biopsies was determined and serum IL-6 and CRP as well as plasma fibrinogen were analysed.
Methods: The study population comprised ten children with reflux oesophagitis, diagnosed on the basis of 24 h oesophageal pH monitoring and endoscopy with biopsies.
Immunobiology
February 1999
C3 molecules from normal murine serum are mainly bound to Lewis lung carcinoma cells (3LL) that do not express CRs, mainly through covalent binding as determined by the appearance of bands stained with anti-C3 and larger than 190 kD in immunoblots of proteins in whole cell extracts. Methylamine-treated, or zymosan-treated normal mouse serum, heat inactivated, or EDTA-treated murine serum resulted in low C3 deposition on 3LL cells, as indicated by fluorescence tests and immunoblotting. Cytofluorimetric studies showed that C3 molecules bound to 3LL cells were internalized in a time- and temperature-dependent process.
View Article and Find Full Text PDFIn this report the molecular mechanism(s) involved in the rapid and selective endocytosis of cell surface glycoprotein CD4 induced by exogenous monosialoganglioside GM3 in human peripheral blood lymphocytes have been investigated. Inhibition of the GM3-induced CD4 down-modulation was observed in the presence of specific protein kinase C (PKC) inhibitors. Scanning confocal microscopy revealed the translocation and clustering on the cell surface of PKC isozymes delta and theta (more evidently than alpha and beta) after GM3 treatment, suggesting the involvement of these isozymes in the ganglioside-induced CD4 down-modulation.
View Article and Find Full Text PDFProsaposin, the precursor of saposins A, B, C, and D, was recently identified as a neurotrophic factor in vitro as well as in vivo. Its neurotrophic activity has been localized to a linear 12-amino acid sequence located in the NH2-terminal portion of the saposin C domain. In this study, we show the colocalization of prosaposin and ganglioside GM3 on NS20Y cell plasma membrane by scanning confocal microscopy.
View Article and Find Full Text PDFJ Pediatr Gastroenterol Nutr
February 1998
Background: Prostaglandin E2 (PGE2) is said to be both protective and detrimental for esophageal mucosal integrity. Nitric oxide (NO) controls several esophageal neuromuscular functions, including relaxation of the lower esophageal sphincter. The purpose of this study was to verify PGE2 and NO levels in esophageal mucosa of children with reflux esophagitis.
View Article and Find Full Text PDFThe present study was undertaken to evaluate the effects of the glucocorticoid hormones betamethasone and hydrocortisone, and of progesterone on the relative production of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) by explants of human fetal membranes at term gestation in the absence of labor. Tissues (n = 7) were incubated either in the presence or in the absence of the above mentioned hormones. PGE2 and LTB4 were measured in culture medium by radioimmunoassays.
View Article and Find Full Text PDFGangliosides may play functional roles in platelet physiology, therefore this study has been designed to evaluate whether changes in ganglioside composition may occur as a consequence of platelet activation. The results obtained indicate that lactosylceramide and GM3 are the major glycosphingolipids of human platelets. The lipid-bound sialic acid (LBSA) content was 1.
View Article and Find Full Text PDFEur J Obstet Gynecol Reprod Biol
November 1996
Objectives: To examine the in vitro release of nitric oxide (NO) by human fetal membranes at term gestation and to investigate whether NO could stimulate prostaglandin E2 (PGE2) release by these tissues.
Study Design: Explants of fetal membranes (n = 17) were incubated either in the presence of sodium nitroprusside (NP), or L-Arginine (L-Arg), or bacterial lipopolysaccharide (LPS), or in the absence of the above substances (controls). NO and PGE2 concentrations in culture medium were assayed by the Griess reaction and radioimmunoassay, respectively.