The aim of this study was to evaluate thyroid peroxidase (TPO) mRNA expression in peripheral blood of patients with benign and malignant thyroid disease. Included were 120 thyroid cancer patients, 85 patients with goitre or Graves' disease (GD) and 54 healthy volunteers. TPO mRNA expression was analysed in peripheral blood by nested RT-PCR. In cancer patients, RT-PCR results were compared with ...

Radiation-induced pancytopenia proved to be a suitable model system in mice and rhesus monkeys for studying thrombopoietin (TPO) target cell range and efficacy. TPO was highly effective in rhesus monkeys exposed to the mid-lethal dose of 5 Gy (300 kV x-rays) TBI, a model in which it alleviated thrombocytopenia, promoted red cell reconstitution, accelerated reconstitution of immature CD34+ bone ...

In this study, we demonstrate that human umbilical cord vein-derived endothelial cells (HUVECs) expressed c-Mpl, the thrombopoietin (TPO) receptor, and that TPO activates HUVECs in vitro, as indicated by directional migration, synthesis of 1-alkyl-/1-acyl-platelet-activating factor (PAF) and interleukin-8 (IL-8), and phosphorylation of the signal transducers and activators of transcription (STA...

Tissue Po(2) (tPo(2)) reflects the balance between local O(2) supply and demand and, thus, could be a useful monitoring modality. However, the consistency and amplitude of the tPo(2) response in different organs during different cardiorespiratory insults is unknown. Therefore, we investigated the effects of endotoxemia, hemorrhage, and hypoxemia on tPo(2) measured in deep and peripheral organ b...

The mechanisms that regulate circulating levels of thrombopoietin (Tpo) are incompletely understood. According to one favored model, the rate of Tpo synthesis is constant, whereas the serum concentration of free Tpo is modulated through binding to c-Mpl receptor expressed on blood platelets. Additionally, a role for c-Mpl expressed on megakaryocytes is suggested, particularly by the observation...

Evidence exists that autoimmune thyroiditis is present in a high percentage of fibromyalgia (FM) and associated with the presence of typical symptoms of FM. However, the role of thyroperoxidase antibody (TPO Ab) in the manifestation of FM is still unclear. The goal of this study was to investigate the prevalence of positive TPO Ab in euthyroid FM patients, and whether TPO Ab positivity is assoc...

In this study we describe a novel mutation of the thyroid peroxidase (TPO) gene that resulted in a total iodide organification defect. TPO activity and thyroxine formation in thyroglobulin in the thyroid gland of the patient were below the limits of detection. However, TPO mRNA was detectable at a similar size and concentration as compared with normal thyroid tissues when measured by Northern b...

A heterogeneity in the molecular weight (Mr) of thrombopoietin (TPO) has been reported. We found several thrombin cleavage sites in human, rat, murine, and canine TPOs, and also found that human TPO undergoes selective proteolysis by thrombin. Recombinant human TPO (rhTPO) was incubated with human platelets in the presence of calcium ions to allow the generation of thrombin, and was cleaved int...

Myelofibrosis (MF) is characterized by hyperactivation of thrombopoietin (TPO) signaling, which induces a RPS14 deficiency that de-regulates GATA1 in megakaryocytes by hampering its mRNA translation. As mice carrying the hypomorphic Gata1low mutation, which reduces the levels of Gata1 mRNA in megakaryocytes, develop MF, we investigated whether the TPO axis is hyperactive in this model. Gata1low...

OBJECTIVE Thyroid peroxidase (TPO) deficiency is one of the causes of thyroid dyshormonogenesis, because TPO plays a key role in thyroid hormone biosynthesis. To determine the frequency and pattern of TPO abnormalities, we have been screening TPO genes of patients with congenital goitrous hypothyroidism. SUBJECTS AND METHODS TPO genes of a patient with congenital goitrous hypothyroidism and h...