Efficiency of doxorubicin handling by isolated hepatocytes is a valuable indicator for restored cell function.

Pig liver is a possible source of hepatocytes for extracorporeal bio-artificial liver devices. In order to evaluate recovered hepatocyte function following enzymatic isolation, we developed a cytochemical method that is based on the capacity of hepatocytes to sequester the anthracycline antitumour drug doxorubicin within intracellular acidic compartments. Doxorubicin is a naturally fluorescent molecule.

Thyroglobulin regulates follicular function and heterogeneity by suppressing thyroid-specific gene expression.

Thyroglobulin (TG) is the primary synthetic product of the thyroid and the macromolecular precursor of thyroid hormones. TG synthesis, iodination, storage in follicles, and lysosomal degradation can each modulate thyroid hormone formation and secretion into the circulation. Thyrotropin (TSH), via its receptor (the TSHR), increases thyroid hormone levels by upregulating expression of the sodium iodide symporter (NIS), thyroid peroxidase (TPO), and TG genes.

In vivo expression of thyroid transcription factor-1 RNA and its relation to thyroid function and follicular heterogeneity: identification of follicular thyroglobulin as a feedback suppressor of thyroid transcription factor-1 RNA levels and thyroglobulin synthesis.

We used in situ hybridization to evaluate thyroid transcription factor-1 (TTF-1) RNA expression in individual follicles and related this to thyroglobulin (Tg) synthesis in vivo, as estimated by immunohistochemical analysis. We studied the thyroids of Wistar rats treated with thyroxine (T4) or propylthiouracil (PTU), each of which modulates TSH levels, but affects follicular function and Tg accumulation in the follicular lumen very differently. We show that TTF-1 RNA levels in vivo correlate directly with an increase in the cytoplasmic accumulation of Tg within the cells of individual follicles.

Cell cycle synchronization of FRTL5 cells. A physiological model system.

We describe a "physiological" cell cycle synchronization model system. FRTL5 cells, TSH-dependent for proliferation, were starved from TSH. The cell cycle phases and the expression of markers associated to different cycle phases were evaluated.

Thyroid transcription factor 1 is calcium modulated and coordinately regulates genes involved in calcium homeostasis in C cells.

Thyroid transcription factor 1 (TTF-1) was identified for its critical role in thyroid-specific gene expression; its level in the thyroid is regulated by thyrotropin-increased cyclic AMP levels. TTF-1 was subsequently found in lung tissue, where it regulates surfactant expression, and in certain neural tissues, where its function is unknown. Ligands or signals regulating TTF-1 levels in lung or neural tissue are unknown.

Autoregulation of thyroid-specific gene transcription by thyroglobulin.

Thyroglobulin (TG), the primary synthetic product of the thyroid, is the macromolecular precursor of thyroid hormones. TG synthesis, iodination, storage in follicles, and degradation control thyroid hormone formation and secretion into the circulation. Thyrotropin (TSH), via its receptor (TSHR), increases thyroid hormone levels by up-regulating expression of the sodium iodide symporter (NIS), thyroid peroxidase (TPO), and TG genes.

Regulation of major histocompatibility (MHC) class II human leukocyte antigen-DR alpha gene expression in thyrocytes by single strand binding protein-1, a transcription factor that also regulates thyrotropin receptor and MHC class I gene expression.

The single strand binding protein (SSBP-1) is a positive regulator of TSH receptor gene expression and binds to an element with a GXXXXG motif. The S box of the mouse major histocompatibility class II gene has multiple GXXXXG motifs and can also bind SSBP-1. The S box is one of four highly conserved elements on the 5'-flanking region of class II genes that are necessary for interferon-gamma (IFNgamma) to overcome the normally suppressed state of the gene and induce aberrant class II expression.

In vitro cultured stromal cells from human tonsils display a distinct phenotype and induce B cell adhesion and proliferation.

Peripheral lymphoid tissues contain a fibroblastic cell type referred to as stromal cells or reticulum cells which interact with lymphocytes as part of the lymphoid microenvironment. After isolation from human tonsils and expansion in vitro we analyzed the surface phenotype, extracellular matrix components, cytoskeletal products, cytokine production, binding and functional interaction with B lymphocytes of in vitro cultured stromal cells (HTSC) both in resting condition and after activation with tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. Our results show that HTSC do not express specific myeloid, lymphoid, endothelial or epithelial markers.

Effect of marrow processing on hematopoietic cell recovery in bone marrow harvests: focus on filtration.

Bone marrow processing requires a first step of filtration to remove small clots, bone fragments, fat cells and fibrin followed by centrifugation to separate mononuclear cells (MNC). These procedures cause a significant loss of cells potentially including hematopoietic stem cells (HSC). We therefore analyzed the cell recovery and phenotype of various fractions (whole marrow; filtered marrow; MNC collected after centrifugation; bone marrow fragments trapped by filtration) of bone marrow harvests (BMH) from patients with different hematological malignancies undergoing autologous bone marrow transplantation.

Effect of stromal cells from human lymph nodes on the growth of osteosarcoma cell lines.

We investigated whether stromal cells obtained from human tonsils could interact and modulate the proliferation of the osteosarcoma cell in order to determine why lymph node metastases usually have a low incidence and remain occult using routine examinations. The effects of the supernatant of resting or activated stromal cells were analysed on osteoblastic cell proliferation of three different cell lines (HOS, U2, OS, MG-63). Only the proliferation of MG-63 was significantly inhibited.