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Cell Calcium May 1990
Review
Topics: Animals; Calcium; Humans; Parathyroid Glands; Parathyroid Hormone; Second Messenger Systems
PubMed: 2194660
DOI: 10.1016/0143-4160(90)90035-s -
Biotechnic & Histochemistry : Official... Nov 2022Bone healing deficiencies are challenging for orthopedic practice. The use of stem cells with scaffolds to treat bone tissue losses currently is popular for promoting...
Bone healing deficiencies are challenging for orthopedic practice. The use of stem cells with scaffolds to treat bone tissue losses currently is popular for promoting regeneration of tissue. Programmable cells of monocytic origin (PCMO) may differentiate into three germ layers and may be a promising alternative treatment due to their stem cell-like properties. Parathyroid hormone (PTH) participates in bone metabolism. Intermittent administration of PTH promotes osteogenic activity of mesenchymal stem cdells (MSC). We investigated the osteogenic effects of continuous and intermittent administration of PTH on PCMO. Mononuclear cells were harvested from the peripheral blood of healthy donors. Isolated cells were cultured for six days in a de-differentiation medium. Indirect immunocytochemistry using anti-CD14, anti-CD45 and anti-CD90 primary antibodies, as well as electron microscopy were used to detect PCMO. PCMO then were cultured in an osteogenic differentiation medium supplemented with continuous or intermittent 50 ng/ml PTH. The PTH-free control group (CG), intermittent PTH treated group (IPG) and continuous PTH treated group (CPG) were cultured and assessed for their differentiation into osteogenic lineage cells by indirect immunocytochemistry using anti-collagen I, anti-osteonectin and anti-osteocalcin primary antibodies. Osteoblast-like cells obtained by continuous or intermittent PTH administration exhibited increased levels of collagen I, osteonectin and osteocalcin immunoreactivity. We found that continuous and intermittent PTH administration to PCMO enhanced their differentiation to osteogenic lineage cells and increased osteoblastic activity.
Topics: Osteogenesis; Parathyroid Hormone; Cell Differentiation; Osteoblasts; Stem Cells
PubMed: 35473476
DOI: 10.1080/10520295.2022.2049876 -
Biomedicine & Pharmacotherapy =... 2002Intraoperative quick parathyroid hormone (QPTH) assay is claimed to prevent failure during parathyroidectomy for hyperparathyroidism. The causes of operative failure... (Review)
Review
Intraoperative quick parathyroid hormone (QPTH) assay is claimed to prevent failure during parathyroidectomy for hyperparathyroidism. The causes of operative failure have included multiglandular disease, ectopic parathyroid glands, supernumerary parathyroid glands, errors in frozen section evaluations, and missed diagnosis. A QPTH assay has been recognized as a useful method of determining whether hyperfunctioning tissues have been completely excised. However, an intraoperative QPTH assay may fail to detect the presence of double parathyroid adenomas. Use of this assay in conjunction with preoperative and intraoperative localization studies has led to the advocacy of more directed cervical procedures, such as limited, video-assisted, and endoscopic parathyroidectomy.
Topics: Biological Assay; Humans; Hyperparathyroidism; Intraoperative Care; Parathyroid Hormone
PubMed: 12487246
DOI: 10.1016/s0753-3322(02)00260-3 -
Endokrynologia Polska 2011Most medical agents currently applied in osteoporosis therapy act by inhibiting bone resorption and reducing bone remodelling, i.e. they inhibit the process of bone mass... (Review)
Review
Most medical agents currently applied in osteoporosis therapy act by inhibiting bone resorption and reducing bone remodelling, i.e. they inhibit the process of bone mass loss by suppressing bone resorption processes. These drugs provide an ideal therapeutic option to prevent osteoporosis progression. They however have a rather limited usefulness when the disease has already reached its advanced stages with distinctive bone architecture lesions. The fracture risk reduction rate, achieved in the course of anti-resorptive therapy, is insufficient for patients with severe osteoporosis to stop the downward spiral of their quality of life (QoL) with a simultaneously increasing threat of premature death. The activity of the N-terminal fragment of 1-34 human parathormone (teriparatide - 1-34 rhPTH), a parathyroid hormone (PTH) analogue obtained via genetic engineering , is expressed by increased bone metabolism, while promoting new bone tissue formation by stimulating the activity of osteoblasts more than that of osteoclasts. The anabolic activity of PTH includes both its direct effect on the osteoblast cell line, and its indirect actions exerted via its regulatory effects on selected growth factors, e.g. IGF-1 or sclerostin. However, the molecular mechanisms responsible for the actual anabolic effects of PTH remain mostly still unclear. Clinical studies have demonstrated that therapeutic protocols with the application of PTH analogues provide an effective protection against all osteoporotic fracture types in post-menopausal women and in elderly men with advanced osteoporosis. Particular hopes are pinned on the possibility of applying PTH in the therapy of post-steroid osteoporosis, mainly to suppress bone formation, the most important pathological process in this regard. The relatively short therapy period with a PTH analogue (24 months) should then be replaced and continued by anti-resorptive treatment.
Topics: Bone Density; Bone Density Conservation Agents; Humans; Osteoporosis; Parathyroid Hormone; Randomized Controlled Trials as Topic; Severity of Illness Index; Teriparatide
PubMed: 22125020
DOI: No ID Found -
The Journal of Endocrinology Sep 1997While PTHrP acts as a hormone when it is produced in excess by certain cancers, and perhaps also in lactating women, the foetus, and lower vertebrates, it seems clear... (Review)
Review
While PTHrP acts as a hormone when it is produced in excess by certain cancers, and perhaps also in lactating women, the foetus, and lower vertebrates, it seems clear that PTHrP is an important paracrine regulator of several tissue-specific functions. Its roles in smooth muscle relaxation, placental calcium transport, and bone development are becoming firmly established. However, it is likely to be an important player in the control of cellular growth and differentiation, although much of our understanding of this role to date comes from indirect evidence. The next decade will be an exciting time in defining further both the hormonal and paracrine actions of PTHrP.
Topics: Animals; Bone and Bones; Cytokines; Embryonic and Fetal Development; Humans; Hyperparathyroidism; Muscle, Smooth, Vascular; Parathyroid Hormone; Parathyroid Hormone-Related Protein; Proteins
PubMed: 9379134
DOI: No ID Found -
Clinical Calcium Jan 2012Bone formation is the key for successful dental treatments including periodontal tissue regeneration osseointegration of implant placement in which new alveolar bone... (Review)
Review
Bone formation is the key for successful dental treatments including periodontal tissue regeneration osseointegration of implant placement in which new alveolar bone formation is mandatory. Parathyroid hormone (PTH) is a peptide hormone containing 84 amino acids. Accumulated results show that intermittent PTH administration increases bone mass. Accordingly, recombinant N-terminal fragment of human PTH (1-34) , Teriparatide, is used for the treatments of osteoporosis worldwide. It is, therefore, expected that PTH has the potential to be a new therapeutic intervention for oral diseases that require increased bone remodeling and new bone formation.
Topics: Adaptor Proteins, Signal Transducing; Animals; Bisphosphonate-Associated Osteonecrosis of the Jaw; Bone Density Conservation Agents; Bone Morphogenetic Proteins; Bone Remodeling; Dental Implants; Genetic Markers; Humans; Insulin-Like Growth Factor I; Osseointegration; Osteogenesis; Parathyroid Hormone; Stimulation, Chemical; Stomatognathic Diseases; Teriparatide; Wnt Signaling Pathway
PubMed: 22201102
DOI: No ID Found -
Seminars in Nephrology Mar 1994
Review
Topics: Animals; Gene Expression Regulation; Humans; Parathyroid Hormone; Protein Processing, Post-Translational; Transcription, Genetic
PubMed: 8177983
DOI: No ID Found -
Proceedings of the National Academy of... Mar 1972Biosynthesis of a precursor to bovine parathyroid hormone has been demonstrated in slices of parathyroid tissue incubated in vitro. The proparathyroid hormone is 15-20...
Biosynthesis of a precursor to bovine parathyroid hormone has been demonstrated in slices of parathyroid tissue incubated in vitro. The proparathyroid hormone is 15-20 amino acids larger than the bovine hormone, and has a molecular weight of about 11,500 as determined by polyacrylamide gel electrophoresis. Upon incubation of parathyroid slices with [(14)C]aminoacids, radioactivity is detected initially in the precursor. If incorporation of [(14)C]aminoacids is inhibited after a short incubation either by replacement of radioactive amino acids with unlabeled amino acids or by addition of puromycin, the amount of radioactivity in the precursor decreases, while the radioactivity in the hormone continues to increase. The precursor is bound by an antibody that is specific for parathyroid hormone, and its binding can be inhibited by addition of the hormone. Analysis of tryptic digests indicates that the precursor and the hormone have common tryptic peptides, and that there are at least two additional peptides in the precursor.
Topics: Amino Acids; Animals; Carbon Isotopes; Cattle; Chromatography, Paper; Electrophoresis, Starch Gel; Kinetics; Parathyroid Glands; Parathyroid Hormone; Proteins; Radioimmunoassay; Threonine; Tritium; Trypsin
PubMed: 4501579
DOI: 10.1073/pnas.69.3.643 -
The American Journal of Medicine May 1971
Review
Topics: Animals; Biological Transport; Bone and Bones; Calcium; Cyclic AMP; Humans; Hyperparathyroidism; Parathyroid Hormone; Phosphates; Rickets
PubMed: 4325017
DOI: 10.1016/0002-9343(71)90112-4 -
The American Journal of Medicine Jun 1974
Review
Topics: Amino Acid Sequence; Animals; Binding Sites, Antibody; Cattle; Chromatography, Gel; Dogs; Epitopes; Humans; Hydrolysis; Iodine Radioisotopes; Kinetics; Metabolic Clearance Rate; Parathyroid Hormone; Peptide Fragments; Radioimmunoassay; Structure-Activity Relationship
PubMed: 4133938
DOI: 10.1016/0002-9343(74)90805-5