dihydrotachysterol and Bone-Diseases

Topics: Bone and Bones; Bone Diseases; Calcium; Cholecalciferol; Dihydrotachysterol; Homeostasis; Intestinal Absorption; Kidney; Kidney Failure, Chronic; Uremia; Vitamin D

The use of calcitriol in the treatment of uremic hyperparathyroidism and renal osteodystrophy is limited in many patients by hypercalcemic side-effects. New less calcemic analogues of calcitriol are being developed, and some are under clinical evaluation. To investigate whether these compounds possess important differences in their action on bone cells, we have studied their effects [with and without parathyroid hormone (PTH)] on the release and synthesis of the resorptive osteotropic cytokine, interleukin-6 (IL-6).. MG 63 and SaOS-2 human osteoblastic cell lines were cultured for 6 or 24 hours in media containing calcitriol, the sterols of interest, or 1-34 synthetic PTH. IL-6 release was assayed by commercially available enzyme-linked immunosorbent assay. IL-6 mRNA levels were assessed by reverse transcriptase-polymerase chain reaction.. We found that calcitriol and paricalcitol behaved in a similar fashion, resulting in increased IL-6 release only at higher concentrations (10(-7) to 10(-9) M). In contrast, 22-oxacalcitriol and 1,25-dihydroxydihydrotachysterol2 stimulated release to a similar extent but at concentrations three to four orders of magnitude lower (10(-11) to 10(-13) M), despite being less potent as suppressers of parathyroid function than calcitriol. Studies of IL-6 mRNA showed a similar pattern of concentration and cell line-dependent transcription.. Compounds stimulating IL-6 release at concentrations achievable during the treatment of uremic hyperparathyroidism might favor continuing linked bone formation and resorption and thereby avoid adynamic bone disease while still allowing profound suppression of PTH.

Topics: Bone Diseases; Calcitriol; Cell Line; Dihydrotachysterol; Ergocalciferols; Humans; Interleukin-1; Osteoblasts; Parathyroid Hormone; RNA, Messenger; Uremia; Vitamin D

Topics: Bone Diseases; Calcitriol; Dihydrotachysterol; Humans; Kidney Failure, Chronic; Renal Dialysis

This study investigates the proliferative and osteogenic role of marrow stromal/osteoprogenitor cells in the development of the cortical bone deficit in ovariectomized (OVX) female rats. In vitro, clonal growth of marrow stromal cells from OVX rats was significantly impaired (vs. sham-operated controls). Yet in vivo, cells from sham-operated and OVX rats had equal osteogenic potential in several in vivo experimental situations, such as in intraperitoneally implanted millipore diffusion chambers and in intramuscular implants of marrow plus osteoinductive bone matrix (composite grafts). Long-term (6 mo) dihydrotachysterol (DHT) treatment of OVX rats enhanced their in vitro proliferative potential and clonal growth, as well as their osteogenic expression in composite grafts. The observation that the in vivo osteogenic performance of OVX rat marrow stromal cells was normal at extraosseous sites suggests that the mechanisms leading to osteopenia may involve an abnormality in cell-matrix interactions.

Topics: Animals; Bone Diseases; Bone Marrow; Bone Marrow Transplantation; Bone Matrix; Cell Division; Cells, Cultured; Dihydrotachysterol; Disease Models, Animal; Female; Fibroblasts; Minerals; Osteogenesis; Ovariectomy; Rats; Rats, Inbred Strains; Stem Cells

Topics: Bone Diseases; Calcium; Dihydrotachysterol; Female; Genes, Dominant; Humans; Hypercalcemia; Hyperparathyroidism; Infant, Newborn; Infant, Newborn, Diseases; Parathyroid Glands; Pedigree

The case history, clinical course and laboratory findings in a 66-year-old woman with fibrogenesis imperfecta ossium are reported, the sixth case in the literature. The condition is characterized clinically by intractable skeletal pain and progressive immobility. Though serum alkaline phosphatase has been raised in all patients, there are no specific haematological or biochemical findings. The radiological features of coarse and dense trabecular pattern with symmetrical and diffuse involvement of all bones without expansion or change of shape, together with periosteal reactions and soft tissue calcification are characteristic. The macroscopic appearance of bone shows large areas of opaque white and brittle trabeculae. The histological findings mimic those of osteomalacia unless examined under polarized light which shows the loss of normal birefringence. On electron microscopy the normal lamellar pattern made up of orientated collagen fibrils all about 80 nm diameter is replaced by a random tangled pattern of much thinner irregularly curved fibrils, some as thin as 5nm. The condition appears to be acquired, leading to erosion of the normal skeleton and replacement with an abnormal fibre deficient matrix. There is no definitive therapy at present.

Topics: Aged; Alkaline Phosphatase; Autopsy; Bone Diseases; Bone Matrix; Calcium; Collagen; Dihydrotachysterol; Ergocalciferols; Humans; Male; Radiography; Skin

Topics: Bone and Bones; Bone Diseases; Calcium Metabolism Disorders; Dihydrotachysterol; Humans; Osteomalacia; Vitamin D

Topics: Animals; Bone Diseases; Calcium; Chemical Phenomena; Chemistry; Cholecalciferol; Dihydrotachysterol; Dihydroxycholecalciferols; Disease Models, Animal; Humans; Hydroxycholecalciferols; Isomerism; Kidney Failure, Chronic; Microradiography; Osteitis Fibrosa Cystica; Osteomalacia; Phosphates; Rats; Renal Dialysis; Uremia; Vitamin D

Topics: Bone Diseases; Dihydrotachysterol; Humans; Kidney Failure, Chronic; Renal Dialysis; Uremia

Topics: Arm; Bone Diseases; Calcinosis; Calcium; Calcium Carbonate; Dihydrotachysterol; Hand; Hip Joint; Humans; Hyperparathyroidism; Leg; Male; Middle Aged; Parathyroid Glands; Phosphorus; Radiography; Renal Dialysis

Topics: Adult; Bone Diseases; Calcium; Dihydrotachysterol; Female; Humans; Hypercalcemia; Hyperparathyroidism; Hypokalemia; Lactates; Male; Middle Aged; Polyuria; Prednisolone; Sodium; Sulfates; Urinary Calculi

Topics: Absorption; Adolescent; Adult; Autoanalysis; Biopsy; Bone Diseases; Calcium; Calcium Isotopes; Dihydrotachysterol; Humans; Hyperparathyroidism; Kidney Failure, Chronic; Middle Aged; Renal Dialysis; Time Factors; Vitamin D

Topics: Animals; Bone Diseases; Calcium Metabolism Disorders; Decalcification, Pathologic; Dihydrotachysterol; Femur; Microscopy, Electron; Osteocytes; Rats

Topics: Bone Diseases; Collagen Diseases; Dihydrotachysterol; Humans; Male; Middle Aged; Radiography; Vitamin D

Topics: Adenoma; Antacids; Back Pain; Biopsy; Bone Diseases; Calcinosis; Calcium; Diagnosis; Dihydrotachysterol; Humans; Hyperparathyroidism; Mandible; Parathyroid Neoplasms; Pathology; Radiography, Dental; Surgical Procedures, Operative; Tibia

Topics: Bone Diseases; Calciphylaxis; Calcium; Dihydrotachysterol; Osteitis Fibrosa Cystica; Water-Electrolyte Balance