Measurement of serum osteocalcin with a human-specific two-site immunoradiometric assay.

We developed a sensitive and specific two-site radioimmunoassay (IRMA) for human osteocalcin using human osteocalcin as a standard and two monoclonal antibodies raised against human osteocalcin purified from human cortical bone, a solid-phase anti-25-37 region and a tracer anti-5-13 sequence of the molecule. A wide range of osteocalcin levels (up to 300 ng/ml) can be measured with a sensitivity of 0.4 ng/ml.

Serum osteocalcin is increased in patients with osteomalacia: correlations with biochemical and histomorphometric findings.

The synthesis of osteocalcin or bone gla protein by osteoblasts is markedly stimulated by 1,25-(OH)2D, a key hormone in the regulation of bone mineralization. The circulating levels of osteocalcin have been shown to reflect both the osteoid matrix production and the formation rate of mineralized bone in several metabolic bone diseases (osteoporosis, thyrotoxicosis, primary hyperparathyroidism) in which both mechanisms are tightly coupled because of the absence of mineralization defect. In this study, we measured in 12 patients (7 women, 5 men, 56 +/- 15 yr old) with untreated osteomalacia serum osteocalcin and vitamin D metabolites (25OHD and 1,25-(OH)2D).

[Giant thrombosed aneurysm of the left vertebral artery developing in the fourth ventricle].

A case of giant, thrombosed, non haemorrhagic aneurysm of the distal portion of the left vertebral artery is reported. The patient came to medical attention with an acute cervical pain after a minimal cervical traumatism and a diagnosis of torticollis from rheumatologic cause was made. In fact, a few weeks before, he had suffered three episodes of right homonymous hemianopsia.

[Osteocalcin (or bone gla-protein), a new biological marker for studying bone pathology].

Osteocalcin, also called bone gla-protein, is a bone matrix protein synthetized specifically by osteoblasts. It circulates in blood where it can be assayed by the radioimmune method. We measured osteocalcin serum levels in 169 adult controls and 161 patients with different disseminated or localized bone diseases.

Serum bone gamma carboxyglutamic acid-containing protein in primary hyperparathyroidism and in malignant hypercalcemia. Comparison with bone histomorphometry.

Serum bone gamma-carboxyglutamic acid-containing (Gla) protein (sBGP), a sensitive and specific marker of bone turnover, was measured in 25 patients with primary hyperparathyroidism and in 24 patients with bone metastases with or without hypercalcemia. Despite similar levels of hypercalcemia, sBGP was increased in primary hyperparathyroidism (14.2 +/- 9.