Among the isotypes of serum tartrate-resistant acid phosphatase (TRACP), only type 5b (TRACP-5b) is derived from osteoclasts, and it is necessary to develop an assay specific for this TRACP-5b for evaluation of osteoclastic activity. Recently, a novel assay system for TRACP-5b called the fragments absorbed immunocapture enzymatic assay (FAICEA) has been developed. With two unique monoclonal antibodies, one that is highly specific for TRACP-5b and another which absorbs inactive TRACP-5b fragments that interfere with measuring active TRACP-5b, this assay provides correct measurement of TRACP-5b activity in the serum without interference by the inactive fragments of TRACP-5b and other isotypes of TRACP, especially TRACP-5a. To study the reference data of Japanese subjects, we measured TRACP-5b activity in the serum of 320 men (age, 20-82 years) and 466 women [315 premenopausal (age, 18-55 years) and 151 postmenopausal (age, 45-77 years)] with this novel assay. In men, serum TRACP-5b activity did not vary significantly with age. The postmenopausal women had significantly higher serum TRACP-5b activity than the premenopausal women. The reference intervals (logarithmic mean +/-1.96 SD) for men, premenopausal women, and postmenopausal women were 1.7-5.9 U/l, 1.2-4.4 U/l, and 2.5-7.6 U/l, respectively.

Hypocalcemiccrisis developed in a patient with monophasicsynovial sarcoma after amputation of the right leg, followed by long-term treatment with cisplatin and doxorubicin. Laboratory data revealed severe hypomagnesemia and hypocalcemia. High normal intact parathyroid hormone (PTH), elevated mid-region PTHand undetectable osteocalcin levels had already been found before the appearance of obvious symptomsconcomitantly associated with moderate hypomagnesemia and hypocalcemia. Further, both PTHlevels measured by two different methods gradually decreased until the initiation of magnesium supplementation. The magnesiumsupplement immediately relieved the tetany, and induced striking increases in both intact and mid-region PTHlevels transiently and continuous elevations of osteocalcin levels. These results suggest that magnesiumdepletion has dual effects on PTHsecretion, from stimulation to inhibition, as hypomagnesemiaprogresses. Both relative hypoparathyroidism and refractoriness of bone to PTH were thought to be responsible for hypocalcemia due to hypomagnesemia.

Introduction: Cervical myelopathy due to anomalies of the posterior elements of the axis is rare, and limited cases have been reported. This study reports such a unique case of congenital anomaly of the laminae of the axis, which is treated by partial removal of the anomalous bony structure surgically, and provides a comprehensive review of the present literature on this pathological condition. Case Presentation:A 65-year-old man presented with a 3-year history of numbness in both arms with a sensory change in the right arm. Six months before admission, he noticed weakness in his right upper extremities and stiffness of the right lower extremity. Magnetic resonance imaging (MRI) showed a bilaterally compressed spinal cord with an anomalous bony structure at the C2-3 level. Computed tomography (CT) showed an invaginated abnormal bony structure at the C2-3 level and an abnormal lateral mass on the right side at the C2-3 level. The patient underwent posterior decompression surgery using the conventional open approach. One year after surgery, his myelopathy partially ameliorated, with his cervical radiograph showing no signs of the secondary instability and MRI showing sufficient decompression of the spinal cord. The age of onset, symptoms, and surgical treatment in our case was similar to those in the 14 previously reported cases; however, the morphology of the anomaly had variations. Conclusion:This is a report of a rare anomaly in the laminae of the axis. MRI and reconstructed CT scans were useful for the treatment of this case. Partial surgical removal was an appropriate treatment for this patient, resulting in a satisfactory outcome. Keywords: Cervical myelopathy, anomaly of axis, decompression.