Fundamental Studies on Measurement of Plasma lα,25-Dihydroxycholecalciferol Concentration by Radioreceptor Assay

It is well known that 1α,25-dihydroxyvitamin D(lα,25 (OH)2D) plays an important role in the pathophysiology of bone and calcium metabolism. In present paper, we established a relatively convenient assay system, using radioreceptor assay, for lα,25 (OH) 2D. Fundamental studies showed that this assay system had good sensitivity enough to detect 2 pg of lα,25 (OH) 2D per tube, and had good reproducibility. Therefore, it was shown that this assay system could be applied for clinical use. The plasma concentrations of lα,25(OH)2D, measured by this assay system, in healthy young males and females, and in aged females were 55.7±16.1, 44.8±22.1 and 23.5±13.0 pg/ml (mean±s.d.), respectively. Thus, the aged females showed significantly lower (p<0.005) lα,25 (OH)2D levels than the young group. This fact suggests that vitamin D deficient state might exist in aged females

Vertebral Bone Mineral Density Measured with Dual Photon Absorptiometry Using a Gamma Camera: Clinical Application to Metabolic Bone Diseases

Dual photon absorptiometry (DPA) with a gamma camera, instead of a rectilinear scanner, has been developed for vertebral bone mineral density (BMD) measurement. The system consists of 50 mCi (1,850 MBq) 153-Gd as the emitting source, and an Anger-type gamma camera with a rectangular Nal (Tl) crystal and 22 photomultiplier tubes. The effective field of a view was enough to cover more than 3 vertebrae. With the patient sitting, data acquisition was performed. The spatial resolution and uniformity of the gamma camera were good. With the introduction of a correction equation, the error in calculated BMD due to body thickness was reduced. A data acquisition of 7.5 to 15 min led to a satisfactory C.V. value (less than 2.0%). The precision (1.63% of C.V. in vitro and 3.53% in vivo) and accuracy (r=0.999) of the BMD measurements were also good. Vertebral BMD values in 300 normal Japanese females decreased with aging. Although in involutional osteoporosis and secondary hyperparathyroidism both vertebral and radial % BMDs decreased, in steroid-induced osteoporosis and primary hyperparathyroidism, disproportionate bone loss (relatively lower in vertebral bone) was demonstrated. Thus, it was shown that a newly developed DPA system using a gamma camera provided sufficient precision and accuracy to quantificaticn of vertebral BMD, and its application should provide reliable information for clarification of the pathophysiology of metabolic bone diseases

Effects of Treatments for Experimental Bone Tumor on Prostaglandin E Level and Bone Scintigrams

The role of Prostaglandin E (PgE) level was studied experimentally as follows: 1) intrahepatic implantation of VX-2, 2) intravenous injection of VX-2, 3) effect of treatments on intramedullary implanted VX-2. The levels of PgE in intrahepatic and intravenous transplantation were not higher than that of intramedullary transplantation. Mitomycin C (MMC) did not reduce the PgE level and appearance time of bone scan abnormality was the same as that of untreated animals. A combination of indomethacin and MMC caused a delay in appearance time of bone scan abnormalities

A Newly Developed Instrument of Dual Photon Absorptiometry for Bone Mineral Analysis of the Lumbar Vertebra: Study in Control and Aged Females

In order to determine the quantitatively bone mass, dual photon absorptiometry instrument using a scintillation camera was newly developed, and its basic performance was described. Furthermore, with this instrument, bone mineral at 3rd lumbar vertebra was measured in 57 women (31 controls: age 29.9±6.4 yrs., and 16 seniles: age 67.7±6.6 yrs.). The aged females, compared with the young control females, showed significantly low the all parameters of bone mineral such as bone mineral content (BMC), bone mineral density and total BMC at 3rd lumbar vertebra. Thus, it was shown that assessment of bone mineral with this instrument provided a useful information in the diagnosis of osteoporosis

Assessment of Bone Scintigraphy Showing Markedly Increased Accumulation in Mandibular and Maxillary Lesions of Cementifying Fibroma

This report concerns with three cases of cementifying fibroma showing markedly increased accumulation of 99mTc-MDP in mandibular and maxillary lesions. The bone scintigraphic and histopathological findings are presented and discussed

Scintigraphic Findings of Bone and Bone-Marrow and Determination of Bone Mineral Density Using Photon Absorptiometry in Osteopetrosis

On a 15-year-old girl with osteopetrosis, bone and bonemarrow scintigraphy were performed. Also, bone mineral density (BMD) with quantitative CT (QCT), single photon absorptiometry (SPA) and dual photon absorptiometry (DPA) were measured. On bone scintigraphy the diffusely increased skeletal uptake and relatively diminished renal uptake were noted. On the other hand, on bone marrow scintigraphy poor accumulation in central marrow and peripheral expansion were shown. BMD value by QCT and DPA (mainly trabecular bone) was markedly high, while BMD by SPA (mainly cortical bone) was within normal range. Thus, it was shown that bone and bone-marrow scintigraphy combined with BMD measurement by photon absorptiometry were useful and essential in evaluating the pathophysiology of osteosclerosis

Comparative Studies of Values of Bone Mineral Density Measured with Different Photon Absorptiometries : A Preliminary Report

In order to compare values of bone mineral density measured with various photon absorptiometries, fundamental studies, using four different types of phantoms were performed in four instruments. The QDR-1000 (dual energy X-ray absorptiometry, DEXA) and Dualomex HC-1 (dual photon absorptiometry) were employed for the determination of bone mineral of a lumbar phantom and a cylindrical phantom, and the DCS-600 (DEXA) and Bone Densitometer (single photon absorptiometry) were used for the determination of bone mineral of a rectangular phantom and a ring phantom. The results indicate that the methodology for identification of the bone edge, which is necessary to calculate bone area or bone width, and the bone mineral per unit volume, which is defined as the line bone mineral content per cross-secional area, differ with the instruments used. Furthermore, the bone mineral per unit volume depends on the bone shape of the measured objects. Therefore, it seems taht the cross calibration of bone mineral density between instruments using phantoms is limited and in vivo investigation will be required in the future

The Usefulness of Bone Scintigraphy in the Detection of Hypertrophic Pulmonary Osteoarthropathy

In a patient with lung cancer, increased accumulation in both lower legs on bone scintigraphy with 99mTc-hydroxymethylene diphosphonate was confirmed radiographically to be hypertrophic pulmonary osteoarthropathy. A characteristic scintigraphic pattern of radionuclide accumulation could be distinguished from bone metastasis

Measurement of Ionized Calcium as Supplementary Marker of Bone Metastasis in Breast Cancer

The serum concentrations of ionized calcium (iCa), corrected automatically for serum pH, were measured in 67 cases with breast cancer (16 positive cases and 51 negative cases for bone metastasis). The serum concentration of iCa in the cases of positive bone metastasis was significantly higher than that in the negative cases (p<0.005). As osteoclastic bone metastasis occurred frequently in breast cancer, the measurements of serum concentrations of iCa might be of help as a supplementary marker of the diagnosis of bone metastasis

Skeletal Metastasis in Renal Cell Carcinoma: Photon Deficiency on Bone Scintigraphy

Bone scintigraphy with 99mTc-labeled phosphorous compound is an excellent technique for the detection of bone metastasis. Bone metastases are usually visualized as multiple hot spots on bone scintigraphy. However, photon deficiency in the metastatic lesion on bone scintigrams is reported in few cases with malignancy. In this study, we have evaluated the photopenic bone metastasis from renal cell carcinoma by the radiographic and computed tomographic examinations. Photon deficient metastatic lesions were seen on bone scintigraphy in 5 patients with renal cell carcinoma. All of the photon deficient lesions were osteolytic on bone radiography and computed tomography. The pure photon deficient lesions not associated with surrounding hot margins were seen on the thoracic vertebrae and rib and the ones with surrounding hot margins were seen on the sternum, pelvis and femur. This difference may be due to the differences in the growth rate of the tumor and reactive hyperemia and new bone formation in the metastatic lesions