Photo-density and fracture load of the femoral neck were both measured, for an experimental osteoporosis, induced by hemicordotomy combined with ovariectomy in the rat. A significant decrease in these values directly proportionate to the progression of the osteoporosis, was observed. Photodensity of the femoral neck showed a significant correlation to the fracture load and also to the cortical thickness index (CTI) and bone density (ΣGS/D) at the femoral midpoint. Furthermore, administration of 1α(OH) vitamin D3 caused a significant increase in the photo-density and fracture load of the femoral neck.
We used a computer to assess the degrees and types of the vertebral deformity on simple lateral X-ray pictures of thoracic and lumbar vertebrae. We studied X-ray pictures of 120 females who were diagnosed as having postmenopausal or senile osteoporosis. The vertebral deformities were classified into five types; N: normal; I: vertex vertebra; II: fish vertebra; III: vertebra plana; IV: reverse vertex vertebra. Also, visual assessment of X-ray pictures was carried out by physicians. 3,018 of a total of 3,419 vertebral bodies were judged as normal (N) by physicians. 2,904 of these 3,018 vertebral bodies were judged normal (N) by our computer method. The rate of conformity was 96.22%. For vertex vertebra (I), fish vertebra (II) and vertebra plana (III), the rate of conformity the was 84.64%, 90.48% and 60.56% respectively. As a judgement of the presence/absence of the vertebral deformity, the computer method indicated that 114 of 3,018 vertebral bodies judged to be normal (N) by physicians were more or less deformed.
In order to evaluate the efficay of 1-hydroxyethylidene diphosphonic acid disodium (EHDP) and actinomycin D as the agents for the treatment of malignancy-associated hypercalcemia, a randomized study was carried out, in which the effects of these agents were compared with those of calcitonin (elcatonin) and mithramycin. EHDP (400 mg/day, daily) was effective in 4 of 9 cases (44%) and actinomycin D (12.5µg/kg) in 6 of 10 cases (60%), while calcitonin (80–160 units/day, daily) was effective in 6 of 12 cases (50%) and mithramycin (25µg/kg) in all of 11 cases. In effective cases, the mean decreases in corrected serum calcium levels after the treatments were 3.2±1.2 by EHDP, 3.4±1.2 by actinomycin D, 2.9±0.6 by calcitonin and 4.1±1.2 by mithramycin (mg/dl, mean±SD). Mithramycin was, therefore, most effective, but it is not commercially available in Japan, and the duration of its effect was much shorter than that of EHDP or actinomycin D. These results together with the fact that EHDP is given orally, indicate that EHDP and actinomycin D are as effective as calcitonin and that EHDP may be beneficial for the treatment of mild to moderate hypercalcemia.
We have measured serum osteocalcin (OC) by radioimmunoassay in normal children, adults and patients with glucocorticoid-induced osteoporosis in childhood. And we have compared its concentration to the severity of osteoporosis evaluated by Jikei Medical College Classification.
Vertebral trabecular mineral density of healthy Japanese (91 females and 67 males) was measured using the quantitative computed tomography (QCT) technique in a cross-sectional study. We compared estimates of vertebral bone density using two calibration phantoms: the Genant K2HPO4 phantom developed by Genant and a solid CaCO3 phantom developed by Chugai Pharmaceutical. Using the CaCO3 phantom, the rate of decrease of spinal trabecular mineral with age in control females averaged 1.1% per year from age 20 to 80, with an accelerated loss demonstrated at menopause (1.8%). Trabecular bone mass in male controls declined an average 0.9% per year. There was a highly significant correlation between the results obtained with each phantom (r=0.980, p<0.001). This relation was linear over the range of bone mass (60 –172 mg K2HPO4/cm3), and was expressed by the equation y(CaCO3)=1.26×(K2HPO4)+12.3 There was, however, some dispersion of the data around the regression. The calibration phantom used for the measurement of the vertebral trabecular bone should need to be more consistent in longitudinal studies. Apart from this consideration, a solid Chugai phantom can be said to be useful having practical advantages in its flexibility.
For the purpose of non-invasive quantification of trabecular mineral content of the third lumbar vertebra, quantitative computed tomography (QCT) using reference phantom was conducted. In order to minimize the error, the lumbar spine to be measured should be brought to the center of CT gantry, the phantom should be brought into close contact with the object for measurement, scanning should be carried out on 10mm slice thickness and the ROI (region of interest) should be taken as large as possible, according to our experience. Comparison of QCT values among various CT apparatus was difficult. This method was applied to the measurement of trabecular mineral content of the third lumbar vertebra. In 151 control subjects, the trabecular mineral content of the third lumbar vertebra decreased from the 3rd decade. In the initial adult period, females showed higher trabecular mineral content than males. A rapid loss of trabecular mineral content occurred between the 5th and 6th decade in females, so that after the 7th decade, males had higher trabecular mineral content than females. 47 patients with spinal osteoporosis and 16 patients with fracture of the femoral neck gave significantly lower trabecular mineral content than subjects in the same decade group without those conditions.
Three pediatric patients with renal osteodystrophy were treated with 1αOHD3 and 24, 25(OH)2D3. While serum calcium level significantly decreased, no significant effects were found on serum phosphorus, alkaline phosphatase, parathyroid hormone and urinary excretion of calcium. These results suggest that 24, 25(OH)2D3 may play some roles in bone and mineral metabolism.
In order to confirm the effect of calcium-binding protein in bovine milk (mCaBP) on intestinal calcium absorption, calcium transport was measured in the presence and the absence of exogenous mCaBP using the everted gut sac method and ligated-loop method. Exogenous mCaBP significantly stimulated the absorption of calcium in the lower ileum, but not in the duodenum in both vitamin D-deficient and normal rats only as determined by the ligated-loop method. These observations suggest that the stimulating mechanism of exogenous mCaBP for calcium transport is clearly different from that of vitamin D-dependent CaBP in intestinal epithelial cells, and that calcium transport in the lower intestine is effectively stimulated in the presence of both exogenous mCaBP and vitamin D-dependent CaBP. These results are tempting to suggest that mCaBP and vitamin D-dependent CaBP participate at the outside and the inside of epithelial cell, respectively, to stimulate intestinal calcium absorption, and both CaBPs interact each other in calcium transport system. The mechanism of mCaBP action in the intestine is still unclear.
A 15-year-old girl exhibiting short stature, obesity, stubby short fingers and short upper limbs was diagnosed as having pseudohypoparathyroidism type I. Endocrinological examination revealed the functional consequences of the parathyroid hormone receptor defect at the kidney. Skeletal roentgenograms of the upper limbs demonstrated bilateral shortening of the humerus with marked deformity in the proximal portion of the bones. To our knowledge, there has been no report of a similar humerus abnormality associated with pseudohypoparathyroidism.
The distribution of alkaline phosphatase in dentinogenically active bovine dental pulp tissues was investigated histochemically and biochemically. Histochemical observation showed a high enzyme activity in the subodontoblastic layer, especially in coronal pulp and also in the core of radicular pulp. Biochemical results were well consistent with histochemical findings. Alkaline phosphatase activity in the coronal pulp was twice that in radicular pulp. Most of the enzyme activity in coronal pulp was in the subodontoblastic layer (91%), whereas the activity in the radicular pulp was evenly distributed. Since undifferentiated mesenchymal cells were observed in the areas showing relatively high ALPase activity, it seemed that there were some relations between the inducion of ALPase and the undifferentiated mesenchymal cells.
In order to clarify the coupling mechanism (or phenomena) of the bone resorption-formation in the remodeling process, this study was attempted to observe the histochemical location of acid phosphatase (ACPase) and tartrate-resistant ACPase (TRACPase) activity of the newly formed cement lines and the mononuclear cells in BMU (basic multicellular unit) using JB-4 embedding technique for the demonstration of ACPase and TRACPase activity on the tibial metaphysis of rat.
We compared the results of microdensitometry of the second metacalpal with those of histomorphometry of the biopsied iliac spongiosa in metabolically normal subjects, thirty seven females and twenty males, with the mean age of 44.7 years. Correlation coefficient with bone area was 0.681 for MCI (p<0.001), −0.679 for d (p<0.001), 0.650 for ΔGSmin (p<0.001), 0.635 for E (p<0.001), 0.600 for ΔGSmax (p<0.001), 0.563 for ΣGS/D (p<0.001), −0.226 for D (N.S.), 0.179 for F · GS(N.S.). Correlation between parameters of histomorphometry of iliac biopsy specimen and each index of metacalpal microdensitometry was generally high.
In order to separate only the mineral and collagen binding (MCB) proteins from the mineral compartment of newborn rat calvaria after the mineral unassociated proteins were removed by washing in 4 M guanidine solution, the sequential extractions were carried out by homogenizing in acetic acid and several neutral solutions with a different ion concentration.
Disturbances in extracellular (systemic) and intracellular calcium metabolism have been demonstrated. Intracellular free calcium in vascular smooth muscle cells is elevated, which is believed to be the final determinant of vascular tone, thus blood pressure. This hypothesis is supported by the fact that calcium channel blocker reduces blood pressure in hypertension by blocking both receptor-operated and potential-operated calcium channel. On the other hand, calcium balance appears to be negative in hypertension and dietary supplement of calcium has been demonstrated to be effective in reduction of blood pressure in both animals and humans with high blood pressure. The latter observation seems to be opposite to the effect of calcium channel blocker, since restored calcium balance may increase intracellular free calcium concentration by supplying higher amount of extracellular (plasma) calcium to the cell membmane, which is leaky in hypertension. The effect of dietary calcium supplement may be explained by changes in calcium regulating hormones but not calciumper se. Recent data on calcium metabolism in the spontaneously hypertensive rats and effect of vitamin D in vascular smooth muncle cells will be discussed in relation to the regulation of vascular tone and blood pressure.
Dentins of rats were demineralized and the sections mineralized in vitro. Whether the distribution of mineral of the sections mineralized in vitro reproduces it of dentins formed in vivo and whether the distribution correlates with the nature of the matrices of dentins were examined by contact microradiography (CMR) and staining with hematoxylin. The abnormal layers induced to the dentins of rats administered Ni-salt or Mn-salt were chosen as the subjects of the examination.
The morphological informations retrieved from X-ray pictures were investigated to clarify the relationship among themselves by multidimensional analysis. We studied the X-ray pictures of the dorsal and lumbar spines from 147 male subjects aged 22–87 years, and 286 female subjects aged 18–102 years. We picked up seven morphological items from X-ray pictures as informations and two attributable items of sex and age. The result calculated by quantification IV presented the similar quality of five items which were global judgment, spinal score, deformity of vertebral body, calcification of abdominal aorta, and sex. By using quantification I, global judgment could be explained by four items which were spinal score, deformity of vertebral body, osteophyte, and age. The result calculated by quantification III showed also the similar quality of four items which were global judgment, spinal score, deformity of vertebral body, and age except osteophyte which had a different character. The different character of osteophyte could discern each subject of old age into two groups by quantification III, one with osteophyte and the other without osteophyte. The expected values of global judgment of osteoporosis by quantification I were well correlated with not only spinal scores and deformity of vertebral bodies but also with ages.
Mononuclear phagocytes are frequently found adjacent to active bone-resorbing surfaces in both physiological and pathological bone resorption, being implicated as important cellular elements in the process of bone resorption. In this study an attempt was made to prepare several groups of peritoneal exudate cells (PEC) induced by bone powder (B-PEC), glycogen (G-PEC) or paraffin oil (P-PEC), to investigate the chemotactic response to bone powder suspension or bone matrix and the superoxide production.
The demineralized sections of dentins of rats were mineralized in vitro. The sections were observed with contact microradiography (CMR) and their mineral contents were determined with micro-photometry of CMR films.
Over the last 5 years new developments in techniques to study the cell biology of the osteoclast have greatly increased our understanding of the biological and functional properties of osteoclasts. The osteoclast, which is the primary bone resorbing cell, has been extremely difficult to study because of its inaccessability and fragility. In vivo studies of the origin of osteoclasts have demonstrated that the osteoclast is hemopoietic in origin. This conclusion is based on parabiotic (1-4) and transplantation studies in animals(5-11) which have demonstrated that hematopoietic tissues such as spleen and bone marrow as well as peripheral blood contain osteoclast progenitors. Similarly, bone marrow transplantation studies in man (12, 13) have shown that marrow transplantation can cure some patients with infantile osteopetrosis. However, these in vivo studies have n~)t been able to identify which lineage of marrow cells gives rise to osteoclasts. In addition, a useful osteoclast cell line has not been available for cell biological and physiological studies. Therefore, model systems to circumvent this difficulty have been developed for studying factors affecting osteoclast activity and formation as well as osteoclastic bone resorption.
