Showing papers in "Clinical calcium in 2003"

Epidemiology of osteoporotic fractures

Abstract: Patients with vertebral, hip, distal radius, and proximal humerus fractures are most common among the osteoporosis-related fractures. The incidences of these fractures increase with age, however, the increase patterns differ between the fracture sites. The prevalence of vertebral fracture for Japanese is similar or slightly higher and the incidences of osteoporosis-related limb fractures are lower than those for Caucacians. A decrease in prevalence of vertebral fractures and an increase in the incidence of limb fractures are the secular trend in Japan. Previous fractures are significant risk factor for both vertebral and hip fractures. Greater physical activity increases the risk of distal radius fractures, and decreases the risk of proximal humerus fractures.

Calcium and the risk for periodontal disease

Abstract: Recently, there is much interest regarding the relationship between periodontal disease and the life style as well as systemic disease including osteoporosis. In addition, there is increasing awareness that dietary calcium intake and other nutrients are important for prevention and management of periodontal disease. In this paper, a cross-sectional study from NHANES III for investigating the association between dietary calcium intake and periodontal disease is introduced, and the management of periodontal disease is proposed from nutritional aspects.

Calcium and bone metabolism during pregnancy and lactation

Abstract: Estrogens regulate the bone metabolism, adversely affecting peak bone mass and prohibiting the bone loss. The high gestational estrogens has made us suppose that the maternal bone would be protected. However, the maternal bone mineral density (BMD) is found to decrease. In addition, postpartum lactational low estrogens and PTHrP induce to lower the BMD. These two gestational phases cause complicated bone metabolisms, resulting to bone loss with different pathophysiologies., Breastfeeding places significant stress on calcium metabolism and, as a consequence, directly influences bone metabolism. In short time after the end of lactation, the bone recovers to prepregnant state.

Effects of ovariectomy on trabecular structures of rat alveolar bone

Abstract: To clarify the relationship between estrogen deficiency and tooth loss, we analyzed the trabecular structural changes of mandibular alveolar bone in ovariectomized rats. Two months after ovariectomy, the bone resorptive activity remarkably accelerated and caused high bone turnover. On the other hand, one year after ovariectomy, bone loss and trabecular fragmentation occurred in the alveolar bone, although the accelerated degree of bone resorptive activity was moderate. If elderly women could experience similar changes on their alveolar bone, we must pay more attention to the bone resorption presently after menopause and the trabecular fragility long after menopause.

Estrogen and bone metabolism

Abstract: The increased rate of bone remodeling that follows loss of estrogen can be accounted for by increased osteoclastogenesis (formation of bone-resorbing cells) and osteoblastogenesis (formation of bone-forming cells). And, estrogen replacement provides an effective prevention of postmenopausal osteoporosis. Genomic and non-genomic actions of estrogen regulate bone remodeling.

AO classification of fractures

Abstract: In the AO classification, the diagnosis of a fracture is expressed by its location (bone and segment) and morphological features, which is characterized by the hierarchical organization into triad. This classification is comprehensive and very useful in a daily clinical practice.

Surgical management of the diabetic foot

Abstract: Diabetic foot is one of challenging diseases in vascular surgery. This is based on uncontrolled diabetes mellitus and its true character is the neuropathic gangrene due to microangiopathy. Diabetic foot, however, is sometimes accompanied by peripheral arterial occlusive disease, which true status is macroangiopathy. Therefore, the strategy for diabetic foot is as follows;the first step is the infection control by minor amputation and/or drainage, the second step is the assessment of the limb ischemia, and the final is the complete vascular reconstruction. To salvage these diabetic feet, it is important that doctors, who concern to diabetics, understand these strategies and also that they have a settled opinion for the diabetic foot.

[Glucocorticoid-induced osteoporosis, up to date].

Abstract: Glucocorticoid-induced osteoporosis (GIO) has been a hot topic in recent years. Glucocorticoids (GC) increase a fracture risk depending on the doses and affected especially vertebral bones. After cessation of GC, the fracture risk falls promptly, but does not reach at an equivalent level to non-medication. Moreover, a threshold of bone mineral densities predicting a fracture is higher in GIO than that in post-menopausal osteoporosis. Renewal of the management for GIO from UK is based on new knowledge. Risk factors other than bone mineral densities have been taken into consideration in renewing the management. An original management plan in Japan is expected coming soon. Further development of future research is needed.

Pharmacological actions and pharmacokinetics of bisphosphonates

Abstract: Bisphosphonates are potent inhibitors of osteoclastic bone resorption and have been used for the treatment of various metabolic bone diseases such as osteoporosis and hypercalcemia of malignancy. However, the pharmacological action, the mechanism of action, and even side effects vary depending on the chemical structure of the side chain attached to the carbon atom of P-C-P bond. This review discussed about the pharmacological characteristics and possible application of different classes of bisphosphonates with different side chains.

[Relationship between estrogen-receptor genotype and tooth loss in postmenopausal women].

Abstract: Tooth loss is known to be influenced by environmental factors, but the role of genetic factors remains unknown. It is likely that the estrogen-receptor (ER) gene could be associated with tooth loss in women because recent studies in the United State reported the protective effect of estrogen replacement therapy on tooth retention in the elderly. We first demonstrated relationship between ER genotype and tooth loss in post-menopausal women. However, further investigation is necessary to clarify unknown pathways in which ER genotype contributes to tooth loss in women.

Mechanism of cartilage destruction in rheumatoid arthritis

Abstract: Destruction of cartilage in rheumatoid arthritis (RA) is mediated mainly by proteinases which can degrade cartilage matrix including type II collagen and aggrecan Of these proteinases, matrix metalloproteinases (MMP) play significant roles in RA pathology, however recent studies show that a disintegrin and metalloproteinase (ADAM) families are another candidates These proteinases are mainly produced from synovial cells and inflammatory cells, and concentrations of these proteinases in synovial fluid are significantly higher in RA than in OA Several proteinases have been shown to express in chondorocytes of RA and these chondrocytic proteinases are thought to mediate cartilage destruction in RA Apoptosis which is mediated by nitric oxide (NO) is another pathway of cartilage destruction in RA

[Pathogenesis and treatment of glucocorticoid-induced osteoporosis].

Abstract: Prevention of glucocorticoid-induced osteoporosis (GIO) and the subsequent bone fractures is now essential for QOL. Direct inhibitory effect of glucocorticoid on bone formation and promotion of apoptosis of bone cells are currently thought to be the major mechanism of GIO. Bone resorption varies dependent on dose and length of administration of glucocorticoid, but the bone formation rate is considered to be always below the bone resorption rate. Most recent clinical guidelines have recommended bisphosphonates as the first choice for the treatment of GIO.

[Leflunomide: clinical effectiveness and mechanism of action].

Abstract: Leflunomide is a new immunomodulatory agent by selectively inhibiting the de novo pyrimidine synthesis. Its active metabolite (A77 1726) is highly bound to plasma protein and has a long half life. Through several large trials describing its efficacy and safety including retardation of radiographic progression in comparison with both sulfasalazine and methotrexate and with placebo have been published in Europe and the United States, leflunomide was shown to improve primary and secondary outcome measures with satisfactory safety profile. The most common treatment-related adverse reactions were diarrhea, nausea, and abnormal plasma liver enzyme levels. Leflunomide may be a useful addition to the current management of rheumatoid arthritis.

Osteoporosis and periodontal bone loss.

Abstract: Osteoporosis and osteopenia are characterized by reductions in bone mass, and may lead to skeletal fragility and fracture. Until the advent and widespread use of such methodology to measure bone density, such as dual energy X-ray absorption (DXA), the definition of osteoporosis was usually made using the clinical signs of a fracture. In 1994 the World Health Organization defined osteoporosis as a bone mineral density level more than 2.5 standard deviations below the mean of young normal women (WHO, 1994). The potential inter-relationship of the two diseases will be discussed in this paper.

Skeletal and mandibular bone mineral density in dentate and edentulous postmenopausal women

Abstract: Tooth loss is one of risk factors for osteoporosis. Reversibly osteoporotic condition is one of putative risk factors for tooth loss. The balance of bone remodeling in jawbone shift to absorption in systemically osteoporotic individuals and result in enhancement of tooth loss. The presence of tooth and skeletal and mandibular bone metabolism may relate to one another. We investigated the relationship between the presence of the tooth and skeletal and mandibular bone mineral density (BMD) in postmenopausal women. Periodontally healthy and edentulous subjects participated in this study. BMD of the lumbar spine and mandibular bone was determined. The results suggest that the presence of tooth contribute to maintain the BMD of mandibular cortical bone in postmenopausal women. Direct masticatory forces via natural teeth may influence the mandibular cortical bone metabolism and if tooth loss occurs, the bone metabolism may be regulated similar to other skeletal bone.

Osteoporosis in anorexia nervosa

Abstract: Anorexia nervosa (AN) has recently become one of common disorders in adolescent girls. A chronic course of AN is related to morbidity, with one of the most serious medical complications being severe osteopenia. The prevalence of osteoporosis is estimated to be 40 % in AN during the follow up. The incidence of bone fracture in AN after the recovery of body weight is reported to be two to seven higher than that in healthy age-matched controls. Because adolescence is a critical time in terms of acquisition of peak bone mass, osteopenia during this time may be permanent. Adult woman with adolescence-onset AN has lower bone mineral density than that with adult-onset AN. In addition, bone mineral density (BMD) of AN has been shown to be influenced by several factors, including reduced body weight due to malnutrition, intake of calcium and vitamin D, and duration of estrogen deficiency. Among them, body weight is known to be the most important prognostic factor, both in a short and long period of years. Thus, medical doctor should monitor BMD in patients with AN throughout their life.

[Osteopontin: a topic from the point of bone morphology].

Abstract: Osteopontin is one of the abundant non-collagenous matrix proteins in bone matrix. It is present as approximately one tenth of the non-collagenous bone matrix protein. The structure of the protein contains RGDS motif required for cell attachment and activation of integrins, especially the alpha v beta 3 integrin which is expressed at high levels in osteoclasts and budding vessels. Osteopontin is present particularly at high concentration in the lamina limitans and cement line, suggesting its role in the initiation and termination of the bone turnover.

Epidemiology of falling

Abstract: It has been only some 10 years since the study of falls among old people was initiated in Japan. The incidence of falls depends on age, sex, health condition including underlying diseases, and extrinsic factors (e.g. living environment). The incidence of falls among community-dwelling elderly in Japan varies from approximately 10 to 25%, however, that among the elderly people in medical or care institutions is approximately 20 to 35%, being lower than that in US and European countries. The incidence of falls was higher in women than in men, and that it increased sharply with advancing age. Fall experience within one year preceding the survey was one of the major significant predicting factors. The available literature showed that exercise programs have beneficial effects. The exercises need to be regular and sustainable.

Effects of bisphosphonate on the inflammation

Abstract: Etidronate and clodronate, non amino-containing bisphosphonates (non N-BPs), have been shown to have anti-inflammatory and analgesic effects. That efficacy of non N-BPs can be observed in the same doses as for osteoporosis. Several reports suggest that non N- and N-BPs have the distinct effects on inflammatory processes. The anti-inflammatory properties of etidronate should be evaluated.

[Treatment of periodontal disease, prevention and bisphosphonate].

Abstract: The bisphosphonate has a high affinity in the hydroxyapatite which is the main constituent of the bone and remarkably suppresses the bone resorption. Thus bisphosphonate administer inhibits the resorption of the alveolar bone and the jaw bone with periodontitis, and there is a possibility of contributing to the treatment of the periodontitis. Then, the etidronate was prescribed for four patients periodontitis for 2-3 years according to the usual dose of the osteoporosis in addition to dental treatment, and the clinical course was followed. It is considered that etidronate controls the resorption of the alveolar bone for 2-3 years, maintains structure and function of the gums and the periodontal tissue, and is useful as the remedy of chronic periodontitis.

Clinical aspects of partial androgen deficiency of aging male (PADAM)

Abstract: PADAM (partial androgen deficiency of aging male) is a biochemical syndrome associated with a deficiency in serum androgen levels. PADAM is characterized by diminished sexual function, decrease in spatial orientation ability, lean body mass and bone mineral density and increase in visceral fat. The measurement of serum total and/or free testosterone is acceptable to evaluate serum androgen levels. During androgen replacement treatment, several adverse effects including prostate safety, liver function, polycythemia and sleep apnea should be periodically monitored.

Parathyroidectomy for patients with renal osteodystrophy

Abstract: It has been proposed that we should focus our attention on prevention of cardiovascular complication rather than to prevent osteitis fibrosa as the purpose to control secondary hyperparathyroidism (2HPT) induced by chronic renal failure. Active vitamin D and these analogues influence the bone turnover in hemodialysis patients and recently we often encounter the patients whose bone turnover is not high in spite of high PTH level. The aim of parathyroidectomy is gradually changed from improvement of bone disease to reduce high PTH level to prevent cardiovascular complication and extraskeletal symptoms. When it is difficult to control high PTH level without increase of calcium phosphate product, parathyroidectomy should be chosen.

[Epidemiology of osteoporosis: gender differences].

Abstract: Although no sex difference is observed in bone mineral density (BMD) during the first five decades of life, BMD is lower in females than in males at the age of 50 and older. The prevalence of osteoporosis and the incidence of osteoporosis-related bone fracture in females are two-fold or more higher than in males. BMD is an important predictor of bone fracture risk in both sexes, and there is no sex difference in its predictability. After adjustment is made for BMD, the sex difference in the incidence of vertebral fracture almost disappears. The sex difference in BMD virtually explains the sex difference in the incidence of spine fracture.

[Osteosarcoma in rats receiving long-term PTH injection].

Abstract: Daily injection of human PTH (1-34) to osteoporotics has been shown to increase bone mineral density and reduce fracture risk within 18 months. Despite its impressive effects on human bone, safety became a big issue when it was revealed that up to 53% of rats received hPTH (1-34) for 2 years developed osteosarcoma. On the interpretation of the data, most experts agreed that this is unlikely to predict an increased risk of osteosarcoma in human osteoporotic patients. Some of the reasonings are as follows: (1) fundamental differences in bone metabolism between rat and human, (2) rats received PTH at a dose 12-25 folds of the human dosage, for 80-90% of their life span whereas in human PTH would be used for only 2-3% of the life span.

Intestinal calcium absorption and vitamin D

Abstract: Vitamin D is required for efficient absorption of dietary Ca. Accumulated observations indicated that active form of vitamin D is involved in the three steps of intestinal Ca absorption:incorporation of Ca by epithelial cells through brush border membrane, intracellular Ca movement, and excretion of Ca into systemic circulation via basolateral membrane. It is also known that activated vitamin D takes part in growth and differentiation of intestinal epithelial cells.

Mechanisms of joint destruction in rheumatoid arthritis

Abstract: A variety of destructive enzymes are secreted by pannnus. Prominent among these are the various matrix metalloproteinases (MMPs) and cathepsins. These enzymes act upon collagen and the proteoglycan matrix, thereby destroying the central structure of articular cartilage. Other destructive factors include the cytokines TNF-alpha and IL-1, which activate osteoclasts to resorb subchondral bone. A further important mediator is the recently described osteoclast differentiation factor (ODF) (also referred to as TNF-related activation-induced cytokine [TRANCE], receptor activator of nuclear factor kappaB ligand [RANKL], or osteoprotegerin ligand).

Recommended daily allowance and dietary reference intakes for vitamin D and calcium in Japanese

Abstract: In the sixth edition of the recommended dietary allowance (RDA) for Japanese-dietary reference intakes by the Ministry of Health, Labour and Welfare, Japan, RDA and tolerable upper limit (UL) for vitamin D and calcium were set RDA and UL for calcium were set on the basis of the calcium balance study and the factorial method In contrast, plasma 25-hydroxyvitamin D level in subjects as a maker reflecting vitamin D nutrition status was first used for setting the RDA and UL in this edition

Vertebroplasty for osteoporotic vertebral compression fractures

Abstract: Vertebroplasty for osteoporotic vertebral compression fractures is a minimally invasive procedure which could provide immediate pain relief by injecting PMMA into the vertebral body percutaneously. Kyphoplasty, which is designed to restore the vertebral height by inflating balloon, has recently been developed and the excellent early clinical results were reported. Calcium phosphate cement may have potential advantages over the PMMA for the use in vertebroplasty or kyphoplasty.

Correlation between periodontal disease and osteoporosis using panoramic radiographic parameters for diagnosed osteoporosis in dental clinic

Abstract: The correlation between periodontal disease and osteoporosis was evaluated by comparing age, panoramic radiographic and clinical parameters of periodontal disease. Diagnosis of osteoporosis in periodontal diseased patients was evaluated by panoramic radiographic parameters (mandibular cortical width:MCW). Subjects which had more than 20 teeth and examined by panoramic radiography were untreated adults with periodontal disease who were free of other systemic disease. The following parameters were examined on panoramic X-ray film:alveolar bone loss (ABL), mandibular bone mass with the use of mandibular cortical width (MCW). ABL was significantly higher and MCW significantly lower in the postmenopausal group (>6 years after menopause). The number of teeth was significantly lower and CAL significantly higher in the postmenopausal group (>11 years after menopause). Age and ABL correlated positively in men and women. Years after menopause and ABL and MCW and CAL in the postmenopausal group were correlated positively. Women whose MCW was less than mean - 2 SD should be diagnosed with osteoporosis. Our results demonstrated that periodontal disease correlates with osteoporosis, and MCW could be useful in detecting of osteoporosis in women with periodontal disease.

Spectrum of renal osteodystrophy

Abstract: The term "renal osteodystrophy (ROD) " had been proposed by the two Chinese physicians as the general term for the bone complications associated with the chronic renal disease patients in 1943. The pathogenesis of original ROD has been recognized as the results of the active vitamin D deficiency and secondary hyperparathyroidism. Although recent advances of dialysis treatment have supported the uremic patients alive for more than 10 to 20 years. Such an unphysiological condition might deteriorate the original bone diseases, change the quality of them, or produce the new types of bone disease. Long-term administration of the drugs could also affect the bone disease. Then we have to reconsider the ROD classification. We are now meeting two types of ROD, one of them is the classical or original ROD, and the another one is the dialysis-related or drug-induced osteoarthropathy such as aluminium osteopathy, adynamic bone disease, amyloid-related osteoarthropathy as well as uncontrolled secondary hyperparathyroidism.