Reports describing significant health risks due to inadequate vitamin D status continue to generate considerable interest amongst the medical and lay communities alike. Recent research on the various molecular activities of the vitamin D system, including the nuclear vitamin D receptor and other receptors for 1,25-dihydroxyvitamin D and vitamin D metabolism, provides evidence that the vitamin D system carries out biological activities across a wide range of tissues similar to other nuclear receptor hormones. This knowledge provides physiological plausibility of the various health benefits claimed to be provided by vitamin D and supports the proposals for conducting clinical trials. The vitamin D system plays critical roles in the maintenance of plasma calcium and phosphate and bone mineral homeostasis. Recent evidence confirms that plasma calcium homeostasis is the critical factor modulating vitamin D activity. Vitamin D activities in the skeleton include stimulation or inhibition of bone resorption and inhibition or stimulation of bone formation. The three major bone cell types, which are osteoblasts, osteocytes and osteoclasts, can all respond to vitamin D via the classical nuclear vitamin D receptor and metabolize 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D to activate the vitamin D receptor and modulate gene expression. Dietary calcium intake interacts with vitamin D metabolism at both the renal and bone tissue levels to direct either a catabolic action on the bone through the endocrine system when calcium intake is inadequate or an anabolic action through a bone autocrine or paracrine system when calcium intake is sufficient.
Calcium/metabolism ; Fractures, Bone/metabolism/pathology ; Humans ; Osteoporosis/metabolism/pathology ; Protein Binding ; Receptors, Calcitriol/genetics/metabolism ; Vitamin D/analogs & derivatives/*metabolism

Osteopontin (OPN) is an acidic, noncollagenous matrix protein produced by the bone and kidneys. It is reportedly involved in bone resorption and formation. We examined the association between serum OPN levels and bone mineral density in postmenopausal women. Premenopausal women (n=32) and postmenopausal women (n=409) participated in the study. We measured serum osteopontin levels and their relationships with bone mineral density and previous total fragility fractures. The postmenopausal women had higher mean serum OPN levels compared to the premenopausal women (43.6+/-25.9 vs 26.3+/-18.6 ng/mL; P<0.001). In the postmenopausal women, high serum OPN levels were negatively correlated with mean lumbar bone mineral density (BMD) (r=-0.113, P=0.023). In a stepwise multiple linear regression model, serum OPN levels were associated with BMD of the spine, femoral neck, and total hip after adjustment for age, body mass index, smoking, and physical activity in postmenopausal women. However, serum OPN levels did not differ between postmenopausal women with and without fractures. Postmenopausal women exhibit higher serum OPN levels than premenopausal women and higher serum OPN levels were associated with low BMD in postmenopausal women.
Aged ; Bone Density/*physiology ; Female ; Femur Neck/metabolism ; Fractures, Bone/metabolism/pathology ; Humans ; Linear Models ; Middle Aged ; Osteopontin/*blood ; Postmenopause ; Premenopause ; Spine/metabolism

OBJECTIVES: To test whether myocardial apoptosis can be induced by traumatic fracture of lower limbs with hemorrhage, in order to lay a foundation of myocardial injury after traumatic fracture for the follow-up study. METHODS: Twenty SD rats were randomly divided into two groups, i. e. control group and trauma group(=10). A rat model of traumatic hemorrhage was establish, and a traumatic model of the original generation of myocardial cell culture was constructed . The level of interleukin-2(IL-2),IL-6,IL-10 and tumor necrosis factor-α(TNF-α) in rat serum was detected by ELISA at 0, 1, 2, 4, 8, 12, 16, 24 and 48 hour to find the most significant point. The pathological cardiac injury in rats was observed by HE staining under a microscope, and the apoptosis of cultured cardiomyocyte was detected by TUNEL methods. The expressions of apoptosis gene,(Bcl-2) and Bax, in myocardium of rat and cultured cardiomyocyte were detected by Western blot and RT-PCR. RESULTS: At the 4 hour after trauma, IL-6 and IL-10 in the serum of rats reached its highest, IL-2 reached its lowest at the 8th hour after trauma, and TNF-αreached its highest at 1 hour after trauma, then all recovered to their normol level gradually. Myocardial HE staining indicated that cardiomyocyte was swelling, disordered derangement, inflammatory cell infiltrated; a large number of myocardial cell nuclei was dyedbrown in TUNEL test which proved that the apoptosis index increased (<0.05). Western blot and RT-PCR results showed that the expression of pro-apoptotic gene Bax was up-regulated (<0. 05), while expression of anti apoptosis gene Bcl-2 down-regulated (<0.05). CONCLUSIONS The myocardial apoptosis can be induced by traumatic fracture of lower limbs with hemorrhage in rats, and then lead to myocardial injury.
Animals ; Apoptosis ; Cells, Cultured ; Cytokines ; blood ; Follow-Up Studies ; Fractures, Bone ; complications ; Hemorrhage ; complications ; Lower Extremity ; pathology ; Myocardium ; pathology ; Myocytes, Cardiac ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo observe the effect of acupuncture on fracture in the ovariectomized rat and the mechanism.

METHODSSixty SD female rats were randomly divided into 4 groups: normal group (group A), model group (group B), acupuncture group (group C) and Nilestriol group (group D). In all the groups, except the group A which received sham operation, the rats were overiectomized for preparing the osteoporosis model. Three months after the ovariectomy, the left femurs of the rats were closely fractured. Then, the group A and B were treated with oral administration of normal saline solution, 3 mL, weekly. The rats in the group C were treated daily with acupuncture at "Huantiao"(GB 30), "Housanli" (ST 36), "Yanglingquan"(GB 34) and "Weizhong"(BL 40) on the left hind legs; the rats in the group D were given orally Nilestriol solution (0.2 mg/mL) in a dose of 0.6 mL/100 g body weight, weekly. At the 7th, 14th, 21st and 28th days, some rats were sacrificed and their fractural callus and blood samples were taken for histological examinations and immunohistochemical examination of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB).

RESULTSHE stained callus slides observed by optical microscope showed that the process of fracture healing in the group A, C, D was faster than that in the group B. Positive immuno-stalning of BDNF and TrkB could be seen in the all groups, mainly on the 7 and 14 days after the fracture. The expression levels from high to low in turn were group A, C, D and B.

CONCLUSIONExpressions of BDNF and TrkB in callus of osteoporotic fracture were less than that of the normal fracture; acupuncture can elevate the expression levels and accelerate the process of fracture healing.

Acupuncture Therapy ; methods ; Animals ; Bony Callus ; metabolism ; pathology ; Brain-Derived Neurotrophic Factor ; biosynthesis ; Estriol ; administration & dosage ; analogs & derivatives ; therapeutic use ; Female ; Fractures, Bone ; etiology ; therapy ; Immunohistochemistry ; Ovariectomy ; adverse effects ; Quinestrol ; analogs & derivatives ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor, trkB ; metabolism ; Treatment Outcome