Correction to: Effects of growth hormone on bone modeling and remodeling in hypophysectomised young female rats: a bone histomorphometric study.

The following corrections are found in the original publication of the article and corrected as below.

Correction: Differential effects of growth hormone and alfa calcidol on trabecular and cortical bones in hypophysectomized rats.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Retraction: Response of cortical and cancellous bones to mild calcium deficiency in young growing female rats: a bone histomorphometry study.

The following articles have been retracted by the Editorial Board of Experimental Animals, because some parts of their contents were published elsewhere.

Retraction: Preventive effects of risedronate and calcitriol on cancellous osteopenia in rats treated with high-dose glucocorticoid.

The following articles have been retracted by the Editorial Board of Experimental Animals, because some parts of their contents were published elsewhere.

Retraction: Additive effect of vitamin K2 and risedronate on long bone mass in hypophysectomized young rats.

The following articles have been retracted by the Editorial Board of Experimental Animals, because some parts of their contents were published elsewhere.

Retraction: Therapeutic effect of risedronate on cancellous and cortical bone in ovariectomized osteopenic rats: a comparison with the effects of alfacalcidol.

The following articles have been retracted by the Editorial Board of Experimental Animals, because some parts of their contents were published elsewhere.

Retraction: Comparative effects of alendronate and alfacalcidol on cancellous and cortical bone mass and bone mechanical properties in ovariectomized rats.

The following articles have been retracted by the Editorial Board of Experimental Animals, because some parts of their contents were published elsewhere.

Retraction: Effect of pre- and post-surgery treatment with risedronate on trabecular bone loss in ovariectomized rats.

The following articles have been retracted by the Editorial Board of Experimental Animals, because some parts of their contents were published elsewhere.

Calcium and vitamin d supplementation in postmenopausal women.

CONTEXT: Bone health is influenced by the intake of both calcium and vitamin D. OBJECTIVE: Our objective was to evaluate the influence of calcium and vitamin D supplementation on PTH and bone turnover. SETTING, PATIENTS, AND DESIGN: At an ambulatory research center, 159 postmenopausal healthy white women participated in this double-blind, placebo-controlled parallel, longitudinal factorial study that was 6 months in duration. INTERVENTIONS: Subjects were randomly allocated to 4 groups: 1) double placebo, 2) calcium (1200 mg daily) plus placebo, 3) vitamin D3 (100 µg) plus placebo, and 4) vitamin D3 and calcium. Serum and urine were collected fasting and 2 hours after a calcium load at baseline and at 3 and 6 months. MAIN OUTCOME MEASURES: Serum PTH, cross-linked C-telopeptide (CTX), and procollagen type I N-terminal propeptide (P1NP) were measured. RESULTS: Before study medication, a calcium load resulted in a decline in PTH and CTX and an increase in urinary calcium excretion. Serum CTX and P1NP declined over time with calcium supplementation but did not change with increased vitamin D intake. There was a decline in PTH in the vitamin D groups in the fasting state compared with placebo. Suppression of PTH was greater after a calcium load in the vitamin D groups. A calcium load decreased PTH and CTX and raised urinary calcium. CONCLUSIONS: Fasting PTH declines with vitamin D supplementation. PTH declines after calcium intake. Supplementation of the diet with 1200 mg calcium/d reduces bone turnover markers, whereas supplementation with up to100 µg vitamin D3/d does not.

Green tea polyphenols improve bone microarchitecture in high-fat-diet-induced obese female rats through suppressing bone formation and erosion.

This study evaluates the effects of green tea polyphenols (GTPs) on bone microarchitecture in high-fat-diet (HFD)-induced obese female rats. Thirty-six 3-month-old female rats were fed either a control diet or a HFD for 4 months. Animals in the control group continued on the control diet for another 4 months. Animals in the HFD group were divided into two groups, with 0.5 g/100 mL GTP (the HFD+GTP group) or without GTP (the HFD group) in drinking water, in addition to the HFD for another 4 months. Compared to the control group, the HFD group increased bone formation and erosion rates at the tibia, decreased trabecular volume and thickness, but had no impact on bone mineral density (BMD), trabecular number (Tb.N), and separation. Compared to the control group, the HFD+GTP group demonstrates a greater Tb.N at the proximal tibia, and a greater trabecular thickness at the femur and the lumbar vertebrae, but a smaller trabecular separation (Tb.Sp) and mineralizing surface at the proximal tibia, and a reduced endocortical mineral apposition rate (MAR) at the tibia shaft. Relative to the HFD group, the HFD+GTP group demonstrates (1) a higher BMD at the femur, a greater trabecular volume, thickness, and number at the proximal tibia, a larger cortical area and thickness at the tibial shaft, and a greater trabecular volume and thickness at the femur and the lumbar vertebrae, (2) a smaller Tb.Sp, MAR, bone formation rate, and eroded surface at the tibia. We concluded that GTP supplementation in drinking water improves bone microarchitecture in the HFD-induced obese female rats, possibly through suppressing bone turnover, resulting in a larger net bone volume.

25-hydroxyvitamin D levels in African American and Nigerian women.

OBJECTIVES: African Americans (AA) have substantially lower levels of circulating 25-hydroxyvitamin D (25(OH)D) than whites. We compared population-based samples of 25(OH)D in women of African descent from Nigeria and metropolitan Chicago. METHODS: One hundred women of Yoruba ethnicity from southwest Nigeria and 94 African American women from metropolitan Chicago were recruited and compared using a standardized survey protocol and the same laboratory assay for 25(OH)D. RESULTS: Mean 25(OH)D levels were 64 nmol/l among the Nigerians and 29 nmol/l among the AA. Only 10% of the values were shared in common between the groups, and 76% of the Nigerians were above the currently defined threshold for adequate circulating 25(OH)D compared to 5% of the AA. Modest associations were seen between 25(OH)D and measures of obesity, although adjustment for these traits did not materially affect the group differences. CONCLUSION: These data support the presumption that skin color is an adaptive trait which has evolved in part to regulate 25(OH)D. It remains undetermined, however, whether lower values observed in AA have negative health consequences.

Green tea polyphenols benefits body composition and improves bone quality in long-term high-fat diet-induced obese rats.

This study investigates the effects of green tea polyphenols (GTPs) on body composition and bone properties along with mechanisms in obese female rats. Thirty-six 3-month-old Sprague Dawley female rats were fed either a low-fat (LF) or a high-fat (HF) diet for 4 months. Animals in the LF diet group continued on an LF diet for additional 4 months, whereas those in the HF diet group were divided into 2 groups: with GTP (0.5%) or without in drinking water, in addition to an HF diet for another 4 months. Body composition, femur bone mass and strength, serum endocrine and proinflammatory cytokines, and liver glutathione peroxidase (GPX) protein expression were determined. We hypothesized that supplementation of GTP in drinking water would benefit body composition, enhance bone quality, and suppress obesity-related endocrines in HF diet-induced obese female rats and that such changes are related to an elevation of antioxidant capacity and a reduction of proinflammatory cytokine production. After 8 months, compared with the LF diet, the HF diet increased percentage of fat mass and serum insulin-like growth factor I and leptin levels; reduced percentage of fat-free mass, bone strength, and GPX protein expression; but had no effect on bone mineral density and serum adiponectin levels in the rats. Green tea polyphenol supplementation increased percentage of fat-free mass, bone mineral density and strength, and GPX protein expression and decreased percentage of fat mass, serum insulin-like growth factor I, leptin, adiponectin, and proinflammatory cytokines in the obese rats. This study shows that GTP supplementation benefited body composition and bone properties in obese rats possibly through enhancing antioxidant capacity and suppressing inflammation.

Complementary and alternative exercises for management of osteoarthritis.

Osteoarthritis (OA) is a chronic condition characterized by degeneration of cartilage and its underlying bone within a joint. With no cure currently available, the goals of treating OA are to alleviate pain, maintain, or improve joint mobility, increase the muscle strength of the joints, and minimize the disabling effects of the disease. Recent research has suggested that complementary and alternative medicine (CAM) exercises may improve OA symptoms. This paper covers CAM mind-body exercises-Tai Chi, qigong, and yoga-for OA management and evaluates their benefits in pain reduction, muscle strength, physical function, stiffness, balance, fear of falling, self-efficacy, quality of life, and psychological outcomes in patients with OA, based on randomized controlled trials published. Findings from the literature suggest that CAM exercises demonstrate considerable promise in the management of OA. Future studies require rigorous randomized controlled trials with larger sample sizes.

Green tea and bone health: Evidence from laboratory studies.

Osteoporosis is a major health problem in the elderly. Epidemiological evidence has shown an association between tea consumption and the prevention of bone loss in the elderly population. Ingestion of green tea and green tea bioactive compounds may be beneficial in mitigating bone loss of this population and decreasing their risk of osteoporotic fractures. This review describes the effect of green tea with its bioactive components on bone health with an emphasis on the following: (i) the etiology of osteoporosis, (ii) evidence of osteo-protective impacts of green tea on bone mass and microarchitecture in various bone loss models in which induced by aging, sex hormone deficiency, and chronic inflammation, (iii) discussion of impacts of green tea on bone mass in two obesity models, (iv) observation of short-term green tea supplementation given to postmenopausal women with low bone mass, (v) possible mechanisms for the osteo-protective effects of green tea bioactive compounds, and (vi) a summary and future research direction of green tea and bone health.

Effect of vitamin K2 on cortical and cancellous bone mass and hepatic lipids in rats with combined methionine-choline deficiency.

The present study examined changes of cancellous and cortical bone in rats with combined methionine-choline deficiency (MCD). In addition, the effects of vitamin K2 on cortical and cancellous bone mass and hepatic lipids were investigated in rats with MCD. Six-week-old male Sprague-Dawley rats were randomized into three groups of ten, including an age-matched control (standard diet) group, an MCD diet group, and an MCD diet+vitamin K2 (menatetrenone at 30mg/kg/d orally, 5 times a week) group. After the one-month experimental period, histomorphometric analysis was performed on cortical and cancellous bone from the tibial diaphysis and proximal metaphysis, respectively, while histological examination of the liver was performed after staining with hematoxylin and eosin and Oil Red O. MCD rats displayed weight loss, diffuse and centrilobular fatty changes of the liver, and a decrease of the cancellous bone volume per tissue volume (BV/TV) and percent cortical area (Ct Ar) as a result of decreased trabecular, periosteal, and endocortical bone formation along with increased trabecular and endocortical bone resorption. Administration of vitamin K2 to rats with MCD attenuated weight loss, accelerated the decrease of cancellous BV/TV due to an increase of bone remodeling, and ameliorated the decrease of percent Ct Ar by increasing periosteal and endocortical bone formation. Vitamin K2 administration also prevented MCD-induced diffuse fatty change of the liver. These findings suggest a beneficial effect of vitamin K2 on cortical bone mass and hepatic lipid metabolism in rats with MCD. The loss of cancellous bone mass could possibly have been due to re-distribution of minerals to cortical bone.

Supplementation with green tea polyphenols improves bone microstructure and quality in aged, orchidectomized rats.

Recent studies show that green tea polyphenols (GTPs) attenuate bone loss and microstructure deterioration in ovariectomized aged female rats, a model of postmenopausal osteoporosis. This study evaluated the efficacy of GTPs at mitigating bone loss and microstructure deterioration along with related mechanisms in androgen-deficient aged rats, a model of male osteoporosis. A 2 (sham vs. orchidectomy) × 2 (no GTP and 0.5% GTP in drinking water) factorial design was studied for 16 weeks using 40 aged male rats. An additional 10 rats (baseline group) were killed at the beginning of study to provide baseline parameters. There was no difference in femoral mineral density between baseline and the sham only group. Orchidectomy suppressed serum testosterone and tartrate-resistant acid phosphatase concentrations, liver glutathione peroxidase activity, bone mineral density, and bone strength. Orchidectomy also decreased trabecular bone volume, number, and thickness in the distal femur and proximal tibia and bone-formation rate in trabecular bone of proximal tibia but increased serum osteocalcin concentrations and bone-formation rates in the endocortical tibial shaft. GTP supplementation resulted in increased serum osteocalcin concentrations, bone mineral density, and trabecular volume, number, and strength of femur; increased trabecular volume and thickness and bone formation in both the proximal tibia and periosteal tibial shaft; decreased eroded surface in the proximal tibia and endocortical tibial shaft; and increased liver glutathione peroxidase activity. We conclude that GTP supplementation attenuates trabecular and cortical bone loss through increasing bone formation while suppressing bone resorption due to its antioxidant capacity.