Mechanical Loading Attenuates Radiation-Induced Bone Loss in Bone Marrow Transplanted Mice

Science.gov (United States)

Govey, Peter M.; Zhang, Yue; Donahue, Henry J.

2016-01-01

Exposure of bone to ionizing radiation, as occurs during radiotherapy for some localized malignancies and blood or bone marrow cancers, as well as during space travel, incites dose-dependent bone morbidity and increased fracture risk. Rapid trabecular and endosteal bone loss reflects acutely increased osteoclastic resorption as well as decreased bone formation due to depletion of osteoprogenitors. Because of this dysregulation of bone turnover, bone’s capacity to respond to a mechanical loading stimulus in the aftermath of irradiation is unknown. We employed a mouse model of total body irradiation and bone marrow transplantation simulating treatment of hematologic cancers, hypothesizing that compression loading would attenuate bone loss. Furthermore, we hypothesized that loading would upregulate donor cell presence in loaded tibias due to increased engraftment and proliferation. We lethally irradiated 16 female C57Bl/6J mice at age 16 wks with 10.75 Gy, then IV-injected 20 million GFP(+) total bone marrow cells. That same day, we initiated 3 wks compression loading (1200 cycles 5x/wk, 10 N) in the right tibia of 10 of these mice while 6 mice were irradiated, non-mechanically-loaded controls. As anticipated, before-and-after microCT scans demonstrated loss of trabecular bone (-48.2% Tb.BV/TV) and cortical thickness (-8.3%) at 3 wks following irradiation. However, loaded bones lost 31% less Tb.BV/TV and 8% less cortical thickness (both pbones also had significant increases in trabecular thickness and tissue mineral densities from baseline. Mechanical loading did not affect donor cell engraftment. Importantly, these results demonstrate that both cortical and trabecular bone exposed to high-dose therapeutic radiation remain capable of an anabolic response to mechanical loading. These findings inform our management of bone health in cases of radiation exposure. PMID:27936104

Secondary Hyperparathyroidism and Bone Turnover in Elderly with Bone Loss - Original Investigation

Directory of Open Access Journals (Sweden)

Nurdan Peker

2006-12-01

Full Text Available Bone loss is common in the elderly. Parathyroid hormone (PTH, which regulates serum calcium levels,calcitonin and vitamin D metabolites have various effects on skeletal system. The aim of this study was to assess secondary hyperparathyroidism (HPTH and bone turnover in elderly with bone loss. Fifty-five patients (9 men,46 women older than 65 years with bone loss were included in the study. Bone mineral density was measured by dual energy x-ray absorptiomety (DXA at L1-4 vertebrae and proximal femur regions. Patients with T scores <-1.5 at one of the measurement sites were included in the study. Study subjects were assessed in terms of fracture history, sunbathing and walking activity. Routine biochemical tests, serum osteocalcin (OC and C-telopeptide type 1 collagen (CTX and lateral thoracal and lumbar vertebrae radyographic evaluation was performed. Our results showed that 70.9% of the patients had HPTH. Total femur BMD values and femur neck T scores were significantly lower in HPTH group than PTH normal one (p=0.05, p=0.03. Serum OC and CTX levels were higher in both groups. There was a negative correlation with femur neck BMD and CTX (r=0,321. There was no correlation between serum PTH levels and lumbar vertebrae and proximal femur BMD values. Serum PTH and alkaline phosphatase levels showed a significant positive correlation. In conclusion secondary HPTH and increased bone turnover is common elderly with bone loss. Adequate calcium and vitamin D intake is important the older people. (Osteoporoz Dünyasından 2006; 12: 70-3

Bioactive silica nanoparticles reverse age-associated bone loss in mice.

Science.gov (United States)

Weitzmann, M Neale; Ha, Shin-Woo; Vikulina, Tatyana; Roser-Page, Susanne; Lee, Jin-Kyu; Beck, George R

2015-05-01

We recently reported that in vitro, engineered 50nm spherical silica nanoparticles promote the differentiation and activity of bone building osteoblasts but suppress bone-resorbing osteoclasts. Furthermore, these nanoparticles promote bone accretion in young mice in vivo. We have now investigated the capacity of these nanoparticles to reverse bone loss in aged mice, a model of human senile osteoporosis. Aged mice received nanoparticles weekly and bone mineral density (BMD), bone structure, and bone turnover were quantified. Our data revealed a significant increase in BMD, bone volume, and biochemical markers of bone formation. Biochemical and histological examinations failed to identify any abnormalities caused by nanoparticle administration. Our studies demonstrate that silica nanoparticles effectively blunt and reverse age-associated bone loss in mice by a mechanism involving promotion of bone formation. The data suggest that osteogenic silica nanoparticles may be a safe and effective therapeutic for counteracting age-associated bone loss. Osteoporosis poses a significant problem in the society. Based on their previous in-vitro findings, the authors' group investigated the effects of spherical silica nanoparticles in reversing bone loss in a mouse model of osteoporosis. The results showed that intra-peritoneal injections of silica nanoparticles could increase bone mineral density, with little observed toxic side effects. This novel method may prove important in future therapy for combating osteoporosis. Published by Elsevier Inc.

Glucocorticoid: A potential role in microgravity-induced bone loss

Science.gov (United States)

Yang, Jiancheng; Yang, Zhouqi; Li, Wenbin; Xue, Yanru; Xu, Huiyun; Li, Jingbao; Shang, Peng

2017-11-01

Exposure of animals and humans to conditions of microgravity, including actual spaceflight and simulated microgravity, results in numerous negative alterations to bone structure and mechanical properties. Although there are abundant researches on bone loss in microgravity, the explicit mechanism is not completely understood. At present, it is widely accepted that the absence of mechanical stimulus plays a predominant role in bone homeostasis disorders in conditions of weightlessness. However, aside from mechanical unloading, nonmechanical factors such as various hormones, cytokines, dietary nutrition, etc. are important as well in microgravity induced bone loss. The stress-induced increase in endogenous glucocorticoid (GC) levels is inevitable in microgravity environments. Moreover, it is well known that GCs have a detrimental effect to bone health at excess concentrations. Therefore, GC plays a potential role in microgravity-induced bone loss. This review summarizeds several studies and their prospective solutions to this hypothesis.

Probiotics protect mice from ovariectomy-induced cortical bone loss.

Science.gov (United States)

Ohlsson, Claes; Engdahl, Cecilia; Fåk, Frida; Andersson, Annica; Windahl, Sara H; Farman, Helen H; Movérare-Skrtic, Sofia; Islander, Ulrika; Sjögren, Klara

2014-01-01

The gut microbiota (GM) modulates the hosts metabolism and immune system. Probiotic bacteria are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host and can alter the composition of the GM. Germ-free mice have increased bone mass associated with reduced bone resorption indicating that the GM also regulates bone mass. Ovariectomy (ovx) results in bone loss associated with altered immune status. The purpose of this study was to determine if probiotic treatment protects mice from ovx-induced bone loss. Mice were treated with either a single Lactobacillus (L) strain, L. paracasei DSM13434 (L. para) or a mixture of three strains, L. paracasei DSM13434, L. plantarum DSM 15312 and DSM 15313 (L. mix) given in the drinking water during 6 weeks, starting two weeks before ovx. Both the L. para and the L. mix treatment protected mice from ovx-induced cortical bone loss and bone resorption. Cortical bone mineral content was higher in both L. para and L. mix treated ovx mice compared to vehicle (veh) treated ovx mice. Serum levels of the resorption marker C-terminal telopeptides and the urinary fractional excretion of calcium were increased by ovx in the veh treated but not in the L. para or the L. mix treated mice. Probiotic treatment reduced the expression of the two inflammatory cytokines, TNFα and IL-1β, and increased the expression of OPG, a potent inhibitor of osteoclastogenesis, in cortical bone of ovx mice. In addition, ovx decreased the frequency of regulatory T cells in bone marrow of veh treated but not probiotic treated mice. In conclusion, treatment with L. para or the L. mix prevents ovx-induced cortical bone loss. Our findings indicate that these probiotic treatments alter the immune status in bone resulting in attenuated bone resorption in ovx mice.

Probiotics protect mice from ovariectomy-induced cortical bone loss.

Directory of Open Access Journals (Sweden)

Claes Ohlsson

Full Text Available The gut microbiota (GM modulates the hosts metabolism and immune system. Probiotic bacteria are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host and can alter the composition of the GM. Germ-free mice have increased bone mass associated with reduced bone resorption indicating that the GM also regulates bone mass. Ovariectomy (ovx results in bone loss associated with altered immune status. The purpose of this study was to determine if probiotic treatment protects mice from ovx-induced bone loss. Mice were treated with either a single Lactobacillus (L strain, L. paracasei DSM13434 (L. para or a mixture of three strains, L. paracasei DSM13434, L. plantarum DSM 15312 and DSM 15313 (L. mix given in the drinking water during 6 weeks, starting two weeks before ovx. Both the L. para and the L. mix treatment protected mice from ovx-induced cortical bone loss and bone resorption. Cortical bone mineral content was higher in both L. para and L. mix treated ovx mice compared to vehicle (veh treated ovx mice. Serum levels of the resorption marker C-terminal telopeptides and the urinary fractional excretion of calcium were increased by ovx in the veh treated but not in the L. para or the L. mix treated mice. Probiotic treatment reduced the expression of the two inflammatory cytokines, TNFα and IL-1β, and increased the expression of OPG, a potent inhibitor of osteoclastogenesis, in cortical bone of ovx mice. In addition, ovx decreased the frequency of regulatory T cells in bone marrow of veh treated but not probiotic treated mice. In conclusion, treatment with L. para or the L. mix prevents ovx-induced cortical bone loss. Our findings indicate that these probiotic treatments alter the immune status in bone resulting in attenuated bone resorption in ovx mice.

Effects of Spaceflight on Bone: The Rat as an Animal Model for Human Bone Loss

Science.gov (United States)

Halloran, B.; Weider, T.; Morey-Holton, E.

1999-01-01

The loss of weight bearing during spaceflight results in osteopenia in humans. Decrements in bone mineral reach 3-10% after as little as 75-184 days in space. Loss of bone mineral during flight decreases bone strength and increases fracture risk. The mechanisms responsible for, and the factors contributing to, the changes in bone induced by spaceflight are poorly understood. The rat has been widely used as an animal model for human bone loss during spaceflight. Despite its potential usefulness, the results of bone studies performed in the rat in space have been inconsistent. In some flights bone formation is decreased and cancellous bone volume reduced, while in others no significant changes in bone occur. In June of 1996 Drs. T. Wronski, S. Miller and myself participated in a flight experiment (STS 78) to examine the effects of glucocorticoids on bone during weightlessness. Technically the 17 day flight experiment was flawless. The results, however, were surprising. Cancellous bone volume and osteoblast surface in the proximal tibial metaphysis were the same in flight and ground-based control rats. Normal levels of cancellous bone mass and bone formation were also detected in the lumbar vertebrae and femoral neck of flight rats. Furthermore, periosteal bone formation rate was found to be identical in flight and ground-based control rats. Spaceflight had little or no effect on bone metabolism! These results prompted us to carefully review the changes in bone observed in, and the flight conditions of previous spaceflight missions.

Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle

Directory of Open Access Journals (Sweden)

Fuli Zhu

2018-03-01

Full Text Available An irreversible Maisotsenko reciprocating Brayton cycle (MRBC model is established using the finite time thermodynamic (FTT theory and taking the heat transfer loss (HTL, piston friction loss (PFL, and internal irreversible losses (IILs into consideration in this paper. A calculation flowchart of the power output (P and efficiency (η of the cycle is provided, and the effects of the mass flow rate (MFR of the injection of water to the cycle and some other design parameters on the performance of cycle are analyzed by detailed numerical examples. Furthermore, the superiority of irreversible MRBC is verified as the cycle and is compared with the traditional irreversible reciprocating Brayton cycle (RBC. The results can provide certain theoretical guiding significance for the optimal design of practical Maisotsenko reciprocating gas turbine plants.

Cadmium accelerates bone loss in ovariectomized mice and fetal rat limb bones in culture

International Nuclear Information System (INIS)

Bhattacharyya, M.H.; Whelton, B.D.; Stern, P.H.; Peterson, D.P.

1988-01-01

Loss of bone mineral after ovariectomy was studied in mice exposed to dietary cadmium at 0.25, 5, or 50 ppm. Results show that dietary cadmium at 50 ppm increased bone mineral loss to a significantly greater extent in ovariectomized mice than in sham-operated controls. These results were obtained from two studies, one in which skeletal calcium content was determined 6 months after ovariectomy and a second in which 45 Ca release from 45 Ca-prelabeled bones was measured immediately after the start of dietary cadmium exposure. Furthermore, experiments with 45 Ca-prelabeled fetal rat limb bones in culture demonstrated that Cd at 10 nM in the medium, a concentration estimated to be in the plasma of mice exposed to 50 ppm dietary Cd, strikingly increased bone resorption. These in vitro results indicate that cadmium may enhance bone mineral loss by a direct action on bone. Results of the in vivo studies are consistent with a significant role of cadmium in the etiology of Itai-Itai disease among postmenopausal women in Japan and may in part explain the increased risk of postmenopausal osteoporosis among women who smoke

Room temperature housing results in premature cancellous bone loss in growing female mice: implications for the mouse as a preclinical model for age-related bone loss.

Science.gov (United States)

Iwaniec, U T; Philbrick, K A; Wong, C P; Gordon, J L; Kahler-Quesada, A M; Olson, D A; Branscum, A J; Sargent, J L; DeMambro, V E; Rosen, C J; Turner, R T

2016-10-01

Room temperature housing (22 °C) results in premature cancellous bone loss in female mice. The bone loss was prevented by housing mice at thermoneutral temperature (32 °C). Thermogenesis differs markedly between mice and humans and mild cold stress induced by standard room temperature housing may introduce an unrecognized confounding variable into preclinical studies. Female mice are often used as preclinical models for osteoporosis but, in contrast to humans, mice exhibit cancellous bone loss during growth. Mice are routinely housed at room temperature (18-23 °C), a strategy that exaggerates physiological differences in thermoregulation between mice (obligatory daily heterotherms) and humans (homeotherms). The purpose of this investigation was to assess whether housing female mice at thermoneutral (temperature range where the basal rate of energy production is at equilibrium with heat loss) alters bone growth, turnover and microarchitecture. Growing (4-week-old) female C57BL/6J and C3H/HeJ mice were housed at either 22 or 32 °C for up to 18 weeks. C57BL/6J mice housed at 22 °C experienced a 62 % cancellous bone loss from the distal femur metaphysis during the interval from 8 to 18 weeks of age and lesser bone loss from the distal femur epiphysis, whereas cancellous and cortical bone mass in 32 °C-housed mice were unchanged or increased. The impact of thermoneutral housing on cancellous bone was not limited to C57BL/6J mice as C3H/HeJ mice exhibited a similar skeletal response. The beneficial effects of thermoneutral housing on cancellous bone were associated with decreased Ucp1 gene expression in brown adipose tissue, increased bone marrow adiposity, higher rates of bone formation, higher expression levels of osteogenic genes and locally decreased bone resorption. Housing female mice at 22 °C resulted in premature cancellous bone loss. Failure to account for species differences in thermoregulation may seriously confound interpretation of studies

The estrogen-related receptors (ERRs): potential targets against bone loss.

Science.gov (United States)

Zhang, Ling; Wong, Jiemin; Vanacker, Jean-Marc

2016-10-01

Bone loss and the resulting skeletal fragility is induced by several pathological or natural conditions, the most prominent of which being aging as well as the decreased levels of circulating estrogens in post-menopause females. To date, most treatments against bone loss aim at preventing excess bone resorption. We here summarize data indicating that the estrogen-related receptors (ERRs) α and γ prevent bone formation. Inhibiting these receptors may thus constitute an anabolic approach by increasing bone formation.

DLK1 is a novel regulator of bone mass that mediates estrogen deficiency-induced bone loss in mice

DEFF Research Database (Denmark)

Abdallah, Basem M; Ditzel, Nicholas; Mahmood, Amer

2011-01-01

. In a number of in vitro culture systems, Dlk1 stimulated osteoclastogenesis indirectly through osteoblast-dependent increased production of proinflammatory bone-resorbing cytokines (eg, Il7, Tnfa, and Ccl3). We found that ovariectomy (ovx)-induced bone loss was associated with increased production of Dlk1...... in the bone marrow by activated T cells. Interestingly, Dlk1(-/-) mice were significantly protected from ovx-induced bone loss compared with wild-type mice. Thus we identified Dlk1 as a novel regulator of bone mass that functions to inhibit bone formation and to stimulate bone resorption. Increasing DLK1...... production by T cells under estrogen deficiency suggests its possible use as a therapeutic target for preventing postmenopausal bone loss....

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

2000-01-01

... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

1999-01-01

... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

2001-01-01

... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wacawski-Wende, Jean

1997-01-01

... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

1998-01-01

... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

Exergetic efficiency optimization for an irreversible heat pump ...

Indian Academy of Sciences (India)

side ... For irreversible cycle, the internal irreversibility, i.e., non-isentropic losses in the ... constant thermal capacitance rate (the product of mass flow rate and specific heat), .... reversed Brayton cycle is dependent on the external heat transfer ...

Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

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Tae-Ho Kim

2016-01-01

Full Text Available Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr cocoons spun by Rhus javanica (Bell. Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr or 100% ethanolic extract (eeGr on ovariectomy- (OVX- induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks augmented the inhibition of femoral bone mineral density (BMD, bone mineral content (BMC, and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.

Metaphyseal bone loss demonstrated with routine planar radiography

International Nuclear Information System (INIS)

Mintzer, C.M.; Robertson, D.D.; Weissman, B.; Ewald, F.; Spector, M.

1989-01-01

This paper reports on an vitro study performed to examine the ability of current-day radiography for detecting metaphyseal bone loss. A block was cut from the anterior aspect of a cadaveric distal femur, sequential sections (approximately 4% of the BMC of the block) were cut from the block, and a fat-equivalent material was substituted in to the void. Following removal of each bone section, the femur was placed in a water bath, a lateral radiography was taken, and the ash content of the section was determined. Five readers each evaluated over 100 combinations of two radiographs side by side, noting whether there was no difference or whether one femur's region of interest was denser. The readings were compared with bone mineral differences as determined by ashing. All readers identified losses of 25% or more, and 5%-10% losses were seen by four of five readers half of the time

Marginal Bone Loss after Ten Years in an Adult Danish Population: A Radiographic Study.

Science.gov (United States)

Bahrami, Golnosh; Vaeth, Michael; Wenzel, Ann; Isidor, Flemming

To evaluate marginal bone loss over a 10-year period in individuals and in tooth groups in relation to age and level of marginal bone. In 1997, 616 randomly selected individuals (mean age: 42 years, range: 21-63 years) underwent a full-mouth radiographic survey. In 2008, the survey was repeated in 362 of the same individuals (182 women and 180 men). The marginal bone level of each tooth was measured in mm from the cementoenamel junction to the marginal bone. These measurements were used to calculate marginal bone loss during the 10-year period for individuals and tooth groups in relation to age and to baseline marginal bone level, calculated as the average between measurements in 1997 and 2008 to circumvent regression towards the mean. The average annual marginal bone loss was 0.09 mm (SD ± 0.04 mm) during the 10-year study period. The association between marginal bone loss and baseline marginal bone level was more pronounced in the youngest age group, compared to the other age groups. Molars displayed the most severe bone loss during the study period. Marginal bone loss over a 10-year period is associated with age and baseline marginal bone level. Younger individuals with a reduced marginal bone level were at higher risk for further bone loss. Molars lose marginal bone more rapidly than other tooth groups.

Proximal alveolar bone loss in a longitudinal radiographic investigation

International Nuclear Information System (INIS)

Bolin, A.; Lavstedt, S.; Henrikson, C.O.; Frithiof, L.

1986-01-01

In Sweden people in all age groups now have more remaining teeth than previosly. An investigation has been made to identify some predictors of alveolar bone loss in a 10-year period in subjects with at least 20 remaining teeth. The material consisted of 349 individuals, examined radiographically, clinically and by interview in 1970 and in 1980. These subjects, born in 1904-1952, constituted a subgroup, with regard to remaining teeth, of an unselected sample of the population of the old county of Stockholm. In the unselected sample statistically significant predictors of alveolar bone loss found in a stepwise multiple regression analysis were 1) alveolar bone loss in 1970, 2) age, 3) number of lost teeth and 4) Russell's Periodontol Index (PI). In the subgroup the predictors were in the order 1) Russell's PI and 2) smoking. The prediction values (R 2 ) of further variables were marginal. The analyses showed that there was an interaction between PI and smoking, implying that the effect of smoking on alveolar bone loss was increased in individuals with high PI values. Furthermore, a tendency was found for a dose-response effect of tobacco consumption. This tendency almost disappeared when controlling for PI

RANK, RANKL and osteoprotegerin in arthritic bone loss

Directory of Open Access Journals (Sweden)

M.C. Bezerra

2005-02-01

Full Text Available Rheumatoid arthritis is characterized by the presence of inflammatory synovitis and destruction of joint cartilage and bone. Tissue proteinases released by synovia, chondrocytes and pannus can cause cartilage destruction and cytokine-activated osteoclasts have been implicated in bone erosions. Rheumatoid arthritis synovial tissues produce a variety of cytokines and growth factors that induce monocyte differentiation to osteoclasts and their proliferation, activation and longer survival in tissues. More recently, a major role in bone erosion has been attributed to the receptor activator of nuclear factor kappa B ligand (RANKL released by activated lymphocytes and osteoblasts. In fact, osteoclasts are markedly activated after RANKL binding to the cognate RANK expressed on the surface of these cells. RANKL expression can be upregulated by bone-resorbing factors such as glucocorticoids, vitamin D3, interleukin 1 (IL-1, IL-6, IL-11, IL-17, tumor necrosis factor-alpha, prostaglandin E2, or parathyroid hormone-related peptide. Supporting this idea, inhibition of RANKL by osteoprotegerin, a natural soluble RANKL receptor, prevents bone loss in experimental models. Tumor growth factor-ß released from bone during active bone resorption has been suggested as one feedback mechanism for upregulating osteoprotegerin and estrogen can increase its production on osteoblasts. Modulation of these systems provides the opportunity to inhibit bone loss and deformity in chronic arthritis.

Cortical bone mineral content in primary hyperparathyroidism

International Nuclear Information System (INIS)

Mautalen, C.; Reyes, H.R.; Ghiringhelli, G.; Fromm, G.

1986-01-01

The bone mineral content (BMC) of 35 patients with primary hyperparathyroidism (PHPT) was measured at the mid radius (95% cortical bone) by photon absorptiometry of a 241 Am source. The majority of the patients had an overt disease of moderate to severe degree. Average serum calcium of the group was 12.3 mg/100 ml (range 10.6 to 18.0 mg/100 ml). The percentage of normality of the BMC was (Av +- 1 SD) 75.1 +- 13.0% for the whole group. The average increment of BMC in 14 patients 9 to 26 months after parathyroidectomy was 9.9%, with a wide dispersion. However, a highly significant negative correlation (r: 0.83; P < 0.01) was found between the initial bone mass and the percentage increment per month after surgery. No furhter gain was observed 2 years after parathyroidectomy except in one patient with an extremely severe bone loss. In spite of the gain obtained after surgery the bone mass remained markedly diminished in most patients showing that the cortical bone loss caused by PHPT is mainly irreversible. (author)

Bone loss in long-term suppressive therapy with thyroid hormone

International Nuclear Information System (INIS)

Firooznia, H.; Blum, M.; Golimbu, C.; Rafii, M.

1987-01-01

The trabecular bone density of the spine was measured with CT in 31 women, aged 39-79 years, who had received an average of 13.5 years of thyroid suppressive therapy. The spinal trabecular bone density values in 24 (77%), 18 (58%), and 13 subjects (42%) were respectively below the mean for healthy age-matched controls, the fifth percentile for healthy premenopausal women, and the fifth percentile for age-matched controls. Cortical and trabecular bone loss occurs in hyperthyroidism. Although the intent is not to cause hyperthyroidism in subjects on suppressive therapy, supraphysical doses of thyroid hormone are usually necessary for suppression of thyroid-stimulating hormone. In this study, bone loss was noted in these subjects. Because most of these patients are middle-aged or postmenopausal women, who are at risk for osteoporosis, it is important to be aware of the risk of additional bone loss induced by thyroid suppressive therapy in them

Unravelling the origin of irreversible capacity loss in NaNiO 2 for high voltage sodium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Wang, Liguang; Wang, Jiajun; Zhang, Xiaoyi; Ren, Yang; Zuo, Pengjian; Yin, Geping; Wang, Jun

2017-04-01

Layered transition metal compounds have attracted much attention due to their high theoretical capacity and energy density for sodium ion batteries. However, this kind of material suffers from serious irreversible capacity decay during the charge and discharge process. Here, using synchrotron-based operando transmission X-ray microscopy and high-energy X-ray diffraction combined with electrochemical measurements, the visualization of the dissymmetric phase transformation and structure evolution mechanism of layered NaNiO2 material during initial charge and discharge cycles are clarified. Phase transformation and deformation of NaNiO2 during the voltage range of below 3.0 V and over 4.0 V are responsible for the irreversible capacity loss during the first cycling, which is also confirmed by the evolution of reaction kinetics behavior obtained by the galvanostatic intermittent titration technique. These findings reveal the origin of the irreversibility of NaNiO2 and offer valuable insight into the phase transformation mechanism, which will provide underlying guidance for further development of high-performance sodium ion batteries.

Analysis of a compartmental model of amyloid beta production, irreversible loss and exchange in humans.

Science.gov (United States)

Elbert, Donald L; Patterson, Bruce W; Bateman, Randall J

2015-03-01

Amyloid beta (Aβ) peptides, and in particular Aβ42, are found in senile plaques associated with Alzheimer's disease. A compartmental model of Aβ production, exchange and irreversible loss was recently developed to explain the kinetics of isotope-labeling of Aβ peptides collected in cerebrospinal fluid (CSF) following infusion of stable isotope-labeled leucine in humans. The compartmental model allowed calculation of the rates of production, irreversible loss (or turnover) and short-term exchange of Aβ peptides. Exchange of Aβ42 was particularly pronounced in amyloid plaque-bearing participants. In the current work, we describe in much greater detail the characteristics of the compartmental model to two distinct audiences: physician-scientists and biokineticists. For physician-scientists, we describe through examples the types of questions the model can and cannot answer, as well as correct some misunderstandings of previous kinetic analyses applied to this type of isotope labeling data. For biokineticists, we perform a system identifiability analysis and a sensitivity analysis of the kinetic model to explore the global and local properties of the model. Combined, these analyses motivate simplifications from a more comprehensive physiological model to the final model that was previously presented. The analyses clearly demonstrate that the current dataset and compartmental model allow determination with confidence a single 'turnover' parameter, a single 'exchange' parameter and a single 'delay' parameter. When combined with CSF concentration data for the Aβ peptides, production rates may also be obtained. Copyright © 2015 Elsevier Inc. All rights reserved.

Bone Loss During Spaceflight: Available Models and Counter-Measures

Science.gov (United States)

Morris, Jonathan; Bach, David; Geller, David

2015-01-01

There is ongoing concern for human health during spaceflights. Of particular interest is the uncoupling of bone remodeling and its resultant effect on calcium metabolism and bone loss. The calculated average loss of bone mineral density (BMD) is approximately 1-1.5% per month of spaceflight. The effect of decreased BMD on associated fractures in astronauts is not known. Currently on the International Space Station (ISS), bone loss is managed through dietary supplements and modifications and resistance exercise regimen. As the duration of space flights increases, a review of the current methods available for the prevention of bone loss is warranted. The goal of this project is to review and summarize recent studies that have focused on maintaining BMD during exposure to microgravity. Interventions were divided into physical (Table 1), nutritional (Table 2), or pharmacologic (Table 3) categories. Physical modalities included resistance exercise, low level vibration, and low intensity pulsed ultrasound. Nutritional interventions included altering protein, salt, and fat intake; and vitamin D supplementation. Pharmacologic interventions included the use of bisphosphonates and beta blockers. Studies reported outcomes based on bone density determined by DXA bone scan, micro-architecture of histology and microCT, and serum and urine markers of bone turnover. The ground analog models utilized to approximate osseous physiology in microgravity included human patients previously paralyzed or subjects confined to bedrest. Ground analog animal models include paralysis, immobilization and ovariectomies. As a result of the extensive research performed there is a multi-modality approach available for the management of BMD during spaceflight that includes resistance training, nutrition and dietary supplements. However, there is a paucity of literature describing a formalized tiered protocol to guide investigators through the progression from animal models to human patient ground

A radiographic study of alveolar bone loss in Irish schoolchildren

International Nuclear Information System (INIS)

Buckley, L.A.

1982-01-01

Bitewing radiographs were used to assess evidence of alveolar bone loss in 1492 children in the age range 7-12 years. According to the method used in this study, alveolar bone loss was shown to occur in 1.7% of the children, and maxillary teeth were affected twice as frequently as mandibular teeth. (Author)

Does platform switching really prevent crestal bone loss around implants?

Directory of Open Access Journals (Sweden)

Yoshiyuki Hagiwara

2010-08-01

Full Text Available To maintain long-term implant stability, it is important to minimize bone loss around the implant. Several clinical studies have shown a mean marginal bone loss around dental implants of 1.5–2 mm in the first year after prosthetic restoration. Currently, concepts to prevent bone loss around dental implants have been reported as the platform switching (PLS. This technique use of prosthetic abutments with reduced width in relation to the implant platform diameter seems to have the greatest potential to limit the crestal resorption. However, there are only a few reports on the mechanism of action or the extent of bone loss prevention, and as such, it is difficult to say that the effect of PLS has been thoroughly examined. Excluding case reports, articles on PLS can be broadly categorized into: (1 radiographic evaluation of crestal bone level in humans, (2 histological and histomorphometrical analysis in animals, or (3 finite element analysis. This review revealed a shortage of published data for above three categories related PLS. Researchers have attempted to explain the mechanism of action of PLS; however, it is necessary to conduct further studies, including histological studies using animals, to clarify the mechanism fully.

Biglycan deficiency interferes with ovariectomy-induced bone loss

DEFF Research Database (Denmark)

Nielsen, Karina L; Allen, Matthew R; Bloomfield, Susan A

2003-01-01

Biglycan is a matrix proteoglycan with a possible role in bone turnover. In a 4-week study with sham-operated or OVX biglycan-deficient or wildtype mice, we show that biglycan-deficient mice are resistant to OVX-induced trabecular bone loss and that there is a gender difference in the response...

Structural joint damage and hand bone loss in patients with rheumatoid arthritis.

Science.gov (United States)

Lykke, Midtbøll Ørnbjerg

2018-03-01

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by pain, swelling and progressive destruction of the joints leading to loss of function and invalidity. The bone destruction in RA is characterised by two distinct features: structural joint damage and hand bone loss, and their prevention is an important treatment goal. Inhibitors of tumour necrosis factor alpha (TNF-inhibitors) have markedly improved the treatment options in RA patients who fail treatment with conventional synthetic Disease Modifying Anti Rheumatic Drugs (sDMARDS), but their effectiveness with regards to structural joint damage and hand bone loss, predictors thereof and the association with disease activity during treatment have mainly been investigated in randomized controlled trials (RCTs) with limited generalizability due to strict in- and exclusion criteria.
 The main aim of the PhD thesis was to assess and predict structural joint damage and hand bone loss in patients with early and established RA treated with sDMARDs and TNF-inhibitors. This was investigated in two cohorts: A) The "DANBIO X-ray study": an observational, nationwide, longitudinal cohort study of established RA patients treated in clinical practice who initiated TNF-inhibitor treatment after failure of sDMARDs and B) The "OPERA study": a randomized controlled trial of sDMARD-naïve patients with early RA treated with methotrexate (MTX) and intraarticular glucocorticoid injections in combination with adalimumab or placebo-adalimumab. Structural joint damage progression was assessed with the Sharp/van der Heijde radiographic method and hand bone loss was assessed with Digital X-ray Radiogrammetry. 
From the studies presented in the PhD thesis the following was concluded:
 Structural joint damage progression and hand bone loss were significantly lower during two years of TNF-inhibitor treatment compared to the previous two years of sDMARD-treatment in the DANBIO X-ray Study. The majority of patients had

Vitamin C reverses hypogonadal bone loss

Science.gov (United States)

Epidemiologic studies correlate low vitamin C intake with bone loss. The genetic deletion of enzymes involved in de novo vitamin C synthesis in mice, likewise, causes severe osteoporosis. However, very few studies have evaluated a protective role of this dietary supplement on the skeleton. Here, ...

Effect of dietary soy isoflavones on bone loss in ovariectomized rats

African Journals Online (AJOL)

Abstract. Purpose: To determine the effect of dietary soy isoflavone supplementation on bone loss in ... Keywords: Mineral elements, Alkaline phosphatase, Isoflavones, Bone loss, Notch pathway. This is an Open .... incubated for 3 h in 5% non-fat-milk blocking solution at ..... protect against osteopenia in ovariectomised rats.

Kit W-sh Mutation Prevents Cancellous Bone Loss during Calcium Deprivation.

Science.gov (United States)

Lotinun, Sutada; Suwanwela, Jaijam; Poolthong, Suchit; Baron, Roland

2018-01-01

Calcium is essential for normal bone growth and development. Inadequate calcium intake increases the risk of osteoporosis and fractures. Kit ligand/c-Kit signaling plays an important role in regulating bone homeostasis. Mice with c-Kit mutations are osteopenic. The present study aimed to investigate whether impairment of or reduction in c-Kit signaling affects bone turnover during calcium deprivation. Three-week-old male WBB6F1/J-Kit W /Kit W-v /J (W/W v ) mice with c-Kit point mutation, Kit W-sh /HNihrJaeBsmJ (W sh /W sh ) mice with an inversion mutation in the regulatory elements upstream of the c-Kit promoter region, and their wild-type controls (WT) were fed either a normal (0.6% calcium) or a low calcium diet (0.02% calcium) for 3 weeks. μCT analysis indicated that both mutants fed normal calcium diet had significantly decreased cortical thickness and cancellous bone volume compared to WT. The low calcium diet resulted in a comparable reduction in cortical bone volume and cortical thickness in the W/W v and W sh /W sh mice, and their corresponding controls. As expected, the low calcium diet induced cancellous bone loss in the W/W v mice. In contrast, W sh /W sh cancellous bone did not respond to this diet. This c-Kit mutation prevented cancellous bone loss by antagonizing the low calcium diet-induced increase in osteoblast and osteoclast numbers in the W sh /W sh mice. Gene expression profiling showed that calcium deficiency increased Osx, Ocn, Alp, type I collagen, c-Fms, M-CSF, and RANKL/OPG mRNA expression in controls; however, the W sh mutation suppressed these effects. Our findings indicate that although calcium restriction increased bone turnover, leading to osteopenia, the decreased c-Kit expression levels in the W sh /W sh mice prevented the low calcium diet-induced increase in cancellous bone turnover and bone loss but not the cortical bone loss.

Using Natural Stable Calcium Isotopes to Rapidly Assess Changes in Bone Mineral Balance Using a Bed Rest Model to Induce Bone Loss

Science.gov (United States)

Morgan, J. L. L.; Skulan, J. L.; Gordon, G. E.; Smith, Scott M.; Romaniello, S. J.; Anbar, A. D.

2012-01-01

Metabolic bone diseases like osteoporosis result from the disruption of normal bone mineral balance (BMB) resulting in bone loss. During spaceflight astronauts lose substantial bone. Bed rest provides an analog to simulate some of the effects of spaceflight; including bone and calcium loss and provides the opportunity to evaluate new methods to monitor BMB in healthy individuals undergoing environmentally induced-bone loss. Previous research showed that natural variations in the Ca isotope ratio occur because bone formation depletes soft tissue of light Ca isotopes while bone resorption releases that isotopically light Ca back into soft tissue (Skulan et al, 2007). Using a bed rest model, we demonstrate that the Ca isotope ratio of urine shifts in a direction consistent with bone loss after just 7 days of bed rest, long before detectable changes in bone mineral density (BMD) occur. The Ca isotope variations tracks changes observed in urinary N-teleopeptide, a bone resorption biomarker. Bone specific alkaline phosphatase, a bone formation biomarker, is unchanged. The established relationship between Ca isotopes and BMB can be used to quantitatively translate the changes in the Ca isotope ratio to changes in BMD using a simple mathematical model. This model predicts that subjects lost 0.25 0.07% ( SD) of their bone mass from day 7 to day 30 of bed rest. Given the rapid signal observed using Ca isotope measurements and the potential to quantitatively assess bone loss; this technique is well suited to study the short-term dynamics of bone metabolism.

Correlation of interdental and interradicular bone loss in patients ...

African Journals Online (AJOL)

2012-01-19

Jan 19, 2012 ... loss in patients with chronic periodontitis: A clinical ... Key words: Alveolar bone loss, chronic periodontitis, dental, furcation defect, ..... cases for regeneration. ... According to report given by AAP[29] on the clinical reality.

An improved cost-effective, reproducible method for evaluation of bone loss in a rodent model.

Science.gov (United States)

Fine, Daniel H; Schreiner, Helen; Nasri-Heir, Cibele; Greenberg, Barbara; Jiang, Shuying; Markowitz, Kenneth; Furgang, David

2009-02-01

This study was designed to investigate the utility of two "new" definitions for assessment of bone loss in a rodent model of periodontitis. Eighteen rats were divided into three groups. Group 1 was infected by Aggregatibacter actinomycetemcomitans (Aa), group 2 was infected with an Aa leukotoxin knock-out, and group 3 received no Aa (controls). Microbial sampling and antibody titres were determined. Initially, two examiners measured the distance from the cemento-enamel-junction to alveolar bone crest using the three following methods; (1) total area of bone loss by radiograph, (2) linear bone loss by radiograph, (3) a direct visual measurement (DVM) of horizontal bone loss. Two "new" definitions were adopted; (1) any site in infected animals showing bone loss >2 standard deviations above the mean seen at that site in control animals was recorded as bone loss, (2) any animal with two or more sites in any quadrant affected by bone loss was considered as diseased. Using the "new" definitions both evaluators independently found that infected animals had significantly more disease than controls (DVM system; p<0.05). The DVM method provides a simple, cost effective, and reproducible method for studying periodontal disease in rodents.

Green tea polyphenols mitigate bone loss of female rats in a chronic inflammation-induced bone loss model

Science.gov (United States)

The purpose of this study was to explore bioavailability, efficacy, and molecular mechanisms of green tea polyphenols (GTP) related to preventing bone loss in rats with chronic inflammation. A 2 (placebo vs. lipopolysaccharide, LPS) × 2 (no GTP vs. 0.5% GTP in drinking water) factorial design using ...

Pattern of alveolar bone loss and reliability of measurements with the radiographic technique

International Nuclear Information System (INIS)

Rise, J.; Albandar, J.M.

1988-01-01

The purposes of this paper were to study the pattern of bone loss among different teeth at the individual level and to study the effect of using different aggregated units of analysis on measurement error. Bone loss was assessed in standardized periapical radiographs from 293 subjects (18-68 years), and the mean bone loss score for each tooth type was calculated. These were then correlated by means of factor analysis to study the bone loss pattern. Reliability (measurement error) was studied by the internal consistency and the test-retest methods. The pattern of bone loss showed a unidimensional pattern, indicating that any tooth will work equally well as a dependent variable for epidemiologic descriptive purposes. However, a more thorough analysis also showed a multidimensional pattern in terms of four dimensions, which correspond to four tooth groups: incisors, upper premolars, lower premolars and molars. The four dimensions accounted for 80% of the toal variance. The multidimensional pattern may be important for the modeling of bone loss; thus different models may explain the four dimension (indices) used as dependent variables. The reliability (internal consistency) of the four indices was satisfactory. By the test-retest method, reliability was higher when the more aggregated unit (the individual) was used

Surface and bulk modified high capacity layered oxide cathodes with low irreversible capacity loss

Science.gov (United States)

Manthiram, Arumugam (Inventor); Wu, Yan (Inventor)

2010-01-01

The present invention includes compositions, surface and bulk modifications, and methods of making of (1-x)Li[Li.sub.1/3Mn.sub.2/3]O.sub.2.xLi[Mn.sub.0.5-yNi.sub.0.5-yCo.sub.2- y]O.sub.2 cathode materials having an O3 crystal structure with a x value between 0 and 1 and y value between 0 and 0.5, reducing the irreversible capacity loss in the first cycle by surface modification with oxides and bulk modification with cationic and anionic substitutions, and increasing the reversible capacity to close to the theoretical value of insertion/extraction of one lithium per transition metal ion (250-300 mAh/g).

Generalized irreversible heat-engine experiencing a complex heat-transfer law

International Nuclear Information System (INIS)

Chen Lingen; Li Jun; Sun Fengrui

2008-01-01

The fundamental optimal relation between optimal power-output and efficiency of a generalized irreversible Carnot heat-engine is derived based on a generalized heat-transfer law, including a generalized convective heat-transfer law and a generalized radiative heat-transfer law, q ∝ (ΔT n ) m . The generalized irreversible Carnot-engine model incorporates several internal and external irreversibilities, such as heat resistance, bypass heat-leak, friction, turbulence and other undesirable irreversibility factors. The added irreversibilities, besides heat resistance, are characterized by a constant parameter and a constant coefficient. The effects of heat-transfer laws and various loss terms are analyzed. The results obtained corroborate those in the literature

FINITE TIME THERMODYNAMIC MODELING AND ANALYSIS FOR AN IRREVERSIBLE ATKINSON CYCLE

Directory of Open Access Journals (Sweden)

Yanlin Ge

2010-01-01

Full Text Available Performance of an air-standard Atkinson cycle is analyzed by using finite-time thermodynamics. The irreversible cycle model which is more close to practice is founded. In this model, the non-linear relation between the specific heats of working fluid and its temperature, the friction loss computed according to the mean velocity of the piston, the internal irreversibility described by using the compression and expansion efficiencies, and heat transfer loss are considered. The relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, as well as the optimal relation between power output and the efficiency of the cycle are derived by detailed numerical examples. Moreover, the effects of internal irreversibility, heat transfer loss and friction loss on the cycle performance are analyzed. The results obtained in this paper may provide guidelines for the design of practical internal combustion engines.

Ecological optimization and parametric study of irreversible Stirling and Ericsson heat pumps

International Nuclear Information System (INIS)

Tyagi, S.K.; Kaushik, S.C.; Salohtra, R.

2002-01-01

This communication presents the ecological optimization and parametric study of irreversible Stirling and Ericsson heat pump cycles, in which the external irreversibility is due to finite temperature difference between working fluid and external reservoirs while the internal irreversibilities are due to regenerative heat loss and other entropy generations within the cycle. The ecological function is defined as the heating load minus the irreversibility (power loss) which is ambient temperature times the entropy generation. The ecological function is optimized with respect to working fluid temperatures, and the expressions for various parameters at the optimal operating condition are obtained. The effects of different operating parameters on the performance of these cycles have been studied. It is found that the effect of internal irreversibility parameter is more pronounced than the other parameters on the performance of these cycles. (author)

Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching.

Science.gov (United States)

Spinato, Sergio; Galindo-Moreno, Pablo; Bernardello, Fabio; Zaffe, Davide

This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas. Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platform-switched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading. The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas. The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss.

Reverse total shoulder glenoid baseplate stability with superior glenoid bone loss.

Science.gov (United States)

Martin, Elise J; Duquin, Thomas R; Ehrensberger, Mark T

2017-10-01

Superior wear of the glenoid bone is common in patients with rotator cuff arthropathy. This can become a treatment challenge for patients who require shoulder arthroplasty. In reverse shoulder arthroplasty (RSA), glenoid bone loss may affect the stability of baseplate fixation. The primary purpose of this biomechanical laboratory study was to assess the initial fixation stability of RSA glenosphere baseplates in the presence of variable amounts of superior glenoid bone loss. High-density solid rigid polyurethane foam (30 pounds/cubic foot) was machined to model the glenoid with variable superior defects that provided different levels of support (100%, 90%, 75%, and 50%) for the glenosphere baseplate. The samples were cyclically loaded (0-750 N at 1 Hz for 5000 cycles) at a 60° glenohumeral angle. The micromotion and migration of the baseplate were calculated from displacement data captured during the loading tests with an array of 3 linear variable differential transformers mounted around the baseplate. Micromotion was significantly greater in samples with 50% defects compared with those with smaller defects. Migration was significantly greater after testing for all defect sizes. Initial fixation of RSA glenosphere baseplates was significantly reduced in models with 50% bone loss on the superior edge compared with models with less bone loss in this high-density bone foam model. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Association Between Dietary Fiber Intake and Bone Loss in the Framingham Offspring Study.

Science.gov (United States)

Dai, Zhaoli; Zhang, Yuqing; Lu, Na; Felson, David T; Kiel, Douglas P; Sahni, Shivani

2018-02-01

Dietary fiber may increase calcium absorption, but its role in bone mineralization is unclear. Furthermore, the health effect of dietary fiber may be different between sexes. We examined the association between dietary fiber (total fiber and fiber from cereal, fruits, vegetables, nuts, and legumes) and bone loss at the femoral neck, trochanter, and lumbar spine (L 2 to L 4 ) in older men and women. In the Framingham Offspring Study, at baseline (1996-2001), diet was assessed using the Willett food-frequency questionnaire, and bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Follow-up BMD was measured in 2001-2005 and 2005-2008 among 792 men (mean age 58.1 years; BMI 28.6 kg/m 2 ) and 1065 women (mean age 57.3 years; BMI 27.2 kg/m 2 ). We used sex-specific generalized estimating equations in multivariable regressions to estimate the difference (β) of annualized BMD change in percent (%ΔBMD) at each skeletal site per 5 g/d increase in dietary fiber. We further estimated the adjusted mean for bone loss (annualized %ΔBMD) among participants in each higher quartile (Q2, Q3, or Q4) compared with those in the lowest quartile (Q1) of fiber intake. Higher dietary total fiber (β = 0.06, p = 0.003) and fruit fiber (β = 0.10, p = 0.008) was protective against bone loss at the femoral neck in men but not in women. When examined in quartiles, men in Q2-Q4 of total fiber had significantly less bone loss at the femoral neck versus those in Q1 (all p fiber from vegetables appeared to be protective against spine bone loss in women but not men. There were no associations with cereal fiber or nut and legume fiber and bone loss in men or women. Our findings suggest that higher dietary fiber may modestly reduce bone loss in men at the hip. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Inhibition of bone resorption in vitro and prevention of ovariectomy-induced bone loss in vivo by flurbiprofen nitroxybutylester (HCT1026).

Science.gov (United States)

Armour, K J; van 't Hof, R J; Armour, K E; Torbergsen, A C; Del Soldato, P; Ralston, S H

2001-09-01

Inhibitors of prostaglandin production, such as nonsteroidal antiinflammatory drugs (NSAIDs), and pharmacologic nitric oxide (NO) donors, such as organic nitrates, have been suggested to protect against bone loss in both humans and experimental animals. Recently, a new class of nitrosylated NSAID (known as NO-NSAIDs) has been developed, which combines the properties of a NO donor with those of a cyclooxygenase (COX) inhibitor. This study investigated the effects of one of these compounds, flurbiprofen nitroxybutylester (HCT1026), on bone metabolism in vitro and in vivo. The effects of HCT1026 on osteoclast formation and resorption were determined in vitro using cocultures of primary mouse osteoblasts and osteoclasts. The effect of HCT1026 in vivo was assessed using a mouse model of ovariectomy-induced bone loss. HCT1026 was significantly more efficacious than the parent compound, flurbiprofen, at inhibiting osteoclast formation and bone resorption in vitro, and these effects could not be reproduced by combinations of flurbiprofen with a variety of NO donors. Studies in vivo showed that HCT1026 protected against ovariectomy-induced bone loss by inhibiting osteoclastic bone resorption, whereas flurbiprofen at similar concentrations was ineffective. These data indicate that HCT1026 is a potent inhibitor of bone resorption in vitro and protects against ovariectomy-induced bone loss in vivo by a novel mechanism that appears to be distinct from its NO donor properties and from its inhibitory effects on COX activity. We conclude that HCT1026 may be of clinical value in the prevention and treatment of inflammatory diseases such as rheumatoid arthritis, which are characterized by joint inflammation as well as periarticular and systemic bone loss.

GLP-1 receptor agonist treatment increases bone formation and prevents bone loss in weight-reduced obese women

DEFF Research Database (Denmark)

Iepsen, Eva Pers Winning; Lundgren, Julie Rehné; Hartmann, Bolette

2015-01-01

with or without administration of the GLP-1 RA liraglutide (1.2mg/day) for 52 weeks. In case of weight gain, up to two meals per day could be substituted with a low-calorie diet product in order to maintain the weight loss. MAIN OUTCOME MEASURES: Total, pelvic and arm-leg bone mineral content (BMC) and bone...... markers (CTX-1 and P1NP) were investigated before, after weight loss and after 52 weeks weight maintenance. Primary end points: Change in BMC and bone markers after 52 weeks weight maintenance with or without GLP-1 RA treatment. RESULTS: Total, pelvic and arm-leg BMC decreased during weight maintenance...... in the control group (ptotal and arm-leg BMC loss was 4 times greater in the control group compared to the liraglutide group (estimated difference 27g (95% CI 5-48), p=0.01), although the 12% weight loss was maintained in both groups...

Anti-osteoporotic activity of harpagide by regulation of bone formation in osteoblast cell culture and ovariectomy-induced bone loss mouse models.

Science.gov (United States)

Chung, Hwa-Jin; Kyung Kim, Won; Joo Park, Hyen; Cho, Lan; Kim, Me-Riong; Kim, Min Jeong; Shin, Joon-Shik; Ho Lee, Jin; Ha, In-Hyuk; Kook Lee, Sang

2016-02-17

Harpagide, an iridoid glucoside, is a constituent of the root of Harpagophytum procumbens var. sublobatum (Engl.) Stapf, Devil's claw which has been used in patients with osteoarthritis (OA). In the present study, we investigated the anti-osteoporotic potential of harpagide and its underlying mechanism of action in in vitro cell culture and in vivo bone loss animal models. Harpagide was obtained from the alkalic hydrolysis of harpagoside, a major constituent of H. procumbens var. sublobatum Analysis of biomarkers for bone formation in osteoblastic MC3T3-E1 cells and bone resorption in osteoclast cells derived from mouse bone marrow cells was performed to evaluate the mechanism of action. The protective activity of harpagide against bone loss was also evaluated in ovariectomized (OVX) mouse model. Harpagide improved bone properties by stimulating the process of differentiation and maturation of osteoblast cells and suppressing the process of RANKL-induced differentiation of osteoclast cells. In OVX-induced bone loss mouse model, oral administration of harpagide significantly improved recovery of bone mineral density, trabecular bone volume, and trabecular number in the femur. Harpagide also prevented increase of trabecular separation and structure model index induced by OVX. Harpagide effectively inhibited the serum levels of biochemical markers of bone loss, including alkaline phosphatase, osteocalcin, C-terminal telopeptide, and tartrate-resistant acid phosphatase. Taken together, the present study demonstrates that harpagide has a potential for prevention of bone loss in OVX mice by regulating the stimulation of osteoblast differentiation and the suppression of osteoclast formation. Therefore, these findings suggest that harpagide might serve as a bioactive compound derived from H. procumbens var. sublobatum for improvement of age-dependent bone destruction disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

CD38 is associated with premenopausal and postmenopausal bone mineral density and postmenopausal bone loss.

LENUS (Irish Health Repository)

Drummond, Frances J

2012-02-03

One goal of osteoporosis research is to identify the genes and environmental factors that contribute to low bone mineral density (BMD) and fracture. Linkage analyses have identified quantitative trait loci (QTLs), however, the genes contributing to low BMD are largely unknown. We examined the potential association of an intronic polymorphism in CD38 with BMD and postmenopausal bone loss. CD38 resides in 4p15, where a QTL for BMD has been described. CD38-\\/- mice display an osteoporotic phenotype at 3 months, with normalization of BMD by 5 months. The CD38 polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 457 postmenopausal and 173 premenopausal Caucasian women whose spine and hip BMD was measured by dual energy X-ray absorptiometry (DXA). Influence of the CD38 polymorphism on bone loss was analyzed in 273 postmenopausal women over a follow-up of 2.94 +\\/- 1.50 years. The CD38-PvuII polymorphism was significantly associated with premenopausal and postmenopausal (P = 0.001) lumbar spine BMD. Women homozygous for the G allele had >14% lower spinal BMD than women with GC\\/CC genotypes. An allele dose effect was observed at the spine in premenopausal (P = 0.002) and postmenopausal (P < 0.001) cohorts. The CD38-PvuII polymorphism was significantly associated with femoral neck BMD in pre- and postmenopausal women (P = 0.002 and P = 0.011, respectively). However, significance was lost following adjustment of hip BMD for covariates in the postmenopausal cohort (P = 0.081). The CD38-PvuII polymorphism was weakly associated with bone loss at the spine (P = 0.024), in postmenopausal women not taking hormone replacement therapy. We suggest that the CD38-PvuII polymorphism may influence the attainment and maintenance of peak BMD and postmenopausal bone loss.

Monoaxial distraction of ulna to second metacarpal followed by single bone forearm in massive post infective radial bone loss

Directory of Open Access Journals (Sweden)

Jitendra N Pal

2012-01-01

Full Text Available Introduction: Radial bone loss associated with gross manus valgus deformity can be managed by open reduction internal fixation using intervening strut bone graft, callus distraction using ring or monoaxial fixator, and achieving union by distraction histogenesis. These methods are particularly suitable when bone loss is small. Single or staged procedure is described for congenital as well as in acquired extensive bone loss of radius. Distraction through radial proximal to distal segments, to achieve reduction of distal radio-ulnar joint (DRUJ, is also described in acquired cases. In the present series, functional results of distraction through ulna to 2 nd metacarpal is studied alongwith, functional status of hand, stability of wrist, level of patient′s satisfaction are also studied. Materials and Methods: 7 unilateral cases of radial loss (M = 5, F = 2 affecting 4 right hands of mean age 17 years (range 9 to 24 years were included in this study. They were treated by distracting through ulna to 2 nd metacarpal to achieve DRUJ alignment in first stage. Subsequently ulna was osteotomised and translated to distal stump of radius. It was then fixed to the distal radial remnant in 30° pronation in dominant and 30° supination non dominant hands. Results: Union was achieved in all cases associated with beneficial cross union of distal ulna. Hand functions improved near to normal, with fully corrected stable wrist joint, hypertrophied ulna and without recurrence. All of them had practically complete loss of forearm rotations, however patients were fully satisfied. Conclusion: This method is particularly suitable when associated with 6 cm or more radial bone loss. But when loss is small, sacrifice of one bone may not be justifiable.

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

2000-01-01

The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

1999-01-01

The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

National Research Council Canada - National Science Library

Wactawski-Wende, Jean

2001-01-01

The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

Vitamin K supplementation does not prevent bone loss in ovariectomized Norway rats

Science.gov (United States)

Despite plausible biological mechanisms, the differential abilities of phylloquinone (PK) and menaquinones (MKn) to prevent bone loss remain controversial. The objective of the current study was to compare the effects of PK, menaquinone-4 (MK-4) and menaquinone-7(MK-7) on the rate of bone loss in o...

The Use of Structural Allograft in Primary and Revision Knee Arthroplasty with Bone Loss

Directory of Open Access Journals (Sweden)

Raul A. Kuchinad

2011-01-01

Full Text Available Bone loss around the knee in the setting of total knee arthroplasty remains a difficult and challenging problem for orthopaedic surgeons. There are a number of options for dealing with smaller and contained bone loss; however, massive segmental bone loss has fewer options. Small, contained defects can be treated with cement, morselized autograft/allograft or metal augments. Segmental bone loss cannot be dealt with through simple addition of cement, morselized autograft/allograft, or metal augments. For younger or higher demand patients, the use of allograft is a good option as it provides a durable construct with high rates of union while restoring bone stock for future revisions. Older patients, or those who are low demand, may be better candidates for a tumour prosthesis, which provides immediate ability to weight bear and mobilize.

Severity and pattern of bone mineral loss in endocrine causes of osteoporosis as compared to age-related bone mineral loss

Directory of Open Access Journals (Sweden)

D Dutta

2016-01-01

Full Text Available Background: Data are scant on bone health in endocrinopathies from India. This study evaluated bone mineral density (BMD loss in endocrinopathies [Graves′ disease (GD, type 1 diabetes mellitus (T1DM, hypogonadotrophic hypogonadism (HypoH, hypergonadotropic hypogonadism (HyperH, hypopituitarism, primary hyperparathyroidism (PHPT] as compared to age-related BMD loss [postmenopausal osteoporosis (PMO, andropause]. Materials and Methods: Retrospective audit of records of patients >30 years age attending a bone clinic from August 2014 to January 2016 was done. Results: Five-hundred and seven records were screened, out of which 420 (females:male = 294:126 were analyzed. A significantly higher occurrence of vitamin D deficiency and insufficiency was noted in T1DM (89.09%, HyperH (85%, and HypoH (79.59% compared to age-related BMD loss (60.02%; P < 0.001. The occurrence of osteoporosis among females and males was 55.41% and 53.97%, respectively, and of osteopenia among females and males was 28.91% and 32.54%, respectively. In females, osteoporosis was significantly higher in T1DM (92%, HyperH (85%, and HypoH (59.26% compared to PMO (49.34%; P < 0.001. Z score at LS, TF, NOF, and greater trochanter (GT was consistently lowest in T1DM women. Among men, osteoporosis was significantly higher in T1DM (76.67% and HypoH (54.55% compared to andropause (45.45%; P = 0.001. Z score at LS, TF, NOF, GT, and TR was consistently lowest in T1DM men. In GD, the burden of osteoporosis was similar to PMO and andropause. BMD difference among the study groups was not significantly different after adjusting for body mass index (BMI and vitamin D. Conclusion: Low bone mass is extremely common in endocrinopathies, warranting routine screening and intervention. Concomitant vitamin D deficiency compounds the problem. Calcium and vitamin D supplementations may improve bone health in this setting.

Buccal bone loss after immediate implantation can be reduced by the flapless approach

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ARTHUR BELÉM NOVAES JR

2011-10-01

Full Text Available Aim: The aim of this study was to evaluate the buccal bone remodeling after immediate implantation with flap or flapless approach. Material and Methods: The mandibular bilateral premolars of 3 dogs were extracted and immediately three implants were placed in both hemi-arches of each dog. Randomly, one hemi-arch was treated with the flapless approach, while in the contra lateral hemi-arch tooth extractions and implant placement were done after mucoperiosteal flap elevation. Non-submerged healing of 12 weeks was provided for both groups. Histomorphometric analysis was done to compare buccal and lingual bone height loss, bone density and bone-to-implant contact in the groups. Fluorescence analysis was performed to investigate the dynamic of bone remodeling in the different groups. Results: There was a significant association between the surgical flap and the extent of bone resorption around immediate implants. The loss of buccal bone height was significantly lower in the flapless group when compared to the flap group (0.98 mm x 2.14 mm, respectively, p<0.05. The coronal and apical buccal bone densities of the flap group were significantly higher when compared to the lingual components, showing anatomical differences between the bone plates. Fluorescence analysis showed no major differences in bone healing between the flap and flapless groups, supporting that the higher loss of buccal bone height is linked to the anatomic characteristics of this plate and to the negative influence of the detachment of the periosteum in immediate implant therapy. Conclusion: The flapless approach for immediate post-extraction implants reduces the buccal bone height loss.

Bonebridge Implantation for Conductive Hearing Loss in a Patient with Oval Window Atresia.

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Kim, Minbum

2015-08-01

The occurrence of oval window atresia is a rare anomaly with conductive hearing loss. Traditional atresia surgeries involve challenging surgical techniques with risks of irreversible inner ear damage. Recent reports on Bonebridge (Medel, Innsbruck, Austria), a novel implantable bone conduction hearing aid system, assert that the device is safe and effective for conductive hearing loss. We present a case of Bonebridge implantation in an eight-year-old girl with bilateral oval window atresia.

The Ovariectomized Rat as a Model for Studying Alveolar Bone Loss in Postmenopausal Women

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Bryan D. Johnston

2015-01-01

Full Text Available In postmenopausal women, reduced bone mineral density at the hip and spine is associated with an increased risk of tooth loss, possibly due to a loss of alveolar bone. In turn, having fewer natural teeth may lead to compromised food choices resulting in a poor diet that can contribute to chronic disease risk. The tight link between alveolar bone preservation, tooth retention, better nutritional status, and reduced risk of developing a chronic disease begins with the mitigation of postmenopausal bone loss. The ovariectomized rat, a widely used preclinical model for studying postmenopausal bone loss that mimics deterioration of bone tissue in the hip and spine, can also be used to study mineral and structural changes in alveolar bone to develop drug and/or dietary strategies aimed at tooth retention. This review discusses key findings from studies investigating mandible health and alveolar bone in the ovariectomized rat model. Considerations to maximize the benefits of this model are also included. These include the measurement techniques used, the age at ovariectomy, the duration that a rat is studied after ovariectomy and habitual diet consumed.

Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice.

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Anderson, Matthew J; Diko, Sindi; Baehr, Leslie M; Baar, Keith; Bodine, Sue C; Christiansen, Blaine A

2016-10-01

Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30-44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within 1 week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss; however, it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study, we investigated the contribution of mechanical unloading to trabecular bone changes observed following non-invasive knee injury in mice (female C57BL/6N). We investigated changes in gait during treadmill walking, and changes in voluntary activity level using Open Field analysis at 4, 14, 28, and 42 days post-injury. We also quantified epiphyseal trabecular bone using μCT and weighed lower-limb muscles to quantify atrophy following knee injury in both ground control and hindlimb unloaded (HLU) mice. Gait analysis revealed a slightly altered stride pattern in the injured limb, with a decreased stance phase and increased swing phase. However, Open Field analysis revealed no differences in voluntary movement between injured and sham mice at any time point. Both knee injury and HLU resulted in comparable magnitudes of trabecular bone loss; however, HLU resulted in considerably more muscle loss than knee injury, suggesting another mechanism contributing to bone loss following injury. Altogether, these data suggest that mechanical unloading likely contributes to trabecular bone loss following non-invasive knee injury, but the magnitude of this bone loss cannot be fully explained by disuse. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1680-1687, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Glycemic control and alveolar bone loss progression in type 2 diabetes.

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Taylor, G W; Burt, B A; Becker, M P; Genco, R J; Shlossman, M

1998-07-01

This study tested the hypothesis that the risk for alveolar bone loss is greater, and bone loss progression more severe, for subjects with poorly controlled (PC) type 2 diabetes mellitus (type 2 DM) compared to those without type 2 DM or with better controlled (BC) type 2 DM. The PC group had glycosylated hemoglobin (HbA1) > or = 9%; the BC group had HbA1 or = 75% were used to identify the worst bone score (WBS) in the dentition. Change in worst bone score at follow-up, the outcome, was specified on a 4-category ordinal scale as no change, or a 1-, 2-, 3-, or 4-category increase over baseline WBS (WBS1). Poorly controlled diabetes, age, calculus, time to follow-up examination, and WBS1 were statistically significant explanatory variables in ordinal logistic regression models. Poorly controlled type 2 DM was positively associated with greater risk for a change in bone score (compared to subjects without type 2 DM) when the covariates were included in the model. The cumulative odds ratio (COR) at each threshold of the ordered response was 11.4 (95% CI = 2.5, 53.3). When contrasted with subjects with BC type 2 DM, the COR for those in the PC group was 5.3 (95% CI = 0.8, 53.3). The COR for subjects with BC type 2 DM was 2.2 (95% CI = 0.7, 6.5), when contrasted to those without type 2 DM. These results suggest that poorer glycemic control leads to both an increased risk for alveolar bone loss and more severe progression over those without type 2 DM, and that there may be a gradient, with the risk for bone loss progression for those with better controlled type 2 DM intermediate to the other 2 groups.

Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice

OpenAIRE

Anderson, Matthew J.; Diko, Sindi; Baehr, Leslie M.; Baar, Keith; Bodine, Sue C.; Christiansen, Blaine A.

2016-01-01

Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30–44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within one week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss, however it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study,...

Identification of a constitutive law for trabecular bone samples under remodeling in the framework of irreversible thermodynamics

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Louna, Zineeddine; Goda, Ibrahim; Ganghoffer, Jean-François

2018-01-01

We construct in the present paper constitutive models for bone remodeling based on micromechanical analyses at the scale of a representative unit cell (RUC) including a porous trabecular microstructure. The time evolution of the microstructure is simulated as a surface remodeling process by relating the surface growth remodeling velocity to a surface driving force incorporating a (surface) Eshelby tensor. Adopting the framework of irreversible thermodynamics, a 2D constitutive model based on the setting up of the free energy density and a dissipation potential is identified from FE simulations performed over a unit cell representative of the trabecular architecture obtained from real bone microstructures. The static and evolutive effective properties of bone at the scale of the RUC are obtained by combining a methodology for the evaluation of the average kinematic and static variables over a prototype unit cell and numerical simulations with controlled imposed first gradient rates. The formulated effective growth constitutive law at the scale of the homogenized set of trabeculae within the RUC is of viscoplastic type and relates the average growth strain rate to the homogenized stress tensor. The postulated model includes a power law function of an effective stress chosen to depend on the first and second stress invariants. The model coefficients are calibrated from a set of virtual testing performed over the RUC subjected to a sequence of loadings. Numerical simulations show that overall bone growth does not show any growth kinematic hardening. The obtained results quantify the strength and importance of different types of external loads (uniaxial tension, simple shear, and biaxial loading) on the overall remodeling process and the development of elastic deformations within the RUC.

Regenerate augmentation with bone marrow concentrate after traumatic bone loss

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Jan Gessmann

2012-03-01

Full Text Available Distraction osteogenesis after post-traumatic segmental bone loss of the tibia is a complex and time-consuming procedure that is often complicated due to prolonged consolidation or complete insufficiency of the regenerate. The aim of this feasibility study was to investigate the potential of bone marrow aspiration concentrate (BMAC for percutaneous regenerate augmentation to accelerate bony consolidation of the regenerate. Eight patients (age 22-64 with an average posttraumatic bone defect of 82.4 mm and concomitant risk factors (nicotine abuse, soft-tissue defects, obesity and/or circulatory disorders were treated with a modified Ilizarov external frame using an intramedullary cable transportation system. At the end of the distraction phase, each patient was treated with a percutaneously injection of autologous BMAC into the centre of the regenerate. The concentration factor was analysed using flow cytometry. The mean follow up after frame removal was 10 (4-15 months. With a mean healing index (HI of 36.9 d/cm, bony consolidation of the regenerate was achieved in all eight cases. The mean concentration factor of the bone marrow aspirate was 4.6 (SD 1.23. No further operations concerning the regenerate were needed and no adverse effects were observed with the BMAC procedure. This procedure can be used for augmentation of the regenerate in cases of segmental bone transport. Further studies with a larger number of patients and control groups are needed to evaluate a possible higher success rate and accelerating effects on regenerate healing.

Cancer treatment-induced bone loss in premenopausal women: a need for therapeutic intervention?

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Hadji, P; Gnant, M; Body, J J; Bundred, N J; Brufsky, A; Coleman, R E; Guise, T A; Lipton, A; Aapro, M S

2012-10-01

Current clinical treatment guidelines recommend cytotoxic chemotherapy, endocrine therapy, or both (with targeted therapy if indicated) for premenopausal women with early-stage breast cancer, depending on the biologic characteristics of the primary tumor. Some of these therapies can induce premature menopause or are specifically designed to suppress ovarian function and reduce circulating estrogen levels. In addition to bone loss associated with low estrogen levels, cytotoxic chemotherapy may have a direct negative effect on bone metabolism. As a result, cancer treatment-induced bone loss poses a significant threat to bone health in premenopausal women with breast cancer. Clinical trials of antiresorptive therapies, such as bisphosphonates, have demonstrated the ability to slow or prevent bone loss in this setting. Current fracture risk assessment tools are based on data from healthy postmenopausal women and do not adequately address the risks associated with breast cancer therapy, especially in younger premenopausal women. We therefore recommend that all premenopausal women with breast cancer be informed about the potential risk of bone loss prior to beginning anticancer therapy. Women who experience amenorrhea should have bone mineral density assessed by dual-energy X-ray absorptiometry and receive regular follow-up to monitor bone health. Regular exercise and daily calcium and vitamin D supplementation are recommended. Women with a Z-score <-2.0 or Z-score ≤-1.0 and/or a 5-10% annual decrease in bone mineral density should be considered for bisphosphonate therapy in addition to calcium and vitamin D supplements. Copyright © 2012 Elsevier Ltd. All rights reserved.

A soluble activin type IIA receptor mitigates the loss of femoral neck bone strength and cancellous bone mass in a mouse model of disuse osteopenia.

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Lodberg, Andreas; Eijken, Marco; van der Eerden, Bram C J; Okkels, Mette Wendelboe; Thomsen, Jesper Skovhus; Brüel, Annemarie

2018-05-01

Disuse causes a rapid and substantial bone loss distinct in its pathophysiology from the bone loss associated with cancers, age, and menopause. While inhibitors of the activin-receptor signaling pathway (IASPs) have been shown to prevent ovariectomy- and cancer-induced bone loss, their application in a model of disuse osteopenia remains to be tested. Here, we show that a soluble activin type IIA receptor (ActRIIA-mFc) increases diaphyseal bone strength and cancellous bone mass, and mitigates the loss of femoral neck bone strength in the Botulinum Toxin A (BTX)-model of disuse osteopenia in female C57BL/6J mice. We show that ActRIIA-mFc treatment preferentially stimulates a dual-effect (anabolic-antiresorptive) on the periosteal envelope of diaphyseal bone, demonstrating in detail the effects of ActRIIA-mFc on cortical bone. These observations constitute a previously undescribed feature of IASPs that mediates at least part of their ability to mitigate detrimental effects of unloading on bone tissue. The study findings support the application of IASPs as a strategy to combat bone loss during disuse. Copyright © 2018 Elsevier Inc. All rights reserved.

Dietary phosphorus exacerbates bone loss induced by cadmium in ovariectomized rats.

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Bakhshalian, Neema; Johnson, Sarah A; Hooshmand, Shirin; Feresin, Rafaela G; Elam, Marcus L; Soung, Do Y; Payton, Mark E; Arjmandi, Bahram H

2014-12-01

Postmenopausal bone loss can be exacerbated by environmental contaminants, including the heavy metal cadmium (Cd). We hypothesized that incorporating phosphorus (P) into the diet would lead to the chelation of Cd into P, preventing its absorption and subsequent bone loss. To test this hypothesis, we used ovariectomized rats as a model of postmenopausal osteoporosis to examine the deleterious effects of Cd on bone with and without added P. Fifty 3-month-old ovariectomized Sprague-Dawley rats were assigned to five treatment groups (n = 10 per group) for 3 months as follows: (1) control; (2) 50 ppm Cd; (3) 50 ppm Cd plus 1.2% P; (4) 200 ppm Cd; and (5) 200 ppm Cd plus 1.2% P. Cd plus P caused a significant loss of whole body (P = 0.0001 and P properties, 50 ppm Cd plus 1.2% P caused an increase in trabecular separation, whereas 200 ppm Cd plus 1.2% P caused a decrease in bone volume-to-total volume ratio, a decrease in trabecular number, and an increase in trabecular separation and structural model index. Our findings indicate that Cd exposure, along with high intake of P, may be a public health hazard with respect to bone health.

Early Subchondral Bone Loss at Arthritis Onset Predicted Late Arthritis Severity in a Rat Arthritis Model.

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Courbon, Guillaume; Cleret, Damien; Linossier, Marie-Thérèse; Vico, Laurence; Marotte, Hubert

2017-06-01

Synovitis is usually observed before loss of articular function in rheumatoid arthritis (RA). In addition to the synovium and according to the "Inside-Outside" theory, bone compartment is also involved in RA pathogenesis. Then, we investigated time dependent articular bone loss and prediction of early bone loss to late arthritis severity on the rat adjuvant-induced arthritis (AIA) model. Lewis female rats were longitudinally monitored from arthritis induction (day 0), with early (day 10) and late (day 17) steps. Trabecular and cortical microarchitecture parameters of four ankle bones were assessed by microcomputed tomography. Gene expression was determined at sacrifice. Arthritis occurred at day 10 in AIA rats. At this time, bone erosions were detected on four ankle bones, with cortical porosity increase (+67%) and trabecular alterations including bone volume fraction (BV/TV: -13%), and trabecular thickness decrease. Navicular bone assessment was the most reproducible and sensitive. Furthermore, strong correlations were observed between bone alterations at day 10 and arthritis severity or bone loss at day 17, including predictability of day 10 BV/TV to day 17 articular index (R 2  = 0.76). Finally, gene expression at day 17 confirmed massive osteoclast activation and interestingly provided insights on strong activation of bone formation inhibitor markers at the joint level. In rat AIA, bone loss was already observed at synovitis onset and was predicted late arthritis severity. Our results reinforced the key role of subchondral bone in arthritis pathogenesis, in favour to the "Inside-Outside" theory. Mechanisms of bone loss in rat AIA involved resorption activation and formation inhibition changes. J. Cell. Physiol. 232: 1318-1325, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The current state of bone loss research: data from spaceflight and microgravity simulators.

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Nagaraja, Mamta Patel; Risin, Diana

2013-05-01

Bone loss is a well documented phenomenon occurring in humans both in short- and in long-term spaceflights. This phenomenon can be also reproduced on the ground in human and animals and also modeled in cell-based analogs. Since space flights are infrequent and expensive to study the biomedical effects of microgravity on the human body, much of the known pathology of bone loss comes from experimental studies. The most commonly used in vitro simulators of microgravity are clinostats while in vivo simulators include the bed rest studies in humans and hindlimb unloading experiments in animals. Despite the numerous reports that have documented bone loss in wide ranges in multiple crew members, the pathology remains a key concern and development of effective countermeasures is still a major task. Thus far, the offered modalities have not shown much success in preventing or alleviating bone loss in astronauts and cosmonauts. The objective of this review is to capture the most recent research on bone loss from spaceflights, bed rest and hindlimb unloading, and in vitro studies utilizing cellular models in clinostats. Additionally, this review offers projections on where the research has to focus to ensure the most rapid development of effective countermeasures. Copyright © 2012 Wiley Periodicals, Inc.

Spaceflight-induced vertebral bone loss in ovariectomized rats is associated with increased bone marrow adiposity and no change in bone formation

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Keune, Jessica A; Philbrick, Kenneth A; Branscum, Adam J; Iwaniec, Urszula T; Turner, Russell T

2016-01-01

There is often a reciprocal relationship between bone marrow adipocytes and osteoblasts, suggesting that marrow adipose tissue (MAT) antagonizes osteoblast differentiation. MAT is increased in rodents during spaceflight but a causal relationship between MAT and bone loss remains unclear. In the present study, we evaluated the effects of a 14-day spaceflight on bone mass, bone resorption, bone formation, and MAT in lumbar vertebrae of ovariectomized (OVX) rats. Twelve-week-old OVX Fischer 344 rats were randomly assigned to a ground control or flight group. Following flight, histological sections of the second lumbar vertebrae (n=11/group) were stained using a technique that allowed simultaneous quantification of cells and preflight fluorochrome label. Compared with ground controls, rats flown in space had 32% lower cancellous bone area and 306% higher MAT. The increased adiposity was due to an increase in adipocyte number (224%) and size (26%). Mineral apposition rate and osteoblast turnover were unchanged during spaceflight. In contrast, resorption of a preflight fluorochrome and osteoclast-lined bone perimeter were increased (16% and 229%, respectively). The present findings indicate that cancellous bone loss in rat lumbar vertebrae during spaceflight is accompanied by increased bone resorption and MAT but no change in bone formation. These findings do not support the hypothesis that increased MAT during spaceflight reduces osteoblast activity or lifespan. However, in the context of ovarian hormone deficiency, bone formation during spaceflight was insufficient to balance increased resorption, indicating defective coupling. The results are therefore consistent with the hypothesis that during spaceflight mesenchymal stem cells are diverted to adipocytes at the expense of forming osteoblasts. PMID:28725730

Progressive irreversible hearing loss is caused by stria vascularis degeneration in an Slc26a4-insufficient mouse model of large vestibular aqueduct syndrome.

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Ito, T; Nishio, A; Wangemann, P; Griffith, A J

2015-12-03

Hearing loss of patients with enlargement of the vestibular aqueduct (EVA) can fluctuate or progress, with overall downward progression. The most common detectable cause of EVA is mutations of SLC26A4. We previously described a transgenic Slc26a4-insufficient mouse model of EVA in which Slc26a4 expression is controlled by doxycycline administration. Mice that received doxycycline from conception until embryonic day 17.5 (DE17.5; doxycycline discontinued at embryonic day 17.5) had fluctuating hearing loss between 1 and 6 months of age with an overall downward progression after 6 months of age. In this study, we characterized the cochlear functional and structural changes underlying irreversible hearing loss in DE17.5 mice at 12 months of age. The endocochlear potential was decreased and inversely correlated with auditory brainstem response thresholds. The stria vascularis was thickened and edematous in ears with less severe hearing loss, and thinned and atrophic in ears with more severe hearing loss. There were pathologic changes in marginal cell morphology and gene expression that were not observed at 3 months. We conclude that strial dysfunction and degeneration are the primary causes of irreversible progressive hearing loss in our Slc26a4-insufficient mouse model of EVA. This model of primary strial atrophy may be used to explore the mechanisms of progressive hearing loss due to strial dysfunction. Published by Elsevier Ltd.

First and Second-Law Efficiency Analysis and ANN Prediction of a Diesel Cycle with Internal Irreversibility, Variable Specific Heats, Heat Loss, and Friction Considerations

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M. M. Rashidi

2014-04-01

Full Text Available The variability of specific heats, internal irreversibility, heat and frictional losses are neglected in air-standard analysis for different internal combustion engine cycles. In this paper, the performance of an air-standard Diesel cycle with considerations of internal irreversibility described by using the compression and expansion efficiencies, variable specific heats, and losses due to heat transfer and friction is investigated by using finite-time thermodynamics. Artificial neural network (ANN is proposed for predicting the thermal efficiency and power output values versus the minimum and the maximum temperatures of the cycle and also the compression ratio. Results show that the first-law efficiency and the output power reach their maximum at a critical compression ratio for specific fixed parameters. The first-law efficiency increases as the heat leakage decreases; however the heat leakage has no direct effect on the output power. The results also show that irreversibilities have depressing effects on the performance of the cycle. Finally, a comparison between the results of the thermodynamic analysis and the ANN prediction shows a maximum difference of 0.181% and 0.194% in estimating the thermal efficiency and the output power. The obtained results in this paper can be useful for evaluating and improving the performance of practical Diesel engines.

Targeting sphingosine-1-phosphate lyase as an anabolic therapy for bone loss.

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Weske, Sarah; Vaidya, Mithila; Reese, Alina; von Wnuck Lipinski, Karin; Keul, Petra; Bayer, Julia K; Fischer, Jens W; Flögel, Ulrich; Nelsen, Jens; Epple, Matthias; Scatena, Marta; Schwedhelm, Edzard; Dörr, Marcus; Völzke, Henry; Moritz, Eileen; Hannemann, Anke; Rauch, Bernhard H; Gräler, Markus H; Heusch, Gerd; Levkau, Bodo

2018-05-01

Sphingosine-1-phosphate (S1P) signaling influences bone metabolism, but its therapeutic potential in bone disorders has remained unexplored. We show that raising S1P levels in adult mice through conditionally deleting or pharmacologically inhibiting S1P lyase, the sole enzyme responsible for irreversibly degrading S1P, markedly increased bone formation, mass and strength and substantially decreased white adipose tissue. S1P signaling through S1P 2 potently stimulated osteoblastogenesis at the expense of adipogenesis by inversely regulating osterix and PPAR-γ, and it simultaneously inhibited osteoclastogenesis by inducing osteoprotegerin through newly discovered p38-GSK3β-β-catenin and WNT5A-LRP5 pathways. Accordingly, S1P 2 -deficient mice were osteopenic and obese. In ovariectomy-induced osteopenia, S1P lyase inhibition was as effective as intermittent parathyroid hormone (iPTH) treatment in increasing bone mass and was superior to iPTH in enhancing bone strength. Furthermore, lyase inhibition in mice successfully corrected severe genetic osteoporosis caused by osteoprotegerin deficiency. Human data from 4,091 participants of the SHIP-Trend population-based study revealed a positive association between serum levels of S1P and bone formation markers, but not resorption markers. Furthermore, serum S1P levels were positively associated with serum calcium , negatively with PTH , and curvilinearly with body mass index. Bone stiffness, as determined through quantitative ultrasound, was inversely related to levels of both S1P and the bone formation marker PINP, suggesting that S1P stimulates osteoanabolic activity to counteract decreasing bone quality. S1P-based drugs should be considered as a promising therapeutic avenue for the treatment of osteoporotic diseases.

Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

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McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

2009-12-01

Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

Block selective redaction for minimizing loss during de-identification of burned in text in irreversibly compressed JPEG medical images.

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Clunie, David A; Gebow, Dan

2015-01-01

Deidentification of medical images requires attention to both header information as well as the pixel data itself, in which burned-in text may be present. If the pixel data to be deidentified is stored in a compressed form, traditionally it is decompressed, identifying text is redacted, and if necessary, pixel data are recompressed. Decompression without recompression may result in images of excessive or intractable size. Recompression with an irreversible scheme is undesirable because it may cause additional loss in the diagnostically relevant regions of the images. The irreversible (lossy) JPEG compression scheme works on small blocks of the image independently, hence, redaction can selectively be confined only to those blocks containing identifying text, leaving all other blocks unchanged. An open source implementation of selective redaction and a demonstration of its applicability to multiframe color ultrasound images is described. The process can be applied either to standalone JPEG images or JPEG bit streams encapsulated in other formats, which in the case of medical images, is usually DICOM.

Male Astronauts Have Greater Bone Loss and Risk of Hip Fracture Following Long Duration Spaceflights than Females

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Ellman, Rachel; Sibonga, Jean; Bouxsein, Mary

2010-01-01

This slide presentation reviews bone loss in males and compares it to female bone loss during long duration spaceflight. The study indicates that males suffer greater bone loss than females and have a greater risk of hip fracture. Two possible reason for the greater male bone loss are that the pre-menopausal females have the estrogen protection and the greater strength of men max out the exercise equipment that provide a limited resistance to 135 kg.

Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice.

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Azuma, Kagaku; Furuzawa, Manabu; Fujiwara, Shu; Yamada, Kumiko; Kubo, Kin-ya

2015-01-01

Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.

Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone.

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Henry Todd

Full Text Available Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading. We therefore investigated Wnt16 expression in the context of ageing, mechanical loading and unloading, estrogen deficiency and replacement, and estrogen receptor α (ERα depletion. Quantitative real time PCR showed that Wnt16 mRNA expression was lower in cortical bone and marrow of aged compared to young female mice. Neither increased nor decreased (by disuse mechanical loading altered Wnt16 expression in young female mice, although Wnt16 expression was decreased following ovariectomy. Both 17β-estradiol and the Selective Estrogen Receptor Modulator Tamoxifen increased Wnt16 expression relative to ovariectomy. Wnt16 and ERβ expression were increased in female ERα-/- mice when compared to Wild Type. We also addressed potential effects of gender on Wnt16 expression and while the expression was lower in the cortical bone of aged males as in females, it was higher in male bone marrow of aged mice compared to young. In the kidney, which we used as a non-bone reference tissue, Wnt16 expression was unaffected by age in either males or females. In summary, age, and its associated bone loss, is associated with low levels of Wnt16 expression whereas bone loss associated with disuse has no effect on Wnt16 expression. In the artificially loaded mouse tibia we observed no loading-related up-regulation of Wnt16 expression but provide evidence that its expression is influenced by estrogen receptor signaling. These findings suggest that while Wnt16 is not an

Performance of an irreversible quantum Ericsson cooler at low temperature limit

International Nuclear Information System (INIS)

Wu Feng; Chen Lingen; Wu Shuang; Sun Fengrui

2006-01-01

The purpose of this paper is to investigate the effect of quantum properties of the working medium on the performance of an irreversible quantum Ericsson cooler with spin-1/2. The cooler is studied with the losses of heat resistance, heat leakage and internal irreversibility. The optimal relationship between the dimensionless cooling load R * versus the coefficient of performance ε for the irreversible quantum Ericsson cooler is derived. In particular, the performance characteristics of the cooler at the low temperature limit are discussed

Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws

OpenAIRE

Carlsson, Gunnar E

2014-01-01

PURPOSE To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. MATERIALS AND METHODS Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. RESULTS Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth an...

General thermodynamic performance of irreversible absorption heat pump

International Nuclear Information System (INIS)

Zhao Xiling; Fu Lin; Zhang Shigang

2011-01-01

The absorption heat pump (AHP) was studied with thermodynamics. A four reservoirs model of absorption heat pump was established considering the heat resistance, heat leak and the internal irreversibility. The reasonable working regions, the performance effects of irreversibility, heat leak and the correlation of four components were studied. When studying the effects of internal irreversibility, two internal irreversibility parameters (I he for generator-absorber assembly and I re for evaporator-condenser assembly) were introduced to distinguish the different effects. When studying the heat transfer relations of four components, a universal relationship between the main parameters were deduced. The results which have more realized meaning show that, the reduction of the friction, heat loss, and internal dissipations of the evaporator-condenser assembly are more important than its reduction of generator-absorber assembly, and lessening the heat leak of generator are more important than its reduction of other components to improve the AHP performance.

Measurement of spinal or peripheral bone mass to estimate early postmenopausal bone loss

International Nuclear Information System (INIS)

Riis, B.J.; Christiansen, C.

1988-01-01

This report presents data from 153 healthy, early postmenopausal women who were randomly allocated to two years of treatment with estrogen or placebo. Bone mineral content in the forearms was measured by single-photon absorptiometry, and bone mineral density of the lumbar spine and total-body bone mineral by dual-photon absorptiometry, before and after one and two years of treatment. At the end of the two years, there were highly significant differences of 6 to 7 percent between the estrogen and the placebo groups at all sites measured. The range of the changes of the spine measurement was twice that of the forearm and total-body measurements. It is concluded that measurement of the forearm by single-photon absorptiometry is superior to measurement of the spine by dual-photon absorptiometry both in clinical studies and in the individual patient for detecting estrogen-dependent bone loss and its treatment by estrogen replacement

Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis)

OpenAIRE

McGee, Meghan E.; Maki, Aaron J.; Johnson, Steven E.; Lynne Nelson, O.; Robbins, Charles T.; Donahue, Seth W.

2007-01-01

Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. ...

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults.

Science.gov (United States)

Madeira, Eduardo; Madeira, Miguel; Guedes, Erika Paniago; Mafort, Thiago Thomaz; Moreira, Rodrigo Oliveira; de Mendonça, Laura Maria Carvalho; Lima, Inayá Correa Barbosa; Neto, Leonardo Vieira; de Pinho, Paulo Roberto Alves; Lopes, Agnaldo José; Farias, Maria Lucia Fleiuss

2018-03-21

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolution peripheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect. Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Recurrent anterior glenohumeral instability: the quantification of glenoid bone loss using magnetic resonance imaging

International Nuclear Information System (INIS)

Martins e Souza, Patricia; Brandao, Bruno Lobo; Motta, Geraldo; Monteiro, Martim; Brown, Eduardo; Marchiori, Edson

2014-01-01

To investigate the accuracy of conventional magnetic resonance imaging (MRI) in determining the severity of glenoid bone loss in patients with anterior shoulder dislocation by comparing the results with arthroscopic measurements. Institutional review board approval and written consent from all patients were obtained. Thirty-six consecutive patients (29 men, seven women; mean age, 34.5 [range, 18-55] years) with recurrent anterior shoulder dislocation (≥3 dislocations; mean, 37.9; range, 3-200) and suspected glenoid bone loss underwent shoulder MRI before arthroscopy (mean interval, 28.5 [range, 9-73] days). Assessments of glenoid bone loss by MRI (using the best-fit circle area method) and arthroscopy were compared. Inter- and intrareader reproducibility of MRI-derived measurements was evaluated using arthroscopy as a comparative standard. Glenoid bone loss was evident on MRI and during arthroscopy in all patients. Inter- and intrareader correlations of MRI-derived measurements were excellent (intraclass correlation coefficient = 0.80-0.82; r = 0.81-0.86). The first and second observers' measurements showed strong (r = 0.76) and moderate (r = 0.69) interreader correlation, respectively, with arthroscopic measurements. Conventional MRI can be used to measure glenoid bone loss, particularly when employed by an experienced musculoskeletal radiologist. (orig.)

Recurrent anterior glenohumeral instability: the quantification of glenoid bone loss using magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Martins e Souza, Patricia [Fleury Medicina e Saude and Instituto Nacional de Traumatologia e Ortopedia, Rio de Janeiro, RJ (Brazil); Brandao, Bruno Lobo; Motta, Geraldo; Monteiro, Martim [Instituto Nacional de Traumatologia e Ortopedia, Rio de Janeiro, RJ (Brazil); Brown, Eduardo [Grupo Fleury Medicina Diagnostica, Rio de Janeiro, RJ (Brazil); Marchiori, Edson [Universidade Federal do Rio de Janeiro, Petropolis, RJ (Brazil)

2014-08-15

To investigate the accuracy of conventional magnetic resonance imaging (MRI) in determining the severity of glenoid bone loss in patients with anterior shoulder dislocation by comparing the results with arthroscopic measurements. Institutional review board approval and written consent from all patients were obtained. Thirty-six consecutive patients (29 men, seven women; mean age, 34.5 [range, 18-55] years) with recurrent anterior shoulder dislocation (≥3 dislocations; mean, 37.9; range, 3-200) and suspected glenoid bone loss underwent shoulder MRI before arthroscopy (mean interval, 28.5 [range, 9-73] days). Assessments of glenoid bone loss by MRI (using the best-fit circle area method) and arthroscopy were compared. Inter- and intrareader reproducibility of MRI-derived measurements was evaluated using arthroscopy as a comparative standard. Glenoid bone loss was evident on MRI and during arthroscopy in all patients. Inter- and intrareader correlations of MRI-derived measurements were excellent (intraclass correlation coefficient = 0.80-0.82; r = 0.81-0.86). The first and second observers' measurements showed strong (r = 0.76) and moderate (r = 0.69) interreader correlation, respectively, with arthroscopic measurements. Conventional MRI can be used to measure glenoid bone loss, particularly when employed by an experienced musculoskeletal radiologist. (orig.)

The relationship between blood lead levels and periodontal bone loss in the United States, 1988-1994.

OpenAIRE

Dye, Bruce A; Hirsch, Rosemarie; Brody, Debra J

2002-01-01

An association between bone disease and bone lead has been reported. Studies have suggested that lead stored in bone may adversely affect bone mineral metabolism and blood lead (PbB) levels. However, the relationship between PbB levels and bone loss attributed to periodontal disease has never been reported. In this study we examined the relationship between clinical parameters that characterize bone loss due to periodontal disease and PbB levels in the U.S. population. We used data from the T...

Repression of osteoblast maturation by ERRα accounts for bone loss induced by estrogen deficiency.

Directory of Open Access Journals (Sweden)

Marlène Gallet

Full Text Available ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation, but not early (commitment, negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency.

Repression of osteoblast maturation by ERRα accounts for bone loss induced by estrogen deficiency.

Science.gov (United States)

Gallet, Marlène; Saïdi, Soraya; Haÿ, Eric; Photsavang, Johann; Marty, Caroline; Sailland, Juliette; Carnesecchi, Julie; Tribollet, Violaine; Barenton, Bruno; Forcet, Christelle; Birling, Marie-Christine; Sorg, Tania; Chassande, Olivier; Cohen-Solal, Martine; Vanacker, Jean-Marc

2013-01-01

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation), but not early (commitment), negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency.

Bone Loss in Space: Shuttle/MIR Experience and Bed Rest Countermeasure Program

Science.gov (United States)

Shackelford, L. C.; LeBlanc, A.; Feiveson, A.; Oganov, V.

1999-01-01

Loss of bone mineral during space flight was documented in the 1970's Skylab missions. The USSR space program made similar observations in the 1980's. The Institute of Biomedical Problems in Moscow and NASA JSC in 1989 began to collect pre- and post-flight bone mineral density (BMD) using Hologic QDR 1000 DEXA scanners transferred from JSC to Moscow and Star City. DEXA whole body, hip, and lumbar spine scans were performed prior to and during the first week after return from 4- to 6-month missions (plus one 8-month mission and one 14- month mission) on the Mir space station. These data documented the extent and regional nature of bone loss during long duration space flight. Of the 18 cosmonauts participating in this study between 1990 and 1995, seven flew two missions. BMD scans prior to the second flight compared to the first mission preflight scans indicated that recovery was possibly delayed or incomplete. Because of these findings, NASA and IBMP initiated the study "Bone Mineral Loss and Recovery After Shuttle/Mir Flights" in 1995 to evaluate bone recovery during a 3-year post-flight period. All of the 14 participants thus far evaluated lost bone in at least one region of the spine and lower extremities during flight. Of the 14, only one to date has exhibited full return to baseline BNM values in all regions. The current study will continue until the last participant has reached full bone recovery in all regions, has reached a plateau, or until three years after the flight (2001 for the last mission of the program). Bone mineral density losses in space and difficulty in returning to baseline indicate a need for countermeasure development. In late 1996 NASA JSC and Baylor College of Medicine were approved to conduct two countermeasure studies during 17 weeks of bed rest. In 1997 the studies were begun in the bed rest facility established by NASA, Baylor College of Medicine, and The Methodist Hospital in Houston. To date, three bed rest controls, five resistive

The Role of Mechanical Stimulation in Recovery of Bone Loss-High versus Low Magnitude and Frequency of Force.

Science.gov (United States)

Nagaraja, Mamta Patel; Jo, Hanjoong

2014-04-02

Musculoskeletal pathologies associated with decreased bone mass, including osteoporosis and disuse-induced bone loss, affect millions of Americans annually. Microgravity-induced bone loss presents a similar concern for astronauts during space missions. Many pharmaceutical treatments have slowed osteoporosis, and recent data shows promise for countermeasures for bone loss observed in astronauts. Additionally, high magnitude and low frequency impact such as running has been recognized to increase bone and muscle mass under normal but not microgravity conditions. However, a low magnitude and high frequency (LMHF) mechanical load experienced in activities such as postural control, has also been shown to be anabolic to bone. While several clinical trials have demonstrated that LMHF mechanical loading normalizes bone loss in vivo, the target tissues and cells of the mechanical load and underlying mechanisms mediating the responses are unknown. In this review, we provide an overview of bone adaptation under a variety of loading profiles and the potential for a low magnitude loading as a way to counteract bone loss as experienced by astronauts.

Transplantation of osteoporotic bone marrow stromal cells rejuvenated by the overexpression of SATB2 prevents alveolar bone loss in ovariectomized rats.

Science.gov (United States)

Xu, Rongyao; Fu, Zongyun; Liu, Xue; Xiao, Tao; Zhang, Ping; Du, Yifei; Yuan, Hua; Cheng, Jie; Jiang, Hongbing

2016-11-01

Estrogen-deficient osteoporosis is an aging-related disease with high morbidity that not only significantly increases a woman's risk of fragility fracture but is also associated with tooth and bone loss in the supporting alveolar bone of the jaw. Emerging evidence suggests that the aging of bone marrow stromal cells (BMSCs) contributes to the development of osteoporosis. In this study, we aimed to investigate the role of the special AT-rich sequence-binding protein 2 (SATB2), a stemness and senescence regulator of craniofacial BMSCs, in rat ovariectomy-induced alveolar osteoporosis. We also sought to determine whether transplantation of SATB2-modified BMSCs could ameliorate estrogen deficient alveolar bone loss. Our data revealed that BMSCs from ovariectomy-induced alveolar bone exhibited typical senescence phenotypes such as diminished stemness and osteogenic capacity, increased expression of senescence or osteoclastic markers and enhanced adipogenic potential. These phenotypic changes are a result of SATB2-mediated senescence dysregulation as evidenced by nuclear γH2AX foci formation. Moreover, overexpression of SATB2 significantly alleviated the senescence of osteoporotic BMSCs in vitro. Importantly, transplantation of SATB2-modified BMSCs significantly attenuated ovariectomy-induced alveolar bone loss in vivo. Together, our results revealed that SATB2 is a critical regulator of alveolar BMSC senescence, and its overexpression decreases these senescent changes both in vitro and in vivo. SATB2-modified BMSC delivery could be a viable and promising therapeutic strategy for alveolar bone loss induced by estrogen-deficient osteoporosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Correlation of interdental and interradicular bone loss in patients ...

African Journals Online (AJOL)

2012-01-19

Jan 19, 2012 ... This was followed by Tukeys HSD post hoc tests to know the significant difference ... Key words: Alveolar bone loss, chronic periodontitis, dental, furcation defect, ... The main goals of the diagnosis of periodontal disease.

Bone-anchored hearing devices in children with unilateral conductive hearing loss: a patient-carer perspective.

Science.gov (United States)

Banga, Rupan; Doshi, Jayesh; Child, Anne; Pendleton, Elizabeth; Reid, Andrew; McDermott, Ann-Louise

2013-09-01

We sought to determine the outcome of implantation of a bone-anchored hearing device in children with unilateral conductive hearing loss. A retrospective case note analysis was used in a tertiary referral pediatric hospital to study 17 consecutive cases of pediatric patients with unilateral conductive hearing loss who were fitted with a bone-anchored hearing device between 2005 and 2010. The average age of the patients at the time of bone-anchored hearing device fitting was 10 years 6 months (range, 6 years 3 months to 16 years). Qualitative subjective outcome measures demonstrated benefit. The vast majority of patients reported improved social and physical functioning and improved quality of life. All 17 patients are currently using their bone-anchored hearing device on a daily basis after a follow-up of 6 months. This study has shown improved quality of life in children with unilateral hearing loss after implantation of their bone-anchored hearing device. There was a high degree of patient satisfaction and improvement in health status reported by children and/or carers. Bone-anchored hearing devices have an important role in the management of children with symptomatic unilateral hearing loss. Perhaps earlier consideration of a bone-anchored hearing device would be appropriate in selected cases.

The Role of Peripheral Nerve Function in Age-Related Bone Loss and Changes in Bone Adaptation

Science.gov (United States)

2015-12-01

E Production of Osteoblasts, and Attenuates the Inflammatory Bone Loss Induced by Lipopolysaccharide. ISRN Pharmacol, 2012. 2012: p. 439860. 17...Kobayashi M, Watanabe K, Yokoyama S, et al. Capsaicin, a TRPV1 Ligand, Suppresses Bone Resorption by Inhibit- ing the Prostaglandin E Production of...example, mechanoreceptors in the skin respond to bending and stretching and can provide information about touch. Pacini’s corpuscle consists of onion like

An Unusual Bone Loss Around Implants

Directory of Open Access Journals (Sweden)

Amirreza Rokn

2013-01-01

Full Text Available AbstractPre-implant disease is an inflammatory process, which can affect the surrounding tissues of a functional Osseointegrated implant that is usually as a result of a disequilibrium between the micro-flora and the body defense system.This case reports a 57 years old male with unusual bone loss around dental implants.This was an unusual case of peri-implantitis which occurred only in the implants on one side of the mouth although they all were unloaded implants.

Bisphosphonate effects in rat unloaded hindlimb bone loss model: three-dimensional microcomputed tomographic, histomorphometric, and densitometric analyses.

Science.gov (United States)

Barou, O; Lafage-Proust, M H; Martel, C; Thomas, T; Tirode, F; Laroche, N; Barbier, A; Alexandre, C; Vico, L

1999-10-01

The effects of antiresorptive drugs on bone loss remain unclear. Using three-dimensional microtomography, dual X-ray/densitometry, and histomorphometry, we evaluated tiludronate effects in the bone loss model of immobilization in tail-suspended rats after 7, 13, and 23 days. Seventy-eight 12-week-old Wistar male rats were assigned to 13 groups: 1 baseline group, and for each time point, 1 control group treated with vehicle and three tail-suspended groups treated with either tiludronate (0.5 or 5 mg/kg) or vehicle, administered s. c. every other day, during the last week before sacrifice. In primary spongiosa (ISP), immobilization-induced bone loss plateaued after day 7 and was prevented by tiludronate. In secondary spongiosa (IISP), bone loss appeared at day 13 with a decrease in trabecular thickness and trabecular number (Tb.N) as assessed by three-dimensional microtomography. Osteoclastic parameters did not differ in tail-suspended rats versus control rats, whereas bone formation showed a biphasic pattern: after a marked decrease at day 7, osteoblastic activity and recruitment normalized at days 13 and 23, respectively. At day 23, the 80% decrease in bone mass was fully prevented by high-dose tiludronate with an increase in Tb.N without preventing trabecular thinning. In summary, at day 7, tiludronate prevented bone loss in ISP. After day 13, tiludronate prevented bone loss in ISP and IISP despite a further decrease in bone formation. Thus, the preventive effects of tiludronate in this model may be related to the alteration in bone modeling with an increase in Tb.N in ISP and subsequently in IISP.

Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

Science.gov (United States)

McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

2008-02-01

Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

A statistical method (cross-validation) for bone loss region detection after spaceflight

Science.gov (United States)

Zhao, Qian; Li, Wenjun; Li, Caixia; Chu, Philip W.; Kornak, John; Lang, Thomas F.

2010-01-01

Astronauts experience bone loss after the long spaceflight missions. Identifying specific regions that undergo the greatest losses (e.g. the proximal femur) could reveal information about the processes of bone loss in disuse and disease. Methods for detecting such regions, however, remains an open problem. This paper focuses on statistical methods to detect such regions. We perform statistical parametric mapping to get t-maps of changes in images, and propose a new cross-validation method to select an optimum suprathreshold for forming clusters of pixels. Once these candidate clusters are formed, we use permutation testing of longitudinal labels to derive significant changes. PMID:20632144

Evolutionary medicine and bone loss in chronic inflammatory diseases--A theory of inflammation-related osteopenia.

Science.gov (United States)

Straub, Rainer H; Cutolo, Maurizio; Pacifici, Roberto

2015-10-01

Bone loss is typical in chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel diseases, pemphigus vulgaris, and others. It is also typical in transplantation-related inflammation and during the process of aging. While we recognized that bone loss is tightly linked to immune system activation or inflamm-aging in the form of acute, chronic active, or chronic smoldering inflammation, bone loss is typically discussed to be an "accident of inflammation." Extensive literature search in PubMed central. Using elements of evolutionary medicine, energy regulation, and neuroendocrine regulation of homeostasis and immune function, we work out that bone waste is an adaptive, evolutionarily positively selected program that is absolutely necessary during acute inflammation. However, when acute inflammation enters a chronic state due to the inability to terminate inflammation (e.g., in autoimmunity or in continuous immunity against microbes), the acute program of bone loss is a misguided adaptive program. The article highlights the complexity of interwoven pathways of osteopenia. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Effect of dietary soy isoflavones on bone loss in ovariectomized rats ...

African Journals Online (AJOL)

Purpose: To determine the effect of dietary soy isoflavone supplementation on bone loss in ovariectomized (OVX) rats. Methods: Forty-eight rats were assigned randomly to groups of OVX rats receiving soy isoflavones (20, 30, or 40 mg/kg of body weight daily), untreated OVX rats, or untreated intact rats. After 8 weeks, bone ...

The effects of simulated bone loss on the implant-abutment assembly and likelihood of fracture: an in vitro study.

Science.gov (United States)

Manzoor, Behzad; Suleiman, Mahmood; Palmer, Richard M

2013-01-01

The crestal bone level around a dental implant may influence its strength characteristics by offering protection against mechanical failures. Therefore, the present study investigated the effect of simulated bone loss on modes, loads, and cycles to failure in an in vitro model. Different amounts of bone loss were simulated: 0, 1.5, 3.0, and 4.5 mm from the implant head. Forty narrow-diameter (3.0-mm) implant-abutment assemblies were tested using compressive bending and cyclic fatigue testing. Weibull and accelerated life testing analysis were used to assess reliability and functional life. Statistical analyses were performed using the Fisher-Exact test and the Spearman ranked correlation. Compressive bending tests showed that the level of bone loss influenced the load-bearing capacity of implant-abutment assemblies. Fatigue testing showed that the modes, loads, and cycles to failure had a statistically significant relationship with the level of bone loss. All 16 samples with bone loss of 3.0 mm or more experienced horizontal implant body fractures. In contrast, 14 of 16 samples with 0 and 1.5 mm of bone loss showed abutment and screw fractures. Weibull and accelerated life testing analysis indicated a two-group distribution: the 0- and 1.5-mm bone loss samples had better functional life and reliability than the 3.0- and 4.5-mm samples. Progressive bone loss had a significant effect on modes, loads, and cycles to failure. In addition, bone loss influenced the functional life and reliability of the implant-abutment assemblies. Maintaining crestal bone levels is important in ensuring biomechanical sustainability and predictable long-term function of dental implant assemblies.

Comparison of bone density in amenorrheic women due to athletics, weight loss, and premature menopause.

Science.gov (United States)

Jones, K P; Ravnikar, V A; Tulchinsky, D; Schiff, I

1985-07-01

Studied was the peripheral bone density of 39 women (ages 18 to 43) with the diagnosis of secondary amenorrhea in an effort to define the population of amenorrheic women at risk for osteoporosis. Eight women had exercise-induced amenorrhea (athletes), 20 women had amenorrhea associated with weight loss, and 11 women had premature menopause. These diagnoses were made on the basis of history, physical examination, and luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin levels, and failure to have withdrawal bleeding after the administration of progestin. Twenty-five nonathletic, normally menstruating women served as control subjects. The peripheral bone density of the amenorrheic athletes (0.738 g/cm2 +/- 0.047) was not significantly different from that of the controls (0.726 g/cm2 +/- 0.044). The average bone density of the group with weight loss-associated amenorrhea (0.672 g/cm2 +/- 0.066) was significantly less than controls (P less than .005) as was that of the women with premature menopause (0.616 g/cm2 +/- 0.048, P less than .001). There was a significant correlation between months of amenorrhea and decrease in bone density (r = 0.506, P less than .001). From this study it was concluded that women with exercise-associated amenorrhea are not at significant risk for cortical bone loss as measured by direct photon absorptiometry. Women with weight loss-associated amenorrhea and women with premature menopause are at significant risk for bone loss when compared with normal controls.

Marginal bone loss and dental implant failure may be increased in smokers.

Science.gov (United States)

Veitz-Keenan, Analia

2016-03-01

An electronic search was performed in PubMed, Web of Science and the Cochrane Central Register of Controlled Trials up to February 2015. References of included studies were also searched. No language restrictions were applied. Study selection: Prospective, retrospective and randomised clinical trials that compared marginal bone loss and failure rates between smokers and non-smokers. Implant failure was considered as total loss of the implant. Studies with patients who had periodontal disease prior to treatment or who had metabolic diseases were excluded. Two reviewers were involved in the research and screening process and disagreements were resolved by discussion. The quality of the studies was analysed using the Newcastle-Ottawa scale for non-randomised clinical trials. Data extracted from the studies included, when available: follow up period, number of subjects, smoking status, number of implants placed, implant system, implant length and diameter, healing period, antibiotics and mouth-rinse use, marginal bone loss, failure rate and drop-outs. For binary outcomes (implant failure) the estimate of the intervention effect was expressed in the form of an odds ratio (OR) with the confidence interval (CI) of 95%. For continuous outcomes (marginal bone loss) the average and standard deviation (SD) were used to calculate the standardised mean difference with a 95% CI. Meta-analysis was performed for studies with similar outcomes, I(2) a statistical test was used to express the heterogeneity among the studies. Publication bias was explored as well. A total of 15 observational studies were included in the review. The number of participants ranged from 60 to 1727 and the average age was 52.5 years. The follow-up period ranged from eight to 240 months. The total number of implants placed was 5840 in smokers and 14,683 in non-smokers. The Branemak system, (Noble Biocare AB, Goteborg, Sweden), was the most commonly used implant system. There was a statistically significant

The orally available Btk inhibitor ibrutinib (PCI-32765) protects against osteoclast-mediated bone loss.

Science.gov (United States)

Shinohara, Masahiro; Chang, Betty Y; Buggy, Joseph J; Nagai, Yusuke; Kodama, Tatsuhiko; Asahara, Hiroshi; Takayanagi, Hiroshi

2014-03-01

Bone-resorbing osteoclasts play an essential role in normal bone homeostasis, as well as in various bone disorders such as osteoporosis and rheumatoid arthritis. Previously we showed that the Tec family of tyrosine kinases is essential for the differentiation of osteoclasts and the inhibition of Btk is a promising strategy for the prevention of the bone loss in osteoclast-associated bone disorders. Here we demonstrate that an orally available Btk inhibitor, ibrutinib (PCI-32765), suppresses osteoclastic bone resorption by inhibiting both osteoclast differentiation and function. Ibrutinib downregulated the expression of NFATc1, the key transcription factor for osteoclastogenesis, and disrupted the formation of the actin ring in mature osteoclasts. In addition, genome-wide screening revealed that Btk regulates the expression of the genes involved in osteoclast differentiation and function in both an NFATc1-dependent and -independent manner. Finally, we showed that ibrutinib administration ameliorated the bone loss that developed in a RANKL-induced osteoporosis mouse model. Thus, this study suggests ibrutinib to be a promising therapeutic agent for osteoclast-associated bone diseases. Copyright © 2013 Elsevier Inc. All rights reserved.

Vitamin K’s role in age-related bone loss: A critical review

Science.gov (United States)

The protective role of vitamin K in age-related bone loss continues to be controversial. The results of observational analyses are inconsistent with respect to associations between vitamin K status and bone, which arguably may be related to the limitations of observational study designs and analyt...

Two Different Isomers of Vitamin E Prevent Bone Loss in Postmenopausal Osteoporosis Rat Model

Directory of Open Access Journals (Sweden)

Norliza Muhammad

2012-01-01

Full Text Available Postmenopausal osteoporotic bone loss occurs mainly due to cessation of ovarian function, a condition associated with increased free radicals. Vitamin E, a lipid-soluble vitamin, is a potent antioxidant which can scavenge free radicals in the body. In this study, we investigated the effects of alpha-tocopherol and pure tocotrienol on bone microarchitecture and cellular parameters in ovariectomized rats. Three-month-old female Wistar rats were randomly divided into ovariectomized control, sham-operated, and ovariectomized rats treated with either alpha-tocopherol or tocotrienol. Their femurs were taken at the end of the four-week study period for bone histomorphometric analysis. Ovariectomy causes bone loss in the control group as shown by reduction in both trabecular volume (BV/TV and trabecular number (Tb.N and an increase in trabecular separation (Tb.S. The increase in osteoclast surface (Oc.S and osteoblast surface (Ob.S in ovariectomy indicates an increase in bone turnover rate. Treatment with either alpha-tocopherol or tocotrienol prevents the reduction in BV/TV and Tb.N as well as the increase in Tb.S, while reducing the Oc.S and increasing the Ob.S. In conclusion, the two forms of vitamin E were able to prevent bone loss due to ovariectomy. Both tocotrienol and alpha-tocopherol exert similar effects in preserving bone microarchitecture in estrogen-deficient rat model.

Safflower bud inhibits RANKL-induced osteoclast differentiation and prevents bone loss in ovariectomized mice.

Science.gov (United States)

Choi, Joo-Hee; Lim, Seul-Ki; Kim, Dong-Il; Park, Min-Jung; Kim, Young-Kuk; Lee, An-Chul; Kim, Young-Min; Yang, Soo-Jin; Park, Jong-Hwan

2017-10-15

The powder and extract of safflower seeds are known to be effective in the prevention of bone loss in ovariectomized animals. However, the inhibitory effect and molecular mechanisms of safflower bud (SB), the germinated safflower, on bone destruction is unclear. The present study was designed to investigate the inhibitory effect and molecular mechanism of SB on osteoclastic differentiation and on bone loss in ovarietomized (OVX) mice. Osteoclastogenesis was determined by TRAP staining, F-actin ring formation, and bone resorption assay. NF-κB and MAPKs activation was analyzed by transfection assay and Western blot, respectively. Real-time PCR was performed to examine the expression of osteoclastogenesis-related genes. Histological changes, increases in TRAP-positive cells, and cathepsin K expression were examined in the metaphysis of OVX mice. Density of bone marrow was evaluated by µCT. SB inhibited the RANKL-induced differentiation of BMDMs into osteoclasts in a dose-dependent manner. F-actin ring formation and bone resorption were also reduced by SB in RANKL-treated BMDMs. In addition, SB decreased the activation of NF-κB and MAPKs and the expression of osteoclastogenesis-related genes in BMDMs treated with RANKL. Feeding of SB-included diet prevented bone loss in OVX mice. The number of TRAP-positive cells and level of protein expression of cathepsin K was reduced and bone mineral density was increased in the metaphysis of mice fed SB compared with OVX mice. These findings suggest that SB can be a preventive and therapeutic candidate for destructive bone diseases. Copyright © 2017. Published by Elsevier GmbH.

Correlation of interdental and interradicular bone loss in patients ...

African Journals Online (AJOL)

Objective: The aim of this study was to investigate the correlation between interdental and interradicular bone loss and clinical parameters in patients with chronic periodontitis. Materials and Methods: One hundred-twenty intraoral periapical radiographs of first molars were obtained from patients with chronic periodontitis ...

Alveolar bone loss and mineralization in the pig with experimental periodontal disease

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Mandee Yang

2018-03-01

Full Text Available Objective: To address how experimental periodontal disease affects alveolar bone mass and mineral apposition in a young pig model. Materials and methods: Seven three-month-old pigs were periodically inoculated with 4 types of periodontal bacteria, along with a ligature around the last maxillary deciduous molar for 8 weeks to induce periodontal disease (PG. Eight same-aged pigs served as the control (CG. Segmentations of 3D cone-beam CT images were performed to quantify volumes of the total alveolar bone, alveolar ridge, and all roots of the target molar. Calcein and alizarin were administered for labeling mineral apposition before euthanasia. The harvested molar blocks were sectioned and examined under epifluorescence. The inter-label distance between the two vital markers at regional bone surfaces were measured and mineral apposition rate (MAR was calculated. Results: A significant reduction of total alveolar bone volume was seen in PG with the major loss at the alveolar ridge. MAR was significantly higher at the root furcation region than those at both buccal and palatal ridges in CG. Compared with CG, PG animals showed more interrupted labeled bands with significantly lower MAR at the furcation region. MARs were positively associated with both the volumes of total alveolar bone and ridge in CG, but only with the total alveolar bone in PG. Conclusions: In young growing pigs, mineral apposition is region specific. The experimental periodontal disease not only leads to alveolar bone loss, but also perturbs mineral apposition for new bone formation, thus impairing the homeostasis of alveolar bone remodeling. Keyword: Dentistry

Rate of bone loss in postmenopausal and osteoporotic women

International Nuclear Information System (INIS)

Aloia, J.F.; Ross, P.; Vaswani, A.; Zanzi, I.; Cohn, S.H.

1982-01-01

Regional and total bone mass were determined in three groups of women by photon absorptiometry of the distal radius [bone mineral content (BMC)] and total neutron activation analysis [total body calcium (TBCa)], respectively. There were three groups of patients: group A, osteoporotic women treated with a variety of pharmacologic agents; group B, osteoporotic women (controls) taking only calcium supplements; and group C, normal postmenopausal women. The mean TBCa and BMC were considerably higher in the postmenopausal women than in the osteoporotic women. The rate of change of bone mass in group C was -0.45%/yr and -0.9%/yr for the total skeleton and radius, respectively. Group B had no significant rate of loss, whereas group A demonstrated a significant increase in TBCa of 0.75%/yr with no change in the BMC of the radius. There were no significant between-subject correlations for the slopes (rates of change) of the two bone mineral measurements

Epidemiologic Analyses of Risk Factors for Bone Loss and Recovery Related to Long-Duration Space Flight

Science.gov (United States)

Sibonga, Jean; Amin, Shreyasee

2010-01-01

AIM 1: To investigate the risk of microgravity exposure on long-term changes in bone health and fracture risk. compare data from crew members ("observed") with what would be "expected" from Rochester Bone Health Study. AIM 2: To provide a summary of current evidence available on potential risk factors for bone loss, recovery & fracture following long-duration space flight. integrative review of all data pre, in-, and post-flight across disciplines (cardiovascular, nutrition, muscle, etc.) and their relation to bone loss and recovery

The universal power and efficiency characteristics for irreversible reciprocating heat engine cycles

CERN Document Server

Qin Xiao Yong; Sun Feng Rui; Wu Chih

2003-01-01

The performance of irreversible reciprocating heat engine cycles with heat transfer loss and friction-like term loss is analysed using finite-time thermodynamics. The universal relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, and the optimal relation between power output and the efficiency of the cycles are derived. Moreover, analysis and optimization of the model were carried out in order to investigate the effect of cycle processes on the performance of the cycle using numerical examples. The results obtained herein include the performance characteristics of irreversible reciprocating Diesel, Otto, Atkinson and Brayton cycles.

Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws.

Science.gov (United States)

Carlsson, Gunnar E

2014-08-01

To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results.

Implant and root supported overdentures - a literature review and some data on bone loss in edentulous jaws

Science.gov (United States)

2014-01-01

PURPOSE To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. MATERIALS AND METHODS Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. RESULTS Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. CONCLUSION In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results. PMID:25177466

Systemic Administration of Allogeneic Mesenchymal Stem Cells Does Not Halt Osteoporotic Bone Loss in Ovariectomized Rats.

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Shuo Huang

Full Text Available Mesenchymal stem cells (MSCs have innate ability to self-renew and immunosuppressive functions, and differentiate into various cell types. They have become a promising cell source for treating many diseases, particular for bone regeneration. Osteoporosis is a common metabolic bone disorder with elevated systemic inflammation which in turn triggers enhanced bone loss. We hypothesize that systemic infusion of MSCs may suppress the elevated inflammation in the osteoporotic subjects and slow down bone loss. The current project was to address the following two questions: (1 Will a single dose systemic administration of allogenic MSCs have any effect on osteoporotic bone loss? (2 Will multiple administration of allogenic MSCs from single or multiple donors have similar effect on osteoporotic bone loss? 18 ovariectomized (OVX rats were assigned into 3 groups: the PBS control group, MSCs group 1 (receiving 2x106 GFP-MSCs at Day 10, 46, 91 from the same donor following OVX and MSCs group 2 (receiving 2x106 GFP-MSCs from three different donors at Day 10, 46, 91. Examinations included Micro-CT, serum analysis, mechanical testing, immunofluorescence staining and bone histomorphometry analysis. Results showed that BV/TV at Day 90, 135, BMD of TV and trabecular number at Day 135 in the PBS group were significantly higher than those in the MSCs group 2, whereas trabecular spacing at Day 90, 135 was significantly smaller than that in MSCs group 2. Mechanical testing data didn't show significant difference among the three groups. In addition, the ELISA assay showed that level of Rantes in serum in MSCs group 2 was significantly higher than that of the PBS group, whereas IL-6 and IL-10 were significantly lower than those of the PBS group. Bone histomorphometry analysis showed that Oc.S/BS and Oc.N/BS in the PBS group were significant lower than those in MSCs group 2; Ob.S/BS and Ob.N/BS did not show significant difference among the three groups. The current study

Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice

DEFF Research Database (Denmark)

Ørnbjerg, Lykke Midtbøll; Østergaard, Mikkel; Jensen, Trine

2016-01-01

remission (0.0032 vs. 0.0058 g/cm(2)/year; p clinical practice, and only......BACKGROUND: Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking....... In this study, we aimed to: 1) establish reference values for normal hand bone mass (bone mineral density measured by digital x-ray radiogrammetry (DXR-BMD)); and 2) examine whether HBL is normalised in rheumatoid arthritis patients during treatment with tumour necrosis factor alpha inhibitors (TNFI). METHODS...

Irreversible social change

NARCIS (Netherlands)

Pols, A.J.K.; Romijn, H.A.; Collste, G.; Reuter, L.

2014-01-01

In this paper we evaluate how irreversible social change should be evaluated from an ethical perspective. First; we analyse the notion of irreversibility in general terms. We define a general notion of what makes a change irreversible; drawing on discussions in ecology and economics. This notion is

Fermi-Pasta-Ulam Recurrence in Nonlinear Fiber Optics: The Role of Reversible and Irreversible Losses

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Arnaud Mussot

2014-03-01

Full Text Available The discovery of the Fermi-Pasta-Ulam (FPU recurrence phenomenon in the 1950 s was a major step in science that later led to the discovery of solitons in nonlinear physics. More recently, it was shown that optical fibers can serve as a medium for observing the FPU phenomenon. In the present work, we have found experimentally and numerically that in the low-dispersion region of an optical fiber, the recurrence is strongly influenced by the third-order-dispersion (TOD term. Namely, the presence of TOD leads to several disappearances and recoveries of the FPU recurrence when the central frequency of the pump wave is varied. The effect is highly nontrivial and can be explained in terms of reversible and irreversible losses caused by Cherenkov radiations interacting with a multiplicity of modes sharing the optical energy in the process of its partition.

Effects of obesity and diabetes on rate of bone density loss.

Science.gov (United States)

Leslie, W D; Morin, S N; Majumdar, S R; Lix, L M

2018-01-01

In this large registry-based study, women with diabetes had marginally greater bone mineral density (BMD) loss at the femoral neck but not at other measurement sites, whereas obesity was not associated with greater BMD loss. Our data do not support the hypothesis that rapid BMD loss explains the increased fracture risk associated with type 2 diabetes and obesity observed in prior studies. Type 2 diabetes and obesity are associated with higher bone mineral density (BMD) which may be less protective against fracture than previously assumed. Inconsistent data suggest that rapid BMD loss may be a contributing factor. We examined the rate of BMD loss in women with diabetes and/or obesity in a population-based BMD registry for Manitoba, Canada. We identified 4960 women aged ≥ 40 years undergoing baseline and follow-up BMD assessments (mean interval 4.3 years) without confounding medication use or large weight fluctuation. We calculated annualized rate of BMD change for the lumbar spine, total hip, and femoral neck in relation to diagnosed diabetes and body mass index (BMI) category. Baseline age-adjusted BMD was greater in women with diabetes and for increasing BMI category (all P obese women but BMI did not significantly affect hip BMD loss.

Treatment of Radix Dipsaci extract prevents long bone loss induced by modeled microgravity in hindlimb unloading rats.

Science.gov (United States)

Niu, Yinbo; Li, Chenrui; Pan, Yalei; Li, Yuhua; Kong, Xianghe; Wang, Shuo; Zhai, YuanKun; Wu, Xianglong; Fan, Wutu; Mei, Qibing

2015-01-01

Radix Dipsaci is a kidney tonifying herbal medicine with a long history of safe use for treatment of bone fractures and joint diseases in China. Previous studies have shown that Radix Dipsaci extract (RDE) could prevent bone loss in ovariectomized rats. This study investigates the effect of RDE against bone loss induced by simulated microgravity. A hindlimb unloading rat model was established to determine the effect of RDE on bone mineral density and bone microarchitecture. Twenty-four male Sprague-Dawley rats were divided into four groups (n = 6 per group): control (CON), hindlimb unloading with vehicle (HLU), hindlimb unloading treated with alendronate (HLU-ALN, 2.0 mg/kg/d), and hindlimb unloading treated with RDE (HLU-RDE, 500 mg/kg/d). RDE or ALN was administrated orally for 4 weeks. Treatment with RDE had a positive effect on mechanical strength, BMD, BMC, bone turnover markers, and the changes in urinary calcium and phosphorus excretion. MicroCT analysis showed that RDE significantly prevented the reduction of the bone volume fraction, connectivity density, trabecular number, thickness, tissue mineral density, and tissue mineral content as well as improved the trabecular separation and structure model index. RDE was demonstrated to prevent the loss of bone mass induced by HLU treatment, which suggests the potential application of RDE in the treatment of microgravity-induced bone loss.

Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

Science.gov (United States)

Liu, JunLi; Wang, YiHu; Song, ShuJun; Wang, XiJie; Qin, YaYa; Si, ShaoYan; Guo, YanChuan

2015-01-01

Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone. Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers. OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels. Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

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JunLi Liu

Full Text Available Collagen peptides (CPs and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8 for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg; OVX + calcium citrate (75 mg/kg. After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

Effects of total flavonoids from Drynariae Rhizoma prevent bone loss in vivo and in vitro

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Shuang-hong Song

2016-12-01

Full Text Available Estrogen deficiency is one of the major causes of osteoporosis in postmenopausal women. Drynariae Rhizoma is a widely used traditional Chinese medicine for the treatment of bone diseases. In this study, we investigated the therapeutic effects of the total Drynariae Rhizoma flavonoids (DRTF on estrogen deficiency-induced bone loss using an ovariectomized rat model and osteoblast-like MC3T3-E1 cells. Our results indicated that DRTF produced osteo-protective effects on the ovariectomized rats in terms of bone loss reduction, including decreased levels of bone turnover markers, enhanced biomechanical femur strength and trabecular bone microarchitecture deterioration prevention. In vitro experiments revealed that the actions of DRTF on regulating osteoblastic activities were mediated by the estrogen receptor (ER dependent pathway. Our data also demonstrated that DRTF inhibited osteoclastogenesis via up-regulating osteoprotegrin (OPG, as well as down-regulating receptor activator of NF–κB ligand (RANKL expression. In conclusion, this study indicated that DRTF treatment effectively suppressed bone mass loss in an ovariectomized rat model, and in vitro evidence suggested that the effects were exerted through actions on both osteoblasts and osteoclasts. Keywords: Osteoporosis, Osteoblast, Osteoclast, Ovariectomy, Drynariae Rhizoma

Protective Effects of Vildagliptin against Pioglitazone-Induced Bone Loss in Type 2 Diabetic Rats.

Science.gov (United States)

Eom, Young Sil; Gwon, A-Ryeong; Kwak, Kyung Min; Kim, Ju-Young; Yu, Seung Hee; Lee, Sihoon; Kim, Yeun Sun; Park, Ie Byung; Kim, Kwang-Won; Lee, Kiyoung; Kim, Byung-Joon

2016-01-01

Long-term use of thiazolidinediones (TZDs) is associated with bone loss and an increased risk of fracture in patients with type 2 diabetes (T2DM). Incretin-based drugs (glucagon-like peptide-1 (GLP-1) agonists and dipeptidylpeptidase-4 (DPP-4) inhibitors) have several benefits in many systems in addition to glycemic control. In a previous study, we reported that exendin-4 might increase bone mineral density (BMD) by decreasing the expression of SOST/sclerostin in osteocytes in a T2DM animal model. In this study, we investigated the effects of a DPP-4 inhibitor on TZD-induced bone loss in a T2DM animal model. We randomly divided 12-week-old male Zucker Diabetic Fatty (ZDF) rats into four groups; control, vildagliptin, pioglitazone, and vildagliptin and pioglitazone combination. Animals in each group received the respective treatments for 5 weeks. We performed an intraperitoneal glucose tolerance test (IPGTT) before and after treatment. BMD and the trabecular micro-architecture were measured by DEXA and micro CT, respectively, at the end of the treatment. The circulating levels of active GLP-1, bone turnover markers, and sclerostin were assayed. Vildagliptin treatment significantly increased BMD and trabecular bone volume. The combination therapy restored BMD, trabecular bone volume, and trabecular bone thickness that were decreased by pioglitazone. The levels of the bone formation marker, osteocalcin, decreased and that of the bone resorption marker, tartrate-resistant acid phosphatase (TRAP) 5b increased in the pioglitazone group. These biomarkers were ameliorated and the pioglitazone-induced increase in sclerostin level was lowered to control values by the addition of vildagliptin. In conclusion, our results indicate that orally administered vildagliptin demonstrated a protective effect on pioglitazone-induced bone loss in a type 2 diabetic rat model.

Total glucosides of paeony prevents juxta-articular bone loss in experimental arthritis

OpenAIRE

Wei, Chen Chao; You, Fan Tian; Mei, Li Yu; Jian, Sun; Qiang, Chen Yong

2013-01-01

Background Total glucosides of paeony (TGP) is a biologically active compound extracted from Paeony root. TGP has been used in rheumatoid arthritis therapy for many years. However, the mechanism by which TGP prevents bone loss has been less explored. Methods TGP was orally administered for 3?months to New Zealand rabbits with antigen-induced arthritis (AIA). Digital x-ray knee images and bone mineral density (BMD) measurements of the subchondral knee bone were performed before sacrifice. Chon...

Dietary flavonoid kaempferol inhibits glucocorticoid-induced bone loss by promoting osteoblast survival.

Science.gov (United States)

Adhikary, Sulekha; Choudhary, Dharmendra; Ahmad, Naseer; Karvande, Anirudha; Kumar, Avinash; Banala, Venkatesh Teja; Mishra, Prabhat Ranjan; Trivedi, Ritu

2018-02-13

Kaempferol, a dietary flavonoid found in fruits and vegetables, has been reported to reverse osteopenic condition in ovariectomized rats. Because kaempferol is endowed with osteogenic activity, the aim of this study was to determine whether it has a beneficial effect on glucocorticoid (GC)-induced bone loss. Adult female rats were divided into four groups as control (vehicle; distilled water), methylprednisolone (MP; 5 mg•kg•d, subcutaneously), MP + kaempferol (5 mg•kg•d, oral), and MP + human parathyroid 1-34 (30 µg/kg, 5 times/wk, subcutaneously) and treated for 4 wk. To study the antagonizing effect of kaempferol on GC-induced inhibition of fracture healing, drill-hole injury was performed on control and GC-treated rats. An oral dose of kaempferol was given for 14 d to observe the effect on callus formation at the site of injury. After treatment, bones were collected for further analysis. GC was associated with a decreased bone mineral density and impaired bone microarchitecture parameters. Consumption of kaempferol induced bone-sparing effects in GC-induced osteopenic condition. Additionally, improved callus formation at site of drill injury in femur diaphysis was observed with kaempferol consumption in animals on GC. Consistent with the in vivo data, kaempferol elicited a higher expression of osteogenic markers in vitro and antagonized the apoptotic effect of dexamethasone on calvarial osteoblasts. These results suggested that kaempferol reduced GC-induced bone loss and enhanced bone regeneration at fractured site, thus emphasizing the positive role of flavonoids on bone health. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of Cistanches Herba Aqueous Extract on Bone Loss in Ovariectomized Rat

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Zaiguo Huang

2011-08-01

Full Text Available To assess the ability of traditional Chinese medicine Cistanches Herba extract (CHE to prevent bone loss in the ovariectomized (OVX rat, Cistanches Herba extract (CHE was administered intragastrically to the rats. Female rats were anesthetized with pentobarbital sodium (40 mg kg−1, i.p., and their ovaries were removed bilaterally. The rats in the sham-operated group were anesthetized, laparotomized, and sutured without removing their ovaries. After 1 week of recovery from surgery, the OVX rats were randomly divided into three groups and orally treated with H2O (OVX group or CHE (100 or 200 mg kg−1 daily for 3 months. The sham-operated group (n = 8 was orally treated with H2O. After 3 months, the total body bone mineral density (BMD, bone mineral content (BMC, Bone biomechanical index, blood mineral levels and blood antioxidant enzymes activities were examined in sham-operated, ovariectomized and Cistanches Herba extract treated rats. Results showed that Cistanches Herba extract treatment significantly dose-dependently enhanced bone mineral density (BMD, bone mineral content (BMC, maximum load, displacement at maximum load, stress at maximum load, load at auto break, displacement at auto break, and stress at auto break, and blood antioxidant enzymes activities, decreased blood Ca, Zn and Cu levels compared to the OVX group. This experiment demonstrates that the administration of Cistanches Herba extract to ovariectomized rats reverses bone loss and prevents osteoporosis.

Ethanol Extract of Atractylodes macrocephala Protects Bone Loss by Inhibiting Osteoclast Differentiation

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Youn-Hwan Hwang

2013-06-01

Full Text Available The rhizome of Atractylodes macrocephala has been used mainly in Traditional Chinese Medicine for invigorating the functions of the stomach and spleen. In the present study, we investigated the inhibitory effect of the 70% ethanol extract of the rhizome of Atractylodes macrocephala (AMEE on osteoclast differentiation. We found that AMEE inhibits osteoclast differentiation from its precursors induced by receptor activator of nuclear factor-κB ligand (RANKL, an essential cytokine required for osteoclast differentiation. AMEE attenuated RANKL-induced activation of NF-κB signaling pathway, subsequently inhibiting the induction of osteoclastogenic transcription factors, c-Fos and nuclear factor of activated T cells cytoplasmic 1. Consistent with the in vitro results, administration of AMEE protected RANKL-induced bone loss in mice. We also identified atractylenolide I and II as active constituents contributing to the anti-osteoclastogenic effect of AMEE. Taken together, our results demonstrate that AMEE has a protective effect on bone loss via inhibiting osteoclast differentiation and suggest that AMEE may be useful in preventing and treating various bone diseases associated with excessive bone resorption.

Proximal alveolar bone loss in a longitudinal radiographic investigation

International Nuclear Information System (INIS)

Lavstvedt, S.; Bolin, A.; Henrikson, C.O.; Carstensen, J.

1986-01-01

A longitudinal radiographic investigation was made of the progression of the proximal alveolar bone loss over a 10-year period (1970-1980). The material was unselected and consisted of 669 individuals in the county of Stockholm. 61 individuals were randomly selected for evaluation of a recording system using alternative methods of measurement, and 90% of the measurement sites could then be assessed. The correlations between some of the methods were high, such as between measurement of alveolar bone height and root length and between aleveolar bone height and tooth length. To reduce the number of measurements, a partial recording was made, giving a high correlation coefficient between the partial recording and total recording. When five measurement sites were used, the correlation coefficient was 0.96, and a slight increase of the coefficient was obtained when using additional sites

Correlation analysis of alveolar bone loss in buccal/palatal and proximal surfaces in rats

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Carolina Barrera de Azambuja

2012-12-01

Full Text Available The aim was to correlate alveolar bone loss in the buccal/palatal and the mesial/distal surfaces of upper molars in rats. Thirty-three, 60-day-old, male Wistar rats were divided in two groups, one treated with alcohol and the other not treated with alcohol. All rats received silk ligatures on the right upper second molars for 4 weeks. The rats were then euthanized and their maxillae were split and defleshed with sodium hypochlorite (9%. The cemento-enamel junction (CEJ was stained with 1% methylene blue and the alveolar bone loss in the buccal/palatal surfaces was measured linearly in 5 points on standardized digital photographs. Measurement of the proximal sites was performed by sectioning the hemimaxillae, restaining the CEJ and measuring the alveolar bone loss linearly in 3 points. A calibrated and blinded examiner performed all the measurements. Intraclass Correlation Coefficient revealed values of 0.96 and 0.89 for buccal/lingual and proximal surfaces, respectively. The Pearson Correlation Coefficient (r between measurements in buccal/palatal and proximal surfaces was 0.35 and 0.05 for the group treated with alcohol, with and without ligatures, respectively. The best correlations between buccal/palatal and proximal surfaces were observed in animals not treated with alcohol, in sites both with and without ligatures (r = 0.59 and 0.65, respectively. A positive correlation was found between alveolar bone loss in buccal/palatal and proximal surfaces. The correlation is stronger in animals that were not treated with alcohol, in sites without ligatures. Areas with and without ligature-induced periodontal destruction allow detection of alveolar bone loss in buccal/palatal and proximal surfaces.

Inducible nitric oxide synthase mediates bone loss in ovariectomized mice.

NARCIS (Netherlands)

Cuzzocrea, S.; Mazzon, E.; Dugo, L.; Genovese, T.; Paola, R. Di; Ruggeri, Z.; Vegeto, E.; Caputi, A.P.; Loo, F.A.J. van de; Puzzolo, D.; Maggi, A.

2003-01-01

Several clinical studies have shown that bone loss may be attributed to osteoclast recruitment induced by mediators of inflammation. In different experimental paradigms we have recently demonstrated that estrogen exhibits antiinflammatory activity by preventing the induction of inducible nitric

Cigarette smoke inhalation increases the alveolar bone loss caused by primary occlusal trauma in a rat model.

Science.gov (United States)

Campos, M L G; Corrêa, M G; Júnior, F H N; Casati, M Z; Sallum, E A; Sallum, A W

2014-04-01

Occlusal trauma (OT) and smoking are both factors that alter alveolar bone metabolism and therefore could synergistically act on alveolar bone loss. The aim of this experimental study was to evaluate the influence of short-term cigarette smoke inhalation (CSI) on inter-radicular alveolar bone loss promoted by primary OT in a rat model. Forty-eight animals were randomly assigned to one of three groups based on treatment type: OT + CSI (n = 16), animals were exposed to CSI three times per day, for 8 min per exposure, and they concomitantly received unilateral vertical augmentation creating an occlusal interference inducing experimental OT; OT (n = 16), animals received only unilateral vertical augmentation; negative control (NC; n = 16), animals maintained for equal periods to achieve periodontal baseline values of periodontal ligament dimension. Each group was divided into two subgroups (n = 8) based on treatment length: 7 or 14 d. After 7 d, the OT + CSI group exhibited significantly higher bone loss compared to the NC group (p = 0.0022). After 14 d, the OT (p < 0.0001) and OT + CSI (p < 0.0001) groups presented significantly higher bone loss compared to the NC group, and OT + CSI resulted in significantly higher bone loss than OT alone (p = 0.0241). The number of tartrate-resistant acid phosphatase-positive cells on the linear surface of the bone crest after 7 d was significantly higher in the OT + CSI group as compared to the NC and OT groups (p < 0.0001 and p = 0.0045, respectively) and remained significantly higher in the OT + CSI group after 14 d, compared to the OT group (p < 0.0001). Short-term CSI increases early bone loss in association with OT after 7 d, and this worsens in severity after 14 d of exposure. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mandibular atrophy and metabolic bone loss. Endocrinology, radiology and histomorphometry

NARCIS (Netherlands)

Habets, L. L.; Bras, J.; Borgmeyer-Hoelen, A. M.

1988-01-01

In 11 edentulous patients with a severe atrophy of the mandible and submitted for ridge augmentation, endocrinological, radiological and histomorphometrical studies were carried out. The results showed that metabolic bone loss, histologically in nearly all patients characterized as a disturbance in

Evaluation of the Survival Rate and Bone Loss of Implants with Various Lengths

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AR. Rokn

2006-12-01

Full Text Available Statement of Problem: The replacement of missing teeth with implant-associated restorations has become a widely used treatment modality in recent years. The length of dental implants may be a critical factor in achieving and maintaining osseointegration.Purpose: The aim of this study was to evaluate the survival rate and bone loss of dental implants with different lengthsMaterials and Methods: A retrospective cohort study was performed on 60 ITI-system implants, evenly distributed into three groups including 8, 10 and 12 mm high implants in the posterior segments of both jaws. Demographic information, oral hygiene,cigarette smoking, implant length, duration of implant placement (at least 24 months,bleeding on probing index and pocket probing depth were recorded for all participants.Bone loss was calculated using pre- and post-operative panoramic radiographs.Results: The mean rate of bone loss was different among the three groups and were found to be 0.21 (0.45, 0.3 (0.41 and 0.43 (0.55 mm in the 8, 10, and 12 mm high implants, respectively. Neither mean bone loss nor bleeding on probing index showed significant differences with implant length. A significant correlation was found between implant length and pocket probing depth (P<0.0001.Conclusion: The results of this study suggest that both short (8 mm high and long (10 or 12 mm high implants may be used with nearly equal success rates in the posterior segments of the jaws.

Use of 3D MR reconstructions in the evaluation of glenoid bone loss: a clinical study

International Nuclear Information System (INIS)

Gyftopoulos, Soterios; Beltran, Luis S.; Yemin, Avner; Recht, Michael P.; Strauss, Eric; Meislin, Robert; Jazrawi, Laith

2014-01-01

To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss. (orig.)

Use of 3D MR reconstructions in the evaluation of glenoid bone loss: a clinical study

Energy Technology Data Exchange (ETDEWEB)

Gyftopoulos, Soterios; Beltran, Luis S.; Yemin, Avner; Recht, Michael P. [NYU Langone Medical Center, Department of Radiology, New York, NY (United States); Strauss, Eric; Meislin, Robert; Jazrawi, Laith [NYU Langone Medical Center, Center for Musculoskeletal Care, Department of Orthopaedic Surgery, New York, NY (United States)

2014-02-15

To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss. (orig.)

Doxorubicin-mediated bone loss in breast cancer bone metastases is driven by an interplay between oxidative stress and induction of TGFβ.

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Tapasi Rana

Full Text Available Breast cancer patients, who are already at increased risk of developing bone metastases and osteolytic bone damage, are often treated with doxorubicin. Unfortunately, doxorubicin has been reported to induce damage to bone. Moreover, we have previously reported that doxorubicin treatment increases circulating levels of TGFβ in murine pre-clinical models. TGFβ has been implicated in promoting osteolytic bone damage, a consequence of increased osteoclast-mediated resorption and suppression of osteoblast differentiation. Therefore, we hypothesized that in a preclinical breast cancer bone metastasis model, administration of doxorubicin would accelerate bone loss in a TGFβ-mediated manner. Administration of doxorubicin to 4T1 tumor-bearing mice produced an eightfold increase in osteolytic lesion areas compared untreated tumor-bearing mice (P = 0.002 and an almost 50% decrease in trabecular bone volume expressed in BV/TV (P = 0.0005, both of which were rescued by anti-TGFβ antibody (1D11. Doxorubicin, which is a known inducer of oxidative stress, decreased osteoblast survival and differentiation, which was rescued by N-acetyl cysteine (NAC. Furthermore, doxorubicin treatment decreased Cu-ZnSOD (SOD1 expression and enzyme activity in vitro, and treatment with anti-TGFβ antibody was able to rescue both. In conclusion, a combination therapy using doxorubicin and anti-TGFβ antibody might be beneficial for preventing therapy-related bone loss in cancer patients.

Proximal alveolar bone loss in a longitudinal radiographic investigation

International Nuclear Information System (INIS)

Bolin, A.; Lavstedt, S.; Henrikson, C.O.; Frithiof, L.

1986-01-01

The difference in proximal alveolar bone height between 1970 and 1980, the ''ABD index'', has been measured longitudinally in radiographs from an unselected material. The group constitutes 406 individuals born in 1904 - 1952 in the county of Stockholm. 13 of 18 predictors determined in 1970 were significantly related to the ABD index in the simple correlation analyses. The predictor ''the alveolar bone loss 1970'' (ABL index 1970) had the strongest correlation to the ABD index. In the stepwise multiple regression analysis the predictor ABL index 1970 and three other predictors reached significant levels. These were age, number of lost teeth and Russell's Periodontal Index

Irreversible climate change due to carbon dioxide emissions

Science.gov (United States)

Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

2009-01-01

The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

Donepezil prevents RANK-induced bone loss via inhibition of osteoclast differentiation by downregulating acetylcholinesterase

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Tsuyoshi Sato

2015-09-01

Conclusions: AChE promotes osteoclast differentiation in vitro. Donepezil inhibits osteoclast function in vitro and prevents bone loss by suppressing bone resorption in vivo, suggesting the possibility that donepezil reduces fracture risk in patients with Alzheimer's disease.

Patterns of bone loss around teeth restored with endodontic posts

NARCIS (Netherlands)

Katsamakis, S.; Timmerman, M.; van der Velden, U.; de Cleen, M.; van der Weijden, F.

2009-01-01

Objectives: This retrospective study described the pattern of bone loss around teeth with endodontic posts in periodontitis patients, and compared it with contra-lateral teeth without posts. Material and Methods: From full-mouth radiographic surveys of 146 periodontitis patients (35 years), 194

Digital radiographic evaluation of alveolar bone loss, density and lamina dura integrity on post splinting mandibular anterior with chronic periodontitis

Science.gov (United States)

Rafini, F.; Priaminiarti, M.; Sukardi, I.; Lessang, R.

2017-08-01

The healing of periodontal splinting can be detected both with clinical and radiographic examination. In this study, the alveolar bone was evaluated by radiographic digital periapical analysis. Periodontal tooth splinting is periodontal support therapy used to prevent periodontal injury during repair and regeneration of periodontal therapy. Radiographic digital periapical analysis of alveolar bone in the mandibular anterior region with chronic periodontitis and 2/3 cervical bone loss after three months of periodontal splinting. Eighty four proximal site (43 mesial and 41 distal) from 16 patients with chronic periodontitis and treated with spinting were examined by taking periapical digital radiographic at day 1 and 91. The bone loss, bone density and utility of lamina dura were evaluated. The statistical analysis after three months evaluation using T-test for bone loss, Wilcoxon sign rank test for bone density and utility lamina dura showed no significantly differences (pchronic periodontitis with 2/3 alveolar bone loss after three months splinting.

Marginal Bone Loss Around Early-Loaded SLA and SLActive Implants: Radiological Follow-Up Evaluation Up to 6.5 Years.

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Şener-Yamaner, Işil Damla; Yamaner, Gökhan; Sertgöz, Atilla; Çanakçi, Cenk Fatih; Özcan, Mutlu

2017-08-01

The aim of this study was to compare marginal bone loss around early-loaded SLA and SLActive tissue-level implants (Straumann Dental Implants; Institut Straumann AG, Basel, Switzerland) after a mean of 81-month follow-up period. One hundred seven SLA and 68 SLActive implants were placed in 55 patients and loaded with final restoration after 8 and 3 weeks of healing time, respectively. Marginal bone loss around implants was determined radiographically at initial and after a mean observation time ranging between 20 and 81 months. The effect of location (mandible vs maxilla), smoking habit, sex, implant length and diameter, and the type of prosthesis on the marginal bone loss was evaluated. The overall cumulative survival rate was 98.2% being 99% for SLA implants and 97% for SLActive implants. After 20-month follow-up period, mean marginal bone loss values for the SLA and SLActive implants were 0.24 and 0.17 mm, respectively. After 81 months, mean marginal bone loss for the SLA and SLActive implants reached 0.71 and 0.53 mm, respectively. Marginal bone loss was affected by the length and type of implant and patients' smoking habit after a mean observation time of 20 months. However, none of the parameters had any significant effect on the marginal bone loss after a follow-up period of 81 months. With both SLA and SLActive implants, successful clinical results could be achieved up to 6.5 years of follow-up period.

Local vibration enhanced the efficacy of passive exercise on mitigating bone loss in hindlimb unloading rats

Science.gov (United States)

Huang, Yunfei; Luan, Huiqin; Sun, Lianwen; Bi, Jingfang; Wang, Ying; Fan, Yubo

2017-08-01

Spaceflight induced bone loss is seriously affecting astronauts. Mechanical stimulation from exercise has been shown to restrain bone resorption as well as improve bone formation. Current exercise countermeasures in space cannot prevent it completely. Active exercise may convert to passive exercise in some ways because of the loss of gravity stimulus and inertia of exercise equipment. The aim of this study was to compare the efficacy of passive exercise or/and local vibration on counteracting the deterioration of the musculoskeletal system, including bone, muscle and tendons in tail-suspended rats. We hypothesized that local vibration could enhance the efficacy of passive exercise on countering bone loss. 40 Sprague Dawley rats were randomly distributed into five groups (n = 8, each): tail-suspension (TS), TS+35 Hz vibration (TSV), TS + passive exercise (TSP), TS + passive exercise coupled with 35 Hz vibration (TSPV) and control (CON). Passive exercise or/and local vibration was performed for 21 days. On day 0 and 21, bone mineral density (BMD) was observed by dual energy X-ray absorptiometry (DXA), and trabecular microstructure was evaluated by microcomputer tomography (μCT) analysis in vivo. Mechanical properties of tibia and tendon were determined by a mechanical testing system. Soleus and bone ash weight was tested by an electronic balance. Results showed that the passive exercise could not prevent the decrease of trabecular BMD, microstructure and bone ash weight induced by TS, whereas vibration and passive exercise coupled with local vibration (PV) could. Biomechanical properties of the tibia and tendon in TSPV group significantly increased compared with TS group. In summary, PV in this study was the best method in preventing weightlessness-induced bone loss. Consistent with our hypothesis, local vibration partly enhanced the effect of passive exercise. Furthermore, this study will be useful in improving countermeasure for astronauts, but also for the

Rhizoma Dioscoreae extract protects against alveolar bone loss in ovariectomized rats via microRNAs regulation.

Science.gov (United States)

Zhang, Zhiguo; Song, Changheng; Zhang, Fangzhen; Xiang, Lihua; Chen, Yanjing; Li, Yan; Pan, Jinghua; Liu, Hong; Xiao, Gary Guishan; Ju, Dahong

2015-02-16

The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with ovariectomy-induced bone loss. Female Wistar rats underwent either ovariectomy or sham operation (SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX), estradiol valerate (EV), or RDE. After treatments, the bone mineral density (BMD) and the three-dimensional microarchitecture of the alveolar bone were analyzed to assess bone mass. Microarrays were used to evaluate microRNA expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of microRNAs was validated using real-time quantitative RT-PCR (qRT-PCR), and the target genes of validated microRNAs were predicted and further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using qRT-PCR. Our results show that RDE inhibits alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 8 microRNAs and downregulated expression levels of 8 microRNAs in the alveolar bone in the microarray analysis. qRT-PCR helped validate 13 of 16 differentially expressed microRNAs, and 114 putative target genes of the validated microRNAs were retrieved. The IPA showed that these putative target genes had the potential to code for proteins that were involved in the transforming growth factor (TGF)-β/bone morphogenetic proteins (BMPs)/Smad signaling pathway (Tgfbr2/Bmpr2, Smad3/4/5, and Bcl-2) and interleukin (IL)-6/oncostatin M (OSM)/Jak1/STAT3 signaling pathway (Jak1, STAT3, and Il6r). These experiments revealed that RDE could inhibit ovariectomy-induced alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may involve the simultaneous inhibition of bone formation and bone resorption, which is associated with modulation of the TGF-β/BMPs/Smad and the IL-6/OSM/Jak1/STAT3 signaling pathways via microRNA regulation.

P2X7 receptor regulates osteoclast function and bone loss in a mouse model of osteoporosis.

Science.gov (United States)

Wang, Ning; Agrawal, Ankita; Jørgensen, Niklas Rye; Gartland, Alison

2018-02-22

Post-menopausal osteoporosis is a condition that affects millions worldwide and places a huge socio-economic burden on society. Previous research has shown an association of loss of function SNPs in the gene for the purinergic receptor P2X7R with low bone mineral density, increased rates of bone loss and vertebral fractures in post-menopausal women. In this study we use a mouse model of oestrogen deficiency-induced bone loss and the BALB/cJ P2X7R -/- to show that absence of the P2X7R resulted in increased bone loss. Osteoclast precursors were isolated from both BALB/cJ P2X7R -/- and BALB/cJ P2X7R +/+ mice and then cultured in vitro to form mature resorbing osteoclasts. The BALB/cJ P2X7R -/- derived precursors generated slightly more osteoclasts but with a significant reduction in the amount of resorption per osteoclast. Furthermore, when using modified culture conditions osteoclast activity was additionally increased in the absence of the P2X7R suggest that P2X7R may regulate the lifespan and activity of osteoclasts. Finally using mechanical loading as an anabolic stimulus for bone formation, we demonstrated that the increased oestrogen-deficient bone loss could be rescued, even in the absence of P2X7R. This study paves the way for clinical intervention for women with post-menopausal osteoporosis and P2XR7 loss of function polymorphisms.

Vegetarianism, bone loss, fracture and vitamin D: a longitudinal study in Asian vegans and non-vegans.

Science.gov (United States)

Ho-Pham, L T; Vu, B Q; Lai, T Q; Nguyen, N D; Nguyen, T V

2012-01-01

The effect of vegan diet on bone loss has not been studied. The aim of this study was to examine the association between veganism and bone loss in postmenopausal women. The study was designed as a prospective longitudinal investigation with 210 women, including 105 vegans and 105 omnivores. Femoral neck (FN) bone mineral density (BMD) was measured in 2008 and 2010 by dual-energy X-ray absorptiometry (Hologic QDR4500). The incidence of vertebral fracture was ascertained by X-ray report. Serum levels of C-terminal telopeptide of type I collagen (βCTX) and N-terminal propeptide of type I procollagen (PINP) were measured by Roche Elecsys assays. Serum concentration of 25-hydroxyvitamin D and parathyroid hormone were measured by electrochemiluminescence. Among the 210 women who initially participated in the study in 2008, 181 women had completed the study and 29 women were lost to follow-up. The rate of loss in FN BMD was -1.91±3.45%/year in omnivores and -0.86±3.81%/year (P=0.08) in vegans. Lower body weight, higher intakes of animal protein and lipid, and corticosteroid use were associated with greater rate of bone loss. The 2-year incidence of fracture was 5.7% (n=5/88) in vegans, which was not significantly different from omnivores (5.4%, n=6/93). There were no significant differences in βCTX and PINP between vegans and omnivores. The prevalence of vitamin D insufficiency in vegans was higher than in omnivores (73% versus 46%; P=0.0003). Vegan diet did not have adverse effect on bone loss and fracture. Corticosteroid use and high intakes of animal protein and animal lipid were negatively associated with bone loss.

Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats.

Science.gov (United States)

Grubbe, M-C; Thomsen, J S; Nyengaard, J R; Duruox, M; Brüel, A

2014-12-01

Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind limb. Sixty female Wistar rats, 14 weeks old, were divided into the following groups: baseline, controls, BTX, BTX+GH, and GH. GH was given at a dosage of 5 mg/kg/d for 4 weeks. Compared with controls, BTX resulted in lower periosteal bone formation rate (BFR/BS,-79%, Pbone mineral density (aBMD, -13%, Pbone volume (BV/TV, -26%, Pbone strength (-12%, Pbone strength was found. In addition, GH partly prevented loss of muscle mass (+29% vs. BTX, P<0.001), and tended to prevent loss of muscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse-induced loss of periosteal BFR/BS at the mid-femur and rectus femoris muscle mass.

Alpha-1 antitrypsin gene therapy prevented bone loss in ovariectomy induced osteoporosis mouse model

Science.gov (United States)

Osteoporosis is a major healthcare burden affecting mostly postmenopausal women characterized by compromised bone strength and increased risk of fragility fracture. Although pathogenesis of this disease is complex, elevated proinflammatory cytokine production is clearly involved in bone loss at meno...

No major effect of estrogen receptor gene polymorphisms on bone mineral density or bone loss in postmenopausal Danish women

DEFF Research Database (Denmark)

Bagger, Y Z; Jørgensen, H L; Heegaard, Anne-Marie

2000-01-01

The polymorphisms of the estrogen receptor (ER) gene defined by the restriction enodonucleases PvuII and XbaI have recently been reported to be associated with bone mineral density (BMD) in postmenopausal women. To investigate the possible relation of the PvuII and XbaI restriction fragment......-length polymorphisms of the ER gene with BMD in Danish postmenopausal women, two studies were undertaken: 1) a cross-sectional study of 499 postmenopausal women, where the ER genotypes and alleles were related to BMD of the hip, spine, and lower forearm; and 2) a longitudinal study of 101 postmenopausal women followed...... up for 18 years. In the latter study, late postmenopausal bone loss in the hip and spine was determined over a period of 6 years in women (mean age of 63 to 69 years), and long-term postmenopausal bone loss in the lower forearm was determined over a period of 18 years in women (mean age of 51 to 69...

Clinical Parameters and Crestal Bone Loss in Internal Versus External Hex Implants at One Year after Loading

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HamidReza Arab

2015-09-01

Full Text Available Introduction: The survival of an implant system is affected by the choice of antirotational design, which can include an external or internal hex. Implant success also is affected by the maintenance of the crestal bone around implants. The aim of present study was to evaluate the crestal bone loss and clinical parameters related to bone loss in patients loaded with an external or internal hex 3i implant (3i Implant Innovation, Palm Beach Gardens, FL, USA. The evaluations were performed one year after loading. Materials and Methods: A total of 39 implants (23 external hex, 16 internal hex were placed randomly in 23 patients (10 male, 13 female by a submerged approach. None of patients had compromised conditions or parafunctional habits. At placement and at one year after loading, periapical radiographs were taken via the parallel method from the implant sites. Results: Crestal bone loss was -0.712±0.831 mm in implants with an internal hex connection and -0.139±0.505 mm in implants with an external hex connection (P≤0.05. No correlation was found between crestal bone loss and parameters such as age, gender, jaw, implant location (anterior, premolar, or molar, implant diameter, or implant length. Conclusions: Crestal bone loss was greater in patients with internal hex 3i implants than in those with external implants. Similar results in other clinical factors were found between the groups.

Rates of bone loss among women initiating antidepressant medication use in midlife.

Science.gov (United States)

Diem, Susan J; Ruppert, Kristine; Cauley, Jane A; Lian, YinJuan; Bromberger, Joyce T; Finkelstein, Joel S; Greendale, Gail A; Solomon, Daniel H

2013-11-01

Concern has been raised that medications that block serotonin reuptake may affect bone metabolism, resulting in bone loss. The aim of the study was to compare annual bone mineral density (BMD) changes among new users of selective serotonin reuptake inhibitors (SSRIs), new users of tricyclic antidepressants (TCAs), and nonusers of antidepressant medications. We conducted a prospective cohort study at five clinical centers in the United States. The study included 1972 community-dwelling women, aged 42 years and older, enrolled in the Study of Women's Health Across the Nation (SWAN). The use of antidepressant medications was assessed by interview and verified from medication containers at annual visits. Subjects were categorized as nonusers (no SSRI or TCA use at any examination), SSRI users (initiated SSRI use after the baseline SWAN visit), or TCA users (initiated TCA use after the baseline visit), using a computerized dictionary to categorize type of medication. BMD at the lumbar spine, total hip, and femoral neck was measured using dual-energy x-ray absorptiometry at annual visits. BMD was compared among 311 new users of SSRIs, 71 new users of TCAs, and 1590 nonusers. After adjustment for potential confounders, including age, race, body mass index, menopausal status, and hormone therapy use, mean lumbar spine BMD decreased on average 0.68% per year in nonusers, 0.63% per year in SSRI users (P = .37 for comparison to nonusers), and 0.40% per year in TCA users (P = .16 for comparison to nonusers). At the total hip and femoral neck, there was also no evidence that SSRI or TCA users had an increased rate of bone loss compared with nonusers. Results were similar in subgroups of women stratified by the Center for Epidemiologic Studies Depression Scale (women, use of SSRIs and TCAs was not associated with an increased rate of bone loss at the spine, total hip, or femoral neck.

Muscle changes can account for bone loss after botulinum toxin injection.

Science.gov (United States)

Manske, Sarah L; Boyd, Steven K; Zernicke, Ronald F

2010-12-01

Studies to date have assumed that botulinum toxin type A (BTX) affects bone indirectly, through its action on muscle. We hypothesized that BTX has no discernable effect on bone morphometry, independent of its effect on muscle. Therefore, we investigated whether BTX had an additional effect on bone when combined with tenotomy compared to tenotomy in isolation. Female BALB/c mice (n = 73) underwent one of the following procedures in the left leg: BTX injection and Achilles tenotomy (BTX-TEN), BTX injection and sham surgery (BTX-sham), Achilles tenotomy (TEN), or sham surgery (sham). BTX groups were injected with 20 μL of BTX (1 U/100 g) in the posterior lower hindlimb. At 4 weeks, muscle cross-sectional area (MCSA) and tibial bone morphometry were assessed using micro-CT. Each treatment, other than sham, resulted in significant muscle and bone loss (P properties. We found that BTX injection resulted in more adverse muscle and bone effects than tenotomy and that effects were amplified when the procedures were combined. However, between-group differences in bone could be accounted for by MCSA. We conclude that any independent effect of BTX on bone morphometry is likely small or negligible compared with the effect on muscle.

Coincidence of calcified carotid atheromatous plaque, osteoporosis, and periodontal bone loss in dental panoramic radiographs

International Nuclear Information System (INIS)

Ramesh, Aruna; Ganguly, Rumpa; Soroushian, Sheila

2013-01-01

This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, 'With CCAP' and 'Without CCAP', there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

NF-κB decoy oligodeoxynucleotide mitigates wear particle-associated bone loss in the murine continuous infusion model.

Science.gov (United States)

Lin, Tzu-Hua; Pajarinen, Jukka; Sato, Taishi; Loi, Florence; Fan, Changchun; Córdova, Luis A; Nabeshima, Akira; Gibon, Emmanuel; Zhang, Ruth; Yao, Zhenyu; Goodman, Stuart B

2016-09-01

Total joint replacement is a cost-effective surgical procedure for patients with end-stage arthritis. Wear particle-induced chronic inflammation is associated with the development of periprosthetic osteolysis. Modulation of NF-κB signaling in macrophages, osteoclasts, and mesenchymal stem cells could potentially mitigate this disease. In the current study, we examined the effects of local delivery of decoy NF-κB oligo-deoxynucleotide (ODN) on wear particle-induced bone loss in a murine continuous femoral particle infusion model. Ultra-high molecular weight polyethylene particles (UHMWPE) with or without lipopolysaccharide (LPS) were infused via osmotic pumps into hollow titanium rods placed in the distal femur of mice for 4weeks. Particle-induced bone loss was evaluated by μCT, and immunohistochemical analysis of sections from the femur. Particle infusion alone resulted in reduced bone mineral density and trabecular bone volume fraction in the distal femur. The decoy ODN reversed the particle-associated bone volume fraction loss around the implant, irrespective of the presence of LPS. Particle-infusion with LPS increased bone mineral density in the distal femur compared with particle-infusion alone. NF-κB decoy ODN reversed or further increased the bone mineral density in the femur (3-6mm from the distal end) exposed to particles alone or particles plus LPS. NF-κB decoy ODN also inhibited macrophage infiltration and osteoclast number, but had no significant effects on osteoblast numbers in femurs exposed to wear particles and LPS. Our study suggests that targeting NF-κB activity via local delivery of decoy ODN has great potential to mitigate wear particle-induced osteolysis. Total joint replacement is a cost-effective surgical procedure for patients with end-stage arthritis. Chronic inflammation is crucial for the development of wear particle-associated bone loss. Modulation of NF-κB signaling in macrophages (pro-inflammatory cells), osteoclasts (bone

Effect of an estrogen-deficient state and alendronate therapy on bone loss resulting from experimental periapical lesions in rats.

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Xiong, Haofei; Peng, Bin; Wei, Lili; Zhang, Xiaolei; Wang, Li

2007-11-01

The aim of the research was to evaluate the impact of an estrogen-deficient state and alendronate (ALD) therapy on bone loss resulting from experimental periapical lesions in rats. Periapical lesions were induced on ovariectomized (OVX) and sham-ovariectomized (Sham) rats. After sample preparation, histologic and radiographic examination for periapical bone loss area and an enzyme histochemical test for tartrate-resistant acid phosphatase (TRAP) were performed. The results showed that OVX significantly increased bone loss resulting from periradicular lesions. After daily subcutaneous injection of ALD, the bone loss area and the number of TRAP-positive cells (osteoclasts) were reduced. These findings suggested that alendronate may protect against increased bone loss from experimental periapical lesions in estrogen-deficient rats. Given recent recognition of adverse effects of bisphosphonates, including an increased risk for osteonecrosis, the findings from this study should not be interpreted as a new indication for ALD treatment. However, they may offer insight into understanding and predicting outcomes in female postmenopausal patients already on ALD therapy for medical indications.

Mitochondria related peptide MOTS-c suppresses ovariectomy-induced bone loss via AMPK activation

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Ming, Wei, E-mail: weiming@xiyi.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Department of Pharmacology, Xi’an Medical University, Xi’an 710021 (China); Lu, Gan, E-mail: leonming99@163.com [Department of Gynecology of Shaanxi Provincial People’s Hospital, Xi’an, 710068 (China); Xin, Sha, E-mail: 248967979@qq.com [Institute of Orthopedic Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710032 (China); Huanyu, Lu, E-mail: 2366927258@qq.com [Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi’an 710032 (China); Yinghao, Jiang, E-mail: jiangyh@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Xiaoying, Lei, E-mail: leixiaoy@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Chengming, Xu, E-mail: chengmingxu@yeah.net [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Banjun, Ruan, E-mail: running@163.com [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); Li, Wang, E-mail: wanglifw@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, Fourth Military Medical University, Xi’an 710032 (China); and others

2016-08-05

Therapeutic targeting bone loss has been the focus of the study in osteoporosis. The present study is intended to evaluate whether MOTS-c, a novel mitochondria related 16 aa peptide, can protect mice from ovariectomy-induced osteoporosis. After ovary removal, the mice were injected with MOTS-c at a dose of 5 mg/kg once a day for 12 weeks. Our results showed that MOTS-c treatment significantly alleviated bone loss, as determined by micro-CT examination. Mechanistically, we found that the receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclast differentiation was remarkably inhibited by MOTS-c. Moreover, MOTS-c increased phosphorylated AMPK levels, and compound C, an AMPK inhibitor, could partially abrogate the effects of the MOTS-c on osteoclastogenesis. Thus, our findings provide evidence that MOTS-c may exert as an inhibitor of osteoporosis via AMPK dependent inhibition of osteoclastogenesis. -- Highlights: •MOTS-c decreases OVX-induced bone loss in vivo. •MOTS-c inhibits RANKL-induced osteoclast formation. •MOTS-c inhibits RANKL-induced osteoclast-specific gene expression. •MOTS-c represses osteoclast differentiation via the activation of AMPK.

Mitochondria related peptide MOTS-c suppresses ovariectomy-induced bone loss via AMPK activation

International Nuclear Information System (INIS)

Ming, Wei; Lu, Gan; Xin, Sha; Huanyu, Lu; Yinghao, Jiang; Xiaoying, Lei; Chengming, Xu; Banjun, Ruan; Li, Wang

2016-01-01

Therapeutic targeting bone loss has been the focus of the study in osteoporosis. The present study is intended to evaluate whether MOTS-c, a novel mitochondria related 16 aa peptide, can protect mice from ovariectomy-induced osteoporosis. After ovary removal, the mice were injected with MOTS-c at a dose of 5 mg/kg once a day for 12 weeks. Our results showed that MOTS-c treatment significantly alleviated bone loss, as determined by micro-CT examination. Mechanistically, we found that the receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclast differentiation was remarkably inhibited by MOTS-c. Moreover, MOTS-c increased phosphorylated AMPK levels, and compound C, an AMPK inhibitor, could partially abrogate the effects of the MOTS-c on osteoclastogenesis. Thus, our findings provide evidence that MOTS-c may exert as an inhibitor of osteoporosis via AMPK dependent inhibition of osteoclastogenesis. -- Highlights: •MOTS-c decreases OVX-induced bone loss in vivo. •MOTS-c inhibits RANKL-induced osteoclast formation. •MOTS-c inhibits RANKL-induced osteoclast-specific gene expression. •MOTS-c represses osteoclast differentiation via the activation of AMPK.

Regulatory Effect of Catalpol on Th1/Th2 cells in Mice with Bone Loss Induced by Estrogen Deficiency.

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Lai, Nannan; Zhang, Jianhai; Ma, Xingyan; Wang, Bin; Miao, Xiuming; Wang, Zhaoxia; Guo, Yuqi; Wang, Li; Yao, Chengfang; Li, Xia; Jiang, Guosheng

2015-12-01

Estradiol (E2 ) deficiency can cause bone loss and the skew of Th1/Th2 cells. However, the correlation between the Th1/Th2 cells and the bone loss induced by estrogen deficiency remains unclear. Our aim was to investigate the role of Th1/Th2 in bone loss induced by estrogen deficiency and elucidated the therapeutical effect of catalpol in this condition. Young, sham-operated (Sham), ovariectomized (Ovx), and naturally aged mice, treated with catalpol at different doses or control vehicle, were used in this study as indicated in each experiment. ELISA assay, dual-energy X-ray absorptiometry, and flow cytometry were used to analyze E2 , C-terminal telopeptides of type I collagen (CTx-I), bone mineral density (BMD), and Th1/Th2 subsets, respectively. The mRNA and protein expressions of specific transcription factors for Th1/Th2 cells (T-bet and GATA-3) were analyzed using real-time quantitative PCR and Western blot, respectively. Bone mineral density and E2 levels positively correlated with the proportion of Th2 subset while negatively correlated with that of Th1 subset and the ratio of Th1/Th2. Catalpol alleviated bone loss effectively by regulating Th1/Th2 polarization. Catalpol promoted the expression of Th2-specific transcription factors while inhibited that associated with Th1. Th1/Th2 skew is involved in bone loss induced by estrogen deficiency. Catalpol alleviates bone loss effectively by regulating Th1/Th2 paradigm. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Senescent T-Cells Promote Bone Loss in Rheumatoid Arthritis

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Johannes Fessler

2018-02-01

Full Text Available ObjectiveT-cells are critical players in the pathogenesis of osteoporosis in patients with rheumatoid arthritis (RA. Premature senescence of lymphocytes including the accumulation of senescent CD4+ T-cells is a hallmark feature of RA. Whether T-cell senescence is associated with bone loss in RA patients is elusive so far.MethodsThis includes a prospective study of consecutive patients with RA (n = 107, patients with primary osteopenia/-porosis (n = 75, and healthy individuals (n = 38. Bone mineral density (BMD was determined by dual-energy X-ray absorptiometry scan. Flow cytometry, magnetic-associated cell sorting, and cell culture experiments were performed to analyze the pro-osteoclastic phenotype and the function of senescent CD4+CD28− T-cells.ResultsPatients with osteopenia/-porosis yielded a higher prevalence of senescent CD4+CD28− T-cells than individuals with normal BMD, in the RA, as well as in the non-RA cohort. Receptor activator of nuclear factor kappa-B ligand (RANKL was expressed at higher levels on CD4+CD28− T-cells as compared to CD28+ T-cells. Stimulation with interleukin-15 led to an up-regulation of RANKL expression, particularly on CD28− T-cells. CD4+CD28− T-cells induced osteoclastogenesis more efficiently than CD28+ T-cells.ConclusionOur data indicate that senescent T-cells promote osteoclastogenesis more efficiently than conventional CD28+ T-cells, which might contribute to the pathogenesis of systemic bone loss in RA and primary osteoporosis.

Hwangryun-Haedok-Tang Fermented with Lactobacillus casei Suppresses Ovariectomy-Induced Bone Loss

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Ki-Shuk Shim

2012-01-01

Full Text Available Hwangryun-haedok-tang (HRT is the common recipe in traditional Asian medicine, and microbial fermentation is used for the conventional methods for processing traditional medicine. We investigated the inhibitory effect of the n-butanol fraction of HRT (HRT-BU and fHRT (fHRT-BU on the RANKL-induced osteoclastogenesis in bone-marrow-derived macrophages. mRNA expression of osteoclastogenesis-related genes were evaluated by real-time QPCR. The activation of signaling pathways was determined by western blot analysis. The marker compounds of HRT-BU and fHRT-BU were analyzed by HPLC. The inhibitory effect of HRT or fHRT on ovariectomy-induced bone loss were evaluated using OVX rats with orally administered HRT, fHRT (300, 1000 mg/kg, or its vehicle for 12 weeks. fHRT-BU significantly inhibited RANKL-induced osteoclastogenesis, and phosphorylation of p38, IKKα/β, and NF-κBp65 compared to HRT-BU. In addition, fHRT-BU also significantly inhibited the mRNA expression of Nfκb2, TNF-α, NFATc1, TRAP, ATPv0d2, and cathepsin K. Furthermore, administration of fHRT had a greater effect on the increase of BMD, and greater improved bone microstructure of the femora than that of HRT in ovariectomy rats. This study demonstrated that bacterial fermentation enhances the inhibitory effect of HRT on osteoclastogenesis and bone loss. These results suggest that fermented HRT might have the beneficial effects on bone disease by inhibiting osteoclastogenesis.

Staged Custom, Intramedullary Antibiotic Spacers for Severe Segmental Bone Loss in Infected Total Hip Arthroplasty

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Atul F. Kamath

2011-01-01

Full Text Available Introduction. Total hip arthroplasty (THA infections with severe bone loss pose significant reconstructive challenges. We present our experience with two-stage hip reimplantation using an intramedullary, antibiotic-impregnated nail. Methods. Three patients with infected THA with severe proximal femoral bone loss (Mallory type IIIB or greater were treated using a custom antibiotic spacer. Clinical outcomes and any complications were recorded. Average followup was 49 months from final reimplantation. Results. Mean age at spacer placement (stage 1 was 53 years. The mean Harris Hip Score at final followup was 80. Two patients had asymptomatic heterotopic ossification, and one patient had a 2 cm leg-length discrepancy. Conclusions. A custom intramedullary nail antibiotic spacer is a reliable option in the staged management of the infected THA with severe proximal femoral bone loss. Benefits of this technique include limb salvage with maintenance of leg length, soft tissue tension, and functional status.

Feeding blueberry diets in early life prevent senescence of osteoblasts and bone loss in ovariectomized adult female rats.

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Jian Zhang

Full Text Available Appropriate nutrition during early development is essential for maximal bone mass accretion; however, linkage between early nutrition, childhood bone mass, peak bone mass in adulthood, and prevention of bone loss later in life has not been studied.In this report, we show that feeding a high quality diet supplemented with blueberries (BB to pre-pubertal rats throughout development or only between postnatal day 20 (PND20 and PND34 prevented ovariectomy (OVX-induced bone loss in adult life. This protective effect of BB is due to suppression of osteoblastic cell senescence associated with acute loss of myosin expression after OVX. Early exposure of pre-osteoblasts to serum from BB-fed rats was found to consistently increase myosin expression. This led to maintenance osteoblastic cell development and differentiation and delay of cellular entrance into senescence through regulation of the Runx2 gene. High bone turnover after OVX results in insufficient collagenous matrix support for new osteoblasts and their precursors to express myosin and other cytoskeletal elements required for osteoblast activity and differentiation.These results indicate: 1 a significant prevention of OVX-induced bone loss from adult rats can occur with only 14 days consumption of a BB-containing diet immediately prior to puberty; and 2 the molecular mechanisms underlying these effects involves increased myosin production which stimulates osteoblast differentiation and reduces mesenchymal stromal cell senescence.

Inactivity-induced bone loss is not exacerbated by moderate energy restriction

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Heer, M.; Boese, A.; Baecker, N.; Zittermann, A.; Smith, S. M.

Severe energy restriction leads to decreased bone mineral density (BMD) in postmenopausal women, adolescent females, and in male athletes. Astronauts in space also lose bone mass, and most of them have reduced energy intake (about 25 % below requirements). The aim of our study was to examine if bone loss in space is partly induced by moderate energy restriction. Physiological changes of space flight were simulated by 6 head-down tilt bed rest (HDBR). Nine healthy male subjects (age: 23.6 ± 3.0 years; BMI: 23.0 ± 2.9 kg/m2, mean ± SD) finished four study phases, two of normocaloric nutrition, either ambulatory or HDBR, and two of hypocaloric nutrition, either ambulatory or HDBR. Urine samples (24 h) were analyzed for calcium excretion (UCaV) and bone resorption markers (C-Telopeptide, CTX, and N-Telopeptide, NTX). Serum calcium, parathyroid hormone (PTH) and bone formation markers (Procollagen-I-C-terminal-Peptide, PICP, Procollagen-I-N-terminal-Peptide, PINP, and bone-specific alkaline phosphatase, bAP) were analyzed. No significant changes in serum calcium or PTH were noted either during HDBR or during hypocaloric nutrition. PICP, but not PINP or bAP, decreased significantly during HDBR (normocaloric: prestriction did not exaggerate bone resorption during HDBR.

Comparison of peri-implant bone loss between conventional drilling with irrigation versus low-speed drilling without irrigation.

Science.gov (United States)

Pellicer-Chover, H; Peñarrocha-Oltra, D; Aloy-Prosper, A; Sanchis-Gonzalez, J-C; Peñarrocha-Diago, M-A; Peñarrocha-Diago, M

2017-11-01

To compare the technique of high speed drilling with irrigation and low speed drilling without irrigation in order to evaluate the success rate and peri-implant bone loss at 12 months of follow-up. A randomized, controlled, parallel-group clinical trial was carried out in patients requiring dental implants to rehabilitate their unitary edentulism. Patients were recruited from the Oral Surgery Unit of the University of Valencia (Spain) between September 2014 and August 2015. Patients who met the inclusion criteria were randomized to two groups: group A (high-speed drilling with irrigation) and group B (low-speed drilling without irrigation). The success rate and peri-implant bone loss were recorded at 12 months of follow-up. Twenty-five patients (9 men and 16 women) with 30 implants were enrolled in the study: 15 implants in group A and 15 implants in group B. The mean bone loss of the implants in group A and group B was 0.83 ± 0.73 mm and 0.62 ± 0.70 mm, respectively (p> 0.05). In the maxilla, the bone loss was 1.04 ± 0.63 mm in group A and 0.71 ± 0.36 mm in group B (p> 0.05), while bone loss in the mandible was 0.59 ± 0.80 mm in group A and 0.69 ± 0.77 mm in group B (p> 0.05). The implant success rate at 12 months was 93.3% in group A and 100% in group B. Within the limitations of the study, the low-speed drilling technique presented peri-implant bone loss outcomes similar to those of the conventional drilling technique at 12 months of follow-up.

Bone Loss in the Acute Stage Following Burn Injury - Original Investigation

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Berrin Leblebici

2007-06-01

Full Text Available Aim: The purpose of this study was to determine whether a bone loss occurs during acute period following burn injury or not, and to investigate the effects of various parameters on it. Materials and Methods: This study was conducted on 19 patients, ages between 20 and 50, who had a burn injury with more than %20 of Total Body Surface Area (TBSA. We recorded the patients’ burn cause, localization, percantage, ambulation and functional status. At the end of the first month, we measured bone mıneral densıty of total L1-L4 vertebrae, left distal forearm, left total femur, in all patients. A Z score less than –1 was accepted to be the indicator of bone loss. Results: The mean age of the patients (14 male and 5 female was 33.09±11.61. We found a Z score less then -1 in 68.4% of left distal forearm, 21.1% of left total femur and 36.8% of total L1-L4 vertabrae measurements. There were no significant correlations between TBSA, Functional Ambulatıon Scale and Functional Independence Measure, and Z scores. Conclusion: There is a reduction in Bone Mineral Density in patıents wıth moderate/severe burn ınjuries in the acute period which is not correlated wıth neither TBSA nor functional status. (From the World of Osteoporosis 2007;13:33-6

P2X7 receptor regulates osteoclast function and bone loss in a mouse model of osteoporosis

DEFF Research Database (Denmark)

Wang, Ning; Agrawal, Ankita; Jørgensen, Niklas Rye

2018-01-01

Post-menopausal osteoporosis is a condition that affects millions worldwide and places a huge socio-economic burden on society. Previous research has shown an association of loss of function SNPs in the gene for the purinergic receptor P2X7R with low bone mineral density, increased rates of bone...... loss and vertebral fractures in post-menopausal women. In this study we use a mouse model of oestrogen deficiency-induced bone loss and the BALB/cJ P2X7R-/- to show that absence of the P2X7R resulted in increased bone loss. Osteoclast precursors were isolated from both BALB/cJ P2X7R-/- and BALB/cJ P2X7......R+/+ mice and then cultured in vitro to form mature resorbing osteoclasts. The BALB/cJ P2X7R-/- derived precursors generated slightly more osteoclasts but with a significant reduction in the amount of resorption per osteoclast. Furthermore, when using modified culture conditions osteoclast activity...

Coincidence of calcified carotid atheromatous plaque, osteoporosis, and periodontal bone loss in dental panoramic radiographs

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Ramesh, Aruna; Ganguly, Rumpa [Dept. of Diagnosis and Health Promotion, Division of Oral and Maxillofacial Radiology, Tufts University School of Dental Medicine, Boston (United States); Soroushian, Sheila [Dept. of Orthodontics, Howard University College of Dentistry, Washington, DC(United States)

2013-12-15

This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, 'With CCAP' and 'Without CCAP', there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

Total glucosides of paeony prevents juxta-articular bone loss in experimental arthritis.

Science.gov (United States)

Wei, Chen Chao; You, Fan Tian; Mei, Li Yu; Jian, Sun; Qiang, Chen Yong

2013-07-21

Total glucosides of paeony (TGP) is a biologically active compound extracted from Paeony root. TGP has been used in rheumatoid arthritis therapy for many years. However, the mechanism by which TGP prevents bone loss has been less explored. TGP was orally administered for 3 months to New Zealand rabbits with antigen-induced arthritis (AIA). Digital x-ray knee images and bone mineral density (BMD) measurements of the subchondral knee bone were performed before sacrifice. Chondrocytes were observed using transmission electron microscopy (TEM). Histological analysis and mRNA expression of receptor activator of nuclear factor-B ligand (RANKL) and osteoprotegerin (OPG) were evaluated in joint tissues. The BMD value in TGP rabbits was significantly higher compared with that seen in the AIA model rabbits. In addition, the subchondral bone plate was almost completely preserved by TGP treatment, while there was a decrease in bone plate integrity in AIA rabbits. There was less damage to the chondrocytes of the TGP treated group. Immunohistochemical examination of the TGP group showed that a higher percentage of TGP treated chondrocytes expressed OPG as compared to the chondrocytes isolated from AIA treated animals. In contrast, RANKL expression was significantly decreased in the TGP treated group compared to the AIA group. In support of the immunohistochemistry data, the expression of RANKL mRNA was decreased and OPG mRNA expression was enhanced in the TGP group when compared to that of the AIA model group. These results reveal that TGP suppresses juxta-articular osteoporosis and prevents subchondral bone loss. The decreased RANKL and increased OPG expression seen in TGP treated animals could explain how administration of TGP maintains higher BMD.

Disrupted bone remodeling leads to cochlear overgrowth and hearing loss in a mouse model of fibrous dysplasia.

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Omar Akil

Full Text Available Normal hearing requires exquisite cooperation between bony and sensorineural structures within the cochlea. For example, the inner ear secretes proteins such as osteoprotegrin (OPG that can prevent cochlear bone remodeling. Accordingly, diseases that affect bone regulation can also result in hearing loss. Patients with fibrous dysplasia develop trabecular bone overgrowth resulting in hearing loss if the lesions affect the temporal bones. Unfortunately, the mechanisms responsible for this hearing loss, which could be sensorineural and/or conductive, remain unclear. In this study, we used a unique transgenic mouse model of increased Gs G-protein coupled receptor (GPCR signaling induced by expression of an engineered receptor, Rs1, in osteoblastic cells. These ColI(2.3+/Rs1+ mice showed dramatic bone lesions that histologically and radiologically resembled fibrous dysplasia. We found that ColI(2.3+/Rs1+ mice showed progressive and severe conductive hearing loss. Ossicular chain impingement increased with the size and number of dysplastic lesions. While sensorineural structures were unaffected, ColI(2.3+/Rs1+ cochleae had abnormally high osteoclast activity, together with elevated tartrate resistant acid phosphatase (TRAP activity and receptor activator of nuclear factor kappa-B ligand (Rankl mRNA expression. ColI(2.3+/Rs1+ cochleae also showed decreased expression of Sclerostin (Sost, an antagonist of the Wnt signaling pathway that normally increases bone formation. The osteocyte canalicular networks of ColI(2.3+/Rs1+ cochleae were disrupted and showed abnormal osteocyte morphology. The osteocytes in the ColI(2.3+/Rs1+ cochleae showed increased expression of matrix metalloproteinase 13 (MMP-13 and TRAP, both of which can support osteocyte-mediated peri-lacunar remodeling. Thus, while the ossicular chain impingement is sufficient to account for the progressive hearing loss in fibrous dysplasia, the deregulation of bone remodeling extends to the

Retrospective analysis of survival rates and marginal bone loss on short implants in the mandible.

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Draenert, Florian G; Sagheb, Keyvan; Baumgardt, Katharina; Kämmerer, Peer W

2012-09-01

Short implants have become an interesting alternative to bone augmentation in dental implantology. Design of shorter implants and longer surveillance times are a current research issue. The goal of this study was to show the survival rates of short implants below 9 mm in the partly edentulous mandibular premolar and molar regions with fixed prosthetics. Marginal vertical and 2D bone loss was evaluated additionally. Different implant designs are orientationally evaluated. A total of 247 dental implants with fixed prosthetics (crowns and bridges) in the premolar and molar region of the mandible were evaluated; 47 implants were 9 mm or shorter. Patient data were evaluated to acquire implant survival rates, implant diameter, gender and age. Panoramic X-rays were analysed for marginal bone loss. Average surveillance time was 1327 days. Cumulative survival rate (CSR) of short implants was 98% (1 implants lost) compared to 94% in the longer implants group without significance. Thirty-five of the short implants were Astratech (0 losses) and 12 were Camlog Screw Line Promote Plus (1 loss). Early vertical and two-dimensional marginal bone loss was not significantly different in short and regular length implant group with an average of 0.6 mm and 0.7 mm(2) in short implants over the observation period. Within the limitations of this study, we conclude that short implants with a length of 9 mm or less have equal survival rates compared with longer implants over the observation period of 1-3 years. © 2011 John Wiley & Sons A/S.

Novel hybrid drilling protocol: evaluation for the implant healing--thermal changes, crestal bone loss, and bone-to-implant contact.

Science.gov (United States)

Calvo-Guirado, José Luis; Delgado-Peña, Jorge; Maté-Sánchez, Jose E; Mareque Bueno, Javier; Delgado-Ruiz, Rafael Arcesio; Romanos, Georgios E

2015-07-01

To evaluate a new hybrid drilling protocol, by the analysis of thermal changes in vitro, and their effects in the crestal bone loss and bone-to-implant contact in vivo. Temperature changes during simulated osteotomies with a hybrid drilling technique (biologic plus simplified) (test) versus an incremental drilling technique (control) were investigated. One hundred and twenty random osteotomies were performed (60 by group) in pig ribs up to 3.75-mm-diameter drill to a depth of 10 mm. Thermal changes and time were recorded by paired thermocouples. In a parallel experiment, bilateral mandibular premolars P2, P3, P4, and first molar M1 were extracted from six dogs. After 2-month healing, implant sites were randomly prepared using either of the drilling techniques. Forty eight implants of 3.75 mm diameter and 10 mm length were inserted. The dogs were euthanized at 30 and 90 days, and crestal bone loss (CBL) and bone-to-implant contact (BIC) were evaluated. The control group showed maximum temperatures of 35.3 °C ± 1.8 °C, ΔT of 10.4 °C, and a mean time of 100 s/procedure; meanwhile, the test group showed maximum temperatures of 36.7 °C ± 1.2 °C, ΔT of 8.1 °C, and a mean time of 240 s/procedure. After 30 days, CBL values for both groups (test: 1.168 ± 0.194 mm; control: 1.181 ± 0.113 mm) and BIC values (test: 43 ± 2.8%; control: 45 ± 1.3%) were similar, without significant differences (P > 0.05). After 90 days, CBL (test: 1.173 ± 0.187 mm; control: 1.205 ± 0.122 mm) and BIC (test: 64 ± 3.3%; control: 64 ± 2.4%) values were similar, without significant differences (P > 0.05). The BIC values were increased at 90 days in both groups compared with the 30-day period (P drilling procedure in vitro. Crestal bone loss and bone-to-implant contact in the hybrid drilling protocol are comparable with the conventional drilling protocol and do not affect the osseointegration process in vivo. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Radiographic bone loss in a Scottish non-smoking Type 1 Diabetes mellitus population; a Bitewing Radiographic Study.

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Plessas, Anastasios; Robertson, Douglas P; Hodge, Penny J

2018-05-15

The dental complications of uncontrolled diabetes include reduced salivary flow rate, candidiasis and periodontal manifestations. A recent meta-analysis concluded that diabetes patients have a significantly higher severity, but not extent, of destructive periodontal disease than non-diabetes people. The authors reported that most type-1 diabetes studies using dental radiographic data have not controlled for confounding factors such as smoking. The aim of this cross-sectional study was to compare radiographic alveolar bone loss between type 1 diabetes (T1DM) and non-diabetes (NDM) participants in a Scottish non-smoking population. Digital bitewing radiographs for 174 Scottish adult never or ex-smoker (> 5 years) participants (108 T1DM, 66 NDS), recruited from outpatient clinics throughout Greater Glasgow and Clyde, were included in the analysis. A single blinded, trained and calibrated examiner recorded the radiographic bone loss seen on bitewing radiographs using the digital screen caliper. The bone loss was measured as the distance between the cemento-enamel junction (CEJ) and the deepest radiographic alveolar bone margin interproximally of each tooth. T1DM participants had more radiographic alveolar bone loss throughout the all teeth measured (median:1.27 mm vs 1.06 mm, P diabetes subjects. Patients suffering from type 1 diabetes are at higher risk of periodontitis even when controlling for multiple possible confounding factors and this difference can be detected on routine dental radiographs at an early stage. These data confirm radiographically the previously reported association between T1DM and periodontal bone loss. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

Probiotic Lactobacillus rhamnosus GG prevents alveolar bone loss in a mouse model of experimental periodontitis.

Science.gov (United States)

Gatej, Simona M; Marino, Victor; Bright, Richard; Fitzsimmons, Tracy R; Gully, Neville; Zilm, Peter; Gibson, Rachel J; Edwards, Suzanne; Bartold, Peter M

2018-02-01

This study investigated the role of Lactobacillus rhamnosus GG (LGG) on bone loss and local and systemic inflammation in an in vivo mouse model of experimental periodontitis (PD). Experimental PD was induced in mice by oral inoculation with Porphyromonas gingivalis and Fusobacterium nucleatum over a period of 44 days. The probiotic LGG was administered via oral inoculation or oral gavage prior to, and during disease induction. The antimicrobial activity of LGG on the inoculum was also tested. Alveolar bone levels and gingival tissue changes were assessed using in vivo microcomputed tomography and histological analysis. Serum levels of mouse homologues for IL-8 were measured using multiplex assays. Pre-treatment with probiotics either via oral gavage or via oral inoculation significantly reduced bone loss (p loss in a mouse model of induced PD irrespective of the mode of administration. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

What causes bone loss?

Science.gov (United States)

... Paula FJA, Black DM, Rosen CJ. Osteoporosis and bone biology. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: ... HM. Bone development and remodeling. In: Jameson JL, De Groot ...

Smart Sensing System for Early Detection of Bone Loss: Current Status and Future Possibilities

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Nasrin Afsarimanesh

2018-02-01

Full Text Available Bone loss and osteoporosis is a serious health problem worldwide. The impact of osteoporosis is far greater than many other serious health problems, such as breast and prostate cancers. Statistically, one in three women and one in five men over 50 years of age will experience osteoporotic fractures in their life. In this paper, the design and development of a portable IoT-based sensing system for early detection of bone loss have been presented. The CTx-I biomarker was measured in serum samples as a marker of bone resorption. A planar interdigital sensor was used to evaluate the changes in impedance by any variation in the level of CTx-I. Artificial antibodies were used to introduce selectivity to the sensor for CTx-I molecule. Artificial antibodies for CTx-I molecules were created using molecular imprinted polymer (MIP technique in order to increase the stability of the system and reduce the production cost and complexity of the assay procedure. Real serum samples collected from sheep blood were tested and the result validation was done by using an ELISA kit. The PoC device was able to detect CTx-I concentration as low as 0.09 ng/mL. It exhibited an excellent linear behavior in the range of 0.1–2.5 ng/mL, which covers the normal reference ranges required for bone loss detection. Future possibilities to develop a smart toilet for simultaneous measurement of different bone turnover biomarkers was also discussed.

A novel role for dopamine signaling in the pathogenesis of bone loss from the atypical antipsychotic drug risperidone in female mice.

Science.gov (United States)

Motyl, Katherine J; Beauchemin, Megan; Barlow, Deborah; Le, Phuong T; Nagano, Kenichi; Treyball, Annika; Contractor, Anisha; Baron, Roland; Rosen, Clifford J; Houseknecht, Karen L

2017-10-01

Atypical antipsychotic (AA) drugs, including risperidone (RIS), are used to treat schizophrenia, bipolar disorder, and autism, and are prescribed off-label for other mental health issues. AA drugs are associated with severe metabolic side effects of obesity and type 2 diabetes. Cross-sectional and longitudinal data also show that risperidone causes bone loss and increases fracture risk in both men and women. There are several potential mechanisms of bone loss from RIS. One is hypogonadism due to hyperprolactinemia from dopamine receptor antagonism. However, many patients have normal prolactin levels; moreover we demonstrated that bone loss from RIS in mice can be blocked by inhibition of β-adrenergic receptor activation with propranolol, suggesting the sympathetic nervous system (SNS) plays a pathological role. Further, when, we treated ovariectomized (OVX) and sham operated mice daily for 8weeks with RIS or vehicle we demonstrated that RIS causes significant trabecular bone loss in both sham operated and OVX mice. RIS directly suppressed osteoblast number in both sham and OVX mice, but increased osteoclast number and surface in OVX mice alone, potentially accounting for the augmented bone loss. Thus, hypogonadism alone cannot explain RIS induced bone loss. In the current study, we show that dopamine and RIS are present in the bone marrow compartment and that RIS can exert its effects directly on bone cells via dopamine receptors. Our findings of both direct and indirect effects of AA drugs on bone are relevant for current and future clinical and translational studies investigating the mechanism of skeletal changes from AA drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

Retinaldehyde dehydrogenase 1 deficiency inhibits PPARγ-mediated bone loss and marrow adiposity.

Science.gov (United States)

Nallamshetty, Shriram; Le, Phuong T; Wang, Hong; Issacsohn, Maya J; Reeder, David J; Rhee, Eun-Jung; Kiefer, Florian W; Brown, Jonathan D; Rosen, Clifford J; Plutzky, Jorge

2014-10-01

PPARγ, a ligand-activated nuclear receptor, regulates fundamental aspects of bone homeostasis and skeletal remodeling. PPARγ-activating anti-diabetic thiazolidinediones in clinical use promote marrow adiposity, bone loss, and skeletal fractures. As such, delineating novel regulatory pathways that modulate the action of PPARγ, and its obligate heterodimeric partner RXR, may have important implications for our understanding and treatment of disorders of low bone mineral density. We present data here establishing retinaldehyde dehydrogenase 1 (Aldh1a1) and its substrate retinaldehyde (Rald) as novel determinants of PPARγ-RXR actions in the skeleton. When compared to wild type (WT) controls, retinaldehyde dehydrogenase-deficient (Aldh1a1(-/-)) mice were protected against bone loss and marrow adiposity induced by either the thiazolidinedione rosiglitazone or a high fat diet, both of which potently activate the PPARγ-RXR complex. Consistent with these results, Rald, which accumulates in vivo in Aldh1a1(-/-) mice, protects against rosiglitazone-mediated inhibition of osteoblastogenesis in vitro. In addition, Rald potently inhibits in vitro adipogenesis and osteoclastogenesis in WT mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) respectively. Primary Aldh1a1(-/-) HSCs also demonstrate impaired osteoclastogenesis in vitro compared to WT controls. Collectively, these findings identify Rald and retinoid metabolism through Aldh1a1 as important novel modulators of PPARγ-RXR transactivation in the marrow niche. Copyright © 2014 Elsevier Inc. All rights reserved.

Sheep model for osteoporosis: The effects of peripheral hormone therapy on centrally induced systemic bone loss in an osteoporotic sheep model.

Science.gov (United States)

Oheim, Ralf; Simon, Maciej J K; Steiner, Malte; Vettorazzi, Eik; Barvencik, Florian; Ignatius, Anita; Amling, Michael; Clarke, Iain J; Pogoda, Pia; Beil, F Timo

2017-04-01

Hypothalamic-pituitary disconnection (HPD) leads to low bone turnover followed by bone loss and reduced biomechanical properties in sheep. To investigate the role of peripheral hormones in this centrally induced systemic bone loss model, we planned a hormone replacement experiment. Therefore, estrogen (OHE), thyroxin (OHT) or a combination of both (OHTE) was substituted in ovariectomized HPD sheep, as both hormones are decreased in HPD sheep and are known to have a significant but yet not fully understood impact on bone metabolism. Bone turnover and structural parameters were analyzed in comparison to different control groups - untreated sheep (C), ovariectomized (O) and ovariectomized+HPD sheep (OH). We performed histomorphometric and HR-pQCT analyses nine months after the HPD procedure, as well as biomechanical testing of all ewes studied. In HPD sheep (OH) the low bone turnover led to a significant bone loss. Treatment with thyroxin alone (OHT) mainly increased bone resorption, leading to a further reduction in bone volume. In contrast, the treatment with estrogen alone (OHE) and the combined treatment with estrogen and thyroxin (OHTE) prevented HPD-induced bone loss completely. In conclusion, peripheral hormone substitution was able to prevent HPD-induced low-turnover osteoporosis in sheep. But only the treatment with estrogen alone or in combination with thyroxin was able to completely preserve bone mass and structure. These findings demonstrate the importance of peripheral hormones for a balanced bone remodeling and a physiological bone turnover. Copyright © 2017 Elsevier Ltd. All rights reserved.

Directed Research in Bone Discipline: Refining Previous Research Observations for Space Medicine

Science.gov (United States)

Sibonga, Jean D.

2015-01-01

Dual-energy X-ray absorptiometry bone mass density, as a sole index, is an insufficient surrogate for fracture; Clinical Practice Guidelines using bone mass density (both World Health Organization and FRAX) are not specific for complicated subjects such as young, healthy persons following prolonged exposure to skeletal unloading (i.e. an attribute of spaceflight); Research data suggest that spaceflight induces changes to astronaut bones that could be profound, possibly irreversible and unlike age-related bone loss on Earth.; There is a need to objectively assess factors across human physiology that are also influenced by spaceflight (e.g., muscle) that contribute to fracture risk. Some of these objective assessments may require innovative technologies, analyses and modeling.; Astronauts are also exposed to novel situations that may overload their bones highlighting a need integrate biomechanics of physical activities into risk assessments.; As we accumulate data, which reflects the biomechanical competence of bone under specific mechanically-loaded scenarios (even activities of daily living), BONE expects Bone Fracture Module to be more sensitive and/or have less uncertainty in its assessments of fracture probability.; Fracture probability drives the requirement for countermeasures. Level of evidence will unlikely be obtained; hence, the Bone Research and Clinical Advisory Panel (like a Data Safety Monitoring Board) will provide the recommendations.

Evaluation of the efficacy of zoledronic acid and amifostine on radiation induced bone loss in mice

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Kim, Jin Wook; Lee, Sueum; Kang, Sohi; Moon, Cahng Jong; Kim, Jong Choon; Kim, Sung Ho [College of Veterinary Medicine, Chonnam National University, Gwangju (Korea, Republic of); Jung, Uhee; Jo, Sung Kee [Advanced Radiation Technology Institute, Jeungeup (Korea, Republic of); Jang, Jong Sik [College of Ecology and Environmental Science, Kyungpook National University, Sangju (Korea, Republic of)

2016-09-15

This study investigated the effects of zoledronic acid (ZA) on radiation-induced bone loss in C3H/HeN mice. C3H/HeN mice were divided into sham control and three irradiated groups (3 Gy, gamma ray). The irradiated mice were treated for 12 weeks with vehicle, amifostine (intraperitoneal injection), or ZA (subcutaneous injection). Grip strength, uterus weight, and serum alkaline phosphatase (ALP), and tartrate-resistant acid phosphatase (TRAP) levels were measured. Tibiae were analyzed using micro-computed tomography. Treatment of ZA (100 μg·kg{sup -1}·week{sup -1}) significantly preserved trabecular bone volume, trabecular thickness, trabecular number, trabecular separation, bone mineral density of proximal tibia metaphysic, and cortical bone volume, but did not alter the uterus weight of the mice. The administration of ZA for 12 weeks lowered serum ALP and TRAP levels in irradiated mice, suggesting that ZA can reduce the bone turnover rate in mice. No differences were apparent between the amifostine-treated group and the irradiation control group. The results indicate that ZA can prevent radiation-induced bone loss in mice.

Phyto-oestrogen excretion and rate of bone loss in postmenopausal women

NARCIS (Netherlands)

Kardinaal, A.F.M.; Morton, M.S.; Brüggemann-Rotgans, I.E.M.; Beresteijn, E.C.H. van

1998-01-01

Objective: The hypothesis was tested that the rate of postmenopausal bone loss is inversely associated with long-term urinary excretion of phyto-oestrogens, as a marker of habitual dietary intake. Design: Secondary analysis of a 10-year follow-up study (1979-1989) among postmenopausal women in the

Absence of ERRalpha in female mice confers resistance to bone loss induced by age or estrogen-deficiency.

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Catherine Teyssier

Full Text Available BACKGROUND: ERRalpha is an orphan member of the nuclear hormone receptor superfamily, which acts as a transcription factor and is involved in various metabolic processes. ERRalpha is also highly expressed in ossification zones during mouse development as well as in human bones and cell lines. Previous data have shown that this receptor up-modulates the expression of osteopontin, which acts as an inhibitor of bone mineralization and whose absence results in resistance to ovariectomy-induced bone loss. Altogether this suggests that ERRalpha may negatively regulate bone mass and could impact on bone fragility that occurs in the absence of estrogens. METHODS/PRINCIPAL FINDINGS: In this report, we have determined the in vivo effect of ERRalpha on bone, using knock-out mice. Relative to wild type animals, female ERRalphaKO bones do not age and are resistant to bone loss induced by estrogen-withdrawal. Strikingly male ERRalphaKO mice are indistinguishable from their wild type counterparts, both at the unchallenged or gonadectomized state. Using primary cell cultures originating from ERRalphaKO bone marrow, we also show that ERRalpha acts as an inhibitor of osteoblast differentiation. CONCLUSION/SIGNIFICANCE: Down-regulating ERRalpha could thus be beneficial against osteoporosis.

Does the Laser-Microtextured Short Implant Collar Design Reduce Marginal Bone Loss in Comparison with a Machined Collar?

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B. Alper Gultekin

2016-01-01

Full Text Available Purpose. To compare marginal bone loss between subgingivally placed short-collar implants with machined collars and those with machined and laser-microtextured collars. Materials and Methods. The investigators used a retrospective study design and included patients who needed missing posterior teeth replaced with implants. Short-collar implants with identical geometries were divided into two groups: an M group, machined collar; and an L group, machined and laser-microtextured collar. Implants were evaluated according to marginal bone loss, implant success, and probing depth (PD at 3 years of follow-up. Results. Sixty-two patients received 103 implants (56 in the M group and 47 in the L group. The cumulative survival rate was 100%. All implants showed clinically acceptable marginal bone loss, although bone resorption was lower in the L group (0.49 mm than in the M group (1.38 mm at 3 years (p<0.01. A significantly shallower PD was found for the implants in the L group during follow-up (p<0.01. Conclusions. Our results suggest predictable outcomes with regard to bone loss for both groups; however, bone resorption was less in the L group than in the M group before and after loading. The laser-microtextured collar implant may provide a shallower PD than the machined collar implant.

Vascularized fibular graft in infected tibial bone loss

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C Cheriyan Kovoor

2011-01-01

Full Text Available Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm. The mean length of the graft was 16.7 cm (range 11.5 - 21 cm. The osteoseptocutaneous flap (bone flap with attached overlying skin flap from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months. The Pearson correlation coefficient (r was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft

Comparison of Marginal Bone Loss Between Implants with Internal and External Connections: A Systematic Review.

Science.gov (United States)

Palacios-Garzón, Natalia; Mauri-Obradors, Elisabeth; Roselló-LLabrés, Xavier; Estrugo-Devesa, Albert; Jané-Salas, Enric; López-López, José

The objective of this systematic review was to compare the loss of marginal bone between implants with internal and external connections by analyzing results reported in studies published after 2010. A literature search in MEDLINE with the keywords "dental implant connections, external internal implant connection, bone loss implant designs, internal and external connection implant studies in humans" was conducted. Clinical trials on human beings, comparing both connections and published in English, from 2010 to 2016 were selected. Their methodologic quality was assessed using the Jadad scale. From the initial search, 415 articles were obtained; 32 were chosen as potentially relevant based on their titles and abstracts. Among them, only 10 finally met the inclusion criteria. A total of 1,523 patients with 3,965 implants were analyzed. Six out of 10 studies observed that internal connections showed significantly less bone loss compared with external connections. The remaining four articles did not find statistically significant differences between the two connections. According to this systematic review and considering its limitation due to the degree of heterogeneity between the included studies, both internal and external connections present high survival rates. To assess whether marginal bone loss differs significantly between the two connections, more homogenous clinical studies are needed with identical implant characteristics, larger samples, and longer follow-up periods. Studies included in this review and characterized by long-term follow-ups showed that the external connection is a reliable connection on a long-term basis.

Increased periodontal bone loss in temporarily B lymphocyte-deficient rats

DEFF Research Database (Denmark)

Klausen, B; Hougen, H P; Fiehn, N E

1989-01-01

In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific-pathogen-free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte-deficient), thymus-grafted nude (T-lym......-lymphocyte deficiency did not interfere with the development of periodontal disease in this model, whereas a temporary and moderate reduction in B-lymphocyte numbers seemed to predispose for aggravation of periodontal bone loss.......In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific-pathogen-free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte-deficient), thymus-grafted nude (T...... had significantly less periodontal bone support than controls. Anti-mu treated inoculated rats had significantly less periodontal bone support than nude and normal rats, whereas no difference was found between normal, nude, and thymus-grafted rats. It is concluded that permanent T...

Hypercortisolemia Is Associated with Severity of Bone Loss and Depression in Hypothalamic Amenorrhea and Anorexia Nervosa

OpenAIRE

Lawson, Elizabeth A.; Donoho, Daniel; Miller, Karen K.; Misra, Madhusmita; Meenaghan, Erinne; Lydecker, Janet; Wexler, Tamara; Herzog, David B.; Klibanski, Anne

2009-01-01

Context: Anorexia nervosa (AN) and functional hypothalamic amenorrhea (HA) are associated with low bone density, anxiety, and depression. Women with AN and HA have elevated cortisol levels. Significant hypercortisolemia, as in Cushing’s disease, causes bone loss. It is unknown whether anxiety and depression and/or cortisol dysregulation contribute to low bone density in AN or HA.

Increased activity of osteocyte autophagy in ovariectomized rats and its correlation with oxidative stress status and bone loss

Energy Technology Data Exchange (ETDEWEB)

Yang, Yuehua, E-mail: yuesjtu@126.com; Zheng, Xinfeng, E-mail: zxf272@126.com; Li, Bo, E-mail: libo@126.com; Jiang, Shengdan, E-mail: jiangsd@126.com; Jiang, Leisheng, E-mail: leisheng_jiang@126.com

2014-08-15

Highlights: • Examine autophagy level in the proximal tibia of ovariectomized rats. • Investigate whether autophagy level is associated with bone loss. • Investigate whether autophagy level is associated with oxidative stress status. - Abstract: Objectives: The objectives of the present study were to investigate ovariectomy on autophagy level in the bone and to examine whether autophagy level is associated with bone loss and oxidative stress status. Methods: 36 female Sprague–Dawley rats were randomly divided into sham-operated (Sham), and ovariectomized (OVX) rats treated either with vehicle or 17-β-estradiol. At the end of the six-week treatment, bone mineral density (BMD) and bone micro-architecture in proximal tibias were assessed by micro-CT. Serum 17β-estradiol (E2) level were measured. Total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity in proximal tibia was also determined. The osteocyte autophagy in proximal tibias was detected respectively by Transmission Electron Microscopy (TEM), immunofluorescent histochemistry (IH), realtime-PCR and Western blot. In addition, the spearman correlation between bone mass, oxidative stress status, serum E2 and autophagy were analyzed. Results: Ovariectomy increased Atg5, LC3, and Beclin1 mRNA and proteins expressions while decreased p62 expression. Ovariectomy also declined the activities of T-AOC, CAT, and SOD. Treatment with E2 prevented the reduction in bone mass as well as restored the autophagy level. Furthermore, LC3-II expression was inversely correlated with T-AOC, CAT, and SOD activities. A significant inverse correlation between LC3-II expression and BV/TV, Tb.N, BMD in proximal tibias was found. Conclusions: Ovariectomy induced oxidative stress, autophagy and bone loss. Autophagy of osteocyte was inversely correlated with oxidative stress status and bone loss.

Frequent complications and severe bone loss associated with the repiphysis expandable distal femoral prosthesis.

Science.gov (United States)

Cipriano, Cara A; Gruzinova, Irina S; Frank, Rachel M; Gitelis, Steven; Virkus, Walter W

2015-03-01

The treatment of choice for distal femur malignancies in skeletally immature patients remains controversial. An expandable endoprosthesis device (Repiphysis Limb Salvage System; Wright Medical Technology, Arlington, TN, USA) allows for limb preservation and noninvasive lengthening but has been associated with significant complications; however, the extent and implications of bone loss associated with this implant have not been reported. Our goals were to report (1) the 2-year minimum clinical outcomes after placement of the Repiphysis expandable prosthesis for pediatric distal femur malignancies; (2) the complications associated with this prosthesis; (3) the failure rate of this prosthesis; and (4) the revision alternatives available for salvage procedures. Between 2002 and 2010, one surgeon (SG) treated all skeletally immature patients (mean age, 10.1 years; range, 4.7-13.6 years) with distal femoral osteosarcoma using a Repiphysis expandable prosthesis. Of the 12 patients who met these criteria, two were excluded for death from disease before 2 years, and mean followup for the remaining 10 was 72 months (range, 26-119 months). Medical records were retrospectively reviewed for complications and clinical outcomes, as assessed by the Musculoskeletal Tumor Society (MSTS) scoring system. Radiographs at final followup were reviewed for bone loss and analyzed by the two senior authors (SG, WWV) to determine reconstruction options available for future revisions. MSTS scores averaged 67%, and we observed 37 implant-related complications requiring a total of 15 reoperations. Six patients underwent implant revisions with aseptic loosening being the predominant mode of failure; ultimately, four of these were converted to adult modular oncology prostheses, and two underwent total femoral replacements. Bone loss in this series was severe in terms of femoral length, cortical thinning, and metadiaphyseal compromise, and most patients will not have sufficient bone stock to permit

Immunization with FSHβ fusion protein antigen prevents bone loss in a rat ovariectomy-induced osteoporosis model

Energy Technology Data Exchange (ETDEWEB)

Geng, Wenxin; Yan, Xingrong; Du, Huicong; Cui, Jihong; Li, Liwen, E-mail: liven@nwu.edu.cn; Chen, Fulin, E-mail: chenfl@nwu.edu.cn

2013-05-03

Highlights: •A GST-FSH fusion protein was successfully expressed in E. coli. •Immunization with GST-FSH antigen can raise high-titer anti-FSH polyclonal sera. •Anti-FSH polyclonal sera can neutralize osteoclastogenic effect of FSH in vitro. •FSH immunization can prevent bone loss in a rat osteoporosis model. -- Abstract: Osteoporosis, a metabolic bone disease, threatens postmenopausal women globally. Hormone replacement therapy (HTR), especially estrogen replacement therapy (ERT), is used widely in the clinic because it has been generally accepted that postmenopausal osteoporosis is caused by estrogen deficiency. However, hypogonadal α and β estrogen receptor null mice were only mildly osteopenic, and mice with either receptor deleted had normal bone mass, indicating that estrogen may not be the only mediator that induces osteoporosis. Recently, follicle-stimulating hormone (FSH), the serum concentration of which increases from the very beginning of menopause, has been found to play a key role in postmenopausal osteoporosis by promoting osteoclastogenesis. In this article, we confirmed that exogenous FSH can enhance osteoclast differentiation in vitro and that this effect can be neutralized by either an anti-FSH monoclonal antibody or anti-FSH polyclonal sera raised by immunizing animals with a recombinant GST-FSHβ fusion protein antigen. Moreover, immunizing ovariectomized rats with the GST-FSHβ antigen does significantly prevent trabecular bone loss and thereby enhance the bone strength, indicating that a FSH-based vaccine may be a promising therapeutic strategy to slow down bone loss in postmenopausal women.

Bisphosphonates Inhibit Pain, Bone Loss, and Inflammation in a Rat Tibia Fracture Model of Complex Regional Pain Syndrome.

Science.gov (United States)

Wang, Liping; Guo, Tian-Zhi; Hou, Saiyun; Wei, Tzuping; Li, Wen-Wu; Shi, Xiaoyou; Clark, J David; Kingery, Wade S

2016-10-01

Bisphosphonates are used to prevent the bone loss and fractures associated with osteoporosis, bone metastases, multiple myeloma, and osteogenesis deformans. Distal limb fractures cause regional bone loss with cutaneous inflammation and pain in the injured limb that can develop into complex regional pain syndrome (CRPS). Clinical trials have reported that antiresorptive bisphosphonates can prevent fracture-induced bone loss, inhibit serum inflammatory cytokine levels, and alleviate CRPS pain. Previously, we observed that the inhibition of inflammatory cytokines or adaptive immune responses attenuated the development of pain behavior in a rat fracture model of CRPS, and we hypothesized that bisphosphonates could prevent pain behavior, trabecular bone loss, postfracture cutaneous cytokine upregulation, and adaptive immune responses in this CRPS model. Rats underwent tibia fracture and cast immobilization for 4 weeks and were chronically administered either subcutaneously perfused alendronate or oral zoledronate. Behavioral measurements included hindpaw von Frey allodynia, unweighting, warmth, and edema. Bone microarchitecture was measured by microcomputed tomography, and bone cellular activity was evaluated by static and dynamic histomorphometry. Spinal cord Fos immunostaining was performed, and skin cytokine (tumor necrosis factor, interleukin [IL]-1, IL-6) and nerve growth factor (NGF) levels were determined by enzyme immunoassay. Skin and sciatic nerve immunoglobulin levels were determined by enzyme immunoassay. Rats with tibia fractures developed hindpaw allodynia, unweighting, warmth, and edema, increased spinal Fos expression and trabecular bone loss in the lumbar vertebra and bilateral distal femurs as measured by microcomputed tomography, increased trabecular bone resorption and osteoclast surface with decreased bone formation rates, increased cutaneous inflammatory cytokine and NGF expression, and elevated immunocomplex deposition in skin and nerve

Bone mineral content and bone metabolism in young adults with severe periodontitis

DEFF Research Database (Denmark)

Wowern von, N.; Westergaard, J.; Kollerup, G.

2001-01-01

Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

Immediate Initiation of Antiretroviral Therapy for HIV Infection Accelerates Bone Loss Relative to Deferring Therapy

DEFF Research Database (Denmark)

Hoy, Jennifer F; Grund, Birgit; Roediger, Mollie P

2017-01-01

Both HIV infection and antiretroviral therapy (ART) are associated with lower bone mineral density (BMD) and increased fracture risk. Because the relative contributions of ART and untreated HIV to BMD loss are unclear, it is important to quantify the effect of ART on bone. We compared the effect ...

Ecological optimization of an irreversible quantum Carnot heat engine with spin-1/2 systems

International Nuclear Information System (INIS)

Liu Xiaowei; Chen Lingen; Wu Feng; Sun Fengrui

2010-01-01

A model of a quantum heat engine with heat resistance, internal irreversibility and heat leakage and many non-interacting spin-1/2 systems is established in this paper. The quantum heat engine cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot heat engine. Based on the quantum master equation and the semi-group approach, equations of some important performance parameters, such as power output, efficiency, entropy generation rate and ecological function (a criterion representing the optimal compromise between exergy output rate and exergy loss rate), for the irreversible spin quantum Carnot heat engine are derived. The optimal ecological performance of the heat engine in the classical limit is analyzed with numerical examples. The effects of internal irreversibility and heat leakage on ecological performance are discussed in detail.

Pyogenic granuloma associated with periodontal abscess and bone loss - A rare case report

Directory of Open Access Journals (Sweden)

Bhrugesh J Panseriya

2011-01-01

Full Text Available A diverse group of the pathologic process can produce the enlargement of soft tissues in the oral cavity and often present a diagnostic challenge. This soft tissue enlargement may represent a variation of the normal anatomic structure, inflammatory reaction, cyst, neoplasm, and developmental anomalies. A group of reactive hyperplasias, which develop in response to chronic recurring tissue injury that stimulates an excessive tissue repair response. The pyogenic granuloma (PG is a reactive enlargement that is an inflammatory response to local irritation such as calculus, a fractured tooth, rough dental restoration, and foreign materials or hormonal (pregnancy tumor and rarely associated with bone loss. This paper presents a rare case of PG associated with periodontal abscess and bone loss in a 30-year-old male.

Pyogenic granuloma associated with periodontal abscess and bone loss - A rare case report.

Science.gov (United States)

Panseriya, Bhrugesh J; Hungund, Shital

2011-07-01

A diverse group of the pathologic process can produce the enlargement of soft tissues in the oral cavity and often present a diagnostic challenge. This soft tissue enlargement may represent a variation of the normal anatomic structure, inflammatory reaction, cyst, neoplasm, and developmental anomalies. A group of reactive hyperplasias, which develop in response to chronic recurring tissue injury that stimulates an excessive tissue repair response. The pyogenic granuloma (PG) is a reactive enlargement that is an inflammatory response to local irritation such as calculus, a fractured tooth, rough dental restoration, and foreign materials or hormonal (pregnancy tumor) and rarely associated with bone loss. This paper presents a rare case of PG associated with periodontal abscess and bone loss in a 30-year-old male.

BMI-1 Mediates Estrogen-Deficiency-Induced Bone Loss by Inhibiting Reactive Oxygen Species Accumulation and T Cell Activation.

Science.gov (United States)

Li, Jinbo; Wang, Qian; Yang, Renlei; Zhang, Jiaqi; Li, Xing; Zhou, Xichao; Miao, Dengshun

2017-05-01

Previous studies have shown that estrogen regulates bone homeostasis through regulatory effects on oxidative stress. However, it is unclear how estrogen deficiency triggers reactive oxygen species (ROS) accumulation. Recent studies provide evidence that the B lymphoma Mo-MLV insertion region 1 (BMI-1) plays a critical role in protection against oxidative stress and that this gene is directly regulated by estrogen via estrogen receptor (ER) at the transcriptional level. In this study, ovariectomized mice were given drinking water with/without antioxidant N-acetyl-cysteine (NAC, 1 mg/mL) supplementation, and compared with each other and with sham mice. Results showed that ovariectomy resulted in bone loss with increased osteoclast surface, increased ROS levels, T cell activation, and increased TNF and RANKL levels in serum and in CD4 T cells; NAC supplementation largely prevented these alterations. BMI-1 expression levels were dramatically downregulated in CD4 T cells from ovariectomized mice. We supplemented drinking water to BMI-1-deficient mice with/without NAC and compared them with each other and with wild-type (WT) mice. We found that BMI-1 deficiency mimicked alterations observed in ovariectomy whereas NAC supplementation reversed all alterations induced by BMI-1 deficiency. Because T cells are critical in mediating ovariectomy-induced bone loss, we further assessed whether BMI-1 overexpression in lymphocytes can protect against estrogen deficiency-induced osteoclastogenesis and bone loss by inhibiting oxidative stress, T cell activation, and RANKL production. When WT and Eμ-BMI-1 transgenic mice with BMI-1 specifically overexpressed in lymphocytes were ovariectomized and compared with each other and with WT sham mice, we found that BMI-1 overexpression in lymphocytes clearly reversed all alterations induced by ovariectomy. Results from this study indicate that estrogen deficiency downregulates BMI-1 and subsequently increases ROS, T cell activation, and

The influence of implant-abutment connection to peri-implant bone loss: A systematic review and meta-analysis.

Science.gov (United States)

Caricasulo, Riccardo; Malchiodi, Luciano; Ghensi, Paolo; Fantozzi, Giuliano; Cucchi, Alessandro

2018-05-15

Different implant-abutment connections are available and it has been claimed they could have an effect on marginal bone loss. The aim of this review is to establish if implant connection configuration influences peri-implant bone loss (PBL) after functional loading. A specific question was formulated according to the Population, Intervention, Control, and Outcome (PICO): Does the type of implant-abutment connection (external, internal, or conical) have an influence on peri-implant bone loss? A PubMed/MEDLINE electronic search was conducted to identify English language publications published in international journals during the last decade (from 2006 to 2016). The search was conducted by using the Medical Subject Headings (MeSH) keywords "dental implants OR dental abutment AND external connection OR internal connection OR conical connection OR Morse Taper." Selected studies were randomized clinical trials and prospective studies; in vitro studies, case reports and retrospective studies were excluded. Titles and abstracts and, in the second phase, full texts, were evaluated autonomously and in duplicate by two reviewers. A total of 1649 articles were found, but only 14 studies met the pre-established inclusion criteria and were considered suitable for meta-analytic analysis. The network meta-analysis (NMA) suggested a significant difference between the external and the conical connections; this was less evident for the internal and conical ones. Platform-switching (PS) seemed to positively affect bone levels, non-regarding the implant-connection it was applied to. Within the limitations of this systematic review, it can be concluded that crestal bone levels are better maintained in the short-medium term when internal kinds of interface are adopted. In particular, conical connections seem to be more advantageous, showing lower peri-implant bone loss, but further studies are necessary to investigate the efficacy of implant-abutment connection on stability of crestal

Antibody-based inhibition of circulating DLK1 protects from estrogen deficiency-induced bone loss in mice

DEFF Research Database (Denmark)

Figeac, Florence; Andersen, Ditte C.; Nipper Nielsen, Casper A.

2018-01-01

/TV) and inhibition of bone resorption. No significant changes were observed in total fat mass or in the number of bone marrow adipocytes. These results support the potential use of anti-DLK1 antibody therapy as a novel intervention to protect from E deficiency associated bone loss....... resorption and inhibition of bone formation. Further, serum DLK1 levels are elevated and positively correlated to bone turnover markers in estrogen (E)-deficient rodents and women. In this report, we examined whether inhibition of serum DLK1 activity using a neutralizing monoclonal antibody protects from E...

Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance

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Maira L. Mendonça

Full Text Available OBJECTIVES: Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated. METHODS: This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT and 21 controls (CG. Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels. RESULTS: A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01. Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%. The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005, but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass. CONCLUSION: These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

Peri-Implant Crestal Bone Loss: A Putative Mechanism

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Yuko Ujiie

2012-01-01

Full Text Available Purpose. The immunological mechanisms of peri-implant crestal bone loss have, hitherto, not been elucidated. We hypothesized that bacterial products from the microgap cause upregulation of cytokines in otherwise healthy peri-implant cells, which results in osteoclast formation and, ultimately, in bone resorption. Materials and Methods. We used RT-PCR and ELISA to assay mediators of osteoclastogenesis in rat and human macrophages (r-and hMO; bone marrow derived stromal cells (r-and hBMCs; and human gingival fibroblasts (hGF—with or without stimulation by LPS. TRAP positive multinucleate cells were assessed for their resorptive ability. Results. We show that IL-1α, IL-1β, and IL-6 were expressed by all examined cell types, and TNF-α was upregulated in hGF. Secretion of IL-1α and IL-1β proteins was stimulated in hMO by LPS, and IL-6 protein secretion was highly stimulated in hBMCs and hGF. Both LPS and RANKL stimulated macrophages to form osteoclast-like TRAP positive cells, which resorbed calcium phosphate substrates. Conclusion. Taken together, the results of our study support the hypothesis that bacterial endotoxins upregulate enhanced mediators of osteoclastogenesis in resident cells found in the healthy peri-implant compartment and that the local synergistic action of cytokines secreted by such cells results in the genesis of resorptively active osteoclasts.

Detailed Modeling and Irreversible Transfer Process Analysis of a Multi-Element Thermoelectric Generator System

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Xiao, Heng; Gou, Xiaolong; Yang, Suwen

2011-05-01

Thermoelectric (TE) power generation technology, due to its several advantages, is becoming a noteworthy research direction. Many researchers conduct their performance analysis and optimization of TE devices and related applications based on the generalized thermoelectric energy balance equations. These generalized TE equations involve the internal irreversibility of Joule heating inside the thermoelectric device and heat leakage through the thermoelectric couple leg. However, it is assumed that the thermoelectric generator (TEG) is thermally isolated from the surroundings except for the heat flows at the cold and hot junctions. Since the thermoelectric generator is a multi-element device in practice, being composed of many fundamental TE couple legs, the effect of heat transfer between the TE couple leg and the ambient environment is not negligible. In this paper, based on basic theories of thermoelectric power generation and thermal science, detailed modeling of a thermoelectric generator taking account of the phenomenon of energy loss from the TE couple leg is reported. The revised generalized thermoelectric energy balance equations considering the effect of heat transfer between the TE couple leg and the ambient environment have been derived. Furthermore, characteristics of a multi-element thermoelectric generator with irreversibility have been investigated on the basis of the new derived TE equations. In the present investigation, second-law-based thermodynamic analysis (exergy analysis) has been applied to the irreversible heat transfer process in particular. It is found that the existence of the irreversible heat convection process causes a large loss of heat exergy in the TEG system, and using thermoelectric generators for low-grade waste heat recovery has promising potential. The results of irreversibility analysis, especially irreversible effects on generator system performance, based on the system model established in detail have guiding significance for

Prophylactic pamidronate partially protects from glucocorticoid-induced bone loss in the mdx mouse model of Duchenne muscular dystrophy.

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Yoon, Sung-Hee; Chen, Jinghan; Grynpas, Marc D; Mitchell, Jane

2016-09-01

Glucocorticoids are extensively used to treat patients with Duchenne muscular dystrophy because of their ability to delay muscle damage, prolong ambulation and extend life. However, use of glucocorticoids significantly increases bone loss, fragility and fractures. To determine if antiresorptive bisphosphonates could prevent the effects of glucocorticoids on bone quality, we used dystrophic mdx mice treated with the glucocorticoid prednisone during 8weeks of rapid bone growth from 5 to 13weeks of age and treated some mice with the bisphosphonate pamidronate during the first two weeks of prednisone administration. Prednisone reduced long bone growth, decreased cortical bone thickness and area and decreased the strength of the femurs. Pamidronate treatment protected mice from cortical bone loss but did not increase bone strength. The combination of prednisone and pamidronate inhibited remodeling of metaphyseal trabecular bone with large numbers of trabeculae containing remnants of calcified cartilage. Prednisone improved muscle strength in the mdx mice and decreased serum creatine kinase with evidence of improved muscle histology and these effects were maintained in mice treated with pamidronate. Copyright © 2016. Published by Elsevier Inc.

Recurrent anterior shoulder instability: accuracy of estimations of glenoid bone loss with computed tomography is insufficient for therapeutic decision-making

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Huijsmans, Polydoor Emile [Haga Hospital, Department of Orthopedic Surgery, The Hague (Netherlands); Witte, Pieter Bas de [Leiden University Medical Center, Department of Orthopedic Surgery, Leiden (Netherlands); Villiers, Richard V.P. de; Kruger, Niel Ruben [Van Wageningen and Partners, Radiology Department, Somerset West (South Africa); Wolterbeek, Derk Willem; Warmerdam, Piet [Haga Hospital, Department of Radiology, The Hague (Netherlands); Beer, Joe F. de [Cape Shoulder Institute, Department of Orthopedic Surgery, Cape Town (South Africa)

2011-10-15

To evaluate the reliability of glenoid bone loss estimations based on either axial computed tomography (CT) series or single sagittal (''en face'' to glenoid) CT reconstructions, and to assess their accuracy by comparing with actual CT-based bone loss measurements, in patients with anterior glenohumeral instability. In two separate series of patients diagnosed with recurrent anterior glenohumeral instability, glenoid bone loss was estimated on axial CT series and on the most lateral sagittal (en face) glenoid view by two blinded radiologists. Additionally, in the second series of patients, glenoid defects were measured on sagittal CT reconstructions by an independent observer. In both series, larger defects were estimated when based on sagittal CT images compared to axial views. In the second series, mean measured bone loss was 11.5% (SD = 6.0) of the total original glenoid area, with estimations of 9.6% (SD = 7.2) and 7.8% (SD = 4.2) for sagittal and axial views, respectively. Correlations of defect estimations with actual measurements were fair to poor; glenoid defects tended to be underestimated, especially when based on axial views. CT-based estimations of glenoid bone defects are inaccurate. Especially for axial views, there is a high chance of glenoid defect underestimation. When using glenoid bone loss quantification in therapeutic decision-making, measuring the defect instead of estimating is strongly advised. (orig.)

Men and Women in Space: Bone Loss and Kidney Stone Risk after Long-Duration Space Flight

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Smith, Scott M.; Zwart, Sara R.; Heer, Martina; Hudson, Edgar, K.; Shackelford, Linda; Morgan, Jennifer L. L.

2014-01-01

Bone loss on Earth is more prevalent in women than men, leading to the assumption that women may be at greater risk from bone loss during flight. Until recently, the number of women having flown long-duration missions was too small to allow any type of statistical analysis. We report here data from 42 astronauts on long-duration missions to the International Space Station, 33 men and 9 women. Bone mineral density (dual-energy X-ray absorptiometry), bone biochemistry (from blood and urine samples), and renal stone risk factors were evaluated before and after flight. Data were analyzed in two groups, based on available resistance exercise equipment. The response of bone mineral density to flight was the same for men and women, and the typical decrease in bone mineral density (whole body and/or regional) after flight was not observed for either sex for those using an Advanced Resistive Exercise Device. Bone biochemistry, specifically markers of formation and resorption, generally responded similarly in male and female astronauts. The response of urinary supersaturation risk to space flight was not significantly different between men and women, although risks were typically increased after flight in both groups and risks were generally greater in men than in women before and after flight. Overall, the bone and renal stone responses of men and women to space flight were not different.

A reversal phase arrest uncoupling the bone formation and resorption contributes to the bone loss in glucocorticoid treated ovariectomised aged sheep

DEFF Research Database (Denmark)

Andreasen, Christina Møller; Ding, Ming; Overgaard, Søren

2015-01-01

Large animals as sheep are often used as models for human osteoporosis. Our aim was therefore to determine how glucocorticoid treatment of ovariectomised sheep affects the cancellous bone, determining the cellular events within the bone remodelling process that contributes to their bone loss...... in postmenopausal women with glucocorticoid-induced osteoporosis. This supports the relevance of the sheep model to the pathophysiology of glucocorticoid-induced osteoporosis in postmenopausal women, making it a relevant preclinical model for orthopaedic implant and biomaterial research........ Twenty female sheep were assigned for two groups; an untreated control group and an ovariectomised group treated with glucocorticoids (0.6mg/kg/day, 5 times weekly) for 7months. At 7months the glucocorticoid-treated ovariectomised sheep showed a significant change in the bone microstructure revealed...

Changes in bone marrow lesions in response to weight-loss in obese knee osteoarthritis patients

DEFF Research Database (Denmark)

Gudbergsen, Henrik; Boesen, Mikael; Christensen, Robin

2013-01-01

Patients are susceptible for knee osteoarthritis (KOA) with increasing age and obesity and KOA is expected to become a major disabling disease in the future. An important feature of KOA on magnetic resonance imaging (MRI) is changes in the subchondral bone, bone marrow lesions (BMLs), which...... are related to the future degeneration of the knee joint as well as prevalent clinical symptoms. The aim of this study was to investigate the changes in BMLs after a 16-week weight-loss period in obese subjects with KOA and relate changes in BMLs to the effects of weight-loss on clinical symptoms....

Hypercortisolemia is associated with severity of bone loss and depression in hypothalamic amenorrhea and anorexia nervosa.

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Lawson, Elizabeth A; Donoho, Daniel; Miller, Karen K; Misra, Madhusmita; Meenaghan, Erinne; Lydecker, Janet; Wexler, Tamara; Herzog, David B; Klibanski, Anne

2009-12-01

Anorexia nervosa (AN) and functional hypothalamic amenorrhea (HA) are associated with low bone density, anxiety, and depression. Women with AN and HA have elevated cortisol levels. Significant hypercortisolemia, as in Cushing's disease, causes bone loss. It is unknown whether anxiety and depression and/or cortisol dysregulation contribute to low bone density in AN or HA. Our objective was to investigate whether hypercortisolemia is associated with bone loss and mood disturbance in women with HA and AN. We conducted a cross-sectional study in a clinical research center. We studied 52 women [21 healthy controls (HC), 13 normal-weight women with functional HA, and 18 amenorrheic women with AN]. Serum samples were measured every 20 min for 12 h overnight and pooled for average cortisol levels. Bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry (DXA) at anteroposterior and lateral spine and hip. Hamilton Rating Scales for Anxiety (HAM-A) and Depression (HAM-D) were administered. BMD was lower in AN and HA than HC at all sites and lower in AN than HA at the spine. On the HAM-D and HAM-A, AN scored higher than HA, and HA scored higher than HC. Cortisol levels were highest in AN, intermediate in HA, and lowest in HC. HAM-A and HAM-D scores were associated with decreased BMD. Cortisol levels were positively associated with HAM-A and HAM-D scores and negatively associated with BMD. Hypercortisolemia is a potential mediator of bone loss and mood disturbance in these disorders.

Impact of marked weight loss induced by bariatric surgery on bone mineral density and remodeling

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F.A. Pereira

2007-04-01

Full Text Available Data about the impact of bariatric surgery (BS and subsequent weight loss on bone are limited. The objective of the present study was to determine bone mineral density (BMD, bone remodeling metabolites and hormones that influence bone trophism in premenopausal women submitted to BS 9.8 months, on average, before the study (OGg, N = 16. The data were compared to those obtained for women of normal weight (CG, N = 11 and for obese women (OG, N = 12. Eight patients in each group were monitored for one year, with the determination of BMD, of serum calcium, phosphorus, magnesium, parathyroid hormone, 25-hydroxyvitamin D, insulin-like growth factor-I (IGF-I and osteocalcin, and of urinary calcium and deoxypyridinoline. The biochemical determinations were repeated every three months in the longitudinal study and BMD was measured at the end of the study. Parathyroid hormone levels were similar in the three groups. IGF-I levels (CG = 332 ± 62 vs OG = 230 ± 37 vs OGg = 128 ± 19 ng/mL were significantly lower in the operated patients compared to the non-operated obese women. Only OGg patients presented a significant fall in BMD of 6.2% at L1-L4, of 10.2% in the femoral neck, and of 5.1% in the forearm. These results suggest that the weight loss induced by BS is associated with a significant loss of bone mass even at sites that are not influenced by weight overload, with hormonal factors such as IGF-I being associated with this process.

Factors affecting bone mineral mass loss after lower-limb fractures in a pediatric population.

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Ceroni, Dimitri; Martin, Xavier; Kherad, Omar; Salvo, Davide; Dubois-Ferrière, Victor

2015-06-01

The purpose of this study was to assess the effects of the durations of cast immobilization and non-weight-bearing periods, and decreases in vigorous physical activity (VPA) on bone mineral parameters in a pediatric population treated for a lower-limb fracture. Fifty children and teenagers who had undergone a cast-mediated immobilization for a leg or ankle fracture were prospectively recruited. The durations of cast immobilization and non-weight-bearing periods were recorded for each participant. Dual-energy x-ray absorptiometry scans were performed at the time of fracture treatment (baseline) and at cast removal. Physical activity during cast immobilization was assessed using accelerometers. A strong negative correlation was found between the total duration of cast immobilization and decreases in both calcaneal bone mineral density (BMD) (r=-0.497) and total lower-limb bone mineral content (BMC) (r=-0.405). A strong negative correlation was also noted between the durations of the non-weight-bearing periods and alterations in calcaneal BMD (r=-0.420). No apparent correlations were found between lower BMD and BMC and decreased VPA. Bone mineral loss was correlated to the total duration of cast immobilization for all measurement sites on the affected leg, whereas it was only correlated to the durations of non-weight-bearing periods for calcaneal BMD and total lower-limb BMC. However, no correlations were noted between bone mineral loss and decreased VPA.

Human adipose-derived mesenchymal stem cell-conditioned media suppresses inflammatory bone loss in a lipopolysaccharide-induced murine model.

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Li, Yu; Gao, Xin; Wang, Jinbing

2018-02-01

Conditioned media (CM) from mesenchymal stem cells (MSCs) contains various cytokines, growth factors and microRNAs, which may serve important roles in modulating the inflammatory process. However, the effect of MSC-CM on inflammatory bone loss remains unknown. The present study investigated the effects of conditioned media from human adipose-derived mesenchymal stem cells (AMSC-CM) on the prevention of lipopolysaccharide (LPS)-mediated bone loss in mice. To investigate the underlying mechanisms of this effect, the effects of AMSC-CM on serum levels of inflammation-associated cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6 and IL-10] in LPS-treated mice, in addition to their mRNA expression in LPS-treated macrophages, was investigated. Micro-computed tomography and histological analysis revealed that AMSC-CM administration effectively inhibited LPS-induced bone destruction in vivo . ELISA analysis indicated that AMSC-CM significantly reduced the serum levels of proinflammatory cytokines (TNF-α, IL-1 and IL-6) in LPS-treated mice. Furthermore, AMSC-CM treatment significantly decreased the mRNA expression levels of TNF-α, IL-1 and IL-6 in macrophages treated with LPS. These findings indicate that AMSC-CM inhibits LPS-induced bone loss by decreasing the production of proinflammatory cytokines, suggesting that the use of AMSC-CM may be a potential therapeutic strategy for the treatment of inflammatory bone loss.

Irreversible processes kinetic theory

CERN Document Server

Brush, Stephen G

2013-01-01

Kinetic Theory, Volume 2: Irreversible Processes deals with the kinetic theory of gases and the irreversible processes they undergo. It includes the two papers by James Clerk Maxwell and Ludwig Boltzmann in which the basic equations for transport processes in gases are formulated, together with the first derivation of Boltzmann's ""H-theorem"" and a discussion of this theorem, along with the problem of irreversibility.Comprised of 10 chapters, this volume begins with an introduction to the fundamental nature of heat and of gases, along with Boltzmann's work on the kinetic theory of gases and s

Association of stressful life events with accelerated bone loss in older men: the Osteoporotic Fractures in Men (MrOS) Study

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Fink, Howard A.; Kuskowski, Michael A.; Cauley, Jane A.; Taylor, Brent C.; Schousboe, John T.; Cawthon, Peggy M.; Ensrud, Kristine E.

2015-01-01

Purpose/Introduction Prior studies suggest that stressful life events may increase adverse health outcomes, including falls and possibly fractures. The current study builds on these findings and examines whether stressful life events are associated with increased bone loss. Methods 4388 men aged ≥65 years in the Osteoporotic Fractures in Men study completed total hip bone mineral density (BMD) measures at baseline and visit 2, approximately 4.6 years later, and self-reported stressful life events data mid-way between baseline and visit 2, and at visit 2. We used linear regression to model the association of stressful life events with concurrent annualized total hip BMD loss, and log binomial regression or Poisson regression to model risk of concurrent accelerated BMD loss (>1 SD more than mean annualized change). Results 75.3% of men reported ≥1 type of stressful life event, including 43.3% with ≥2 types of stressful life events. Mean annualized BMD loss was −0.36% (SD 0.88) and 13.9% of men were categorized with accelerated BMD loss (about 5.7% or more total loss). Rate of annualized BMD loss increased with the number of types of stressful life events after adjustment for age (pstressful life events (RR, 1.10 [95% CI, 1.04–1.16]) per increase of 1 type of stressful life event). Fracture risk was not significantly different between stressful life event-accelerated bone loss subgroups (p=0.08). Conclusions In these older men, stressful life events were associated with a small, dose-related increase in risk of concurrent accelerated hip bone loss. Low frequency of fractures limited assessment of whether rapid bone loss mediates any association of stressful life events with incident fractures. Future studies are needed to confirm these findings and to investigate the mechanism that may underlie this association. PMID:25169421

Effect of alendronate on early bone loss of renal transplant recipients.

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Abediazar, S; Nakhjavani, M R

2011-03-01

Renal transplant recipients (RTRs) are at risk of developing osteoporosis and osteopenia due to underlying renal osteodystrophy, hypophosphatemia, and immunosuppression. This process occurs more frequently in the first year after renal transplantation (RTX), resulting in eventual bone loss and fractures. The purpose of this study was to evaluate the effect of low-dose alendronate to prevent early bone loss after RTX. We prospectively studied 43 successful RTR including 22 men and 21-women with a mean overall age of 39.16±11.73 years, mean body mass index of 23.6±3.73, and mean dialysis duration of 25.73±17.67 months. We matched them based on age and sex: the alendronate-treated group received vitamin D (Vit D) during the study plus 30 mg alendronate weekly from 1 month after RTX. The control group only received Vit D. We measured serum calcium, phosphate, alkaline phosphatase, blood urea, creatinine, and intact parathyroid hormone (iPTH) at the pretransplant baseline and monthly thereafter as well as BMD of the lumbar spine, femur, and radius pretransplant baseline versus 3 and 6 months after RTX. At 6 month after RTX, the lumbar BMD in the alendronate group increased significantly from 0.819±0.11 to 0.863±0.14 (Pbone loss and increase BMD immediately after RTX. Copyright © 2011. Published by Elsevier Inc.

Severe Bone Loss induced by Orthodontic Elastic Separator: A Rare Case Report

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A E Vishwanath

2013-01-01

Full Text Available A displaced orthodontic elastic separator was proposed as being the source of a gingival abscess that progressed to severe bone loss and exfoliation in a healthy adolescent patient with sound periodontal status prior to commencement of orthodontic treatment. After 1 year of undergoing orthodontic treatment, the patient presented with dull pain and mobility in the left upper permanent molar for which there was no apparent etiology. On clinical examination, the patient had gingival inflammation, associated with a deep pocket and severe mobility (grade III in relation to the same teeth. Radiographic examination of an orthopantomogram and intraoral periapical radiography (IOPAR revealed a chronic periodontal abscess with severe necrosis of the periodontal ligament and severe alveolar bone loss. A radiopaque mass on the distal surface below the cementoenamel junction (CEJ was also observed. The patient was referred to the department of periodontics for assessment and appropriate treatment. On curettage, it was found that there was orthodontic elastic separator which was displaced subgingivally.

Bone loss in rheumatoid arthritis

International Nuclear Information System (INIS)

Gotfredsen, A.; Als, O.S.; Hassager, C.; Christiansen, C.

1986-01-01

The authors studied 159 patients with rheumatoid arthritis (RA) treated with a variety of drugs. Stratification of the patients was done according to treatment, sex, menopausal state, duration of the disease, and functional impairment. Forearm bone mineral content (BMC) and total body bone mineral (TBBM) were measured by single and dual photon absorptiometry. Bone turnover was estimated by biochemical markers. All patients had significantly decreased BMC and TBBM compared to normals. Comparing glucocorticoid and penicillamine treatment in premenopausal patients, they found significantly lower BMC and TBBM values in the glucocorticoid treated group. However, no differences in BMC and TBBM values were found in the corresponding postmenopausal groups. In the premenopausal glucocorticoid group with the duration of treatment and cumulated dose correlated with BMC, whereas no such correlations were found in the postmenopausal women. In the patients who did not receive glucocorticoids they found significant relationships between BMC and functional impairment as well as duration of the disease. Indices of bone turnover rose with increasing functional, impairment, particularly those of bone resorption

A full-mouth radiographic survey of periodontal bone loss in dogs

International Nuclear Information System (INIS)

Pavlica, Z.; Erjavec, V.; Erzen, D.; Petelin, M.

2003-01-01

The objective of this study was to evaluate the relationship between clinically observed periodontal disease indicators and radiographic findings using fullmouth radiographs in poodles. The dogs were divided into three groups according to their age. Upper and lower incisors, canines and premolars/molars were used for clinical and radiographic analyses. The prevalence and severity of periodontal disease increased with age. In addition, the deepest pockets and most severe bone loss were found around the canine teeth. The values obtained from radiographic analysis correlated well with clinical measurements. Fullmouth radiographic surveys show clearly the alveolar bone level around the whole dentition of dogs. It should be performed prior to the institution of any treatment

Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

International Nuclear Information System (INIS)

Wang Hao; Wu Guo-Xing

2013-01-01

An irreversible Ericsson refrigeration cycle model is established, in which multi-irreversibilities such as finite-rate heat transfer, regenerative loss, heat leakage, and the efficiency of the regenerator are taken into account. Expressions for several important performance parameters, such as the cooling rate, coefficient of performance (COP), power input, exergy output rate, entropy generation rate, and ecological function are derived. The influences of the heat leakage and the time of the regenerative processes on the ecological performance of the refrigerator are analyzed. The optimal regions of the ecological function, cooling rate, and COP are determined and evaluated. Furthermore, some important parameter relations of the refrigerator are revealed and discussed in detail. The results obtained here have general significance and will be helpful in gaining a deep understanding of the magnetic Ericsson refrigeration cycle. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Identification of induced and naturally occurring conductive hearing loss in mice using bone conduction.

Science.gov (United States)

Chhan, David; McKinnon, Melissa L; Rosowski, John J

2017-03-01

While many mouse models of hearing loss have been described, a significant fraction of the genetic defects in these models affect both the inner ear and middle ears. A common method used to separate inner-ear (sensory-neural) from middle-ear (conductive) pathologies in the hearing clinic is the combination of air-conduction and bone-conduction audiometry. In this report, we investigate the use of air- and bone-conducted evoked auditory brainstem responses to perform a similar separation in mice. We describe a technique by which we stimulate the mouse ear both acoustically and via whole-head vibration. We investigate the sensitivity of this technique to conductive hearing loss by introducing middle-ear lesions in normal hearing mice. We also use the technique to investigate the presence of an age-related conductive hearing loss in a common mouse model of presbycusis, the BALB/c mouse. Copyright © 2017 Elsevier B.V. All rights reserved.

Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

International Nuclear Information System (INIS)

Tyagi, S K; Kaushik, S C; Salhotra, R

2002-01-01

The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency

Performance characteristics and parametric optimization of an irreversible magnetic Ericsson heat-pump

International Nuclear Information System (INIS)

Wei Fang; Lin Guoxing; Chen Jincan; Brueck, Ekkes

2011-01-01

Taking into account the finite-rate heat transfer in the heat-transfer processes, heat leak between the two external heat reservoirs, regenerative loss, regeneration time, and internal irreversibility due to dissipation of the cycle working substance, an irreversible magnetic Ericsson heat-pump cycle is presented. On the basis of the thermodynamic properties of magnetic materials, the performance characteristics of the irreversible magnetic Ericsson heat-pump are investigated and the relationship between the optimal heating load and the coefficient of performance (COP) is derived. Moreover, the maximum heating load and the corresponding COP as well as the maximum COP and the corresponding heating load are obtained. Furthermore, the other optimal performance characteristics are discussed in detail. The results obtained here may provide some new information for the optimal parameter design and the development of real magnetic Ericsson heat-pumps. -- Research Highlights: →The effects of multi-irreversibilities on the performance of a magnetic heat-pump are revealed. →Mathematical expressions of the heating load and the COP are derived and the optimal performance and operating parameters are analyzed and discussed. →Several important performance bounds are determined.

Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

Science.gov (United States)

Tyagi, S. K.; Kaushik, S. C.; Salhotra, R.

2002-10-01

The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency.

Irreversible performance of a quantum harmonic heat engine

Science.gov (United States)

Rezek, Yair; Kosloff, Ronnie

2006-05-01

The unavoidable irreversible loss of power in a heat engine is found to be of quantum origin. Following thermodynamic tradition, a model quantum heat engine operating in an Otto cycle is analysed, where the working medium is composed of an ensemble of harmonic oscillators and changes in volume correspond to changes in the curvature of the potential well. Equations of motion for quantum observables are derived for the complete cycle of operation. These observables are sufficient to determine the state of the system and with it all thermodynamical variables. Once the external controls are set, the engine settles to a limit cycle. Conditions for optimal work, power and entropy production are derived. At high temperatures and quasistatic operating conditions, the efficiency at maximum power coincides with the endoreversible result \\eta_q=1-\\sqrt{{T_c}/{T_h}} . The optimal compression ratio varies from {\\cal C} =\\sqrt{T_h/T_c} in the quasistatic limit where the irreversibility is dominated by heat conductance to {\\cal C} =(T_h/T_c)^{1/4} in the sudden limit when the irreversibility is dominated by friction. When the engine deviates from adiabatic conditions, the performance is subject to friction. The origin of this friction can be traced to the noncommutability of the kinetic and potential energy of the working medium.

Cytokines and T-lymphocyte subsets in healthy post-menopausal women: estrogen retards bone loss without affecting the release of IL-1 or IL-1ra

DEFF Research Database (Denmark)

Abrahamsen, Bo; Bendtzen, Klaus; Beck-Nielsen, H

1997-01-01

resorptive cytokines and have also been linked with bone metabolism and the development of osteoporosis. Cytokine secretion from whole blood cell cultures was compared between two randomized groups of healthy early post-menopausal women (mean age 52.5 yrs, N = 91) and lymphocyte subsets were quantitated....... There was no association between cytokine release and bone mass or loss assessed over 2 yrs. The only exception was a weak estrogen-independent correlation between basal IL-1ra secretion and bone loss (r = -0.21, p loss...... cells may be important in the pathophysiology of post-menopausal bone loss. The possibility that IL-1ra acts as an independent bone-sparing factor unrelated to estrogen withdrawal warrants further investigation. In conclusion, ERT maintains bone without affecting the release of the IL-1 family...

A well-balanced diet combined or not with exercise induces fat mass loss without any decrease of bone mass despite bone micro-architecture alterations in obese rat.

Science.gov (United States)

Gerbaix, Maude; Metz, Lore; Mac-Way, Fabrice; Lavet, Cédric; Guillet, Christelle; Walrand, Stéphane; Masgrau, Aurélie; Vico, Laurence; Courteix, Daniel

2013-04-01

The association of a well-balanced diet with exercise is a key strategy to treat obesity. However, weight loss is linked to an accelerated bone loss. Furthermore, exercise is known to induce beneficial effects on bone. We investigated the impact of a well-balanced isoenergetic reducing diet (WBR) and exercise on bone tissue in obese rats. Sixty male rats had previously been fed with a high fat/high sucrose diet (HF/HS) for 4months to induce obesity. Then, 4 regimens were initiated for 2months: HF/HS diet plus exercise (treadmill: 50min/day, 5days/week), WBR diet plus exercise, HF/HS diet plus inactivity and WBR diet plus inactivity. Body composition and total BMD were assessed using DXA and visceral fat mass was weighed. Tibia densitometry was assessed by Piximus. Bone histomorphometry was performed on the proximal metaphysis of tibia and on L2 vertebrae (L2). Trabecular micro-architectural parameters were measured on tibia and L2 by 3D microtomography. Plasma concentration of osteocalcin and CTX were measured. Both WBR diet and exercise had decreased global weight, global fat and visceral fat mass (pdiet alone failed to alter total and tibia bone mass and BMD. However, Tb.Th, bone volume density and degree of anisotropy of tibia were decreased by the WBR diet (pdiet had involved a significant lower MS/BS and BFR/BS in L2 (pdiet inducing weight and fat mass losses did not affected bone mass and BMD of obese rats despite alterations of their bone micro-architecture. The moderate intensity exercise performed had improved the tibia BMD of obese rats without any trabecular and cortical adaptation. Copyright © 2013 Elsevier Inc. All rights reserved.

Diagnosis of osteoarthritis and prognosis of tibial cartilage loss by quantification of tibia trabecular bone from MRI

DEFF Research Database (Denmark)

Marques, Joselene; Genant, Harry K.; Lillholm, Martin

2013-01-01

loss were assessed by a segmentation process. Aiming to quantify and potentially capture the structure of the trabecular bone anatomy, a machine learning approach used a set of texture features for training a classifier to recognize the trabecular bone of a knee with radiographic osteoarthritis. Using...

Evidence for the prevention of bone loss in elderly and old early non-metastatic breast cancer patients treated with aromatase inhibitors

DEFF Research Database (Denmark)

Gunmalm, V.; Jørgensen, N. R.; Abrahamsen, B.

2017-01-01

Breast cancer (BC) is the most common cancer amongst women worldwide. Bone health is emerging as an important issue for BC survivors. In this literature study, we focus on agents for preventing bone loss in early non-metastatic estrogen receptor positive BC in treatment with aromatase inhibitors...... (AI) and to assess the evidence for antiresorptive treatment of bone loss in early non-metastatic breast cancer. We included randomized controlled trials (RCT's) comparing: (a) bisphosphonates and control; (b) different bisphosphonates; (c) denosumab and control and (d) bisphosphonates vs. denosumab...... in early non-metastatic BC women in AI treatment. Among antiresorptives, zoledronic acid currently has the highest evidence for prevention of AI associated bone loss in early non-metastatic BC. Data on fracture prevention among all patients, elderly and old is sparse. More randomized controlled studies...

Suppressor of cytokine signaling 1 expression during LPS-induced inflammation and bone loss in rats

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João Antonio Chaves de SOUZA

2017-10-01

Full Text Available Abstract This study aimed to characterize the dynamics of suppressor of cytokine signaling (SOCS1 expression in a rat model of lipopolysaccharide-induced periodontitis. Wistar rats in the experimental groups were injected three times/week with LPS from Escherichia coli on the palatal aspect of the first molars, and control animals were injected with vehicle (phosphate-buffered saline. Animals were sacrificed 7, 15, and 30 days after the first injection to analyze inflammation (stereometric analysis, bone loss (macroscopic analysis, gene expression (qRT-PCR, and protein expression/activation (Western blotting. The severity of inflammation and bone loss associated with LPS-induced periodontitis increased from day 7 to day 15, and it was sustained through day 30. Significant (p < 0.05 increases in SOCS1, RANKL, OPG, and IFN-γ gene expression were observed in the experimental group versus the control group at day 15. SOCS1 protein expression and STAT1 and NF-κB activation were increased throughout the 30-day experimental period. Gingival tissues affected by experimental periodontitis express SOCS1, indicating that this protein may potentially downregulate signaling events involved in inflammatory reactions and bone loss and thus may play a relevant role in the development and progression of periodontal disease.

Depression and risk of fracture and bone loss: an updated meta-analysis of prospective studies.

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Wu, Q; Liu, B; Tonmoy, S

2018-03-12

This meta-analysis pooled results from 23 qualifying individual cohort studies and found that depression was significantly associated with an increased risk of fractures and bone loss. The association between depression and risk of fracture remains controversial. We conducted a comprehensive meta-analysis to examine the effect of depression on the risk of osteoporotic fractures and bone loss. We searched databases and reviewed citations in relevant articles for eligible cohort studies. Two investigators independently conducted study selection, appraisal, and data abstraction through the use of a standardized protocol. Random effect models were used for meta-analysis. Cochrane Q and I 2 statistics were used to assess heterogeneity. Funnel plots and rank correlation tests were used to evaluate publication bias. Twenty-three studies were included for meta-analysis. In studies that reported hazard ratio (HR) as the outcome (nine studies [n = 309,862]), depression was associated with 26% increase in fracture risk (HR = 1.26, 95% CI, 1.10-1.43, p meta-analysis having modified inclusion criteria and in different subgroup analyses as well. Significant heterogeneity was observed in the meta-analysis; however, no significant publication bias was detected. Depression is associated with a significant increased risk in fracture and bone loss. Effective prevention may decrease such risk.

Prevention of bone loss by vitamin D supplementation in elderly women : A randomized double-blind trial

NARCIS (Netherlands)

Ooms, Marcel E.; Roos, Jan C.; Bezemer, P. Dick; van der Vijgh, Wim J F; Bouter, Lex M.; Lips, Paul

1995-01-01

The purpose of the study was to determine the effect of vitamin D supplementation on bone turnover and bone loss in elderly women. Three hundred forty-eight women, ages 70 yr and older, were randomized to receive 400 IU vitamin D3 per day (n = 177) or placebo (n = 171), double-blind, for a period of

Systemic Mesenchymal Stromal Cell Transplantation Prevents Functional Bone Loss in a Mouse Model of Age-Related Osteoporosis.

Science.gov (United States)

Kiernan, Jeffrey; Hu, Sally; Grynpas, Marc D; Davies, John E; Stanford, William L

2016-05-01

Age-related osteoporosis is driven by defects in the tissue-resident mesenchymal stromal cells (MSCs), a heterogeneous population of musculoskeletal progenitors that includes skeletal stem cells. MSC decline leads to reduced bone formation, causing loss of bone volume and the breakdown of bony microarchitecture crucial to trabecular strength. Furthermore, the low-turnover state precipitated by MSC loss leads to low-quality bone that is unable to perform remodeling-mediated maintenance--replacing old damaged bone with new healthy tissue. Using minimally expanded exogenous MSCs injected systemically into a mouse model of human age-related osteoporosis, we show long-term engraftment and markedly increased bone formation. This led to improved bone quality and turnover and, importantly, sustained microarchitectural competence. These data establish proof of concept that MSC transplantation may be used to prevent or treat human age-related osteoporosis. This study shows that a single dose of minimally expanded mesenchymal stromal cells (MSCs) injected systemically into a mouse model of human age-related osteoporosis display long-term engraftment and prevent the decline in bone formation, bone quality, and microarchitectural competence. This work adds to a growing body of evidence suggesting that the decline of MSCs associated with age-related osteoporosis is a major transformative event in the progression of the disease. Furthermore, it establishes proof of concept that MSC transplantation may be a viable therapeutic strategy to treat or prevent human age-related osteoporosis. ©AlphaMed Press.

Single-nucleotide polymorphisms in the P2X7 receptor gene are associated with post-menopausal bone loss and vertebral fractures

DEFF Research Database (Denmark)

Rye Jørgensen, Niklas; Husted, Lise Bjerre; Skarratt, Kristen K

2012-01-01

to bone mass and fracture incidence in post-menopausal women. A total of 1694 women (aged 45-58) participating in the Danish Osteoporosis Prevention Study were genotyped for 12 functional P2X7 receptor variants. Bone mineral density was determined at baseline and after 10 years. In addition, vertebral...... had increased bone loss. In contrast, the Gln460Arg polymorphism was associated with protection against bone loss. The Ala348Thr polymorphism was associated with a lower vertebral fracture incidence 10 years after menopause. Finally, we developed a risk model, which integrated P2RX7 genotypes. Using...

MicroCT evaluation of bone mineral density loss in human bones

International Nuclear Information System (INIS)

Nogueira, Liebert P.; Braz, Delson; Lopes, Ricardo T.; Barroso, Regina C.; Oliveira, Luis F.

2007-01-01

Bone is a connective tissue largely composed of an organic protein, collagen and the inorganic mineral hydroxyapatite [Ca 10 (PO 4 ) 6 OH 2 ], which combine to provide a mechanical and supportive role in the body. Depending on the orientation of collagen fibers, two types of bone can be distinguished: trabecular and cortical bone. Degree of mineralization is considered an important feature of bone quality. Changes in the degree of mineralization is generally due to osteoporosis, but many recent studies have already shown that alterations in degree of mineralization can occur due to a large variety of factors. The transmission X-ray microtomography is one of the most popular methods, which provides the spatial distribution of the total absorption coefficient inside the sample. The aim of this study was to investigate the suitability of using microCT as a supplementary tool for the diagnosis of the health status of human bones. Eleven samples were constructed simulating the physiological range of bone mineral density (BMD) found in cortical human bone. The samples represent healthy mixtures of swine compact bone dried at room temperature, powdered and mixed with fat (0 - 100 % by mass). The samples were imaged by a microfocus tube (Fein-Focus) with focal size of about 60 μm (±5%), and a CCD camera (0.143 mm pixel size) coupled with an intensifier tube with fluoroscope screen at the Nuclear Instrumentation Laboratory (COPPE/UFRJ), Brazil. The images were reconstructed and treated with suitable software developed at the Nuclear Instrumentation Laboratory. The mineral content in cortical bone is defined by the volume of dry, fat-free bone per unit bulk volume of the bone. The volumes were calculated from the bone density using the relationship between volume and density. The densities of fat and bone were taken to be 0.95 g.cm -3 and 1.92 g.cm -3 respectively. The correlation of the measured absorption coefficient with the mineral content in the samples was then

MicroCT evaluation of bone mineral density loss in human bones

Energy Technology Data Exchange (ETDEWEB)

Nogueira, Liebert P.; Braz, Delson; Lopes, Ricardo T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mails: lnogueira@con.ufrj.br; Barroso, Regina C.; Oliveira, Luis F. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: cely@uerj.br

2007-07-01

Bone is a connective tissue largely composed of an organic protein, collagen and the inorganic mineral hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}OH{sub 2}], which combine to provide a mechanical and supportive role in the body. Depending on the orientation of collagen fibers, two types of bone can be distinguished: trabecular and cortical bone. Degree of mineralization is considered an important feature of bone quality. Changes in the degree of mineralization is generally due to osteoporosis, but many recent studies have already shown that alterations in degree of mineralization can occur due to a large variety of factors. The transmission X-ray microtomography is one of the most popular methods, which provides the spatial distribution of the total absorption coefficient inside the sample. The aim of this study was to investigate the suitability of using microCT as a supplementary tool for the diagnosis of the health status of human bones. Eleven samples were constructed simulating the physiological range of bone mineral density (BMD) found in cortical human bone. The samples represent healthy mixtures of swine compact bone dried at room temperature, powdered and mixed with fat (0 - 100 % by mass). The samples were imaged by a microfocus tube (Fein-Focus) with focal size of about 60 {mu}m ({+-}5%), and a CCD camera (0.143 mm pixel size) coupled with an intensifier tube with fluoroscope screen at the Nuclear Instrumentation Laboratory (COPPE/UFRJ), Brazil. The images were reconstructed and treated with suitable software developed at the Nuclear Instrumentation Laboratory. The mineral content in cortical bone is defined by the volume of dry, fat-free bone per unit bulk volume of the bone. The volumes were calculated from the bone density using the relationship between volume and density. The densities of fat and bone were taken to be 0.95 g.cm{sup -3} and 1.92 g.cm{sup -3} respectively. The correlation of the measured absorption coefficient with the mineral content

Protective effect of Rhizoma Dioscoreae extract against alveolar bone loss in ovariectomized rats via regulation of IL-6/STAT3 signaling.

Science.gov (United States)

Zhang, Zhi-Guo; Chen, Yan-Jing; Xiang, Li-Hua; Pan, Jing-Hua; Wang, Zhen; Xiao, Gary Guishan; Ju, Da-Hong

2017-11-01

The aim of the present study was to assess the effectiveness of Rhizoma Dioscoreae extract (RDE) on preventing rat alveolar bone loss induced by ovariectomy (OVX), and to determine the role of interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in this effect. Female Wistar rats were subjected to OVX or sham surgery. The rats that had undergone OVX were treated with RDE (RDE group), vehicle (OVX group) or 17β-estradiol subcutaneous injection (E2 group). Subsequently, bone metabolic activity was assessed by analyzing 3-D alveolar bone construction, bone mineral density, as well as the plasma biomarkers of bone turnover. The gene expression of alveolar bone in the OVX and RDE groups was evaluated by IL-6/STAT3 signaling pathway polymerase chain reaction (PCR) arrays, and differentially expressed genes were determined through reverse transcription-quantitative PCR. The inhibitory effect of RDE on alveolar bone loss in the OVX group was demonstrated in the study. In comparison with the OVX group, the RDE group exhibited 19 downregulated genes and 1 upregulated gene associated with the IL-6/STAT3 signaling pathway in alveolar bone. Thus, RDE was shown to relieve OVX-induced alveolar bone loss in rats, an effect which was likely associated with decreased abnormal bone remodeling via regulation of the IL-6/STAT3 signaling pathway.

Irreversibility and self-organization in spin glasses. 1. Origin of irreversibility in spin glasses

International Nuclear Information System (INIS)

Kovrov, V.P.; Kurbatov, A.M.

1989-05-01

The origin of irreversibility in spin glasses is found out on the basis of the analytical study of the well-known TAP equations. Connection between irreversible jumpwise transitions and a positive feedback in spin glasses is discussed. (author). 7 refs, 4 figs

Protection against T1DM-Induced Bone Loss by Zinc Supplementation: Biomechanical, Histomorphometric, and Molecular Analyses in STZ-Induced Diabetic Rats.

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Raul Hernandes Bortolin

Full Text Available Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM, and T1DM plus zinc supplementation (T1DMS. Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young's modulus, and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic

Evaluation of bone loss due to primary occlusal trauma in two experimental models of occlusal overload

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Ana Cristina Távora de Albuquerque LOPES

Full Text Available Abstract Introduction Primary occlusal trauma (OT is an injury of the periodontium with normal height as a result of occlusal forces which exceed their adaptive capacity. Objective To evaluate, histometrically, the alveolar bone loss in the furcation region of rats experimentally submitted to 2 models of occlusal overload. Material and method 45 animals randomly divided into 3 groups: Occlusal Interference (OI, n = 15 - fixing an orthodontic wire segment on the occlusal surface of the first lower molar; Occlusal Overload (OO, n = 15 - wearing of the cusps of the lower contralateral molars, the second and third molars next to the first molar that had its dimensions maintained; Negative Control (NC, n = 15 - evaluation of the initial dimensions of the periodontal ligament (PL. Five animals / group were sacrificed after 14, 21 and 28 days. Result Intergroup evaluation showed significant bone loss in OI (p0.05. The thickness of the PL remained stable in NC (p>0.05. Conclusion OI and OO were effective in the experimental reproduction of OT, and OI promoted greater alveolar bone loss compared to OO, showing that the impact of occlusal overload in OI increased the extent of the OT injury.

An altered hormonal profile and elevated rate of bone loss are associated with low bone mass in professional horse-racing jockeys.

Science.gov (United States)

Dolan, Eimear; McGoldrick, Adrian; Davenport, Colin; Kelleher, Grainne; Byrne, Brendan; Tormey, William; Smith, Diarmuid; Warrington, Giles D

2012-09-01

Horse-racing jockeys are a group of weight-restricted athletes, who have been suggested as undertaking rapid and extreme weight cycling practices in order to comply with stipulated body-mass standards. The aim of this study was to examine bone mass, turnover and endocrine function in jockeys and to compare this group with age, gender and body mass index matched controls. Twenty male professional jockeys and 20 healthy male controls participated. Dual energy X-ray absorptiometry scans and early morning fasting blood and urine samples were used to measure bone mass, turnover and a hormonal profile. Total body bone mineral density (BMD) was significantly lower in jockeys (1.143 ± 0.05 vs. 1.27 ± 0.06 g cm(-3), p professional jockeys have an elevated rate of bone loss and reduced bone mass that appears to be associated with disrupted hormonal activity. It is likely that this may have occurred in response to the chronic weight cycling habitually experienced by this group.

Endodontic therapy of a mandibular canine tooth with irreversible pulpitis secondary to dentigerous cyst.

Science.gov (United States)

MacGee, Scott

2014-01-01

Dentigerous cysts are uncommon, yet are being reported with increasing frequency in the veterinary literature. Dentigerous cysts are a type of benign odontogenic cyst associated with impacted teeth, most commonly the mandibular first premolar tooth. Significant bone destruction can occur secondary to the expansion of a dentigerous cyst. The expanding cyst can lead to pathology of neighboring teeth, which can include external root resorption or pulpitis. Intraoral dental radiographs are imperative to properly assess the presence and extent of a dentigerous cyst, as well as the status of the neighboring teeth. This case report describes treatment for dentigerous cyst including cyst lining curettage, mandibular bone regeneration, and endodontic therapy for a canine tooth with irreversible pulpitis.

Exercise Countermeasures for Bone Loss During Space Flight: A Method for the Study of Ground Reaction Forces and their Implications for Bone Strain

Science.gov (United States)

Peterman, M.; McCrory, J. L.; Sharkey, N. A.; Piazza, S.; Cavanagh, P. R.

1999-01-01

Effective countermeasures to prevent loss of bone mineral during long duration space flight remain elusive. Despite an exercise program on MIR flights, the data from LeBlanc et al. (1996) indicated that there was still a mean rate of loss of bone mineral density in the proximal femur of 1.58% per month (n=18, flight duration 4 - 14.4 months). The specific mechanisms regulating bone mass are not known, but most investigators agree that bone maintenance is largely dependent upon mechanical demand and the resultant local bone strains. A plausible hypothesis is that bone loss during space flight, such as that reported by LeBlanc et al. (1996), may result from failure to effectively load the skeleton in order to generate localized bone strains of sufficient magnitude to prevent disuse osteoporosis. A variety of methods have been proposed to simulate locomotor exercise in reduced gravity. In such simulations, and in an actual microgravity environment, a gravity replacement load (GRL) must always be added to return the exercising subject to the support surface and the resulting skeletal load is critically dependent upon the magnitude of the GRL. To our knowledge, GRLs during orbital flight have only been measured once (on STS 81) and it is likely that most or all prior treadmill exercise in space has used GRLs that were less than one body weight. McCrory (1997) has shown that subjects walking and running in simulated zero-G can tolerate GRLs of 1 if an appropriate harness is used. Several investigators have attempted to measure in vivo strains and forces in the bones of humans, but have faced ethical and technical limitations. The anteromedial aspect of the tibial midshaft has been a common site for the placement of strain gauges; one reason to measure strains in the anterior tibia is that this region is surgically accessible. Aamodt et al. (1997) were able to measure strains on the lateral surface of the proximal femur only because their experimental subjects were

Marked disparity between trabecular and cortical bone loss with age in healthy men. Measurement by vertebral computed tomography and radial photon absorptiometry

International Nuclear Information System (INIS)

Meier, D.E.; Orwoll, E.S.; Jones, J.M.

1984-01-01

To define age-related changes in bone mineral content in normal men, we measured radial (proximal and distal) and vertebral bone mineral content in 62 men aged 30 to 92 years. Radial bone mineral content (largely cortical bone) was measured by single photon absorptiometry, and trabecular vertebral content (T12, L1 to L3) by computed tomography. Radial bone mineral content fell gradually (2% to 3.4% per decade) with age, but vertebral trabecular content fell more rapidly (12% per decade). Body size was not associated with the rate of bone loss from the distal radial and vertebral sites, but men with lower surface areas lost bone more rapidly at the predominantly cortical proximal radial site. The fact that radial cortical bone mineral content falls much less rapidly than vertebral trabecular content with age and is also associated with surface area indicates that trabecular and cortical bone compartments may be independently modulated. Age-related bone loss should not be considered a homogeneous process

Suppression Effect of Astaxanthin on Osteoclast Formation In Vitro and Bone Loss In Vivo

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Yun-Ho Hwang

2018-03-01

Full Text Available Osteoporosis is characterized by a reduction of the bone mineral density (BMD and microarchitectural deterioration of the bone, which lead to bone fragility and susceptibility to fracture. Astaxanthin (AST has a variety of biological activities, such as a protective effect against asthma or neuroinflammation, antioxidant effect, and decrease of the osteoclast number in the right mandibles in the periodontitis model. Although treatment with AST is known to have an effect on inflammation, no studies on the effect of AST exposure on bone loss have been performed. Thus, in the present study, we examined the antiosteoporotic effect of AST on bone mass in ovariectomized (OVX mice and its possible mechanism of action. The administration of AST (5, 10 mg/kg for 6 weeks suppressed the enhancement of serum calcium, inorganic phosphorus, alkaline phosphatase, total cholesterol, and tartrate-resistant acid phosphatase (TRAP activity. The bone mineral density (BMD and bone microarchitecture of the trabecular bone in the tibia and femur were recovered by AST exposure. Moreover, in the in vitro experiment, we demonstrated that AST inhibits osteoclast formation through the expression of the nuclear factor of activated T cells (NFAT c1, dendritic cell-specific transmembrane protein (DC-STAMP, TRAP, and cathepsin K without any cytotoxic effects on bone marrow-derived macrophages (BMMs. Therefore, we suggest that AST may have therapeutic potential for the treatment of postmenopausal osteoporosis.

Effects of electromagnetic fields on bone loss in hyperthyroidism rat model.

Science.gov (United States)

Liu, Chaoxu; Zhang, Yingchi; Fu, Tao; Liu, Yang; Wei, Sheng; Yang, Yong; Zhao, Dongming; Zhao, Wenchun; Song, Mingyu; Tang, Xiangyu; Wu, Hua

2017-02-01

Optimal therapeutics for hyperthyroidism-induced osteoporosis are still lacking. As a noninvasive treatment, electromagnetic fields (EMF) have been proven to be effective for treating osteoporosis in non-hyperthyroidism conditions. We herein systematically evaluated the reduced effects of EMF on osteoporosis in a hyperthyroidism rat model. With the use of Helmholtz coils and an EMF stimulator, 15 Hz/1 mT EMF was generated. Forty-eight 5-month-old male Sprague-Dawley rats were randomly divided into four different groups: control, levothyroxine treated (L-T4), EMF exposure + levothyroxine (EMF + L-T4), and EMF exposure without levothyroxine administration (EMF). All rats were treated with L-T4 (100 mg/day) except those in control and EMF groups. After 12 weeks, the results obtained from bone mineral density analyses and bone mechanical measurements showed significant differences between L-T4 and EMF + L-T4 groups. Micro CT and bone histomorphometric analyses indicated that trabecular bone mass and architecture in distal femur and proximal tibia were augmented and restored partially in EMF + L-T4 group. In addition, bone thyroid hormone receptors (THR) expression of hyperthyroidism rats was attenuated in EMF + L-T4 group, compared to control group, which was not observed in L-T4 group. According to these results, we concluded that 15 Hz/1 mT EMF significantly inhibited bone loss and micro architecture deterioration in hyperthyroidism rats, which might occur due to reduced THR expression caused by EMF exposure. Bioelectromagnetics. 38:137-150, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Bone-anchored hearing aids in conductive and mixed hearing losses: why do patients reject them?

Science.gov (United States)

Siau, Richard T K; Dhillon, Baljeet; Siau, Derrick; Green, Kevin M J

2016-10-01

This study aimed to report the bone-anchored hearing aid uptake rate and the reasons for their rejection by patients with conductive and mixed hearing losses. A retrospective review was performed of 113 consecutive patients with unilateral or bilateral conductive or mixed hearing loss referred to the Greater Manchester bone-anchored hearing aid (BAHA) programme between September 2008 and August 2011. 98 (86.7 %) patients were deemed audiologically suitable for BAHA implantation. Of these, 38 (38.8 %) had BAHA implanted; 60 (61.2 %) patients declined. Of those who declined, 27 (45 %) cited anxiety over surgery, 18 (30 %) cited cosmetic reasons, 16 (26.7 %) perceived limited benefit from the device and six (10 %) preferred conventional hearing aids. Our study highlights a 38.8 % BAHA uptake rate in audiologically suitable patients. The main reasons cited for rejection of BAHA were anxiety over surgery and cosmetic concerns. It is important that clinicians address these early during consultation with prospective BAHA recipients and avoid rushing to implant these patients with a bone-anchored hearing aid.

Progesterone and Bone: Actions Promoting Bone Health in Women

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Vanadin Seifert-Klauss

2010-01-01

Full Text Available Estradiol (E2 and progesterone (P4 collaborate within bone remodelling on resorption (E2 and formation (P4. We integrate evidence that P4 may prevent and, with antiresorptives, treat women's osteoporosis. P4 stimulates osteoblast differentiation in vitro. Menarche (E2 and onset of ovulation (P4 both contribute to peak BMD. Meta-analysis of 5 studies confirms that regularly cycling premenopausal women lose bone mineral density (BMD related to subclinical ovulatory disturbances (SODs. Cyclic progestin prevents bone loss in healthy premenopausal women with amenorrhea or SOD. BMD loss is more rapid in perimenopause than postmenopause—decreased bone formation due to P4 deficiency contributes. In 4 placebo-controlled RCTs, BMD loss is not prevented by P4 in postmenopausal women with increased bone turnover. However, 5 studies of E2-MPA co-therapy show greater BMD increases versus E2 alone. P4 fracture data are lacking. P4 prevents bone loss in pre- and possibly perimenopausal women; progesterone co-therapy with antiresorptives may increase bone formation and BMD.

Comparison of two methods for alveolar bone loss measurement in an experimental periodontal disease model in rats

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Diego Nique Liberman

2011-02-01

Full Text Available There are many studies that evaluate possible risk factors for periodontal diseases in animals. Most of them have focused only on the biological aspects of disease occurrence; therefore, it has been difficult to compare studies of the different methodological approaches. The aim of the present study was to compare different methods - linear and area - of the evaluation of morphometrical alveolar bone loss. Sixty hemimaxillae, defleshed and stained with 1% methylene blue to delineate the cementoenamel junction and alveolar bone crest, were obtained from a previous study that induced periodontal disease by means of ligatures in two groups of fifteen Wistar rats during 9 weeks. Ligatures were placed around the right upper second molars, and the contra-lateral teeth remained as intra-group controls. Digital photographs were taken from the specimens and submitted to a single, calibrated, blind examiner who performed the morphometrical evaluation of alveolar bone loss using both linear and area methods. Mean values of linear and area measurements were obtained from each side - buccal and palatal - of the specimens. The degree of association between the two methods was determined by Pearson's Correlation Coefficient. An almost perfect association (0.98 was determined between the linear and area evaluations. A mathematical formula was subsequently created to estimate the total area of alveolar bone loss, from linear mean measurements. Both methods were suitable for detecting bone level alterations. The results of the present study allow for the transformation of data and better compilation of results from different studies.

Influence of surgical and prosthetic techniques on marginal bone loss around titanium implants. Part I: immediate loading in fresh extraction sockets.

Science.gov (United States)

Berberi, Antoine N; Tehini, Georges E; Noujeim, Ziad F; Khairallah, Alexandre A; Abousehlib, Moustafa N; Salameh, Ziad A

2014-10-01

Delayed placement of implant abutments has been associated with peri-implant marginal bone loss; however, long-term results obtained by modifying surgical and prosthetic techniques after implant placement are still lacking. This study aimed to evaluate the marginal bone loss around titanium implants placed in fresh extraction sockets using two loading protocols after a 5-year follow-up period. A total of 36 patients received 40 titanium implants (Astra Tech) intended for single-tooth replacement. Implants were immediately placed into fresh extraction sockets using either a one-stage (immediate loading by placing an interim prosthesis into functional occlusion) or a two-stage prosthetic loading protocol (insertion of abutments after 8 weeks of healing time). Marginal bone levels relative to the implant reference point were evaluated at four time intervals using intraoral radiographs: at time of implant placement, and 1, 3, and 5 years after implant placement. Measurements were obtained from mesial and distal surfaces of each implant (α = 0.05). One-stage immediate implant placement into fresh extraction sockets resulted in a significant reduction in marginal bone loss (p sockets reduced marginal bone loss and did not compromise the success rate of the restorations. © 2014 by the American College of Prosthodontists.

Retaining Residual Ovarian Tissue following Ovarian Failure Has Limited Influence on Bone Loss in Aged Mice

Directory of Open Access Journals (Sweden)

Zelieann R. Craig

2010-01-01

Full Text Available Previous work showed that retaining residual ovarian tissue protects young mice from accelerated bone loss following ovarian failure. The present study was designed to determine whether this protection is also present in aged animals. Aged (9–12 months C57BL/6Hsd female mice were divided into: CON (vehicle, VCD (160 mg/kg; 15d, or OVX (ovariectomized. Lumbar BMD was monitored by DXA and μCT used to assess vertebral microarchitecture. BMD was not different between VCD and CON at any time point but was lower (P<.05 than baseline, starting 1 month after ovarian failure in VCD and OVX mice. Following μCT analysis there were no differences between CON and VCD, but OVX mice had lower bone volume fraction, trabecular thickness, and a trend for decreased connectivity density. These findings provide evidence that retention of residual ovarian tissue may protect aged follicle-depleted mice from accelerated bone loss to a lesser extent than that observed in young mice.

Examination of various postulates of irreversibility

Energy Technology Data Exchange (ETDEWEB)

Salmon, J [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)

1977-01-01

Firstly, it is shown that it is necessary to break the reversible character of the B.B.G.K.Y. system of equations by means of a postulate of irreversibility to obtain a kinetic equation compatible with the second principle of thermodynamics. Next, three postulates of irreversibility are examined: that of molecular chaos, that of linear relaxation and, finally, that of superposition. Then the corresponding kinetic equations and the expressions for the viscosity coefficient to which they lead are determined. Comparison with experiment is made each time. Lastly, an attempt to obtain an irreversible kinetic equation without introducing a postulate of irreversibility in the B.B.G.K.Y. system is realized. This consists in adding a complementary irreversible term to the fundamental equation of the dynamics of a particle. The suggested term is of quantum origin and leads to a kinetic equation of the Fokker-Planck type.

Impact of intra- and extra-osseous soft tissue composition on changes in bone mineral density with weight loss and regain.

Science.gov (United States)

Bosy-Westphal, Anja; Later, Wiebke; Schautz, Britta; Lagerpusch, Merit; Goele, Kristin; Heller, Martin; Glüer, Claus-C; Müller, Manfred J

2011-07-01

Recent studies report a significant gain in bone mineral density (BMD) after diet-induced weight loss. This might be explained by a measurement artefact. We therefore investigated the impact of intra- and extra-osseous soft tissue composition on bone measurements by dual X-ray absorptiometry (DXA) in a longitudinal study of diet-induced weight loss and regain in 55 women and 17 men (19-46 years, BMI 28.2-46.8 kg/m(2)). Total and regional BMD were measured before and after 12.7 ± 2.2 week diet-induced weight loss and 6 months after significant weight regain (≥30%). Hydration of fat free mass (FFM) was assessed by a 3-compartment model. Skeletal muscle (SM) mass, extra-osseous adipose tissue, and bone marrow were measured by whole body magnetic resonance imaging (MRI). Mean weight loss was -9.2 ± 4.4 kg (P BMAT) were not related to changes in BMD.

The Effect of Subcritical Bone Loss and Exposure on Recurrent Instability After Arthroscopic Bankart Repair in Intercollegiate American Football.

Science.gov (United States)

Dickens, Jonathan F; Owens, Brett D; Cameron, Kenneth L; DeBerardino, Thomas M; Masini, Brendan D; Peck, Karen Y; Svoboda, Steven J

2017-07-01

There is no consensus on the optimal method of stabilization (arthroscopic or open) in collision athletes with anterior shoulder instability. To examine the effect of "subcritical" bone loss and football-specific exposure on the rate of recurrent shoulder instability after arthroscopic stabilization in an intercollegiate American football population. Case-control study; Level of evidence, 3. Fifty intercollegiate football players underwent primary arthroscopic stabilization for anterior shoulder instability and returned to football for at least a single season. Preoperatively, 32 patients experienced recurrent subluxations, and 18 patients experienced a single or recurrent dislocation. Shoulders with glenoid bone loss >20%, an engaging Hill-Sachs lesion, an off-track lesion, and concomitant rotator cuff repair were excluded from the study. The primary outcome of interest was the ability to return to football without subsequent instability. Patients were followed for time to a subsequent instability event after return to play using days of exposure to football and total follow-up time after arthroscopic stabilization. Fifty consecutive patients returned to American football for a mean 1.5 seasons (range, 1-3) after arthroscopic stabilization. Three of 50 (6%; 95% CI, 1.3%-16.5%) patients experienced recurrent instability. There were no subsequent instability events after a mean 3.2 years of military service. All shoulders with glenoid bone loss >13.5% (n = 3) that underwent arthroscopic stabilization experienced recurrent instability upon returning to sport, while none of the shoulders with football ( X 2 = 15.80, P 13.5% glenoid bone loss had an incidence rate of 5.31 cases of recurrent instability per 1000 athlete-exposures of football. In 72,000 athlete-exposures to football with football players with <13.5% glenoid bone loss provides reliable outcomes and low recurrence rates.

Treatments to Prevent Bone Loss in Functional Hypothalamic Amenorrhea: A Systematic Review and Meta-Analysis

OpenAIRE

Altayar, Osama; Al Nofal, Alaa; Carranza Leon, B. Gisella; Prokop, Larry J.; Wang, Zhen; Murad, M. Hassan

2017-01-01

Objective: We conducted a systematic review and meta-analysis of studies that evaluated the effect of hormonal therapy [estrogen therapy including oral contraceptive pills (OCP)] and bisphosphonates in preventing bone loss in patients with functional hypothalamic amenorrhea (FHA). Methods: We searched several electronic databases for controlled and noncontrolled studies that enrolled females of any age presenting with FHA (including athletic, weight loss, and stress-associated amenorrhea/olig...

Polycythemia is associated with bone loss and reduced osteoblast activity in mice.

Science.gov (United States)

Oikonomidou, P R; Casu, C; Yang, Z; Crielaard, B; Shim, J H; Rivella, S; Vogiatzi, M G

2016-04-01

Increased fragility has been described in humans with polycythemia vera (PV). Herein, we describe an osteoporotic phenotype associated with decreased osteoblast activity in a mouse model of PV and another mouse of polycythemia and elevated circulating erythropoietin (EPO). Our results are important for patients with PV or those treated with recombinant EPO (rEPO). PV and other myeloproliferative syndromes have been recently associated with an increased risk for fractures. However, the presence of osteoporosis in these patients has not been well documented. EPO, a hormone primarily known to stimulate erythropoiesis, has been shown recently to regulate bone homeostasis in mice. The aim of this study was to examine the bone phenotype of a mouse model of PV and compare it to that of animals with polycythemia caused by elevated circulating EPO. Bone mass and remodeling were evaluated by micro-computed tomography and histomorphometry. The JAK2(V617F) knock-in mouse, a model of human PV, manifests polycythemia and low circulating EPO levels. Results from this mouse were compared to wild type (wt) controls and the tg6 transgenic mouse that shows polycythemia caused by increased constitutive expression of EPO. Compared to wt, both JAK2(V617F) and tg6 mice had a decrease in trabecular bone mass. Tg6 mice showed an additional modest decrease in cortical thickness and cortical bone volume per tissue volume (P Polycythemia caused by chronically elevated circulating EPO also results in bone loss, and implications on patients treated with rEPO should be evaluated.

The protective effect of Rhizoma Dioscoreae extract against alveolar bone loss in ovariectomized rats via regulating Wnt and p38 MAPK signaling.

Science.gov (United States)

Zhang, Zhiguo; Xiang, Lihua; Bai, Dong; Wang, Wenlai; Li, Yan; Pan, Jinghua; Liu, Hong; Wang, Shaojun; Xiao, Gary Guishan; Ju, Dahong

2014-12-12

The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with ovariectomy-induced bone loss. Female Wistar rats were subjected to either ovariectomy or a sham operation (SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX) or RDE by oral gavage or with 17β-estradiol (E2) subcutaneously. After treatments, the bone mineral density (BMD), the three-dimensional bone architecture of the alveolar bone and the plasma biomarkers of bone turnover were analyzed to assess bone metabolism, and the histomorphometry of the alveolar bone was observed. Microarrays were used to evaluate gene expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of genes was further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using real-time quantitative RT-PCR (qRT-PCR). Our results showed that RDE inhibited alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 207 genes and downregulated expression levels of 176 genes in the alveolar bone. The IPA showed that several genes had the potential to code for proteins that were involved in the Wnt/β-catenin signaling pathway (Wnt7a, Fzd2, Tcf3, Spp1, Frzb, Sfrp2 and Sfrp4) and the p38 MAPK signaling pathway (Il1rn and Mapk14). These experiments revealed that RDE could inhibit ovariectomy-induced alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may be involved in the reduced abnormal bone remodeling, which is associated with the modulation of the Wnt/β-catenin and the p38 MAPK signaling pathways via gene regulation.

Niclosamide suppresses RANKL-induced osteoclastogenesis and prevents LPS-induced bone loss

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Cheon, Yoon-Hee [Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kim, Ju-Young [Imaging Science-based Lung and Bone Diseases Research Center, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of); Baek, Jong Min; Ahn, Sung-Jun [Department of Anatomy, School of Medicine, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of); So, Hong-Seob, E-mail: jeanso@wku.ac.kr [Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of); Oh, Jaemin, E-mail: jmoh@wku.ac.kr [Imaging Science-based Lung and Bone Diseases Research Center, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of); Department of Anatomy, School of Medicine, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of); Institute for Skeletal Disease, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749 (Korea, Republic of)

2016-02-05

Niclosamide (5-chloro-salicyl-(2-chloro-4-nitro) anilide) is an oral anthelmintic drug used for treating intestinal infection of most tapeworms. Recently, niclosamide was shown to have considerable efficacy against some tumor cell lines, including colorectal, prostate, and breast cancers, and acute myelogenous leukemia. Specifically, the drug was identified as a potent inhibitor of signal transducer and activator of transcription 3 (STAT3), which is associated with osteoclast differentiation and function. In this study, we assessed the effect of niclosamide on osteoclastogenesis in vitro and in vivo. Our in vitro study showed that receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast differentiation was inhibited by niclosamide, due to inhibition of serine–threonine protein kinase (Akt) phosphorylation, inhibitor of nuclear factor-kappaB (IκB), and STAT3 serine{sup 727}. Niclosamide decreased the expression of the major transcription factors c-Fos and NFATc1, and thereafter abrogated the mRNA expression of osteoclast-specific genes, including TRAP, OSCAR, αv/β3 integrin (integrin αv, integrin β3), and cathepsin K (CtsK). In an in vivo model, niclosamide prevented lipopolysaccharide-induced bone loss by diminishing osteoclast activity. Taken together, our results show that niclosamide is effective in suppressing osteoclastogenesis and may be considered as a new and safe therapeutic candidate for the clinical treatment of osteoclast-related diseases such as osteoporosis. - Highlights: • We first investigated the anti-osteoclastogenic effects of niclosamide in vitro and in vivo. • Niclosamide impairs the activation of the Akt-IκB-STAT3 ser{sup 727} signaling axis. • Niclosamide acts a negative regulator of actin ring formation during osteoclast differentiation. • Niclosamide suppresses LPS-induced bone loss in vivo. • Niclosamide deserves new evaluation as a potential treatment target in various bone diseases.

BNNT-mediated irreversible electroporatio: its potential on cancer cells

Energy Technology Data Exchange (ETDEWEB)

Vittoria Raffa, Cristina Riggio, Michael W. Smith, Kevin C. Jordan, Wei Cao, Alfred Cuschieri

2012-10-01

Tissue ablation, i.e., the destruction of undesirable tissues, has become an important minimally invasive technique alternative to resection surgery for the treatment of tumours. Several methods for tissue ablation are based on thermal techniques using cold, e.g. cryosurgery [1] or heat, e.g. radiofrequency [2] or high-intensity focused ultrasound [3] or nanoparticle-mediated irradiation [4]. Alternatively, irreversible electroporation (IRE) has been proposed as non thermal technique for minimally invasive tissue ablation based on the use of electrical pulses. When the electric field is applied to a cell, a change in transmembrane potential is induced, which can cause biochemical and physiological changes of the cell. When the threshold value of the transmembrane potential is exceeded, the cell membrane becomes permeable, thus allowing entrance of molecules that otherwise cannot cross the membrane [5]. A further increase in the electric field intensity may cause irreversible membrane permeabilization and cell death. These pulses create irreversible defects (pores) in the cell membrane lipid bilayer, causing cell death through loss of cell homeostasis [6]. This is desirable in tumour ablation in order to produce large cell death, without the use of cytostatic drugs. A study of Davalos, Mir and Rubinsky showed that IRE can ablate substantial volumes of tissue without inducing a thermal effect and therefore serve as an independent and new tissue ablation modality; this opened the way to the use of IRE in surgery [7]. Their finding was subsequently confirmed in studies on cells [8], small animal models [9] and in large animal models in the liver [10] and the heart [11]. The most important finding in these papers is that irreversible electroporation produces precisely delineated ablation zones with cell scale resolution between ablated and non-ablated areas, without zones in which the extent of damage changes gradually as during thermal ablation. Furthermore, it is

Evaluation of marginal bone loss of dental implants with internal or external connections and its association with other variables: A systematic review.

Science.gov (United States)

de Medeiros, Rodrigo Antonio; Pellizzer, Eduardo Piza; Vechiato Filho, Aljomar José; Dos Santos, Daniela Micheline; da Silva, Emily Vivianne Freitas; Goiato, Marcelo Coelho

2016-10-01

Different factors can influence marginal bone loss around dental implants, including the type of internal and external connection between the implant and the abutment. The evidence needed to evaluate these factors is unclear. The purpose of this systematic review was to evaluate marginal bone loss by radiographic analysis around dental implants with internal or external connections. A systematic review was conducted following the criteria defined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Initially, a population, intervention, comparison, and outcome(s) (PICO) question was defined: does the connection type (internal or external) influence marginal bone loss in patients undergoing implantation? An electronic search of PubMed/MEDLINE and Scopus databases was performed for studies in English language published between January 2000 and December 2014 by 2 independent reviewers, who analyzed the marginal bone loss of dental implants with an internal and/or external connection. From an initial screening yield of 595 references and after considering inclusion and exclusion criteria, 17 articles were selected for this review. Among them, 10 studies compared groups of implants with internal and external connections; 1 study evaluated external connections; and 6 studies analyzed internal connections. A total of 2708 implants were placed in 864 patients. Regarding the connection type, 2347 implants had internal connections, and 361 implants had external connections. Most studies showed lower marginal bone loss values for internal connection implants than for external connection implants. Osseointegrated dental implants with internal connections exhibited lower marginal bone loss than implants with external connections. This finding is mainly the result of the platform switching concept, which is more frequently found in implants with internal connections. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry

Circumferential bone loss around splinted and nonsplinted immediately loaded implants retaining mandibular overdentures: A randomized controlled clinical trial using cone beam computed tomography.

Science.gov (United States)

Elsyad, Moustafa Abdou; Khirallah, Ahmed Samir

2016-11-01

Circumferential marginal bone around 2 splinted and nonsplinted immediately loaded implants in the edentulous mandible has not been previously investigated. The purpose of this randomized controlled clinical trial was to assess circumferential bone loss around splinted and nonsplinted immediately loaded implants retaining mandibular overdentures, using cone beam computed tomography (CBCT). Thirty participants with complete edentulism were allocated to 2 groups and received 2 implants in the canine region of the mandible. Implants were either left nonsplinted (with ball attachment [BA]) or splinted (with bar attachment [RA]). Mandibular overdentures were connected to the implants 1 week later. CBCT was used to evaluate vertical bone loss (VBL) and horizontal bone loss (HBLo) bone loss at the distal (D), buccal (B), mesial (M), and lingual (L) sites of each implant upon overdenture insertion (baseline, T0), 1 year (T1) and 3 years (T3) after insertion. Repeated measures ANOVA was used for statistical analysis (α=.05). No significant difference in the survival rate (93.3% for BA and 100% for RA) was found between groups (P=.156). VBL and HBLo increased significantly at T3 compared with T1 for both groups (Poverdentures were associated with significantly higher vertical and horizontal circumferential bone loss than those associated with splinted implants after a follow-up of 3 years. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Combined Effects of Phytoestrogen Genistein and Silicon on Ovariectomy-Induced Bone Loss in Rat.

Science.gov (United States)

Qi, Shanshan; Zheng, Hongxing

2017-06-01

This study was performed to evaluate the effect of concomitant supplementation of genistein and silicon on bone mineral density and bone metabolism-related markers in ovariectomized rat. Three-month-old Sprague Dawley female rats were subjected to bilateral ovariectomy (OVX) or sham surgery, and then the OVX rats were randomly divided into four groups: OVX-GEN, OVX-Si, OVX-GEN-Si, and OVX. Genistein and silicon supplementation was started immediately after OVX and continued for 10 weeks. In the OVX-GEN group, 5 mg genistein per gram body weight was injected subcutaneously. The OVX-Si group was given soluble silicon daily in demineralized water (Si 20 mg/kg body weight/day). The OVX-GEN-Si group was given subcutaneous injections of 5 mg genistein per gram body weight, at the same time, given soluble silicon daily (Si 20 mg/kg body weight/day). The results showed that the genistein supplementation in the OVX rats significantly prevented the loss of uterus weight; however, the silicon supplementation showed no effect on the uterus weight loss. The lumbar spine and femur bone mineral density was significantly decreased after OVX surgery; however, this decrease was inhibited by the genistein and/or silicon, and the BMD of the lumbar spine and femur was the highest in the OVX-GEN-Si-treated group. Histomorphometric analyses showed that the supplementation of genistein and/or silicon restored bone volume and trabecular thickness of femoral trabecular bone in the OVX group. Besides, the treatment with genistein and silicon for 10 weeks increased the serum levels of calcium and phosphorus in the OVX rats; serum calcium and serum phosphorus in the OVX-GEN-Si group were higher than those in the OVX-GEN and OVX-Si group (P silicon decreased serum alkaline phosphatase (ALP) and osteocalcin, which were increased by ovariectomy; serum ALP and osteocalcin in the OVX-GEN-Si group were lower than those in the OVX-GEN and OVX-Si groups (P silicon have synergistic effects on

High-impact exercise in rats prior to and during suspension can prevent bone loss

International Nuclear Information System (INIS)

Yanagihara, G.R.; Paiva, A.G.; Gasparini, G.A.; Macedo, A.P.; Frighetto, P.D.; Volpon, J.B.; Shimano, A.C.

2016-01-01

High-impact exercise has been considered an important method for treating bone loss in osteopenic experimental models. In this study, we investigated the effects of osteopenia caused by inactivity in femora and tibiae of rats subjected to jump training using the rat tail suspension model. Eight-week-old female Wistar rats were divided into five groups (n=10 each group): jump training for 2 weeks before suspension and training during 3 weeks of suspension; jump training for 2 weeks before suspension; jump training only during suspension; suspension without any training; and a control group. The exercise protocol consisted of 20 jumps/day, 5 days/week, with a jump height of 40 cm. The bone mineral density of the femora and tibiae was measured by double energy X-ray absorptiometry and the same bones were evaluated by mechanical tests. Bone microarchitecture was evaluated by scanning electron microscopy. One-way ANOVA was used to compare groups. Significance was determined as P<0.05. Regarding bone mineral density, mechanical properties and bone microarchitecture, the beneficial effects were greater in the bones of animals subjected to pre-suspension training and subsequently to training during suspension, compared with the bones of animals subjected to pre-suspension training or to training during suspension. Our results indicate that a period of high impact exercise prior to tail suspension in rats can prevent the installation of osteopenia if there is also training during the tail suspension

High-impact exercise in rats prior to and during suspension can prevent bone loss

Energy Technology Data Exchange (ETDEWEB)

Yanagihara, G.R.; Paiva, A.G.; Gasparini, G.A.; Macedo, A.P. [Laboratório de Bioengenharia, Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Frighetto, P.D. [Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, São Paulo, SP (Brazil); Volpon, J.B.; Shimano, A.C. [Laboratório de Bioengenharia, Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

2016-02-02

High-impact exercise has been considered an important method for treating bone loss in osteopenic experimental models. In this study, we investigated the effects of osteopenia caused by inactivity in femora and tibiae of rats subjected to jump training using the rat tail suspension model. Eight-week-old female Wistar rats were divided into five groups (n=10 each group): jump training for 2 weeks before suspension and training during 3 weeks of suspension; jump training for 2 weeks before suspension; jump training only during suspension; suspension without any training; and a control group. The exercise protocol consisted of 20 jumps/day, 5 days/week, with a jump height of 40 cm. The bone mineral density of the femora and tibiae was measured by double energy X-ray absorptiometry and the same bones were evaluated by mechanical tests. Bone microarchitecture was evaluated by scanning electron microscopy. One-way ANOVA was used to compare groups. Significance was determined as P<0.05. Regarding bone mineral density, mechanical properties and bone microarchitecture, the beneficial effects were greater in the bones of animals subjected to pre-suspension training and subsequently to training during suspension, compared with the bones of animals subjected to pre-suspension training or to training during suspension. Our results indicate that a period of high impact exercise prior to tail suspension in rats can prevent the installation of osteopenia if there is also training during the tail suspension.

Pharmacological study of the possible protective effect of certain natural products against irradiation-induced bone loss in female rats

International Nuclear Information System (INIS)

Elsabbagh, W.M.A.

2007-01-01

osteoporosis is a common human bone disease characterized by decreased bone mass and increased risk of fractures . it is associated with numerous risk factors; post menopausal oestrogen loss is the major factor. on another hand, exposure to γ -radiation may be responsible for the late reduction in bone mass following radiotherapy. research in nutrition suggests that diet can help to achieve optimal health specifically that human diet that contain macro nutrients and phytochemicals which have antioxidant and anti-inflammatory properties. the present study has been constructed to identify the effect of radiation exposure on bone, and to investigate the possible protective effect of garlic oil and parsley extract against bone loss induced in female virgin rats(180-200 g) either by ovariectomization or by exposure to γ -radiation. a pilot lest was carried first in this study on 2 groups of female virgin rats to estimate the degree of bone loss induced by exposure to fractionated doses of γ -radiation . the 1 st group's rats were normal non-irradiated and served as control normal group. in the 2 nd group, female rats were exposed to total dose of 15 Gy fractionated over 5 weeks (1 Gy 3 times weekly for 5 weeks), and measurements of urinary calcium and urinary hydroxyproline were carried out periodically after 4,8,11 and 15 weeks from the 1 st day of exposure to γ -radiation doses . the highest values were detected after 11 weeks i.e. after 6 weeks from the last exposure to γ -radiation

15-deoxy-δ12,14-prostaglandin j2 inhibits osteolytic breast cancer bone metastasis and estrogen deficiency-induced bone loss.

Directory of Open Access Journals (Sweden)

Ki Rim Kim

Full Text Available Breast cancer is the major cause of cancer death in women worldwide. The most common site of metastasis is bone. Bone metastases obstruct the normal bone remodeling process and aberrantly enhance osteoclast-mediated bone resorption, which results in osteolytic lesions. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2 is an endogenous ligand of peroxisome proliferator-activated receptor gamma (PPARγ that has anti-inflammatory and antitumor activity at micromolar concentrations through PPARγ-dependent and/or PPARγ-independent pathways. We investigated the inhibitory activity of 15d-PGJ2 on the bone loss that is associated with breast cancer bone metastasis and estrogen deficiency caused by cancer treatment. 15d-PGJ2 dose-dependently inhibited viability, migration, invasion, and parathyroid hormone-related protein (PTHrP production in MDA-MB-231 breast cancer cells. 15d-PGJ2 suppressed receptor activator of nuclear factor kappa-B ligand (RANKL mRNA levels and normalized osteoprotegerin (OPG mRNA levels in hFOB1.19 osteoblastic cells treated with culture medium from MDA-MB-231 cells or PTHrP, which decreased the RANKL/OPG ratio. 15d-PGJ2 blocked RANKL-induced osteoclastogenesis and inhibited the formation of resorption pits by decreasing the activities of cathepsin K and matrix metalloproteinases, which are secreted by mature osteoclasts. 15d-PGJ2 exerted its effects on breast cancer and bone cells via PPARγ-independent pathways. In Balb/c nu/nu mice that received an intracardiac injection of MDA-MB-231 cells, subcutaneously injected 15d-PGJ2 substantially decreased metastatic progression, cancer cell-mediated bone destruction in femora, tibiae, and mandibles, and serum PTHrP levels. 15d-PGJ2 prevented the destruction of femoral trabecular structures in estrogen-deprived ICR mice as measured by bone morphometric parameters and serum biochemical data. Therefore, 15d-PGJ2 may be beneficial for the prevention and treatment of breast cancer

Subcutaneous administration of insulin-like growth factor (IGF)-II/IGF binding protein-2 complex stimulates bone formation and prevents loss of bone mineral density in a rat model of disuse osteoporosis

Science.gov (United States)

Conover, Cheryl A.; Johnstone, Edward W.; Turner, Russell T.; Evans, Glenda L.; John Ballard, F. John; Doran, Patrick M.; Khosla, Sundeep

2002-01-01

Elevated serum levels of insulin-like growth factor binding protein-2 (IGFBP-2) and a precursor form of IGF-II are associated with marked increases in bone formation and skeletal mass in patients with hepatitis C-associated osteosclerosis. In vitro studies indicate that IGF-II in complex with IGFBP-2 has high affinity for bone matrix and is able to stimulate osteoblast proliferation. The purpose of this study was to determine the ability of the IGF-II/IGFBP-2 complex to increase bone mass in vivo. Osteopenia of the femur was induced by unilateral sciatic neurectomy in rats. At the time of surgery, 14-day osmotic minipumps containing vehicle or 2 microg IGF-II+9 microg IGFBP-2/100g body weight/day were implanted subcutaneously in the neck. Bone mineral density (BMD) measurements were taken the day of surgery and 14 days later using a PIXImus small animal densitometer. Neurectomy of the right hindlimb resulted in a 9% decrease in right femur BMD (P<0.05 vs. baseline). This loss in BMD was completely prevented by treatment with IGF-II/IGFBP-2. On the control limb, there was no loss of BMD over the 14 days and IGF-II/IGFBP-2 treatment resulted in a 9% increase in left femur BMD (P<0.05). Bone histomorphometry indicated increases in endocortical and cancellous bone formation rates and in trabecular thickness. These results demonstrate that short-term administration of the IGF-II/IGFBP-2 complex can prevent loss of BMD associated with disuse osteoporosis and stimulate bone formation in adult rats. Furthermore, they provide proof of concept for a novel anabolic approach to increasing bone mass in humans with osteoporosis.

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

Science.gov (United States)

Blaber, Elizabeth A.; Cheng-Campbell, Margareth A.; Almeida, Eduardo A. C.

2016-01-01

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31 decrease in bone volume ratio, a 14 decrease in trabecular thickness, and a 20 decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1. This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration

Hyperexcitability and cell loss in kainate-treated hippocampal slice cultures

DEFF Research Database (Denmark)

Benedikz, Eirikur; Casaccia-Bonnefil, P; Stelzer, A

1993-01-01

Loss of hippocampal interneurons has been reported in patients with severe temporal lobe epilepsy and in animals treated with kainate. We investigated the relationship between KA induced epileptiform discharge and loss of interneurons in hippocampal slice cultures. Application of KA (1 micro......M) produced reversible epileptiform discharge without neurotoxicity. KA (5 microM), in contrast, produced irreversible epileptiform discharge and neurotoxicity, suggesting that the irreversible epileptiform discharge was required for the neuronal loss. Loss of CA3 pyramidal cells and parvalbumin......-like immunoreactive (PV-I) interneurons preceded loss of somatostatin-like immunoreactive (SS-I) interneurons suggesting a different time course of KA neurotoxicity in these subpopulations of interneurons....

Micro-/nanoscaled irreversible Otto engine cycle with friction loss and boundary effects and its performance characteristics

International Nuclear Information System (INIS)

Nie, Wenjie; Liao, Qinghong; Zhang, ChunQiang; He, Jizhou

2010-01-01

An irreversible cycle model of the micro-/nanoscaled Otto engine cycle with internal friction loss is established. The general expressions of the work output and efficiency of the cycle are calculated based on the finite system thermodynamic theory, in which the quantum boundary effect of gas particles as working substance and the mechanical Casimir effect of gas system are considered. It is found that, for a micro-/nanoscaled Otto cycle devices, the work output W and efficiency η of the cycle can be expressed as the functions of the temperature ratio τ of the two heat reservoirs, the volume ratio r V and the surface area ratio r A of the two isochoric processes, the dimensionless thermal wavelength λ and other parameters of cycle, while for a macroscaled Otto cycle devices, the work output W 0 and efficiency η 0 of the cycle are independent of the surface area ratio r A and the dimensionless thermal wavelength λ. Further, the influence of boundary of cycle on the performance characteristics of the micro-/nanoscaled Otto cycle are analyzed in detail by introducing the output ratio W/W 0 and efficiency ratio η/η 0 . The results present the general performance characteristics of a micro-/nanoscaled Otto cycle and may serve as the basis for the design of a realistic Otto cycle device in micro-/nanoscale.

A selective androgen receptor modulator that reduces prostate tumor size and prevents orchidectomy-induced bone loss in rats.

Science.gov (United States)

Allan, George; Lai, Muh-Tsann; Sbriscia, Tifanie; Linton, Olivia; Haynes-Johnson, Donna; Bhattacharjee, Sheela; Dodds, Robert; Fiordeliso, James; Lanter, James; Sui, Zhihua; Lundeen, Scott

2007-01-01

The pharmacological activity of JNJ-26146900 is described. JNJ-26146900 is a nonsteroidal androgen receptor (AR) ligand with tissue-selective activity in rats. The compound was evaluated in in vitro and in vivo models of AR activity. It binds to the rat AR with a K(i) of 400nM and acts as a pure androgen antagonist in an in vitro cell-based assay. Its in vitro profile is similar to the androgen antagonist bicalutamide (Casodex). In intact rats, JNJ-26146900 reduces ventral prostate weight with an oral potency (ED(50)) of 20-30mg/kg, again comparable to that of bicalutamide. JNJ-26146900 prevented prostate tumor growth in the Dunning rat model, maximally inhibiting growth at a dose of 10mg/kg. It slowed tumor growth significantly in a CWR22-LD1 mouse xenograft model of human prostate cancer. It was tested in aged male rats for its ability to prevent bone loss and loss of lean body mass following orchidectomy. After 6 weeks of dosing, bone volume decreased by 33% in orchidectomized versus intact vehicle-treated rats with a probability (P) of less than 0.05, as measured by micro-computerized tomography analysis. At a dose of 30mg/kg, JNJ-26146900 significantly reduced castration-induced tibial bone loss as indicated by the following parameters: bone volume, trabecular connectivity, trabecular number and spacing between trabeculae. Bone mineral density decreased from 229+/-34mg/cm(3) of hydroxyapatite to 166+/-26mg/cm(3) following orchidectomy, and was maintained at 194+/-20mg/cm(3) with JNJ-26146900 treatment (Pselective androgen receptor modulators (SARMs) have the potential for anabolic effects on bone and muscle while maintaining therapeutic efficacy in prostate cancer.

Parametric analysis of an irreversible proton exchange membrane fuel cell/absorption refrigerator hybrid system

International Nuclear Information System (INIS)

Yang, Puqing; Zhang, Houcheng

2015-01-01

A hybrid system mainly consisting of a PEMFC (proton exchange membrane fuel cell) and an absorption refrigerator is proposed, where the PEMFC directly converts the chemical energy contained in the hydrogen into electrical and thermal energies, and the thermal energy is transferred to drive the bottoming absorption refrigerator for cooling purpose. By considering the existing irreversible losses in the hybrid system, the operating current density region of the PEMFC permits the absorption refrigerator to exert its function is determined and the analytical expressions for the equivalent power output and efficiency of the hybrid system under different operating conditions are specified. Numerical calculations show that the equivalent maximum power density and the corresponding efficiency of the hybrid system can be respectively increased by 5.3% and 6.8% compared to that of the stand-alone PEMFC. Comprehensive parametric analyses are conducted to reveal the effects of the internal irreversibility of the absorption refrigerator, operating current density, operating temperature and operating pressure of the PEMFC, and some integrated parameters related to the thermodynamic losses on the performance of the hybrid system. The model presented in the paper is more general than previous study, and the results for some special cases can be directly derived from this paper. - Highlights: • A CHP system composed of a PEMFC and an absorption refrigerator is proposed. • Current density region enables the absorption refrigerator to work is determined. • Multiple irreversible losses in the system are analytically characterized. • Maximum power density and corresponding efficiency can be increased by 5.3% and 6.8%. • Effects of some designing and operating parameters on the performance are discussed

Damping ratio analysis of tooth stability under various simulated degrees of vertical alveolar bone loss and different root types.

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Ho, Kuo-Ning; Lee, Sheng-Yang; Huang, Haw-Ming

2017-08-03

The purpose of this study was to evaluate the feasibility of using damping ratio (DR) analysis combined with resonance frequency (RF) and periotest (PTV) analyses to provide additional information about natural tooth stability under various simulated degrees of alveolar vertical bone loss and various root types. Three experimental tooth models, including upper central incisor, upper first premolar, and upper first molar were fabricated using Ti6Al4V alloy. In the tooth models, the periodontal ligament and alveolar bone were simulated using a soft lining material and gypsum, respectively. Various degrees of vertical bone loss were simulated by decreasing the surrounding bone level apically from the cementoenamel junction in 2-mm steps incrementally downward for 10 mm. A commercially available RF analyzer was used to measure the RF and DR of impulse-forced vibrations on the tooth models. The results showed that DRs increased as alveolar vertical bone height decreased and had high coefficients of determination in the linear regression analysis. The damping ratio of the central incisor model without a simulated periodontal ligament were 11.95 ± 1.92 and 27.50 ± 0.67% respectively when their bone levels were set at 2 and 10 mm apically from the cementoenamel junction. These values significantly changed to 28.85 ± 2.54% (p = 0.000) and 51.25 ± 4.78% (p = 0.003) when the tooth model was covered with simulated periodontal ligament. Moreover, teeth with different root types showed different DR and RF patterns. Teeth with multiple roots had lower DRs than teeth with single roots. Damping ratio analysis combined with PTV and RF analysis provides more useful information on the assessment of changes in vertical alveolar bone loss than PTV or RF analysis alone.

RECOVERY OF BONE MINERAL DENSITY AND FERTILITY IN A FORMER AMENORRHEIC ATHLETE

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Karen Hind

2008-09-01

Full Text Available Inadequate dietary intake and prolonged amenorrhea in women athletes can lead to bone loss, particularly at the spine, which may be irreversible. This report presents the case of a woman endurance runner, followed prospectively over 6 years after presenting with the female athlete triad. Bone mineral density (BMD and body composition were assessed by dual-energy X-ray absorptiometry. At baseline, lumbar spine (LS, total hip and total body (TB BMD Z-scores were -2.2, -0.5 and -0.3 respectively. At 6 years, following a recovery plan of cognitive behavioural therapy (CBT, weight gain, improved dietary intake and reduced training load, the athlete regained menstrual function and BMD. LS, TB and hip BMD Z-scores improved to -0.6, -0.1 and 0.1 respectively. Restoration of fertility was indicated by pregnancy, following only 4 months of regular menstruation. This case report suggests that bone density and fertility may not be completely jeopardised in formerly amenorrheic and osteopenic athletes, providing recovery through diet, weight gain, and return of menstruation is achieved within the third decade. Longitudinal studies tracking bone changes in women with amenorrhea and low BMD are required and would have important implications for the treatment of the female athlete triad

Pomegranate Peel Extract Prevents Bone Loss in a Preclinical Model of Osteoporosis and Stimulates Osteoblastic Differentiation in Vitro

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Mélanie Spilmont

2015-11-01

Full Text Available The nutritional benefits of pomegranate have attracted great scientific interest. The pomegranate, including the pomegranate peel, has been used worldwide for many years as a fruit with medicinal activity, mostly antioxidant properties. Among chronic diseases, osteoporosis, which is associated with bone remodelling impairment leading to progressive bone loss, could eventually benefit from antioxidant compounds because of the involvement of oxidative stress in the pathogenesis of osteopenia. In this study, with in vivo and ex vivo experiments, we investigated whether the consumption of pomegranate peel extract (PGPE could limit the process of osteopenia. We demonstrated that in ovariectomized (OVX C57BL/6J mice, PGPE consumption was able to significantly prevent the decrease in bone mineral density (−31.9%; p < 0.001 vs. OVX mice and bone microarchitecture impairment. Moreover, the exposure of RAW264.7 cells to serum harvested from mice that had been given a PGPE-enriched diet elicited reduced osteoclast differentiation and bone resorption, as shown by the inhibition of the major osteoclast markers. In addition, PGPE appeared to substantially stimulate osteoblastic MC3T3-E1 alkaline phosphatase (ALP activity at day 7, mineralization at day 21 and the transcription level of osteogenic markers. PGPE may be effective in preventing the bone loss associated with ovariectomy in mice, and offers a promising alternative for the nutritional management of this disease.

Pomegranate Peel Extract Prevents Bone Loss in a Preclinical Model of Osteoporosis and Stimulates Osteoblastic Differentiation in Vitro.

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Spilmont, Mélanie; Léotoing, Laurent; Davicco, Marie-Jeanne; Lebecque, Patrice; Miot-Noirault, Elisabeth; Pilet, Paul; Rios, Laurent; Wittrant, Yohann; Coxam, Véronique

2015-11-11

The nutritional benefits of pomegranate have attracted great scientific interest. The pomegranate, including the pomegranate peel, has been used worldwide for many years as a fruit with medicinal activity, mostly antioxidant properties. Among chronic diseases, osteoporosis, which is associated with bone remodelling impairment leading to progressive bone loss, could eventually benefit from antioxidant compounds because of the involvement of oxidative stress in the pathogenesis of osteopenia. In this study, with in vivo and ex vivo experiments, we investigated whether the consumption of pomegranate peel extract (PGPE) could limit the process of osteopenia. We demonstrated that in ovariectomized (OVX) C57BL/6J mice, PGPE consumption was able to significantly prevent the decrease in bone mineral density (-31.9%; p < 0.001 vs. OVX mice) and bone microarchitecture impairment. Moreover, the exposure of RAW264.7 cells to serum harvested from mice that had been given a PGPE-enriched diet elicited reduced osteoclast differentiation and bone resorption, as shown by the inhibition of the major osteoclast markers. In addition, PGPE appeared to substantially stimulate osteoblastic MC3T3-E1 alkaline phosphatase (ALP) activity at day 7, mineralization at day 21 and the transcription level of osteogenic markers. PGPE may be effective in preventing the bone loss associated with ovariectomy in mice, and offers a promising alternative for the nutritional management of this disease.

Marginal bone loss evaluation around immediate non-occlusal microthreaded implants placed in fresh extraction sockets in the maxilla: a 3-year study.

Science.gov (United States)

Calvo-Guirado, José L; Gómez-Moreno, Gerardo; Aguilar-Salvatierra, Antonio; Guardia, Javier; Delgado-Ruiz, Rafael A; Romanos, Georgios E

2015-07-01

To evaluate marginal bone loss over 3 years around immediate microthreaded implants placed in the maxillary anterior/esthetic zone and immediately restored with single crowns. Seventy-one implants (with microthreads up to the platform--rough surface body and neck, internal connection and platform switching) were placed in fresh extraction sockets in the maxillary arches of 30 men and 23 women (mean age 37.85 ± 7.09 years, range 27-60). All subjects had at least 3 mm of soft tissue to allow the establishment of adequate biologic width and to reduce bone resorption. Each patient received a provisional restoration immediately after implant placement with slight occlusal contact. Mesial and distal bone height was evaluated using digital radiography on the day following implant placement (baseline) and after 1, 2, and 3 years. Primary stability was measured with resonance frequency analysis. No implants failed, resulting in a cumulative survival rate of 100% after 3 years. Marginal bone loss from implant collar to bone crest measured at baseline (peri-implant bone defect at the fresh extraction socket) and after 3 years was 0.86 mm ± 0.29 mm. Mesial and distal site crestal bone loss ranged from 3.42 mm ± 1.2 mm at baseline to 3.51 mm ± 1.5 mm after 3 years (P = 0.063) and from 3.38 mm ± 0.9 mm at baseline to 3.49 mm ± 0.9 mm after 3 years, respectively (P = 0.086). This prospective study found minimal marginal bone loss and a 100% implant survival rate over the 3-year follow-up for microthreaded immediate implants subjected to immediate non-occlusal loading. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[A temporal bone CT study of the infants with hearing loss referred from universal newborn hearing screening].

Science.gov (United States)

Tao, Zheng; Li, Yun; Hou, Zheng; Cheng, Lan

2007-02-01

To explore the high resolution CT image of temporal bone in infants with hearing loss, and its value in evaluating the cause of hearing loss. In 2005, 0.12 million newborns have been included in the hearing screening system in Shanghai, and 1077 infants have failed to pass the hearing screening. One hundred and eight four infants were diagnosed as congenital hearing loss from mild to profound. A temporal bone HRCT scanning was performed to these infants. Among the 184 patients with congenital hearing loss, HRCT showed that 26 cases (14.1%) were associated with external ear malformation, and 21 cases (11.4%) were associated with middle ear malformation, 31 cases (16.8%) associated with inner ear malformation. The patients with inner ear malformation included 12 cases with Mondini malformation, 1 case with common cavity malformation, 6 cases with large vestibule malformation, 5 cases with internal auditory canal abnormalities, and 10 cases with vestibule, semicircular canals abnormalities. In addition, there were 20 cases (10.8%) with fluid in middle ear. HRCT image play an important role in the differential diagnosis and treatment of infants with congenital hearing loss.

Dietary emu oil supplementation suppresses 5-fluorouracil chemotherapy-induced inflammation, osteoclast formation, and bone loss.

Science.gov (United States)

Raghu Nadhanan, Rethi; Abimosleh, Suzanne M; Su, Yu-Wen; Scherer, Michaela A; Howarth, Gordon S; Xian, Cory J

2012-06-01

Cancer chemotherapy can cause osteopenia or osteoporosis, and yet the underlying mechanisms remain unclear, and currently, no preventative treatments are available. This study investigated damaging effects of 5-fluorouracil (5-FU) on histological, cellular, and molecular changes in the tibial metaphysis and potential protective benefits of emu oil (EO), which is known to possess a potent anti-inflammatory property. Female dark agouti rats were gavaged orally with EO or water (1 ml·day(-1)·rat(-1)) for 1 wk before a single ip injection of 5-FU (150 mg/kg) or saline (Sal) was given. The treatment groups were H(2)O + Sal, H(2)O + 5-FU, EO + 5-FU, and EO + Sal. Oral gavage was given throughout the whole period up to 1 day before euthanasia (days 3, 4, and 5 post-5-FU). Histological analysis showed that H(2)O + 5-FU significantly reduced heights of primary spongiosa on days 3 and 5 and trabecular bone volume of secondary spongiosa on days 3 and 4. It reduced density of osteoblasts slightly and caused an increase in the density of osteoclasts on trabecular bone surface on day 4. EO supplementation prevented reduction of osteoblasts and induction of osteoclasts and bone loss caused by 5-FU. Gene expression studies confirmed an inhibitory effect of EO on osteoclasts since it suppressed 5-FU-induced expression of proinflammatory and osteoclastogenic cytokine TNFα, osteoclast marker receptor activator of nuclear factor-κB, and osteoclast-associated receptor. Therefore, this study demonstrated that EO can counter 5-FU chemotherapy-induced inflammation in bone, preserve osteoblasts, suppress osteoclast formation, and potentially be useful in preventing 5-FU chemotherapy-induced bone loss.

Aerobic Exercise and Whole-Body Vibration in Offsetting Bone Loss in Older Adults

Directory of Open Access Journals (Sweden)

Pei-Yang Liu

2011-01-01

Full Text Available Osteoporosis and its associated fractures are common complications of aging and most strategies to prevent and/or treat bone loss focused on antiresorptive medications. However, aerobic exercise (AEX and/or whole-body vibration (WBV might have beneficial effect on bone mass and provide an alternative approach to increase or maintain bone mineral density (BMD and reduce the risk of fractures. The purpose of this paper was to investigate the potential benefits of AEX and WBV on BMD in older population and discuss the possible mechanisms of action. Several online databases were utilized and based on the available literature the consensus is that both AEX and WBV may increase spine and femoral BMD in older adults. Therefore, AEX and WBV could serve as nonpharmacological and complementary approaches to increasing/maintaining BMD. However, it is uncertain if noted effects could be permanent and further studies are needed to investigate sustainability of either type of the exercise.

Peri-Implant Distribution of Polyethylene Debris in Postmortem-Retrieved Knee Arthroplasties: Can Polyethylene Debris Explain Loss of Cement-Bone Interlock in Successful Total Knee Arthroplasties?

Science.gov (United States)

Cyndari, Karen I; Goodheart, Jacklyn R; Miller, Mark A; Oest, Megan E; Damron, Timothy A; Mann, Kenneth A

2017-07-01

Loss of mechanical interlock between cement and bone with in vivo service has been recently quantified for functioning, nonrevised, cemented total knee arthroplasties (TKAs). The cause of interlocking trabecular resorption is not known. The goal of this study is to quantify the distribution of PE debris at the cement-bone interface and determine if polyethylene (PE) debris is locally associated with loss of interlock. Fresh, nonrevised, postmortem-retrieved TKAs (n = 8) were obtained en bloc. Laboratory-prepared constructs (n = 2) served as negative controls. The intact cement-bone interface of each proximal tibia was embedded in Spurr's resin, sectioned, and imaged under polarized light to identify birefringent PE particles. PE wear particle number density was quantified at the cement-bone interface and distal to the interface, and then compared with local loss of cement-bone interlock. The average PE particle number density for postmortem-retrieved TKAs ranged from 8.6 (1.3) to 24.9 (3.1) particles/mm 2 (standard error) but was weakly correlated with years in service. The average particle number density was twice as high as distal (>5mm) to the interface compared to at the interface. The local loss of interlock at the interface was not related to the presence, absence, or particle density of PE. PE debris can migrate extensively along the cement-bone interface of well-fixed tibial components. However, the amount of local bone loss at the cement-bone interface was not correlated with the amount of PE debris at the interface, suggesting that the observed loss of trabecular interlock in these well-fixed TKAs may be due to alternative factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of Audiological Results Between a Transcutaneous and a Percutaneous Bone Conduction Instrument in Conductive Hearing Loss.

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Gerdes, Timo; Salcher, Rolf Benedikt; Schwab, Burkard; Lenarz, Thomas; Maier, Hannes

2016-07-01

In conductive, mixed hearing losses and single-sided-deafness bone-anchored hearing aids are a well-established treatment. The transcutaneous transmission across the intact skin avoids the percutaneous abutment of a bone-anchored device with the usual risk of infections and requires less care.In this study, the audiological results of the Bonebridge transcutaneous bone conduction implant (MED-EL) are compared to the generally used percutaneous device BP100 (Cochlear Ltd., Sydney, Australia). Ten patients implanted with the transcutaneous hearing implant were compared to 10 matched patients implanted with a percutaneous device. Tests included pure-tone AC and BC thresholds and unaided and aided sound field thresholds. Speech intelligibility was determined in quiet using the Freiburg monosyllable test and in noise with the Oldenburg sentence test (OLSA) in sound field with speech from the front (S0). The subjective benefit was assessed with the Abbreviated Profile of Hearing Aid Benefit. In comparison with the unaided condition there was a significant improvement in aided thresholds, word recognition scores (WRS), and speech reception thresholds (SRT) in noise, measured in sound field, for both devices. The comparison of the two devices revealed a minor but not significant difference in functional gain (Bonebridge: PTA = 27.5 dB [mean]; BAHA: PTA = 26.3 dB [mean]). No significant difference between the two devices was found when comparing the improvement in WRSs and SRTs (Bonebridge: improvement WRS = 80% [median], improvement SRT = 6.5 dB SNR [median]; BAHA: improvement WRS = 77.5% [median], BAHA: improvement SRT = 6.9 dB SNR [median]). Our data show that the transcutaneous bone conduction hearing implant is an audiologically equivalent alternative to percutaneous bone-anchored devices in conductive hearing loss with a minor sensorineural hearing loss component.

Crestal bone loss around submerged and nonsubmerged dental implants: A systematic review.

Science.gov (United States)

Al Amri, Mohammad D

2016-05-01

To my knowledge, there is no systematic review of crestal bone loss (CBL) around submerged and nonsubmerged dental implants. The purpose of this review was to systematically assess CBL around submerged and nonsubmerged dental implants. The addressed focused question was, "Does crestal and subcrestal placement of dental implants influence crestal bone levels?" Databases were searched from 1986 through October 2015 using different combinations of the following keywords: crestal, sub-crestal, bone loss, dental implant, submerged, and nonsubmerged. Reference lists of potentially relevant original and review articles were hand-searched to identify any further studies. Letters to the editor, case reports, commentaries, studies on platform-switched implants, and studies published in languages other than English were excluded. In total, 13 studies (6 human and 7 animal), which were performed at universities, were included. In the human studies, the number of participants ranged from 8 to 84 individuals. The follow-up period ranged from 1 to 5 years. CBL at the test sites ranged from 0.17 mm to 0.9 mm and at control sites from 0.02 mm to 1.4 mm. Five human studies reported no significant difference in CBL around implants placed at the test and control sites. All animal studies were performed in dogs with a mean age ranging from 1 to approximately 2 years. The follow-up period ranged from 2 to 6 months. Four animal studies reported no significant difference in CBL around submerged and nonsubmerged implants. No significant difference in CBL was found around submerged and nonsubmerged dental implants. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Biophotonics and Bone Biology

Science.gov (United States)

Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

2004-01-01

One of the more-serious side effects of extended space flight is an accelerated bone loss [Bioastronautics Critical Path Roadmap, http://research.hq.nasa.gov/code_u/bcpr/index.cfm]. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It shows that an extrapolation of the microgravity induced bone loss rates to longer time scales, such as a 2.5 year round-trip to Mars (6 months out at 0 g, 1.5 year stay on Mars at 0.38 g, 6 months back at 0 g), could severely compromise the skeletal system of such a person.

Retrograde nail for tibiotalocalcaneal arthrodesis as a limb salvage procedure for open distal tibia and talus fractures with severe bone loss.

Science.gov (United States)

Ochman, Sabine; Evers, Julia; Raschke, Michael J; Vordemvenne, Thomas

2012-01-01

The treatment of complex fractures of the distal tibia, ankle, and talus with soft tissue damage, bone loss, and nonreconstructable joints for which the optimal timing for reduction and fixation has been missed is challenging. In such cases primary arthrodesis might be a treatment option. We report a series of multi-injured patients with severe soft tissue damage and bone loss, who were treated with a retrograde tibiotalocalcaneal arthrodesis nail as a minimally invasive treatment option for limb salvage. After a median follow-up of 5.4 years, all patients returned to their former profession. The ankle and bone fusion was complete, with moderate functional results and quality of life. Calcaneotibial arthrodesis using a retrograde nail is a good treatment option for nonreconstructable fractures of the ankle joint with severe bone loss and poor soft tissue quality in selected patients with multiple injuries, in particular, those involving both lower extremities, as a salvage procedure. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Atrophic femoral nonunion with bone loss: treatment with monorail transport: a case report.

Science.gov (United States)

Gay, David M; Voss, Frank R

2004-08-01

Nonunions are an uncommon outcome of femoral fractures. Atrophic nonunions with a leg length discrepancy secondary to bone loss are often the most difficult to treat, and the treatment options are limited. We present a case that uses concomitant monolateral external fixation and intramedullary nailing to heal a nonunion and perform a simultaneous 7-cm lengthening procedure in a 33-year-old female.

Hearing Loss due to Carbon Monoxide Poisoning

DEFF Research Database (Denmark)

Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

2013-01-01

Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker a...

High-frequency, low-magnitude vibration does not prevent bone loss resulting from muscle disuse in mice following botulinum toxin injection.

Science.gov (United States)

Manske, Sarah L; Good, Craig A; Zernicke, Ronald F; Boyd, Steven K

2012-01-01

High-frequency, low-magnitude vibration enhances bone formation ostensibly by mimicking normal postural muscle activity. We tested this hypothesis by examining whether daily exposure to low-magnitude vibration (VIB) would maintain bone in a muscle disuse model with botulinum toxin type A (BTX). Female 16-18 wk old BALB/c mice (N = 36) were assigned to BTX-VIB, BTX-SHAM, VIB, or SHAM. BTX mice were injected with BTX (20 µL; 1 U/100 g body mass) into the left hindlimb posterior musculature. All mice were anaesthetized for 20 min/d, 5 d/wk, for 3 wk, and the left leg mounted to a holder. Through the holder, VIB mice received 45 Hz, ± 0.6 g sinusoidal acceleration without weight bearing. SHAM mice received no vibration. At baseline and 3 wk, muscle cross-sectional area (MCSA) and tibial bone properties (epiphysis, metaphysis and diaphysis) were assessed by in vivo micro-CT. Bone volume fraction in the metaphysis decreased 12 ± 9% and 7 ± 6% in BTX-VIB and BTX-SHAM, but increased in the VIB and SHAM. There were no differences in dynamic histomorphometry outcomes between BTX-VIB and BTX nor between VIB and SHAM. Thus, vibration did not prevent bone loss induced by a rapid decline in muscle activity nor produce an anabolic effect in normal mice. The daily loading duration was shorter than would be expected from postural muscle activity, and may have been insufficient to prevent bone loss. Based on the approach used in this study, vibration does not prevent bone loss in the absence of muscle activity induced by BTX.

High-frequency, low-magnitude vibration does not prevent bone loss resulting from muscle disuse in mice following botulinum toxin injection.

Directory of Open Access Journals (Sweden)

Sarah L Manske

Full Text Available High-frequency, low-magnitude vibration enhances bone formation ostensibly by mimicking normal postural muscle activity. We tested this hypothesis by examining whether daily exposure to low-magnitude vibration (VIB would maintain bone in a muscle disuse model with botulinum toxin type A (BTX. Female 16-18 wk old BALB/c mice (N = 36 were assigned to BTX-VIB, BTX-SHAM, VIB, or SHAM. BTX mice were injected with BTX (20 µL; 1 U/100 g body mass into the left hindlimb posterior musculature. All mice were anaesthetized for 20 min/d, 5 d/wk, for 3 wk, and the left leg mounted to a holder. Through the holder, VIB mice received 45 Hz, ± 0.6 g sinusoidal acceleration without weight bearing. SHAM mice received no vibration. At baseline and 3 wk, muscle cross-sectional area (MCSA and tibial bone properties (epiphysis, metaphysis and diaphysis were assessed by in vivo micro-CT. Bone volume fraction in the metaphysis decreased 12 ± 9% and 7 ± 6% in BTX-VIB and BTX-SHAM, but increased in the VIB and SHAM. There were no differences in dynamic histomorphometry outcomes between BTX-VIB and BTX nor between VIB and SHAM. Thus, vibration did not prevent bone loss induced by a rapid decline in muscle activity nor produce an anabolic effect in normal mice. The daily loading duration was shorter than would be expected from postural muscle activity, and may have been insufficient to prevent bone loss. Based on the approach used in this study, vibration does not prevent bone loss in the absence of muscle activity induced by BTX.

Short-term, daily exposure to cold temperature may be an efficient way to prevent muscle atrophy and bone loss in a microgravity environment

Science.gov (United States)

Deng, Claudia; Wang, Ping; Zhang, Xiangming; Wang, Ya

2015-04-01

Microgravity induces less pressure on muscle/bone, which is a major reason for muscle atrophy as well as bone loss. Currently, physical exercise is the only countermeasure used consistently in the U.S. human space program to counteract the microgravity-induced skeletal muscle atrophy and bone loss. However, the routinely almost daily time commitment is significant and represents a potential risk to the accomplishment of other mission operational tasks. Therefore, development of more efficient exercise programs (with less time) to prevent astronauts from muscle atrophy and bone loss are needed. Consider the two types of muscle contraction: exercising forces muscle contraction and prevents microgravity-induced muscle atrophy/bone loss, which is a voluntary response through the motor nervous system; and cold temperature exposure-induced muscle contraction is an involuntary response through the vegetative nervous system, we formed a new hypothesis. The main purpose of this pilot study was to test our hypothesis that exercise at 4 °C is more efficient than at room temperature to prevent microgravity-induced muscle atrophy/bone loss and, consequently reduces physical exercise time. Twenty mice were divided into two groups with or without daily short-term (10 min × 2, at 12 h interval) cold temperature (4 °C) exposure for 30 days. The whole bodyweight, muscle strength and bone density were measured after terminating the experiments. The results from the one-month pilot study support our hypothesis and suggest that it would be reasonable to use more mice, in a microgravity environment and observe for a longer period to obtain a conclusion. We believe that the results from such a study will help to develop efficient exercise, which will finally benefit astronauts' heath and NASA's missions.

Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats

DEFF Research Database (Denmark)

Grubbe, M-C; Thomsen, Jesper Skovhus; Nyengaard, J R

2014-01-01

Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind...... of periosteal BFR/BS (2-fold increase vs. BTX, Pmuscle mass (+29% vs. BTX, Pmuscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse......BMD, -13%, Pmuscle mass (-69%, Pmuscle cell cross sectional area (CSA) (-73%, P

Repeated oral administration of a cathepsin K inhibitor significantly suppresses bone resorption in exercising horses with evidence of increased bone formation and maintained bone turnover.

Science.gov (United States)

Hussein, H; Dulin, J; Smanik, L; Drost, W T; Russell, D; Wellman, M; Bertone, A

2017-08-01

Our investigations evaluated the effect of VEL-0230, a highly specific irreversible inhibitor of cathepsin K (CatK). The objectives of our study were to determine whether repeated dosing of a CatK inhibitor (CatKI) produced a desired inhibition of the bone resorption biomarker (CTX-1), and document the effect of repeated dosing on bone homeostasis, structure, and dynamics of bone resorption and formation in horses. Twelve young exercising horses were randomized in a prospective, controlled clinical trial and received 4 weekly doses of a CatKI or vehicle. Baseline and poststudy nuclear scintigraphy, blood sampling and analysis of plasma bone biomarkers (CTX-1 and osteocalcin), poststudy bone fluorescent labeling, and bone biopsy were performed. Bone specimens were further processed for microcomputed tomography and bone histomorphometry. Each dose of this CatKI transiently inhibited plasma CTX-1 (reflecting inhibition of bone collagen resorption) and increased bone plasma osteocalcin concentrations, with no detectable adverse effect on normal bone turnover in the face of exercise. Bone morphology, density, and formation rate were not different between control and treated group. Further investigation of CatK inhibition in abnormal bone turnover is required in animals with bone diseases. © 2016 John Wiley & Sons Ltd.

Severe Bone Loss induced by Orthodontic Elastic Separator: A Rare Case Report

OpenAIRE

A E Vishwanath; B K Sharmada; Sandesh S Pai; Nandini Nelvigi

2013-01-01

A displaced orthodontic elastic separator was proposed as being the source of a gingival abscess that progressed to severe bone loss and exfoliation in a healthy adolescent patient with sound periodontal status prior to commencement of orthodontic treatment. After 1 year of undergoing orthodontic treatment, the patient presented with dull pain and mobility in the left upper permanent molar for which there was no apparent etiology. On clinical examination, the patient had gingival inflammation...

Entropy, Extropy and the Physical Driver of Irreversibility

Directory of Open Access Journals (Sweden)

Attila Grandpierre

2012-06-01

Full Text Available We point out that the fundamental irreversibility of Nature requires the introduction of a suitable measure for the distance from equilibrium. We show that entropy, which is widely held to be such a measure, suffers from the problem that it does not have a physical meaning, since it is introduced on the basis of mathematical arguments. As a consequence, the basic physics beyond irreversibility has remained obscure. We present here a simple but transparent physical approach for solving the problem of irreversibility. This approach shows that extropy, the fundamental thermodynamic variable introduced by Katalin Martinás, is the suitable measure for the distance from equilibrium, since it corresponds to the actual driver of irreversible processes. Since extropy explicitly contains in its definition all the general thermodynamic forces that drive irreversible processes, extropy is the suitable physical measure of irreversibility.

Prevention of aromatase inhibitor-induced bone loss with alendronate in postmenopausal women: The BATMAN Trial.

Science.gov (United States)

Lomax, Anna J; Yee Yap, Saw; White, Karen; Beith, Jane; Abdi, Ehtesham; Broad, Adam; Sewak, Sanjeev; Lee, Chooi; Sambrook, Philip; Pocock, Nicholas; Henry, Margaret J; Yeow, Elaine G; Bell, Richard

2013-12-01

Postmenopausal women on aromatase inhibitors (AI) are at risk of aromatase inhibitor-associated bone loss (AIBL) and fractures. In 2005 Osteoporosis Australia proposed an algorithm for bisphosphonate intervention. Three hundred and three postmenopausal women with early breast cancer (EBC) were enrolled (osteoporotic, n=25; osteopaenic, n=146; normal bone mineral density (BMD), n=126). Weekly alendronate (70 mg) treatment efficacy as triggered by the algorithm in preventing bone loss was evaluated. All patients received anastrozole (1 mg daily), calcium and vitamin D. All osteoporotic patients received alendronate at baseline. Eleven out of the 146 (7.5%) osteopaenic patients commenced alendronate within 18 months of participation and eleven commenced after. One hundred and twenty four out of the 146 (84.9%) osteopaenic patients and all 126 with normal baseline BMD did not trigger the algorithm. At three years, lumbar spine mean BMD increased (15.6%, p<0.01) in the osteoporotic group. BMD in the osteopaenic group with early intervention significantly increased at three years (6.3%, p=0.02). No significant change was seen in the late intervention group. No change was observed in those with osteopaenia without alendronate. There was a significant drop in lumbar spine (-5.4%) and hip (-4.5%) mean BMD, in the normal BMD group, none of whom received alendronate. Fracture data will be presented. In postmenopausal women with endocrine-responsive EBC, BMD improved over time when a bisphosphonate is administered with anastrozole in osteoporotic patients using an osteoporosis schedule. Subjects with normal baseline BMD experienced the greatest BMD loss, although none became osteoporotic.

Premature loss of bone remodeling compartment canopies is associated with deficient bone formation

DEFF Research Database (Denmark)

Jensen, Pia Rosgaard; Andersen, Thomas Levin; Søe, Kent

2011-01-01

A remarkable property of bone remodeling is that osteoblasts form bone matrix exactly where and when osteoclasts have removed it. The bone remodeling compartment (BRC) canopies that cover bone surfaces undergoing remodeling, were proposed to be critical players in this mechanism. Here, we provide...

Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck.

Science.gov (United States)

Liu, Yang; Wang, Jiawei

2017-11-01

To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant. Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts. A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect. Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Java project on periodontal diseases: periodontal bone loss in relation to environmental and systemic conditions

NARCIS (Netherlands)

Amaliya, A.; Laine, M.L.; Delanghe, J.R.; Loos, B.G.; van Wijk, A.J.; van der Velden, U.

2015-01-01

Objective To assess in a population deprived from regular dental care the relationship between alveolar bone loss (ABL) and environmental/systemic conditions. Material & Methods The study population consisted of subjects from the Purbasari tea estate on West Java, Indonesia. A full set of dental

Prevalence of alveolar bone loss in healthy children treated at private pediatric dentistry clinics.

Science.gov (United States)

Guimarães, Maria do Carmo Machado; de Araújo, Valéria Martins; Avena, Márcia Raquel; Duarte, Daniel Rocha da Silva; Freitas, Francisco Valter

2010-01-01

The purpose of this study was to evaluate the prevalence of alveolar bone loss (BL) in healthy children treated at private pediatric dentistry clinics in Brasília, Brazil. The research included 7,436 sites present in 885 radiographs from 450 children. The BL prevalence was estimated by measuring the distance from the cementoenamel junction (CEJ) to alveolar bone crest (ABC). Data were divided in groups: (I) No BL: distance from CEJ to ABC is 2 and 3 mm. Data were treated by the chi-square nonparametric test and Fisher's exact test (pchildren should never be underestimated because BL occurs even in healthy populations, although in a lower frequency.

Comparison of marginal bone loss and implant success between axial and tilted implants in maxillary All-on-4 treatment concept rehabilitations after 5 years of follow-up.

Science.gov (United States)

Hopp, Milena; de Araújo Nobre, Miguel; Maló, Paulo

2017-10-01

There is need for more scientific and clinical information on longer-term outcomes of tilted implants compared to implants inserted in an axial position. Comparison of marginal bone loss and implant success after a 5-year follow-up between axial and tilted implants inserted for full-arch maxillary rehabilitation. The retrospective clinical study included 891 patients with 3564 maxillary implants rehabilitated according to the All-on-4 treatment concept. The follow-up time was 5 years. Linear mixed-effect models were performed to analyze the influence of implant orientation (axial/tilted) on marginal bone loss and binary logistic regression to assess the effect of patient characteristics on occurrence of marginal bone loss >2.8 mm. Only those patients with measurements of at least one axial and one tilted implant available were analyzed. This resulted in a data set of 2379 implants (1201 axial, 1178 tilted) in 626 patients (=reduced data set). Axial and tilted implants showed comparable mean marginal bone losses of 1.14 ± 0.71 and 1.19 ± 0.82 mm, respectively. Mixed model analysis indicated that marginal bone loss levels at 5 years follow up was not significantly affected by the orientation (axial/tilted) of the implants in the maxillary bone. Smoking and female gender were associated with marginal bone loss >2.8 mm in a logistic regression analysis. Five-year implant success rates were 96%. The occurrence of implant failure showed to be statistically independent from orientation. Within the limitations of this study and considering a follow-up time of 5 years, it can be concluded that tilted implants behave similarly with regards to marginal bone loss and implant success in comparison to axial implants in full-arch rehabilitation of the maxilla. Longer-term outcomes (10 years +) are needed to verify this result. © 2017 Wiley Periodicals, Inc.

In vivo comparison of Kodak E-speed film and direct digital imaging system for assessment of interproximal bone loss

Directory of Open Access Journals (Sweden)

Mellekatte C Neetha

2014-01-01

Full Text Available Aims: To evaluate the diagnostic accuracy of direct digital radiography as compared to a conventional radiographic film for the assessment of interproximal bone loss with intrasurgical measurements as the gold standard. Materials and Methods: A total of 100 patients, with untreated moderate-to-advanced periodontal disease, were included in the study. The presurgical radiographs were made using a Kodak E-speed film and a Dexis digital sensor simultaneously, for sites with interproximal bone loss. At the time of surgery, the distance from the cementoenamel junction to the bone defect (CEJ-BD was measured for 331 interproximal defects. The radiographs were randomized and then linear measurements were taken for the same sites in both conventional and digital radiographs. Stastistical Analysis: Comparison between the conventional, digital, and intrasurgical measurements was done statistically using the Student′s t-test. The agreement and correlation among the methods was assessed using the weighted Kappa measure of agreement and Pearson′s correlation, respectively. Results: The results showed that the conventional (5.15 ± 2.19 mm and digital analyzing techniques (5.13 ± 2.19 mm underestimated the interproximal bone loss, as compared to the intrasurgical measurements (6.07 ± 2.05 mm (p < 0.001. The difference between conventional and digital radiographic methods was found to be statistically insignificant (p = 0.92. Conclusion: Under normal clinical use, the alveolar bone levels revealed on intraoral direct digital radiographs and Kodak E speed film were almost same. Therefore, the digital radiographic system can be routinely used in clinical practice as an alternative to conventional film.

Bone loss in rheumatoid arthritis. Influence of disease activity, duration of the disease, functional capacity, and corticosteroid treatment

DEFF Research Database (Denmark)

Hansen, M; Florescu, A; Stoltenberg, M

1996-01-01

Axial and appendicular bone mass were studied in 95 patients with rheumatoid arthritis. The aims were to quantify bone mineral density (BMD) and to evaluate the importance of disease activity, duration of disease, functional capacity, and corticosteroid treatment for bone loss in patients...... after the start of the disease. The overall functional capacity in terms of physical activity increased BMD in the axial skeleton. The local functional capacity in terms of grip strength was positively related to BMD in the appendicular skeleton. Patients with severe functional impairment had the lowest...

Performance evaluation of an irreversible Miller cycle comparing FTT (finite-time thermodynamics) analysis and ANN (artificial neural network) prediction

International Nuclear Information System (INIS)

Mousapour, Ashkan; Hajipour, Alireza; Rashidi, Mohammad Mehdi; Freidoonimehr, Navid

2016-01-01

In this paper, the first and second-laws efficiencies are applied to performance analysis of an irreversible Miller cycle. In the irreversible cycle, the linear relation between the specific heat of the working fluid and its temperature, the internal irreversibility described using the compression and expansion efficiencies, the friction loss computed according to the mean velocity of the piston and the heat-transfer loss are considered. The effects of various design parameters, such as the minimum and maximum temperatures of the working fluid and the compression ratio on the power output and the first and second-laws efficiencies of the cycle are discussed. In the following, a procedure named ANN is used for predicting the thermal efficiency values versus the compression ratio, and the minimum and maximum temperatures of the Miller cycle. Nowadays, Miller cycle is widely used in the automotive industry and the obtained results of this study will provide some significant theoretical grounds for the design optimization of the Miller cycle. - Highlights: • The performance of an irreversible Miller cycle is investigated using FFT. • The effects of design parameters on the performance of the cycle are investigated. • ANN is applied to predict the thermal efficiency and the power output values. • There is an excellent correlation between FTT and ANN data. • ANN can be applied to predict data where FTT analysis has not been performed.

Conductive hearing loss and bone conduction devices: restored binaural hearing?

Science.gov (United States)

Agterberg, Martijn J H; Hol, Myrthe K S; Cremers, Cor W R J; Mylanus, Emmanuel A M; van Opstal, John; Snik, Ad F M

2011-01-01

An important aspect of binaural hearing is the proper detection of interaural sound level differences and interaural timing differences. Assessments of binaural hearing were made in patients with acquired unilateral conductive hearing loss (UCHL, n = 11) or congenital UCHL (n = 10) after unilateral application of a bone conduction device (BCD), and in patients with bilateral conductive or mixed hearing loss after bilateral BCD application. Benefit (bilateral versus unilateral listening) was assessed by measuring directional hearing, compensation of the acoustic head shadow, binaural summation and binaural squelch. Measurements were performed after an acclimatization time of at least 10 weeks. Unilateral BCD application was beneficial, but there was less benefit in the patients with congenital UCHL as compared to patients with acquired UCHL. In adults with bilateral hearing loss, bilateral BCD application was clearly beneficial as compared to unilateral BCD application. Binaural summation was present, but binaural squelch could not be proven. To explain the poor results in the patients with congenital UCHL, two factors seemed to be important. First, a critical period in the development of binaural hearing might affect the binaural hearing abilities. Second, crossover stimulation, referring to additional stimulation of the cochlea contralateral to the BCD side, might deteriorate binaural hearing in patients with UCHL. Copyright © 2011 S. Karger AG, Basel.

Irreversible dynamics, Onsager-Casimir symmetry, and an application to turbulence.

Science.gov (United States)

Ottinger, Hans Christian

2014-10-01

Irreversible contributions to the dynamics of nonequilibrium systems can be formulated in terms of dissipative, or irreversible, brackets. We discuss the structure of such irreversible brackets in view of a degeneracy implied by energy conservation, where we consider different types of symmetries of the bracket corresponding to the Onsager and Casimir symmetries of linear irreversible thermodynamics. Slip and turbulence provide important examples of antisymmetric irreversible brackets and offer guidance for the more general modeling of irreversible dynamics without entropy production. Conversely, turbulence modeling could benefit from elucidating thermodynamic structure. The examples suggest constructing antisymmetric irreversible brackets in terms of completely antisymmetric functions of three indices. Irreversible brackets without well-defined symmetry properties can arise for rare events, causing big configurational changes.

Aging of marrow stromal (skeletal) stem cells and their contribution to age-related bone loss

DEFF Research Database (Denmark)

Bellantuono, Ilaria; Aldahmash, Abdullah; Kassem, Moustapha

2009-01-01

Marrow stromal cells (MSC) are thought to be stem cells with osteogenic potential and therefore responsible for the repair and maintenance of the skeleton. Age related bone loss is one of the most prevalent diseases in the elder population. It is controversial whether MSC undergo a process of agi...

Telomerase-Deficient Mice Exhibit Bone Loss Owing to Defects in Osteoblasts and Increased Osteoclastogenesis by Inflammatory Microenvironment

DEFF Research Database (Denmark)

Saeed, H.; Abdallah, B. M.; Ditzel, N.

2011-01-01

Telomere shortening owing to telomerase deficiency leads to accelerated senescence of human skeletal (mesenchymal) stem cells (MSCs) in vitro, whereas overexpression leads to telomere elongation, extended life span, and enhanced bone formation. To study the role of telomere shortening in vivo, we...... studied the phenotype of telomerase-deficient mice (Terc(-/-)).Terc(-/-) mice exhibited accelerated age-related bone loss starting at 3 months of age and during 12 months of follow-up revealed by dual-energy X-ray absorptiometric (DXA) scanning and by micro-computed tomography (mu CT). Bone...... histomorphometry revealed decreased mineralized surface and bone-formation rate as well as increased osteoclast number and size in Terc(-/-) mice. Also, serum total deoxypyridinoline (tDPD) was increased in Terc(-/-) mice. MSCs and osteoprogenitors isolated from Terc(-l-) mice exhibited intrinsic defects...

Monitoring of Bone Loss Biomarkers in Human Sweat: A Non-Invasive, Time Efficient Means of Monitoring Bone Resorption Markers under Micro and Partial Gravity Loading Conditions

Data.gov (United States)

National Aeronautics and Space Administration — The overall goal of this project was to validate the concept that the rate and extent of unloading-induced bone loss in humans can be assessed by monitoring the...

Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

KAUST Repository

Shang, Ran; Vuong, Francois; Hu, Jingyi; Li, Sheng; Kemperman, Antoine J.B.; Nijmeijer, Kitty; Cornelissen, Emile R.; Heijman, Sebastiaan G.J.; Rietveld, Luuk C.

2015-01-01

The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

KAUST Repository

Shang, Ran

2015-05-06

The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

High-dose therapy improved the bone remodelling compartment canopy and bone formation in multiple myeloma

DEFF Research Database (Denmark)

Hinge, Maja; Delaissé, Jean-Marie; Plesner, Torben

2015-01-01

transplantation, and from 20 control patients with monoclonal gammopathy of undetermined significance were histomorphometrically investigated. This investigation confirmed that MM patients exhibited uncoupled bone formation to resorption and reduced canopy coverage. More importantly, this study revealed......Bone loss in multiple myeloma (MM) is caused by an uncoupling of bone formation to resorption trigged by malignant plasma cells. Increasing evidence indicates that the bone remodelling compartment (BRC) canopy, which normally covers the remodelling sites, is important for coupled bone remodelling....... Loss of this canopy has been associated with bone loss. This study addresses whether the bone remodelling in MM is improved by high-dose therapy. Bone marrow biopsies obtained from 20 MM patients, before and after first-line treatment with high-dose melphalan followed by autologous stem cell...

Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength

DEFF Research Database (Denmark)

Ulhøi, Maiken Parm; Meldgaard, Karoline; Steiniche, Torben

2017-01-01

Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual-energy X......-ray absorptiometry (DEXA), compression testing, ashing, and bone histomorphometry were performed. Individuals with CAA had significantly lower bone mineral density (BMD) in the femoral neck and significantly lower bone volume demonstrated by thinner trabeculae, decreased extent of osteoid surfaces, and lower mean...... wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. Conclusion: CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone...

Possible Role of Garlic Oil and Parsley Extract in Ameliorating Radiation-Induced Bone Loss in Female Rats

International Nuclear Information System (INIS)

Ramadan, L.; El-Sabbagh, W.; Kenawy, S.

2011-01-01

To Investigate the possible protective effect of garlic oil and parsley extract against bone loss resulted in female virgin rats exposed to fractionated doses of gamma-radiation (1 Gy 3 times weekly for 5 weeks). Urinary calcium (U Ca), calcium to creatinine ratio (Ca/Cr), hydroxyproline and serum phosphorus were measured as bone resorption bio markers, while serum osteocalcine (OST) and serum alkaline phosphatase (ALP) were measured as bone formation bio markers. Furthermore, nitric oxide (NO) which represents the balance in bone remodeling was measured. Malondiadehyde level (MDA) as well as superoxide dismutase activity (SOD) was measured as oxidative stress bio markers. Female irradiated rats in the present study had significant increases in both bone resorption and bone formation bio markers after 6 weeks from the last exposure to gamma-radiation. Irradiated rats also had significant decreases in plasma NO indicating imbalance in bone remodeling as well as significant increase in oxidative stress bio markers. Daily treatment with garlic oil extracted in olive oil improved all measured parameters except OST level, while the vehicle used for garlic oil (extra virgin olive oil) significantly decreased bone resorption bio markers. Parsley extract induced normalization to all bone resorption and formation parameters measured in irradiated rats. Daily administration of garlic oil and parsley extract protected the bone from degeneration induced by exposure to fractionated doses of gamma radiation.

High Prevalence of Suboptimal Vitamin D Status and Bone Loss in Adult Short Bowel Syndrome Even After Weaning Off Parenteral Nutrition.

Science.gov (United States)

Fan, Shengxian; Ni, Xiaodong; Wang, Jian; Zhang, Yongliang; Tao, Shen; Kong, Wencheng; Li, Yousheng; Li, Jieshou

2017-04-01

Previous studies have noticed the high incidence of suboptimal vitamin D (VtD) status and bone loss in short bowel syndrome (SBS) with parenteral nutrition (PN) dependence. However, limited data have focused on adult SBS without PN dependence. Therefore, our objective was to investigate the incidence and risk factors of suboptimal VtD status and bone loss in adult SBS even after weaning off PN. We performed a prospective study of 60 adult patients with SBS. Serum 25-hydroxyvitamin D (25-OHD) was measured by radioimmunoassay. Bone mineral density (BMD) was measured using dual-energy x-ray absorptiometry (DEXA). Medical records and various laboratory parameters were collected in all participants. Suboptimal VtD status was identified in all individuals, including 3 (5.0%) with VtD insufficiency and 57 (95.0%) with VtD deficiency. Residual small bowel length (B, 0.072, P = .001) and duration of SBS (B, -0.066, P = .020) were both significantly correlated with suboptimal VtD levels. Overall, only 2 patients presented a normal BMD; osteopenia and osteoporosis were noted in 41 (68.3%) and 17 (28.3%) individuals, respectively. Low 25-OHD concentration was associated with a decreased BMD (B, 0.065, P = .029). There were no other demographic characteristics or clinical examinations associated with suboptimal VtD levels and bone loss. Suboptimal VtD status and bone loss were common in adult SBS even after weaning off PN. Despite routine oral VtD supplementation, most patients did not achieve satisfactory status. This emphasizes the critical importance of routine surveillance of 25-OHD and BMD, as well as consideration of alternative methods of supplementation after weaning off PN.

Epiphyseal abnormalities, trabecular bone loss and articular chondrocyte hypertrophy develop in the long bones of postnatal Ext1-deficient mice.

Science.gov (United States)

Sgariglia, Federica; Candela, Maria Elena; Huegel, Julianne; Jacenko, Olena; Koyama, Eiki; Yamaguchi, Yu; Pacifici, Maurizio; Enomoto-Iwamoto, Motomi

2013-11-01

Long bones are integral components of the limb skeleton. Recent studies have indicated that embryonic long bone development is altered by mutations in Ext genes and consequent heparan sulfate (HS) deficiency, possibly due to changes in activity and distribution of HS-binding/growth plate-associated signaling proteins. Here we asked whether Ext function is continuously required after birth to sustain growth plate function and long bone growth and organization. Compound transgenic Ext1(f/f);Col2CreERT mice were injected with tamoxifen at postnatal day 5 (P5) to ablate Ext1 in cartilage and monitored over time. The Ext1-deficient mice exhibited growth retardation already by 2weeks post-injection, as did their long bones. Mutant growth plates displayed a severe disorganization of chondrocyte columnar organization, a shortened hypertrophic zone with low expression of collagen X and MMP-13, and reduced primary spongiosa accompanied, however, by increased numbers of TRAP-positive osteoclasts at the chondro-osseous border. The mutant epiphyses were abnormal as well. Formation of a secondary ossification center was significantly delayed but interestingly, hypertrophic-like chondrocytes emerged within articular cartilage, similar to those often seen in osteoarthritic joints. Indeed, the cells displayed a large size and round shape, expressed collagen X and MMP-13 and were surrounded by an abundant Perlecan-rich pericellular matrix not seen in control articular chondrocytes. In addition, ectopic cartilaginous outgrowths developed on the lateral side of mutant growth plates over time that resembled exostotic characteristic of children with Hereditary Multiple Exostoses, a syndrome caused by Ext mutations and HS deficiency. In sum, the data do show that Ext1 is continuously required for postnatal growth and organization of long bones as well as their adjacent joints. Ext1 deficiency elicits defects that can occur in human skeletal conditions including trabecular bone loss

Comparative effects of riboflavin, nicotinamide and folic acid on alveolar bone loss: A morphometric and histopathologic study in rats

Directory of Open Access Journals (Sweden)

Akpınar Aysun

2016-01-01

Full Text Available Introduction. Periodontitis is a chronic inflammatory and osteolytic disease. Vitamin B complex is a class of water-soluble vitamins that play important roles in cell metabolism. Objective. The aim of this study was to evaluate the effects of riboflavin (RBF, nicotinamide (NA, and folic acid (FA on alveolar bone loss in experimental periodontitis rat model. Methods. Sixty-four male Wistar rats were randomly divided into the following eight groups: Control, Ligated, RBF50 (RBF, 50 mg/kg daily, NA50 (NA, 50 mg/kg daily, FA50 (FA, 50 mg/kg daily, RBF100 (RBF, 100 mg/kg daily, NA100 (NA, 100 mg/kg daily, and FA100 (FA, 100 mg/kg daily. Periodontitis was induced using silk ligature around the right first mandibular molar. After 11 days the rats were sacrificed. Mandible and serum samples were collected. Changes in alveolar bone levels were measured clinically, and periodontal tissues were examined histopathologically. Serum IL-1β (pg/ml levels were analyzed by using ELISA. Results. Mean alveolar bone loss in the mandibular first molar tooth revealed to be significantly lower in RBF100 group than in the Control group. In the Ligated group, alveolar bone loss was significantly higher than in all other groups. The ratio of presence of inflammatory cell infiltration in the Ligated group was significantly higher than in the Control group. The differences in the serum IL-1β levels between the groups were not statistically significant. Osteoclasts that were observed in the Ligated group were significantly higher than those of the Control and FA100 groups. The osteoblastic activity in the Ligated group, RBF100, and NA100 groups were shown to be significantly higher than those in the Control group. Conclusion. This study has demonstrated that systemic administration of RBF, NA, and FA in different dosages (50-100 mg/kg reduced alveolar bone loss in periodontal disease in rats.

The loss of activating transcription factor 4 (ATF4) reduces bone toughness and fracture toughness.

Science.gov (United States)

Makowski, Alexander J; Uppuganti, Sasidhar; Wadeer, Sandra A; Whitehead, Jack M; Rowland, Barbara J; Granke, Mathilde; Mahadevan-Jansen, Anita; Yang, Xiangli; Nyman, Jeffry S

2014-05-01

Even though age-related changes to bone tissue affecting fracture risk are well characterized, only a few matrix-related factors have been identified as important to maintaining fracture resistance. As a gene critical to osteoblast differentiation, activating transcription factor 4 (ATF4) is possibly one of these important factors. To test the hypothesis that the loss of ATF4 affects the fracture resistance of bone beyond bone mass and structure, we harvested bones from Atf4+/+ and Atf4-/- littermates at 8 and 20 weeks of age (n≥9 per group) for bone assessment across several length scales. From whole bone mechanical tests in bending, femurs from Atf4-/- mice were found to be brittle with reduced toughness and fracture toughness compared to femurs from Atf4+/+ mice. However, there were no differences in material strength and in tissue hardness, as determined by nanoindentation, between the genotypes, irrespective of age. Tissue mineral density of the cortex at the point of loading as determined by micro-computed tomography was also not significantly different. However, by analyzing local composition by Raman Spectroscopy (RS), bone tissue of Atf4-/- mice was found to have higher mineral to collagen ratio compared to wild-type tissue, primarily at 20 weeks of age. From RS analysis of intact femurs at 2 orthogonal orientations relative to the polarization axis of the laser, we also found that the organizational-sensitive peak ratio, ν1Phosphate per Amide I, changed to a greater extent upon bone rotation for Atf4-deficient tissue, implying bone matrix organization may contribute to the brittleness phenotype. Target genes of ATF4 activity are not only important to osteoblast differentiation but also in maintaining bone toughness and fracture toughness. Published by Elsevier Inc.

Constitutively Elevated Blood Serotonin Is Associated with Bone Loss and Type 2 Diabetes in Rats.

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Igor Erjavec

Full Text Available Reduced peripheral serotonin (5HT in mice lacking tryptophan hydroxylase (TPH1, the rate limiting enzyme for 5HT synthesis, was reported to be anabolic to the skeleton. However, in other studies TPH1 deletion either had no bone effect or an age dependent inhibition of osteoclastic bone resorption. The role of 5HT in bone therefore remains poorly understood. To address this issue, we used selective breeding to create rat sublines with constitutively high (high-5HT and low (low-5HT platelet 5HT level (PSL and platelet 5HT uptake (PSU. High-5HT rats had decreased bone volume due to increased bone turnover characterized by increased bone formation and mineral apposition rate, increased osteoclast number and serum C-telopeptide level. Daily oral administration of the TPH1 inhibitor (LX1032 for 6 weeks reduced PSL and increased the trabecular bone volume and trabecular number of the spine and femur in high-5HT rats. High-5HT animals also developed a type 2 diabetes (T2D phenotype with increased: plasma insulin, glucose, hemoglobin A1c, body weight, visceral fat, β-cell pancreatic islets size, serum cholesterol, and decreased muscle strength. Serum calcium accretion mediated by parathyroid hormone slightly increased, whereas treatment with 1,25(OH2D3 decreased PSL. Insulin reduction was paralleled by a drop in PSL in high-5HT rats. In vitro, insulin and 5HT synergistically up-regulated osteoblast differentiation isolated from high-5HT rats, whereas TPH1 inhibition decreased the number of bone marrow-derived osteoclasts. These results suggest that constitutively elevated PSL is associated with bone loss and T2D via a homeostatic interplay between the peripheral 5HT, bone and insulin.

The Loss of Activating Transcription Factor 4 (ATF4) Reduces Bone Toughness and Fracture Toughness

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Makowski, Alexander J.; Uppuganti, Sasidhar; Waader, Sandra A.; Whitehead, Jack M.; Rowland, Barbara J.; Granke, Mathilde; Mahadevan-Jansen, Anita; Yang, Xiangli; Nyman, Jeffry S.

2014-01-01

Even though age-related changes to bone tissue affecting fracture risk are well characterized, only a few matrix-related factors have been identified as important to maintaining fracture resistance. As a gene critical to osteoblast differentiation, activating transcription factor 4 (ATF4) is possibly one of the seimportant factors. To test the hypothesis that the loss of ATF4 affects the fracture resistance of bone beyond bone mass and structure, we harvested bones from Atf4+/+ and Atf4−/− littermates at 8 and 20 weeks of age (n≥9 per group) for bone assessment across several length scales. From whole bone mechanical tests in bending, femurs from Atf4−/− mice were found to be brittle with reduced toughness and fracture toughness compared to femurs from Atf4+/+ mice. However, there were no differences in material strength and in tissue hardness, as determined by nanoindentation, between the genotypes, irrespective age. Tissue mineral density of the cortex at the point of loading as determined by micro-computed tomography was also not significantly different. However, by analyzing local composition by Raman Spectroscopy (RS), bone tissue of Atf4−/− mice was found to have higher mineral to collagen ratio compared to wild-type tissue, primarily at 20 weeks of age. From RS analysis of intact femurs at 2 orthogonal orientations relative to the polarization axis of the laser, we also found that the organizational-sensitive peak ratio, ν1 Phosphate per Amide I, changed to a greater extent upon bone rotation for Atf4-deficient tissue, implying bone matrix organization may contribute to the brittleness phenotype. Target genes of ATF4 activity are not only important to osteoblast differentiation but also maintaining bone toughness and fracture toughness. PMID:24509412

Igfbp2 Deletion in Ovariectomized Mice Enhances Energy Expenditure but Accelerates Bone Loss.

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DeMambro, Victoria E; Le, Phuong T; Guntur, Anyonya R; Maridas, David E; Canalis, Ernesto; Nagano, Kenichi; Baron, Roland; Clemmons, David R; Rosen, Clifford J

2015-11-01

Previously, we reported sexually dimorphic bone mass and body composition phenotypes in Igfbp2(-/-) mice (-/-), where male mice exhibited decreased bone and increased fat mass, whereas female mice displayed increased bone but no changes in fat mass. To investigate the interaction between IGF-binding protein (IGFBP)-2 and estrogen, we subjected Igfbp2 -/- and +/+ female mice to ovariectomy (OVX) or sham surgery at 8 weeks of age. At 20 weeks of age, mice underwent metabolic cage analysis and insulin tolerance tests before killing. At harvest, femurs were collected for microcomputed tomography, serum for protein levels, brown adipose tissue (BAT) and inguinal white adipose tissue (IWAT) adipose depots for histology, gene expression, and mitochondrial respiration analysis of whole tissue. In +/+ mice, serum IGFBP-2 dropped 30% with OVX. In the absence of IGFBP-2, OVX had no effect on preformed BAT; however, there was significant "browning" of the IWAT depot coinciding with less weight gain, increased insulin sensitivity, lower intraabdominal fat, and increased bone loss due to higher resorption and lower formation. Likewise, after OVX, energy expenditure, physical activity and BAT mitochondrial respiration were decreased less in the OVX-/- compared with OVX+/+. Mitochondrial respiration of IWAT was reduced in OVX+/+ yet remained unchanged in OVX-/- mice. These changes were associated with significant increases in Fgf21 and Foxc2 expression, 2 proteins known for their insulin sensitizing and browning of WAT effects. We conclude that estrogen deficiency has a profound effect on body and bone composition in the absence of IGFBP-2 and may be related to changes in fibroblast growth factor 21.

High-fat diet exacerbates pain-like behaviors and periarticular bone loss in mice with CFA-induced knee arthritis.

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Loredo-Pérez, Aleyda A; Montalvo-Blanco, Carlos E; Hernández-González, Luis I; Anaya-Reyes, Maricruz; Fernández Del Valle-Laisequilla, Cecilia; Reyes-García, Juan G; Acosta-González, Rosa I; Martínez-Martínez, Arisai; Villarreal-Salcido, Jaira C; Vargas-Muñoz, Virginia M; Muñoz-Islas, Enriqueta; Ramírez-Rosas, Martha B; Jiménez-Andrade, Juan M

2016-05-01

Our aim was to quantify nociceptive spontaneous behaviors, knee edema, proinflammatory cytokines, bone density, and microarchitecture in high-fat diet (HFD)-fed mice with unilateral knee arthritis. ICR male mice were fed either standard diet (SD) or HFD starting at 3 weeks old. At 17 weeks, HFD and SD mice received intra-articular injections either with Complete Freund's Adjuvant (CFA) or saline into the right knee joint every 7 days for 4 weeks. Spontaneous pain-like behaviors and knee edema were assessed for 26 days. At day 26 post-first CFA injection, serum levels of IL-1β, IL-6, and RANKL were measured by ELISA, and microcomputed tomography analysis of knee joints was performed. HFD-fed mice injected with CFA showed greater spontaneous pain-like behaviors of the affected extremity as well as a decrease in the weight-bearing index compared to SD-fed mice injected with CFA. Knee edema was not significantly different between diets. HFD significantly exacerbated arthritis-induced bone loss at the distal femoral metaphysis but had no effect on femoral diaphyseal cortical bone. HFD did not modify serum levels of proinflammatory cytokines. HFD exacerbates pain-like behaviors and significantly increases the magnitude of periarticular trabecular bone loss in a murine model of unilateral arthritis. © 2016 The Obesity Society.

Combined aerobic and resistance exercise is effective for achieving weight loss and reducing cardiovascular risk factors without deteriorating bone health in obese young adults

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Jung Sub Lim

2013-03-01

Full Text Available PurposeWeight loss reduces cardiovascular risk factors in the obese. However, weight reduction through diet negatively affects long-term bone health. The aim of study was to determine the ability of combined aerobic and resistance exercise (CE to reduce weight and cardiovascular risk without diminishing bone health.MethodsTwenty-five young adults participated in an 8-week weight loss CE program. Subjects were allocated to an obese group or a control group by body mass index (BMI. Body weight, BMI, body composition, and bone mineral density (BMD of the lumbar spine and total hip were measured before and after the CE trial. Serum levels of metabolic markers, including adipokines and bone markers, were also evaluated.ResultsWeight loss was evident in the obese group after the 8 weeks CE trial. Fat mass was significantly reduced in both groups. Fasting insulin, homeostatic model assessment-insulin resistance (HOMA-IR, leptin and aminotransferases level were significantly reduced from baseline only in the obese group. High density lipoprotein cholesterol increased in both groups. Hip BMD increased in the obese group. In all study subjects, BMI changes were correlated with HOMA-IR, leptin, and HDL changes. BMI decreases were correlated with lumbar spine BMD increases, lumbar spine BMD increases were positively correlated with osteocalcin changes, and lumbar spine bone mineral content increases were correlated negatively with C-terminal telopeptide of type 1 collagen changes.ConclusionThese findings suggest that CE provides effective weight loss and improves cardiovascular risk factors without diminishing BMD. Furthermore, they indicate that lumbar spine BMD might be maintained by increasing bone formation and decreasing bone resorption.

Diet-induced obesity, gut microbiota and bone, including alveolar bone loss.

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Eaimworawuthikul, Sathima; Thiennimitr, Parameth; Chattipakorn, Nipon; Chattipakorn, Siriporn C

2017-06-01

Obesity is a major risk factor for several pathologies, including jaw bone resorption. The underlying mechanisms involved in pathological conditions resulting from obesity include chronic systemic inflammation and the development of insulin resistance. Although numerous studies have indicated the importance of the role of gut microbiota in the pathogenesis of inflammation and insulin resistance in obesity, only a few studies have established a relationship between obesity, gut microbiota and status of the jaw bone. This review aims to summarize current findings relating to these issues, focusing on the role of obesity and gut microbiota on jaw bone health, including possible mechanisms which can explain this link. Copyright © 2017 Elsevier Ltd. All rights reserved.

Irreversibility and dissipation in finite-state automata

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Ganesh, Natesh; Anderson, Neal G.

2013-01-01

Irreversibility and dissipation in finite-state automata (FSA) are considered from a physical-information-theoretic perspective. A quantitative measure for the computational irreversibility of finite automata is introduced, and a fundamental lower bound on the average energy dissipated per state transition is obtained and expressed in terms of FSA irreversibility. The irreversibility measure and energy bound are germane to any realization of a deterministic automaton that faithfully registers abstract FSA states in distinguishable states of a physical system coupled to a thermal environment, and that evolves via a sequence of interactions with an external system holding a physical instantiation of a random input string. The central result, which is shown to follow from quantum dynamics and entropic inequalities alone, can be regarded as a generalization of Landauer's Principle applicable to FSAs and tailorable to specified automata. Application to a simple FSA is illustrated.

Tissue Specific Expression Of Sprouty1 In Mice Protects Against High Fat Diet Induced Fat Accumulation, Bone Loss, And Metabolic Dysfunction

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Urs, Sumithra; Henderson, Terry; Le, Phuong; Rosen, Clifford J.; Liaw, Lucy

2012-01-01

We recently characterized Sprouty1 (Spry1), a growth factor signaling inhibitor as a regulator of marrow progenitor cells promoting osteoblast differentiation at the expense of adipocytes. Adipose tissue specific Spry1 expression in mice resulted in increased bone mass and reduced body fat while conditional knockout of Spry1 had the opposite effect with decreased bone and increased body fat. Because Spry1 suppresses normal fat development, we tested the hypothesis that Spry1 expression prevents high fat diet-induced obesity, bone loss, and associated lipid abnormalities and demonstrate that Spry1 has a long-term protective effect on mice fed a high caloric diet. We studied diet-induced obesity in mice with fatty acid binding promoter (aP2)-driven expression or conditional knockout of Spry1 in adipocytes. Phenotyping was performed by whole body dual-energy X-ray absorptiometry, microCT, histology and blood analysis. In conditional Spry1 null mice, high fat diet increased body fat by 40%, impaired glucose regulation, and led to liver steatosis. However, over-expression of Spry1 led to 35% lower body fat, reduced bone loss, and normal metabolic function compared to single transgenics. This protective phenotype was associated with decreased circulating insulin (70%) and leptin (54%) compared to controls on a high fat diet. Additionally, Spry1 expression decreased adipose tissue inflammation by 45%. We show that conditional Spry1 expression in adipose tissue protects against high fat diet-induced obesity and associated bone loss. PMID:22142492

Comparative study of irreversibilities in an aqua-ammonia absorption refrigeration system

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Ataer, O E [Gazi Univ., Ankara (TR). Mechanical Engineering Dept.; Gogus, Y [Middle East Technical Univ., Ankara (Turkey)

1991-03-01

Irreversibilities in components of an aqua-ammonia absorption refrigeration system (ARS) have been determined by second law analysis. The components of the ARS are as follows: condenser, evaporator, absorber, generator, pump, expansion valves, mixture heat exchanger and refrigerant heat exchanger. It is assumed that the ammonia concentration at the generator exit is, independent of the other parameters, equal to 0.999 and at the evaporator exit the gas is saturated vapour. Pressure losses between the generator and condenser, and the evaporator and absorber are taken into consideration. In the results the dimensionless exergy loss of each component, the exergetic coefficient of performance, the coefficient of performance and the circulation ratio are given graphically for each different generator, evaporator, condenser and absorber temperature. (author).

Presbycusis: a human temporal bone study of individuals with flat audiometric patterns of hearing loss using a new method to quantify stria vascularis volume.

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Nelson, Erik G; Hinojosa, Raul

2003-10-01

The purpose of this study was to determine the prevalence of stria vascularis atrophy in individuals with presbycusis and flat audiometric patterns of hearing loss. Individuals with presbycusis have historically been categorized by the shape of their audiograms, and flat audiometric thresholds have been reported to be associated with atrophy of the stria vascularis. Stria vascularis volume was not measured in these studies. Retrospective case review. Archival human temporal bones from individuals with presbycusis were selected on the basis of strict audiometric criteria for flat audiometric thresholds. Six temporal bones that met these criteria were identified and compared with 10 temporal bones in individuals with normal hearing. A unique quantitative method was developed to measure the stria vascularis volume in these temporal bones. The hair cell and spiral ganglion cell populations also were quantitatively evaluated. Only one of the six individuals with presbycusis and flat audiometric thresholds had significant atrophy of the stria vascularis. This individual with stria vascularis atrophy also had reduced inner hair cell, outer hair cell, and ganglion cell populations. Three of the individuals with presbycusis had spiral ganglion cell loss, three individuals had inner hair cell loss, and all six individuals had outer hair cell loss. The results of this investigation suggest that individuals with presbycusis and flat audiometric patterns of hearing loss infrequently have stria vascularis atrophy. Outer hair cell loss alone or in combination with inner hair cell or ganglion cell loss may be the cause of flat audiometric thresholds in individuals with presbycusis.

Preventive effects of bee pollen Cistus ladaniferus extract on bone loss in ovariectomized rats in vivo

International Nuclear Information System (INIS)

Yamaguchi, Masayoshi; Uchiyama, Satoshi; Nakagawa, Taeko

2007-01-01

The effect of bee pollen Cistus ladaniferus extract on ovariectomy (OVX)-induced bone loss in vivo was investigated. The water-solubilized extracts were obtained from the bee pollen of Cistus ladaniferus. Cistus extract (5.0 or 10.0 mg/100 g body weight) was orally administered once daily for 30 days to OVX rats. The analysis using a peripheral quantitative computed tomography (pQCT) showed that OVX-induced a significant decrease in mineral content, mineral density, and polar strength strain index in the femoral-metaphyseal tissues. These decreases were significantly prevented after the administration of Cistus extract (10.0 mg/100 g). Moreover, OVX-induced a significant decrease in calcium content in the femoral-diaphyseal and -metaphyseal tissues. This decrease was significantly prevented after the administration of cistus extract (5.0 or 10.0 mg/100 g). This study demonstrates that cistus extract has a preventive effect on OVX-induced bone loss in vivo. (author)

Vitamin D Supplementation in Elderly Black Women Does Not Prevent Bone Loss, a Randomized Controlled Trial.

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Aloia, John F; Fazzari, Melissa; Islam, Shahidul; Mikhail, Mageda; Katumuluwa, Subhashini; Dhaliwal, Ruban; Stolberg, Alexandra; Usera, Gianina; Ragolia, Louis

2018-06-15

Black Americans have lower levels of serum 25(OH)D but superior bone health compared to white Americans. There is controversy over whether they should be screened for vitamin D deficiency and have higher vitamin D requirements than recommended by the Institute of Medicine (IOM). The purpose of this trial was to determine whether Vitamin D supplementation in elderly black women prevents bone loss. 260 healthy black American women, 60 years of age and older were recruited to take part in a two arm, double-dummy 3 year RCT of vitamin D 3 vs. placebo. The study was conducted in an ambulatory clinical research center. Vitamin D 3 dose was adjusted to maintain serum 25(OH)D above 75 nmol/L. Bone mineral density (BMD) and serum were measured for [parathyroid hormone (PTH), C-terminal crosslink telopeptide (CTX) and bone specific alkaline phosphatase (BSAP) every 6 months. Baseline serum 25(OH)D 3 was 54.8 ± 16.8 nmol/L. There was no group xtime interaction effect for any BMD measurement. For all BMD measurements, except for total body and spine, there was a statistically significant negative effect of time (P D above 75 nmol/L is comparable to the rate of loss with serum 25(OH)D at the RDA of 50 nmol/L. Black Americans should have the same exposure to vitamin D as white Americans. The trial was registered at clinical trials.gov: NCT01153568. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Deoxypyridinoline level in gingival crevicular fluid as alveolar bone loss biomarker in periodontal disease

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Agustin Wulan Suci Dharmayanti

2012-06-01

Full Text Available Background: Periodontal diseases have high prevalence in Indonesia. They are caused by bacteria plaque that induced host response to release pro inflammatory mediator. Pro inflammatory mediators and bacteria product cause degradation of collagen fibers in periodontal tissue. Deoxypyridinoline is one of pyridinoline cross-link of collagen type I that can be used as biomarker in bone metabolic diseases, however, their contribution to detect alveolar bone loss in periodontal diseases remains unclear. Purpose: This study was to evaluate deoxypyridinoline level in gingival crevicular fluid as alveolar bone loss biomarker on periodontal disease. Methods: This study used 24 subjects with periodontal diseases and 6 healthy subjects. Dividing of periodontal disease was based on index periodontal. Gingival crevicular fluid was taken at mesial site of maxillary posterior tooth by paper point and deoxypyridinoline be measured by ELISA technique. Results: We found increasing of deoxypyridinoline level following of the severity of periodontal diseases. There was also significant difference between healthy subjects and periodontal diseases subjects (p<0.05. Conclusion: Deoxypyridinoline level in gingiva crevicular fluid can be used as alveolar bone loss biomarker in periodontal disease subjects.Latar belakang: Prevalensi penyakit periodontal di Indonesia cukup tinggi. Ini disebabkan oleh bakteri plak yang merangsang respon tubuh untuk mengeluarkan mediator keradangan. Mediator keradangan dan produk bakteri menyebabkan degradasi serat kolagen jaringan periodontal. Deoksipiridinolin merupakan salah satu ikatan piridinium dari kolagen tipe I yang dapat digunakan sebagai biomarker penyakit metabolisme tubuh. Akan tetapi, penggunaan deoksipiridinolin untuk mendeteksi kehilangan tulang alveolar pada penyakit periodontal masih belum jelas. Tujuan: Tujuan penelitian ini untuk mengetahui bahwa kadar deoksipiridinolin pada cairan krevikular gingival dapat digunakan

Extended Irreversible Thermodynamics

CERN Document Server

Jou, David

2010-01-01

This is the 4th edition of the highly acclaimed monograph on Extended Irreversible Thermodynamics, a theory that goes beyond the classical theory of irreversible processes. In contrast to the classical approach, the basic variables describing the system are complemented by non-equilibrium quantities. The claims made for extended thermodynamics are confirmed by the kinetic theory of gases and statistical mechanics. The book covers a wide spectrum of applications, and also contains a thorough discussion of the foundations and the scope of the current theories on non-equilibrium thermodynamics. For this new edition, the authors critically revised existing material while taking into account the most recent developments in fast moving fields such as heat transport in micro- and nanosystems or fast solidification fronts in materials sciences. Several fundamental chapters have been revisited emphasizing physics and applications over mathematical derivations. Also, fundamental questions on the definition of non-equil...

Presbycusis: a human temporal bone study of individuals with downward sloping audiometric patterns of hearing loss and review of the literature.

Science.gov (United States)

Nelson, Erik G; Hinojosa, Raul

2006-09-01

The purpose of this retrospective case review was to identify patterns of cochlear element degeneration in individuals with presbycusis exhibiting downward sloping audiometric patterns of hearing loss and to correlate these findings with those reported in the literature to clarify conflicting concepts regarding the association between hearing loss and morphologic abnormalities. Archival human temporal bones from individuals with presbycusis were selected on the basis of strict audiometric criteria for downward-sloping audiometric thresholds. Twenty-one temporal bones that met these criteria were identified and compared with 10 temporal bones from individuals with normal hearing. The stria vascularis volumes, spiral ganglion cell populations, inner hair cells, and outer hair cells were quantitatively evaluated. The relationship between the severity of hearing loss and the degeneration of cochlear elements was analyzed using univariate linear regression models. Outer hair cell loss and ganglion cell loss was observed in all individuals with presbycusis. Inner hair cell loss was observed in 18 of the 21 individuals with presbycusis and stria vascularis loss was observed in 10 of the 21 individuals with presbycusis. The extent of degeneration of all four of the cochlear elements evaluated was highly associated with the severity of hearing loss based on audiometric thresholds at 8,000 Hz and the pure-tone average at 500, 1,000, and 2,000 Hz. The extent of ganglion cell degeneration was associated with the slope of the audiogram. Individuals with downward-sloping audiometric patterns of presbycusis exhibit degeneration of the stria vascularis, spiral ganglion cells, inner hair cells, and outer hair cells that is associated with the severity of hearing loss. This association has not been previously reported in studies that did not use quantitative methodologies for evaluating the cochlear elements and strict audiometric criteria for selecting cases.

Effects of β-Glucans Ingestion on Alveolar Bone Loss, Intestinal Morphology, Systemic Inflammatory Profile, and Pancreatic β-Cell Function in Rats with Periodontitis and Diabetes

Science.gov (United States)

Silva, Viviam de O.; Lobato, Raquel V.; Orlando, Débora R.; Borges, Bruno D.B.; de Sousa, Raimundo V.

2017-01-01

This study aimed to evaluate the effects of β-glucan ingestion (Saccharomyces cerevisiae) on the plasmatic levels of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10), alveolar bone loss, and pancreatic β-cell function (HOMA-BF) in diabetic rats with periodontal disease (PD). Besides, intestinal morphology was determined by the villus/crypt ratio. A total of 48 Wistar rats weighing 203 ± 18 g were used. Diabetes was induced by the intraperitoneal injection of streptozotocin (80 mg/kg) and periodontal inflammation, by ligature. The design was completely randomized in a factorial scheme 2 × 2 × 2 (diabetic or not, with or without periodontitis, and ingesting β-glucan or not). The animals received β-glucan by gavage for 28 days. Alveolar bone loss was determined by scanning electron microscopy (distance between the cementoenamel junction and alveolar bone crest) and histometric analysis (bone area between tooth roots). β-glucan reduced plasmatic levels of TNF-α in diabetic animals with PD and of IL-10 in animals with PD (p < 0.05). β-glucan reduced bone loss in animals with PD (p < 0.05). In diabetic animals, β-glucan improved β-cell function (p < 0.05). Diabetic animals had a higher villus/crypt ratio (p < 0.05). In conclusion, β-glucan ingestion reduced the systemic inflammatory profile, prevented alveolar bone loss, and improved β-cell function in diabetic animals with PD. PMID:28906456

Abutment height influences the effect of platform switching on peri-implant marginal bone loss.

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Galindo-Moreno, Pablo; León-Cano, Ana; Monje, Alberto; Ortega-Oller, Inmaculada; O'Valle, Francisco; Catena, Andrés

2016-02-01

The purpose was to radiographically analyze and compare the marginal bone loss (MBL) between implants with different mismatching distance and to study the influence of the prosthetic abutment height on the MBL in association with the related mismatching distances. This retrospective study included 108 patients in whom 228 implants were placed, 180 with diameter of 4.5 mm and 48 with diameter of 5 mm. All patients received OsseoSpeed™ implants with internal tapered conical connection (Denstply Implants). Different mismatching distances were obtained, given that all implants were loaded with the same uni-abutment type (Lilac; Denstply Implants). Data were gathered on age, gender, bone substratum, smoking habits, previous history of periodontitis, and prosthetic features. MBL was analyzed radiographically at 6 and 18 months post-loading. Mixed linear analysis of mesial and distal MBL values yielded significant effects of abutment, implant diameter, follow-up period, bone substratum, smoking, and abutment × time interaction. MBL was greater at 18 vs. 6 months, for short vs. long abutments, for grafted vs. pristine bone, for a heavier smoking habit, and for implants with a diameter of 5.0 vs. 4.5 mm. Greater mismatching does not minimize the MBL; abutment height, smoking habit, and bone substratum may play a role in the MBL over the short- and medium term. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bone turnover markers in patients with type 1 Gaucher disease

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Gaetano Giuffrida

2012-11-01

Full Text Available Bone complications occur frequently in Gaucher disease (GD and reduce the quality of life of these patients. Skeletal involvement is an important indication for treatment to ameliorate symptoms and reduce the risk of irreversible and debilitating disease. Bone biomarkers have been used to assess disease status and the response to therapy in a number of bone disorders. Here, we examine the literature for evidence of abnormalities in bone turnover markers in patients with type 1 GD to assess whether they might be useful for the assessment of bone involvement in GD. We have found that bone biomarkers in GD show highly variable results which do not currently support their routine use for clinical assessment of bone status, as an indication for therapy initiation, or for monitoring the response to therapy. A greater understanding of bone markers and their relation to the bone manifestations of GD is required.

Arthroscopic Bankart repair and subscapularis augmentation: an alternative technique treating anterior shoulder instability with bone loss.

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Maiotti, Marco; Russo, Raffaele; Zanini, Antonio; Schröter, Steffen; Massoni, Carlo; Bianchedi, Diana

2016-06-01

This study presents the preliminary results of a new arthroscopic technique consisting of the association of 2 procedures, capsulolabral repair and subscapularis augmentation tenodesis, in the treatment of traumatic anterior shoulder instability with both glenoid bone loss and a Hill-Sachs lesion. Eighty-nine patients engaged in sports were enrolled in this retrospective case-series study with 2 to 5 years' follow-up. All patients underwent a computed tomography scan to assess the percentage of glenoid bone loss by the Pico method. A prior stabilization procedure had failed in 20 patients, who were then segregated into a different group. Visual analog scale (VAS), Rowe, and American Shoulder and Elbow Surgeons (ASES) scores were used to assess the results. Only 3 of 89 patients had a post-traumatic redislocation. The mean length of follow-up was 31.5 months (range, 25-60 months). The VAS, Rowe, and ASES scores showed significant improvements: The VAS score decreased from a mean of 3.1 to 0.5 (P = .0157), the Rowe score increased from 58.9 to 94.1 (P = .0215), and the ASES score increased from 68.5 to 95.5 (P = .0197). The mean deficit of external rotation was 6° with the arm at the side of the trunk, and the mean deficit was 3° with the arm in 90° of abduction. The described procedure is a reproducible and effective technique used to restore joint stability in patients engaged in sports who have incurred anterior recurrent shoulder dislocation associated with glenoid bone loss (Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Genistein suppresses Prevotella intermedia lipopolysaccharide-induced inflammatory response in macrophages and attenuates alveolar bone loss in ligature-induced periodontitis.

Science.gov (United States)

Choi, Eun-Young; Bae, Seung Han; Ha, Min Hee; Choe, So-Hui; Hyeon, Jin-Yi; Choi, Jeom-Il; Choi, In Soon; Kim, Sung-Jo

2016-02-01

Genistein is a major isoflavone subclass of flavonoids found in soybean and a potent tyrosine kinase inhibitor. The present study aimed to assess the effect of genistein on the production of proinflammatory mediators in murine macrophages stimulated with lipopolysaccharide (LPS) isolated from Prevotella intermedia, a pathogen associated with different forms of periodontal disease, and to evaluate its possible influence on alveolar bone loss in ligature-induced periodontitis using micro-computed tomography (micro-CT) analysis as well. LPS was isolated from P. intermedia ATCC 25611 by using the standard hot phenol-water method. Culture supernatants were analyzed for nitric oxide (NO) and interleukin-6 (IL-6). Inducible NO synthase (iNOS) protein expression was evaluated by immunoblot analysis. Real-time PCR was carried out to measure iNOS and IL-6 mRNA expression. In addition, effect of genistein on alveolar bone loss was evaluated in a rat model of experimental periodontitis using micro-CT analysis. Genistein significantly attenuated P. intermedia LPS-induced production of iNOS-derived NO and IL-6 with attendant decrease in their mRNA expression in RAW264.7 cells. In addition, when genistein was administered to rats, decreases in alveolar bone height and bone volume fraction induced by ligature placement were significantly inhibited. Genistein administration also prevented ligature-induced alterations in the microstructural parameters of trabecular bone, including trabecular thickness, trabecular separation, bone mineral density and structure model index. While additional studies are required, we suggest that genistein could be utilized for the therapy of human periodontitis in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

β-Glucans (Saccharomyces cereviseae) Reduce Glucose Levels and Attenuate Alveolar Bone Loss in Diabetic Rats with Periodontal Disease

Science.gov (United States)

2015-01-01

The objective of this study was to assess the effects of oral ingestion of β-glucans isolated from Saccharomyces cereviseae on the metabolic profile, expression of gingival inflammatory markers and amount of alveolar bone loss in diabetic rats with periodontal disease. Diabetes mellitus was induced in 48 Wistar rats by intraperitoneal injection of streptozotocin (80 mg/kg). After confirming the diabetes diagnosis, the animals were treated with β-glucans (by gavage) for 28 days. On the 14th day of this period, periodontal disease was induced using a ligature protocol. β-glucans reduced the amount of alveolar bone loss in animals with periodontal disease in both the diabetic and non-diabetic groups (p periodontal disease (p periodontal disease (p periodontal effects in diabetic rats with periodontal disease. PMID:26291983

Fine-grained entanglement loss along renormalization-group flows

International Nuclear Information System (INIS)

Latorre, J.I.; Rico, E.; Luetken, C.A.; Vidal, G.

2005-01-01

We explore entanglement loss along renormalization group trajectories as a basic quantum information property underlying their irreversibility. This analysis is carried out for the quantum Ising chain as a transverse magnetic field is changed. We consider the ground-state entanglement between a large block of spins and the rest of the chain. Entanglement loss is seen to follow from a rigid reordering, satisfying the majorization relation, of the eigenvalues of the reduced density matrix for the spin block. More generally, our results indicate that it may be possible to prove the irreversibility along renormalization group trajectories from the properties of the vacuum only, without need to study the whole Hamiltonian

Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

Energy Technology Data Exchange (ETDEWEB)

Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T. [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India); Wani, Mohan R., E-mail: mohanwani@nccs.res.in [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India)

2010-09-03

Research highlights: {yields} IL-3 inhibits receptor activator of NF-{kappa}B ligand (RANKL)-induced osteoclastogenesis. {yields} IL-3 inhibits RANKL-induced JNK activation. {yields} IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. {yields} IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. {yields} IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-{kappa}B (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

International Nuclear Information System (INIS)

Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T.; Wani, Mohan R.

2010-01-01

Research highlights: → IL-3 inhibits receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. → IL-3 inhibits RANKL-induced JNK activation. → IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. → IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. → IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-κB (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

Tissue-specific expression of Sprouty1 in mice protects against high-fat diet-induced fat accumulation, bone loss and metabolic dysfunction.

Science.gov (United States)

Urs, Sumithra; Henderson, Terry; Le, Phuong; Rosen, Clifford J; Liaw, Lucy

2012-09-28

We recently characterised Sprouty1 (Spry1), a growth factor signalling inhibitor as a regulator of marrow progenitor cells promoting osteoblast differentiation at the expense of adipocytes. Adipose tissue-specific Spry1 expression in mice resulted in increased bone mass and reduced body fat, while conditional knockout of Spry1 had the opposite effect with decreased bone mass and increased body fat. Because Spry1 suppresses normal fat development, we tested the hypothesis that Spry1 expression prevents high-fat diet-induced obesity, bone loss and associated lipid abnormalities, and demonstrate that Spry1 has a long-term protective effect on mice fed a high-energy diet. We studied diet-induced obesity in mice with fatty acid binding promoter-driven expression or conditional knockout of Spry1 in adipocytes. Phenotyping was performed by whole-body dual-energy X-ray absorptiometry, microCT, histology and blood analysis. In conditional Spry1-null mice, a high-fat diet increased body fat by 40 %, impaired glucose regulation and led to liver steatosis. However, overexpression of Spry1 led to 35 % (P < 0·05) lower body fat, reduced bone loss and normal metabolic function compared with single transgenics. This protective phenotype was associated with decreased circulating insulin (70 %) and leptin (54 %; P < 0·005) compared with controls on a high-fat diet. Additionally, Spry1 expression decreased adipose tissue inflammation by 45 %. We show that conditional Spry1 expression in adipose tissue protects against high-fat diet-induced obesity and associated bone loss.

Combined effects of soy isoflavone and fish oil on ovariectomy-induced bone loss in mice.

Science.gov (United States)

Uchida, Raina; Chiba, Hiroshige; Ishimi, Yoshiko; Uehara, Mariko; Suzuki, Kazuharu; Kim, Hyounju; Matsumoto, Akiyo

2011-07-01

Both soy isoflavone and n-3 polyunsaturated fatty acids are known to reduce the levels of bone-resorbing cytokines; however, the synergistic effects of these food ingredients have not been examined yet. This study was performed to elucidate the effect of concomitant intake of soy isoflavone and fish oil on bone mass in ovariectomized mice. Eight-week-old ddY female mice were subjected to ovariectomy (OVX) or sham surgery, and then fed an AIN-93G with safflower oil (So) as a control lipid source, isoflavone-supplemented safflower oil (So + I), fish oil instead of safflower oil (Fo) or isoflavone-supplemented fish oil (Fo + I) for 4 weeks. Femoral bone mineral density was significantly decreased by OVX; however, this decrease was inhibited by the intake of isoflavone and/or fish oil. Histomorphometric analyses showed that bone volume and trabecular thickness in the distal femoral trabecular bone were significantly lower in the So group than in the sham group, but those were restored in the Fo + I groups. The number of osteoclasts was significantly decreased by isoflavone intake. The increased rate of bone resorption after OVX was inhibited by isoflavone and/or fish oil. The serum concentration of tumor necrosis factor alpha was increased after OVX, but was significantly lower with the combination of isoflavone with fish oil than isoflavone or fish oil alone. The results of this study indicated that the intakes of soy isoflavone and/or fish oil might have ameliorating effects on bone loss due to OVX. Further, the concomitant intake of soy isoflavone and fish oil at a low dose showed better effects on cytokines related with bone resorption.

Effects of metformin on inflammation, oxidative stress, and bone loss in a rat model of periodontitis.

Science.gov (United States)

Araújo, Aurigena Antunes de; Pereira, Aline de Sousa Barbosa Freitas; Medeiros, Caroline Addison Carvalho Xavier de; Brito, Gerly Anne de Castro; Leitão, Renata Ferreira de Carvalho; Araújo, Lorena de Souza; Guedes, Paulo Marcos Matta; Hiyari, Sarah; Pirih, Flávia Q; Araújo Júnior, Raimundo Fernandes de

2017-01-01

To evaluate the effects of metformin (Met) on inflammation, oxidative stress, and bone loss in a rat model of ligature-induced periodontitis. Male albino Wistar rats were divided randomly into five groups of twenty-one rats each, and given the following treatments for 10 days: (1) no ligature + water, (2) ligature + water, (3) ligature + 50 mg/kg Met, (4) ligature + 100 mg/kg Met, and (5) ligature + 200 mg/kg Met. Water or Met was administered orally. Maxillae were fixed and scanned using Micro-computed Tomography (μCT) to quantitate linear and bone volume/tissue volume (BV/TV) volumetric bone loss. Histopathological characteristics were assessed through immunohistochemical staining for MMP-9, COX-2, the RANKL/RANK/OPG pathway, SOD-1, and GPx-1. Additionally, confocal microscopy was used to analyze osteocalcin fluorescence. UV-VIS analysis was used to examine the levels of malondialdehyde, glutathione, IL-1β and TNF-α from gingival tissues. Quantitative RT-PCR reaction was used to gene expression of AMPK, NF-κB (p65), and Hmgb1 from gingival tissues. Significance among groups were analysed using a one-way ANOVA. A p-value of ploss after 50 mg/kg Met compared to the ligature and Met 200 mg/kg groups. The same pattern was observed volumetrically in BV/TV and decreased osteoclast number (ploss in ligature-induced periodontitis in rats.

The bisphosphonate zoledronate prevents vertebral bone loss in mature estrogen-deficient rats as assessed by micro-computed tomography

Directory of Open Access Journals (Sweden)

Glatt M.

2001-01-01

Full Text Available The effect of long-term treatment with the bisphosphonate zoledronate on vertebral bone architecture was investigated in estrogen-deficient mature rats. 4-month-old rats were ovariectomized and development of cancellous osteopenia was assessed after 1 year. The change of bone architectural parameters was determined with a microtomographic instrument of high resolution. After 1 year of estrogen-deficiency, animals lost 55% of vertebral trabecular bone in comparison to sham operated control animals. Trabecular number (Tb.N and trabecular thickness (Tb.Th were significantly reduced in ovariectomized animals, whereas trabecular separation (Tb.Sp, bone surface to volume fraction (BS/BV and trabecular bone pattern factor (TBPf were significantly increased, indicating a loss of architectural integrity throughout the vertebral body. 3 groups of animals were treated subcutaneously with zoledronate for 1 year with 0.3, 1.5 and 7.5 microgram/kg/week to inhibit osteoclastic bone degradation. Administration started immediately after ovariectomy and treatment dose-dependently prevented the architectural bone deterioration and completely suppressed the effects of estrogen deficiency at the higher doses. The results show that microtomographic determination of static morphometric parameters can be used to quantitate the effects of drugs on vertebral bone architecture in small laboratory animals and that zoledronate is highly effective in this rat model.

Neutrophil mobilization by surface-glycan altered Th17-skewing bacteria mitigates periodontal pathogen persistence and associated alveolar bone loss.

Directory of Open Access Journals (Sweden)

Rajendra P Settem

Full Text Available Alveolar bone (tooth-supporting bone erosion is a hallmark of periodontitis, an inflammatory disease that often leads to tooth loss. Periodontitis is caused by a select group of pathogens that form biofilms in subgingival crevices between the gums and teeth. It is well-recognized that the periodontal pathogen Porphyromonas gingivalis in these biofilms is responsible for modeling a microbial dysbiotic state, which then initiates an inflammatory response destructive to the periodontal tissues and bone. Eradication of this pathogen is thus critical for the treatment of periodontitis. Previous studies have shown that oral inoculation in mice with an attenuated strain of the periodontal pathogen Tannerella forsythia altered in O-glycan surface composition induces a Th17-linked mobilization of neutrophils to the gingival tissues. In this study, we sought to determine if immune priming with such a Th17-biasing strain would elicit a productive neutrophil response against P. gingivalis. Our data show that inoculation with a Th17-biasing T. forsythia strain is effective in blocking P. gingivalis-persistence and associated alveolar bone loss in mice. This work demonstrates the potential of O-glycan modified Tannerella strains or their O-glycan components for harnessing Th17-mediated immunity against periodontal and other mucosal pathogens.

Neutrophil mobilization by surface-glycan altered Th17-skewing bacteria mitigates periodontal pathogen persistence and associated alveolar bone loss.

Science.gov (United States)

Settem, Rajendra P; Honma, Kiyonobu; Sharma, Ashu

2014-01-01

Alveolar bone (tooth-supporting bone) erosion is a hallmark of periodontitis, an inflammatory disease that often leads to tooth loss. Periodontitis is caused by a select group of pathogens that form biofilms in subgingival crevices between the gums and teeth. It is well-recognized that the periodontal pathogen Porphyromonas gingivalis in these biofilms is responsible for modeling a microbial dysbiotic state, which then initiates an inflammatory response destructive to the periodontal tissues and bone. Eradication of this pathogen is thus critical for the treatment of periodontitis. Previous studies have shown that oral inoculation in mice with an attenuated strain of the periodontal pathogen Tannerella forsythia altered in O-glycan surface composition induces a Th17-linked mobilization of neutrophils to the gingival tissues. In this study, we sought to determine if immune priming with such a Th17-biasing strain would elicit a productive neutrophil response against P. gingivalis. Our data show that inoculation with a Th17-biasing T. forsythia strain is effective in blocking P. gingivalis-persistence and associated alveolar bone loss in mice. This work demonstrates the potential of O-glycan modified Tannerella strains or their O-glycan components for harnessing Th17-mediated immunity against periodontal and other mucosal pathogens.

Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

Directory of Open Access Journals (Sweden)

Khayat Andre

2011-01-01

Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

Performance analysis for minimally nonlinear irreversible refrigerators at finite cooling power

Science.gov (United States)

Long, Rui; Liu, Zhichun; Liu, Wei

2018-04-01

The coefficient of performance (COP) for general refrigerators at finite cooling power have been systematically researched through the minimally nonlinear irreversible model, and its lower and upper bounds in different operating regions have been proposed. Under the tight coupling conditions, we have calculated the universal COP bounds under the χ figure of merit in different operating regions. When the refrigerator operates in the region with lower external flux, we obtained the general bounds (0 present large values, compared to a relative small loss from the maximum cooling power. If the cooling power is the main objective, it is desirable to operate the refrigerator at a slightly lower cooling power than at the maximum one, where a small loss in the cooling power induces a much larger COP enhancement.

Weight loss on stimulant medication: how does it affect body composition and bone metabolism? – A prospective longitudinal study

Directory of Open Access Journals (Sweden)

Poulton Alison

2012-12-01

Full Text Available Abstract Objective Children treated with stimulant medication for attention deficit hyperactivity disorder (ADHD often lose weight. It is important to understand the implications of this during growth. This prospective study was designed to quantify the changes in body composition and markers of bone metabolism on starting treatment. Methods 34 children (29 boys aged 4.7 to 9.1 years newly diagnosed with ADHD were treated with dexamphetamine or methylphenidate, titrating the dose to optimise the therapeutic response. Medication was continued for as long as clinically indicated. Body composition and bone density (dual-energy X-ray absorptiometry were measured at baseline, 6 months and 3 years; changes were analysed in Z-scores based on data from 241 healthy, local children. Markers of bone turnover were measured at baseline, 3 months and 3 years. Results Fat loss of 1.4±0.96kg (total fat 5.7±3.6 to 4.3±3.1kg, p Conclusions Stimulant medication was associated with early fat loss and reduced bone turnover. Lean tissue including bone increased more slowly over 3 years of continuous treatment than would be expected for growth in height. There was long-term improvement in the proportion of central fat for height. This study shows that relatively minor reductions in weight on stimulant medication can be associated with long-term changes in body composition. Further study is required to determine the effects of these changes on adult health.

Sequential radionuclide bone imaging in avascular pediatric hip conditions

International Nuclear Information System (INIS)

Minikel, J.; Sty, J.; Simons, G.

1983-01-01

Radionuclide bone imaging was performed on six patients with various hip conditions. Initial bone images revealed diminished uptake of isotope /sup 99m/Tc-MDP in the capital femoral epiphysis. Following therapeutic intervention, repeat bone scans revealed normal uptake of /sup 99m/Tc-MDP in the capital femoral epiphysis. Subsequent radiographs revealed that avascular necrosis had not occurred. There are two types of avascularity: the potentially reversible, and the irreversible. Attempts should be made toward early recognition of the potentially reversible avascular insult. With early recognition, surgical reconstruction prior to osteophyte death may result in revascularization. If this can be accomplished, avascular necrosis can be avoided