Urinary deoxypyridinoline is a BMD-independent marker for prevalent vertebral fractures in postmenopausal women treated with glucocorticoid

SUMMARY

Urinary deoxypyridinoline (DPD) level was associated with prevalent vertebral fractures in glucocorticoid (GC)-treated postmenopausal women independently of lumbar spine bone mineral density (BMD).

INTRODUCTION

Bone metabolic indices are the potential predictors of bone fragility. However, their diagnostic efficiency for identifying the risk of GC-induced vertebral fractures is still unclear. We therefore evaluated whether bone metabolic indices would assess the risk of vertebral fractures in GC-treated women.

METHODS

One hundred seventy-five women treated with GC for more than 6 months were enrolled in this study.

RESULTS

Both premenopausal and postmenopausal women with vertebral fractures had significantly higher urinary DPD levels than those without vertebral fractures. When multivariable logistic regression analysis was performed with the presence of vertebral fractures as a dependent variable and each of DPD or osteocalcin level adjusted for age, weight, height, current and maximum doses of GC, duration of GC treatment, as well as lumbar spine BMD as an independent variable, DPD level was identified as a factor associated with the presence of vertebral fractures in postmenopausal women but not in premenopausal women.

CONCLUSION

Urinary DPD level was significantly associated with prevalent vertebral fractures in GC-treated postmenopausal women independently of lumbar spine BMD.

The Calcium-sensing Receptor (CaR) is involved in strontium ranelate-induced osteoblast differentiation and mineralization

Strontium ranelate is known to reduce fracture risk in osteoporotic patients by stimulating bone formation and suppressing bone resorption. However, the mechanism by which strontium exerts this beneficial effect on bone is unclear. We examined whether or not the calcium-sensing receptor (CaR), which is activated by divalent cations including Sr (2+), is involved in this mechanism. Both strontium ranelate and strontium chloride dose-dependently stimulated phosphorylation of extracellular signal-regulated kinase (ERK) in Human Embryonic Kidney 293 cells transiently transfected with the human CaR. Strontium ranelate also dose- and time-dependently stimulated phosphorylation of ERK in mouse osteoblastic MC3T3-E1 cells expressing the CaR endogenously. Strontium ranelate increased mRNA expression of osteocalcin and bone morphogenetic protein-2 in MC3T3-E1 cells as well as mineralization and proliferation of the cells. Pretreatments of NPS2390, a CaR inhibitor, almost totally antagonized strontium ranelate-induced mineralization and proliferation of MC3T3-E1 cells. These findings indicate that strontium ranelate induces not only osteoblast proliferation but also its differentiation and mineralization by activating the CaR, and confirm that the therapeutic efficacy of strontium ranelate for osteoporosis may be partly mediated by the CaR.

Search for CP violation in the decays D(s)+ --> KS0pi+ and D(s)+ --> KS0K+

We have searched for CP violation in the charmed meson decays D((s))(+) --> K(S)(0)pi(+) and D((s))(+) --> K(S)(0)K(+) using 673 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. No evidence for CP violation is observed. We report the most sensitive CP asymmetry measurements to date for these decays: A(CP)(D(+)-->K(S)(0)pi(+)) = (-0.71 +/- 0.19 +/- 0.20)%, A(CP)(D(s)(+) --> K(S)(0)pi(+)) = (+5.45 +/- 2.50 +/- 0.33)%, A(CP)(D(+) --> K(S)(0)K(+)) = (-0.16 +/- 0.58 +/- 0.25)%, and A(CP)(D(s)(+) --> K(S)(0)K(+)) = (+0.12 +/- 0.36 +/- 0.22)%, where the first uncertainties are statistical and the second are systematic.

Radiation dose evaluation in 64-slice CT examinations with adult and paediatric anthropomorphic phantoms

The objective of this study was to evaluate the organ dose and effective dose to patients undergoing routine adult and paediatric CT examinations with 64-slice CT scanners and to compare the doses with those from 4-, 8- and 16-multislice CT scanners. Patient doses were measured with small (<7 mm wide) silicon photodiode dosemeters (34 in total), which were implanted at various tissue and organ positions within adult and 6-year-old child anthropomorphic phantoms. Output signals from photodiode dosemeters were read on a personal computer, from which organ and effective doses were computed. For the adult phantom, organ doses (for organs within the scan range) and effective doses were 8-35 mGy and 7-18 mSv, respectively, for chest CT, and 12-33 mGy and 10-21 mSv, respectively, for abdominopelvic CT. For the paediatric phantom, organ and effective doses were 4-17 mGy and 3-7 mSv, respectively, for chest CT, and 5-14 mGy and 3-9 mSv, respectively, for abdominopelvic CT. Doses to organs at the boundaries of the scan length were higher for 64-slice CT scanners using large beam widths and/or a large pitch because of the larger extent of over-ranging. The CT dose index (CTDI(vol)), dose-length product (DLP) and the effective dose values using 64-slice CT for the adult and paediatric phantoms were the same as those obtained using 4-, 8- and 16-slice CT. Conversion factors of DLP to the effective dose by International Commission on Radiological Protection 103 were 0.024 mSvmGy(-1)cm(-1) and 0.019 mSvmGy(-1)cm(-1) for adult chest and abdominopelvic CT scans, respectively.

Parathyroid hormone upregulates BMP-2 mRNA expression through mevalonate kinase and Rho kinase inhibition in osteoblastic MC3T3-E1 cells

It is well known that parathyroid hormone (PTH) possesses an anabolic effect on bone. However, the mechanisms are not fully elucidated. So far, it is unclear whether or not PTH could stimulate the expression of bone morphogenetic protein-2 (BMP-2), a strong mediator for bone formation. Growing evidence suggests that BMP-2 expression is regulated by the mevalonate pathway and Rho-associated protein kinase (ROK) activity. This study was performed to examine if PTH affects BMP-2 expression and to clarify its involvement of the mevalonate pathway. Osteoblastic MC3T3-E1 cells were treated with human PTH-(1-34) to determine BMP-2 mRNA expression levels by real-time PCR and to measure the ROK activity by the kinase assay. Incubation with 10 (-9)-10 (-8) M of hPTH-(1-34) for 6 h induced significant upregulation of BMP-2 mRNA levels in MC3T3-E1 cells. Short-term treatment of hPTH-(1-34) suppressed Rho kinase activity and mevalonate kinase mRNA levels. PTH-induced BMP-2 mRNA upregulation was selectively reversed by geranylgeranyl pyrophosphate (GGPP) pretreatment, but not by mevalonate pretreatment. These findings suggest that BMP-2 mRNA expression was upregulated by PTH in MC3T3-E1 cells mediated by mevalonate pathway suppression followed by ROK inhibition. We have now demonstrated for the first time that PTH stimulated BMP-2 mRNA expression via the mevalonate pathway and ROK in osteoblastic MC3T3-E1 cells.

Effects of chemical cross-linkers on caries-affected dentin bonding

The achievement of a strong and stable bond between composite resin and dentin remains a challenge in restorative dentistry. Over the past two decades, dental materials have been substantially improved, with better handling and bonding characteristics. However, little attention has been paid to the contribution of collagen structure/stability to bond strength. We hypothesized that the induction of cross-linking in dentin collagen improves dentin collagen stability and bond strength. This study investigated the effects of glutaraldehyde-and grape seed extract-induced cross-linking on the dentin bond strengths of sound and caries-affected dentin, and on the stability of dentin collagen. Our results demonstrated that the application of chemical cross-linking agents to etched dentin prior to bonding procedures significantly enhanced the dentin bond strengths of caries-affected and sound dentin. Glutaraldehyde and grape seed extract significantly increased dentin collagen stability in sound and caries-affected dentin, likely via distinct mechanisms.

Bone fragility in male glucocorticoid-induced osteoporosis is not defined by bone mineral density

Eighty-seven male Japanese subjects taking prednisolone > or = 5 mg for more than 6 months and 132 age- and body mass index (BMI)-matched control subjects were examined. Multiple regression analysis adjusted for age and BMI showed that spinal bone mineral density (BMD) in the prednisolone group was not associated with prevalent vertebral fractures (VFs).

INTRODUCTION

Glucocorticoid (GC) treatment is known to increase the risk for bone fractures. However, the association between VFs and BMD in GC-treated male patients remains unclear.

METHODS

Eighty-seven male subjects taking prednisolone > or = 5 mg for more than 6 months and 132 age- and BMI-matched control subjects were examined using lateral thoracic and lumbar spine radiographs and spine dual energy X-ray absorptiometry.

RESULTS

The presence of GC use was an independent risk factor for VFs adjusted for age and BMI (odds ratio 10.93, P < 0.001). By receiver operating characteristic analysis, the absolute BMD values for detecting VFs were higher and the sensitivity and specificity were lower in the GC group than in the control group (0.936 vs 0.825 g/cm(2) and 53.5% vs 74.0%, respectively). Multiple regression analysis adjusted for age and BMI showed that spinal BMD in the GC group was not associated with prevalent VFs, even after adding current and past maximum GC doses as independent variables.

CONCLUSIONS

These results show that lumbar BMD values are not associated with prevalent VFs in GC-treated male patients, suggesting that bone fragility in male GC users is affected by bone quality rather than by BMD.

Measurement of the differential branching fraction and forward-backward asymmetry for B --> K(*)l+l-

We study B --> K(*)l+l- decays (l = e, mu) based on a data sample of 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We report the differential branching fraction, isospin asymmetry, K* polarization, and the forward-backward asymmetry (A(FB)) as functions of q2 = M(ll)(2)c2. The fitted A(FB) spectrum exceeds the standard model expectation by 2.7 standard deviations. The measured branching fractions are B(B --> K*l+l-) = (10.7(-1.0)(+1.1) +/- 0.9) x 10(-7) and B(B --> Kl+l-) = (4.8(-0.4)(+0.5) +/- 0.3) x 10(-7), where the first errors are statistical and the second are systematic, with the muon to electron ratios R(K*) = 0.83 +/- 0.17 +/- 0.08 and R(K) = 1.03 +/- 0.19 +/- 0.06.

Inhibition of the mevalonate pathway rescues the dexamethasone-induced suppression of the mineralization in osteoblasts via enhancing bone morphogenetic protein-2 signal

We used dexamethasone (DEX)-treated osteoblastic MC3T3-E1 cells, and investigated the effects of an AMP-activated protein kinase activator, 5-aminoimidazole-4-carboxamide-1-beta- D-ribonucleoside (AICAR), a Rho-associated protein kinase inhibitor, fasudil hydrochrolide, as well as HMG-CoA reductase inhibitors, simvastatin and pitavastatin, all of which inhibit the mevalonate pathway. DEX (10(-8) M) significantly enhanced mRNA expression of bone morphogenetic protein (BMP)-2 antagonists, follistatin and Dan, and addition of each of 10 (-4) M AICAR, 10 (-5) M fasudil, 10(-6) M simvastatin, and 10(-6) M pitavastatin significantly reversed the enhancement in mRNA expression of follistatin and Dan and stimulated that of BMP-2 in the cells (p<0.05). DEX (10(-8) M) also significantly suppressed mineralization in the cells, and addition of each of these agents significantly reversed the suppression of mineralization (p<0.05). These findings suggest that the mevalonate pathway was involved in glucocorticoid-induced osteoblast dysfunction, and that its inhibition might promote bone formation through BMP-2 and alleviate glucocorticoid-induced osteoporosis.

Effect of cyclic mechanical loading on osteoclast recruitment in periodontal tissue

BACKGROUND AND OBJECTIVE

It is well accepted that cyclic mechanical loading induces osteoclastogenesis in periodontal tissue, but its molecular mechanisms are not well understood, in part because of a lack of appropriate models. In this study, we investigated a novel device that allows cyclic mechanical loading to be performed in a well-controlled manner. Furthermore, by employing this model, the effect of cyclic loading on osteoclast recruitment in the periodontal tissue was described.

MATERIAL AND METHODS

By using a newly developed device, the cyclic loading of 20 n (reference loading corresponding to the fracture hardness of dietary pellets) and two excessive loadings (i.e. 30 and 40 n) were applied to maxillary right molars in rats for up to 7 d, and osteoclast recruitment in the periodontal tissue was evaluated by analyzing relevant marker proteins using immunohistochemistry.

RESULTS

Osteoclastogenesis was induced by day 3 within alveolar bone subjected to a compression force of 30 n. With both 30 and 40 n loadings, cells that were positive to for tartrate-resistant acid phosphate, receptor activator of nuclear factor-kappaB ligand and osteoprotegerin were significantly increased in the alveolar bone/periodontal ligament in a time-dependent manner.

CONCLUSION

A new device was developed that allows various levels of cyclic mechanical loading to be exerted. By using this device in rats, early events of osteoclast recruitment in the periodontal tissues were observed with excessive loadings in a time-dependent manner, indicating the usefulness of this model.

Measurement of the Decay B_(s);(0)-->D_(s);(-)pi;(+) and Evidence for B_(s);(0)-->D_(s);(-/+)K;(+/-) in e;(+)e;(-) Annihilation at sqrt[s] approximately 10.87 GeV

We have studied B_(s);(0)-->D_(s);(-)pi;(+) and B_(s);(0)-->D_(s);(-/+)K;(+/-) decays using 23.6 fb;(-1) of data collected at the Upsilon(5S) resonance with the Belle detector at the KEKB e;(+)e;(-) collider. This highly pure B_(s);(0)-->D_(s);(-)pi;(+) sample is used to measure the branching fraction, B(B_(s);(0)-->D_(s);(-)pi;(+))=[3.67_(-0.33);(+0.35)(stat)-0.42+0.43(syst)+/-0.49(f_(s))]x10;(-3) (f_(s)=N_(B_(s);((*))B[over ]_(s);((*)))/N_(bb[over ])) and the fractions of B_(s);(0) event types at the Upsilon(5S) energy, in particular N_(B_(s);(*)B[over ]_(s);(*))/N_(B_(s);((*))B[over ]_(s);((*)))=(90.1_(-4.0);(+3.8)+/-0.2)%. We also determine the masses M(B_(s);(0))=(5364.4+/-1.3+/-0.7) MeV/c;(2) and M(B_(s);(*))=(5416.4+/-0.4+/-0.5) MeV/c;(2). In addition, we observe B_(s);(0)-->D_(s);(-/+)K;(+/-) decays with a significance of 3.5sigma and measure B(B_(s);(0)-->D_(s);(-/+)K;(+/-))=[2.4_(-1.0);(+1.2)(stat)+/-0.3(syst)+/-0.3(f_(s))]x10;(-4).

Measurement of the time-dependent CP asymmetries in B0-->K(S)(0)rho(0)gamma decays

We report the first measurement of time-dependent CP asymmetry in B(0)-->K(S)(0)rho(0)gamma decays based on 657 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy collider. We measure the CP-violating parameter S_{K_{S};{0}rho;{0}gamma}=0.11+/-0.33(stat)-0.09+0.05(syst) from a signal of 212+/-17 events. We also obtain the effective direct CP-violating parameter A{eff}=0.05+/-0.18(stat)+/-0.06(syst) for mK(S)0pi+pi- <1.8 GeV/c(2) and 0.6 GeV/c(2)<m pi+pi- <0.9 GeV/c2.

Two-year longitudinal changes in forearm cortical bone geometry in postmenopausal women with mild primary hyperparathyroidism without parathyroidectomy

Several studies suggest that mild PTH excess does not have any deteriorative effects on bone mineral density (BMD) in several-year-longitudinal studies of patients with mild primary hyperparathyroidism (pHPT) without parathyroidectomy (PTX). However, it remains unknown about the change in bone geometry in pHPT patients without PTX. We examined the longitudinal effects of mild PTH excess on cortical bone geometry in postmenopausal patients with mild pHPT without PTX by using peripheral quantitative computed tomography (pQCT), and we compared them with normal and hypoparathyroidism women. Nine postmenopausal female patients who were diagnosed as pHPT, six postmenopausal female patients with hypoparathyroidism (3 idiopathic and 3 postoperative), and thirty postmenopausal control subjects participated in this study. Radial volumetric (v) BMD and several bone geometry parameters were measured by pQCT at basal line and after 2 years. Cortical vBMD was significantly lower in pHPT group. Moreover, total area and periosteal circumferences were significantly higher in pHPT group. Total and cortical vBMD were significantly decreased after 2 years in control group. However, they were stable in pHPT group after 2-year follow-up. As for bone geometry, cortical thickness and area were also stable in pHPT group during 2-year follow-up, although they were significantly reduced in control group and hypoparathyroidism group. In conclusion, the present longitudinal study revealed that there were no significant changes in radial vBMD and cortical bone geometry in postmenopausal women with mild pHPT, whereas age-related thinning of cortical bone as well as decrease of vBMD were observed in the control and patients with hypoparathyroidism.

Evidence for neutral B meson decays to omegaK*0

We present the results of a study of the charmless vector-vector decay B0-->omegaK*0 with 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We measure the branching fraction to be B(B0-->omegaK*0) = [1.8+/-0.7(stat)+/-0.3(syst)]x 10(-6) with 3.0sigma significance. We also perform a helicity analysis of the omega and K*0 vector mesons, and obtain the longitudinal polarization fraction fL(B0-->omegaK*0) = 0.56+/-0.29(stat) -0.08(+0.18)(syst). Finally, we measure a large nonresonant branching fraction B[B0-->omegaK+pi(-);M Kpi in(0.755,1.250) GeV/c2] = [5.1+/-0.7(stat)+/-0.7(syst)]x 10(-6) with a significance of 9.5sigma.

Observation of a near-threshold enhancement in the e+e- -->Lambda+_(c)Lambda-_(c) cross section using initial-state radiation

We report a measurement of the exclusive e+ e- -->Lambda+_(c)Lambda-_(c) cross section as a function of center-of-mass energy near the Lambda+_(c)Lambda-_(c) threshold. A clear peak with a significance of 8.2sigma is observed in the Lambda+_(c)Lambda-_(c) invariant mass distribution just above threshold. With an assumption of a resonance origin for the observed peak, a mass and width of M=[4634 (+8)_(-7)(stat)(+5)_(-8)(syst)] MeV/c(2) and Gamma_(tot)=[92 (+40)_(-24)(stat)(+10)_(-21)(syst)] MeV are determined. The analysis is based on a study of events with initial-state-radiation photons in a data sample collected with the Belle detector at the Upsilon(4S) resonance and nearby continuum with an integrated luminosity of 695 fb(-1) at the KEKB asymmetric-energy e+ e- collider.

[Prosthetic aortic valve dysfunction due to projection of the left ventricular outflow septum]

Prosthetic valve dysfunction at the aortic position is generally caused by either pannus overgrowth or thrombus or both. We encountered a case with prosthetic valve dysfunction who had undergone an aortic valve replacement 4 years and 5 months before, receiving SJM-HP 21 mm. During the initial operation, a prosthetic valve was implanted parallel to the ventricular septum and slightly up toward the non-coronary sinus (Olin technique) because of a narrow aortic annulus. Before re-do surgery, Doppler echocardiography and cinefluoroscopy showed an incomplete opening of 1 leaflet of the prosthetic valve. At the re-do operation, it was observed that the movement of the anterior leaflet of the prosthetic valve was disturbed by the projecting ventricular septum. After the projecting ventricular septum was excised, SJM-regent 17 mm valve was implanted perpendicular to the septum at the supra-annular position. Postoperative course was uneventful. The postoperative aortic peak pressure gradient decreased to 25 mmHg by Doppler echocardiography.

Effects of natural cross-linkers on the stability of dentin collagen and the inhibition of root caries in vitro

PURPOSE

To evaluate the effects of dentin collagen modifications induced by various cross-linkers on the stability of collagen matrix and the inhibition of root caries.

MATERIALS AND METHODS

The following cross-linkers were tested: 5% glutaraldehyde (GA), 0.5% proanthocyanidin (PA), 0.625% genipin (GE). In the first experiment, cross-linker-treated demineralized human root dentin was digested with bacterial collagenase, centrifuged, and the supernatants were subjected to amino acid analysis to determine collagen content. The residues were analyzed by SDS-PAGE and hydroxyproline analysis. In the second experiment, bovine root surfaces were conditioned with phosphoric acid, treated with the cross-linkers, incubated with Streptococcus mutans and Lactobacillus acidophilus for 1 week and the root caries inhibition was evaluated with confocal microscopy. Lastly, the ability of the bacteria to colonize the root surface was evaluated. In this experiment slabs of bovine root were treated with the cross-linkers and incubated in a suspension of S. mutans and L. acidophilus. The slabs were washed, resuspended in water, glucose was added, and the pH measured.

RESULTS

While all collagen was digested with collagenase in the control groups, only a small proportion was solubilized in the GA-, PA-, and GE-treated groups. The root caries was significantly inhibited by treatment with PA or GA. Drops in pH in the cross-linker-treated groups were essentially the same as in the untreated group.

CONCLUSION

Naturally occurring cross-linkers, especially PA, could be used to modify root dentin collagen to efficiently stabilize collagen and to increase its resistance against caries.

Production of new charmoniumlike states in e+e- -->J/psiD*D[over](*) at sqrt[s] approximately 10.6 GeV

We report a study of the processes e+e- -->J/psiD*D[over](*). In J/psiD*D[over]* we observe a significant enhancement in the D*D[over]* invariant mass spectrum, which we interpret as a new charmoniumlike state and denote X(4160). The X(4160) parameters are M=(4156(-20)+25+/-15) MeV/c2 and Gamma=(139(-61)+111+/-21) MeV. We also report a new measurement of the X(3940) mass and width: M=(3942(-6)+7+/-6) MeV/c2 and Gamma=(37(-15)+26+/-8) MeV. The analysis is based on a 693 fb(-1) data sample recorded near the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric-energy collider.

Observation of B_(s)(0)-->phigamma and search for B_(s)(0)-->gammagamma decays at Belle

We search for the radiative penguin decays B_{s}{0}-->varphigamma and B_{s}{0}-->gammagamma in a 23.6 fb{-1} data sample collected at the Upsilon(5S) resonance with the Belle detector at the KEKB e{+}e{-} asymmetric-energy collider. We observe for the first time a radiative penguin decay of the B_{s}{0} meson in the B_{s}{0}-->varphigamma mode and we measure B(B_{s}{0}-->varphigamma)=(57_{-15}{+18}(stat)-11+12(syst))x10{-6}. No significant B_{s}{0}-->gammagamma signal is observed and we set a 90% confidence level upper limit of B(B_{s}{0}-->gammagamma)<8.7x10{-6}.