bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsliding wear behaviour of HVOF sprayed conventional and nanostructured WC–12Co coatings at elevated temperatures
Authors: Yin B. , Zhou H. D. , Yi D. L. , Chen J. M. , Yan F. Y.
Published: October 2009

Conventional and nanostructured WC–12Co coatings were deposited on 1Cr18Ni9Ti substrate using high velocity oxy-fuel spraying. The surface roughness and microhardness of as sprayed coatings were measured, while the phase compositions and microstructures of WC–12Co feedstock powders and corresponding coatings were respectively analysed by means of X-ray diffraction and scanning electron microscopy. Moreover, the microsliding wear behaviour of both coatings sliding against Si3N4 ball from room temperature to 500°C was evaluated under unlubricated condition with an oscillating SRV tribotester. Results reveal that nanostructured WC–12Co coating not only had better wear-resistance than the conventional WC–12Co coating but also led to reduced wear of the Si3N4 counterpart under the same test condition, which could be attributed to the fine microstructure and improved mechanical properties of the nanostructured coating. The detailed wear mechanisms for both coatings have also been discussed.
Investigation of W–Mo alloyed layer synthesised by double glow plasma surface metallurgy
Authors: Huang J , Zhang P Z , Wu H Y , Bao W J
Published: October 2009

In the present study, the W–Mo alloyed layer was deposited on surface of Ti–6Al–4V. Microhardness and nanoindentation testing was used to evaluate mechanical properties of the alloyed layer. The tribological behaviour of W–Mo alloyed layer was estimated using a pin on disc tribometer. The friction coefficient and the wear mass were measured. Results showed that the tungsten and molybdenum content in the alloyed layer decreased gradually from surface to substrate, while the microhardness decreased gradually as the depth increased. The W–Mo alloyed layer had a smaller penetration depth and larger elastic modulus than the substrate. The friction coefficient of the W–Mo alloyed layer was lower than the substrate. The wear mass of W–Mo alloyed layer was one‐third lower than that of the substrate. It can be attributed to the higher hardness of the W–Mo alloyed layer surface which limited plastic deformation of the friction surface and decreased wear mass.
Nilotinib for the frontline treatment of Ph+ chronic myeloid leukemia
Authors: Rosti Gianantonio , Palandri Francesca , Castagnetti Fausto , Breccia Massimo , Levato Luciano , Gugliotta Gabriele , Capucci Adele , Cedrone Michele , Fava Carmen , Intermesoli Tamara , Cambrin Giovanna Rege , Stagno Fabio , Tiribelli Mario , Amabile Marilina , Luatti Simona , Poerio Angela , Soverini Simona , Testoni Nicoletta , Martinelli Giovanni , Alimena Giuliana , Pane Fabrizio , Saglio Giuseppe , Baccarani Michele ,   for the GIMEMA CML Working Party
Published: October 2009

Nilotinib has a higher binding affinity and selectivity for BCR-ABL with respect to imatinib and is an effective treatment of chronic myeloid leukemia (CML) after imatinib failure. In a phase 2 study, 73 early chronic-phase, untreated, Ph+ CML patients, received nilotinib at a dose of 400 mg twice daily. The primary endpoint was the complete cytogenetic response (CCgR) rate at 1 year. With a median follow-up of 15 months, the CCgR rate at 1 year was 96%, and the major molecular response rate 85%. Responses were rapid, with 78% CCgR and 52% major molecular response at 3 months. During the first year, the treatment was interrupted at least once in 38 patients (52%). The mean daily dose ranged between 600 and 800 mg in 74% of patients, 400 and 599 mg in 18% of patients, and was less than 400 mg in 8% of patients. Dose interruptions were mainly due to nonhematologic and biochemical side effects. Myelosuppression was irrelevant. One patient progressed to blastic crisis after 6 months; one went off-treatment for lipase increase grade 4 (no pancreatitis). Nilotinib is safe and very active in early chronic-phase CML. These data support a role for nilotinib for the frontline treatment of CML. This study was registered at ClinicalTrials.gov as NCT00481052.
Kisspeptin Signaling in the Brain
Authors: Oakley Amy E. , Clifton Donald K. , Steiner Robert A.
Published: October 2009

Kisspeptin (a product of the Kiss1 gene) and its receptor (GPR54 or Kiss1r) have emerged as key players in the regulation of reproduction. Mutations in humans or genetically targeted deletions in mice of either Kiss1 or Kiss1r cause profound hypogonadotropic hypogonadism. Neurons that express Kiss1/kisspeptin are found in discrete nuclei in the hypothalamus, as well as other brain regions in many vertebrates, and their distribution, regulation, and function varies widely across species. Kisspeptin neurons directly innervate and stimulate GnRH neurons, which are the final common pathway through which the brain regulates reproduction. Kisspeptin neurons are sexually differentiated with respect to cell number and transcriptional activity in certain brain nuclei, and some kisspeptin neurons express other cotransmitters, including dynorphin and neurokinin B (whose physiological significance is unknown). Kisspeptin neurons express the estrogen receptor and the androgen receptor, and these cells are direct targets for the action of gonadal steroids in both male and female animals. Kisspeptin signaling in the brain has been implicated in mediating the negative feedback action of sex steroids on gonadotropin secretion, generating the preovulatory GnRH/LH surge, triggering and guiding the tempo of sexual maturation at puberty, controlling seasonal reproduction, and restraining reproductive activity during lactation. Kisspeptin signaling may also serve diverse functions outside of the classical realm of reproductive neuroendocrinology, including the regulation of metastasis in certain cancers, vascular dynamics, placental physiology, and perhaps even higher-order brain function.
The Mammalian Ovary from Genesis to Revelation
Authors: Edson Mark A. , Nagaraja Ankur K. , Matzuk Martin M.
Published: October 2009

Two major functions of the mammalian ovary are the production of germ cells (oocytes), which allow continuation of the species, and the generation of bioactive molecules, primarily steroids (mainly estrogens and progestins) and peptide growth factors, which are critical for ovarian function, regulation of the hypothalamic-pituitary-ovarian axis, and development of secondary sex characteristics. The female germline is created during embryogenesis when the precursors of primordial germ cells differentiate from somatic lineages of the embryo and take a unique route to reach the urogenital ridge. This undifferentiated gonad will differentiate along a female pathway, and the newly formed oocytes will proliferate and subsequently enter meiosis. At this point, the oocyte has two alternative fates: die, a common destiny of millions of oocytes, or be fertilized, a fate of at most approximately 100 oocytes, depending on the species. At every step from germline development and ovary formation to oogenesis and ovarian development and differentiation, there are coordinated interactions of hundreds of proteins and small RNAs. These studies have helped reproductive biologists to understand not only the normal functioning of the ovary but also the pathophysiology and genetics of diseases such as infertility and ovarian cancer. Over the last two decades, parallel progress has been made in the assisted reproductive technology clinic including better hormonal preparations, prenatal genetic testing, and optimal oocyte and embryo analysis and cryopreservation. Clearly, we have learned much about the mammalian ovary and manipulating its most important cargo, the oocyte, since the birth of Louise Brown over 30 yr ago.
The Hexatonic and the Double Tonic
Authors: BaileyShea Matt
Published: October 2009

This article analyzes Hugo Wolf's Auf eine Christblume I and II in relation to Robert Bailey's concept of the “double-tonic complex.” These songs project an intricate pairing of D and F# tonalities that often result in various hexatonic relationships. My interpretation associates the D/F# complex with the central poetic subject: the Christmas rose. The article introduces Wolf's setting, reevaluates Bailey's idea, and offers an in-depth hermeneutic analysis of the two songs.
Humperdinck and Wagner
Authors: Leong Daphne
Published: October 2009

Building upon recent geometric models of metric states by Richard Cohn and Scott Murphy, this article proposes a complementary model that expands the metric states that can be considered, relates states by symmetries, and creates systems of such states. Application of the model to Engelbert Humperdinck's Hänsel und Gretel and Richard Wagner's Parsifal reveals metric-dramatic strategies common to the two operas: certain metric symmetries parallel certain dramatic ones.
Moved by Nothing
Authors: Margulis Elizabeth Hellmuth
Published: October 2009

This article explores the functions of silence in common-practice music, with an emphasis on the characteristics of perceived silence as distinct from notated and acoustic silence. Context is shown to guide listening in complex ways that enable the same acoustic silence, embedded in different musical surroundings, to encourage widely divergent perceptions. Five functions of silence are explored: silence as boundary, silence as interruption, silence as a revealer of the inner ear, silence as a promoter of meta-listening, and silence as a communicator. The article's account of silence emphasizes the active, participatory nature of music listening and addresses the implications for thought about music cognition and experience.
Continuous Harmonic Spaces
Authors: Callender Clifton
Published: October 2009

This article generalizes Ian Quinn's recent harmonic characterization of pitch-class sets in equal tempered spaces to chords drawn from continuous pitch and pitch-class spaces. Using the Fourier transform, chords of any real-valued pitches or pitch classes are represented by their spectra and located in a harmonic space of all possible chord spectra. Euclidean and angular distance metrics defined on chord spectra correlate strongly with common interval-based similarity measures such as IcVSIM and ANGLE. Thus, we can approximate these common measures of harmonic similarity in continuous environments, applying the corresponding harmonic intuitions to all possible chords of pitches and pitch classes in all possible tuning systems. This Fourier-based approach to harmony is used to compare the properties of twelve-note chords in Witold Lutosławski and Elliot Carter, to analyze the opening section of Gérard Grisey's Partiels, and to investigate the structural properties underlying the Z-relation (part of ongoing research with Rachel Hall).
Androgen receptor disruption increases the osteogenic response to mechanical loading in male mice
Authors: Callewaert Filip , Bakker Astrid , Schrooten Jan , Meerbeek Bart Van , Verhoeven Guido , Boonen Steven , Vanderschueren Dirk
Published: October 2009

In female mice, estrogen receptor-alpha (ERα) mediates the anabolic response of bone to mechanical loading. Whether ERα plays a similar role in the male skeleton and to what extent androgens and androgen receptor (AR) affect this response in males remain unaddressed. Therefore, we studied the adaptive response of in vivo ulna loading in AR-ERα knockout (KO) mice and corresponding male and female single KO and wild-type (WT) littermates using dynamic histomorphometry and immunohistochemistry. Additionally, cultured bone cells from WT and AR KO mice were subjected to mechanical loading by pulsating fluid flow in the presence or absence of testosterone. In contrast with female mice, ERα inactivation in male mice had no effect on the response to loading. Interestingly, loading induced significantly more periosteal bone formation in AR KO (+320%) and AR-ERα KO mice (+256%) compared with male WT mice (+114%) and had a stronger inhibitory effect on SOST/sclerostin expression in AR KO versus WT mice. In accordance, the fluid flow-induced nitric oxide production was higher in the absence of testosterone in bone cells from WT but not AR KO mice. In conclusion, AR but not ERα activation limits the osteogenic response to loading in male mice possibly via an effect on WNT signaling. © 2010 American Society for Bone and Mineral Research
Ferritin ferroxidase activity: A potent inhibitor of osteogenesis
Authors: Zarjou Abolfazl , Jeney Viktória , Arosio Paolo , Poli Maura , Zavaczki Erzsébet , Balla György , Balla József
Published: October 2009

Hemochromatosis is a known cause of osteoporosis, and iron overload has deleterious effects on bone. Although iron overload and its association with osteoporosis has long been recognized, the pathogenesis and exact role of iron have been undefined. Bone is an active tissue with constant remodeling capacity. Osteoblast (OB) development and maturation are under the influence of core binding factor α-1 (CBF-α1), which induces expression of OB-specific genes, including alkaline phosphatase, an important enzyme in early osteogenesis, and osteocalcin, a noncollagenous protein deposited within the osteoid. This study investigates the mechanism by which iron inhibits human OB activity, which in vivo may lead to decreased mineralization, osteopenia, and osteoporosis. We demonstrate that iron-provoked inhibition of OB activity is mediated by ferritin and its ferroxidase activity. We confirm this notion by using purified ferritin H-chain and ceruloplasmin, both known to possess ferroxidase activity that inhibited calcification, whereas a site-directed mutant of ferritin H-chain lacking ferroxidase activity failed to provide any inhibition. Furthermore, we are reporting that such suppression is not restricted to inhibition of calcification, but OB-specific genes such as alkaline phosphatase, osteocalcin, and CBF-α1 are all downregulated by ferritin in a dose-responsive manner. This study corroborates that iron decreases mineralization and demonstrates that this suppression is provided by iron-induced upregulation of ferritin. In addition, we conclude that inhibition of OB activity, mineralization, and specific gene expression is attributed to the ferroxidase activity of ferritin. © 2010 American Society for Bone and Mineral Research
Abdominal aortic calcification on vertebral morphometry images predicts incident myocardial infarction
Authors: Bolland Mark J , Wang Tom KM , van Pelt Niels C , Horne Anne M , Mason Barbara H , Ames Ruth W , Grey Andrew B , Ruygrok Peter N , Gamble Greg D , Reid Ian R
Published: October 2009

Abdominal aortic calcification (AAC) measured on spine X-rays is an established risk factor for cardiovascular disease. We investigated whether AAC assessed using vertebral morphometry and a recently developed scoring system (AAC-8) is reliable and associated with cardiovascular risk factors or events. A total of 1471 healthy postmenopausal women and 323 healthy middle-aged and older men participated in 5 and 2 year trials of calcium supplements, respectively. AAC-8 was assessed on vertebral morphometry images at baseline and follow-up. In addition, 163 men also had coronary artery calcification measured using computed tomography. Cardiovascular events during the trials were independently adjudicated. We found strong inter- and intrameasurer agreement for AAC-8 (κ > 0.87). The prevalence of AAC increased with age (p < .01) in women and in men. AAC was associated with many established cardiovascular risk factors, with serum calcium in women (p = .002) and with higher coronary calcium scores in men (p = .03). Estimated 5 year cardiovascular risk increased with increasing AAC-8 score (p < .001) in women and in men. The presence of AAC independently predicted myocardial infarction (MI) in women [hazards ratio (HR) = 2.30, p = .007] and men (HR = 5.32, p = .04), even after adjustment for estimated cardiovascular risk in women. In women, AAC independently predicted cardiovascular events (MI, stroke, or sudden death) (HR = 1.74, p = .007), and changes in AAC-8 score over time were associated with MI and cardiovascular events, even after adjustment for estimated cardiovascular risk. In summary, scoring AAC on vertebral morphometric scans is a reproducible method of assessing cardiovascular risk that independently predicts incident MI and cardiovascular events, even after taking into account traditional cardiovascular risk factors. © 2010 American Society for Bone and Mineral Research
The relationship between fractures and DXA measures of BMD in the distal femur of children and adolescents with cerebral palsy or muscular dystrophy
Authors: Henderson Richard C , Berglund Lisa M , May Ryan , Zemel Babette S , Grossberg Richard I , Johnson Julie , Plotkin Horacio , Stevenson Richard D , Szalay Elizabeth , Wong Brenda , Kecskemethy Heidi H , Harcke H Theodore
Published: October 2009

Children with limited or no ability to ambulate frequently sustain fragility fractures. Joint contractures, scoliosis, hip dysplasia, and metallic implants often prevent reliable measures of bone mineral density (BMD) in the proximal femur and lumbar spine, where BMD is commonly measured. Further, the relevance of lumbar spine BMD to fracture risk in this population is questionable. In an effort to obtain bone density measures that are both technically feasible and clinically relevant, a technique was developed involving dual-energy X-ray absorptiometry (DXA) measures of the distal femur projected in the lateral plane. The purpose of this study is to test the hypothesis that these new measures of BMD correlate with fractures in children with limited or no ability to ambulate. The relationship between distal femur BMD Z-scores and fracture history was assessed in a cross-sectional study of 619 children aged 6 to 18 years with muscular dystrophy or moderate to severe cerebral palsy compiled from eight centers. There was a strong correlation between fracture history and BMD Z-scores in the distal femur; 35% to 42% of those with BMD Z-scores less than −5 had fractured compared with 13% to 15% of those with BMD Z-scores greater than −1. Risk ratios were 1.06 to 1.15 (95% confidence interval 1.04–1.22), meaning a 6% to 15% increased risk of fracture with each 1.0 decrease in BMD Z-score. In clinical practice, DXA measure of BMD in the distal femur is the technique of choice for the assessment of children with impaired mobility. © 2010 American Society for Bone and Mineral Research
Estrogen augments shear stress–induced signaling and gene expression in osteoblast-like cells via estrogen receptor–mediated expression of β1-integrin
Authors: Yeh Chiuan-Ren , Chiu Jeng-Jiann , Lee Chih-I , Lee Pei-Ling , Shih Yu-Tsung , Sun Jui-Sheng , Chien Shu , Cheng Cheng-Kung
Published: October 2009

Estrogen and mechanical forces are positive regulators for osteoblast proliferation and bone formation. We investigated the synergistic effect of estrogen and flow-induced shear stress on signal transduction and gene expression in human osetoblast-like MG63 cells and primary osteoblasts (HOBs) using activations of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and expressions of c-fos and cyclooxygenase-2 (I) as readouts. Estrogen (17β-estradiol, 10 nM) and shear stress (12 dyn/cm2) alone induced transient phosphorylations of ERK and p38 MAPK in MG63 cells. Pretreating MG63 cells with 17β-estradiol for 6 hours before shearing augmented these shear-induced MAPK phosphorylations. Western blot and flow cytometric analyses showed that treating MG63 cells with 17β-estradiol for 6 hrs induced their β1-integrin expression. This estrogen-induction of β1-integrin was inhibited by pretreating the cells with a specific antagonist of estrogen receptor ICI 182,780. Both 17β-estradiol and shear stress alone induced c-fos and Cox-2 gene expressions in MG63 cells. Pretreating MG63 cells with 17β-estradiol for 6 hrs augmented the shear-induced c-fos and Cox-2 expressions. The augmented effects of 17β-estradiol on shear-induced MAPK phosphorylations and c-fos and Cox-2 expressions were inhibited by pretreating the cells with ICI 182,780 or transfecting the cells with β1-specific small interfering RNA. Similar results on the augmented effect of estrogen on shear-induced signaling and gene expression were obtained with HOBs. Our findings provide insights into the mechanism by which estrogen augments shear stress responsiveness of signal transduction and gene expression in bone cells via estrogen receptor–mediated increases in β1-integrin expression. © 2010 American Society for Bone and Mineral Research
Fluorescent risedronate analogues reveal bisphosphonate uptake by bone marrow monocytes and localization around osteocytes in vivo
Authors: Roelofs Anke J , Coxon Fraser P , Ebetino Frank H , Lundy Mark W , Henneman Zachary J , Nancollas George H , Sun Shuting , Blazewska Katarzyna M , Bala Joy Lynn F , Kashemirov Boris A , Khalid Aysha B , McKenna Charles E , Rogers Michael J
Published: October 2009

Bisphosphonates are effective antiresorptive agents owing to their bone-targeting property and ability to inhibit osteoclasts. It remains unclear, however, whether any non-osteoclast cells are directly affected by these drugs in vivo. Two fluorescent risedronate analogues, carboxyfluorescein-labeled risedronate (FAM-RIS) and Alexa Fluor 647–labeled risedronate (AF647-RIS), were used to address this question. Twenty-four hours after injection into 3-month-old mice, fluorescent risedronate analogues were bound to bone surfaces. More detailed analysis revealed labeling of vascular channel walls within cortical bone. Furthermore, fluorescent risedronate analogues were present in osteocytic lacunae in close proximity to vascular channels and localized to the lacunae of newly embedded osteocytes close to the bone surface. Following injection into newborn rabbits, intracellular uptake of fluorescently labeled risedronate was detected in osteoclasts, and the active analogue FAM-RIS caused accumulation of unprenylated Rap1A in these cells. In addition, CD14high bone marrow monocytes showed relatively high levels of uptake of fluorescently labeled risedronate, which correlated with selective accumulation of unprenylated Rap1A in CD14+ cells, as well as osteoclasts, following treatment with risedronate in vivo. Similar results were obtained when either rabbit or human bone marrow cells were treated with fluorescent risedronate analogues in vitro. These findings suggest that the capacity of different cell types to endocytose bisphosphonate is a major determinant for the degree of cellular drug uptake in vitro as well as in vivo. In conclusion, this study shows that in addition to bone-resorbing osteoclasts, bisphosphonates may exert direct effects on bone marrow monocytes in vivo. © 2010 American Society for Bone and Mineral Research
Circulating fibronectin affects bone matrix, whereas osteoblast fibronectin modulates osteoblast function
Authors: Bentmann Anke , Kawelke Nina , Moss David , Zentgraf Hanswalter , Bala Yohann , Berger Irina , Gasser Juerg A , Nakchbandi Inaam A
Published: October 2009

The bone matrix is composed mostly of collagen, but the initial and continuous presence of fibronectin was found to be crucial for collagen matrix integrity in vitro. It has been assumed that osteoblasts produce the fibronectin required for bone matrix formation. Using transgenic mice, we conditionally deleted fibronectin in the osteoblasts and in the liver using the cre-loxP system. We also used mice with mutated fibronectin and conditionally deleted β1-integrin in osteoblasts to identify the receptor involved in fibronectin effects on osteoblasts. Conditional deletion of fibronectin in the differentiating osteoblasts [using the 2.3 kb collagen-α1(I) promoter] failed to show a decrease in fibronectin amount in the bone matrix despite evidence of successful deletion. Using these mice we established that osteoblast-derived fibronectin solely affects osteoblast function. This effect was not mediated by integrins that bind to the RGD motif. Conditional deletion of fibronectin in the liver showed a marked decrease in fibronectin content in the matrix associated with decreased mineral-to-matrix ratio and changed biomechanical properties but had no effect on osteoblasts or osteoclasts. In conclusion, osteoblast fibronectin affects osteoblasts function. This does not seem to be mediated by the RGD motif on fibronectin. In contrast, liver-derived fibronectin affects bone matrix properties without affecting osteoblast or osteoclast function. A novel role for liver-derived circulating fibronectin thus was defined and delineated from that of locally produced fibronectin. © 2010 American Society for Bone and Mineral Research
Knee and hip radiographic osteoarthritis predict total hip bone loss in older adults: A prospective study
Authors: Ding Changhai , Cicuttini Flavia , Boon Catrina , Boon Pip , Srikanth Velandai , Cooley Helen , Jones Graeme
Published: October 2009

The relationship between osteoarthritis (OA) and osteoporosis remains controversial. This study was designed to determine the association between hip and knee radiographic OA and change in total hip bone mineral density (BMD) over 2.6 years. A total of 867 population-based randomly selected subjects (mean age 62 years, range 51 to 80 years, and 49% female) were included. Hip and knee joint space narrowing (JSN, 0 to 3) and osteophytes (0 to 3) in both lower limbs was assessed using Altman's atlas. Total hip BMD was measured by dual-energy X-ray absorptiometry (DXA). We found that radiographic OA (score of JSN or osteophytes > 0) was common in this sample (hip 45%, knee 68%). In multivariable analyses, percentage change in total hip BMD per year was predicted by right and left hip axial JSN (β = –0.25% and –0.29% per grade, respectively, both p < .05), right hip superior femoral osteophytes (grades 2 and 3 versus 0: β = –1.60, p < .05), combined right and left knee tibiofemoral JSN (β = –0.06 per grade from grades 0 to 12, p < .05), and osteophytes (β = –0.06 per grade from grades 0 to 14, p < .05) independent of each other and joint pain. In conclusion, older subjects with radiographic hip and knee OA have higher total hip bone loss over 2.6 years regardless of symptoms, suggesting that consideration should be given to the monitoring of bone mass in these subjects. © 2010 American Society for Bone and Mineral Research.
A functional polymorphism in MMP1 could influence osteomyelitis development
Authors: Montes Angel Hugo , Valle-Garay Eulalia , Alvarez Victoria , Pevida Marta , García Pérez Eva , Paz Jose , Meana Alvaro , Asensi Victor
Published: October 2009

Osteomyelitis (OM) is a bone infection characterized by necrosis and new formation of bone. Because matrix metalloproteases (MMPs) play an important role in bone extracellular matrix remodeling, we investigated the role of some MMP polymorphisms in OM patients. A total of 118 OM patients and 300 blood donors were genotyped for the polymorphisms of MMP1 (−1607 1G/2G) and MMP13 (−77A/G). Levels of MMPs (−1, −2, −3, −8, -9, −10, and −13) and tissue inhibitors of metaloproteases (TIMP-1, -2, and -4) in serum and in human osteoblasts obtained from OM biopsies also were determined. The MMP1 (–1607 2G/2G) genotype was significantly more frequent among OM patients compared with controls [65.3% versus 33.7%, χ2 = 26.85, odds ratio (OR) = 3.24, 95% confidence interval (CI) 2.03–5.2, p < .0001]. The MMP1 2G allele also was more frequent in OM patients (73.3% versus 57.2%, χ2 = 37.76, OR = 2.75, 95% CI 1.96–3.85, p < .0001). Carriers of the 2G allele had significantly higher osteoblast MMP1 mRNA and MMP-1 serum levels than noncarriers (p < .04). Interleukin 1α (IL-1α) increased MMP-1 and -13 protein secretion and Ets1 mRNA expression by OM patients' osteoblasts. No association of the MMP13 (–77 A/G) polymorphism with OM was observed. The MMP1 (–1607 1G/2G) polymorphism might contribute to OM pathogenesis. This could be due to increased expression of MMP-1 by osteoblasts and is regulated by IL-1α. © 2010 American Society for Bone and Mineral Research
Association with replication between estrogen-related receptor γ (ESRRγ) Polymorphisms and bone phenotypes in women of European ancestry
Authors: Elfassihi Latifa , Giroux Sylvie , Bureau Alexandre , Laflamme Nathalie , Cole David EC , Rousseau François
Published: October 2009

Osteoporosis is a bone disease characterized by low bone mineral density (BMD), a highly heritable polygenic trait. Women are more prone than men to develop osteoporosis owing to a lower peak bone mass and accelerated bone loss at menopause. Lack of estrogen thus is a major risk factor for osteoporosis. In addition to having strong similarity to the estrogen receptor 1 (ESR1), the orphan nuclear estrogen-related receptor γ (ESRRγ) is widely expressed and shows overlap with ESR1 expression in tissues where estrogen has important physiologic functions. For these reasons, we have undertaken a study of ESRRγ sequence variants in association with bone measurements [heel quantitative ultrasound (QUS) by measurements of broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) and dual-energy X-ray absorptiometry (DXA) at the femoral neck (FN) and lumbar spine (LS)]. A silent variant was found to be associated with multiple bone measurements (LS, BUA, SOS, and SI), the p values ranging from .006 to .04 in a sample of 5144 Quebec women. The region of this variant was analyzed using the HapMap database and the Gabriel method to define a block of 20 kb. Using the Tagger method, eight TagSNPs were identified and genotyped in a sample of 1335 women. Four of these SNPs capture the five major block haplotypes. One SNP (rs2818964) and one haplotype were significantly associated with multiple bone measures. All SNPs involved in the associations were analyzed in two other sample sets with significant results in the same direction. These results suggest involvement of ESRRγ in the determination of bone density in women. © 2010 American Society for Bone and Mineral Research
Growth hormone regulates the balance between bone formation and bone marrow adiposity
Authors: Menagh Philip J , Turner Russell T , Jump Donald B , Wong Carmen P , Lowry Malcolm B , Yakar Shoshana , Rosen Clifford J , Iwaniec Urszula T
Published: October 2009

Cancellous bone decreases and bone marrow fat content increases with age. Osteoblasts and adipocytes are derived from a common precursor, and growth hormone (GH), a key hormone in integration of energy metabolism, regulates the differentiation and function of both cell lineages. Since an age-related decline in GH is associated with bone loss, we investigated the relationship between GH and bone marrow adiposity in hypophysectomized (HYPOX) rats and in mice with defects in GH signaling. HYPOX dramatically reduced body weight gain, bone growth and mineralizing perimeter, serum insulin-like growth factor 1 (IGF-1) levels, and mRNA levels for IGF-1 in liver and bone. Despite reduced body mass and adipocyte precursor pool size, HYPOX resulted in a dramatic increase in bone lipid levels, as reflected by increased bone marrow adiposity and bone triglyceride and cholesterol content. GH replacement normalized bone marrow adiposity and precursor pool size, as well as mineralizing perimeter in HYPOX rats. In contrast, 17β -estradiol, IGF-1, thyroxine, and cortisone were ineffective. Parathyroid hormone (PTH) reversed the inhibitory effects of HYPOX on mineralizing perimeter but had no effect on adiposity. Finally, bone marrow adiposity was increased in mice deficient in GH and IGF-1 but not in mice deficient in serum IGF-1. Taken together, our findings indicate that the reciprocal changes in bone and fat mass in GH signaling-deficient rodents are not directly coupled with one another. Rather, GH enhances adipocyte as well as osteoblast precursor pool size. However, GH increases osteoblast differentiation while suppressing bone marrow lipid accumulation. © 2010 American Society for Bone and Mineral Research
Microdamage repair and remodeling requires mechanical loading
Authors: Waldorff Erik I , Christenson Katya B , Cooney Laura A , Goldstein Steven A
Published: October 2009

Bone remodeling is necessary to avoid microdamage accumulation, which could lead to whole-bone failure. Previous studies have shown that this bone-repair mechanism is triggered by osteocyte apoptosis. Through the use of a rodent hindlimb suspension model and tibial four-point bending model, the effects of disuse on microdamage remodeling was examined. At day 0, male rats were assigned to one of three groups: weight bearing (WB), hindlimb suspension (HS), or hindlimb suspension with daily intermittent weight bearing following damage-inducing loading (HW). Within each group, the rats were further divided into subgroups corresponding to three sacrifice time points [day 14 (WB and HS only), day 18, or day 35]. At day 14, animals were anesthetized, and their left tibiae underwent cyclic four-point bending to produce fatigue-induced microdamage. At sacrifice, the tibiae were examined using 3D micro-computed tomography (µCT), flow cytometry, and histologic and immunohistochemical stains. The results indicate that only the WB and HW groups had a significant increase in intracortical TRAP-positive resorption pits following damage induction, which was paralleled by a significant decrease in microdamage over time in combination with a shift in the osteoclast lineage owing to a decrease in monocytes. These results demonstrate that osteocyte apoptosis may be insufficient for repair of microdamage without the stimulation provided through physiologic loading. In addition, this potentially could have clinical implications for the current therapeutic paradigm for treating stress fractures, where extended non-weight bearing is employed. © 2010 American Society for Bone and Mineral Research
Identifying a molecular phenotype for bone marrow stromal cells with in vivo bone-forming capacity
Authors: Larsen Kenneth H , Frederiksen Casper M , Burns Jorge S , Abdallah Basem M , Kassem Moustapha
Published: October 2009

The ability of bone marrow stromal cells (BMSCs) to differentiate into osteoblasts is being exploited in cell-based therapy for repair of bone defects. However, the phenotype of ex vivo cultured BMSCs predicting their bone-forming capacity is not known. Thus we employed DNA microarrays comparing two human bone marrow stromal cell (hBMSC) populations: One is capable of in vivo heterotopic bone formation (hBMSC-TERT+Bone), and the other is not (hBMSC-TERT–Bone). Compared with hBMSC-TERT–Bone, the hBMSC-TERT+Bone cells had an increased overrepresentation of extracellular matrix genes (17% versus 5%) and a larger percentage of genes with predicted SP3 transcription factor–binding sites in their promoter region (21% versus 8%). On the other hand, hBMSC-TERT–Bone cells expressed a larger number of immune-response-related genes (26% versus 8%). In order to test for the predictive value of these markers, we studied the correlation between their expression levels in six different hBMSC-derived clones and the ability to form bone in vivo. We found a significant correlation for decorin, lysyl oxidase-like 4, natriuretic peptide receptor C, and tetranectin. No significant positive correlation was found for canonical osteoblastic markers Runx2, alkaline phosphatase, collagen type I, osteopontin, and bone sialoprotein. Prospective isolation of four additional hBMSC clones based on their expression levels of the molecular markers correlated with their in vivo bone-formation ability. In conclusion, our data suggest an in vitro molecular signature predictive for hBMSCs' in vivo bone-formation ability. Identifying more of these predictive markers would be very useful in the quality control of osteoblastic cells before use in therapy. © 2010 American Society for Bone and Mineral Research
Parathyroid hormone induction of cyclooxygenase-2 in murine osteoblasts: Role of the calcium-calcineurin-NFAT pathway
Authors: Huang Hechang , Chikazu Daichi , Voznesensky Olga S , Herschman Harvey R , Kream Barbara E , Drissi Hicham , Pilbeam Carol C
Published: October 2009

Murine MC3T3-E1 and MC-4 cells were stably transfected with −371/+70 bp of the murine cyclooxygenase-2 (COX-2) promoter fused to a luciferase reporter (Pluc371) or with Pluc371 carrying site-directed mutations. Mutations were made in (1) the cAMP response element (CRE) at −57/−52 bp, (2) the activating protein-1 (AP-1)–binding site at −69/−63 bp, (3) the nuclear factor of activated T-cells (NFAT)–binding site at −77/−73 bp, and (4) both the AP-1 and NFAT sites, which comprise a composite consensus sequence for NFAT/AP-1. Single mutation of CRE, AP-1, or NFAT sites decreased parathyroid hormone (PTH)–stimulated COX-2 promoter activity 40% to 60%, whereas joint mutation of NFAT and AP-1 abrogated the induction. On electrophoretic mobility shift analysis, PTH stimulated binding of phosphorylated CREB to an oligonucleotide spanning the CRE and binding of NFATc1, c-Fos, and c-Jun to an oligonucleotide spanning the NFAT/AP-1 composite site. Mutation of the NFAT site was less effective than mutation of the AP-1 site in competing binding to the composite element, suggesting that cooperative interactions of NFATc1 and AP-1 are more dependent on NFAT than on AP-1. Both PTH and forskolin, an activator of adenylyl cyclase, stimulated NFATc1 nuclear translocation. PTH- and forskolin-stimulated COX-2 promoter activity was inhibited 56% to 80% by calcium chelation or calcineurin inhibitors and 60% to 98% by protein kinase A (PKA) inhibitors. These results indicate an important role for the calcium-calcineurin-NFAT signaling pathway in the PTH induction of COX-2 and suggest that cross-talk between the cAMP/PKA pathway and the calcium-calcineurin-NFAT pathway may play a role in other functions of PTH in osteoblasts. © 2010 American Society for Bone and Mineral Research
Variable-Temperature Fourier Transform Infrared Spectroscopic Investigations of Poly(3-Hydroxyalkanoates) and Perturbation-Correlation Moving-Window Two-Dimensional Correlation Analysis. Part II: Study of Poly(ε-Caprolactone) Homopolymer and a Poly(3-Hydroxybutyrate)—Poly(ε-Caprolactone) Blend
Authors: Unger Miriam , Morita Shigeaki , Sato Harumi , Ozaki Yukihiro , Siesler Heinz W.
Published: October 2009

In the present study, variable-temperature Fourier transform infrared (FT-IR) spectra of a poly(ε-caprolactone) (PCL) homopolymer and a poly(3-hydroxybutyrate) (PHB)-poly(ε-caprolactone) (PCL) blend were analyzed by generalized two-dimensional correlation spectroscopy (2DCOS) and perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy. The C=O stretching vibration bands of PCL and PHB were employed to explore the structural changes in the PCL homopolymer and the PHB–PCL blend during the heating process. For the melting of PCL homopolymer in the temperature range of 50 to 70 °C, we observed in the synchronous and asynchronous 2D correlation spectra one crystalline (1724 cm−1) and one amorphous (1737 cm−1) C=O stretching vibration band, which are also detectable in the one-dimensional FT-IR spectra. This result was also confirmed by PCMW2D correlation spectroscopy. During the heating process of the PHB–PCL blend in the temperature range 30–200 °C, the PCMW2D correlation analysis provided detailed information. Thus, in the synchronous PCMW2D correlation spectrum the melting of PCL was observed in the temperature region between 30 and 70 °C. The recrystallization of PHB in the blend in the temperature range 70–120 °C was accompanied by a shift of the C=O stretching band from higher wavenumber (1724 cm−1) corresponding to an imperfect crystalline state to the lower wavenumber (1721 cm−1) characteristic of a well-ordered crystalline state. In the temperature range 120–200 °C the melting process of PHB in the blend is captured by a sharp transition from the crystalline (1722 cm−1) to the amorphous (1747 cm−1) C=O stretching band.
Absorption Spectroscopy Measurements in Optically Dense Explosive Fireballs Using a Modeless Broadband Dye Laser
Authors: Glumac Nick
Published: October 2009

A modeless broadband dye laser is applied to probe inside optically dense fireballs generated by high explosives using single-shot, high resolution absorption spectroscopy. Despite attenuation of the main beam by 98%, high signal-to-noise ratio absorption spectra of Al, Ti, and AlO are readily obtained at resolutions of 0.007 nm, and luminosity from the fireball is strongly rejected. Detection limits for atomic species are less than 200 ppb. The method offers good time resolution of chemistry within the fireball, and scaling laws suggest that this technique should be valid in explosives tests at least up to the gram scale.
Thermodynamic Analysis of Reaction Equilibria in Ionic and Molecular Liquid Systems by High-Temperature Raman Spectroscopy
Authors: Kalampounias Angelos G. , Boghosian Soghomon
Published: October 2009

A formalism for correlating relative Raman band intensities with the stoichiometric coefficients, the equilibrium constant, and the thermodynamics of reaction equilibria in solution is derived. The proposed method is used for studying: (1) the thermal dissociation of molten KHSO4 in the temperature range 240–450 °C; (2) the dinuclear complex formation in molten TaCl5–AlCl3 mixtures at temperatures between 125 and 235 °C. The experimental and calculational procedures for exploiting the temperature-dependent Raman band intensities in the molten phase as well as (if applicable) in the vapors thereof are described and used for determining the enthalpy of the equilibria: (1) 2HSO4−( l) ↔ S2O72–( l) + H2O( g), Δ H0 = 64.9 ± 2.9 kJ mol−1; and (2) 1/2Ta2Cl10( l) + 1/2Al2Cl6( l) ↔ TaAlCl8( l), Δ H0 = −12.1 £ 1.5 kJ mol−1.
Characterization of Chemical Bonding in Ion-Implanted Polymers by Means of Mid-Infrared Reflectivity
Authors: Ivanov Victor G. , Hadjichristov Georgi , Faulques Eric
Published: October 2009

An optical approach for structural characterization of the modified surface layer in ion-implanted polymers is proposed. The mid-infrared reflectivity from the implanted surface is analyzed in terms of an oscillator dispersion model combined with the theory of differential reflection spectroscopy. The degree of destruction of a specific chemical bond is determined by the relative drop of the oscillator strengths associated with the corresponding vibrational modes. As an example, this methodology is applied to poly(methylmethacrylate) (PMMA) implanted with 50 keV silicon ions at fluences in the range 3 × 1014 to 1 × 1017 ions/cm2. The scission rates for the C=O, C–O–C, and C–H bonds, as well as the static dielectric constant of the ion-modified material, are calculated as a function of the ion fluence. Further, a lower-limit estimate of 120 nm for the thickness of the ion-modified layer is obtained.
Broadband Plasmon Waveguide Resonance Spectroscopy for Probing Biological Thin Films
Authors: Zhang Han , Orosz Kristina S. , Takahashi Hiromi , Saavedra S. Scott
Published: October 2009

A commercially available spectrometer has been modified to perform plasmon waveguide resonance (PWR) spectroscopy over a broad spectral bandwidth. When compared to surface plasmon resonance (SPR), PWR has the advantage of allowing measurements in both s- and p-polarizations on a waveguide surface that is silica or glass rather than a noble metal. Here the waveguide is a BK7 glass slide coated with silver and silica layers. The resonance wavelength is sensitive to the optical thickness of the medium adjacent to the silica layer. The sensitivity of this technique is characterized and compared with broadband SPR both experimentally and theoretically. The sensitivity of spectral PWR is comparable to that of spectral SPR for samples with refractive indices close to that of water. The hydrophilic surface of the waveguide allows supported lipid bilayers to be formed spontaneously by vesicle fusion; in contrast, the surface of an SPR chip requires chemical modification to create a supported lipid membrane. Broadband PWR spectroscopy should be a useful technique to study biointerfaces, including ligand binding to transmembrane receptors and adsorption of peripheral proteins on ligand-bearing membranes.
Tracing the Acetalization of Cyclohexanone in CO2-Expanded Alcohols by Attenuated Total Reflection Infrared Spectroscopy
Authors: Seki Tsunetake , Andanson Jean-Michel , Jutz Fabian , Baiker Alfons
Published: October 2009

The CO2-catalyzed acetalization is regarded as a promising alternative to the conventional acid-catalyzed method from a viewpoint of green chemistry (C. A. Eckert et al., Ind. Eng. Chem. Res. 43, 2605 (2004)). We have applied in situ attenuated total reflection infrared (ATR-IR) spectroscopy for elucidating and monitoring the acetalization of cyclohexanone in CO2-expanded ethylene glycol and methanol at 50 °C and 3 MPa. The ATR-IR spectra of the reaction mixtures periodically recorded with a ZnSe crystal demonstrate that ATR-IR spectroscopy is a practical tool for tracing the kinetics of acetalizations in situ. In addition, the rate of CO2 dissolution as well as CO2 solubility into the cyclohexanone–alcohol mixtures could be evaluated from the CO2-v3-antisymmetric stretching band. The ZnSe ATR crystal, however, was corroded during longer use under the acidic conditions realized by the dissolution of CO2 in the alcohols. In contrast, the corrosion did not occur when a Ge crystal was used instead of a ZnSe crystal, and therefore the application of a Ge ATR crystal is recommended for continuous long-term experiments with these media.
A Two-Layer Gold Surface with Improved Surface Enhancement for Spectro-Electrochemistry Using Surface-Enhanced Infrared Absorption Spectroscopy
Authors: Nowak C. , Luening C. , Knoll W. , Naumann R. L. C.
Published: October 2009

A two-layer gold surface is developed for use with surface-enhanced infrared absorption spectroscopy (SEIRAS) consisting of a conducting underlayer onto which Au nanoparticles (AuNPs) are grown by self-catalyzed electroless deposition. AuNPs are grown on protruding substructures of the 25 nm thin underlayer. The enhancement factor of the two-layer gold surface is controlled by the growth conditions. Cytochrome c adsorbed to a self-assembled monolayer of mercaptoethanol is used as a reference system. Under optimum conditions the absorbance of the amide I band is increased by a factor of 5 versus the classical SEIRAS surface. Reversible reduction/oxidation of cytochrome c on the two-layer gold surface is shown to take place by cyclic voltammetry.
Determination of Glucose and Cellobiose Dissolved in the Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate Using Fourier Transform Infrared Spectroscopy
Authors: Kiefer Johannes , Obert Katharina , Fries Jürgen , Bösmann Andreas , Wasserscheid Peter , Leipertz Alfred
Published: October 2009

The conversion of biogenic carbohydrate feedstock to chemicals or energy equivalents is a promising approach to solve the problem of limited fossil fuel reserves. Some concepts to accomplish these transformations are based on ionic liquids (ILs) due to their ability to dissolve biopolymers, such as cellulose, and even complex biopolymer mixtures, such as wood. However, concerning control of such conversions, a reliable tool for process analytics is required. In this paper we demonstrate the applicability of Fourier transform infrared (FT-IR) spectroscopy to perform quantitative concentration measurements of glucose and cellobiose as two examples of carbohydrates dissolved in the room-temperature ionic liquid [EMIM][OAc] (1-ethyl-3-methylimidazolium acetate). For this purpose, binary mixtures in the range 0–20 wt% have been studied. A previously developed method for the data analysis, which was based on the Beer–Lambert relation, has been universalized by employing empirical correlations between the measured quantity (i.e., extinction) and the carbohydrate concentration. In the entire spectral range under investigation (500–4000 cm−1) numerous individual wavenumbers have been identified, allowing quantitative measurements with high accuracy and precision.