Quantitative computed tomography and cranial burr holes: a model to evaluate the quality of cranial reconstruction in humans.

PubMed

Worm, Paulo Valdeci; Ferreira, Nelson Pires; Ferreira, Marcelo Paglioli; Kraemer, Jorge Luiz; Lenhardt, Rene; Alves, Ronnie Peterson Marcondes; Wunderlich, Ricardo Castilho; Collares, Marcus Vinicius Martins

2012-05-01

Current methods to evaluate the biologic development of bone grafts in human beings do not quantify results accurately. Cranial burr holes are standardized critical bone defects, and the differences between bone powder and bone grafts have been determined in numerous experimental studies. This study evaluated quantitative computed tomography (QCT) as a method to objectively measure cranial bone density after cranial reconstruction with autografts. In each of 8 patients, 2 of 4 surgical burr holes were reconstructed with autogenous wet bone powder collected during skull trephination, and the other 2 holes, with a circular cortical bone fragment removed from the inner table of the cranial bone flap. After 12 months, the reconstructed areas and a sample of normal bone were studied using three-dimensional QCT; bone density was measured in Hounsfield units (HU). Mean (SD) bone density was 1535.89 (141) HU for normal bone (P < 0.0001), 964 (176) HU for bone fragments, and 453 (241) HU for bone powder (P < 0.001). As expected, the density of the bone fragment graft was consistently greater than that of bone powder. Results confirm the accuracy and reproducibility of QCT, already demonstrated for bone in other locations, and suggest that it is an adequate tool to evaluate cranial reconstructions. The combination of QCT and cranial burr holes is an excellent model to accurately measure the quality of new bone in cranial reconstructions and also seems to be an appropriate choice of experimental model to clinically test any cranial bone or bone substitute reconstruction.

Diagram of Calcium Movement in the Human Body

NASA Technical Reports Server (NTRS)

2002-01-01

This diagram shows the normal pathways of calcium movement in the body and indicates changes (green arrows) seen during preliminary space flight experiments. Calcium plays a central role because 1) it gives strength and structure to bone and 2) all types of cells require it to function normally. To better understand how and why weightlessness induces bone loss, astronauts have participated in a study of calcium kinetics -- that is, the movement of calcium through the body, including absorption from food, and its role in the formation and breakdown of bone.

Comparison of a novel bone-tendon allograft with a human dermis-derived patch for repair of chronic large rotator cuff tears using a canine model.

PubMed

Smith, Matthew J; Cook, James L; Kuroki, Keiichi; Jayabalan, Prakash S; Cook, Cristi R; Pfeiffer, Ferris M; Waters, Nicole P

2012-02-01

This study tested a bone-tendon allograft versus human dermis patch for reconstructing chronic rotator cuff repair by use of a canine model. Mature research dogs (N = 15) were used. Radiopaque wire was placed in the infraspinatus tendon (IST) before its transection. Three weeks later, radiographs showed IST retraction. Each dog then underwent 1 IST treatment: debridement (D), direct repair of IST to bone with a suture bridge and human dermis patch augmentation (GJ), or bone-tendon allograft (BT) reconstruction. Outcome measures included lameness grading, radiographs, and ultrasonographic assessment. Dogs were killed 6 months after surgery and both shoulders assessed biomechanically and histologically. BT dogs were significantly (P = .01) less lame than the other groups. BT dogs had superior bone-tendon, tendon, and tendon-muscle integrity compared with D and GJ dogs. Biomechanical testing showed that the D group had significantly (P = .05) more elongation than the other groups whereas BT had stiffness and elongation characteristics that most closely matched normal controls. Radiographically, D and GJ dogs showed significantly more retraction than BT dogs (P = .003 and P = .045, respectively) Histologically, GJ dogs had lymphoplasmacytic infiltrates, tendon degeneration and hypocellularity, and poor tendon-bone integration. BT dogs showed complete incorporation of allograft bone into host bone, normal bone-tendon junctions, and well-integrated allograft tendon. The bone-tendon allograft technique re-establishes a functional IST bone-tendon-muscle unit and maintains integrity of repair in this model. Clinical trials using this bone-tendon allograft technique are warranted. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Interspecies comparison of subchondral bone properties important for cartilage repair.

PubMed

Chevrier, Anik; Kouao, Ahou S M; Picard, Genevieve; Hurtig, Mark B; Buschmann, Michael D

2015-01-01

Microfracture repair tissue in young adult humans and in rabbit trochlea is frequently of higher quality than in corresponding ovine or horse models or in the rabbit medial femoral condyle (MFC). This may be related to differences in subchondral properties since repair is initiated from the bone. We tested the hypothesis that subchondral bone from rabbit trochlea and the human MFC are structurally similar. Trochlea and MFC samples from rabbit, sheep, and horse were micro-CT scanned and histoprocessed. Samples were also collected from normal and lesional areas of human MFC. The subchondral bone of the rabbit trochlea was the most similar to human MFC, where both had a relatively thin bone plate and a more porous and less dense character of subchondral bone. MFC from animals all displayed thicker bone plates, denser and less porous bone and thicker trabeculae, which may be more representative of older or osteoarthritic patients, while both sheep trochlear ridges and the horse lateral trochlea shared some structural features with human MFC. Since several cartilage repair procedures rely on subchondral bone for repair, subchondral properties should be accounted for when choosing animal models to study and test procedures that are intended for human cartilage repair. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Measurement of the normalized broadband ultrasound attenuation in trabecular bone by using a bidirectional transverse transmission technique

NASA Astrophysics Data System (ADS)

Lee, Kang Il

2015-01-01

A new method for measuring the normalized broadband ultrasound attenuation (nBUA) in trabecular bone by using a bidirectional transverse transmission technique was proposed and validated with measurements obtained by using the conventional transverse transmission technique. There was no significant difference between the nBUA measurements obtained for 14 bovine femoral trabecular bone samples by using the bidirectional and the conventional transverse transmission techniques. The nBUA measured by using the two transverse transmission techniques showed strong positive correlations of r = 0.87 to 0.88 with the apparent bone density, consistent with the behavior in human trabecular bone invitro. We expect that the new method can be usefully applied for improved accuracy and precision in clinical measurements.

[Remodeling simulation of human femur under bed rest and spaceflight circumstances based on three dimensional finite element analysis].

PubMed

Yang, Wenting; Wang, Dongmei; Lei, Zhoujixin; Wang, Chunhui; Chen, Shanguang

2017-12-01

Astronauts who are exposed to weightless environment in long-term spaceflight might encounter bone density and mass loss for the mechanical stimulus is smaller than normal value. This study built a three dimensional model of human femur to simulate the remodeling process of human femur during bed rest experiment based on finite element analysis (FEA). The remodeling parameters of this finite element model was validated after comparing experimental and numerical results. Then, the remodeling process of human femur in weightless environment was simulated, and the remodeling function of time was derived. The loading magnitude and loading cycle on human femur during weightless environment were increased to simulate the exercise against bone loss. Simulation results showed that increasing loading magnitude is more effective in diminishing bone loss than increasing loading cycles, which demonstrated that exercise of certain intensity could help resist bone loss during long-term spaceflight. At the end, this study simulated the bone recovery process after spaceflight. It was found that the bone absorption rate is larger than bone formation rate. We advise that astronauts should take exercise during spaceflight to resist bone loss.

Dwarfism in Alaskan malamutes: a disease resembling metaphyseal dysplasia in human beings.

PubMed Central

Sande, R. D.; Alexander, J. E.; Spencer, G. R.; Padgett, G. A.; Davis, W. C.

1982-01-01

In a study of 300 Alaskan Malamutes, dwarfism was shown to be an autosomal recessive inherited disease with complete penetrance that resulted in disturbed endochondral bone formation. Osseous growth disturbance was manifest at the metaphyses of tubular bones. Clinical and radiographic changes were very similar to those of rickets, although appositional bone formation rates were normal. Serum calcium, phosphorus, and alkaline phosphatase were within normal limits. Urinary excretion of calcium, phosphate, and amino acids were normal. Excess matrix was formed in the zone of cartilage cell proliferation, and the matrix persisted in the growth plate. Normal stresses resulted in microfractures in the metaphyses with subsequent interference of vascular penetration into the zone of degenerated cartilage cells. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7065114

Generation of clinical grade human bone marrow stromal cells for use in bone regeneration

PubMed Central

Robey, Pamela G.; Kuznetsov, Sergei A.; Ren, Jiaqiang; Klein, Harvey G.; Sabatino, Marianna; Stroncek, David F.

2014-01-01

In current orthopaedic practice, there is a need to increase the ability to reconstruct large segments of bone lost due to trauma, resection of tumors and skeletal deformities, or when normal regenerative processes have failed such as in non-unions and avascular necrosis. Bone marrow stromal cells (BMSCs, also known as bone marrow-derived mesenchymal stem cells), when used in conjunction with appropriate carriers, represent a means by which to achieve bone regeneration in such cases. While much has been done at the bench and in pre-clinical studies, moving towards clinical application requires the generation of clinical grade cells. What is described herein is an FDA-approved cell manufacturing procedure for the ex vivo expansion of high quality, biologically active human BMSCs. PMID:25064527

High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats

PubMed Central

Kasai, Shunji; Ito, Akemi; Shindo, Kaori; Toyoshi, Tohru; Bando, Masahiro

2015-01-01

Oxidative stress affects bone turnover. Preventative effects of antioxidants such as vitamin E on reduced bone mineral density and fractures associated with aging, osteoporosis, and smoking have been examined in animals and humans. The effects of vitamin E (α-tocopherol; αT) on bone health have yielded conflicting and inconclusive results from animal studies. In this study, to determine the bone effects of αT, we investigated the in vivo effects of αT on the bone mineral density, bone mass, bone microstructure, bone resorption, and osteogenesis through peripheral quantitative computed tomography (pQCT) measurements, micro-computed tomography (micro-CT) analyses, and bone histomorphometry of lumbar vertebrae and femurs in normal female Wistar rats fed diets containing αT in different quantities (0, 30, 120, or 600 mg/kg diet) for 8 weeks. To validate our hypotheses regarding bone changes, we examined ovariectomized rats as an osteoporosis model and control sham-operated rats in parallel. As expected, ovariectomized rats had reduced bone mineral density in lumbar vertebrae and the distal metaphyses of their femurs, reduced bone mass and deteriorated microstructure of cancellous bones in the vertebral body and distal femur metaphyses, and reduced bone mass due to resorption-dominant enhanced bone turnover in secondary cancellous bones in these sites. In comparison, αT administered to normal rats, even at the highest dose, did not induce reduced bone mineral density of lumbar vertebrae and femurs or a reduced bone mass or fragile microstructure of cancellous bones of the vertebral body and distal femur metaphyses. Instead, αT-fed rats showed a tendency for an osteogenesis-dominant bone mass increase in secondary cancellous bones in the vertebral body, in which active bone remodeling occurs. Thus, αT consumption may have beneficial effects on bone health. PMID:26147575

Human osteocalcin and bone sialoprotein mediating osteomimicry of prostate cancer cells: role of cAMP-dependent protein kinase A signaling pathway.

PubMed

Huang, Wen-Chin; Xie, Zhihui; Konaka, Hiroyuki; Sodek, Jaro; Zhau, Haiyen E; Chung, Leland W K

2005-03-15

Osteocalcin and bone sialoprotein are the most abundant noncollagenous bone matrix proteins expressed by osteoblasts. Surprisingly, osteocalcin and bone sialoprotein are also expressed by malignant but not normal prostate epithelial cells. The purpose of this study is to investigate how osteocalcin and bone sialoprotein expression is regulated in prostate cancer cells. Our investigation revealed that (a) human osteocalcin and bone sialoprotein promoter activities in an androgen-independent prostate cancer cell line of LNCaP lineage, C4-2B, were markedly enhanced 7- to 12-fold in a concentration-dependent manner by conditioned medium collected from prostate cancer and bone stromal cells. (b) Deletion analysis of human osteocalcin and bone sialoprotein promoter regions identified cyclic AMP (cAMP)-responsive elements (CRE) as the critical determinants for conditioned medium-mediated osteocalcin and bone sialoprotein gene expression in prostate cancer cells. Consistent with these results, the protein kinase A (PKA) pathway activators forskolin and dibutyryl cAMP and the PKA pathway inhibitor H-89, respectively, increased or repressed human osteocalcin and bone sialoprotein promoter activities. (c) Electrophoretic mobility shift assay showed that conditioned medium-mediated stimulation of human osteocalcin and bone sialoprotein promoter activities occurs through increased interaction between CRE and CRE-binding protein. (d) Conditioned medium was found to induce human osteocalcin and bone sialoprotein promoter activities via increased CRE/CRE-binding protein interaction in a cell background-dependent manner, with marked stimulation in selected prostate cancer but not bone stromal cells. Collectively, these results suggest that osteocalcin and bone sialoprotein expression is coordinated and regulated through cAMP-dependent PKA signaling, which may define the molecular basis of the osteomimicry exhibited by prostate cancer cells.

Accumulation of rare earth elements in human bone within the lifespan.

PubMed

Zaichick, Sofia; Zaichick, Vladimir; Karandashev, Vasilii; Nosenko, Sergey

2011-02-01

For the first time, the contents of rare earth elements (REEs) in a rib bone of a healthy human were determined. The mean value of the contents of Ce, Dy, Er, Gd, La, Nd, Pr, Sm, Tb, and Yb (10 elements out of 17 total REEs), as well as the upper limit of means for Ho, Lu, Tm, and Y (4 elements) were measured in the rib bone tissue of 38 females and 42 males (15 to 55 years old) using inductively coupled plasma mass spectrometry (ICP-MS). We found age-related accumulation of REEs in the bone tissue of healthy individuals who lived in a non-industrial region. It was calculated that during a lifespan the content of REEs in a skeleton of non-industrial region residents may increase by one to two orders of magnitude. Using our results as indicative normal values and published data we estimated relative Gd accumulation in the bone tissue of patients according to magnetic resonance imaging with contrast agent and La accumulation in the bone tissue of patients receiving hemodialysis after treatment with lanthanum carbonate as a phosphate binder. It was shown that after such procedures contents of Gd and La in the bone tissue of patients are two to three orders of magnitude higher than normal levels. In our opinion, REEs incorporation may affect bone quality and health similar to other potentially toxic trace metals. The impact of elevated REEs content on bone physiology, biochemistry and morphology requires further investigation.

Bone Formation Rate in Experimental Disuse Osteoporosis in Monkeys

NASA Technical Reports Server (NTRS)

Cann, Christopher; Young, Donald R.

1976-01-01

Specific mechanisms underlying weightless and hypodynamic bone loss are obscure. A principal relationship which must be affected is the balance between bone formation and bone resorption rates. In order to better define the influence of those parameters on bone loss, and also to develop measurements in other species as a useful adjunct to human research, studies were undertaken with experimental monkeys. Tests were conducted with a total of 6 adult male monkeys, weighing 10-13 kg, and approximately 10-12 yrs. of age to evaluate specifically bone formation rate during the development of disuse osteoporosis and osteopenia. Three animals were restrained in a semi-recumbent position for six months; three animals served as normal caged controls. Food intake (Purina) was held relatively constant at 200g/day for each animal. Using a Norland Bone Mineral Analyzer, bone mineral losses of 3.5 to 6% were seen in the mid-shaft of the tibia and in the distal radius. Bone loss was confirmed radiographically, with observation of thinning of the proximal tibial cortex and trabeculae in the calcaneus. Bone formation rate was determined using standard Ca-47 kinetics under metabolic balance conditions. After six months of restraint, accretion was 7.2-13.2 mg Ca/kg/day, compared to 3.2-4.1 mg Ca/kg/day in caged controls and 3-8 mg Ca/kg/day in normal adult humans. Fecal and urine calcium was 25-40% higher in restrained animals than in controls. Dietary calcium absorption decreases during restraint, and calcium turnover increases, implying a rise in bone resorption rate concommitant with the observed rise in bone accretion rate. Further studies dealing specifically with bone resorption are underway to define this more fully.

Extended flow cytometry characterization of normal bone marrow progenitor cells by simultaneous detection of aldehyde dehydrogenase and early hematopoietic antigens: implication for erythroid differentiation studies

PubMed Central

Mirabelli, Peppino; Di Noto, Rosa; Lo Pardo, Catia; Morabito, Paolo; Abate, Giovanna; Gorrese, Marisa; Raia, Maddalena; Pascariello, Caterina; Scalia, Giulia; Gemei, Marica; Mariotti, Elisabetta; Del Vecchio, Luigi

2008-01-01

Background Aldehyde dehydrogenase (ALDH) is a cytosolic enzyme highly expressed in hematopoietic precursors from cord blood and granulocyte-colony stimulating factor mobilized peripheral blood, as well as in bone marrow from patients with acute myeloblastic leukemia. As regards human normal bone marrow, detailed characterization of ALDH+ cells has been addressed by one single study (Gentry et al, 2007). The goal of our work was to provide new information about the dissection of normal bone marrow progenitor cells based upon the simultaneous detection by flow cytometry of ALDH and early hematopoietic antigens, with particular attention to the expression of ALDH on erythroid precursors. To this aim, we used three kinds of approach: i) multidimensional analytical flow cytometry, detecting ALDH and early hematopoietic antigens in normal bone marrow; ii) fluorescence activated cell sorting of distinct subpopulations of progenitor cells, followed by in vitro induction of erythroid differentiation; iii) detection of ALDH+ cellular subsets in bone marrow from pure red cell aplasia patients. Results In normal bone marrow, we identified three populations of cells, namely ALDH+CD34+, ALDH-CD34+ and ALDH+CD34- (median percentages were 0.52, 0.53 and 0.57, respectively). As compared to ALDH-CD34+ cells, ALDH+CD34+ cells expressed the phenotypic profile of primitive hematopoietic progenitor cells, with brighter expression of CD117 and CD133, accompanied by lower display of CD38 and CD45RA. Of interest, ALDH+CD34- population disclosed a straightforward erythroid commitment, on the basis of three orders of evidences. First of all, ALDH+CD34- cells showed a CD71bright, CD105+, CD45- phenotype. Secondly, induction of differentiation experiments evidenced a clear-cut expression of glycophorin A (CD235a). Finally, ALDH+CD34- precursors were not detectable in patients with pure red cell aplasia (PRCA). Conclusion Our study, comparing surface antigen expression of ALDH+/CD34+, ALDH-/CD34+ and ALDH+/CD34- progenitor cell subsets in human bone marrow, clearly indicated that ALDH+CD34- cells are mainly committed towards erythropoiesis. To the best of our knowledge this finding is new and could be useful for basic studies about normal erythropoietic differentiation as well as for enabling the employment of ALDH as a red cell marker in polychromatic flow cytometry characterization of bone marrow from patients with aplastic anemia and myelodysplasia. PMID:18510759

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

NASA Technical Reports Server (NTRS)

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.

[Homeostasis and Disorder of Musculoskeletal System.Molecular mechanism of bone metabolism and future therapeutic strategies.

PubMed

Nakashima, Tomoki

Recent studies of mouse genetics and human gene mutations has greatly contributed to clarifying the molecular mechanism of bone metabolism. Bone is constantly renewed by the balanced action of osteoblastic bone formation and osteoclastic bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. Bone remodeling is stringently regulated by communication among bone component cells such as osteoclasts, osteoblasts, osteocytes and endothelial cells. An imbalance of this process is often linked to various bone diseases. Thus, the elucidation of the molecular mechanisms involved in bone remodeling is critical for a deeper understanding of the maintenance of healthy skeleton and bone disease.

Endocrine Regulation of Bone and Energy Metabolism in Hibernating Mammals

PubMed Central

Doherty, Alison H.; Florant, Gregory L.; Donahue, Seth W.

2014-01-01

Precise coordination among organs is required to maintain homeostasis throughout hibernation. This is particularly true in balancing bone remodeling processes (bone formation and resorption) in hibernators experiencing nutritional deprivation and extreme physical inactivity, two factors normally leading to pronounced bone loss in non-hibernating mammals. In recent years, important relationships between bone, fat, reproductive, and brain tissues have come to light. These systems share interconnected regulatory mechanisms of energy metabolism that potentially protect the skeleton during hibernation. This review focuses on the endocrine and neuroendocrine regulation of bone/fat/energy metabolism in hibernators. Hibernators appear to have unique mechanisms that protect musculoskeletal tissues while catabolizing their abundant stores of fat. Furthermore, the bone remodeling processes that normally cause disuse-induced bone loss in non-hibernators are compared to bone remodeling processes in hibernators, and possible adaptations of the bone signaling pathways that protect the skeleton during hibernation are discussed. Understanding the biological mechanisms that allow hibernators to survive the prolonged disuse and fasting associated with extreme environmental challenges will provide critical information regarding the limit of convergence in mammalian systems and of skeletal plasticity, and may contribute valuable insight into the etiology and treatment of human diseases. PMID:24556365

CELLS INVOLVED IN THE IMMUNE RESPONSE

PubMed Central

Abdou, Nabih I.; Richter, Maxwell

1969-01-01

Rabbits were made immunologically tolerant to either human serum albumin or bovine gamma globulin by the neonatal administration of antigen. At 10 wk of age, they were challenged with the tolerogenic antigen and found to be non-responsive. However, these tolerant rabbits could respond with humoral antibody formation directed toward the tolerogenic antigen if they were treated with normal, allogeneic bone marrow or bone marrow obtained from a rabbit made tolerant toward a different antigen. They were incapable of responding if they were given bone marrow obtained from a rabbit previously made tolerant to the tolerogenic antigen. Irradiated rabbits were unable to respond if treated with tolerant bone marrow, but could respond well if given normal bone marrow. Since it has previously been demonstrated that the antibody-forming cell, in an irradiated recipient of allogeneic bone marrow, is of recipient and not donor origin, the data presented strongly indicate that the unresponsive cell in the immunologically tolerant rabbit is the antigen-reactive cell. PMID:4183777

Potential anabolic effects of androgens on bone.

PubMed

Kearns, Ann E; Khosla, Sundeep

2004-04-01

Sex steroid hormones are essential to normal skeletal growth and maintenance throughout life in both men and women. The importance of estrogens to bone health in women becomes obvious at menopause when estrogen deficiency occurs and results in accelerated bone loss. After menopause, estrogen deficiency results in drastic changes in the androgen-estrogen ratio. Thus, the relative importance of androgens after menopause may increase. Androgens also appear to be important for bone health in pre-menopausal women. Evidence from human, animal, and laboratory studies is leading to a better understanding of the effects of androgens on bone in women.

A Novel Temporal Bone Simulation Model Using 3D Printing Techniques.

PubMed

Mowry, Sarah E; Jammal, Hachem; Myer, Charles; Solares, Clementino Arturo; Weinberger, Paul

2015-09-01

An inexpensive temporal bone model for use in a temporal bone dissection laboratory setting can be made using a commercially available, consumer-grade 3D printer. Several models for a simulated temporal bone have been described but use commercial-grade printers and materials to produce these models. The goal of this project was to produce a plastic simulated temporal bone on an inexpensive 3D printer that recreates the visual and haptic experience associated with drilling a human temporal bone. Images from a high-resolution CT of a normal temporal bone were converted into stereolithography files via commercially available software, with image conversion and print settings adjusted to achieve optimal print quality. The temporal bone model was printed using acrylonitrile butadiene styrene (ABS) plastic filament on a MakerBot 2x 3D printer. Simulated temporal bones were drilled by seven expert temporal bone surgeons, assessing the fidelity of the model as compared with a human cadaveric temporal bone. Using a four-point scale, the simulated bones were assessed for haptic experience and recreation of the temporal bone anatomy. The created model was felt to be an accurate representation of a human temporal bone. All raters felt strongly this would be a good training model for junior residents or to simulate difficult surgical anatomy. Material cost for each model was $1.92. A realistic, inexpensive, and easily reproducible temporal bone model can be created on a consumer-grade desktop 3D printer.

Human gingiva-derived mesenchymal stem cells are superior to bone marrow-derived mesenchymal stem cells for cell therapy in regenerative medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomar, Geetanjali B.; Srivastava, Rupesh K.; Gupta, Navita

2010-03-12

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation into multiple cell lineages. Presently, bone marrow is considered as a prime source of MSCs; however, there are some drawbacks and limitations in use of these MSCs for cell therapy. In this study, we demonstrate that human gingival tissue-derived MSCs have several advantages over bone marrow-derived MSCs. Gingival MSCs are easy to isolate, homogenous and proliferate faster than bone marrow MSCs without any growth factor. Importantly, gingival MSCs display stable morphology and do not loose MSC characteristic at higher passages. In addition, gingival MSCs maintain normal karyotype and telomerase activitymore » in long-term cultures, and are not tumorigenic. Thus, we reveal that human gingiva is a better source of MSCs than bone marrow, and large number of functionally competent clinical grade MSCs can be generated in short duration for cell therapy in regenerative medicine and tissue engineering.« less

Alteration of mineral crystallinity and collagen cross-linking of bones in osteopetrotic toothless (tl/tl) rats and their improvement after treatment with colony stimulating factor-1

NASA Technical Reports Server (NTRS)

Wojtowicz, A.; Dziedzic-Goclawska, A.; Kaminski, A.; Stachowicz, W.; Wojtowicz, K.; Marks, S. C. Jr; Yamauchi, M.

1997-01-01

A common feature of various types of mammalian osteopetroses is a marked increase in bone mass accompanied by spontaneous bone fractures. The toothless (tl/tl) rat osteopetrotic mutation is characterized by drastically reduced bone resorption due to a profound deficiency of osteoclasts and their precursors. An altered bone morphology has also been observed. The mutants cannot be cured by bone marrow transplantation, but skeletal defects are greatly reduced after treatment with colony stimulating factor 1 (CSF-1). The objectives of this study were to characterize mineral and collagen matrices in cancellous and compact bone isolated from long bones of 6-week-old normal littermates, tl/tl osteopetrotic mutants and mutants (tl/tl) treated with CSF-1. There were no differences in bone mineral content, but a significant decrease in the crystallinity of mineral evaluated by the method based on electron paramagnetic resonance spectrometry was observed in all bones of tl/tl mutants as compared to that of controls. Within the collagen matrix, slight decreases in the labile cross-links, but significant increases in the content of the stable cross-links, pyridinoline, and deoxypyridinoline, were observed in both cancellous and compact bone of osteopetrotic mutants. In tl/tl mutants treated with human recombinant CSF-1, the normalization of the crystallinity of bone mineral as well as collagen cross-links was found. Our results indicate that remodeling of bone matrix in tl/tl mutants is highly suppressed, but that after treatment with CSF-1, this activity recovers significantly. Taken together, these data provide further support for the hypothesis that CSF-1 is an essential factor for normal osteoclast differentiation and bone remodelling.

Characterization of microgravity effects on bone structure and strength using fractal analysis

NASA Technical Reports Server (NTRS)

Acharya, Raj S.; Shackelford, Linda

1995-01-01

The effect of micro-gravity on the musculoskeletal system has been well studied. Significant changes in bone and muscle have been shown after long term space flight. Similar changes have been demonstrated due to bed rest. Bone demineralization is particularly profound in weight bearing bones. Much of the current techniques to monitor bone condition use bone mass measurements. However, bone mass measurements are not reliable to distinguish Osteoporotic and Normal subjects. It has been shown that the overlap between normals and osteoporosis is found for all of the bone mass measurement technologies: single and dual photon absorptiometry, quantitative computed tomography and direct measurement of bone area/volume on biopsy as well as radiogrammetry. A similar discordance is noted in the fact that it has not been regularly possible to find the expected correlation between severity of osteoporosis and degree of bone loss. Structural parameters such as trabecular connectivity have been proposed as features for assessing bone conditions. In this report, we use fractal analysis to characterize bone structure. We show that the fractal dimension computed with MRI images and X-Ray images of the patella are the same. Preliminary experimental results show that the fractal dimension computed from MRI images of vertebrae of human subjects before bedrest is higher than during bedrest.

Selenium in bone health: roles in antioxidant protection and cell proliferation.

PubMed

Zeng, Huawei; Cao, Jay J; Combs, Gerald F

2013-01-10

Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health.

Selenium in Bone Health: Roles in Antioxidant Protection and Cell Proliferation

PubMed Central

Zeng, Huawei; Cao, Jay J.; Combs, Gerald F.

2013-01-01

Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health. PMID:23306191

Increased osteoblastic activity and expression of receptor activator of NF-kappaB ligand in nonuremic nephrotic syndrome.

PubMed

Freundlich, Michael; Alonzo, Evelyn; Bellorin-Font, Ezequiel; Weisinger, Jose R

2005-07-01

Patients with nephrotic syndrome (NS), even with normal GFR, often display altered mineral homeostasis and abnormal bone histology. However, the latter, mostly osteomalacia and increased bone resorption, cannot be readily explained by the prevalent concentrations of parathyroid hormone and vitamin D metabolites. The transmembrane receptor activator of NF-kappaB ligand (RANKL) of osteoblasts is essential for osteoclast formation and differentiation. Osteoblasts activity and the expression of RANKL were tested in cultures of normal human osteoblasts with sera obtained from patients with NS and normal GFR (129 +/- 26 ml/min per 1.73 m2) during relapse and remission of their NS. Osteoblasts that were cultured in vitro with sera during relapse displayed elevated concentrations of alkaline phosphatase (AP) and increased expression of RANKL. By contrast, during remission, AP concentrations were significantly lower (P < 0.05) and RANKL expression notably attenuated or absent. AP correlated with the proteinuria (r = 0.5, P < 0.05) and was not significantly affected by the therapeutic administration of corticosteroids. Whereas parathyroid hormone levels were normal (35 +/- 21 pg/ml), the serum markers of bone formation (osteocalcin and bone-specific alkaline phosphatase) were lower during relapse compared with remission. Thus, sera from patients with NS and normal GFR stimulate the activity of osteoblasts and upregulate their expression of RANKL. These alterations, more prominent during clinically active NS, are transient and reversible upon remission. These disturbances of bone biology may play an important pathogenic role in the abnormal bone histology observed in patients with NS even before a decline in GFR occurs.

Anisotropic analysis of trabecular architecture in human femur bone radiographs using quaternion wavelet transforms.

PubMed

Sangeetha, S; Sujatha, C M; Manamalli, D

2014-01-01

In this work, anisotropy of compressive and tensile strength regions of femur trabecular bone are analysed using quaternion wavelet transforms. The normal and abnormal femur trabecular bone radiographic images are considered for this study. The sub-anatomic regions, which include compressive and tensile regions, are delineated using pre-processing procedures. These delineated regions are subjected to quaternion wavelet transforms and statistical parameters are derived from the transformed images. These parameters are correlated with apparent porosity, which is derived from the strength regions. Further, anisotropy is also calculated from the transformed images and is analyzed. Results show that the anisotropy values derived from second and third phase components of quaternion wavelet transform are found to be distinct for normal and abnormal samples with high statistical significance for both compressive and tensile regions. These investigations demonstrate that architectural anisotropy derived from QWT analysis is able to differentiate normal and abnormal samples.

Quantitative in vivo assessment of bone microarchitecture in the human knee using HR-pQCT.

PubMed

Kroker, Andres; Zhu, Ying; Manske, Sarah L; Barber, Rhamona; Mohtadi, Nicholas; Boyd, Steven K

2017-04-01

High-resolution peripheral quantitative computed tomography (HR-pQCT) is a novel imaging modality capable of visualizing bone microarchitecture in vivo at human peripheral sites such as the distal radius and distal tibia. This research has extended the technology to provide a non-invasive assessment of bone microarchitecture at the human knee by establishing new hardware, imaging protocols and data analysis. A custom leg holder was developed to stabilize a human knee centrally within a second generation HR-pQCT field of view. Five participants with anterior cruciate ligament reconstructions had their knee joint imaged in a continuous scan of 6cm axially. The nominal isotropic voxel size was 60.7μm. Bone mineral density and microarchitecture were assessed within the weight-bearing regions of medial and lateral compartments of the knee at three depths from the weight-bearing articular bone surface, including both the cortical and trabecular bone regions. Scan duration was approximately 18min per knee and produced 5GB of projection data and 10GB of reconstructed image data (2304×2304 image matrix, 1008 slices). Motion during the scan was minimized by the leg holder and was similar in magnitude as a scan of the distal tibia. Bone mineral density and microarchitectural parameters were assessed for 16 volumes of interest in the tibiofemoral joint. This is a new non-invasive in vivo assessment tool for bone microarchitecture in the human knee that provides an opportunity to gain insight into normal, injured and surgically reconstructed human knee bone architecture in cross-sectional or longitudinal studies. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Survival and characteristics of murine leukaemic and normal stem cells after hyperthermia: a murine model for human bone marrow purging.

PubMed

Gidáli, J; Szamosvölgyi, S; Fehér, I; Kovács, P

1990-01-01

The effect of hyperthermia in vitro on the survival and leukaemogenic effectiveness of WEHI 3-B cells and on the survival and transplantation efficiency of bone marrow cells was compared in a murine model system. Normal murine clonogenic haemopoietic cells (day 9 CFU-S and CFU-GM) proved to be significantly less sensitive to 42.5 degrees C hyperthermia (Do values: 54.3 and 41.1 min, respectively) than leukaemic clonogenic cells (CFU-L) derived from suspension culture or from bone marrow of leukaemic mice (Do: 17.8 min). Exposure for 120 min to 42.5 degrees C reduced the surviving fraction of CFU-L to 0.002 and that of CFU-S to 0.2. If comparable graft sizes were transplanted from normal or heat exposed bone marrow, 60-day survival of supralethally irradiated mice was similar. Surviving WEHI 3-B cells were capable of inducing leukaemia in vivo. The two log difference in the surviving fraction of CFU-L and CFU-S after 120 min exposure to 42.5 degrees C suggests that hyperthermia ex vivo may be a suitable purging method for autologous bone marrow transplantation.

Noninvasive markers of bone metabolism in the rhesus monkey: normal effects of age and gender

NASA Technical Reports Server (NTRS)

Cahoon, S.; Boden, S. D.; Gould, K. G.; Vailas, A. C.

1996-01-01

Measurement of bone turnover in conditions such as osteoporosis has been limited by the need for invasive iliac bone biopsy to reliably determine parameters of bone metabolism. Recent advances in the area of serum and urinary markers of bone metabolism have raised the possibility for noninvasive measurements; however, little nonhuman primate data exist for these parameters. The purpose of this experiment was to define the normal range and variability of several of the newer noninvasive bone markers which are currently under investigation in humans. The primary intent was to determine age and gender variability, as well as provide some normative data for future experiments in nonhuman primates. Twenty-four rhesus macaques were divided into equal groups of male and female according to the following age groupings: 3 years, 5-10 years, 15-20 years, and > 25 years. Urine was collected three times daily for a four-day period and measured for several markers of bone turnoverm including pyridinoline (PYD), deoxypyrodinoline (DPD), hydroxyproline, and creatinine. Bone mineral density measurements of the lumbar spine were performed at the beginning and end of the study period. Serum was also obtained at the time of bone densitometry for measurement of osteocalcin levels by radioimmunoassay. There were no significant differences in bone mineral density, urine PYD, or urine DPD based on gender. Bone density was lowest in the youngest animals, peaked in the 15-20-year group, but again decreased in the oldest animals. The osteocalcin, PYD, and DPD levels followed an inversely related pattern to bone density. The most important result was the relative age insensitivity of the ratio of PYD:DPD in monkeys up to age 20 years. Since bone density changes take months or years to become measurable and iliac biopsies are invasive, the PYD/DPD marker ratio may have important implications for rapid noninvasive measurement of the effects of potential treatments for osteoporosis in the non-human primate model.

Abdominal Fat and Sarcopenia in Women Significantly Alter Osteoblasts Homeostasis In Vitro by a WNT/β-Catenin Dependent Mechanism

PubMed Central

Wannenes, Francesca; Papa, Vincenza; Greco, Emanuela A.; Fornari, Rachele; Marocco, Chiara; Di Luigi, Luigi; Donini, Lorenzo M.; Lenzi, Andrea

2014-01-01

Obesity and sarcopenia have been associated with mineral metabolism derangement and low bone mineral density (BMD). We investigated whether imbalance of serum factors in obese or obese sarcopenic patients could affect bone cell activity in vitro. To evaluate and characterize potential cellular and molecular changes of human osteoblasts, cells were exposed to sera of four groups of patients: (1) affected by obesity with normal BMD (O), (2) affected by obesity with low BMD (OO), (3) affected by obesity and sarcopenia (OS), and (4) affected by obesity, sarcopenia, and low BMD (OOS) as compared to subjects with normal body weight and normal BMD (CTL). Patients were previously investigated and characterized for body composition, biochemical and bone turnover markers. Then, sera of different groups of patients were used to incubate human osteoblasts and evaluate potential alterations in cell homeostasis. Exposure to OO, OS, and OOS sera significantly reduced alkaline phosphatase, osteopontin, and BMP4 expression compared to cells exposed to O and CTL, indicating a detrimental effect on osteoblast differentiation. Interestingly, sera of all groups of patients induced intracellular alteration in Wnt/β-catenin molecular pathway, as demonstrated by the significant alteration of specific target genes expression and by altered β-catenin cellular compartmentalization and GSK3β phosphorylation. In conclusion our results show for the first time that sera of obese subjects with low bone mineral density and sarcopenia significantly alter osteoblasts homeostasis in vitro, indicating potential detrimental effects of trunk fat on bone formation and skeletal homeostasis. PMID:24963291

Cellular Sites of Immunologic Unresponsiveness*

PubMed Central

Chiller, Jacques M.; Habicht, Gail S.; Weigle, William O.

1970-01-01

The reconstitution of the immune response of lethally irradiated mice to human γ-globulin is dependent on the synergistic action of bone marrow with thymus cells. Immunologic unresponsiveness appears to involve a functional defect at each of these cellular levels, inasmuch as neither bone marrow nor thymus cells from unresponsive donors are capable of demonstrating synergism in combination with their normal counterpart. PMID:4192271

Promising efficacy of Escherichia coli recombinant human bone morphogenetic protein-2 in collagen sponge for ectopic and orthotopic bone formation and comparison with mammalian cell recombinant human bone morphogenetic protein-2.

PubMed

Kim, In Sook; Lee, Eui Nam; Cho, Tae Hyung; Song, Yun Mi; Hwang, Soon Jung; Oh, Ji Hye; Park, Eun Kyung; Koo, Tai Young; Seo, Young-Kwon

2011-02-01

Nonglycosylated recombinant human bone morphogenetic protein (rhBMP)-2 prepared in Escherichia coli (E. coli rhBMP-2) has recently been considered as an alternative to mammalian cell rhBMP-2. However, its clinical use is still limited owing to lack of evidence for osteogenic activity comparable with that of mammalian cell rhBMP-2 via microcomputed tomography-based analysis. Therefore, this study aimed to evaluate the ability of E. coli rhBMP-2 in absorbable collagen sponge to form ectopic and orthotopic bone and to compare it to that of mammalian rhBMP-2. In vitro investigation was performed to study osteoblast differentiation of human mesenchymal stromal cells. Both types of rhBMP-2 enhanced proliferation, alkaline phosphatase activity, and matrix mineralization of human mesenchymal stromal cells at similar levels. Similar tendencies were observed in microcomputed tomography analysis, which determined bone volume, fractional bone volume, trabecular thickness, trabecular separation, bone mineral density, and other characteristics. Histology from an in vivo osteoinductivity test and from a rat calvarial defect model demonstrated a dose-dependent increase in local bone formation. The E. coli rhBMP-2 group (5 μg) not only induced complete regeneration of an 8-mm critical-sized defect at 4 weeks, but also led to new bone with the same bone mineral density as normal bone at 8 weeks, with the same efficiency as that of mammalian cell rhBMP-2 (5 μg). These uniformly favorable results provide evidence that the osteogenic activity of E. coli rhBMP-2 is not inferior to that of mammalian cell rhBMP-2 despite its low solubility and lack of gylcosylation. These results suggest that the application of E. coli rhBMP-2 in absorbable collagen sponge may be a promising equivalent to mammalian cell rhBMP-2 in bone tissue engineering.

Stationary Apparatus Would Apply Forces of Walking to Feet

NASA Technical Reports Server (NTRS)

Hauss, Jessica; Wood, John; Budinoff, Jason; Correia, Michael; Albrecht, Rudolf

2006-01-01

A proposed apparatus would apply controlled cyclic forces to both feet for the purpose of preventing the loss of bone density in a human subject whose bones are not subjected daily to the mechanical loads of normal activity in normal Earth gravitation. The apparatus was conceived for use by astronauts on long missions in outer space; it could also be used by bedridden patients on Earth, including patients too weak to generate the necessary forces by their own efforts. The apparatus (see figure) would be a modified version of a bicycle-like exercise machine, called the cycle ergometer with vibration isolation system (CEVIS), now aboard the International Space Station. Attached to each CEVIS pedal would be a computer-controlled stress/ vibration exciter connected to the heel portion of a special-purpose pedal. The user would wear custom shoes that would amount to standard bicycle shoes equipped with cleats for secure attachment of the balls of the feet to the special- purpose pedals. If possible, prior to use of the apparatus, the human subject would wear a portable network of recording accelerometers, while walking, jogging, and running. The information thus gathered would be fed to the computer, wherein it would be used to make the exciters apply forces and vibrations closely approximating the forces and vibrations experienced by that individual during normal exercise. It is anticipated that like the forces applied to bones during natural exercise, these artificial forces would stimulate the production of osteoblasts (bone-forming cells), as needed to prevent or retard loss of bone mass. In addition to helping to prevent deterioration of bones, the apparatus could be used in treating a person already suffering from osteoporosis. For this purpose, the magnitude of the applied forces could be reduced, if necessary, to a level at which weak hip and leg bones would still be stimulated to produce osteoblasts without exposing them to the full stresses of walking and thereby risking fracture.

Characterization of Human Bone Alkaline Phosphatase in Pichia Pastoris

NASA Technical Reports Server (NTRS)

Malone, Christine C.; Ciszak, Eva; Karr, Laurel J.

1999-01-01

A soluble form of human bone alkaline phosphatase has been expressed in a recombinant strain of the methylotrophic yeast Pichia pastoris. We constructed a plasmid containing cDNA encoding for human bone alkaline phosphatase, with the hydrophobic carboxyl terminal portion deleted. Alkaline phosphatase was secreted into the medium to a level of 32mg/L when cultured in shake flasks, and enzyme activity was 12U/mg, as measured by a spectrophotometric assay. By conversion to a fermentation system, a yield of 880mg/L has been achieved with an enzyme activity of 968U/mg. By gel electrophoresis analysis, it appears that greater than 50% of the total protein in the fermentation media is alkaline phosphatase. Although purification procedures are not yet completely optimized, they are expected to include filtration, ion exchange and affinity chromatography. Our presentation will focus on the purification and crystallization results up to the time of the conference. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

Steroid and xenobiotic receptor-mediated effects of bisphenol A on human osteoblasts.

PubMed

Miki, Yasuhiro; Hata, Shuko; Nagasaki, Shuji; Suzuki, Takashi; Ito, Kiyoshi; Kumamoto, Hiroyuki; Sasano, Hironobu

2016-06-15

Bisphenol A, one of the industrial chemicals used in plastics and in the coating of dishes and medical equipment, behaves as an endocrine disruptor in the human body. Bisphenol A can bind directly to several types of nuclear receptors, including steroid and xenobiotic receptor (SXR). SXR plays an important role in bone metabolism through the activation of osteoblasts in vitro, but SXR protein localization has not been reported in bone tissues. Additionally, it is not known whether bisphenol A acts on osteoblasts through SXR activation. Therefore, in this study, we first examined the immunolocalization of the SXR protein in human adult and fetal bone tissues. We then examined the effects of bisphenol A on human osteoblasts in vitro. SXR immunoreactivity was detected in osteoblasts, but not in osteoclasts, of both adult and fetal bone tissues. In fetal bone tissues, the mesenchymal cells or fetal connective tissue were also positive for SXR immunoreactivity. Expression of SXR target genes (tsukushi, matrilin-2, and CYP3A4) and SXR response element-luciferase activity were increased by bisphenol A treatment in normal osteoblasts transfected with SXR (hFOB/SXR) and in osteoblast-like cells (MG-63). Bisphenol A also stimulated cell proliferation and collagen accumulation in hFOB/SXR cells. These results suggest that, as in other tissues, SXR plays important roles in bone metabolism and fetal bone development and that bisphenol A may disturb bone homeostasis in both adult and fetus through SXR. Copyright © 2016 Elsevier Inc. All rights reserved.

Proteinase-activated receptor (PAR)-2 activation impacts bone resorptive properties of human osteoarthritic subchondral bone osteoblasts.

PubMed

Amiable, Nathalie; Tat, Steeve Kwan; Lajeunesse, Daniel; Duval, Nicolas; Pelletier, Jean-Pierre; Martel-Pelletier, Johanne; Boileau, Christelle

2009-06-01

In osteoarthritis (OA), the subchondral bone undergoes a remodelling process involving several factors synthesized by osteoblasts. In this study, we investigated the expression, production, modulation, and role of PAR-2 in human OA subchondral bone osteoblasts. PAR-2 expression and production were determined by real-time PCR and flow cytometry, respectively. PAR-2 modulation was investigated in OA subchondral bone osteoblasts treated with IL-1 beta (100 pg/ml), TNF-alpha (5 ng/ml), TGF-beta1 (10 ng/ml), PGE(2) (500 nM), IL-6 (10 ng/ml) and IL-17 (10 ng/ml). Membranous RANKL protein was assessed by flow cytometry, and OPG, MMP-1, MMP-9, MMP-13, IL-6 and intracellular signalling pathways by specific ELISAs. Bone resorptive activity was measured by using a co-culture model of human PBMC and OA subchondral bone osteoblasts. PAR-2 expression and production (p<0.05) were markedly increased when human OA subchondral bone osteoblasts were compared to normal. On OA osteoblasts, PAR-2 production was significantly increased by IL-1 beta, TNF-alpha and PGE(2). Activation of PAR-2 with a specific agonist, SLIGKV-NH(2), induced a significant up-regulation of MMP-1, MMP-9, IL-6, and membranous RANKL, but had no effect on MMP-13 or OPG production. Interestingly, bone resorptive activity was also significantly enhanced following PAR-2 activation. The PAR-2 effect was mediated by activation of the MAP kinases Erk1/2 and JNK. This study is the first to demonstrate that PAR-2 activation plays a role in OA subchondral bone resorption via an up-regulation of major bone remodelling factors. These results shed new light on the potential of PAR-2 as a therapeutic target in OA.

Biocompatibility evaluation of HDPE-UHMWPE reinforced β-TCP nanocomposites using highly purified human osteoblast cells.

PubMed

Shokrgozar, M A; Farokhi, M; Rajaei, F; Bagheri, M H A; Azari, Sh; Ghasemi, I; Mottaghitalab, F; Azadmanesh, K; Radfar, J

2010-12-15

Biocompatibility of β-TCP/HDPE-UHMWPE nanocomposite as a new bone substitute material was evaluated by using highly purified human osteoblast cells. Human osteoblast cells were isolated from bone tissue and characterized by immunofluorescence Staining before and after purification using magnetic bead system. Moreover, proliferation, alkaline phosphatase production, cell attachment, calcium deposition, gene expression, and morphology of osteoblast cells on β-TCP/HDPE-UHMWPE nanocomposites were evaluated. The results have shown that the human osteoblast cells were successfully purified and were suitable for subsequent cell culturing process. The high proliferation rate of osteoblast cells on β-TCP/HDPE-UHMWPE nanocomposite confirmed the great biocompatibility of the scaffold. Expression of bone-specific genes was taken place after the cells were incubated in composite extract solutions. Furthermore, osteoblast cells were able to mineralize the matrix next to composite samples. Scanning electron microscopy demonstrated that cells had normal morphology on the scaffold. Thus, these results indicated that the nanosized β-TCP/HDPE-UHMWPE blend composites could be potential scaffold, which is used in bone tissue engineering. Copyright © 2010 Wiley Periodicals, Inc.

Overexpression of Human Bone Alkaline Phosphatase in Pichia Pastoris

NASA Technical Reports Server (NTRS)

Karr, Laurel; Malone, Christine, C.; Rose, M. Franklin (Technical Monitor)

2000-01-01

The Pichiapastoris expression system was utilized to produce functionally active human bone alkaline phosphatase in gram quantities. Bone alkaline phosphatase is a key enzyme in bone formation and biomineralization, yet important questions about its structural chemistry and interactions with other cellular enzymes in mineralizing tissues remain unanswered. A soluble form of human bone alkaline phosphatase was constructed by deletion of the 25 amino acid hydrophobic C-terminal region of the encoding cDNA and inserted into the X-33 Pichiapastoris strain. An overexpression system was developed in shake flasks and converted to large-scale fermentation. Alkaline phosphatase was secreted into the medium to a level of 32mgAL when cultured in shake flasks. Enzyme activity was 12U/mg measured by a spectrophotometric assay. Fermentation yielded 880mgAL with enzymatic activity of 968U/mg. Gel electrophoresis analysis indicates that greater than 50% of the total protein in the fermentation is alkaline phosphatase. A purification scheme has been developed using ammonium sulfate precipitation followed by hydrophobic interaction chromatography. We are currently screening crystallization conditions of the purified recombinant protein for subsequent X-ray diffraction analyses. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

Biphasic positive effect of formononetin on metabolic activity of human normal and osteoarthritic subchondral osteoblasts.

PubMed

Huh, Jeong-Eun; Seo, Dong-Min; Baek, Yong-Hyeon; Choi, Do-Young; Park, Dong-Suk; Lee, Jae-Dong

2010-04-01

Osteoarthritis is a multifactorial disease characterized by loss of articular cartilage and subchondral plate thickening. Therefore, biochemical analysis of the underlying bone tissue has provided important information for treatment of osteoarthritis. In this study, we determined the potential role of formononetin, a phytoestrogen isolated from Astragalus membranaceus to alter the expression of metabolic markers and cytokine production of human normal osteoblasts (Obs) and osteoarthritis subchondral osteoblasts (OA Obs). Human OA Obs and normal Obs were cultured for 3days, 7days or 14days in the present medium only or were treated with various doses of formononetin. Cells were analyzed for viability by WST-8 assay, alkaline phosphatase (ALP) activity, osteogenic markers (osteocalcin (OCN) and type I collagen (Col I)) and cytokines (interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), bone morphogenic protein-2 (BMP-2)). The level of IL-6, VEGF, BMP-2, OCN and Col I was increased in OA Obs compared with normal Obs. Formononetin dose-dependently decreased ALP, IL-6, VEGF, BMP-2, OCN and Col I in OA Obs, while markedly increased ALP, VEGF, BMP-2, OCN and Col I in normal Obs. Interestingly, formononetin markedly increased the expression of VEGF and BMP-2 for 3days of culture and significantly increased OCN and Col I at 14days in human normal Obs. The remodeling effect of formononetin on osteogenic markers and cytokines of inflammatory mediators was more striking in OA Obs as well. Taken together, these results could suggest that formononetin has biphasic positive effects on normal Obs and OA Obs by modifying their biological synthetic capacities. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

Denosumab for the management of bone disease in patients with solid tumors.

PubMed

Body, Jean-Jacques

2012-03-01

Many patients with advanced cancer develop bone metastases, which reduces their quality of life. Bone metastases are associated with an increased risk of skeletal-related events, which can lead to increased morbidity and mortality. In patients with bone metastases, tumor cells disrupt the normal process of bone remodeling, leading to increased bone destruction. Denosumab is a fully human monoclonal antibody against receptor activator of NF-κB ligand (RANKL), a key regulatory factor in bone remodeling. By binding to RANKL, denosumab disrupts the cycle of bone destruction. In clinical studies in patients with prostate or breast cancer and bone metastases, denosumab was superior to the current standard of care, zoledronic acid, for delaying skeletal-related events, while in patients with other solid tumors or multiple myeloma, denosumab was noninferior to zoledronic acid. This article examines the pharmacokinetics, efficacy, and safety and tolerability of denosumab for the management of bone events in patients with cancer.

Wavelet analysis in two-dimensional tomography

NASA Astrophysics Data System (ADS)

Burkovets, Dimitry N.

2002-02-01

The diagnostic possibilities of wavelet-analysis of coherent images of connective tissue in its pathological changes diagnostics. The effectiveness of polarization selection in obtaining wavelet-coefficients' images is also shown. The wavelet structures, characterizing the process of skin psoriasis, bone-tissue osteoporosis have been analyzed. The histological sections of physiological normal and pathologically changed samples of connective tissue of human skin and spongy bone tissue have been analyzed.

Rictor is required for optimal bone accrual in response to anti-sclerostin therapy in the mouse.

PubMed

Sun, Weiwei; Shi, Yu; Lee, Wen-Chih; Lee, Seung-Yon; Long, Fanxin

2016-04-01

Wnt signaling has emerged as a major target pathway for the development of novel bone anabolic therapies. Neutralizing antibodies against the secreted Wnt antagonist sclerostin (Scl-Ab) increase bone mass in both animal models and humans. Because we have previously shown that Rictor-dependent mTORC2 activity contributes to Wnt signaling, we test here whether Rictor is required for Scl-Ab to promote bone anabolism. Mice with Rictor deleted in the early embryonic limb mesenchyme (Prx1-Cre;Rictor(f/f), hereafter RiCKO) were subjected to Scl-Ab treatment for 5weeks starting at 4months of age. In vivo micro-computed tomography (μCT) analyses before the treatment showed that the RiCKO mice displayed normal trabecular, but less cortical bone mass than the littermate controls. After 5weeks of treatment, Scl-Ab dose-dependently increased trabecular and cortical bone mass in both control and RiCKO mice, but the increase was significantly blunted in the latter. Dynamic histomorphometry revealed that the RiCKO mice formed less bone than the control in response to Scl-Ab. In addition, the RiCKO mice possessed fewer osteoclasts than normal under the basal condition and exhibited lesser suppression in osteoclast number by Scl-Ab. Consistent with the fewer osteoclasts in vivo, bone marrow stromal cells (BMSC) from the RiCKO mice expressed less Rankl but normal levels of Opg or M-CSF, and were less effective than the control cells in supporting osteoclastogenesis in vitro. The reliance of Rankl on Rictor appeared to be independent of Wnt-β-catenin or Wnt-mTORC2 signaling as Wnt3a had no effect on Rankl expression by BMSC from either control or RICKO mice. Overall, Rictor in the limb mesenchymal lineage is required for the normal response to the anti-sclerostin therapy in both bone formation and resorption. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of calcium phosphate/chitosan composite on bone healing in rats: calcium phosphate induces osteon formation.

PubMed

Fernández, Tulio; Olave, Gilberto; Valencia, Carlos H; Arce, Sandra; Quinn, Julian M W; Thouas, George A; Chen, Qi-Zhi

2014-07-01

Vascularization of an artificial graft represents one of the most significant challenges facing the field of bone tissue engineering. Over the past decade, strategies to vascularize artificial scaffolds have been intensively evaluated using osteoinductive calcium phosphate (CaP) biomaterials in animal models. In this work, we observed that CaP-based biomaterials implanted into rat calvarial defects showed remarkably accelerated formation and mineralization of new woven bone in defects in the initial stages, at a rate of ∼60 μm/day (0.8 mg/day), which was considerably higher than normal bone growth rates (several μm/day, 0.1 mg/day) in implant-free controls of the same age. Surprisingly, we also observed histological evidence of primary osteon formation, indicated by blood vessels in early-region fibrous tissue, which was encapsulated by lamellar osteocyte structures. These were later fully replaced by compact bone, indicating complete regeneration of calvarial bone. Thus, the CaP biomaterial used here is not only osteoinductive, but vasculogenic, and it may have contributed to the bone regeneration, despite an absence of osteons in normal rat calvaria. Further investigation will involve how this strategy can regulate formation of vascularized cortical bone such as by control of degradation rate, and use of models of long, dense bones, to more closely approximate repair of human cortical bone.

Genomic deletion of a long-range bone enhancer misregulatessclerostin in Van Buchem disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loots, Gabriela G.; Kneissel, Michaela; Keller, Hansjoerg

2005-04-15

Mutations in distant regulatory elements can negatively impact human development and health, yet due to the difficulty of detecting these critical sequences we predominantly focus on coding sequences for diagnostic purposes. We have undertaken a comparative sequence-based approach to characterize a large noncoding region deleted in patients affected by Van Buchem disease (VB), a severe sclerosing bone dysplasia. Using BAC recombination and transgenesis we characterized the expression of human sclerostin (sost) from normal (hSOSTwt) or Van Buchem(hSOSTvb D) alleles. Only the hSOSTwt allele faithfully expressed high levels of human sost in the adult bone and impacted bone metabolism, consistent withmore » the model that the VB noncoding deletion removes a sost specific regulatory element. By exploiting cross-species sequence comparisons with in vitro and in vivo enhancer assays we were able to identify a candidate enhancer element that drives human sost expression in osteoblast-like cell lines in vitro and in the skeletal anlage of the E14.5 mouse embryo, and discovered a novel function for sclerostin during limb development. Our approach represents a framework for characterizing distant regulatory elements associated with abnormal human phenotypes.« less

The effects of twelve weeks of bed rest on bone histology, biochemical markers of bone turnover, and calcium homeostasis in eleven normal subjects

NASA Technical Reports Server (NTRS)

Zerwekh, J. E.; Ruml, L. A.; Gottschalk, F.; Pak, C. Y.; Blomqvist, C. G. (Principal Investigator)

1998-01-01

This study was undertaken to examine the effects of 12 weeks of skeletal unloading on parameters of calcium homeostasis, calcitropic hormones, bone histology, and biochemical markers of bone turnover in 11 normal subjects (9 men, 2 women; 34 +/- 11 years of age). Following an ambulatory control evaluation, all subjects underwent 12 weeks of bed rest. An additional metabolic evaluation was performed after 12 days of reambulation. Bone mineral density declined at the spine (-2.9%, p = 0.092) and at the hip (-3.8%, p = 0.002 for the trochanter). Bed rest prompted a rapid, sustained, significant increase in urinary calcium and phosphorus as well as a significant increase in serum calcium. Urinary calcium increased from a pre-bed rest value of 5.3 mmol/day to values as high as 73 mmol/day during bed rest. Immunoreactive parathyroid hormone and serum 1,25-dihydroxyvitamin D declined significantly during bed rest, although the mean values remained within normal limits. Significant changes in bone histology included a suppression of osteoblastic surface for cancellous bone (3.1 +/- 1.3% to 1.9 +/- 1.5%, p = 0.0142) and increased bone resorption for both cancellous and cortical bone. Cortical eroded surface increased from 3.5 +/- 1.1% to 7.3 +/- 4.0% (p = 0.018) as did active osteoclastic surface (0.2 +/- 0.3% to 0.7 +/- 0.7%, p = 0.021). Cancellous eroded surface increased from 2.1 +/- 1.1% to 4.7 +/- 2.2% (p = 0.002), while mean active osteoclastic surface doubled (0.2 +/- 0.2% to 0.4 +/- 0.3%, p = 0.020). Serum biochemical markers of bone formation (osteocalcin, bone-specific alkaline phosphatase, and type I procollagen extension peptide) did not change significantly during bed rest. Urinary biochemical markers of bone resorption (hydroxyproline, deoxypyridinoline, and N-telopeptide of type I collagen) as well as a serum marker of bone resorption (type I collagen carboxytelopeptide) all demonstrated significant increases during bed rest which declined toward normal during reambulation. Thus, under the conditions of this study, the human skeleton appears to respond to unloading by a rapid and sustained increase in bone resorption and a more subtle decrease in bone formation.

Bare Bones of Bioactive Glass

NASA Technical Reports Server (NTRS)

2000-01-01

Paul Ducheyne, a principal investigator in the microgravity materials science program and head of the University of Pernsylvania's Center for Bioactive Materials and Tissue Engineering, is leading the trio as they use simulated microgravity to determine the optimal characteristics of tiny glass particles for growing bone tissue. The result could make possible a much broader range of synthetic bone-grafting applications. Even in normal gravity, bioactive glass particles enhance bone growth in laboratory tests with flat tissue cultures. Ducheyne and his team believe that using the bioactive microcarriers in a rotating bioreactor in microgravity will produce improved, three-dimensional tissue cultures. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: NASA and University of Pennsylvania Center for Bioactive Materials and Tissue Engineering.

Treatment-naïve Gaucher disease patients achieve therapeutic goals and normalization with velaglucerase alfa by 4years in phase 3 trials.

PubMed

Zimran, Ari; Elstein, Deborah; Gonzalez, Derlis E; Lukina, Elena A; Qin, Yulin; Dinh, Quinn; Turkia, Hadhami Ben

2018-02-01

Gaucher disease is an inherited metabolic disease characterized by β-glucocerebrosidase deficiency and commonly treated with enzyme replacement therapy (ERT). The efficacy of ERT with velaglucerase alfa was assessed based on the achievement of published therapeutic goals and the normalization of disease parameters in 39 treatment-naïve patients with type 1 Gaucher disease, 6 to 62years of age, enrolled in phase 3 clinical trials. After 4years of ERT, therapeutic goals for thrombocytopenia and splenomegaly had been achieved in 100% of patients; goals for anemia and hepatomegaly had been achieved in 95% and 94% of patients, respectively. Consistent with the goal for bone mineral density, lumbar spine bone density improved in 87% of patients ≥18years of age. At year 4, compared with clinical ranges for healthy individuals, 86% of patients with a low baseline hemoglobin concentration had normalized, 60% with a low baseline platelet count had normalized, 67% with baseline splenomegaly had normalized, 58% with hepatomegaly had normalized, and lumbar spine bone density had normalized in 53% of adults. The decade-old therapeutic goals do not reflect the potential for normalization of clinical parameters in ERT-treated patients. Goals consistent with normalization or near-normalization should be considered. ClinicalTrials.gov identifiers: NCT00430625, NCT00553631, NCT00635427. Copyright © 2016 Shire Human Genetic Therapies, Inc. Published by Elsevier Inc. All rights reserved.

Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

PubMed

Prisby, Rhonda D

2014-07-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p<0.05) in the old vs. young rats. Calcified and ossified vessel volumes per tissue volume and calcified vessel volume per patent vessel volume were augmented (p<0.05) 262%, 375% and 263%, respectively, in the old vs. young rats. Ossified and patent vessel number was higher (171%) and lower (40%), respectively, in the old vs. young rats. Finally, adipocyte volume per patent vessel volume was higher (86%) with age. This study is the first to report ossification of bone marrow blood vessels in rats and humans. Ossification presumably results in "microvascular dead space" in regard to loss of patency and vasomotor function as opposed to necrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. Copyright © 2014 Elsevier Inc. All rights reserved.

Quantification of Cyclic Ground Reaction Force Histories During Daily Activity in Humans

NASA Technical Reports Server (NTRS)

Breit, G. A.; Whalen, R. T.; Wade, Charles E. (Technical Monitor)

1994-01-01

Theoretical models and experimental studies of bone remodeling suggest that bone density and structure are influenced by local cyclic skeletal tissue stress and strain histories. Estimation of long-term loading histories in humans is usually achieved by assessment of physical activity level by questionnaires, logbooks, and pedometers, since the majority of lower limb cyclic loading occurs during walking and running. These methods provide some indication of the mechanical loading history, but fail to consider the true magnitude of the lower limb skeletal forces generated by various daily activities. These techniques cannot account for individual gait characteristics, gait speed, and unpredictable high loading events that may influence bone mass significantly. We have developed portable instrumentation to measure and record the vertical component of the ground reaction force (GRFz) during normal daily activity. This equipment allows long-term quantitative monitoring of musculoskeletal loads, which in conjunction with bone mineral density assessments, promises to elucidate the relationship between skeletal stresses and bone remodeling.

Elemental and structural studies at the bone-cartilage interface

NASA Astrophysics Data System (ADS)

Bradley, D. A.; Kaabar, W.; Gundogdu, O.

2012-02-01

The techniques μProton-Induced X-and γ-ray Emission, μ-PIXE and μ-PIGE, were used to investigate trace and essential element distributions in sections of normal and osteoarthritic (OA) human femoral head. μ-PIGE yielded 2-D mappings of Na and F while Ca, Z, P and S were mapped by μ-PIXE. The concentration of chondroitin sulphate supporting functionality in healthy cartilage is significantly reduced in OA samples. Localised Zn points to osteoblastic/osteoclastic activity at the bone-cartilage interface. Small-angle X-ray scattering applied to decalcified OA-affected tissue showed spatial alterations of collagen fibres of decreased axial periodicity compared to normal collagen type I.

Biomechanical measurements of stopping and stripping torques during screw insertion in five types of human and artificial humeri.

PubMed

Aziz, Mina Sr; Tsuji, Matthew Rs; Nicayenzi, Bruce; Crookshank, Meghan C; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2014-05-01

During orthopedic surgery, screws are inserted by "subjective feel" in humeri for fracture fixation, that is, stopping torque, while trying to prevent accidental over-tightening that causes screw-bone interface failure, that is, stripping torque. However, no studies exist on stopping torque, stripping torque, or stopping/stripping torque ratio in human or artificial humeri. This study evaluated five types of humeri, namely, human fresh-frozen (n = 19), human embalmed (n = 18), human dried (n = 15), artificial "normal" (n = 13), and artificial "osteoporotic" (n = 13). An orthopedic surgeon used a torque screwdriver to insert 3.5-mm-diameter cortical screws into humeral shafts and 6.5-mm-diameter cancellous screws into humeral heads by "subjective feel" to obtain stopping and stripping torques. The five outcome measures were raw and normalized stopping torque, raw and normalized stripping torque, and stopping/stripping torque ratio. Normalization was done as raw torque/screw-bone interface area. For "gold standard" fresh-frozen humeri, cortical screw tests yielded averages of 1312 N mm (raw stopping torque), 30.4 N/mm (normalized stopping torque), 1721 N mm (raw stripping torque), 39.0 N/mm (normalized stripping torque), and 82% (stopping/stripping torque ratio). Similarly, fresh-frozen humeri gave cancellous screw average results of 307 N mm (raw stopping torque), 0.9 N/mm (normalized stopping torque), 392 N mm (raw stripping torque), 1.2 N/mm (normalized stripping torque), and 79% (stopping/stripping torque ratio). Of the five cortical screw parameters for fresh-frozen humeri versus other groups, statistical equivalence (p ≥ 0.05) occurred in four cases (embalmed), three cases (dried), four cases (artificial "normal"), and four cases (artificial "osteoporotic"). Of the five cancellous screw parameters for fresh-frozen humeri versus other groups, statistical equivalence (p ≥ 0.05) occurred in five cases (embalmed), one case (dried), one case (artificial "normal"), and zero cases (artificial "osteoporotic"). Stopping/stripping torque ratios were relatively constant for all groups at 77%-88% (cortical screws) and 79%-92% (cancellous screws). © IMechE 2014.

Inflammatory bowel disease causes reversible suppression of osteoblast and chondrocyte function in mice.

PubMed

Harris, Laura; Senagore, Patricia; Young, Vincent B; McCabe, Laura R

2009-05-01

Decreased bone density and stature can occur in pediatric patients with inflammatory bowel disease (IBD). Little is known about how IBD broadly impacts the skeleton. To evaluate the influence of an acute episode of IBD on growing bone, 4-wk-old mice were administered 5% dextran sodium sulfate (DSS) for 5 days to induce colitis and their recovery was monitored. During active disease and early recovery, trabecular bone mineral density, bone volume, and thickness were decreased. Cortical bone thickness, outer perimeter, and density were also decreased, whereas inner perimeter and marrow area were increased. These changes appear to maintain bone strength since measures of moments of inertia were similar between DSS-treated and control mice. Histological (static and dynamic), serum, and RNA analyses indicate that a decrease in osteoblast maturation and function account for changes in bone density. Unlike some conditions of bone loss, marrow adiposity did not increase. Similar to reports in humans, bone length decreased and correlated with decreases in growth plate thickness and chondrocyte marker expression. During disease recovery, mice experienced a growth spurt that led to their achieving final body weights and bone length, density, and gene expression similar to healthy controls. Increased TNF-alpha and decreased IGF-I serum levels were observed with active disease and returned to normal with recovery. Changes in serum TNF-alpha (increased) and IGF-I (decreased) paralleled changes in bone parameters and returned to normal values with recovery, suggesting a potential role in the skeletal response.

Microgravity

NASA Image and Video Library

2000-12-15

Paul Ducheyne, a principal investigator in the microgravity materials science program and head of the University of Pernsylvania's Center for Bioactive Materials and Tissue Engineering, is leading the trio as they use simulated microgravity to determine the optimal characteristics of tiny glass particles for growing bone tissue. The result could make possible a much broader range of synthetic bone-grafting applications. Even in normal gravity, bioactive glass particles enhance bone growth in laboratory tests with flat tissue cultures. Ducheyne and his team believe that using the bioactive microcarriers in a rotating bioreactor in microgravity will produce improved, three-dimensional tissue cultures. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: NASA and University of Pennsylvania Center for Bioactive Materials and Tissue Engineering.

Anorexia Nervosa and its Associated Endocrinopathy in Young People

PubMed Central

Misra, Madhusmita; Klibanski, Anne

2016-01-01

Anorexia nervosa (AN) is a condition of severe undernutrition associated with adaptive changes in many endocrine axes. These changes include hypogonadotropic hypogonadism, acquired growth hormone resistance with low insulin like growth factor-1 (IGF-1) levels, hypercortisolemia, altered secretion of adipokines and appetite regulating hormones, and low bone mineral density (BMD). Bone health is impaired subsequent to low BMI, decreased lean mass, and the endocrine changes described above. In addition to low areal BMD, AN is characterized by a decrease in volumetric BMD, changes in bone geometry, and reductions in strength estimates, leading to an increased risk for fracture. Weight restoration is essential for restoration of normal endocrine function; however, hypercortisolemia, high PYY levels, and ghrelin dynamics may not completely normalize. In some patients, hypogonadotropic hypogonadism persists despite weight restoration. Weight gain and menstrual recovery are critical for improving bone health in AN, however, residual deficits may persist. Physiologic estrogen replacement using transdermal, but not oral, estrogen increases bone accrual in adolescents with AN, while bisphosphonates improve BMD in adults. Recombinant human IGF-1 and teriparatide have been used in a few studies as bone anabolic therapies. More data are necessary to determine the optimal therapeutic strategies for low BMD in AN. PMID:26863308

Normal Collagen and Bone Production by Gene-targeted Human Osteogenesis Imperfecta iPSCs

PubMed Central

Deyle, David R; Khan, Iram F; Ren, Gaoying; Wang, Pei-Rong; Kho, Jordan; Schwarze, Ulrike; Russell, David W

2012-01-01

Osteogenesis imperfecta (OI) is caused by dominant mutations in the type I collagen genes. In principle, the skeletal abnormalities of OI could be treated by transplantation of patient-specific, bone-forming cells that no longer express the mutant gene. Here, we develop this approach by isolating mesenchymal cells from OI patients, inactivating their mutant collagen genes by adeno-associated virus (AAV)-mediated gene targeting, and deriving induced pluripotent stem cells (iPSCs) that were expanded and differentiated into mesenchymal stem cells (iMSCs). Gene-targeted iMSCs produced normal collagen and formed bone in vivo, but were less senescent and proliferated more than bone-derived MSCs. To generate iPSCs that would be more appropriate for clinical use, the reprogramming and selectable marker transgenes were removed by Cre recombinase. These results demonstrate that the combination of gene targeting and iPSC derivation can be used to produce potentially therapeutic cells from patients with genetic disease. PMID:22031238

[Study on shape and structure of calcified cartilage zone in normal human knee joint].

PubMed

Wang, Fuyou; Yang, Liu; Duan, Xiaojun; Tan, Hongbo; Dai, Gang

2008-05-01

To explore the shape and structure of calcified cartilage zone and its interface between the non-calcified articular cartilage and subchondral bone plate. The normal human condyles of femur (n=20) were obtained from the tissue bank donated by the residents, 10 males and 10 females, aged 17-45 years. The longitudinal and transverse paraffin sections were prepared by the routine method. The shape and structure of calcified cartilage zone were observed with the Safranin O/fast green and von kossa stain method. The interface conjunction among zones of cartilage was researched by SEM and the 3D structural model was established by serial sections and modeling technique. Articular bone-cartilage safranin O/fast green staining showed that cartilage was stained red and subchondral bone was stained blue. The calcified cartilage zone was located between the tidemark and cement line. Von kossa staining showed that calcified cartilage zone was stained black and sharpness of structure border. Upper interface gomphosised tightly with the non-calcified cartilage by the wave shaped tidemark and lower interface anchored tightly with the subchondral bone by the uneven comb shaped cement line. The non-calcified cartilage zone was interlocked tightly in the manner of "ravine-engomphosis" by the calcified cartilage zone as observed under SEM, and the subchondral bone was anchored tightly in the manner of"comb-anchor" by the in the calcified cartilage zone 3D reconstruction model. The calcified cartilage zone is an important structure in the articular cartilage. The articular cartilage is fixed firmly into subchondral bone plate by the distinctive conjunct interfaces of calcified cartilage zone.

Yellow-bellied Marmots (Marmota flaviventris) preserve bone strength and microstructure during hibernation

PubMed Central

Wojda, Samantha J.; McGee-Lawrence, Meghan E.; Gridley, Richard A.; Auger, Janene; Black, Hal L.; Donahue, Seth W.

2012-01-01

Reduced skeletal loading typically results in decreased bone strength and increased fracture risk for humans and many other animals. Previous studies have shown bears are able to prevent bone loss during the disuse that occurs during hibernation. Studies with smaller hibernators, which arouse intermittently during hibernation, show that they may lose bone at the microstructural level. These small hibernators, like bats and squirrels, do not utilize intracortical remodeling. However, slightly larger mammals like marmots do. In this study we examined the effects of hibernation on bone structural, mineral, and mechanical properties in yellow-bellied marmots (Marmota flaviventris). This was done by comparing cortical bone properties in femurs and trabecular bone properties in tibias from marmots killed before hibernation (fall) and after hibernation (spring). Age data were not available for this study; however, based on femur length the post-hibernation marmots were larger than the pre-hibernation marmots. Thus, cross-sectional properties were normalized by allometric functions of bone length for comparisons between pre- and post-hibernation. Cortical thickness and normalized cortical area were higher in post-hibernation samples; no other normalized cross-sectional properties were different. No cortical bone microstructural loss was evident in osteocyte lacunar measurements, intracortical porosity, or intracortical remodeling cavity density. Osteocyte lacunar area, porosity, and density were surprisingly lower in post-hibernation samples. Trabecular bone volume fraction was not different between pre- and post-hibernation. Measures of both trabecular and cortical bone mineral content were higher in post-hibernation samples. Three-point bending failure load, failure energy, elastic energy, ultimate stress, and yield stress were all higher in post-hibernation samples. These results support the idea that, like bears, marmots are able to prevent disuse osteoporosis during hibernation, thus preventing increased fracture risk and promoting survival of the extreme environmental conditions that occur in hibernation. PMID:22037004

Yellow-bellied marmots (Marmota flaviventris) preserve bone strength and microstructure during hibernation.

PubMed

Wojda, Samantha J; McGee-Lawrence, Meghan E; Gridley, Richard A; Auger, Janene; Black, Hal L; Donahue, Seth W

2012-01-01

Reduced skeletal loading typically results in decreased bone strength and increased fracture risk for humans and many other animals. Previous studies have shown bears are able to prevent bone loss during the disuse that occurs during hibernation. Studies with smaller hibernators, which arouse intermittently during hibernation, show that they may lose bone at the microstructural level. These small hibernators, like bats and squirrels, do not utilize intracortical remodeling. However, slightly larger mammals like marmots do. In this study we examined the effects of hibernation on bone structural, mineral, and mechanical properties in yellow-bellied marmots (Marmota flaviventris). This was done by comparing cortical bone properties in femurs and trabecular bone properties in tibias from marmots killed before hibernation (fall) and after hibernation (spring). Age data were not available for this study; however, based on femur length the post-hibernation marmots were larger than the pre-hibernation marmots. Thus, cross-sectional properties were normalized by allometric functions of bone length for comparisons between pre- and post-hibernation. Cortical thickness and normalized cortical area were higher in post-hibernation samples; no other normalized cross-sectional properties were different. No cortical bone microstructural loss was evident in osteocyte lacunar measurements, intracortical porosity, or intracortical remodeling cavity density. Osteocyte lacunar area, porosity, and density were surprisingly lower in post-hibernation samples. Trabecular bone volume fraction was not different between pre- and post-hibernation. Measures of both trabecular and cortical bone mineral content were higher in post-hibernation samples. Three-point bending failure load, failure energy, elastic energy, ultimate stress, and yield stress were all higher in post-hibernation samples. These results support the idea that, like bears, marmots are able to prevent disuse osteoporosis during hibernation, thus preventing increased fracture risk and promoting survival of the extreme environmental conditions that occur in hibernation. Copyright © 2011 Elsevier Inc. All rights reserved.

CALCIUM-47 IN THE STUDY OF BONE PHYSIOLOGY AND PATHOLOGY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guerin, R.A.

1962-06-01

The use of Ca/sup 45/, Ca/sup 47/, Ga/sup 67/, and Sr/sup 85/ in the study of Ca metabolism of bone in human subjects is discussed. Ca/sup 47/ is considered to be most suitable because of its short half-life ( approximates 5 days) and high specific activity (10 mc/mg for Ca/sup 47/ Cl/sub 2/). Studies were conducted in 28 patients injected intravenously with Ca/sup 47/; uptake in various bones was followed by external scintillometry for periods up to 11 days later. In healthy subjects the distribution of activity was symmetrical, with highest uptake in sternum and manubrium and lower uptake inmore » cranium (particularly the occipital region), clavicle, and iliac crest. Epiphyses of the long bones showed less avidity for Ca/sup 47/, that in tibia being highest. Sternum fixed 2 to 21/2 more Ca/sup 47/ than the upper tibial epiphysis. This indicates that in the normal adult more Ca is taken up by spongy than compact bone. The Ca/sup 47/ content of bone increased rapidly, reaching a plateau by the 5th or 6th day in most bones and by the 10th day in some, such as clavicle. Studies in pathologic cases showed the very high, but transient, uptake by callus in fractures and and uptake in Paget's disease of bone that was 3 times normal. Higher than normal uptake was also noted in bone lesions in lymphogranulomatosis, where osteogenesis compensating for increased bone destruction could be detected. Pathologic states could also be detected by following the disappearance of Ca/sup 47/ from plasma, it being delayed by hypercalcemia associated with multiple cancer metastases in bone or accelerated by hypocalcemia, such as in Paget's disease. The rate of urinary excretion of radioactivity was also of diagnostic value. (H.H.D.)« less

Normal and leukaemic human haemopoietic cells in diffusion chamber. A morphological and functional CFU-C study.

PubMed

Laurent, M; Clémancey-Marcille, G; Hollard, D

1980-03-01

Leukaemic human bone marrow and peripheral blood cells were cultured for 25 d in diffusion chambers implanted into cyclophosphamide treated mice. Normal bone marrow cells were cultured simultaneously. These cells were studied both morphologically and functionally (CFU-C). The leukaemic cells behaved heterogeneously, 2 groups being distinguishable in accordance with their initial in vitro growth pattern (1: no growth or microcluster growth. 2: macrocluster growth). Group I showed progressive cellular death with a diminution of granulocytic progenitors and the appearance of a predominantly macrophagic population. This behaviour resembled that of the control group. The initial microcluster growth pattern remained identical throughout the entire culture period. Group 2, after considerable cellular death up to d 5, showed an explosive proliferation of the granulocytic progenitors and incomplete differentiation (up to myelocyte). The initial macrocluster growth pattern remained identical.

Homogeneous immunoglobulins in sera of Rhesus monkeys after lethal irradiation and bone marrow transplantation

PubMed Central

Rádl, J.; van den Berg, P.; Voormolen, M.; Hendriks, W. D. H.; Schaefer, U. W.

1974-01-01

The immunoglobulin pattern in the sera of lethally irradiated and bone marrow transplanted Rhesus monkeys was studied during the reconstitution of their immune system. All of the irradiated monkeys which survived longer than 30 days, and in which reconstitution of their immune system took place, also developed homogeneous immunoglobulins (HI) in their sera. These homogeneous, sometimes multiple, immunoglobulins were transient. However, they persisted frequently in the sera for several months. In two monkeys which were additionally immunized with a complex antigen (normal human serum), clear-cut M-components appeared in the serum about 10 days later. These HI of IgG class did not precipitate the antigen in immunodiffusion techniques; however, when passing the serum through an immunoadsorbent prepared from normal human serum, only the HI were specifically retained on the column and afterwards isolated by elution. ImagesFIG. 1FIG. 2 PMID:4143277

Expression of myeloid differentiation antigens on normal and malignant myeloid cells.

PubMed Central

Griffin, J D; Ritz, J; Nadler, L M; Schlossman, S F

1981-01-01

A series of monoclonal antibodies have been characterized that define four surface antigens (MY3, MY4, MY7, and MY8) of human myeloid cells. They were derived from a fusion of the NS-1 plasmacytoma cell line with splenocytes from a mouse immunized with human acute myelomonocytic leukemia cells. MY3 and MY4 are expressed by normal monocytes and by greater than 90% of patients with acute monocytic leukemia or acute myelomonocytic leukemia, but are detected much less often on other types of myeloid leukemia. MY7 is expressed by granulocytes, monocytes, and 5% of normal bone marrow cells. 79% of all acute myeloblastic leukemia (AML) patients tested (72 patients) express MY7 without preferential expression by any AML subtype. MY8 is expressed by normal monocytes, granulocytes, all peroxidase-positive bone marrow cells, and 50% of AML patients. MY3, MY4, and MY8 define myeloid differentiation antigens in that they are not detected on myeloid precursor cells and appear at discrete stages of differentiation. These antigens are not expressed by lymphocytes, erythrocytes, platelets, or lymphoid malignancies. The monoclonal antisera defining these antigens have been used to study differentiation of normal myeloid cells and malignant cell lines. Images PMID:6945311

Concise review: Insights from normal bone remodeling and stem cell-based therapies for bone repair.

PubMed

Khosla, Sundeep; Westendorf, Jennifer J; Mödder, Ulrike I

2010-12-01

There is growing interest in the use of mesenchymal stem cells for bone repair. As a major reason for normal bone remodeling is the removal of fatigue microcracks, advances in our understanding of this process may inform approaches to enhance fracture healing. Increasing evidence now indicates that physiological bone remodeling occurs in close proximity to blood vessels and that these vessels carry perivascular stem cells that differentiate into osteoblasts. Similarly, fracture healing is critically dependent on the ingrowth of blood vessels not only for a nutrient supply but also for the influx of osteoblasts. A number of animal and human studies have now shown the potential benefit of bone marrow-derived mesenchymal stem cells in enhancing bone repair. However, as in other tissues, the question of whether these cells improve fracture healing directly by differentiating into osteoblasts or indirectly by secreting paracrine factors that recruit blood vessels and the accompanying perivascular stem cells remains a major unresolved issue. Moreover, CD34+ cells, which are enriched for endothelial/hematopoietic cells, have also shown efficacy in various bone repair models, at least in part due to the induction of angiogenesis and recruitment of host progenitor cells. Thus, mesenchymal and nonmesenchymal stem/progenitor cells are attractive options for bone repair. It is possible that they contribute directly to bone repair, but it is also likely that they express paracrine factors in the appropriate amounts and combinations that promote and sustain the healing process.

Ectopic bone formation and chondrodysplasia in transgenic mice carrying the rat C3(1)/T{sub AG} fusion gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, J.E.; Maroulakou, I.G.; Anver, M.

Transgenic mice expressing the SV40 large T-antigen (T{sup AG}) under the regultory control of the hormone-responsive rat C3(1) prostatein promoter develop unusual bone and cartilage lesions, as well as ectopic bone and cartilage formation. Two lines of transgenic animals have been propagated in which the expression of the transgene in chondrocytes results in a mild to moderate generalized disorganization of cartilage growth which appears to affect multiple tissues, including the trachea, ear pinna and articular cartilage. The epiphyseal plates are also affected with normal architecture of the zones of proliferation and maturation, but marked elongation of the zone of hypertrophy.more » Immunocytochemistry demonstrates that expression of T{sup AG} is limited to the zone of hypertropny in the epiphyseal plates, suggesting that the chondrocytes become hormone-responsive at this particular stage of differentiation. Normal mineralization and trabecular formation in long bone appears to occur. Ectopic bone and cartilage formation occurs in the foot pads of the fore- and hind- feet over the course of several months. This is preceded by proliferation of sweat gland epithelial cells followed by the appearance of nodules of cartilage and bone. The nodules are closely associated with proliferating epithelium but are not contiguous with bony structures normally found in the feet. The roles of BMP`s, growth factors, oncogenes and hormones in the development of these lesions will be presented. These transgenic animals may provide new insights into hormone-responsiveness of chondrocytes, as well as factors involved in the processes of bone and cartilage differentiation and growth. These transgenic animals may serve as a useful model for human heterotopic bone formation.« less

Emerging treatments for postmenopausal osteoporosis – focus on denosumab

PubMed Central

Geusens, Piet

2009-01-01

The pathway of the receptor activator of the nuclear factor κB ligand (RANKL), RANK and osteoprotegerin (OPG) plays a central role in coupling bone formation and resorption during normal bone turnover and in a wide spectrum of diseases characterized by disturbed bone remodeling, increased bone resorption and bone destruction (osteoporosis, Paget’s disease of bone, rheumatoid arthritis [RA], metastatic bone disease). Clinical trials indicate that denosumab, a RANKL-specific recombinant humanized monoclonal antibody, is effective in suppressing bone resorption, resulting in increase in bone mineral density (BMD) in post-menopausal women with low BMD, and has the potential to prevent progression of erosions in RA and of skeletal-related events in metastatic bone disease. The effects on fracture reduction in postmenopausal osteoporosis are awaited from the recently finished FREEDOM study. In clinical trials with denosumab, overall adverse events were similar to placebo or comparators, indicating a favorable safety profile in these diseases, which until now have been available up to 4 years, but data on long-term safety will be needed. PMID:19554095

Modeling and stress analyses of a normal foot-ankle and a prosthetic foot-ankle complex.

PubMed

Ozen, Mustafa; Sayman, Onur; Havitcioglu, Hasan

2013-01-01

Total ankle replacement (TAR) is a relatively new concept and is becoming more popular for treatment of ankle arthritis and fractures. Because of the high costs and difficulties of experimental studies, the developments of TAR prostheses are progressing very slowly. For this reason, the medical imaging techniques such as CT, and MR have become more and more useful. The finite element method (FEM) is a widely used technique to estimate the mechanical behaviors of materials and structures in engineering applications. FEM has also been increasingly applied to biomechanical analyses of human bones, tissues and organs, thanks to the development of both the computing capabilities and the medical imaging techniques. 3-D finite element models of the human foot and ankle from reconstruction of MR and CT images have been investigated by some authors. In this study, data of geometries (used in modeling) of a normal and a prosthetic foot and ankle were obtained from a 3D reconstruction of CT images. The segmentation software, MIMICS was used to generate the 3D images of the bony structures, soft tissues and components of prosthesis of normal and prosthetic ankle-foot complex. Except the spaces between the adjacent surface of the phalanges fused, metatarsals, cuneiforms, cuboid, navicular, talus and calcaneus bones, soft tissues and components of prosthesis were independently developed to form foot and ankle complex. SOLIDWORKS program was used to form the boundary surfaces of all model components and then the solid models were obtained from these boundary surfaces. Finite element analyses software, ABAQUS was used to perform the numerical stress analyses of these models for balanced standing position. Plantar pressure and von Mises stress distributions of the normal and prosthetic ankles were compared with each other. There was a peak pressure increase at the 4th metatarsal, first metatarsal and talus bones and a decrease at the intermediate cuneiform and calcaneus bones, in prosthetic ankle-foot complex compared to normal one. The predicted plantar pressures and von Misses stress distributions for a normal foot were consistent with other FE models given in the literature. The present study is aimed to open new approaches for the development of ankle prosthesis.

Development, validation and characterization of a novel mouse model of Adynamic Bone Disease (ABD).

PubMed

Ng, Adeline H; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

2014-11-01

The etiology of Adynamic Bone Disease (ABD) is poorly understood but the hallmark of ABD is a lack of bone turnover. ABD occurs in renal osteodystrophy (ROD) and is suspected to occur in elderly patients on long-term anti-resorptive therapy. A major clinical concern of ABD is diminished bone quality and an increased fracture risk. To our knowledge, experimental animal models for ABD other than ROD-ABD have not been developed or studied. The objectives of this study were to develop a mouse model of ABD without the complications of renal ablation, and to characterize changes in bone quality in ABD relative to controls. To re-create the adynamic bone condition, 4-month old female Col2.3Δtk mice were treated with ganciclovir to specifically ablate osteoblasts, and pamidronate was used to inhibit osteoclastic resorption. Four groups of animals were used to characterize bone quality in ABD: Normal bone controls, No Formation controls, No Resorption controls, and an Adynamic group. After a 6-week treatment period, the animals were sacrificed and the bones were harvested for analyses. Bone quality assessments were conducted using established techniques including bone histology, quantitative backscattered electron imaging (qBEI), dual energy X-ray absorptiometry (DXA), microcomputed tomography (microCT), and biomechanical testing. Histomorphometry confirmed osteoblast-related hallmarks of ABD in our mouse model. Bone formation was near complete suppression in the No Formation and Adynamic specimens. Inhibition of bone resorption in the Adynamic group was confirmed by tartrate-resistant acid phosphatase (TRAP) stain. Normal bone mineral density and architecture were maintained in the Adynamic group, whereas the No Formation group showed a reduction in bone mineral content and trabecular thickness relative to the Adynamic group. As expected, the No Formation group had a more hypomineralized profile and the Adynamic group had a higher mean mineralization profile that is similar to suppressed bone turnover in human. This data confirms successful replication of the adynamic bone condition in a mouse without the complication of renal ablation. Our approach is the first model of ABD that uses pharmacological manipulation in a transgenic mouse to mimic the bone cellular dynamics observed in the human ABD condition. We plan to use our mouse model to investigate the adynamic bone condition in aging and to study changes to bone quality and fracture risk as a consequence of over-suppressed bone turnover. Copyright © 2014 Elsevier Inc. All rights reserved.

Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration

NASA Astrophysics Data System (ADS)

Dezawa, Mari; Ishikawa, Hiroto; Itokazu, Yutaka; Yoshihara, Tomoyuki; Hoshino, Mikio; Takeda, Shin-ichi; Ide, Chizuka; Nabeshima, Yo-ichi

2005-07-01

Bone marrow stromal cells (MSCs) have great potential as therapeutic agents. We report a method for inducing skeletal muscle lineage cells from human and rat general adherent MSCs with an efficiency of 89%. Induced cells differentiated into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. The induced population contained Pax7-positive cells that contributed to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. These MSCs represent a more ready supply of myogenic cells than do the rare myogenic stem cells normally found in muscle and bone marrow.

The character of gene expression of human periosteum used to form new tissue in allograft bone.

PubMed

Kemppainen, Jessica; Yu, Qing; Alexander, John; Jacquet, Robin; Scharschmidt, Thomas; Landis, William

2014-08-01

Of more than 2 million segmental bone defects repaired annually with bone autografts and allografts, 15-40% fail. Improving healing rates may be approached with tissue engineering and use of periosteum overlying an allograft. The present study documents gene expression in human periosteum-allograft constructs compared to allografts alone. Strips of human cadaveric periosteum (26 years, f, distal femur) were sutured about sterilized human femoral cortical strut bone allograft (54 years, m) segments. After construct incubation (M199 supplemented medium) for 8 d, constructs and allografts alone were implanted in nude mice. At 10 and 20 weeks, constructs (N = 4, each group) and allografts (N = 2, each group) were retrieved and placed in RNAlater for quantitative PCR to determine expression of human- and murine-specific genes relevant to remodeling. Specimens were frozen-ground to powders and RNA was extracted, purified, reverse-transcribed, and amplified. Ribosomal protein (P0) was used to normalize sample quantities. Fold change plots were generated following statistical analyses comparing 20- to 10-week gene expression data. Allografts alone yielded no human-specific gene expression. Notable fold changes of human-specific alkaline phosphatase, bone sialoprotein, type I collagen, decorin, RANKL, RANK, cathepsin K, and osteocalcin in 20-week compared to 10-week specimens were found. Murine-specific expression of genes indicative of host mouse vascularization (RANK, type I collagen) was detected in both allograft alone and periosteum-allograft samples. Gene data confirm viable periosteum in constructs after 20 weeks. Relatively higher fold-change values of RANK, RANKL and cathepsin K indicate activities of osteoclast precursors, osteoclasts and osteoblasts involved in allograft remodeling during implantation. All additional genes of interest indicate osteoblast activity in new bone matrix formation. Gene data are directly correlated with previous and present histology work. The results of this study suggest that further investigations could help to establish whether autologous periosteum-allograft constructs could be used for the repair of bone defects.

Elevated Vitamin D Receptor Levels in Genetic Hypercalciuric Stone-Forming Rats Are Associated With Downregulation of Snail

PubMed Central

Bai, Shaochun; Wang, Hongwei; Shen, Jikun; Zhou, Randal; Bushinsky, David A; Favus, Murray J

2010-01-01

Patients with idiopathic hypercalciuria (IH) and genetic hypercalciuric stone-forming (GHS) rats, an animal model of IH, are both characterized by normal serum Ca, hypercalciuria, Ca nephrolithiasis, reduced renal Ca reabsorption, and increased bone resorption. Serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels are elevated or normal in IH and are normal in GHS rats. In GHS rats, vitamin D receptor (VDR) protein levels are elevated in intestinal, kidney, and bone cells, and in IH, peripheral blood monocyte VDR levels are high. The high VDR is thought to amplify the target-tissue actions of normal circulating 1,25(OH)2D levels to increase Ca transport. The aim of this study was to elucidate the molecular mechanisms whereby Snail may contribute to the high VDR levels in GHS rats. In the study, Snail gene expression and protein levels were lower in GHS rat tissues and inversely correlated with VDR gene expression and protein levels in intestine and kidney cells. In human kidney and colon cell lines, ChIP assays revealed endogenous Snail binding close to specific E-box sequences within the human VDR promoter region, whereas only one E-box specifically bound Snail in the rat promoter. Snail binding to rat VDR promoter E-box regions was reduced in GHS compared with normal control intestine and was accompanied by hyperacetylation of histone H3. These results provide evidence that elevated VDR in GHS rats likely occurs because of derepression resulting from reduced Snail binding to the VDR promoter and hyperacetylation of histone H3. © 2010 American Society for Bone and Mineral Research. PMID:19929616

Inhibition of colony-stimulating-factor-1 signaling in vivo with the orally bioavailable cFMS kinase inhibitor GW2580.

PubMed

Conway, James G; McDonald, Brad; Parham, Janet; Keith, Barry; Rusnak, David W; Shaw, Eva; Jansen, Marilyn; Lin, Peiyuan; Payne, Alan; Crosby, Renae M; Johnson, Jennifer H; Frick, Lloyd; Lin, Min-Hwa Jasmine; Depee, Scott; Tadepalli, Sarva; Votta, Bart; James, Ian; Fuller, Karen; Chambers, Timothy J; Kull, Frederick C; Chamberlain, Stanley D; Hutchins, Jeff T

2005-11-01

Colony-stimulating-factor-1 (CSF-1) signaling through cFMS receptor kinase is increased in several diseases. To help investigate the role of cFMS kinase in disease, we identified GW2580, an orally bioavailable inhibitor of cFMS kinase. GW2580 completely inhibited human cFMS kinase in vitro at 0.06 microM and was inactive against 26 other kinases. GW2580 at 1 microM completely inhibited CSF-1-induced growth of mouse M-NFS-60 myeloid cells and human monocytes and completely inhibited bone degradation in cultures of human osteoclasts, rat calvaria, and rat fetal long bone. In contrast, GW2580 did not affect the growth of mouse NS0 lymphoblastoid cells, human endothelial cells, human fibroblasts, or five human tumor cell lines. GW2580 also did not affect lipopolysaccharide (LPS)-induced TNF, IL-6, and prostaglandin E2 production in freshly isolated human monocytes and mouse macrophages. After oral administration, GW2580 blocked the ability of exogenous CSF-1 to increase LPS-induced IL-6 production in mice, inhibited the growth of CSF-1-dependent M-NFS-60 tumor cells in the peritoneal cavity, and diminished the accumulation of macrophages in the peritoneal cavity after thioglycolate injection. Unexpectedly, GW2580 inhibited LPS-induced TNF production in mice, in contrast to effects on monocytes and macrophages in vitro. In conclusion, GW2580's selective inhibition of monocyte growth and bone degradation is consistent with cFMS kinase inhibition. The ability of GW2580 to chronically inhibit CSF-1 signaling through cFMS kinase in normal and tumor cells in vivo makes GW2580 a useful tool in assessing the role of cFMS kinase in normal and disease processes.

Effect of human milk on blood and bone marrow cells in a malnourished mice model; comparative study with cow milk.

PubMed

García, Isabel; Salva, Susana; Zelaya, Hortensia; Villena, Julio; Agüero, Graciela

2013-11-01

It has been demonstrated that the alterations caused by nutrient deficiency can be reverted by adequate nutritional repletion. To perform comparative studies between human and cow milks in order to evaluate the impact of both milks on the recovery of blood and bone marrow cells affected in malnourished mice. Weaned mice were malnourished after consuming a protein free diet for 21 days. Malnourished mice received cow or human milk (CM or HM) for 7 or 14 consecutive days. During the period of administration of milk, the mice consumed the protein free diet ad libitum. The malnourished control (MNC) group received only protein free diet whereas the wellnourished control (WNC) mice consumed the balanced conventional diet. Both milks normalized serum albumin levels and improved thymus weight. Human milk was less effective than cow milk to increase body weight and serum transferrin levels. In contrast, human milk was more effective than cow milk to increase the number of leukocytes (WNC: 6.90 ± 1.60a; MNC: 2.80 ± 0.90b; CM 7d: 3.74 ± 1.10b; HM 7d: 7.16 ± 1.90a; CM 14d: 4.35 ± 1.20b; HM 14d: 6.75 ± 1.20a (109/L); p < 0.05) and lymphocytes (WNC: 5.80 ± 0.36a; MNC: 1.80 ± 0.40b; CM 7d: 2.50 ± 0.30b; HM 7d: 4.20 ± 0.50c; CM 14d: 3.30 ± 0.31d; HM 14d: 4.70 ± 0.28c (109/L); p < 0.05) in peripheral blood. Both milks induced an increment in mitotic pool cells in bone marrow and α-naphthyl butyrate esterase positive cells in peripheral blood. They also normalized phagocytic function in blood neutrophils and oxidative burst in peritoneal cells. Both milks were equally effective to exert favorable effects on the number of the bone marrow cells and the functions of the blood and peritoneal cells involved in immune response. However, only human milk normalized the number of leukocytes and increased the number of neutrophils in peripheral blood. Copyright AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

Adenovirus 36, Adiposity, and Bone Strength in Late-Adolescent Females

PubMed Central

Laing, Emma M; Tripp, Ralph A; Pollock, Norman K; Baile, Clifton A; Della-Fera, Mary Anne; Rayalam, Srujana; Tompkins, Stephen M; Keys, Deborah A; Lewis, Richard D

2017-01-01

Adenovirus 36 (Ad36) is the only adenovirus to date that has been linked with obesity in humans. Our previous studies in late-adolescent females suggest that excess weight in the form of fat mass is associated with lower cortical bone strength. The purpose of this study was to assess the relationship between Ad36-specific antibodies, adiposity, and bone strength in our sample of late-adolescent females. A cross-sectional study of 115 females aged 18 to 19 years was performed. Participants were classified according to adiposity by dual-energy X-ray absorptiometry (body fat percentage as normal-fat [<32% body fat; n=93] or high-fat [≥ 32% body fat; n=22]), and according to the presence of Ad36-specific neutralizing antibodies. Peripheral quantitative computed tomography measured bone parameters at the 4% (trabecular bone) and 20% (cortical bone) site, and muscle cross-sectional area (MCSA) at the 66% site, from the distal metaphyses of the radius and the tibia. Bone strength was determined from volumetric bone mineral density and bone geometry to calculate bone strength index (BSI; trabecular site) and polar strength–strain index (SSI; cortical site). After adjustment for MCSA and limb length, radial SSI was lower in Ad36+ versus Ad36− subjects from the high-fat group (p<0.03), but not the normal-fat group. No significant differences were observed between groups in tibial SSI or BSI. These data support an association of adiposity and cortical bone strength at the radius with the presence of neutralizing antibodies to Ad36 in late-adolescent females. PMID:23296755

Blockade of CD26 signaling inhibits human osteoclast development.

PubMed

Nishida, Hiroko; Suzuki, Hiroshi; Madokoro, Hiroko; Hayashi, Mutsumi; Morimoto, Chikao; Sakamoto, Michiie; Yamada, Taketo

2014-11-01

Bone remodeling is maintained by the delicate balance between osteoblasts (OBs) and osteoclasts (OCs). However, the role of CD26 in regulating bone remodeling has not yet been characterized. We herein show that CD26 is preferentially expressed on normal human OCs and is intensely expressed on activated human OCs in osteolytic bone alterations. Macrophage-colony stimulating factor (M-CSF) and soluble receptor activator of NF-κB ligand (sRANKL) induced human OC differentiation, in association with CD26 expression on monocyte-macrophage lineage cells. CD26 expression was accompanied by increased phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), which is crucial for early human OC differentiation. The humanized anti-CD26 monoclonal antibody, huCD26mAb, impaired the formation and function of tartrate-resistant acid phosphatase (TRAP)/CD26 positive multi-nucleated (nuclei > 3) OCs with maturation in the manner of dose-dependency. It was revealed that huCD26mAb inhibits early OC differentiation via the inactivation of MKK3/6, p38 MAPK and subsequent dephosphorylation of microphthalmia-associated transcription factor (mi/Mitf). These inhibitions occur immediately after RANKL binds to RANK on the human OC precursor cells and were demonstrated using the OC functional assays. huCD26mAb subsequently impaired OC maturation and bone resorption by suppressing the expression of TRAP and OC fusion proteins. In addition, p38 MAPK inhibitor also strongly inhibited OC formation and function. Our results suggest that the blockade of CD26 signaling impairs the development of human functional OCs by inhibiting p38 MAPK-mi/Mitf phosphorylation pathway and that targeting human OCs with huCD26mAb may have therapeutic potential for the treatment of osteolytic lesions following metastasis to alleviate bone destruction and reduce total skeletal-related events (SREs). © 2014 American Society for Bone and Mineral Research.

Connective tissue growth factor and bone morphogenetic protein 2 are induced following myocardial ischemia in mice and humans.

PubMed

Rutkovskiy, Arkady; Sagave, Julia; Czibik, Gabor; Baysa, Anton; Zihlavnikova Enayati, Katarina; Hillestad, Vigdis; Dahl, Christen Peder; Fiane, Arnt; Gullestad, Lars; Gravning, Jørgen; Ahmed, Shakil; Attramadal, Håvard; Valen, Guro; Vaage, Jarle

2017-09-01

We aimed to study the cardiac expression of bone morphogenetic protein 2, its receptor 1 b, and connective tissue growth factor, factors implicated in cardiac embryogenesis, following ischemia/hypoxia, heart failure, and in remodeling hearts from humans and mice. Biopsies from the left ventricle of patients with end-stage heart failure due to dilated cardiomyopathy or coronary artery disease were compared with donor hearts and biopsies from patients with normal heart function undergoing coronary artery bypass grafting. Mouse model of post-infarction remodeling was made by permanent ligation of the left coronary artery. Hearts were analyzed by real-time polymerase chain reaction and Western blotting after 24 hours and after 2 and 4 weeks. Patients with dilated cardiomyopathy and mice post-infarction had increased cardiac expression of connective tissue growth factor. Bone morphogenetic protein 2 was increased in human hearts failing due to coronary artery disease and in mice post-infarction. Gene expression of bone morphogenetic protein receptor 1 beta was reduced in hearts of patients with failure, but increased two weeks following permanent ligation of the left coronary artery in mice. In conclusion, connective tissue growth factor is upregulated in hearts of humans with dilated cardiomyopathy, bone morphogenetic protein 2 is upregulated in remodeling due to myocardial infarction while its receptor 1 b in human failing hearts is downregulated. A potential explanation might be an attempt to engage regenerative processes, which should be addressed by further, mechanistic studies.

Cementogenic potential of multipotential mesenchymal stem cells purified from the human periodontal ligament.

PubMed

Torii, Daisuke; Konishi, Kiyoshi; Watanabe, Nobuyuki; Goto, Shinichi; Tsutsui, Takeki

2015-01-01

The periodontal ligament (PDL) consists of a group of specialized connective tissue fibers embedded in the alveolar bone and cementum that are believed to contain progenitors for mineralized tissue-forming cell lineages. These progenitors may contribute to regenerative cell therapy or tissue engineering methods aimed at recovery of tissue formation and functions lost in periodontal degenerative changes. Some reports using immortal clonal cell lines of cementoblasts, which are cells containing mineralized tissue-forming cell lineages, have shown that their phenotypic alteration and gene expression are associated with mineralization. Immortal, multipotential PDL-derived cell lines may be useful biological tools for evaluating differentiation-inducing agents. In this study, we confirmed the gene expression and mineralization potential of primary and immortal human PDL cells and characterized their immunophenotype. Following incubation with mineralization induction medium containing β-glycerophosphate, ascorbic acid, and dexamethasone, normal human PDL (Pel) cells and an immortal derivative line (Pelt) cells showed higher levels of mineralization compared with cells grown in normal growth medium. Both cell types were positive for putative surface antigens of mesenchymal cells (CD44, CD73, CD90, and CD105). They were also positive for stage-specific embryonic antigen-3, a marker of multipotential stem cells. Furthermore, PDL cells expressed cementum attachment protein and cementum protein 1 when cultured with recombinant human bone morphogenetic protein-2 or -7. The results suggest that normal and immortal human PDL cells contain multipotential mesenchymal stem cells with cementogenic potential.

Hardness of the subchondral bone of the patella in the normal state, in chondromalacia, and in osteoarthrosis.

PubMed

Björkström, S; Goldie, I F

1982-06-01

The hardness of bone is its property of withstanding the impact of a penetrating agent. It has been found that articular degenerative changes in, for example, the tibia (knee) are combined with a decrease in the hardness of the subchondral bone. In this investigation the hardness of subchondral bone in chondromalacia and osteoarthrosis of the patella has been analysed and compared with normal subchondral bone. Using an indentation method originally described by Brinell the hardness of the subchondral bone was evaluated in 7 normal patellae, in 20 with chondromalacia and in 33 with osteoarthrosis. A microscopic and microradiographic study of the subchondral bone was carried out simultaneously. Hardness was lowest in the normal material. The mean hardness value beneath the degenerated cartilage differed only slightly from that of the normal material, but the variation of values was increased. The hardness in bone in the chondromalacia area was lower than the hardness in bone covered by surrounding normal cartilage. The mean hardness value in bone beneath normal parts of cartilage in specimens with chondromalacia was higher than the mean hardness value of the normal material. In the microscopic and microradiographic examination it became evident that there was a relationship between trabecular structure and subchondral bone hardness; high values: coarse and solid structure; low values: slender and less regular structure.

Insulin-producing Cells from Adult Human Bone Marrow Mesenchymal Stromal Cells Could Control Chemically Induced Diabetes in Dogs: A Preliminary Study.

PubMed

Gabr, Mahmoud M; Zakaria, Mahmoud M; Refaie, Ayman F; Ismail, Amani M; Khater, Sherry M; Ashamallah, Sylvia A; Azzam, Maha M; Ghoneim, Mohamed A

2018-01-01

Ten mongrel dogs were used in this study. Diabetes was chemically induced in 7 dogs, and 3 dogs served as normal controls. For each diabetic dog, 5 million human bone marrow-derived mesenchymal stem cells/kg were differentiated to form insulin-producing cells using a trichostatin-based protocol. Cells were then loaded in 2 TheraCyte capsules which were transplanted under the rectus sheath. One dog died 4 d postoperatively from pneumonia. Six dogs were followed up with for 6 to 18 mo. Euglycemia was achieved in 4 dogs. Their glucose tolerance curves exhibited a normal pattern demonstrating that the encapsulated cells were glucose sensitive and insulin responsive. In the remaining 2 dogs, the fasting blood sugar levels were reduced but did not reach normal values. The sera of all transplanted dogs contained human insulin and C-peptide with a negligible amount of canine insulin. Removal of the transplanted capsules was followed by prompt return of diabetes. Intracytoplasmic insulin granules were seen by immunofluorescence in cells from the harvested capsules. Furthermore, all pancreatic endocrine genes were expressed. This study demonstrated that the TheraCyte capsule or a similar device can provide adequate immunoisolation, an important issue when stem cells are considered for the treatment of type 1 diabetes mellitus.

Modulation of insulin-like growth factor 1 levels in human osteoarthritic subchondral bone osteoblasts.

PubMed

Massicotte, Frédéric; Fernandes, Julio Cesar; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Lajeunesse, Daniel

2006-03-01

Human osteoarthritis (OA) is characterized by cartilage loss, bone sclerosis, osteophyte formation and inflammation of the synovial membrane. We previously reported that OA osteoblasts (Ob) show abnormal phenotypic characteristics possibly responsible for bone sclerosis and that two subgroups of OA patients can be identified by low or high endogenous production of prostaglandin E2 (PGE2) by OA Ob. Here, we determined that the elevated PGE2 levels in the high OA subgroup were linked with enhanced cyclooxygenase-2 (COX-2) protein levels compared to normal and low OA Ob. A linear relationship was observed between endogenous PGE2 levels and insulin-like growth factor 1 (IGF-1) levels in OA Ob. As parathyroid hormone (PTH) and PGE2 are known stimulators of IGF-1 production in Ob, we next evaluated their effect in OA Ob. Both subgroups increased their IGF-1 production similarly in response to PGE2, while the high OA subgroup showed a blunted response to PTH compared to the low OA group. Conversely, only the high OA group showed a significant inhibition of IGF-1 production when PGE2 synthesis was reduced with Naproxen, a non-steroidal antiinflammatory drug (NSAID) that inhibits cyclooxygenases (COX). The PGE2-dependent stimulation of IGF-1 synthesis was due in part to the cAMP/protein kinase A pathway since both the direct inhibition of this pathway with H-89 and the inhibition of EP2 or EP4 receptors, linked to cAMP production, reduced IGF-1 synthesis. The production of the most abundant IGF-1 binding proteins (IGFBPs) in bone tissue, IGFBP-3, -4, and -5, was lower in OA compared to normal Ob independently of the OA group. Under basal condition, OA Ob expressed similar IGF-1 mRNA to normal Ob; however, PGE2 stimulated IGF-1 mRNA expression more in OA than normal Ob. These data suggest that increased IGF-1 levels correlate with elevated endogenous PGE2 levels in OA Ob and that higher IGF-1 levels in OA Ob could be important for bone sclerosis in OA.

Applicability of strain measurements on a contra angle handpiece for the determination of alveolar bone quality during dental implant surgery.

PubMed

Krafft, Tim; Winter, Werner; Wichmann, Manfred; Karl, Matthias

2012-07-01

Alveolar bone quality is considered to be an important prognostic factor in dental implant stability. Although numerous methods have been described, no technique allows for reliable diagnostics. The purpose of this study was to determine if strain measurements on the shaft of a contra angle handpiece during implant bed preparation could be used for the determination of bone quality. Experiments in polyurethane foam and human cadaver bone were conducted to investigate whether strain measurements could be correlated with other diagnostic parameters, such as the surgeon's tactile sensation during drilling, implant insertion torque, implant stability, elastic modulus of bone and bone quality as assessed radiographically. Tests were also performed to determine if strain measurements could be used to distinguish various types of bone. As axial feed and contact pressure during the drilling process could not be standardized under simulated clinical conditions, substantial deviations in the time needed to complete the drilling occurred. Under controlled circumstances using polyurethane foam, this problem could be addressed by a normalization procedure, but great variations occurred in human cadaver bone. As bone quality could not be reliably determined, especially when a cortical layer was present, strain measurements on a contra angle handpiece appears to be inappropriate for this purpose. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Potential effects of a low-molecular-weight fucoidan extracted from brown algae on bone biomaterial osteoconductive properties.

PubMed

Changotade, S Igondjo Tchen; Korb, G; Bassil, J; Barroukh, B; Willig, C; Colliec-Jouault, S; Durand, P; Godeau, G; Senni, K

2008-12-01

In this work, we first tested the influence of low-molecular-weight (LMW) fucoidan extracted from pheophicae cell wall on bidimensional cultured normal human osteoblasts' behaviors. Second, by impregnation procedure with LMW fucoidan of bone biomaterial (Lubboc), we explored in this bone extracellular matrix context its capabilities to support human osteoblastic behavior in 3D culture. In bidimensionnal cultures, we evidenced that LMW fucoidan promotes human osteoblast proliferation and collagen type I expression and favors precocious alkaline phosphatase activity. Furthermore, with LMW fucoidan, von Kossa's staining was positive at 30 days and positive only at 45 days in the absence of LMW fucoidan. In our three-dimensional culture models with the biomaterial pretreated with LMW fucoidan, osteoblasts promptly overgrew the pretreated biomaterial. We also evidenced that osteoblasts increased proliferation with pretreated biomaterial when compared with untreated biomaterial. Osteoblasts secreted osteocalcin and expressed BMP2 receptor on control material as well as with LMW fucoidan impregnated biomaterial. In conclusion, in our experimental conditions, LMW fucoidan stimulated expression of osteoblastic markers differentiation such as alkaline phosphatase activity, collagen type I expression, and mineral deposition; furthermore, cell proliferation was favored. These findings suggest that fucoidan could be clinically useful for bone regeneration and bone substitute design. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.

Microgravity Stress: Bone and Connective Tissue.

PubMed

Bloomfield, Susan A; Martinez, Daniel A; Boudreaux, Ramon D; Mantri, Anita V

2016-03-15

The major alterations in bone and the dense connective tissues in humans and animals exposed to microgravity illustrate the dependency of these tissues' function on normal gravitational loading. Whether these alterations depend solely on the reduced mechanical loading of zero g or are compounded by fluid shifts, altered tissue blood flow, radiation exposure, and altered nutritional status is not yet well defined. Changes in the dense connective tissues and intervertebral disks are generally smaller in magnitude but occur more rapidly than those in mineralized bone with transitions to 0 g and during recovery once back to the loading provided by 1 g conditions. However, joint injuries are projected to occur much more often than the more catastrophic bone fracture during exploration class missions, so protecting the integrity of both tissues is important. This review focuses on the research performed over the last 20 years in humans and animals exposed to actual spaceflight, as well as on knowledge gained from pertinent ground-based models such as bed rest in humans and hindlimb unloading in rodents. Significant progress has been made in our understanding of the mechanisms for alterations in bone and connective tissues with exposure to microgravity, but intriguing questions remain to be solved, particularly with reference to biomedical risks associated with prolonged exploration missions. Copyright © 2016 John Wiley & Sons, Inc.

Bone morphogenetic protein 4 and bone morphogenetic protein receptor expression in the pituitary gland of adult dogs in healthy condition and with ACTH-secreting pituitary adenoma.

PubMed

Sato, A; Ochi, H; Harada, Y; Yogo, T; Kanno, N; Hara, Y

2017-01-01

The purpose of this study was to investigate the expression of bone morphogenetic protein 4 (BMP4) and its receptors, bone morphogenetic protein receptor I (BMPRI) and BMPRII, in the pituitary gland of healthy adult dogs and in those with ACTH-secreting pituitary adenoma. Quantitative polymerase chain reaction analysis showed that the BMP4 messenger RNA expression level in the ACTH-secreting pituitary adenoma samples was significantly lower than that in the normal pituitary gland samples (P = 0.03). However, there were no statistically significant differences between samples with respect to the messenger RNA expression levels of the receptors BMPRIA, BMPRIB, and BMPRII. Double-immunofluorescence analysis of the normal canine pituitary showed that BMP4 was localized in the thyrotroph (51.3 ± 7.3%) and not the corticotroph cells. By contrast, BMPRII was widely expressed in the thyrotroph (19.9 ± 5.2%) and somatotroph cells (94.7 ± 3.6%) but not in the corticotroph cells (P < 0.001, thyrotroph cells vs somatotroph cells). Similarly, in ACTH-secreting pituitary adenoma, BMP4 and BMPRII were not expressed in the corticotroph cells. Moreover, the percentage of BMP4-positive cells was also significantly reduced in the thyrotroph cells of the surrounding normal pituitary tissue obtained from the resected ACTH-secreting pituitary adenoma (8.3 ± 7.9%) compared with that in normal canine pituitary (P < 0.001). BMP4 has been reported to be expressed in corticotroph cells in the human pituitary gland. Therefore, the results of this study reveal a difference in the cellular pattern of BMP4-positive staining in the pituitary gland between humans and dogs and further revealed the pattern of BMPRII-positive staining in the dog pituitary gland. These species-specific differences regarding BMP4 should be considered when using dogs as an animal model for Cushing's disease. Copyright © 2015 Elsevier Inc. All rights reserved.

An Evaluation of the Surgical Trauma to Intracochlear Structures After Insertion of Cochlear Implant Electrode Arrays: A Comparison by Round Window and Antero-Inferior Cochleostomy Techniques.

PubMed

Sikka, Kapil; Kairo, Arvind; Singh, Chirom Amit; Roy, T S; Lalwani, Sanjeev; Kumar, Rakesh; Thakar, Alok; Sharma, Suresh C

2017-09-01

To evaluate the extent of intracochlear damage by histologic assessment of cadaveric temporal bones after insertion of cochlear implants by: round window approach and cochleostomy approach. Cochlear implantation was performed by transmastoid facial recess approach in 10 human cadaveric temporal bones. In 5 temporal bones, electrode insertion was acheieved by round window approach and in the remaining 5 bones, by cochleostomy approach. The bones were fixed, decalcified, sectioned and studied histologically. Grading of insertion trauma was assessed. In the round window insertion group, 2 bones had to be excluded from the study: one was damaged during handling with electrode extrusion and another bone did not show any demonstrable identifiable cochlear structure. Out of the 3 temporal bones, a total of 35 sections were examined: 24 demonstrated normal cochlea, 4 had basilar membrane bulging and 7 had fracture of bony spiral lamina. In the cochleostomy group, histology of 2 bones had to be discarded due to lack of any identifiable inner ear structures. Out of the 3 bones studied, 18 sections were examined: only 3 were normal, 4 sections had some bulge in spiral lamina and 11 had fracture of bony spiral lamina. The fracture of spiral lamina and bulge of basement membrane proportion is relatively higher if we perform cochleostomy as compared to round window approach. Therefore, round window insertion is relatively less traumatic as compared to cochleostomy. However, our sample size was very small and a study with a larger sample is required to further validate these findings.

Cellular therapy in bone-tendon interface regeneration

PubMed Central

Rothrauff, Benjamin B; Tuan, Rocky S

2014-01-01

The intrasynovial bone-tendon interface is a gradual transition from soft tissue to bone, with two intervening zones of uncalcified and calcified fibrocartilage. Following injury, the native anatomy is not restored, resulting in inferior mechanical properties and an increased risk of re-injury. Recent in vivo studies provide evidence of improved healing when surgical repair of the bone-tendon interface is augmented with cells capable of undergoing chondrogenesis. In particular, cellular therapy in bone-tendon healing can promote fibrocartilage formation and associated improvements in mechanical properties. Despite these promising results in animal models, cellular therapy in human patients remains largely unexplored. This review highlights the development and structure-function relationship of normal bone-tendon insertions. The natural healing response to injury is discussed, with subsequent review of recent research on cellular approaches for improved healing. Finally, opportunities for translating in vivo findings into clinical practice are identified. PMID:24326955

Effect of insertion torque on bone screw pullout strength.

PubMed

Lawson, K J; Brems, J

2001-05-01

The effect of insertion torque on the holding strength of 4.5-mm ASIF/AO cortical bone screws was studied in vitro. Screw holding strength was determined using an Instron materials testing machine (Bristol, United Kingdom) on 55 lamb femora and 30 human tibiocortical bone sections. Holding strength was defined as tensile stress at pullout with rapid loading to construct failure. Different insertion torques were tested, normalizing to the thickness of cortical bone specimen engaged. These represented low, intermediate, high, and thread-damaging insertion torque. All screws inserted with thread-damaging torque and single cortex engaging screws inserted to high torque tightening moments showed diminished holding strength. This loss of strength amounted to 40%-50% less than screws inserted with less torque.

Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis.

PubMed

Huang, Le; You, Yong-Ke; Zhu, Tracy Y; Zheng, Li-Zhen; Huang, Xiao-Ru; Chen, Hai-Yong; Yao, Dong; Lan, Hui-Yao; Qin, Ling

2016-06-10

This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p < 0.05). However the indices measured at proximal tibia showed comparable trabecular BMD and microarchitecture among the four groups. Femur length in crp/db/db group was significantly shorter than db/m group (p < 0.05) and cortices were thinner in db/db and crp/db/db groups (p > 0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.

Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis

NASA Astrophysics Data System (ADS)

Huang, Le; You, Yong-Ke; Zhu, Tracy Y.; Zheng, Li-Zhen; Huang, Xiao-Ru; Chen, Hai-Yong; Yao, Dong; Lan, Hui-Yao; Qin, Ling

2016-06-01

This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p < 0.05). However the indices measured at proximal tibia showed comparable trabecular BMD and microarchitecture among the four groups. Femur length in crp/db/db group was significantly shorter than db/m group (p < 0.05) and cortices were thinner in db/db and crp/db/db groups (p > 0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.

Occurrence and pattern of long bone fractures in growing dogs with normal and osteopenic bones.

PubMed

Kumar, K; Mogha, I V; Aithal, H P; Kinjavdekar, P; Singh, G R; Pawde, A M; Kushwaha, R B

2007-11-01

A retrospective study was undertaken to record the occurrence and pattern of long bone fractures, and the efficacy of Intramedullary (IM) Steinmann pin fixing in growing dogs. All the records of growing dogs during a 10-year-period were screened to record the cause of trauma, the age and sex of the animal, the bone involved, the type and location of the fracture, the status of fixation, alignment, maintenance of fixation and fracture healing. The results were analysed and comparisons were made between growing dogs with normal and osteopenic bones. Among the 310 cases of fractures recorded, the bones were osteopenic in 91 cases (29%). Minor trauma was the principal cause of fracture in dogs with osteopenia (25%), and indigenous breeds were most commonly affected (38%). Fractures in dogs with osteopenic bones were most commonly recorded in the age group of 2-4 months (53%), whereas fractures in normal dogs were almost equally distributed between 2 and 8 months of age. Male dogs were affected significantly more often in both groups. In osteopenic bones, most fractures were recorded in the femur (56%), and they were distributed equally along the length of the bone. Whereas in normal bones, fractures were almost equally distributed in radius/ulna, femur and tibia, and were more often recorded at the middle and distal third of long bones. Oblique fractures were most common in both groups; however, comminuted fractures were more frequent in normal bones, whereas incomplete fractures were more common in osteopenic bones. Ninety-nine fracture cases treated with IM pinning (66 normal, 33 osteopenic) were evaluated for the status of fracture reduction and healing. In a majority of the cases (61%) with osteopenic bones, the diameter of the pin was relatively smaller than the diameter of the medullary cavity (<70-75%), whereas in 68% of the cases in normal bones the pin diameter was optimum. The status of fracture fixing was satisfactory to good in significantly more osteonormal (59%) than osteopenic dogs (42%). Fracture healing, however, was satisfactory in significantly more cases with osteopenic than normal bones. The appearance of callus was relatively early and the amount of bridging callus was relatively large in greater number of osteopenic bone fractures. Mal-union and non-union were recorded more often in osteopenic cases than in normal cases. However, the incidence of bone shortening and osteomyelitis was significantly higher in normal bones than in osteopenic bones.

Excess TGF-β mediates muscle weakness associated with bone metastases in mice

PubMed Central

Reiken, Steven; Xie, Wenjun; Andersson, Daniel C.; John, Sutha; Chiechi, Antonella; Wright, Laura E.; Umanskaya, Alisa; Niewolna, Maria; Trivedi, Trupti; Charkhzarrin, Sahba; Khatiwada, Pooja; Wronska, Anetta; Haynes, Ashley; Benassi, Maria Serena; Witzmann, Frank A.; Zhen, Gehua; Wang, Xiao; Cao, Xu; Roodman, G. David; Marks, Andrew R.; Guise, Theresa A.

2015-01-01

Cancer-associated muscle weakness is poorly understood and there is no effective treatment. Here, we find that seven different mouse models of human osteolytic bone metastases, representing breast, lung and prostate cancers, as well as multiple myeloma exhibited impaired muscle function, implicating a role for the tumor-bone microenvironment in cancer-associated muscle weakness. We found that TGF-β, released from the bone surface as a result of metastasis-induced bone destruction upregulated NADPH oxidase 4 (Nox4), resulting in elevated oxidization of skeletal muscle proteins, including the ryanodine receptor/calcium (Ca2+) release channel (RyR1). The oxidized RyR1 channels leaked Ca2+, resulting in lower intracellular signaling required for proper muscle contraction. We found that inhibiting RyR1 leak, TGF-β signaling, TGF-β release from bone or Nox4 all improved muscle function in mice with MDA-MB-231 bone metastases. Humans with breast cancer- or lung cancer-associated bone metastases also had oxidized skeletal muscle RyR1 that is not seen in normal muscle. Similarly, skeletal muscle weakness, higher levels of Nox4 protein and Nox4 binding to RyR1, and oxidation of RyR1 were present in a mouse model of Camurati-Engelmann disease, a non-malignant metabolic bone disorder associated with increased TGF-β activity. Thus, metastasis-induced TGF-β release from bone contributes to muscle weakness by decreasing Ca2+-induced muscle force production. PMID:26457758

Concise Review: Personalized Human Bone Grafts for Reconstructing Head and Face

PubMed Central

Bhumiratana, Sarindr

2012-01-01

Regeneration of normal shape, architecture, and function of craniofacial tissues following congenital abnormality, trauma, or surgical treatment presents special problems to tissue engineering. Because of the great variations in properties of these tissues, currently available treatment options fall short of adequate care. We propose that the engineering of personalized bone graft customized to the patient and the specific clinical condition would revolutionize the way we currently treat craniofacial defects and discuss some of the current and emerging treatment modalities. PMID:23197642

Effects of combined hydroxyapatite and human platelet rich plasma on bone healing in rabbit model: radiological, macroscopical, hidtopathological and biomechanical evaluation.

PubMed

Oryan, A; Meimandi Parizi, A; Shafiei-Sarvestani, Z; Bigham, A S

2012-12-01

Hydroxyapatite is an osteoconductive material used as a bone graft extender and exhibits excellent biocompatibility with soft tissues such as skin, muscle and gums, making it an ideal candidate for orthopedic and dental implants or components of implants. Synthetic hydroxyapatite has been widely used in repair of hard tissues, and common uses include bone repair, bone augmentation, as well as coating of implants or acting as fillers in bone or teeth. On the other hand, human platelet rich plasma (hPRP) has been used as a source of osteoinductive factor. A combination of hPRP and hydroxyapatite is expected to create a composite with both osteoconductive and osteoinductive properties. This study examined the effect of a combination of hydroxyapatite and hPRP on osteogenesis in vivo, using rabbit model bone healing. A critical size defect of 10 mm long was created in the radial diaphysis of 36 rabbit and either supplied with hydroxyapatite-human PRP or hydroxyapatite or was left empty (control group). Radiographs of each forelimb were taken postoperatively on 1st day and then at the 2nd, 4th, 6th and 8th weeks post injury to evaluate bone formation, union and remodeling of the defect. The operated radiuses of half of the animals in each group were removed on 56th postoperative day and were grossly and histopathologically evaluated. In addition, biomechanical test was conducted on the operated and normal forearms of the other half of the animals of each group. This study demonstrated that hydroxyapatite-humanPRP, could promote bone regeneration in critical size defects with a high regenerative capacity. The results of the present study demonstrated that hydroxyapatite-hPRP could be an attractive alternative for reconstruction of the major diaphyseal defects of the long bones in animal models.

Differences in Bone Quality between High versus Low Turnover Renal Osteodystrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porter, Daniel S.; Pienkowski, David; Faugere, Marie-Claude

2012-01-01

Abnormal bone turnover is common in chronic kidney disease (CKD), but its effects on bone quality remain unclear. This study sought to quantify the relationship between abnormal bone turnover and bone quality. Iliac crest bone biopsies were obtained from CKD-5 patients on dialysis with low (n=18) or high (n=17) turnover, and from volunteers (n=12) with normal turnover and normal kidney function. Histomorphometric methods were used to quantify the microstructural parameters; Fourier transform infrared spectroscopy and nanoindentation were used to quantify the material and mechanical properties in bone. Reduced mineral-to-matrix ratio, mineral crystal size, stiffness and hardness were observed in bonemore » with high turnover compared to bone with normal or low turnover. Decreased cancellous bone volume and trabecular thickness were seen in bone with low turnover compared to bone with normal or high turnover. Bone quality, as defined by its microstructural, material, and mechanical properties, is related to bone turnover. These data suggest that turnover related alterations in bone quality may contribute to the known diminished mechanical competence of bone in CKD patients, albeit from different mechanisms for bone with high (material abnormality) vs. low (microstructural alteration) turnover. The present findings suggest that improved treatments for renal osteodystrophy should seek to avoid low or high bone turnover and aim for turnover rates as close to normal as possible.« less

Relationships among ultrasonic and mechanical properties of cancellous bone in human calcaneus in vitro.

PubMed

Wear, Keith A; Nagaraja, Srinidhi; Dreher, Maureen L; Sadoughi, Saghi; Zhu, Shan; Keaveny, Tony M

2017-10-01

Clinical bone sonometers applied at the calcaneus measure broadband ultrasound attenuation and speed of sound. However, the relation of ultrasound measurements to bone strength is not well-characterized. Addressing this issue, we assessed the extent to which ultrasonic measurements convey in vitro mechanical properties in 25 human calcaneal cancellous bone specimens (approximately 2×4×2cm). Normalized broadband ultrasound attenuation, speed of sound, and broadband ultrasound backscatter were measured with 500kHz transducers. To assess mechanical properties, non-linear finite element analysis, based on micro-computed tomography images (34-micron cubic voxel), was used to estimate apparent elastic modulus, overall specimen stiffness, and apparent yield stress, with models typically having approximately 25-30 million elements. We found that ultrasound parameters were correlated with mechanical properties with R=0.70-0.82 (p<0.001). Multiple regression analysis indicated that ultrasound measurements provide additional information regarding mechanical properties beyond that provided by bone quantity alone (p≤0.05). Adding ultrasound variables to linear regression models based on bone quantity improved adjusted squared correlation coefficients from 0.65 to 0.77 (stiffness), 0.76 to 0.81 (apparent modulus), and 0.67 to 0.73 (yield stress). These results indicate that ultrasound can provide complementary (to bone quantity) information regarding mechanical behavior of cancellous bone. Published by Elsevier Inc.

The electron microscope appearance of the subchondral bone plate in the human femoral head in osteoarthritis and osteoporosis

PubMed Central

LI, BAOHUA; MARSHALL, DEBORAH; ROE, MARTIN; ASPDEN, RICHARD M.

1999-01-01

The subchondral bone plate supports the articular cartilage in diarthrodial joints. It has a significant mechanical function in transmitting loads from the cartilage into the underlying cancellous bone and has been implicated in the destruction of cartilage in osteoarthritis (OA) and its sparing in osteoporosis (OP), but little is known of its composition, structure or material properties. This study investigated the microscopic appearance and mineral composition of the subchondral bone plate in femoral heads from patients with OA or OP to determine how these correspond to changes in composition and stiffness found in other studies. Freeze-fractured full-depth samples of the subchondral bone plate from the femoral heads of patients with osteoarthritis, osteoporosis or a matched control group were examined using back scattered and secondary emission scanning electron microscopy. Other samples were embedded and polished and examined using back-scattered electron microscopy and electron probe microanalysis. The appearances of the samples from the normal and osteoporotic patients were very similar, with the subchondral bone plate overlayed by a layer of calcified cartilage. Osteoporotic samples presented a more uniform fracture surface and the relative thicknesses of the layers appeared to be different. In contrast, the OA bone plate appeared to be porous and have a much more textured surface. There were occasional sites of microtrabecular bone formation between the trabeculae of the underlying cancellous bone, which were not seen in the other groups, and more numerous osteoclast resorption pits. The calcified cartilage layer was almost absent and the bone plate was apparently thickened. The appearance of the osteoarthritic subchondral bone plate was, therefore, considerably different from both the normal and the osteoporotic, strongly indicative of abnormal cellular activity. PMID:10473297

ATOMIC ENERGY COMMISSION PROGRESS REPORT ON BONE RESEARCH , 1960-1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1962-10-31

A review of osteoporosis concepts is presented. Activities in an experimental program to study osteoporosis by examining mineral metabolism in bone and by examining bone composition and density are reported. Sr/sup 85/ was administered to seven osteoporotic patients as a tracer for skeletal mineral metabolism. The activity levels in the blood and the excretion rate were measured. From these data the accretion rate and the diffusible component volume were calculated. It was found that the accretion rate was not increased in any case. The size of the diffusible component was normal in six patients and reduced in one. Concurrent experimentsmore » with estrogen administration were conducted. Over-all results indicate that in osteoporosis, the rate of bone accretion is never elevated and an effect of estrogen administration was the decrease of bone resorption rather than stimulation of bone formation. In studies of skeletal metabolism, the kinetics of Sr/sup 85/ metabolism was compared in normal subjects and patients with skeletal disorders. Various aspects of the results are analyzed and it is concluded that values obtained by kinetic studies appear to be quantitative, reproducible, and to correlate with presently established information on alterations of bone metabolism in systemic deseases. In studies of peripheral circulation and bone growth, I/sup 131tagged human serum albumin was injected in animals. The investigation was conducted to determine blood volumne turnover rate in extremities, to correlate changes in this rate with fractures and bone disorders, and to examine the method for use in evaluation of circulation under certain pathological conditions. Data and findings are included. Data are also included on in vitro mobilization of Sr/ sup 85/ during bone formation and bone density studies. (J.R.D.)« less

Peripheral blood biomarkers of solid tumor angiogenesis in dogs: A polychromatic flow cytometry pilot study

PubMed Central

Bentley, R. Timothy; Mund, Julie A.; Pollok, Karen E.; Childress, Michael O.; Case, Jamie

2012-01-01

A subset of peripheral blood hematopoietic stem and progenitor cells of bone marrow origin is elevated in humans with solid cancers before treatment and declines with therapy. This biomarker of angiogenesis is not specific to tumor type and has great potential in the objective assessment of treatment response in clinical trials. This pilot study was designed to develop a biomarker of neoangiogenesis in dogs for the diagnosis of cancer, the measurement of treatment response, and the provision of objective data in clinical trials. Polychromatic flow cytometry was used to quantify two subsets of circulating hematopoietic stem and progenitor cells in dogs with spontaneous solid tumors before (n = 8) and after (n = 3) treatment, and normal controls (n = 6). Pro-angiogenic peripheral blood cells of bone marrow origin were detected in all eight cases and the six normal controls; however, there was no statistically significant difference between the two groups. Interestingly, an apparent decline in pro-angiogenic cells was observed after treatment. Bone marrow derived hematopoietic cells appear to contribute to tumor angiogenesis in dogs, as has been previously reported in humans. While the methodology for pro-angiogenic cell quantification in a small number of dogs in the current study did not result in a significant difference from normal controls, an optimized canine polychromatic flow cytometry protocol holds great promise in the development of a canine cancer model and for the objective measurements of treatment response in clinical trials. PMID:23063489

Deletion of Mecom in mouse results in early-onset spinal deformity and osteopenia.

PubMed

Juneja, Subhash C; Vonica, Alin; Zeiss, Caroline; Lezon-Geyda, Kimberly; Yatsula, Bogdan; Sell, David R; Monnier, Vincent M; Lin, Sharon; Ardito, Thomas; Eyre, David; Reynolds, David; Yao, Zhenqiang; Awad, Hani A; Yu, Hongbo; Wilson, Michael; Honnons, Sylvie; Boyce, Brendan F; Xing, Lianping; Zhang, Yi; Perkins, Archibald S

2014-03-01

Recent studies have indicated a role for a MECOM allele in susceptibility to osteoporotic fractures in humans. We have generated a mutation in Mecom in mouse (termed ME(m1)) via lacZ knock-in into the upstream transcription start site for the gene, resulting in disruption of Mds1 and Mds1-Evi1 transcripts, but not of Evi1 transcripts. We demonstrate that ME(m1/m1) mice have severe kyphoscoliosis that is reminiscent of human congenital or primary kyphoscoliosis. ME(m1/m1) mice appear normal at birth, but by 2weeks, they exhibit a slight lumbar lordosis and narrowed intervertebral space. This progresses to severe lordosis with disc collapse and synostosis, together with kyphoscoliosis. Bone formation and strength testing show that ME(m1/m1) mice have normal bone formation and composition but are osteopenic. While endochondral bone development is normal, it is markedly dysplastic in its organization. Electron micrographs of the 1week postnatal intervertebral discs reveals marked disarray of collagen fibers, consistent with an inherent weakness in the non-osseous connective tissue associated with the spine. These findings indicate that lack of ME leads to a complex defect in both osseous and non-osseous musculoskeletal tissues, including a marked vertebral osteopenia, degeneration of the IVD, and disarray of connective tissues, which is likely due to an inherent inability to establish and/or maintain components of these tissues. Copyright © 2013 Elsevier Inc. All rights reserved.

Identification of a human erythroid progenitor cell population which expresses the CD34 antigen and binds the plant lectin Ulex europaeus I.

PubMed

Unverzagt, K L; Martinson, J; Lee, W; Stiff, P J; Williams, S; Bender, J G

1996-01-01

Two and three color flow cytometry of normal human bone marrow was used to identify CD34+ progenitor cells and examine their binding to the plant lectin Ulex europaeus I (Ulex). In normal bone marrow, 48.48 +/- 17.4% of the CD34+ cells bind to Ulex. Two color flow cytometry was used to sort CD34 + cells, and subsets of CD34+ cells, CD34+ Ulex+ and CD34+ Ulex-. These populations were sorted into colony assays to assess myeloid (CFU-GM) and erythroid (BFU-E) progenitors. The CD34+ Ulex+ subset was 84 +/- 14% BFU-E colonies (mean +/- S.D.) and had the highest cloning efficiency of 28 +/- 13%. Three color analysis of CD34+ Ulex+ cells showed staining with other erythroid (CD71, GlyA) antibodies and lack of stain. ing with myeloid (CD13, CD45RA) antibodies. These studies confirmed the erythroid characteristics of this subpopulation.

Mechanical signaling in the development of postmenopausal osteoporosis

NASA Technical Reports Server (NTRS)

Turner, R. T.

1999-01-01

Estrogen deficiency results in increased bone turnover and net bone loss in rats as well as humans. The respective roles of bone turnover and mechanical strain in mediating estrogen deficiency-induced cancellous bone loss were investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in long bones. However, cancellous bone was preferentially lost in the metaphysis, a site that experiences low strain energy during normal physical activity. No bone loss was observed in the epiphysis, a site experiencing higher strain energy, despite a similar increase in bone turnover. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased or decreased in long bones of ovariectomized rats by treadmill exercise or functional unloading, respectively. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing weight bearing accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in unloaded limbs and prevented bone loss in the loaded limbs. These results suggest that estrogen alters the mechanosensory (mechanostat) set point for skeletal adaptation, effectively reducing the minimum strain energy levels at which bone is added. Additionally, these studies suggest that physical activity as well as endocrine status play an important role in maintenance of the female skeleton during aging.

A novel mutation in the human aromatase gene: insights on the relationship among serum estradiol, longitudinal growth and bone mineral density in an adult man under estrogen replacement treatment.

PubMed

Lanfranco, Fabio; Zirilli, Lucia; Baldi, Matteo; Pignatti, Elisa; Corneli, Ginevra; Ghigo, Ezio; Aimaretti, Gianluca; Carani, Cesare; Rochira, Vincenzo

2008-09-01

Here we report on a new case of human aromatase deficiency in a man of 26 years of age and present the results of five year follow-up during trandermal estradiol (tE2) substitution, focusing on bone growth and mineralization. The lack of patient's compliance to tE2 treatment, resulting in low but detectable serum estradiol levels, provides helpful information about the physiological estradiol needed in serum to guarantee a complete bone maturation and mineralization. Clinical case report study. Genetic, biochemical and hormonal evaluations and the study of bone health were performed before and during estrogen treatment. Eunuchoid body proportions, unfused epiphyses, tall stature, osteopenia, increase fasting insulin, mild astenozoospermia and a history of right cryptorchidism were present. Baseline serum FSH was slightly above the normal range and estradiol was undetectable. Genetic analysis revealed a pattern of compound heterozygosity due to 23 bp deletion in exon IV and a point mutation in the first nucleotide of intron IX of the CYP19A1 gene, respectively. The closure of epiphyseal cartilage, the normalization of bone BMD and bone turnover markers, and the improvement of insulin levels were reached during tE2 only when serum estradiol raised above 73 pmol/L. Sperm parameters and overweight did not improve with substitutive therapy. This new case of aromatase deficiency underlines the role of estrogen on skeletal maturation, BMD, metabolic abnormalities and gonadal axis. It provides evidence on the need not only of a continuous estrogen replacement, but also of ensuring adequate estradiol levels in serum in order to ensure a complete bone maturation and mineralization and to prevent the worsening of body skeletal proportions. The comprehension of this physiological aspect has relevant clinical significance especially for the development of new therapeutic strategies useful to treat growth disorders by targeting serum estradiol in men.

Effects of Recombinant Human Growth Hormone for Osteoporosis: Systematic Review and Meta-Analysis.

PubMed

Atkinson, Hayden F; Moyer, Rebecca F; Yacoub, Daniel; Coughlin, Dexter; Birmingham, Trevor B

2017-03-01

Our objective was to evaluate the efficacy of recombinant human growth hormone (GH) on bone mineral density (BMD) in persons age 50 and older, with normal pituitary function, with or at risk for developing osteoporosis. We systematically reviewed randomized clinical trials (RCTs), searching six databases, and conducted meta-analyses to examine GH effects on BMD of the lumbar spine and femoral neck. Data for fracture incidence, bone metabolism biomarkers, and adverse events were also extracted and analysed. Thirteen RCTs met the eligibility criteria. Pooled effect sizes suggested no significant GH effect on BMD. Pooled effect sizes were largest, but nonsignificant, when compared to placebo. GH had a significant effect on several bone metabolism biomarkers. A significantly higher rate of adverse events was observed in the GH groups. Meta-analysis of RCTs suggests that GH treatment for persons with or at risk for developing osteoporosis results in very small, nonsignificant increases in BMD.

Fracture healing: mechanisms and interventions

PubMed Central

Einhorn, Thomas A.; Gerstenfeld, Louis C.

2015-01-01

Fractures are the most common large-organ, traumatic injuries to humans. The repair of bone fractures is a postnatal regenerative process that recapitulates many of the ontological events of embryonic skeletal development. Although fracture repair usually restores the damaged skeletal organ to its pre-injury cellular composition, structure and biomechanical function, about 10% of fractures will not heal normally. This article reviews the developmental progression of fracture healing at the tissue, cellular and molecular levels. Innate and adaptive immune processes are discussed as a component of the injury response, as are environmental factors, such as the extent of injury to the bone and surrounding tissue, fixation and the contribution of vascular tissues. We also present strategies for fracture treatment that have been tested in animal models and in clinical trials or case series. The biophysical and biological basis of the molecular actions of various therapeutic approaches, including recombinant human bone morphogenetic proteins and parathyroid hormone therapy, are also discussed. PMID:25266456

Biological Perspectives of Delayed Fracture Healing

PubMed Central

Hankenson, KD; Zmmerman, G; Marcucio, R

2015-01-01

Fracture healing is a complex biological process that requires interaction among a series of different cell types. Maintaining the appropriate temporal progression and spatial pattern is essential to achieve robust healing. We can temporally assess the biological phases via gene expression, protein analysis, histologically, or non-invasively using biomarkers as well as imaging techniques. However, determining what leads to normal verses abnormal healing is more challenging. Since the ultimate outcome of the process of fracture healing is to restore the original functions of bone, assessment of fracture healing should include not only monitoring the restoration of structure and mechanical function, but also an evaluation of the restoration of normal bone biology. Currently very few non-invasive measures of the biology of healing exist; however, recent studies that have correlated non-invasive measures with fracture healing outcome in humans have shown that serum TGFbeta1 levels appear to be an indicator of healing vs non-healing. In the future, developing additional serum measures to assess biological healing will improve the reliability and permit us to assess stages of fracture healing. Additionally, new functional imaging technologies could prove useful for better understanding both normal fracture healing and predicting dysfunctional healing in human patients. PMID:24857030

Successful human long-term application of in situ bone tissue engineering

PubMed Central

Horch, Raymund E; Beier, Justus P; Kneser, Ulrich; Arkudas, Andreas

2014-01-01

Tissue Engineering (TE) and Regenerative Medicine (RM) have gained much popularity because of the tremendous prospects for the care of patients with tissue and organ defects. To overcome the common problem of donor-site morbidity of standard autologous bone grafts, we successfully combined tissue engineering techniques for the first time with the arteriovenous loop model to generate vascularized large bone grafts. We present two cases of large bone defects after debridement of an osteomyelitis. One of the defects was localized in the radius and one in the tibia. For osseus reconstruction, arteriovenous loops were created as vascular axis, which were placed in the bony defects. In case 1, the bone generation was achieved using cancellous bone from the iliac crest and fibrin glue and in case 2 using a clinically approved β-tricalciumphosphate/hydroxyapatite (HA), fibrin glue and directly auto-transplanted bone marrow aspirate from the iliac crest. The following post-operative courses were uneventful. The final examinations took place after 36 and 72 months after the initial operations. Computer tomogrphy (CT), membrane resonance imaging (MRI) and doppler ultrasound revealed patent arterio-venous (AV) loops in the bone grafts as well as completely healed bone defects. The patients were pain-free with normal ranges of motion. This is the first study demonstrating successfully axially vascularized in situ tissue engineered bone generation in large bone defects in a clinical scenario using the arteriovenous loop model without creation of a significant donor-site defect utilizing TE and RM techniques in human patients with long-term stability. PMID:24801710

Transduction of Oct6 or Oct9 gene concomitant with Myc family gene induced osteoblast-like phenotypic conversion in normal human fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizoshiri, N.; Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto; Kishida, T.

Introduction: Osteoblasts play essential roles in bone formation and regeneration, while they have low proliferation potential. Recently we established a procedure to directly convert human fibroblasts into osteoblasts (dOBs). Transduction of Runx2 (R), Osterix (X), Oct3/4 (O) and L-myc (L) genes followed by culturing under osteogenic conditions induced normal human fibroblasts to express osteoblast-specific genes and produce calcified bone matrix both in vitro and in vivo Intriguingly, a combination of only two factors, Oct3/4 and L-myc, significantly induced osteoblast-like phenotype in fibroblasts, but the mechanisms underlying the direct conversion remains to be unveiled. Materials and Methods: We examined which Oct family genesmore » and Myc family genes are capable of inducing osteoblast-like phenotypic conversion. Results: As result Oct3/4, Oct6 and Oct9, among other Oct family members, had the capability, while N-myc was the most effective Myc family gene. The Oct9 plus N-myc was the best combination to induce direct conversion of human fibroblasts into osteoblast-like cells. Discussion: The present findings may greatly contribute to the elucidation of the roles of the Oct and Myc proteins in osteoblast direct reprogramming. The results may also lead to establishment of novel regenerative therapy for various bone resorption diseases. - Highlights: • Introducing L-myc in a combination with either Oct3/4, Oct6 or Oct9 enables the conversion of fibroblasts to osteoblasts. • A combination of L-myc with Oct3/4 or Oct9 can induce the cells to a phenotype closer to normal osteoblasts. • N-myc was considered the most appropriate Myc family gene for induction of osteoblast-like phenotype in fibroblasts. • The combination of Oct9 plus N-myc has the strongest capability of inducing osteoblast-like phenotype.« less

A Comprehensive Overview of Skeletal Phenotypes Associated with Alterations in Wnt/β-catenin Signaling in Humans and Mice

PubMed Central

Maupin, Kevin A.; Droscha, Casey J.; Williams, Bart O.

2013-01-01

The Wnt signaling pathway plays key roles in differentiation and development and alterations in this signaling pathway are causally associated with numerous human diseases. While several laboratories were examining roles for Wnt signaling in skeletal development during the 1990s, interest in the pathway rose exponentially when three key papers were published in 2001–2002. One report found that loss of the Wnt co-receptor, Low-density lipoprotein related protein-5 (LRP5), was the underlying genetic cause of the syndrome Osteoporosis pseudoglioma (OPPG). OPPG is characterized by early-onset osteoporosis causing increased susceptibility to debilitating fractures. Shortly thereafter, two groups reported that individuals carrying a specific point mutation in LRP5 (G171V) develop high-bone mass. Subsequent to this, the causative mechanisms for these observations heightened the need to understand the mechanisms by which Wnt signaling controlled bone development and homeostasis and encouraged significant investment from biotechnology and pharmaceutical companies to develop methods to activate Wnt signaling to increase bone mass to treat osteoporosis and other bone disease. In this review, we will briefly summarize the cellular mechanisms underlying Wnt signaling and discuss the observations related to OPPG and the high-bone mass disorders that heightened the appreciation of the role of Wnt signaling in normal bone development and homeostasis. We will then present a comprehensive overview of the core components of the pathway with an emphasis on the phenotypes associated with mice carrying genetically engineered mutations in these genes and clinical observations that further link alterations in the pathway to changes in human bone. PMID:26273492

Estrogen regulates the rate of bone turnover but bone balance in ovariectomized rats is modulated by prevailing mechanical strain

NASA Technical Reports Server (NTRS)

Westerlind, K. C.; Wronski, T. J.; Ritman, E. L.; Luo, Z. P.; An, K. N.; Bell, N. H.; Turner, R. T.

1997-01-01

Estrogen deficiency induced bone loss is associated with increased bone turnover in rats and humans. The respective roles of increased bone turnover and altered balance between bone formation and bone resorption in mediating estrogen deficiency-induced cancellous bone loss was investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in the distal femur. However, cancellous bone was preferentially lost in the metaphysis, a site that normally experiences low strain energy. No bone loss was observed in the epiphysis, a site experiencing higher strain energy. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased and decreased in long bones of ovariectomized rats by treadmill exercise and functional unloading, respectively. Functional unloading was achieved during orbital spaceflight and following unilateral sciatic neurotomy. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing loading accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in the unloaded and prevented loss in the loaded limb following unilateral sciatic neurotomy in part by reducing indices of bone turnover. These results suggest that estrogen regulates the rate of bone turnover, but the overall balance between bone formation and bone resorption is influenced by prevailing levels of mechanical strain.

Normal development and growth of the human neurocranium and cranial base.

PubMed

Friede, H

1981-01-01

The literature on normal development and growth of certain areas of the human head is reviewed, starting with the early induction of the desmal neurocranium. the development of the brain capsule with its dural reinforcement bands and their connection with the basicranium is discussed, as is the primordial chondrocranium, including its bone replacement. Growth of the calvaria and the three cranial fossae is also analysed. Special interest is focused on the anterior fossa, as knowledge of the growth in this area is very important for an understanding of pathogenesis and possibilities of treating premature craniosynostosis. Finally it is stressed that close observation of the effects of treatment on this pathology may increase our knowledge of normal growth.

Active Sonic Hedgehog Signaling between Androgen Independent Human Prostate Cancer Cells and Normal/Benign but Not Cancer-Associated Prostate Stromal Cells

PubMed Central

Shigemura, Katsumi; Huang, Wen-Chin; Li, Xiangyan; Zhau, Haiyen E.; Zhu, Guodong; Gotoh, Akinobu; Fujisawa, Masato; Xie, Jingwu; Marshall, Fray F.; Chung, Leland W. K.

2012-01-01

BACKGROUND Sonic hedgehog (Shh) signaling plays a pivotal role in stromal-epithelial interaction during normal development but its role in tumor-stromal interaction during carcinogenic progression is less well defined. Since hormone refractory prostate cancer with bone metastasis is difficult to treat, it is crucial to investigate how androgen independent (AI) human prostate cancer cells communicate with their associated stroma. METHODS Shh and its target transcription factor, Gli1 mRNA, were assessed by RT-PCR and/or quantitative RT-PCR in co-cultured cell recombinants comprised of AI C4-2 either with NPF (prostate fibroblasts from normal/benign prostate gland) or CPF cancer-associated stromal fibroblasts) under Shh/cyclopamine (a hedgehog signaling inhibitor) treatment. Human bone marrow stromal (HS27A) cells were used as controls. In vivo investigation was performed by checking serum PSA and immunohistochemical staining for the apoptosis-associated M30 gene in mice bearing chimeric C4-2/NPF tumors. RESULTS CONCLUSIONS Based on co-culture and chimeric tumor models, active Shh-mediated signaling was demonstrated between AI prostate cancer and NPF in a paracrine- and tumor progression-dependent manner. Our study suggests that drugs like cyclopamine that interfere with Shh signaling could be beneficial in preventing AI progression in prostate cancer cells. PMID:21520153

Experimental Analysis of the Mechanism of Hearing under Water

PubMed Central

Chordekar, Shai; Kishon-Rabin, Liat; Kriksunov, Leonid; Adelman, Cahtia; Sohmer, Haim

2015-01-01

The mechanism of human hearing under water is debated. Some suggest it is by air conduction (AC), others by bone conduction (BC), and others by a combination of AC and BC. A clinical bone vibrator applied to soft tissue sites on the head, neck, and thorax also elicits hearing by a mechanism called soft tissue conduction (STC) or nonosseous BC. The present study was designed to test whether underwater hearing at low intensities is by AC or by osseous BC based on bone vibrations or by nonosseous BC (STC). Thresholds of normal hearing participants to bone vibrator stimulation with their forehead in air were recorded and again when forehead and bone vibrator were under water. A vibrometer detected vibrations of a dry human skull in all similar conditions (in air and under water) but not when water was the intermediary between the sound source and the skull forehead. Therefore, the intensities required to induce vibrations of the dry skull in water were significantly higher than the underwater hearing thresholds of the participants, under conditions when hearing by AC and osseous BC is not likely. The results support the hypothesis that hearing under water at low sound intensities may be attributed to nonosseous BC (STC). PMID:26770975

Edentulation alters material properties of cortical bone in the human craniofacial skeleton: functional implications for craniofacial structure in primate evolution

PubMed Central

Dechow, Paul C.; Wang, Qian; Peterson, Jill

2011-01-01

Skeletal adaptations to reduced function are an important source of skeletal variation and may be indicative of environmental pressures that lead to evolutionary changes. Humans serve as a model animal to investigate the effects of loss of craniofacial function through edentulation. In the human maxilla, it is known that edentulation leads to significant changes in skeletal structure such as residual ridge resorption and loss of cortical thickness. However, little is known about changes in bone tissue structure and material properties, which are also important for understanding skeletal mechanics but are often ignored. The aims of this study were to determine cortical material properties in edentulous crania and to evaluate differences with dentate crania and thus examine the effects of loss of function on craniofacial structure. Cortical bone samples from fifteen edentulous human skulls were measured for thickness and density. Elastic properties and directions of maximum stiffness were determined by using ultrasonic techniques. These data were compared to those from dentate crania reported in a previous investigation. Cortical bone from all regions of the facial skeleton of edentulous individuals is thinner than in dentate skulls. Elastic and shear moduli, and density are similar or greater in the zygoma and cranial vault of edentulous individuals, while these properties are less in the maxilla. Most cortical bone, especially in edentulous maxillae, has reduced directional orientation. The loss of significant occlusal loads following edentulation may contribute to the change in material properties and the loss of orientation over time during the normal process of bone remodeling. These results suggest that area-specific cortical microstructural changes accompany bone resorption following edentulation. They also suggest that functional forces are important for maintaining bone mass throughout the craniofacial skeleton, even in areas such as the browridges, which have been thought to be little affected by function, because of low in vivo strains found there in several primate studies. PMID:20235319

MicroRNA profiling reveals dysregulated microRNAs and their target gene regulatory networks in cemento-ossifying fibroma.

PubMed

Pereira, Thaís Dos Santos Fontes; Brito, João Artur Ricieri; Guimarães, André Luiz Sena; Gomes, Carolina Cavaliéri; de Lacerda, Júlio Cesar Tanos; de Castro, Wagner Henriques; Coimbra, Roney Santos; Diniz, Marina Gonçalves; Gomez, Ricardo Santiago

2018-01-01

Cemento-ossifying fibroma (COF) is a benign fibro-osseous neoplasm of uncertain pathogenesis, and its treatment results in morbidity. MicroRNAs (miRNA) are small non-coding RNAs that regulate gene expression and may represent therapeutic targets. The purpose of the study was to generate a comprehensive miRNA profile of COF compared to normal bone. Additionally, the most relevant pathways and target genes of differentially expressed miRNA were investigated by in silico analysis. Nine COF and ten normal bone samples were included in the study. miRNA profiling was carried out by using TaqMan® OpenArray® Human microRNA panel containing 754 validated human miRNAs. We identified the most relevant miRNAs target genes through the leader gene approach, using STRING and Cytoscape software. Pathways enrichment analysis was performed using DIANA-miRPath. Eleven miRNAs were downregulated (hsa-miR-95-3p, hsa-miR-141-3p, hsa-miR-205-5p, hsa-miR-223-3p, hsa-miR-31-5p, hsa-miR-944, hsa-miR-200b-3p, hsa-miR-135b-5p, hsa-miR-31-3p, hsa-miR-223-5p and hsa-miR-200c-3p), and five were upregulated (hsa-miR-181a-5p, hsa-miR-181c-5p, hsa-miR-149-5p, hsa-miR-138-5p and hsa-miR-199a-3p) in COF compared to normal bone. Eighteen common target genes were predicted, and the leader genes approach identified the following genes involved in human COF: EZH2, XIAP, MET and TGFBR1. According to the biology of bone and COF, the most relevant KEGG pathways revealed by enrichment analysis were proteoglycans in cancer, miRNAs in cancer, pathways in cancer, p53-, PI3K-Akt-, FoxO- and TGF-beta signalling pathways, which were previously found to be differentially regulated in bone neoplasms, odontogenic tumours and osteogenesis. miRNA dysregulation occurs in COF, and EZH2, XIAP, MET and TGFBR1 are potential targets for functional analysis validation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of type 2 diabetes-related non-enzymatic glycation on bone biomechanical properties

PubMed Central

Karim, Lamya; Bouxsein, Mary L.

2015-01-01

There is clear evidence that patients with type 2 diabetes mellitus (T2D) have increased fracture risk, despite having high bone mineral density (BMD) and body mass index (BMI). Thus, poor bone quality has been implicated as a mechanism contributing to diabetic skeletal fragility. Poor bone quality in T2D may result from the accumulation of advanced glycation end-products (AGEs), which are post-translational modifications of collagen resulting from a spontaneous reaction between extracellular sugars and amino acid residues on collagen fibers. This review discusses what is known and what is not known regarding AGE accumulation and diabetic skeletal fragility, examining evidence from in vitro experiments to simulate a diabetic state, ex vivo studies in normal and diabetic human bone, and diabetic animal models. Key findings in the literature are that AGEs increase with age, affect bone cell behavior, and are altered with changes in bone turnover. Further, they affect bone mechanical properties and microdamage accumulation, and can be inhibited in vitro by various inhibitors and breakers (e.g. aminoguanidine, N-Phenacylthiazolium Bromide, vitamin B6). While a few studies report higher AGEs in diabetic animal models, there is little evidence of AGE accumulation in bone from diabetic patients. There are several limitations and inconsistencies in the literature that should be noted and studied in greater depth including understanding the discrepancies between glycation levels across reported studies, clarifying differences in AGEs in cortical versus cancellous bone, and improving the very limited data available regarding glycation content in diabetic animal and human bone, and its corresponding effect on bone material properties in T2D. PMID:26211993

Bone formation at recombinant human bone morphogenetic protein-2-coated titanium implants in the posterior mandible (Type II bone) in dogs.

PubMed

Wikesjö, Ulf M E; Xiropaidis, Andreas V; Qahash, Mohammed; Lim, Won Hee; Sorensen, Rachel G; Rohrer, Michael D; Wozney, John M; Hall, Jan

2008-11-01

Conventional oral/maxillofacial implants reach osseointegration over several months during which the titanium fixtures interact with alveolar bone. The objective of this study was to determine if adsorbing recombinant human bone morphogenetic protein-2 (rhBMP-2) onto a titanium porous oxide (TPO) implant surface might enhance or accelerate local bone formation and support osseointegration in a large animal oral/maxillofacial orthotopic model. Endosseous implants with a TPO surface were installed into the edentulated posterior mandible in eight adult Hound Labrador mongrel dogs. The implant surface had been adsorbed with rhBMP-2 at 0.2 or 4.0 mg/ml. TPO implants without rhBMP-2 served as control. Treatments were randomized between jaw quadrants. Mucosal flaps were advanced and sutured leaving the implants submerged. Clinical and radiographic evaluations were made immediately post-surgery, at day 10 (suture removal), and week 4 and 8 post-surgery. The animals received fluorescent bone markers at week 3, 4, and at week 8 post-surgery, when they were euthanized for histologic analysis. TPO implants coated with rhBMP-2 exhibited dose-dependent bone remodelling including immediate resorption and formation of implant adjacent bone, and early establishment of clinically relevant osseointegration. The resulting bone-implant contact, although clinically respectable, appeared significantly lower for rhBMP-2-coated implants compared with the control [rhBMP-2 (0.2 mg/ml) 43.3+/-10.8%versus 71.7+/-7.8%, p<0.02; rhBMP-2 (4.0 mg/ml) 35.4+/-10.6%versus 68.2+/-11.0%, p<0.03]. rhBMP-2 adsorbed onto TPO implant surfaces initiates dose-dependent peri-implant bone re-modelling resulting in the formation of normal, physiologic bone and clinically relevant osseointegration within 8 weeks.

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

PubMed

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 < 0.01) suggesting a more severe bone phenotype than JAK2(V617F). Decreased osteoblast numbers and bone formation along with normal osteoclast numbers and activity were found in both mice. This study indicates that PV is associated with low bone mass and decreased osteoblast activity in mice. Our results support future studies of osteoporosis in affected humans. Polycythemia caused by chronically elevated circulating EPO also results in bone loss, and implications on patients treated with rEPO should be evaluated.

Normal hematopoiesis and lack of β-catenin activation in osteoblasts of patients and mice harboring Lrp5 gain-of-function mutations.

PubMed

Galán-Díez, Marta; Isa, Adiba; Ponzetti, Marco; Nielsen, Morten Frost; Kassem, Moustapha; Kousteni, Stavroula

2016-03-01

Osteoblasts are emerging regulators of myeloid malignancies since genetic alterations in them, such as constitutive activation of β-catenin, instigate their appearance. The LDL receptor-related protein 5 (LRP5), initially proposed to be a co-receptor for Wnt proteins, in fact favors bone formation by suppressing gut-serotonin synthesis. This function of Lrp5 occurring in the gut is independent of β-catenin activation in osteoblasts. However, it is unknown whether Lrp5 can act directly in osteoblast to influence other functions that require β-catenin signaling, particularly, the deregulation of hematopoiesis and leukemogenic properties of β-catenin activation in osteoblasts, that lead to development of acute myeloid leukemia (AML). Using mice with gain-of-function (GOF) Lrp5 alleles (Lrp5(A214V)) that recapitulate the human high bone mass (HBM) phenotype, as well as patients with the T253I HBM Lrp5 mutation, we show here that Lrp5 GOF mutations in both humans and mice do not activate β-catenin signaling in osteoblasts. Consistent with a lack of β-catenin activation in their osteoblasts, Lrp5(A214V) mice have normal trilinear hematopoiesis. In contrast to leukemic mice with constitutive activation of β-catenin in osteoblasts (Ctnnb1(CAosb)), accumulation of early myeloid progenitors, a characteristic of AML, myeloid-blasts in blood, and segmented neutrophils or dysplastic megakaryocytes in the bone marrow, are not observed in Lrp5(A214V) mice. Likewise, peripheral blood count analysis in HBM patients showed normal hematopoiesis, normal percentage of myeloid cells, and lack of anemia. We conclude that Lrp5 GOF mutations do not activate β-catenin signaling in osteoblasts. As a result, myeloid lineage differentiation is normal in HBM patients and mice. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance edited by Peter Ruvolo and Gregg L. Semenza. Published by Elsevier B.V.

Purification and characterization of a tripeptidyl peptidase I from human osteoclastomas: evidence for its role in bone resorption.

PubMed

Page, A E; Fuller, K; Chambers, T J; Warburton, M J

1993-11-01

Tripeptidyl peptidase I (EC 3.4.14.9), which cleaves tripeptides from the N-terminus of synthetic substrates, has been purified from human osteoclastomas (a bone tumor containing large numbers of normal osteoclasts). The enzyme has an M(r) of 48 kDa but forms aggregates with an M(r) of about 700 kDa. The tripeptidyl peptidase has an acidic pH optimum (approximately pH 5.0), suggesting that it has a lysosomal localization and prefers substrates with a hydrophobic amino acid in the P1 position. There is an absolute requirement for a nonsubstituted N-terminus. The enzyme is inhibited by reagents which modify serine and histidine residues. Lysosomal tripeptidyl peptidase is known to be capable of cleaving Gly-Pro-X triplets from synthetic collagen-like polypeptides. Ala-Ala-Phe-CH2Cl, a potent inhibitor of osteoclastoma tripeptidyl peptidase, inhibits osteoclastic bone resorption in an in vitro test system. This suggests that tripeptidyl peptidase I, secreted by osteoclasts, is involved at some stage in the degradation of bone collagen.

An in vitro study of fibrin sealant as a carrier system for recombinant human bone morphogenetic protein (rhBMP)-9 for bone tissue engineering.

PubMed

Fujioka-Kobayashi, Masako; Mottini, Matthias; Kobayashi, Eizaburo; Zhang, Yufeng; Schaller, Benoit; Miron, Richard J

2017-01-01

In the craniofacial bone field, fibrin sealants are used as coagulant and adhesive tools to stabilize grafts during surgery. Despite this, their exact role in osteogenesis is poorly characterized. In the present study, we aimed to characterize the osteogenic potential of TISSEEL fibrin sealant and used its technology to incorporate growth factors within its matrix. We focused on recombinant human bone morphogenetic protein (rhBMP)-9, which has previously been characterized as one of the strongest osteogenetic inducers in the BMP family. TISSEEL displayed an excellent ability to retain rhBMP9, which was gradually released over a 10-day period. Although TISSEEL decreased bone stromal ST2 cell attachment at 8 h, it displayed normal cell proliferation at 1, 3, and 5 days when compared to tissue culture plastic. Interestingly, TISSEEL had little influence on osteoblast differentiation; however its combination with rhBMP9 significantly increased ALP activity at 7 days, Alizarin Red staining at 14 days, and mRNA levels of osteoblast differentiation markers ALP, bone sialoprotein, and osteocalcin. In summary, although fibrin sealants were shown to have little influence on osteogenesis, their combination with bone-inducing growth factors such as rhBMP9 may serve as an attractive carrier/scaffold for future bone regenerative strategies. Future animal studies are now necessary. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Synthetic osteogenic extracellular matrix formed by coated silicon dioxide nanosprings

PubMed Central

2012-01-01

Background The design of biomimetic materials that parallel the morphology and biology of extracellular matrixes is key to the ability to grow functional tissues in vitro and to enhance the integration of biomaterial implants into existing tissues in vivo. Special attention has been put into mimicking the nanostructures of the extracellular matrix of bone, as there is a need to find biomaterials that can enhance the bonding between orthopedic devices and this tissue. Methods We have tested the ability of normal human osteoblasts to propagate and differentiate on silicon dioxide nanosprings, which can be easily grown on practically any surface. In addition, we tested different metals and metal alloys as coats for the nanosprings in tissue culture experiments with bone cells. Results Normal human osteoblasts grown on coated nanosprings exhibited an enhanced rate of propagation, differentiation into bone forming cells and mineralization. While osteoblasts did not attach effectively to bare nanowires grown on glass, these cells propagated successfully on nanosprings coated with titanium oxide and gold. We observed a 270 fold increase in the division rate of osteoblasts when grow on titanium/gold coated nanosprings. This effect was shown to be dependent on the nanosprings, as the coating by themselves did not alter the growth rate of osteoblast. We also observed that titanium/zinc/gold coated nanosprings increased the levels of osteoblast production of alkaline phosphatase seven folds. This result indicates that osteoblasts grown on this metal alloy coated nanosprings are differentiating to mature bone making cells. Consistent with this hypothesis, we showed that osteoblasts grown on the same metal alloy coated nanosprings have an enhanced ability to deposit calcium salt. Conclusion We have established that metal/metal alloy coated silicon dioxide nanosprings can be used as a biomimetic material paralleling the morphology and biology of osteogenic extracellular matrix. The coated nanosprings enhance normal human osteoblasts cellular behaviors needed for improving osseointegration of orthopedic materials. Thus, metal-coated nanosprings represent a novel biomaterial that could be exploited for improving success rates of orthopedic implant procedures. PMID:22284364

A "Bony" Proposition: Pathways Mediating Responses to Simulated Weightlessness and Radiation

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Globus, Ruth

2016-01-01

There is evidence that weightlessness and radiation, two elements of the spaceflight environment, can lead to detrimental changes in human musculoskeletal tissue, including bone loss and muscle atrophy. This bone loss is thought to be brought about by the increased activity of bone-resorbing osteoclasts and functional changes in bone-forming osteoblasts, cells that give rise to mature osteocytes. My current area of research focuses on understanding the mechanistic basis for the responses of bone to the spaceflight environment using earth-based animal and cellular models. The overarching goal is to identify molecular targets to prevent bone loss in space exploration and earth-based scenarios of radiotherapy, accidental radiation exposure and reduced mobility. In this talk, I will highlight two signaling pathways that potentially play a role in the response of bone to spaceflight-like conditions. Firstly, I will discuss the role of insulin-like growth factor 1 (IGF1) signaling as it pertains to the recovery of bone from simulated weightlessness (rodent hindlimb unloading model). Secondly, I will share recent findings from our study that aims to understand the emerging role of autophagy in maintaining the balance between bone formation and resorption (bone homeostasis) as well as normal skeletal structure.

Developmental abnormalities of the occipital bone in human chondrodystrophies (achondroplasia and thanatophoric dwarfism).

PubMed

Marin-Padilla, M; Marin-Padilla, T M

1977-01-01

Specific developmental malformations have been demonstrated in the occipital bone of two chondrodysplastic disorders (achondroplasia and thanatophoric dwarfism). Analysis of these malformations indicates that the occipital bone is primary affected in these disorders. In both cases, the endochondral-derived components of the occipital bone (the basioccipital, the two lateral parts, and the planum nuchale of the squama occipitalis) have failed to grow properly and are smaller and shorter than normal. On the other hand, the planum occipitalis of the squama, which derives from intramembranous ossification, is unaffected. In addition, the nature of these abnormalities indicates that the occipital synchondroses, together with the epiphyseal plates of other bones, are primarily affected in these two chondrodysplasias. The components of the occipital bone formed between the affected synchondroses failed to grow normally. The resulting malformation of the occipital bone is undoubtedly the cause of the shortening of the posterior cerebral fossa and of the considerable narrowing of the foramen magnum often described in these chondrodysplasias. It is postulated that growth disturbances between the affected occipital bone and the unaffected central nervous system results in the inadequacy of the posterior cerebral fossa and the foramen magnum to accommodate the growing brain. Consequently, compression of the brain at the posterior cerebral fossa or the foramen magnum levels could occur and thus lead to neurologic complications such as hydrocephalus and compression of the brain stem. It is suggested that the surgical removal of the fused posterior border of the lateral parts of the occipital bone (partial nuchalectomy) for the purpose of enlarging the narrow foramen magnum may be indicated in those chondrodysplastic children who develop these types of neurologic complications.

Physical Properties Of Acupuncture Needles: Do Disposable Acupuncture Needles Break With Normal Use

DTIC Science & Technology

2016-06-01

Lamb shank, which has complexity of tendon, fascia, and bone, was used to mimic human tissue. The needles (n=10) were stressed in the tissue substitute...needles were re-imaged after stressing and visually assessed. RESULTS: Only one manufacturing scuff mark was noted out of 90 needles before stress ...testing. Needles buckled but did not break when they were stressed beyond normal clinical use. No cracks or fractures were noted after stress

Ontogeny of the Human Pelvis.

PubMed

Verbruggen, Stefaan W; Nowlan, Niamh C

2017-04-01

The human pelvis has evolved over time into a remarkable structure, optimised into an intricate architecture that transfers the entire load of the upper body into the lower limbs, while also facilitating bipedal movement. The pelvic girdle is composed of two hip bones, os coxae, themselves each formed from the gradual fusion of the ischium, ilium and pubis bones. Unlike the development of the classical long bones, a complex timeline of events must occur in order for the pelvis to arise from the embryonic limb buds. An initial blastemal structure forms from the mesenchyme, with chondrification of this mass leading to the first recognisable elements of the pelvis. Primary ossification centres initiate in utero, followed post-natally by secondary ossification at a range of locations, with these processes not complete until adulthood. This cascade of events can vary between individuals, with recent evidence suggesting that fetal activity can affect the normal development of the pelvis. This review surveys the current literature on the ontogeny of the human pelvis. Anat Rec, 300:643-652, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

NELL-1 in the treatment of osteoporotic bone loss

DOE PAGES

James, Aaron W.; Shen, Jia; Zhang, Xinli; ...

2015-06-17

NELL-1 is a secreted, osteoinductive protein whose expression rheostatically controls skeletal ossification. Overexpression of NELL-1 results in craniosynostosis in humans and mice, whereas lack of Nell-1 expression is associated with skeletal undermineralization. Here we show that Nell-1-haploinsufficient mice have normal skeletal development but undergo age-related osteoporosis, characterized by a reduction in osteoblast: osteoclast (OB:OC) ratio and increased bone fragility. Recombinant NELL-1 binds to integrin β1 and consequently induces Wnt/β-catenin signalling, associated with increased OB differentiation and inhibition of OC-directed bone resorption. Systemic delivery of NELL-1 to mice with gonadectomy-induced osteoporosis results in improved bone mineral density. When extended to amore » large animal model, local delivery of NELL-1 to osteoporotic sheep spine leads to significant increase in bone formation. Furthermore, these findings suggest that NELL-1 deficiency plays a role in osteoporosis and demonstrate the potential utility of NELL-1 as a combination anabolic/antiosteoclastic therapeutic for bone loss.« less

NELL-1 in the treatment of osteoporotic bone loss

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, Aaron W.; Shen, Jia; Zhang, Xinli

NELL-1 is a secreted, osteoinductive protein whose expression rheostatically controls skeletal ossification. Overexpression of NELL-1 results in craniosynostosis in humans and mice, whereas lack of Nell-1 expression is associated with skeletal undermineralization. Here we show that Nell-1-haploinsufficient mice have normal skeletal development but undergo age-related osteoporosis, characterized by a reduction in osteoblast: osteoclast (OB:OC) ratio and increased bone fragility. Recombinant NELL-1 binds to integrin β1 and consequently induces Wnt/β-catenin signalling, associated with increased OB differentiation and inhibition of OC-directed bone resorption. Systemic delivery of NELL-1 to mice with gonadectomy-induced osteoporosis results in improved bone mineral density. When extended to amore » large animal model, local delivery of NELL-1 to osteoporotic sheep spine leads to significant increase in bone formation. Furthermore, these findings suggest that NELL-1 deficiency plays a role in osteoporosis and demonstrate the potential utility of NELL-1 as a combination anabolic/antiosteoclastic therapeutic for bone loss.« less

Successful human long-term application of in situ bone tissue engineering.

PubMed

Horch, Raymund E; Beier, Justus P; Kneser, Ulrich; Arkudas, Andreas

2014-07-01

Tissue Engineering (TE) and Regenerative Medicine (RM) have gained much popularity because of the tremendous prospects for the care of patients with tissue and organ defects. To overcome the common problem of donor-site morbidity of standard autologous bone grafts, we successfully combined tissue engineering techniques for the first time with the arteriovenous loop model to generate vascularized large bone grafts. We present two cases of large bone defects after debridement of an osteomyelitis. One of the defects was localized in the radius and one in the tibia. For osseus reconstruction, arteriovenous loops were created as vascular axis, which were placed in the bony defects. In case 1, the bone generation was achieved using cancellous bone from the iliac crest and fibrin glue and in case 2 using a clinically approved β-tricalciumphosphate/hydroxyapatite (HA), fibrin glue and directly auto-transplanted bone marrow aspirate from the iliac crest. The following post-operative courses were uneventful. The final examinations took place after 36 and 72 months after the initial operations. Computer tomogrphy (CT), membrane resonance imaging (MRI) and doppler ultrasound revealed patent arterio-venous (AV) loops in the bone grafts as well as completely healed bone defects. The patients were pain-free with normal ranges of motion. This is the first study demonstrating successfully axially vascularized in situ tissue engineered bone generation in large bone defects in a clinical scenario using the arteriovenous loop model without creation of a significant donor-site defect utilizing TE and RM techniques in human patients with long-term stability. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Severe hypocalcemia following bisphosphonate treatment in a patient with Paget's disease of bone.

PubMed

Whitson, Heather E; Lobaugh, Bruce; Lyles, Kenneth W

2006-10-01

Bisphosphonate therapy is a common and effective treatment for Paget's disease of bone, osteoporosis, hypercalcemia of malignancy and cancer metastatic to bone. Clinically significant hypocalcemia has not been reported in patients with Paget's disease of bone and normal parathyroid function treated with an aminobisphosphonate. We treated a 52-year-old woman with polyostotic Paget's disease of bone (serum alkaline phosphatase level-1971 IU/L [normal 31-110 IU/L]), who had not previously received bisphosphonates, with daily oral 30 mg risedronate, oral 1000 mg elemental calcium and oral 400 IU cholecalciferol. After 10 days of treatment, she developed severe hypocalcemia (5.4 mg/dL [normal 8.7-10.2 mg/dL]), requiring hospitalization and support with 5 days of intravenous calcium gluconate. On the day risedronate treatment began, her PTH was low normal at 14 pg/mL (normal 12-72 pg/mL), consistent with a relatively suppressed PTH axis due to high bone turnover. Her vitamin D level was within normal limits (serum 25(OH)D 19 ng/mL [normal 8-38 ng/mL]), although possibly not optimally repleted. We hypothesize that this case represents an example of hungry bone syndrome in a patient with extensive Paget's disease of bone who received risedronate, causing acute suppression of bone resorption while elevated bone formation rates continued. In the year following her recovery, the patient was successfully treated with slowly titrated anti-resorptive therapy (subcutaneous calcitonin followed by titrated doses of risedronate), and is now clinically well. Physicians should be aware of the potential for hypocalcemia when patients with polyostotic Paget's disease and markedly elevated indicators of bone remodeling are initiated on powerful anti-resorptive therapy.

High fat diet promotes achievement of peak bone mass in young rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna

Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fatmore » mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.« less

Chitosan-poly(lactide-co-glycolide) microsphere-based scaffolds for bone tissue engineering: in vitro degradation and in vivo bone regeneration studies.

PubMed

Jiang, Tao; Nukavarapu, Syam P; Deng, Meng; Jabbarzadeh, Ehsan; Kofron, Michelle D; Doty, Stephen B; Abdel-Fattah, Wafa I; Laurencin, Cato T

2010-09-01

Natural polymer chitosan and synthetic polymer poly(lactide-co-glycolide) (PLAGA) have been investigated for a variety of tissue engineering applications. We have previously reported the fabrication and in vitro evaluation of a novel chitosan/PLAGA sintered microsphere scaffold for load-bearing bone tissue engineering applications. In this study, the in vitro degradation characteristics of the chitosan/PLAGA scaffold and the in vivo bone formation capacity of the chitosan/PLAGA-based scaffolds in a rabbit ulnar critical-sized-defect model were investigated. The chitosan/PLAGA scaffold showed slower degradation than the PLAGA scaffold in vitro. Although chitosan/PLAGA scaffold showed a gradual decrease in compressive properties during the 12-week degradation period, the compressive strength and compressive modulus remained in the range of human trabecular bone. Chitosan/PLAGA-based scaffolds were able to guide bone formation in a rabbit ulnar critical-sized-defect model. Microcomputed tomography analysis demonstrated that successful bridging of the critical-sized defect on the sides both adjacent to and away from the radius occurred using chitosan/PLAGA-based scaffolds. Immobilization of heparin and recombinant human bone morphogenetic protein-2 on the chitosan/PLAGA scaffold surface promoted early bone formation as evidenced by complete bridging of the defect along the radius and significantly enhanced mechanical properties when compared to the chitosan/PLAGA scaffold. Furthermore, histological analysis suggested that chitosan/PLAGA-based scaffolds supported normal bone formation via intramembranous formation. 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

STK-1, the human homolog of Flk-2/Flt-3, is selectively expressed in CD34+ human bone marrow cells and is involved in the proliferation of early progenitor/stem cells.

PubMed Central

Small, D; Levenstein, M; Kim, E; Carow, C; Amin, S; Rockwell, P; Witte, L; Burrow, C; Ratajczak, M Z; Gewirtz, A M

1994-01-01

We cloned the cDNA for stem cell tyrosine kinase 1 (STK-1), the human homolog of murine Flk-2/Flt-3, from a CD34+ hematopoietic stem cell-enriched library and investigated its expression in subsets of normal human bone marrow. The cDNA encodes a protein of 993 aa with 85% identity and 92% similarity to Flk-2/Flt-3. STK-1 is a member of the type III receptor tyrosine kinase family that includes KIT (steel factor receptor), FMS (colony-stimulating factor 1R), and platelet-derived growth factor receptor. STK-1 expression in human blood and marrow is restricted to CD34+ cells, a population greatly enriched for stem/progenitor cells. Anti-STK-1 antiserum recognizes polypeptides of 160 and 130 kDa in several STK-1-expressing cell lines and in 3T3 cells transfected with a STK-1 expression vector. Antisense oligonucleotides directed against STK-1 sequences inhibited hematopoietic colony formation, most strongly in long-term bone marrow cultures. These data suggest that STK-1 may function as a growth factor receptor on hematopoietic stem and/or progenitor cells. Images Fig. 2 Fig. 3 Fig. 4 PMID:7507245

Triazolopyrimidine (trapidil), a platelet-derived growth factor antagonist, inhibits parathyroid bone disease in an animal model for chronic hyperparathyroidism

NASA Technical Reports Server (NTRS)

Lotinun, Sutada; Sibonga, Jean D.; Turner, Russell T.

2003-01-01

Parathyroid bone disease in humans is caused by chronic hyperparathyroidism (HPT). Continuous infusion of PTH into rats results in histological changes similar to parathyroid bone disease, including increased bone formation, focal bone resorption, and severe peritrabecular fibrosis, whereas pulsatile PTH increases bone formation without skeletal abnormalities. Using a cDNA microarray with over 5000 genes, we identified an association between increased platelet-derived growth factor-A (PDGF-A) signaling and PTH-induced bone disease in rats. Verification of PDGF-A overexpression was accomplished with a ribonuclease protection assay. Using immunohistochemistry, PDGF-A peptide was localized to mast cells in PTH-treated rats. We also report a novel strategy for prevention of parathyroid bone disease using triazolopyrimidine (trapidil). Trapidil, an inhibitor of PDGF signaling, did not have any effect on indexes of bone turnover in normal rats. However, dramatic reductions in marrow fibrosis and bone resorption, but not bone formation, were observed in PTH-treated rats given trapidil. Also, trapidil antagonized the PTH-induced increases in mRNA levels for PDGF-A. These results suggest that PDGF signaling is important for the detrimental skeletal effects of HPT, and drugs that target the cytokine or its receptor might be useful in reducing or preventing parathyroid bone disease.

Electromechanical properties of human osteoarthritic and asymptomatic articular cartilage are sensitive and early detectors of degeneration.

PubMed

Hadjab, I; Sim, S; Karhula, S S; Kauppinen, S; Garon, M; Quenneville, E; Lavigne, P; Lehenkari, P P; Saarakkala, S; Buschmann, M D

2018-03-01

To evaluate cross-correlations of ex vivo electromechanical properties with cartilage and subchondral bone plate thickness, as well as their sensitivity and specificity regarding early cartilage degeneration in human tibial plateau. Six pairs of tibial plateaus were assessed ex vivo using an electromechanical probe (Arthro-BST) which measures a quantitative parameter (QP) reflecting articular cartilage compression-induced streaming potentials. Cartilage thickness was then measured with an automated thickness mapping technique using Mach-1 multiaxial mechanical tester. Subsequently, a visual assessment was performed by an experienced orthopedic surgeon using the International Cartilage Repair Society (ICRS) grading system. Each tibial plateau was finally evaluated with μCT scanner to determine the subchondral-bone plate thickness over the entire surface. Cross-correlations between assessments decreased with increasing degeneration level. Moreover, electromechanical QP and subchondral-bone plate thickness increased strongly with ICRS grade (ρ = 0.86 and ρ = 0.54 respectively), while cartilage thickness slightly increased (ρ = 0.27). Sensitivity and specificity analysis revealed that the electromechanical QP is the most performant to distinguish between different early degeneration stages, followed by subchondral-bone plate thickness and then cartilage thickness. Lastly, effect sizes of cartilage and subchondral-bone properties were established to evaluate whether cartilage or bone showed the most noticeable changes between normal (ICRS 0) and each early degenerative stage. Thus, the effect sizes of cartilage electromechanical QP were almost twice those of the subchondral-bone plate thickness, indicating greater sensitivity of electromechanical measurements to detect early osteoarthritis. The potential of electromechanical properties for the diagnosis of early human cartilage degeneration was highlighted and supported by cartilage thickness and μCT assessments. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

The short-term effects of cisplatin chemotherapy on bone turnover.

PubMed

Young, D R; Virolainen, P; Inoue, N; Frassica, F J; Chao, E Y

1997-11-01

Cisplatin is an effective agent in the treatment of osteosarcoma of bone but little is known of its effects on normal bone turnover. Twenty-four dogs divided into three study groups were used to study the effect of cisplatin on normal bone turnover at the distant site of surgery. Group 1 served as the control group, group 2 received four cycles of cisplatin every 3 weeks before the surgery, and group 3 received four cycles postoperatively. The bone turnover rate was evaluated by measuring levels of systemic bone markers, osteocalcin, alkaline phospohatase, urine pyridinoline cross-links, and by determination histomorphometric indices. Histomorphological analysis showed poor correlation on bone formation with systemic bone markers at distant sites of surgery. Histomorphometrically normal bone turnover was affected by administration of cisplatin, but the effect was temporary, late, and less significant than what occurred at the surgical site. Our data showed that significant effects of cisplatin are observed at the site of active cellular induction and proliferation, such as implant-host interface, and less effects are seen at the sites of normal bone turnover.

Sphere-shaped nano-hydroxyapatite/chitosan/gelatin 3D porous scaffolds increase proliferation and osteogenic differentiation of human induced pluripotent stem cells from gingival fibroblasts.

PubMed

Ji, Jun; Tong, Xin; Huang, Xiaofeng; Wang, Tiancong; Lin, Zitong; Cao, Yazhou; Zhang, Junfeng; Dong, Lei; Qin, Haiyan; Hu, Qingang

2015-07-08

Hydroxyapatite (HA) is an important component of human bone and bone tissue engineering scaffolds. A plethora of bone tissue engineering scaffolds have been synthesized so far, including nano-HA/chitosan/gelatin (nHA/CG) scaffolds; and for seeding cells, stem cells, especially induced pluripotent stem cells (iPSCs), have been a promising cell source for bone tissue engineering recently. However, the influence of different HA nano-particle morphologies on the osteogenic differentiation of human iPSCs (hiPSCs) from human gingival fibroblasts (hGFs) is unknown. The purpose of this study was to investigate the osteogenic differentiation of hiPSCs from hGFs seeded on nHA/CG scaffolds with 2 shapes (rod and sphere) of nHA particles. Firstly, hGFs isolated from discarded normal gingival tissues were reprogrammed into hiPSCs. Secondly, hiPSCs were seeded on rod-like nHA/CG (rod-nHA/CG) and sphere-shaped nHA/CG (sphere-nHA/CG) scaffolds respectively and then cell/scaffold complexes were cultured in vitro. Scanning electron microscope, hematoxyline and eosin (HE) staining, Masson's staining, and quantitative real-time polymerase chain reaction techniques were used to examine hiPSC morphology, proliferation, and differentiation on rod-nHA/CG and sphere-nHA/CG scaffolds. Finally, hiPSCs composited with 2 kinds of nHA/CG were transplanted in vivo in a subcutaneous implantation model for 12 weeks; pure scaffolds were also transplanted as a blank control. HE, Masson's, and immunohistochemistry staining were applied to detect new bone regeneration ability. The results showed that sphere-nHA/CG significantly increased hiPSCs from hGF proliferation and osteogenic differentiation in vitro. hiPSCs and sphere-nHA/CG composities generated large bone, whereas hiPSCs and rod-nHA/CG composities produced tiny bone in vivo. Moreover, pure scaffolds without cells almost produced no bone. In conclusion, our work provided a potential innovative bone tissue engineering approach using clinically discarded gingival tissues and sphere-nHA/CG scaffolds.

The role of barrier membranes for guided bone regeneration and restoration of large bone defects: current experimental and clinical evidence

PubMed Central

2012-01-01

Treatment of large bone defects represents a great challenge in orthopedic and craniomaxillofacial surgery. Although there are several methods for bone reconstruction, they all have specific indications and limitations. The concept of using barrier membranes for restoration of bone defects has been developed in an effort to simplify their treatment by offering a sinlge-staged procedure. Research on this field of bone regeneration is ongoing, with evidence being mainly attained from preclinical studies. The purpose of this review is to summarize the current experimental and clinical evidence on the use of barrier membranes for restoration of bone defects in maxillofacial and orthopedic surgery. Although there are a few promising preliminary human studies, before clinical applications can be recommended, future research should aim to establish the 'ideal' barrier membrane and delineate the need for additional bone grafting materials aiming to 'mimic' or even accelerate the normal process of bone formation. Reproducible results and long-term observations with barrier membranes in animal studies, and particularly in large animal models, are required as well as well-designed clinical studies to evaluate their safety, efficacy and cost-effectiveness. PMID:22834465

Reduced vertebral bone density in hypercalciuric nephrolithiasis

NASA Technical Reports Server (NTRS)

Pietschmann, F.; Breslau, N. A.; Pak, C. Y.

1992-01-01

Dual-energy x-ray absorptiometry and single-photon absorptiometry were used to determine bone density at the lumbar spine and radial shaft in 62 patients with absorptive hypercalciuria, 27 patients with fasting hypercalciuria, and 31 nonhypercalciuric stone formers. Lumbar bone density was significantly lower in patients with absorptive (-10%) as well as in those with fasting hypercalciuria (-12%), with 74 and 92% of patients displaying values below the normal mean, whereas only 48% of the nonhypercalciuric stone formers had bone density values below the normal mean. In contrast, radial bone density was similar in all three groups of renal stone formers investigated. The comparison of urinary chemistry in patients with absorptive hypercalciuria and low normal bone density compared to those with high normal bone density showed a significantly increased 24 h urinary calcium excretion on random diet and a trend toward a higher 24 h urinary uric acid excretion and a higher body mass index in patients with low normal bone density. Moreover, among the patients with absorptive hypercalciuria we found a statistically significant correlation between the spinal bone density and the 24 h sodium and sulfate excretion and the urinary pH. These results gave evidence for an additional role of environmental factors (sodium and animal proteins) in the pathogenesis of bone loss in absorptive hypercalciuria. In conclusion, our data suggest an osteopenia of trabecular-rich bone tissues in patients with fasting and absorptive hypercalciurias.

Improvement of anemia in W/WV mice by recombinant human erythropoietin (rHuEPO) mediated through EPO receptors with lowered affinity.

PubMed

Kabaya, K; Akiyama, H; Nishi, N; Misaizu, T; Okada, Y; Kawagishi, M; Amano, K; Kusaka, M; Seki, M; Uzumaki, H

1995-01-01

We studied the effects of recombinant human erythropoietin (rHuEPO) on anemic W/WV mice which manifested severe anemia accompanied by mutation of the W gene encoding tyrosine kinase type receptor (c-kit gene) of bone marrow hematopoietic cells. Nine-week-old male W/WV mice or normal littermates (+/+) were used. Since serum EPO concentration in W/WV mice increased in proportion to severity of anemia, EPO production in the kidneys of these animals was found to be regulated normally. Hematocrit in +/+ mice increased and a maximal response was also obtained with 2,000 IU/kg of rHuEPO. On the other hand, hematocrit in W/WV mice increased in a dose-responsive manner by administration with 2,000 and 10,000 IU/kg, showing different responses to rHuEPO in these two types of mice. The responsiveness of W/WV mice to rHuEPO was low in terms of increases in erythroblastic precursor cells (CFU-E), and immature cells in the bone marrow. Scatchard analysis of the specific binding of 125I-rHuEPO against bone marrow cells revealed that the different responsiveness to rHuEPO between W/WV and +/+ mice may be correlated with differences in affinity of EPO receptor of bone marrow cells in these mice. From these results, a high dose of rHuEPO is capable of improving the anemia in W/WV mice that had EPO receptors with lowered affinity, indicating the possible effectiveness of rHuEPO in anemic patients with EPO receptor abnormality.

Experiment K305: Quantitative analysis of selected bone parameters. Supplement 2: Bone elongation rate and bone mass in metaphysis of long bones

NASA Technical Reports Server (NTRS)

Jee, W. S. S.; Kimmel, D. B.; Smith, C.; Dell, R. B.

1981-01-01

The proximal humeral metaphysis of rats from time periods recovery plus zero days (R+0), recovery plus six days (R+6), and recovery plus twenty nine days (R+29) was analyzed. The volume of calcified cartilage and bone in flight and synchronous controls was reduced in groups R+0 and R+6, but was normal in group R+29. The number of functional bone cells (osteoblasts and osteoclasts) was decreased in proportion to the amount of bone in the early groups, and was normal in the last group. The fatty marrow volume was increased only in flight animals of groups R+0 and R+6, but was normal in the R+29 group. Accumulation of excess fatty marrow was seen only in flight animals. The decreased amount of bone and calcified cartilage is believed to be the result of a temporarily slowed or arrested production of calcified cartilage as a substrate for bone formation. This would have resulted from slowed bone elongation during flight and synchronous control conditions. Bone elongation returned to normal by twenty nine days after return.

Co-Targeting Prostate Cancer Epithelium and Bone Stroma by Human Osteonectin-Promoter-Mediated Suicide Gene Therapy Effectively Inhibits Androgen-Independent Prostate Cancer Growth.

PubMed

Sung, Shian-Ying; Chang, Junn-Liang; Chen, Kuan-Chou; Yeh, Shauh-Der; Liu, Yun-Ru; Su, Yen-Hao; Hsueh, Chia-Yen; Chung, Leland W K; Hsieh, Chia-Ling

2016-01-01

Stromal-epithelial interaction has been shown to promote local tumor growth and distant metastasis. We sought to create a promising gene therapy approach that co-targets cancer and its supporting stromal cells for combating castration-resistant prostate tumors. Herein, we demonstrated that human osteonectin is overexpressed in the prostate cancer epithelium and tumor stroma in comparison with their normal counterpart. We designed a novel human osteonectin promoter (hON-522E) containing positive transcriptional regulatory elements identified in both the promoter and exon 1 region of the human osteonectin gene. In vitro reporter assays revealed that the hON-522E promoter is highly active in androgen receptor negative and metastatic prostate cancer and bone stromal cells compared to androgen receptor-positive prostate cancer cells. Moreover, in vivo prostate-tumor-promoting activity of the hON-522E promoter was confirmed by intravenous administration of an adenoviral vector containing the hON-522E promoter-driven luciferase gene (Ad-522E-Luc) into mice bearing orthotopic human prostate tumor xenografts. In addition, an adenoviral vector with the hON-522E-promoter-driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. Because of the heterogeneity of human prostate tumors, hON-522E promoter-mediated gene therapy has the potential for the treatment of hormone refractory and bone metastatic prostate cancers.

Proliferative Potentials of Bone Marrow and Blood Cells Studied by in vitro Uptake of H 3-Thymidine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bond, V. P.; Fliedner, T. M.; Cronkite, E. P.

1959-01-01

Cell proliferative activity and potential in the circulating blood and in the bone marrow of individuals with normal hematopoiesis, and in patients with hematopoietic dyscrasias was studied by means of in vitro one hour incubation with tritiated thymidine (H 3Th) and 6tripping film autoradiography. The labeled material is incorporated only into DNA during synthesis. In normal bone marrow, labeling was seen at 1 hour in all cell lineages, and in cells variously referred to as "reticulum," "stem,'' " stroma,'' etc., cells. Erythropoietic cells were labeled as far as the polychromatic normoblast; the myeloid series was labeled to the myelocyte state.more » Leukemia cells in the bone marrow and peripheral blood of patients with acute or chronic myelocytic leukemia incorporated label avidly; the small typical leukemia cell of chronic lymphocytic leukemia did not label at all. Less than 3 per cent of the myeloma cells in patients with multiple myeloma incorporated thymidine. Most striking was the finding of small numbers of labeled large mononuclear cells of different morphological types in the peripheral blood of normal human beings, and an increase in the number of morphologically identical cells in the blood of patients with infection and infectious mononucleosis. The labeling indicates active DNA synthesis and thus these cells presumably are capable of division. It is suggested that these cells may represent a mobile pool of primitive progenitor cells and are multipotential in their function.« less

Sex-specific quantitative trait loci contribute to normal variation in bone structure at the proximal femur in men

PubMed Central

Peacock, Munro; Koller, Daniel L.; Lai, Dongbing; Hui, Siu; Foroud, Tatiana; Econs, Michael J.

2006-01-01

Bone structure is an important determinant of osteoporotic fracture. In women bone structure is highly heritable and several quantitative trait loci (QTL) have been reported. There are few comparable data in men. This study in men aimed at establishing the heritability of bone structure at the proximal femur, identifying QTL contributing to normal variation in bone structure, and determining which QTL might be sex-specific. Bone structure at the proximal femur was measured in 205 pairs of brothers age 18–61. Heritability was calculated and linkage analysis performed on phenotypes at the proximal femur. Heritability estimates ranged from 0.99 to 0.39. A genome wide scan identified suggestive QTL (LOD>2.2) for femoral shaft width on chromosome 14q (LOD=2.69 at position 99cM), calcar femorale at chromosome 2p (LOD= 3.97 at position 194cM) and at the X chromosome (LOD= 3.01 at position 77cM), femoral neck width on chromosome 5p (LOD=2.28 at position 0 cM), femoral head width on chromosome 11q (LOD=2.30 at position 131 cM) and 15q (LOD=3.11 at position 90 cM), and pelvic axis length on chromosome 4q (LOD= 4.16 at 99cM) and 17q (LOD=2.80 at position 112 cM). Comparison with published data in 437 pairs of premenopausal sisters from the same geographical region suggested that 3 of the 7 autosomal QTL were male-specific. This study demonstrates that bone structure at the proximal femur in healthy men is highly heritable. The occurrence of sex-specific genes in humans for bone structure has important implications for the pathogenesis and treatment of osteoporosis. PMID:16046210

cDNA cloning of the murine PEX gene implicated in X-linked hypophosphatemia and evidence for expression in bone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, L.; Desbarats, M.; Viel, J.

1996-08-15

The recently identified human PEX g ene apparently encodes for a neutral endopeptidase that is mutated in patients with X-linked hypophosphatemia. The 3{prime} and 5{prime} ends of the coding region of PEX have not been cloned, nor has the tissue expression of the gene been identified. Here we report the isolation and characterization of the complete open reading frame of the mouse Pex gene and the demonstration of its expression in bone. Mouse Pex cDNA is predicted to encode a protein of 749 amino acids with 95% identity to the available human PEX sequence and significant homology to members ofmore » the membrane-bound metalloendopeptidase family. Northern blot analysis revealed a 6.6-kb transcript in bone and in cultured osteoblasts from normal mice that was not detectable in samples from the Hyp mouse, the murine homolog of human X-linked hypophosphatemia. Pex transcripts were, however, detectable in Hyp bone by RT-PCR amplification. Of particular interest, a cDNA clone from rat incisor shows 93% sequence identity to the 5{prime} end of Pex cDNA, suggesting that Pex may be expressed in another calcified tissue, the tooth. The association of impaired mineralization of bone and teeth and disturbed renal phosphate reabsorption with altered expression of Pex suggests that the Pex gene product may play a critical role in these processes. 47 refs., 2 figs., 1 tab.« less

Models of tibial fracture healing in normal and Nf1-deficient mice.

PubMed

Schindeler, Aaron; Morse, Alyson; Harry, Lorraine; Godfrey, Craig; Mikulec, Kathy; McDonald, Michelle; Gasser, Jürg A; Little, David G

2008-08-01

Delayed union and nonunion are common complications associated with tibial fractures, particularly in the distal tibia. Existing mouse tibial fracture models are typically closed and middiaphyseal, and thus poorly recapitulate the prevailing conditions following surgery on a human open distal tibial fracture. This report describes our development of two open tibial fracture models in the mouse, where the bone is broken either in the tibial midshaft (mid-diaphysis) or in the distal tibia. Fractures in the distal tibial model showed delayed repair compared to fractures in the tibial midshaft. These tibial fracture models were applied to both wild-type and Nf1-deficient (Nf1+/-) mice. Bone repair has been reported to be exceptionally problematic in human NF1 patients, and these patients can also spontaneously develop tibial nonunions (known as congenital pseudarthrosis of the tibia), which are recalcitrant to even vigorous intervention. pQCT analysis confirmed no fundamental differences in cortical or cancellous bone in Nf1-deficient mouse tibiae compared to wild-type mice. Although no difference in bone healing was seen in the tibial midshaft fracture model, the healing of distal tibial fractures was found to be impaired in Nf1+/- mice. The histological features associated with nonunited Nf1+/- fractures were variable, but included delayed cartilage removal, disproportionate fibrous invasion, insufficient new bone anabolism, and excessive catabolism. These findings imply that the pathology of tibial pseudarthrosis in human NF1 is complex and likely to be multifactorial.

Long-term in vitro correction of alpha-L-iduronidase deficiency (Hurler syndrome) in human bone marrow.

PubMed Central

Fairbairn, L J; Lashford, L S; Spooncer, E; McDermott, R H; Lebens, G; Arrand, J E; Arrand, J R; Bellantuono, I; Holt, R; Hatton, C E; Cooper, A; Besley, G T; Wraith, J E; Anson, D S; Hopwood, J J; Dexter, T M

1996-01-01

Allogeneic bone marrow transplantation is the most effective treatment for Hurler syndrome but, since this therapy is not available to all patients, we have considered an alternative approach based on transfer and expression of the normal gene in autologous bone marrow. A retroviral vector carrying the full-length cDNA for alpha-L-iduronidase has been constructed and used to transduce bone marrow from patients with this disorder. Various gene-transfer protocols have been assessed including the effect of intensive schedules of exposure of bone marrow to viral supernatant and the influence of growth factors. With these protocols, we have demonstrated successful gene transfer into primitive CD34+ cells and subsequent enzyme expression in their maturing progeny. Also, by using long-term bone marrow cultures, we have demonstrated high levels of enzyme expression sustained for several months. The efficiency of gene transfer has been assessed by PCR analysis of hemopoietic colonies as 25-56%. No advantage has been demonstrated for the addition of growth factors or intensive viral exposure schedules. The enzyme is secreted into the medium and functional localization has been demonstrated by reversal of the phenotypic effects of lysosomal storage in macrophages. This work suggests that retroviral gene transfer into human bone marrow may offer the prospect for gene therapy of Hurler syndrome in young patients without a matched sibling donor. Images Fig. 2 Fig. 4 Fig. 7 Fig. 8 PMID:8700879

The gut microbiota regulates bone mass in mice

PubMed Central

Sjögren, Klara; Engdahl, Cecilia; Henning, Petra; Lerner, Ulf H; Tremaroli, Valentina; Lagerquist, Marie K; Bäckhed, Fredrik; Ohlsson, Claes

2012-01-01

The gut microbiota modulates host metabolism and development of immune status. Here we show that the gut microbiota is also a major regulator of bone mass in mice. Germ-free (GF) mice exhibit increased bone mass associated with reduced number of osteoclasts per bone surface compared with conventionally raised (CONV-R) mice. Colonization of GF mice with a normal gut microbiota normalizes bone mass. Furthermore, GF mice have decreased frequency of CD4+ T cells and CD11b+/GR 1 osteoclast precursor cells in bone marrow, which could be normalized by colonization. GF mice exhibited reduced expression of inflammatory cytokines in bone and bone marrow compared with CONV-R mice. In summary, the gut microbiota regulates bone mass in mice, and we provide evidence for a mechanism involving altered immune status in bone and thereby affected osteoclast-mediated bone resorption. Further studies are required to evaluate the gut microbiota as a novel therapeutic target for osteoporosis. © 2012 American Society for Bone and Mineral Research. PMID:22407806

Homogeneous antibodies in lethally irradiated and autologous bone marrow reconstituted Rhesus monkeys

PubMed Central

Van Den Berg, Pleuntje; Radl, J.; Löwenberg, B.; Swart, A. C. W.

1976-01-01

Ten Rhesus monkeys were lethally irradiated and reconstituted with autologous bone marrow. During the restoration period, the animals were immunized with DNP–Rhesus albumin and IgA1λ-10S human paraprotein. One or more transient homogeneous immunoglobulin components appeared in sera of all experimental monkeys. In four animals, these homogeneous immunoglobulins were shown to be specific antibodies against DNP–Rhesus albumin. They gradually became as heterogeneous as those in control monkeys which were immunized but not irradiated and transplanted. The onset of the specific antibody response after immunization was slightly delayed in the experimental group. On determining the time necessary to reach normalization of the overall immunoglobulin levels and the normal heterogeneity of the immunoglobulin spectrum, it was found to be more than 1 year in most of the animals. ImagesFig. 1

Hematopoiesis in 3 dimensions: human and murine bone marrow architecture visualized by confocal microscopy.

PubMed

Takaku, Tomoiku; Malide, Daniela; Chen, Jichun; Calado, Rodrigo T; Kajigaya, Sachiko; Young, Neal S

2010-10-14

In many animals, blood cell production occurs in the bone marrow. Hematopoiesis is complex, requiring self-renewing and pluripotent stem cells, differentiated progenitor and precursor cells, and supportive stroma, adipose tissue, vascular structures, and extracellular matrix. Although imaging is a vital tool in hematology research, the 3-dimensional architecture of the bone marrow tissue in situ remains largely uncharacterized. The major hindrance to imaging the intact marrow is the surrounding bone structures are almost impossible to cut/image through. We have overcome these obstacles and describe a method whereby whole-mounts of bone marrow tissue were immunostained and imaged in 3 dimensions by confocal fluorescence and reflection microscopy. We have successfully mapped by multicolor immunofluorescence the localization pattern of as many as 4 cell features simultaneously over large tiled views and to depths of approximately 150 μm. Three-dimensional images can be assessed qualitatively and quantitatively to appreciate the distribution of cell types and their interrelationships, with minimal perturbations of the tissue. We demonstrate its application to normal mouse and human marrow, to murine models of marrow failure, and to patients with aplastic anemia, myeloid, and lymphoid cell malignancies. The technique should be generally adaptable for basic laboratory investigation and for clinical diagnosis of hematologic diseases.

Molecular study on human tuberculosis in three geographically distinct and time delineated populations from ancient Egypt.

PubMed Central

Zink, A. R.; Grabner, W.; Reischl, U.; Wolf, H.; Nerlich, A. G.

2003-01-01

We describe the molecular identification of human tuberculosis (TB) from vertebral bone tissue samples from three different populations of ancient Egypt. The specimens were obtained from the predynastic to early dynastic necropolis of Abydos (7 individuals, c. 3500-2650 B.C.), from a Middle Kingdom to Second Intermediate Period tomb of the necropolis of Thebes-West (37. c. 2100-1550 B.C.) and from five further Theban tombs used in the New Kingdom and the Late Period (39, c. 1450-500 B.C.). A total of 18 cases tested positive for the presence of ancient DNA (aDNA) of the M. tuberculosis complex. Out of the 9 cases with typical macromorphological signs of tuberculous spondylitis, 6 were positive for mycobacterial aDNA (66.7%). Of 24 cases with non-specific pathological alterations, 5 provided a positive result (20.8%). In 50 cases of normally appearing vertebral bones 7 tested positive (14.0%). There were only minor differences in the frequencies between the three populations. These data strongly support the notion that tuberculosis was present and prevalent in ancient Egypt since very early periods of this civilization. The unexpectedly high rate of mycobacterial aDNA in normal bone samples is presumably due to a pre- to perimortal systemic spread of the bacteria and indicates a generalized infection by M. tuberculosis. PMID:12729192

Cytomegalovirus infection of the BS-1 human stroma cell line: effect on murine hemopoiesis.

PubMed

Steinberg, H N; Anderson, J; Lim, B; Chatis, P A

1993-10-01

BS-1, a stromal cell line derived from human bone marrow, can support the growth of murine erythroid (BFU-E), granulocyte-macrophage (CFU-GM), and megakaryocyte (CFU-M) progenitor cells in a short term in vitro coculture system. Exposure of BS-1 cells to cytomegalovirus (CMV) for 3 hr prior to coculture results in a marked reduction in the stroma cell's ability to support murine hemopoiesis. CMV's effect on the BS-1 cell's hematopoietic support function is dependent on the multiplicity of infection with total suppression of BFU-E observed at a 1:1 ratio of virus to bone marrow cells. A 50% loss in the ability of BS-1 cells to support BFU-E is observed at a 0.1:1 ratio. No effect of CMV is observed with further log dilutions of virus. CMV infection of BS-1 cells affects its support of erythroid progenitor cell growth to a greater extent than its influence on the development of granulocyte-macrophage colonies. Antibody to CMV or heat inactivation of the virus reverses the inhibitory affect on BS-1 cells. The results suggest that CMV can infect a cell that constitutes one of the cellular elements of the normal bone marrow microenvironment causing a decrease in the stroma's ability to support the growth and development of normal progenitor cells.

Human growth is associated with distinct patterns of gene expression in evolutionarily conserved networks

PubMed Central

2013-01-01

Background A co-ordinated tissue-independent gene expression profile associated with growth is present in rodent models and this is hypothesised to extend to all mammals. Growth in humans has similarities to other mammals but the return to active long bone growth in the pubertal growth spurt is a distinctly human growth event. The aim of this study was to describe gene expression and biological pathways associated with stages of growth in children and to assess tissue-independent expression patterns in relation to human growth. Results We conducted gene expression analysis on a library of datasets from normal children with age annotation, collated from the NCBI Gene Expression Omnibus (GEO) and EBI Arrayexpress databases. A primary data set was generated using cells of lymphoid origin from normal children; the expression of 688 genes (ANOVA false discovery rate modified p-value, q < 0.1) was associated with age, and subsets of these genes formed clusters that correlated with the phases of growth – infancy, childhood, puberty and final height. Network analysis on these clusters identified evolutionarily conserved growth pathways (NOTCH, VEGF, TGFB, WNT and glucocorticoid receptor – Hyper-geometric test, q < 0.05). The greatest degree of network ‘connectivity’ and hence functional significance was present in infancy (Wilcoxon test, p < 0.05), which then decreased through to adulthood. These observations were confirmed in a separate validation data set from lymphoid tissue. Similar biological pathways were observed to be associated with development-related gene expression in other tissues (conjunctival epithelia, temporal lobe brain tissue and bone marrow) suggesting the existence of a tissue-independent genetic program for human growth and maturation. Conclusions Similar evolutionarily conserved pathways have been associated with gene expression and child growth in multiple tissues. These expression profiles associate with the developmental phases of growth including the return to active long bone growth in puberty, a distinctly human event. These observations also have direct medical relevance to pathological changes that induce disease in children. Taking into account development-dependent gene expression profiles for normal children will be key to the appropriate selection of genes and pathways as potential biomarkers of disease or as drug targets. PMID:23941278

In vitro osteoblastic differentiation of human bone marrow cells in the presence of metal ions.

PubMed

Morais, S; Dias, N; Sousa, J P; Fernandes, M H; Carvalho, G S

1999-02-01

For periods up to 21 days human bone marrow was cultured in control conditions that favor the proliferation and differentiation of osteoblastic cells. The effect of AISI 316L corrosion products and the corresponding major separate metal ions (Fe, Cr, and Ni) were studied in three different phases of the culture period in order to investigate the effects of metal ions in cell populations representative of osteoblastic cells in different stages of differentiation. Toxicity consequences of the presence of metal ions in bone marrow cultures were evaluated by biochemical parameters (enzymatic reduction of MTT, alkaline phosphatase activity, and total protein content), histochemical assays (identification of ALP-positive cells and Ca and phosphates deposits), and observation of the cultures by light and scanning electron microscopy. Culture media were analyzed for total and ionized Ca and P and also for metal ions (Fe, Cr, and Ni). The presence of AISI 316L corrosion products and Ni salt in bone marrow cultures during the first and second weeks of culture significantly disturbs the normal behavior of these cultures, interfering in the lag phase and exponential phase of cell growth and ALP expression. However, the presence of these species during the third week of culture, when expression of osteoblastic functions occurs (mineralization process), did not result in any detectable effect. Fe salt also disturbs the behavior of bone marrow cell cultures when present during the lag phase and proliferation phase, and a somewhat compromised response between the normal pattern (control cultures) and intense inhibition (AISI 316L corrosion products and Ni salt-added cultures) was observed. Fe did not affect the progression of the mineralization phase. Osteogenic cultures exposed to Cr salt (Cr3+) presented a pattern similar to the controls, indicating that this element does not interfere, in the concentration studied, in the osteoblastic differentiation of bone marrow cells. Quantification of metal ions in the culture media showed that Cr (originated from AISI 316L corrosion products but from not Cr3+ salt) and Ni (originated from AISI 316L corrosion products and Ni salt) appear to be retained by the bone marrow cultures. Copyright 1999 John Wiley & Sons, Inc.

Homing of human B cells to lymphoid organs and B-cell lymphoma engraftment are controlled by cell adhesion molecule JAM-C.

PubMed

Doñate, Carmen; Ody, Christiane; McKee, Thomas; Ruault-Jungblut, Sylvie; Fischer, Nicolas; Ropraz, Patricia; Imhof, Beat A; Matthes, Thomas

2013-01-15

Junctional adhesion molecule C (JAM-C) is expressed by vascular endothelium and human but not mouse B lymphocytes. The level of JAM-C expression defines B-cell differentiation stages and allows the classification of marginal zone-derived (JAM-C-positive) and germinal center-derived (JAM-C-negative) B-cell lymphomas. In the present study, we investigated the role of JAM-C in homing of human B cells, using a xenogeneic nonobese diabetic/severe combined immunodeficient mouse model. Treatment with anti-JAM-C antibodies in short-term experiments reduced migration of normal and malignant JAM-C-expressing B cells to bone marrow, lymph nodes, and spleen. Blocking homing to the spleen is remarkable, as most other antiadhesion antibodies reduce homing of B cells only to bone marrow and lymph nodes. Long-term administration of anti-JAM-C antibodies prevented engraftment of JAM-Cpos lymphoma cells in bone marrow, spleen, and lymph nodes of mice. Plasmon resonance studies identified JAM-B as the major ligand for JAM-C, whereas homotypic JAM-C interactions remained at background levels. Accordingly, anti-JAM-C antibodies blocked adhesion of JAM-C-expressing B cells to their ligand JAM-B, and immunofluorescence analysis showed the expression of JAM-B on murine and human lymphatic endothelial cells. Targeting JAM-C could thus constitute a new therapeutic strategy to prevent lymphoma cells from reaching supportive microenvironments not only in the bone marrow and lymph nodes but also in the spleen.

CA-45 AND Sr-85 METABOLISM IN MAN. Progress Report for June 15, 1959- May 20, 1960

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1960-10-31

Bone formation rate in a normal, healthy, young adult was observed to be 0.521 g calcium/day. Calcium balance and bone formation and destruction rates were studied in patients with disuse osetoporosis associated with quadriplegia secondary to poliomyelitis and patients with senile and posmenopausal osteoporosis. Renal strontium/calcium discrimination, studied for nine cases, was given by a mean factor of 4.3. This factor means that, exposed to trace amounts of strontium and normal calcium loads, the human kidney will produce a urine containing 4.3 atoms of strontium per unit filtered strontium for each atom calcium per unit filtered calcium. The mean valuemore » for gastrointestinal discrimination between endogenously secreted Sr/sup 85/ and Ca/sup 45/ was 1.4. The ratio of strontium-determined pool to calcium- determined pool was 1.04 plus or minus 0.13 (1 S.D.) and the corresponding ratio for bone formation values was 1.04 plus or minus 0.32 (1 S.D.) for nine patients studied. (C.J.G.)« less

Effect of GH/IGF-1 on Bone Metabolism and Osteoporsosis

PubMed Central

Locatelli, Vittorio; Bianchi, Vittorio E.

2014-01-01

Background. Growth hormone (GH) and insulin-like growth factor (IGF-1) are fundamental in skeletal growth during puberty and bone health throughout life. GH increases tissue formation by acting directly and indirectly on target cells; IGF-1 is a critical mediator of bone growth. Clinical studies reporting the use of GH and IGF-1 in osteoporosis and fracture healing are outlined. Methods. A Pubmed search revealed 39 clinical studies reporting the effects of GH and IGF-1 administration on bone metabolism in osteopenic and osteoporotic human subjects and on bone healing in operated patients with normal GH secretion. Eighteen clinical studies considered the effect with GH treatment, fourteen studies reported the clinical effects with IGF-1 administration, and seven related to the GH/IGF-1 effect on bone healing. Results. Both GH and IGF-1 administration significantly increased bone resorption and bone formation in the most studies. GH/IGF-1 administration in patients with hip or tibial fractures resulted in increased bone healing, rapid clinical improvements. Some conflicting results were evidenced. Conclusions. GH and IGF-1 therapy has a significant anabolic effect. GH administration for the treatment of osteoporosis and bone fractures may greatly improve clinical outcome. GH interacts with sex steroids in the anabolic process. GH resistance process is considered. PMID:25147565

The orthotropic elastic properties of fibrolamellar bone tissue in juvenile white-tailed deer femora

PubMed Central

Barrera, John W.; Le Cabec, Adeline; Barak, Meir M.

2017-01-01

Fibrolamellar bone is a transient primary bone tissue found in fast growing juvenile mammals, several species of birds and large dinosaurs. Despite the fact that this bone tissue is prevalent in many species, the vast majority of bone structural and mechanical studies are focused on humans osteonal bone tissue. Previous research revealed the orthotropic structure of fibrolamellar bone, but only a handful of experiments investigated its elastic properties, mostly in the axial direction. Here we have performed for the first time an extensive biomechanical study to determine the elastic properties of fibrolamellar bone in all three orthogonal directions. We have tested 30 fibrolamellar bone cubes (2×2×2mm) from the femora of five juvenile white-tailed deer (Odocoileus virginianus) in compression. Each bone cube was compressed iteratively, within its elastic region, in the axial, transverse and radial directions and bone stiffness (Young’s modulus) was recorded. Next, the cubes were kept for seven days at 4°C and then compressed again to test whether bone stiffness had significantly deteriorated. Our results demonstrated that bone tissue in the deer femora has orthotropic elastic behavior where the highest stiffness was in the axial direction followed by the transverse and the radial directions respectively (21.6±3.3 GPa, 17.6±3.0 GPa and 14.9±1.9 GPa respectively). Our results also revealed a slight non-significant decrease in bone stiffness after seven days. Finally, our sample size allowed us to establish that population variance was much bigger in the axial direction compared to the radial direction which potentially reflects bone adaptation to the large diversity in loading activity between individuals in the loading direction (axial) compared to the normal (radial) direction. This study confirms that the well mechanically-studied human transverse-isotropic osteonal bone is just one possible functional adaptation of bone tissue and that other vertebrate species use an orthotropic bone tissue structure which is more suitable for their mechanical requirements. PMID:27231028

A STUDY OF PREDICTED BONE MARROW DISTRIBUTION ON CALCULATED MARROW DOSE FROM EXTERNAL RADIATION EXPOSURES USING TWO SETS OF IMAGE DATA FOR THE SAME INDIVIDUAL

PubMed Central

Caracappa, Peter F.; Chao, T. C. Ephraim; Xu, X. George

2010-01-01

Red bone marrow is among the tissues of the human body that are most sensitive to ionizing radiation, but red bone marrow cannot be distinguished from yellow bone marrow by normal radiographic means. When using a computational model of the body constructed from computed tomography (CT) images for radiation dose, assumptions must be applied to calculate the dose to the red bone marrow. This paper presents an analysis of two methods of calculating red bone marrow distribution: 1) a homogeneous mixture of red and yellow bone marrow throughout the skeleton, and 2) International Commission on Radiological Protection cellularity factors applied to each bone segment. A computational dose model was constructed from the CT image set of the Visible Human Project and compared to the VIP-Man model, which was derived from color photographs of the same individual. These two data sets for the same individual provide the unique opportunity to compare the methods applied to the CT-based model against the observed distribution of red bone marrow for that individual. The mass of red bone marrow in each bone segment was calculated using both methods. The effect of the different red bone marrow distributions was analyzed by calculating the red bone marrow dose using the EGS4 Monte Carlo code for parallel beams of monoenergetic photons over an energy range of 30 keV to 6 MeV, cylindrical (simplified CT) sources centered about the head and abdomen over an energy range of 30 keV to 1 MeV, and a whole-body electron irradiation treatment protocol for 3.9 MeV electrons. Applying the method with cellularity factors improves the average difference in the estimation of mass in each bone segment as compared to the mass in VIP-Man by 45% over the homogenous mixture method. Red bone marrow doses calculated by the two methods are similar for parallel photon beams at high energy (above about 200 keV), but differ by as much as 40% at lower energies. The calculated red bone marrow doses differ significantly for simplified CT and electron beam irradiation, since the computed red bone marrow dose is a strong function of the cellularity factor applied to bone segments within the primary radiation beam. These results demonstrate the importance of properly applying realistic cellularity factors to computation dose models of the human body. PMID:19430219

A study of predicted bone marrow distribution on calculated marrow dose from external radiation exposures using two sets of image data for the same individual.

PubMed

Caracappa, Peter F; Chao, T C Ephraim; Xu, X George

2009-06-01

Red bone marrow is among the tissues of the human body that are most sensitive to ionizing radiation, but red bone marrow cannot be distinguished from yellow bone marrow by normal radiographic means. When using a computational model of the body constructed from computed tomography (CT) images for radiation dose, assumptions must be applied to calculate the dose to the red bone marrow. This paper presents an analysis of two methods of calculating red bone marrow distribution: 1) a homogeneous mixture of red and yellow bone marrow throughout the skeleton, and 2) International Commission on Radiological Protection cellularity factors applied to each bone segment. A computational dose model was constructed from the CT image set of the Visible Human Project and compared to the VIP-Man model, which was derived from color photographs of the same individual. These two data sets for the same individual provide the unique opportunity to compare the methods applied to the CT-based model against the observed distribution of red bone marrow for that individual. The mass of red bone marrow in each bone segment was calculated using both methods. The effect of the different red bone marrow distributions was analyzed by calculating the red bone marrow dose using the EGS4 Monte Carlo code for parallel beams of monoenergetic photons over an energy range of 30 keV to 6 MeV, cylindrical (simplified CT) sources centered about the head and abdomen over an energy range of 30 keV to 1 MeV, and a whole-body electron irradiation treatment protocol for 3.9 MeV electrons. Applying the method with cellularity factors improves the average difference in the estimation of mass in each bone segment as compared to the mass in VIP-Man by 45% over the homogenous mixture method. Red bone marrow doses calculated by the two methods are similar for parallel photon beams at high energy (above about 200 keV), but differ by as much as 40% at lower energies. The calculated red bone marrow doses differ significantly for simplified CT and electron beam irradiation, since the computed red bone marrow dose is a strong function of the cellularity factor applied to bone segments within the primary radiation beam. These results demonstrate the importance of properly applying realistic cellularity factors to computation dose models of the human body.

The role of Fanconi anemia/BRCA genes in zebrafish sex determination.

PubMed

Rodríguez-Marí, Adriana; Postlethwait, John H

2011-01-01

Fanconi anemia (FA) is a human disease of bone marrow failure, leukemia, squamous cell carcinoma, and developmental anomalies, including hypogonadism and infertility. Bone marrow transplants improve hematopoietic phenotypes but do not prevent other cancers. FA arises from mutation in any of the 15 FANC genes that cooperate to repair double stranded DNA breaks by homologous recombination. Zebrafish has a single ortholog of each human FANC gene and unexpectedly, mutations in at least two of them (fancl and fancd1(brca2)) lead to female-to-male sex reversal. Investigations show that, as in human, zebrafish fanc genes are required for genome stability and for suppressing apoptosis in tissue culture cells, in embryos treated with DNA damaging agents, and in meiotic germ cells. The sex reversal phenotype requires the action of Tp53 (p53), an activator of apoptosis. These results suggest that in normal sex determination, zebrafish oocytes passing through meiosis signal the gonadal soma to maintain expression of aromatase, an enzyme that converts androgen to estrogen, thereby feminizing the gonad and the individual. According to this model, normal male and female zebrafish differ in genetic factors that control the strength of the late meiotic oocyte-derived signal, probably by regulating the number of meiotic oocytes, which environmental factors can also alter. Transcripts from fancd1(brca2) localize at the animal pole of the zebrafish oocyte cytoplasm and are required for normal oocyte nuclear architecture, for normal embryonic development, and for preventing ovarian tumors. Embryonic DNA repair and sex reversal phenotypes provide assays for the screening of small molecule libraries for therapeutic substances for FA. Copyright © 2011 Elsevier Inc. All rights reserved.

Human water, sodium, and calcium regulation during space flight and exercise

NASA Astrophysics Data System (ADS)

Doty, S. E.; Seagrave, R. C.

When one is exposed to microgravity, fluid which is normally pooled in the lower extremities is redistributed headward and weight bearing bones begin to demineralize due to reduced mechanical stresses. The kidney, which is the primary regulator of body fluid volume and composition, responds to the fluid shift and bone demineralization by increasing the urinary output of water, sodium, and calcium. This research involves developing a mathematical description of how water and electrolytes are internally redistributed and exchanged with the environment during space flight. This model consequently involves kidney function and the associated endocrine system. The model agrees well with actual data, including that a low sodium diet can prevent bone demineralization. Therefore, assumptions made to develop the model are most likely valid. Additionally, various levels of activity are also considered in the model since exercise may help to eliminate some of the undesired effects of space flight such as muscle atrophy and bone demineralization.

Human water, sodium, and calcium regulation during space flight and exercise

NASA Astrophysics Data System (ADS)

Doty, S. E.; Seagrave, R. C.

2000-05-01

When one is exposed to microgravity, fluid which is normally pooled in the lower extremities is redistributed headward and weight bearing bones begin to demineralize due to reduced mechanical stresses. The kidney, which is the primary regulator of body fluid volume and composition, responds to the fluid shift and bone demineralization by increasing the urinary output of water, sodium, and calcium. This research involves developing a mathematical description of how water and electrolytes are internally redistributed and exchanged with the environment during space flight. This model consequently involves kidney function and the associated endocrine system. The model agrees well with actual data, including that a low sodium diet can prevent bone demineralization. Therefore, assumptions made to develop the model are most likely valid. Additionally, various levels of activity are also considered in the model since exercise may help to eliminate some of the undesired effects of space flight such as muscle atrophy and bone demineralization.

Biomechanics Analysis of Pressure Ulcer Using Damaged Interface Model between Bone and Muscle in the Human Buttock

NASA Astrophysics Data System (ADS)

Slamet, Samuel Susanto; Takano, Naoki; Tanabe, Yoshiyuki; Hatano, Asako; Nagasao, Tomohisa

This paper aims at building up a computational procedure to study the bio-mechanism of pressure ulcer using the finite element method. Pressure ulcer is a disease that occurs in the human body after 2 hours of continuous external force. In the very early stage of pressure ulcer, it is found that the tissues inside the body are damaged, even though skin surface looks normal. This study assumes that tension and/or shear strain will cause damage to loose fibril tissue between the bone and muscle and that propagation of damaged area will lead to fatal stage. Analysis was performed using the finite element method by modeling the damaged fibril tissue as a cutout. By varying the loading directions and watching both tensile and shear strains, the risk of fibril tissue damage and propagation of the damaged area is discussed, which may give new insight for the careful nursing for patients, particularly after surgical treatment. It was found that the pressure ulcer could reoccur for a surgical flap treatment. The bone cut and surgical flap surgery is not perfect to prevent the bone-muscle interfacial damage.

Low Bone Density

MedlinePlus

... Bone Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone ... to people with normal bone density. Detecting Low Bone Density A bone density test will determine whether ...

Targeting neuropilin-1 in human leukemia and lymphoma.

PubMed

Karjalainen, Katja; Jaalouk, Diana E; Bueso-Ramos, Carlos E; Zurita, Amado J; Kuniyasu, Akihiko; Eckhardt, Bedrich L; Marini, Frank C; Lichtiger, Benjamin; O'Brien, Susan; Kantarjian, Hagop M; Cortes, Jorge E; Koivunen, Erkki; Arap, Wadih; Pasqualini, Renata

2011-01-20

Targeted drug delivery offers an opportunity for the development of safer and more effective therapies for the treatment of cancer. In this study, we sought to identify short, cell-internalizing peptide ligands that could serve as directive agents for specific drug delivery in hematologic malignancies. By screening of human leukemia cells with a combinatorial phage display peptide library, we isolated a peptide motif, sequence Phe-Phe/Tyr-Any-Leu-Arg-Ser (F(F)/(Y)XLRS), which bound to different leukemia cell lines and to patient-derived bone marrow samples. The motif was internalized through a receptor-mediated pathway, and we next identified the corresponding receptor as the transmembrane glycoprotein neuropilin-1 (NRP-1). Moreover, we observed a potent anti-leukemia cell effect when the targeting motif was synthesized in tandem to the pro-apoptotic sequence (D)(KLAKLAK)₂. Finally, our results confirmed increased expression of NRP-1 in representative human leukemia and lymphoma cell lines and in a panel of bone marrow specimens obtained from patients with acute lymphoblastic leukemia or acute myelogenous leukemia compared with normal bone marrow. These results indicate that NRP-1 could potentially be used as a target for ligand-directed therapy in human leukemias and lymphomas and that the prototype CGFYWLRSC-GG-(D)(KLAKLAK)₂ is a promising drug candidate in this setting.

Normalization of periodontal tissues in osteopetrotic mib mutant rats, treated with CSF-1

NASA Technical Reports Server (NTRS)

Wojtowicz, A.; Yamauchi, M.; Sotowski, R.; Ostrowski, K.

1998-01-01

The osteopetrotic mib mutation in rats causes defects in the skeletal bone tissue in young animals. These defects, i.e. slow bone remodelling, changes in both crystallinity and mineral content, are transient and undergo normalization, even without any treatment in 6-wk-old animals. Treatment with CSF-1 (colony stimulating factor-1) accelerates the normalization process in skeletal bones. The periodontal tissues around the apices of incisors show abnormalities caused by the slow remodelling process of the mandible bone tissue, the deficiency of osteoclasts and their abnormal morphology, as well as the disorganization of periodontal ligament fibres. In contrast to the skeletal tissues, these abnormalities would not undergo spontaneous normalization. Under treatment with colony stimulating factor 1 (CSF-1), the primitive bone trabeculae of mandible are resorbed and the normalization of the number of osteoclasts and their cytology occurs. The organization of the periodontal ligament fibres is partially restored, resembling the histological structure of the normal one.

Bone apatite composition of necrotic trabecular bone in the femoral head of immature piglets.

PubMed

Aruwajoye, Olumide O; Kim, Harry K W; Aswath, Pranesh B

2015-04-01

Ischemic osteonecrosis of the femoral head (IOFH) can lead to excessive resorption of the trabecular bone and collapse of the femoral head as a structure. A well-known mineral component to trabecular bone is hydroxyapatite, which can be present in many forms due to ionic substitution, thus altering chemical composition. Unfortunately, very little is known about the chemical changes to bone apatite following IOFH. We hypothesized that the apatite composition changes in necrotic bone possibly contribute to increased osteoclast resorption and structural collapse of the femoral head. The purpose of this study was to assess the macroscopic and local phosphate composition of actively resorbed necrotic trabecular bone to isolate differences between areas of increased osteoclast resorption and normal bone formation. A piglet model of IOFH was used. Scanning electron microscopy (SEM), histology, X-ray absorbance near edge structure (XANES), and Raman spectroscopy were performed on femoral heads to characterize normal and necrotic trabecular bone. Backscattered SEM, micro-computed tomography and histology showed deformity and active resorption of necrotic bone compared to normal. XANES and Raman spectroscopy obtained from actively resorbed necrotic bone and normal bone showed increased carbonate-to-phosphate content in the necrotic bone. The changes in the apatite composition due to carbonate substitution may play a role in the increased resorption of necrotic bone due to its increase in solubility. Indeed, a better understanding of the apatite composition of necrotic bone could shed light on osteoclast activity and potentially improve therapeutic treatments that target excessive resorption of bone.

Role of Oxidative Damage in Radiation-Induced Bone Loss

NASA Technical Reports Server (NTRS)

Schreurs, Ann-Sofie; Alwood, Joshua S.; Limoli, Charles L.; Globus, Ruth K.

2014-01-01

During prolonged spaceflight, astronauts are exposed to both microgravity and space radiation, and are at risk for increased skeletal fragility due to bone loss. Evidence from rodent experiments demonstrates that both microgravity and ionizing radiation can cause bone loss due to increased bone-resorbing osteoclasts and decreased bone-forming osteoblasts, although the underlying molecular mechanisms for these changes are not fully understood. We hypothesized that excess reactive oxidative species (ROS), produced by conditions that simulate spaceflight, alter the tight balance between osteoclast and osteoblast activities, leading to accelerated skeletal remodeling and culminating in bone loss. To test this, we used the MCAT mouse model; these transgenic mice over-express the human catalase gene targeted to mitochondria, the major organelle contributing free radicals. Catalase is an anti-oxidant that converts reactive species, hydrogen peroxide into water and oxygen. This animal model was selected as it displays extended lifespan, reduced cardiovascular disease and reduced central nervous system radio-sensitivity, consistent with elevated anti-oxidant activity conferred by the transgene. We reasoned that mice overexpressing catalase in mitochondria of osteoblast and osteoclast lineage cells would be protected from the bone loss caused by simulated spaceflight. Over-expression of human catalase localized to mitochondria caused various skeletal phenotypic changes compared to WT mice; this includes greater bone length, decreased cortical bone area and moment of inertia, and indications of altered microarchitecture. These findings indicate mitochondrial ROS are important for normal bone-remodeling and skeletal integrity. Catalase over-expression did not fully protect skeletal tissue from structural decrements caused by simulated spaceflight; however there was significant protection in terms of cellular oxidative damage (MDA levels) to the skeletal tissue. Furthermore, we used an array of countermeasures (Antioxidant diets and injections) to prevent the radiation-induced bone loss, although these did not prevent bone loss, analysis is ongoing to determine if these countermeasure protected radiation-induced damage to other tissues.

Bone metabolism of male rats chronically exposed to cadmium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brzoska, Malgorzata M.; Moniuszko-Jakoniuk, Janina

2005-09-15

Recently, based on a female rat model of human exposure, we have reported that low-level chronic exposure to cadmium (Cd) has an injurious effect on the skeleton. The purpose of the current study was to investigate whether the exposure may also affect bone metabolism in a male rat model and to estimate the gender-related differences in the bone effect of Cd. Young male Wistar rats received drinking water containing 0, 1, 5, or 50 mg Cd/l for 12 months. The bone effect of Cd was evaluated using bone densitometry and biochemical markers of bone turnover. Renal handling of calcium (Ca)more » and phosphate, and serum concentrations of vitamin D metabolites, calcitonin, and parathormone were estimated as well. At treatment with 1 mg Cd/l, corresponding to the low environmental exposure in non-Cd-polluted areas, the bone mineral content (BMC) and density (BMD) at the femur and lumbar spine (L1-L5) and the total skeleton BMD did not differ compared to control. However, from the 6th month of the exposure, the Z score BMD indicated osteopenia in some animals and after 12 months the bone resorption very clearly tended to an increase. The rats' exposure corresponding to human moderate (5 mg Cd/l) and especially relatively high (50 mg Cd/l) exposure dose- and duration-dependently disturbed the processes of bone turnover and bone mass accumulation leading to formation of less dense than normal bone tissue. The effects were accompanied by changes in the serum concentration of calciotropic hormones and disorders in Ca and phosphate metabolism. It can be concluded that low environmental exposure to Cd may be only a subtle risk factor for skeletal demineralization in men. The results together with our previous findings based on an analogous model using female rats give clear evidence that males are less vulnerable to the bone effects of Cd compared to females.« less

Monosodium glutamate-sensitive hypothalamic neurons contribute to the control of bone mass

NASA Technical Reports Server (NTRS)

Elefteriou, Florent; Takeda, Shu; Liu, Xiuyun; Armstrong, Dawna; Karsenty, Gerard

2003-01-01

Using chemical lesioning we previously identified hypothalamic neurons that are required for leptin antiosteogenic function. In the course of these studies we observed that destruction of neurons sensitive to monosodium glutamate (MSG) in arcuate nuclei did not affect bone mass. However MSG treatment leads to hypogonadism, a condition inducing bone loss. Therefore the normal bone mass of MSG-treated mice suggested that MSG-sensitive neurons may be implicated in the control of bone mass. To test this hypothesis we assessed bone resorption and bone formation parameters in MSG-treated mice. We show here that MSG-treated mice display the expected increase in bone resorption and that their normal bone mass is due to a concomitant increase in bone formation. Correction of MSG-induced hypogonadism by physiological doses of estradiol corrected the abnormal bone resorptive activity in MSG-treated mice and uncovered their high bone mass phenotype. Because neuropeptide Y (NPY) is highly expressed in MSG-sensitive neurons we tested whether NPY regulates bone formation. Surprisingly, NPY-deficient mice had a normal bone mass. This study reveals that distinct populations of hypothalamic neurons are involved in the control of bone mass and demonstrates that MSG-sensitive neurons control bone formation in a leptin-independent manner. It also indicates that NPY deficiency does not affect bone mass.

Identification of stable reference genes for gene expression analysis of three-dimensional cultivated human bone marrow-derived mesenchymal stromal cells for bone tissue engineering.

PubMed

Rauh, Juliane; Jacobi, Angela; Stiehler, Maik

2015-02-01

The principles of tissue engineering (TE) are widely used for bone regeneration concepts. Three-dimensional (3D) cultivation of autologous human mesenchymal stromal cells (MSCs) on porous scaffolds is the basic prerequisite to generate newly formed bone tissue. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is a specific and sensitive analytical tool for the measurement of mRNA-levels in cells or tissues. For an accurate quantification of gene expression levels, stably expressed reference genes (RGs) are essential to obtain reliable results. Since the 3D environment can affect a cell's morphology, proliferation, and gene expression profile compared with two-dimensional (2D) cultivation, there is a need to identify robust RGs for the quantification of gene expression. So far, this issue has not been adequately investigated. The aim of this study was to identify the most stably expressed RGs for gene expression analysis of 3D-cultivated human bone marrow-derived MSCs (BM-MSCs). For this, we analyzed the gene expression levels of n=31 RGs in 3D-cultivated human BM-MSCs from six different donors compared with conventional 2D cultivation using qRT-PCR. MSCs isolated from bone marrow aspirates were cultivated on human cancellous bone cube scaffolds for 14 days. Osteogenic differentiation was assessed by cell-specific alkaline phosphatase (ALP) activity and expression of osteogenic marker genes. Expression levels of potential reference and target genes were quantified using commercially available TaqMan(®) assays. mRNA expression stability of RGs was determined by calculating the coefficient of variation (CV) and using the algorithms of geNorm and NormFinder. Using both algorithms, we identified TATA box binding protein (TBP), transferrin receptor (p90, CD71) (TFRC), and hypoxanthine phosphoribosyltransferase 1 (HPRT1) as the most stably expressed RGs in 3D-cultivated BM-MSCs. Notably, genes that are routinely used as RGs, for example, beta actin (ACTB) and ribosomal protein L37a (RPL37A), were among the least stable genes. We recommend the combined use of TBP, TFRC, and HPRT1 for the accurate and robust normalization of qRT-PCR data of 3D-cultivated human BM-MSCs.

Identification of Stable Reference Genes for Gene Expression Analysis of Three-Dimensional Cultivated Human Bone Marrow-Derived Mesenchymal Stromal Cells for Bone Tissue Engineering

PubMed Central

Rauh, Juliane; Jacobi, Angela

2015-01-01

The principles of tissue engineering (TE) are widely used for bone regeneration concepts. Three-dimensional (3D) cultivation of autologous human mesenchymal stromal cells (MSCs) on porous scaffolds is the basic prerequisite to generate newly formed bone tissue. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is a specific and sensitive analytical tool for the measurement of mRNA-levels in cells or tissues. For an accurate quantification of gene expression levels, stably expressed reference genes (RGs) are essential to obtain reliable results. Since the 3D environment can affect a cell's morphology, proliferation, and gene expression profile compared with two-dimensional (2D) cultivation, there is a need to identify robust RGs for the quantification of gene expression. So far, this issue has not been adequately investigated. The aim of this study was to identify the most stably expressed RGs for gene expression analysis of 3D-cultivated human bone marrow-derived MSCs (BM-MSCs). For this, we analyzed the gene expression levels of n=31 RGs in 3D-cultivated human BM-MSCs from six different donors compared with conventional 2D cultivation using qRT-PCR. MSCs isolated from bone marrow aspirates were cultivated on human cancellous bone cube scaffolds for 14 days. Osteogenic differentiation was assessed by cell-specific alkaline phosphatase (ALP) activity and expression of osteogenic marker genes. Expression levels of potential reference and target genes were quantified using commercially available TaqMan® assays. mRNA expression stability of RGs was determined by calculating the coefficient of variation (CV) and using the algorithms of geNorm and NormFinder. Using both algorithms, we identified TATA box binding protein (TBP), transferrin receptor (p90, CD71) (TFRC), and hypoxanthine phosphoribosyltransferase 1 (HPRT1) as the most stably expressed RGs in 3D-cultivated BM-MSCs. Notably, genes that are routinely used as RGs, for example, beta actin (ACTB) and ribosomal protein L37a (RPL37A), were among the least stable genes. We recommend the combined use of TBP, TFRC, and HPRT1 for the accurate and robust normalization of qRT-PCR data of 3D-cultivated human BM-MSCs. PMID:25000821

Calcium orthophosphates

PubMed Central

Dorozhkin, Sergey V.

2011-01-01

The present overview is intended to point the readers’ attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided. PMID:23507744

Multi analytical technique study of human bones from an archaeological discovery.

PubMed

Lachowicz, J I; Palomba, S; Meloni, P; Carboni, M; Sanna, G; Floris, R; Pusceddu, V; Sarigu, M

2017-03-01

In 1953, during the building restoration of San Michele church (Bono, Sardinia, 16th-19th Century), a high number of disarticulated skeletons were recovered. From a group of 412 hip bones, two of these, affected by several pathological lesions, were analysed. The two coxal bones can be referred to the same individual, an adult man. A multi-analytical study, started with the purpose of investigating the bone pathology, was extended to characterize the mineral components of a large representative set of bones from the same ossuary, all attributed to adult men who lived in the region four-two centuries ago. A quantitative ICP-AES analysis for Ca, Fe, Mg, Mn, Na, Pb and Zn was executed, and a chemometric investigation on the results was performed. This approach gave evidence of the effects of diagenesis, allowed some hypothesis of the incidence of the known dietary habits on bone composition, and completely differentiated the pathological bones from those of a normal population on the basis of the mineral composition. Moreover, porosity, crystallinity and FT-IR analysis were conducted on both non- and pathological sample. Copyright © 2016 Elsevier GmbH. All rights reserved.

The regulation and regulatory role of collagenase in bone

NASA Technical Reports Server (NTRS)

Partridge, N. C.; Walling, H. W.; Bloch, S. R.; Omura, T. H.; Chan, P. T.; Pearman, A. T.; Chou, W. Y.

1996-01-01

Interstitial collagenase plays an important role in both the normal and pathological remodeling of collagenous extracellular matrices, including skeletal tissues. The enzyme is a member of the family of matrix metalloproteinases. Only one rodent interstitial collagenase has been found but there are two human enzymes, human collagenase-1 and -3, the latter being the homologue of the rat enzyme. In developing rat and mouse bone, collagenase is expressed by hypertrophic chondrocytes, osteoblasts, and osteocytes, a situation that is replicated in a fracture callus. Cultured osteoblasts derived from neonatal rat calvariae show greater amounts of collagenase transcripts late in differentiation. These levels can be regulated by parathyroid hormone (PTH), retinoic acid, and insulin-like growth factors, as well as the degree of matrix mineralization. Much of the work on collagenase in bone has been derived from studies on the rat osteosarcoma cell line, UMR 106-01. All bone-resorbing agents stimulate these cells to produce collagenase mRNA and protein, with PTH being the most potent stimulator. Determination of secreted levels of collagenase has been difficult because UMR cells, normal rat osteoblasts, and rat fibroblasts possess a scavenger receptor that removes the enzyme from the extracellular space, internalizes and degrades it, thus imposing another level of control. PTH can also regulate the abundance of the receptor as well as the expression and synthesis of the enzyme. Regulation of the collagenase gene by PTH appears to involve the cAMP pathway as well as a primary response gene, possibly Fos, which then contributes to induction of the collagenase gene. The rat collagenase gene contains an activator protein-1 sequence that is necessary for basal expression, but other promoter regions may also participate in PTH regulation. Thus, there are many levels of regulation of collagenase in bone perhaps constraining what would otherwise be a rampant enzyme.

Dietary and Urinary Sulfur can Predict Changes in Bone Metabolism During Space Flight

NASA Technical Reports Server (NTRS)

Zwart, Sara R.; Heer, Martina; Shackelford, Linda; Smith, Scott M.

2015-01-01

Mitigating space flight-induced bone loss is critical for space exploration, and diet can play a major role in this effort. Previous ground-based studies provide evidence that dietary composition can influence bone resorption during bed rest. In this study we examined the role of dietary intake patterns as one factor that can influence bone mineral loss in astronauts during space flight. Crew members were asked to consume, for 4 days at a time, prescribed menus with either a low (0.3-0.6 g/mEq) or high (1.0-1.3 g/mEq) ratio of animal protein to potassium (APro:K). Menus were developed for each crewmember, and were designed to meet both crew preferences and study constraints. Intakes of energy, total protein, calcium, and sodium were held relatively constant between the two diets. The order of the menus was randomized, and crews completed each set (low and high) once before and twice during space flight, for a total of 6 controlled diet sessions. One inflight session and three postflight sessions (R+30, R+180, R+365) monitored typical dietary intake. As of this writing, data are available from 14 crew members. The final three subjects' inflight samples are awaiting return from the International Space Station via Space-X. On the last day of each of the 4-d controlled diet sessions, 24-h urine samples were collected, along with a fasting blood sample on the morning of the 5th day. Preliminary analyses show that urinary excretion of sulfate (normalized to lean body mass) is a significant predictor of urinary n-telopeptide (NTX). Dietary sulfate (normalized to lean body mass) is also a significant predictor of urinary NTX. The results from this study, will be important to better understand diet and bone interrelationships during space flight as well as on Earth. This study was funded by the Human Health Countermeasures Element of the NASA Human Research Program.

Prevalence of Prostate Cancer Metastases after Intravenous Inoculation Provides Clues into the Molecular Basis of Dormancy in the Bone Marrow Microenvironment1

PubMed Central

Jung, Younghun; Shiozawa, Yusuke; Wang, Jingcheng; McGregor, Natalie; Dai, Jinlu; Park, Serk In; Berry, Janice E; Havens, Aaron M; Joseph, Jeena; Kim, Jin Koo; Patel, Lalit; Carmeliet, Peter; Daignault, Stephanie; Keller, Evan T; McCauley, Laurie K; Pienta, Kenneth J; Taichman, Russell S

2012-01-01

Bone is the preferred metastasis site of advanced prostate cancer (PCa). Using an in vivo murine model of human PCa cell metastasis to bone, we noted that the majority of animals that develop skeletal metastasis have either spinal lesions or lesions in the bones of the hindlimb. Much less frequently, lesions develop in the bones of the forelimb. We therefore speculated whether the environment of the forelimb bones is not permissive for the growth of PCa. Consequently, data on tumor prevalence were normalized to account for the number of PCa cells arriving after intravascular injection, marrow cellularity, and number of hematopoietic stem cell niches. None of these factors were able to account for the observed differences in tumor prevalence. An analysis of differential gene and protein levels identified that growth arrest specific-6 (GAS6) levels were significantly greater in the forelimb versus hindlimb bone marrow. When murine RM1 cells were implanted into subcutaneous spaces in immune competent animals, tumor growth in the GAS6-/- animals was greater than in GAS6+/+ wild-type animals. In an osseous environment, the human PC3 cell line grew significantly better in vertebral body transplants (vossicles) derived from GAS6-/- animals than in vossicles derived from GAS6+/+ animals. Together, these data suggest that the differences in tumor prevalence after intravascular inoculation are a useful model to study the molecular basis of tumor dormancy. Importantly, these data suggest that therapeutic manipulation of GAS6 levels may prove useful as a therapy for metastatic disease. PMID:22745589

Rapid and reliable healing of critical size bone defects with genetically modified sheep muscle.

PubMed

Liu, F; Ferreira, E; Porter, R M; Glatt, V; Schinhan, M; Shen, Z; Randolph, M A; Kirker-Head, C A; Wehling, C; Vrahas, M S; Evans, C H; Wells, J W

2015-09-21

Large segmental defects in bone fail to heal and remain a clinical problem. Muscle is highly osteogenic, and preliminary data suggest that autologous muscle tissue expressing bone morphogenetic protein-2 (BMP-2) efficiently heals critical size defects in rats. Translation into possible human clinical trials requires, inter alia, demonstration of efficacy in a large animal, such as the sheep. Scale-up is fraught with numerous biological, anatomical, mechanical and structural variables, which cannot be addressed systematically because of cost and other practical issues. For this reason, we developed a translational model enabling us to isolate the biological question of whether sheep muscle, transduced with adenovirus expressing BMP-2, could heal critical size defects in vivo. Initial experiments in athymic rats noted strong healing in only about one-third of animals because of unexpected immune responses to sheep antigens. For this reason, subsequent experiments were performed with Fischer rats under transient immunosuppression. Such experiments confirmed remarkably rapid and reliable healing of the defects in all rats, with bridging by 2 weeks and remodelling as early as 3-4 weeks, despite BMP-2 production only in nanogram quantities and persisting for only 1-3 weeks. By 8 weeks the healed defects contained well-organised new bone with advanced neo-cortication and abundant marrow. Bone mineral content and mechanical strength were close to normal values. These data demonstrate the utility of this model when adapting this technology for bone healing in sheep, as a prelude to human clinical trials.

Does maximum torque mean optimal pullout strength of screws?

PubMed

Tankard, Sara E; Mears, Simon C; Marsland, Daniel; Langdale, Evan R; Belkoff, Stephen M

2013-04-01

To determine the relationship between insertion torque and pullout strength of 3.5-mm-diameter cortical screws in cadaveric humeri with different bone mineral densities (BMDs). Five pairs of human humeri from each of 3 BMD groups (normal, osteopenic, and osteoporotic) were used. Holes were drilled in each humerus, and maximum insertion torque (T(max)) was measured by tightening a screw until stripping occurred. In the remaining holes, screws were tightened to 50%, 70%, or 90% of the T(max). A servohydraulic testing machine pulled each screw out at 1 mm/s while resulting force and axial displacement were recorded at 10 Hz. The authors checked for an effect of insertion torque (percent T(max)) on pullout strength using a general linearized and latent mixed model (Stata10), controlling for cortical thickness and BMD (T-score). Pullout strength for normal and osteoporotic bone was greatest for screws inserted to 50% T(max) and was significantly greater than that at T(max) but not significantly different from that at 70% or 90% T(max). For osteopenic bone, pullout strength was greatest at 70% peak torque, but it was not significantly different from the pullout strength at the 50% or 90% T(max) levels. Tightening screws beyond 50% T(max) does not increase pullout strength of the screw and may place bone at risk for damage that might result in loss of fixation. Even after adjusting for bone thickness and density, there is no clear relationship between pullout strength and screw torque.

Human physiology in space

NASA Technical Reports Server (NTRS)

Vernikos, J.

1996-01-01

The universality of gravity (1 g) in our daily lives makes it difficult to appreciate its importance in morphology and physiology. Bone and muscle support systems were created, cellular pumps developed, neurons organised and receptors and transducers of gravitational force to biologically relevant signals evolved under 1g gravity. Spaceflight provides the only microgravity environment where systematic experimentation can expand our basic understanding of gravitational physiology and perhaps provide new insights into normal physiology and disease processes. These include the surprising extent of our body's dependence on perceptual information, and understanding the effect and importance of forces generated within the body's weightbearing structures such as muscle and bones. Beyond this exciting prospect is the importance of this work towards opening the solar system for human exploration. Although both appear promising, we are only just beginning to taste what lies ahead.

Immunohistochemical evidence of ubiquitous distribution of the metalloendoprotease insulin-degrading enzyme (IDE; insulysin) in human non-malignant tissues and tumor cell lines.

PubMed

Weirich, Gregor; Mengele, Karin; Yfanti, Christina; Gkazepis, Apostolos; Hellmann, Daniela; Welk, Anita; Giersig, Cecylia; Kuo, Wen-Liang; Rosner, Marsha Rich; Tang, Wei-Jen; Schmitt, Manfred

2008-11-01

Immunohistochemical evidence of ubiquitous distribution of the metalloprotease insulin-degrading enzyme (IDE; insulysin) in human non-malignant tissues and tumor cells is presented. Immunohistochemical staining was performed on a multi-organ tissue microarray (pancreas, lung, kidney, central/peripheral nervous system, liver, breast, placenta, myocardium, striated muscle, bone marrow, thymus, and spleen) and on a cell microarray of 31 tumor cell lines of different origin, as well as trophoblast cells and normal blood lymphocytes and granulocytes. IDE protein was expressed in all the tissues assessed and all the tumor cell lines except for Raji and HL-60. Trophoblast cells and granulocytes, but not normal lymphocytes, were also IDE-positive.

Immunohistochemical evidence for ubiquitous distribution of metalloendoprotease insulin-degrading enzyme (IDE; insulysin) in human non-malignant tissues and tumor cell lines

PubMed Central

Weirich, Gregor; Mengele, Karin; Yfanti, Christina; Gkazepis, Apostolos; Hellmann, Daniela; Welk, Anita; Giersig, Cecylia; Kuo, Wen-Liang; Rosner, Marsha Rich; Tang, Wei-Jen; Schmitt, Manfred

2013-01-01

Immunohistochemical evidence for ubiquitous distribution of metalloprotease insulin-degrading enzyme (IDE; insulysin) in human non-malignant tissues and tumor cells is presented. Immunohistochemical staining was performed on a multi-organ tissue microarray (pancreas, lung, kidney, central/peripheral nervous system, liver, breast, placenta, myocardium, striated muscle, bone marrow, thymus, spleen) and on a cell microarray encompassing 31 tumor cell lines of different origin plus trophoblast cells, and normal blood lymphocytes and granulocytes. IDE protein is expressed by all of the tissues assessed and in all of the tumor cell lines except Raji and HL-60; trophoblast cells and granulocytes but not normal lymphocytes are also IDE-positive. PMID:18783335

Generation of dendritic cells from human bone marrow mononuclear cells: advantages for clinical application in comparison to peripheral blood monocyte derived cells.

PubMed

Bai, L; Feuerer, M; Beckhove, P; Umansky, V; Schirrmacher, V

2002-02-01

Dendritic cells (DCs) currently used for vaccination in clinical studies to induce immunity against malignant cells are normally generated from peripheral blood-derived monocytes. Here we studied conditions for the generation of DCs from unseparated human bone marrow (BM) mononuclear cells and compared them functionally with DCs from blood. The two types of DCs, from bone marrow (BM-DC) and peripheral blood (BL-DC), were generated in parallel from the same normal healthy donors by culturing in serum-free X-VIVO 20 medium containing GM-CSF and IL-4, and then the phenotypes and functions were compared. BM-DC generation occurred in 14 days and involved proliferative expansion from CD34 stem cells and differentiation while BL-DC generation occurred in 7 days from CD14 monocytes and involved only differentiation. A 7- to 25-fold higher number of DCs could be obtained from BM than from blood. BM-DC had similar phenotypes as BL-DC. The capacity to stimulate MLR reactivity in allogeneic T lymphocytes was higher with BM-DC than that with BL-DC. Also, the capacity to stimulate autologous memory T cell responses to tetanus toxoid (TT) or tuberculin (PPD) was higher with BM-DC than with BL-DC. These results suggest that BM-DC as produced here may be a very economic and useful source of professional antigen-presenting cells for anti-tumor immunotherapeutic protocols.

Differential growth factor control of bone formation through osteoprogenitor differentiation.

PubMed

Chaudhary, L R; Hofmeister, A M; Hruska, K A

2004-03-01

The osteogenic factors bone morphogenetic protein (BMP-7), platelet-derived growth factor (PDGF)-BB, and fibroblast growth factor (FGF-2) regulate the recruitment of osteoprogenitor cells and their proliferation and differentiation into mature osteoblasts. However, their mechanisms of action on osteoprogenitor cell growth, differentiation, and bone mineralization remain unclear. Here, we tested the hypothesis that these osteogenic agents were capable of regulating osteoblast differentiation and bone formation in vitro. Normal human bone marrow stromal (HBMS) cells were treated with BMP-7 (40 ng ml(-1)), PDGF-BB (20 ng ml(-1)), FGF-2 (20 ng ml(-1)), or FGF-2 plus BMP-7 for 28 days in a serum-containing medium with 10 mM beta-glycerophosphate and 50 microg ml(-1) ascorbic acid. BMP-7 stimulated a morphological change to cuboidal-shaped cells, increased alkaline phosphatase (ALKP) activity, bone sialoprotein (BSP) gene expression, and alizarin red S positive nodule formation. Hydroxyapatite (HA) crystal deposition in the nodules was demonstrated by Fourier transform infrared (FTIR) spectroscopy only in BMP-7- and dexamethasone (DEX)-treated cells. DEX-treated cells appeared elongated and fibroblast-like compared to BMP-7-treated cells. FGF-2 did not stimulate ALKP, and cell morphology was dystrophic. PDGF-BB had little or no effect on ALKP activity and biomineralization. Alizarin Red S staining of cells and calcium assay indicated that BMP-7, DEX, and FGF-2 enhanced calcium mineral deposition, but FTIR spectroscopic analysis demonstrated no formation of HA similar to human bone in control, PDGF-BB-, and FGF-2-treated samples. Thus, FGF-2 stimulated amorphous octacalcium phosphate mineral deposition that failed to mature into HA. Interestingly, FGF-2 abrogated BMP-7-induced ALKP activity and HA formation. Results demonstrate that BMP-7 was competent as a sole factor in the differentiation of human bone marrow stromal cells to bone-forming osteoblasts confirmed by FTIR examination of mineralized matrix. Other growth factors, PDGF, and FGF-2 were incompetent as sole factors, and FGF-2 inhibited BMP-7-stimulated osteoblast differentiation.

Space flight and bone formation.

PubMed

Doty, St B

2004-12-01

Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.

Space flight and bone formation

NASA Technical Reports Server (NTRS)

Doty, St B.

2004-01-01

Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.

Trabecular bone adaptation to low-magnitude high-frequency loading in microgravity.

PubMed

Torcasio, Antonia; Jähn, Katharina; Van Guyse, Maarten; Spaepen, Pieter; Tami, Andrea E; Vander Sloten, Jos; Stoddart, Martin J; van Lenthe, G Harry

2014-01-01

Exposure to microgravity causes loss of lower body bone mass in some astronauts. Low-magnitude high-frequency loading can stimulate bone formation on earth. Here we hypothesized that low-magnitude high-frequency loading will also stimulate bone formation under microgravity conditions. Two groups of six bovine cancellous bone explants were cultured at microgravity on a Russian Foton-M3 spacecraft and were either loaded dynamically using a sinusoidal curve or experienced only a static load. Comparable reference groups were investigated at normal gravity. Bone structure was assessed by histology, and mechanical competence was quantified using μCT and FE modelling; bone remodelling was assessed by fluorescent labelling and secreted bone turnover markers. Statistical analyses on morphometric parameters and apparent stiffness did not reveal significant differences between the treatment groups. The release of bone formation marker from the groups cultured at normal gravity increased significantly from the first to the second week of the experiment by 90.4% and 82.5% in response to static and dynamic loading, respectively. Bone resorption markers decreased significantly for the groups cultured at microgravity by 7.5% and 8.0% in response to static and dynamic loading, respectively. We found low strain magnitudes to drive bone turnover when applied at high frequency, and this to be valid at normal as well as at microgravity. In conclusion, we found the effect of mechanical loading on trabecular bone to be regulated mainly by an increase of bone formation at normal gravity and by a decrease in bone resorption at microgravity. Additional studies with extended experimental time and increased samples number appear necessary for a further understanding of the anabolic potential of dynamic loading on bone quality and mechanical competence.

What Is Breast in the Bone?

PubMed

Shemanko, Carrie S; Cong, Yingying; Forsyth, Amanda

2016-10-22

The normal developmental program that prolactin generates in the mammary gland is usurped in the cancerous process and can be used out of its normal cellular context at a site of secondary metastasis. Prolactin is a pleiotropic peptide hormone and cytokine that is secreted from the pituitary gland, as well as from normal and cancerous breast cells. Experimental and epidemiologic data suggest that prolactin is associated with mammary gland development, and also the increased risk of breast tumors and metastatic disease in postmenopausal women. Breast cancer spreads to the bone in approximately 70% of cases with advanced breast cancer. Despite treatment, new bone metastases will still occur in 30%-50% of patients. Only 20% of patients with bone metastases survive five years after the diagnosis of bone metastasis. The breast cancer cells in the bone microenvironment release soluble factors that engage osteoclasts and/or osteoblasts and result in bone breakdown. The breakdown of the bone matrix, in turn, enhances the proliferation of the cancer cells, creating a vicious cycle. Recently, it was shown that prolactin accelerated the breast cancer cell-mediated osteoclast differentiation and bone breakdown by the regulation of breast cancer-secreted proteins. Interestingly, prolactin has the potential to affect multiple proteins that are involved in both breast development and likely bone metastasis, as well. Prolactin has normal bone homeostatic roles and, combined with the natural "recycling" of proteins in different tissues that can be used for breast development and function, or in bone function, increases the impact of prolactin signaling in breast cancer bone metastases. Thus, this review will focus on the role of prolactin in breast development, bone homeostasis and in breast cancer to bone metastases, covering the molecular aspects of the vicious cycle.

Human Immune Disorder Arising from Mutation of the α Chain of the Interleukin-2 Receptor

NASA Astrophysics Data System (ADS)

Sharfe, Nigel; Dadi, Harjit K.; Shahar, Michal; Roifman, Chaim M.

1997-04-01

Profound cellular immunodeficiency occurs as the result of mutations in proteins involved in both the differentiation and function of mature lymphoid cells. We describe here a novel human immune aberration arising from a truncation mutation of the interleukin-2 receptor α chain (CD25), a subunit of the tripartite high-affinity receptor for interleukin 2. This immunodeficiency is characterized by decreased numbers of peripheral T cells displaying abnormal proliferation but normal B cell development. Extensive lymphocytic infiltration of tissues, including lung, liver, gut, and bone, is observed, accompanied by tissue atrophy and inflammation. Although mature T cells are present, the absence of CD25 does affect the differentiation of thymocytes. While displaying normal development of CD2, CD3, CD4, and CD8 expression, CD25-deficient cortical thymocytes do not express CD1, and furthermore they fail to normally down-regulate levels of the anti-apoptotic protein bcl-2.

Fetal nasal bone length in the second trimester: comparison between population groups from different ethnic origins.

PubMed

Papasozomenou, Panayiota; Athanasiadis, Apostolos P; Zafrakas, Menelaos; Panteris, Eleftherios; Loufopoulos, Aristoteles; Assimakopoulos, Efstratios; Tarlatzis, Basil C

2016-03-01

To compare normal ranges of ultrasonographically measured fetal nasal bone length in the second trimester between different ethnic groups. A prospective, non-interventional study in order to establish normal ranges of fetal nasal bone length in the second trimester in a Greek population was conducted in 1220 singleton fetuses between 18 completed weeks and 23 weeks and 6 days of gestation. A literature search followed in order to identify similar studies in different population groups. Fetal nasal bone length mean values and percentiles from different population groups were compared. Analysis of measurements in the Greek population showed a linear association, i.e., increasing nasal bone length with increasing gestational age from 5.73 mm at 18 weeks to 7.63 mm at 23 weeks. Eleven studies establishing normal ranges of fetal nasal bone length in the second trimester were identified. Comparison of fetal nasal bone length mean values between the 12 population groups showed statistically significant differences (P<0.0001). Normal ranges of fetal nasal bone length in the second trimester vary significantly between different ethnic groups. Hence, distinct ethnic nomograms of fetal nasal bone length in the second trimester should be used in a given population rather than an international model.

A preliminary study for non-invasive quantification of manganese in human hand bones.

PubMed

Aslam; Pejović-Milić, A; Chettle, D R; McNeill, F E; Pysklywec, M W; Oudyk, J

2008-10-07

Manganese (Mn) is a nutrient essential for regulating neurological and skeletal functions in the human body, but it is also toxic when humans are excessively exposed to Mn. Blood (or serum/plasma) and other body fluids reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive measurement of Mn stored in bone, using in vivo neutron activation analysis. Following feasibility studies, a first pilot study, using neutron activation analysis to measure Mn in the bones of the hand of ten healthy male human subjects, was conducted with the approval of the concerned research ethics boards. The participants of this study had no known history of exposure to Mn. Two volunteers were excluded from this study due to technical problems with their measurements. The inverse variance weighted mean value of Mn/Ca for the participants of this study is 0.12+/-0.68 microg Mn/g Ca which is comparable within uncertainties with the estimated range of 0.16-0.78 microg Mn/g Ca and mean value of 0.63+/-0.30 microg Mn/g Ca derived from cadaver data. It is recommended to investigate the use of the diagnostic technique for in vivo measurements of workers exposed occupationally to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. The technique needs further development to improve the precision of in vivo measurements in the non-exposed population.

A New In Vitro Model of Breast Cancer Metastasis to Bone

DTIC Science & Technology

2010-04-01

excessive cell vacuolization, ruffled cell margins , and increasing rates of cell-surface detachment. Thus, conventional tissue-culture strategies...determined. 3050 DHURJATI ET AL. apoptotic bodies, cytoplasmic vesiculation, and chromatin margination (Fig. 3) and a distinct loss of insoluble ECM...respond abnormally to various hor- mones and cytokines compared to normal, differen- tiated human osteoblasts. In effort to overcome these limitations

Flow cytometric analysis of normal and neoplastic mast cells: role in diagnosis and follow-up of mast cell disease.

PubMed

Escribano, Luis; Garcia Montero, Andres C; Núñez, Rosa; Orfao, Alberto

2006-08-01

Human mast cells (MCs) are directly derived from human pluripotent CD34+ stem and progenitor hematopoietic cells with stem cell factor being a critical growth factor supporting human MC proliferation, differentiation, and survival. Because of the advantages that flow cytometry offers (it allows rapid, objective, and sensitive multiparameter analysis of high numbers of cells from a sample, with information being provided on the basis of a single cell), it has become the method of choice in the past decade for immunophenotypic identification, enumeration, and characterization of human MCs in bone marrow and other tissue specimens.

Deletion of ameloblastin exon 6 is associated with amelogenesis imperfecta

PubMed Central

Poulter, James A.; Murillo, Gina; Brookes, Steven J.; Smith, Claire E. L.; Parry, David A.; Silva, Sandra; Kirkham, Jennifer; Inglehearn, Chris F.; Mighell, Alan J.

2014-01-01

Amelogenesis imperfecta (AI) describes a heterogeneous group of inherited dental enamel defects reflecting failure of normal amelogenesis. Ameloblastin (AMBN) is the second most abundant enamel matrix protein expressed during amelogenesis. The pivotal role of AMBN in amelogenesis has been confirmed experimentally using mouse models. However, no AMBN mutations have been associated with human AI. Using autozygosity mapping and exome sequencing, we identified genomic deletion of AMBN exon 6 in a second cousin consanguineous family with three of the six children having hypoplastic AI. The genomic deletion corresponds to an in-frame deletion of 79 amino acids, shortening the protein from 447 to 368 residues. Exfoliated primary teeth (unmatched to genotype) were available from family members. The most severely affected had thin, aprismatic enamel (similar to that reported in mice homozygous for Ambn lacking exons 5 and 6). Other teeth exhibited thicker but largely aprismatic enamel. One tooth had apparently normal enamel. It has been suggested that AMBN may function in bone development. No clinically obvious bone or other co-segregating health problems were identified in the family investigated. This study confirms for the first time that AMBN mutations cause non-syndromic human AI and that mouse models with disrupted Ambn function are valid. PMID:24858907

Alteration of blood clot structures by interleukin-1 beta in association with bone defects healing

PubMed Central

Wang, Xin; Friis, Thor E.; Masci, Paul P.; Crawford, Ross W.; Liao, Wenbo; Xiao, Yin

2016-01-01

The quality of hematomas are crucial for successful early bone defect healing, as the structure of fibrin clots can significantly influence the infiltration of cells, necessary for bone regeneration, from adjacent tissues into the fibrin network. This study investigated if there were structural differences between hematomas from normal and delayed healing bone defects and whether such differences were linked to changes in the expression of IL-1β. Using a bone defect model in rats, we found that the hematomas in the delayed healing model had thinner fibers and denser clot structures. Moreover, IL-1β protein levels were significantly higher in the delayed healing hematomas. The effects of IL-1β on the structural properties of human whole blood clots were evaluated by thrombelastograph (TEG), scanning electronic microscopy (SEM), compressive study, and thrombolytic assays. S-nitrosoglutathione (GSNO) was applied to modulate de novo hematoma structure and the impact on bone healing was evaluated in the delayed healing model. We found that GSNO produced more porous hematomas with thicker fibers and resulted in significantly enhanced bone healing. This study demonstrated that IL-1β and GSNO had opposing effects on clot architecture, the structure of which plays a pivotal role in early bone healing. PMID:27767056

Morphological assessment of bone mineralization in tibial metaphyses of ascorbic acid-deficient ODS rats.

PubMed

Hasegawa, Tomoka; Li, Minqi; Hara, Kuniko; Sasaki, Muneteru; Tabata, Chihiro; de Freitas, Paulo Henrique Luiz; Hongo, Hiromi; Suzuki, Reiko; Kobayashi, Masatoshi; Inoue, Kiichiro; Yamamoto, Tsuneyuki; Oohata, Noboru; Oda, Kimimitsu; Akiyama, Yasuhiro; Amizuka, Norio

2011-08-01

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization: while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from these mineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

Bone mineral density in human immunodeficiency virus-1 infected men with hypogonadism prior to highly-active-antiretroviral-therapy (HAART)

PubMed Central

2009-01-01

Alterations of bone metabolism have been observed in numerous studies of HIV-infected patients. Sex steroids are known to profoundly influence bone mass and bone turnover. Hypogonadism is common in HIV-infection. Therefore, we performed a cross sectional study of 80 male HIV-infected patients without wasting syndrome, and 20 healthy male controls, in whom we analyzed urine and serum samples for both calciotropic hormones and markers of bone metabolism and of endocrine testicular function. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry both in the lumbar spine and Ward's triangle of the left hip. None of the patients received highly-active-antiretroviral-therapy (HAART). Compared to eugonadal HIV-infected patients, subjects with hypogonadism (n = 32; 40%) showed statistically significant decrease of serum osteocalcin (p < 0.05) and elevated urinary excretion of crosslinks (p < 0.05). However, we found 13 and 15, respectively, patients with osteopenia (t-score -1.0 to -2.5 SD below normal) of the lumbar spine. The dissociation between bone formation and resorption and the reduction of of BMD (p < 0.05) is stronger expressed in patients with hypogonadism. Habitual hypogonadism appears to be of additional relevance for bone metabolism of male HIV-positive patients prior to HAART. PMID:19258214

A tissue-engineered humanized xenograft model of human breast cancer metastasis to bone

PubMed Central

Thibaudeau, Laure; Taubenberger, Anna V.; Holzapfel, Boris M.; Quent, Verena M.; Fuehrmann, Tobias; Hesami, Parisa; Brown, Toby D.; Dalton, Paul D.; Power, Carl A.; Hollier, Brett G.; Hutmacher, Dietmar W.

2014-01-01

ABSTRACT The skeleton is a preferred homing site for breast cancer metastasis. To date, treatment options for patients with bone metastases are mostly palliative and the disease is still incurable. Indeed, key mechanisms involved in breast cancer osteotropism are still only partially understood due to the lack of suitable animal models to mimic metastasis of human tumor cells to a human bone microenvironment. In the presented study, we investigate the use of a human tissue-engineered bone construct to develop a humanized xenograft model of breast cancer-induced bone metastasis in a murine host. Primary human osteoblastic cell-seeded melt electrospun scaffolds in combination with recombinant human bone morphogenetic protein 7 were implanted subcutaneously in non-obese diabetic/severe combined immunodeficient mice. The tissue-engineered constructs led to the formation of a morphologically intact ‘organ’ bone incorporating a high amount of mineralized tissue, live osteocytes and bone marrow spaces. The newly formed bone was largely humanized, as indicated by the incorporation of human bone cells and human-derived matrix proteins. After intracardiac injection, the dissemination of luciferase-expressing human breast cancer cell lines to the humanized bone ossicles was detected by bioluminescent imaging. Histological analysis revealed the presence of metastases with clear osteolysis in the newly formed bone. Thus, human tissue-engineered bone constructs can be applied efficiently as a target tissue for human breast cancer cells injected into the blood circulation and replicate the osteolytic phenotype associated with breast cancer-induced bone lesions. In conclusion, we have developed an appropriate model for investigation of species-specific mechanisms of human breast cancer-related bone metastasis in vivo. PMID:24713276

Holographic Determination Of Demineralization Of Bones

NASA Astrophysics Data System (ADS)

Ebbeni, J.; Huybrecht, A.; Orloff, S.

1980-05-01

Patients with osteomalacia often complain of back pain or diffuse peripheral bone aches where a mechanical component warrants closer investigations. In order to study the stress-strain patterns in whole human bones and the influence of the degree of calcification upon these patterns, normal bones are submitted to stress and holographic studies are performed prior to and after demineralization. Interpretation of fringes is delicate because the type of loading must be the same in all the experiments with the same bone. Or the demineralization can change non uniformaly the nature of the osseous inhomogeneous structure and caution must be taken to avoid resulting change namely in momentum. Displacements components must be determined in each face of the bone and the calcul of stresses is made in a first step with assumption of equivalent homogeneous material. The problems arrizing in the machanical behaviour of bones are studied experimentally with the various stress analysis techniques. Among these holographical interferometry proved to be particularly well suited because of its high sensitivity, the rough bone surface needs no preparation and it yields the whole deformation field of the surface. Unfortunately the mechanical comportment of the osseous material depends of many factors and the demineralization namely can change non uniformaly the nature of the inhomogeneous structures like bones and caution must be taken for the interpretation of holographic fringes : because of structural variations in bones, apparently similar types of loading can be different namely by evolution of the position of the neutral axis for momentum. Those phenomena will be analysed in different examples. If estimation of demineralization effect is desired, for instance by measurement of appropriated change in elastic modulus, it is important to know any variation in the loading conditions due to specific changes of the material. The first problem considered concerned the measure of Young's modulus E and Poisson's ration of a tigh-bone or tibia. Small test specimens of constant rectangular section are cut out and submitted to pure bending. Classical double exposure holograms are recorded, with the directions of lighting n1 and observation n2 of the specimen nearly parallel to the normal Oz by use of a mirror. (cfr Figure 1).

The golden ratio of nasal width to nasal bone length.

PubMed

Goynumer, G; Yayla, M; Durukan, B; Wetherilt, L

2011-01-01

To calculate the ratio of fetal nasal width over nasal bone length at 14-39 weeks' gestation in Caucasian women. Fetal nasal bone length and nasal width at 14-39 weeks' gestation were measured in 532 normal fetuses. The mean and standard deviations of fetal nasal bone length, nasal width and their ratio to one another were calculated in normal fetuses according to the gestational age to establish normal values. A positive and linear correlation was detected between the nasal bone length and the gestational week, as between the nasal width and the gestational week. No linear growth pattern was found between the gestational week and the ratio of nasal width to nasal bone length, nearly equal to phi, throughout gestation. The ratio of nasal width to nasal bone length, approximately equal to phi, can be calculated at 14-38 weeks' gestation. This might be useful in evaluating fetal abnormalities.

Moderate chronic kidney disease impairs bone quality in C57Bl/6J mice.

PubMed

Heveran, Chelsea M; Ortega, Alicia M; Cureton, Andrew; Clark, Ryan; Livingston, Eric W; Bateman, Ted A; Levi, Moshe; King, Karen B; Ferguson, Virginia L

2016-05-01

Chronic kidney disease (CKD) increases bone fracture risk. While the causes of bone fragility in CKD are not clear, the disrupted mineral homeostasis inherent to CKD may cause material quality changes to bone tissue. In this study, 11-week-old male C57Bl/6J mice underwent either 5/6th nephrectomy (5/6 Nx) or sham surgeries. Mice were fed a normal chow diet and euthanized 11weeks post-surgery. Moderate CKD with high bone turnover was established in the 5/6 Nx group as determined through serum chemistry and bone gene expression assays. We compared nanoindentation modulus and mineral volume fraction (assessed through quantitative backscattered scanning electron microscopy) at matched sites in arrays placed on the cortical bone of the tibia mid-diaphysis. Trabecular and cortical bone microarchitecture and whole bone strength were also evaluated. We found that moderate CKD minimally affected bone microarchitecture and did not influence whole bone strength. Meanwhile, bone material quality decreased with CKD; a pattern of altered tissue maturation was observed with 5/6 Nx whereby the newest 60μm of bone tissue adjacent to the periosteal surface had lower indentation modulus and mineral volume fraction than more interior, older bone. The variance of modulus and mineral volume fraction was also altered following 5/6 Nx, implying that tissue-scale heterogeneity may be negatively affected by CKD. The observed lower bone material quality may play a role in the decreased fracture resistance that is clinically associated with human CKD. Copyright © 2016 Elsevier Inc. All rights reserved.

Moderate Chronic Kidney Disease Impairs Bone Quality in C57Bl/6J Mice

PubMed Central

Heveran, Chelsea M.; Ortega, Alicia M.; Cureton, Andrew; Clark, Ryan; Livingston, Eric; Bateman, Ted; Levi, Moshe; King, Karen B.; Ferguson, Virginia L.

2016-01-01

Chronic kidney disease (CKD) increases bone fracture risk. While the causes of bone fragility in CKD are not clear, the disrupted mineral homeostasis inherent to CKD may cause material quality changes to bone tissue. In this study, 11-week old male C57Bl/6J mice underwent either 5/6th nephrectomy (5/6 Nx) or sham procedures. Mice were fed a normal chow diet and euthanized 11 weeks post-surgery. Moderate CKD with high bone turnover was established in the 5/6 Nx group as determined through serum chemistry and bone gene expression assays. We compared nanoindentation modulus and mineral volume fraction (assessed through quantitative backscattered scanning electron microscopy) at matched sites in arrays placed on the cortical bone of the tibia mid-diaphysis. Trabecular and cortical bone microarchitecture (μCT) and whole bone strength were also evaluated. We found that moderate CKD minimally affected bone microarchitecture and did not influence whole bone strength. Meanwhile, bone material quality decreased with CKD; a pattern of altered tissue maturation was observed with 5/6 Nx whereby the newest 60 micrometers of bone tissue adjacent to the periosteal surface had lower indentation modulus and mineral volume fraction than more interior, older bone. The variance of modulus and mineral volume fraction were also altered following 5/6 Nx, implying that tissue-scale heterogeneity may be negatively affected by CKD. The observed lower bone material quality may play a role in the decreased fracture resistance that is clinically associated with human CKD. PMID:26860048

Effect of transforming growth factor beta (TGF-β) receptor I kinase inhibitor on prostate cancer bone growth.

PubMed

Wan, Xinhai; Li, Zhi-Gang; Yingling, Jonathan M; Yang, Jun; Starbuck, Michael W; Ravoori, Murali K; Kundra, Vikas; Vazquez, Elba; Navone, Nora M

2012-03-01

Transforming growth factor beta 1 (TGF-β1) has been implicated in the pathogenesis of prostate cancer (PCa) bone metastasis. In this study, we tested the antitumor efficacy of a selective TGF-β receptor I kinase inhibitor, LY2109761, in preclinical models. The effect of LY2109761 on the growth of MDA PCa 2b and PC-3 human PCa cells and primary mouse osteoblasts (PMOs) was assessed in vitro by measuring radiolabeled thymidine incorporation into DNA. In vivo, the right femurs of male SCID mice were injected with PCa cells. We monitored the tumor burden in control- and LY2109761-treated mice with MRI analysis and the PCa-induced bone response with X-ray and micro-CT analyses. Histologic changes in bone were studied by performing bone histomorphometric evaluations. PCa cells and PMOs expressed TGF-β receptor I. TGF-β1 induced pathway activation (as assessed by induced expression of p-Smad2) and inhibited cell growth in PC-3 cells and PMOs but not in MDA PCa 2b cells. LY2109761 had no effect on PCa cells but induced PMO proliferation in vitro. As expected, LY2109761 reversed the TGF-β1-induced pathway activation and growth inhibition in PC-3 cells and PMOs. In vivo, LY2109761 treatment for 6weeks resulted in increased volume in normal bone and increased osteoblast and osteoclast parameters. In addition, LY2109761 treatment significantly inhibited the growth of MDA PCa 2b and PC-3 in the bone of SCID mice (p<0.05); moreover, it resulted in significantly less bone loss and change in osteoclast-associated parameters in the PC-3 tumor-bearing bones than in the untreated mice. In summary, we report for the first time that targeting TGF-β receptors with LY2109761 can control PCa bone growth while increasing the mass of normal bone. This increased bone mass in nontumorous bone may be a desirable side effect of LY2109761 treatment for men with osteopenia or osteoporosis secondary to androgen-ablation therapy, reinforcing the benefit of effectively controlling PCa growth in bone. Thus, targeting TGF-β receptor I is a valuable intervention in men with advanced PCa. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of transforming growth factor beta (TGF-β) receptor I kinase inhibitor on prostate cancer bone growth

PubMed Central

Wan, Xinhai; Li, Zhi-Gang; Yingling, Jonathan M.; Yang, Jun; Starbuck, Michael W.; Ravoori, Murali K.; Kundra, Vikas; Vazquez, Elba; Navone, Nora M.

2012-01-01

Transforming growth factor beta 1 (TGF-β1) has been implicated in the pathogenesis of prostate cancer (PCa) bone metastasis. In this study, we tested the antitumor efficacy of a selective TGF-β receptor I kinase inhibitor, LY2109761, in preclinical models. The effect of LY2109761 on the growth of MDA PCa 2b and PC-3 human PCa cells and primary mouse osteoblasts (PMOs) was assessed in vitro by measuring radiolabeled thymidine incorporation into DNA. In vivo, the right femurs of male SCID mice were injected with PCa cells. We monitored the tumor burden in control- and LY2109761-treated mice with MRI analysis and the PCa-induced bone response with x-ray and micro-CT analyses. Histologic changes in bone were studied by performing bone histomorphometric evaluations. PCa cells and PMOs expressed TGF-β receptor I. TGF-β1 induced pathway activation (as assessed by induced expression of p-Smad2) and inhibited cell growth in PC-3 cells and PMOs but not in MDA PCa 2b cells. LY2109761 had no effect on PCa cells but induced PMO proliferation in vitro. As expected, LY2109761 reversed the TGF-β1–induced pathway activation and growth inhibition in PC-3 cells and PMOs. In vivo, LY2109761 treatment for 6 weeks resulted in increased volume in normal bone and increased osteoblast and osteoclast parameters. In addition, LY2109761 treatment significantly inhibited the growth of MDA PCa 2b and PC-3 in the bone of SCID mice (p < 0.05); moreover, it resulted in significantly less bone loss and change in osteoclast-associated parameters in the PC-3 tumor–bearing bones than in the untreated mice. In summary, we report for the first time that targeting TGF-β receptors with LY2109761 can control PCa bone growth while increasing the mass of normal bone. This increased bone mass in nontumorous bone may be a desirable side effect of LY2109761 treatment for men with osteopenia or osteoporosis secondary to androgen-ablation therapy, reinforcing the benefit of effectively controlling PCa growth in bone. Thus, targeting TGF-β receptor I is a valuable intervention in men with advanced PCa. PMID:22173053

High fat diet promotes achievement of peak bone mass in young rats.

PubMed

Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T; Mittal, Monika; Chattopadhyay, Naibedya; Wani, Mohan R; Bhat, Manoj Kumar

2014-12-05

The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.

Onlay bone augmentation on mouse calvarial bone using a hydroxyapatite/collagen composite material with total blood or platelet-rich plasma.

PubMed

Ohba, Seigo; Sumita, Yoshinori; Umebayashi, Mayumi; Yoshimura, Hitoshi; Yoshida, Hisato; Matsuda, Shinpei; Kimura, Hideki; Asahina, Izumi; Sano, Kazuo

2016-01-01

The aim of this study was to assess newly formed onlay bone on mouse calvarial bone using a new artificial bone material, a hydroxyapatite/collagen composite, with total blood or platelet-rich plasma. The hydroxyapatite/collagen composite material with normal saline, total blood or platelet-rich plasma was transplanted on mouse calvarial bone. The mice were sacrificed and the specimens were harvested four weeks after surgery. The newly formed bone area was measured on hematoxylin and eosin stained specimens using Image J software. The hydroxyapatite/collagen composite materials with total blood or platelet-rich plasma induced a significantly greater amount of newly formed bone than that with normal saline. Moreover, bone marrow was observed four weeks after surgery in the transplanted materials with total blood or platelet-rich plasma but not with normal saline. However, there were no significant differences in the amount of newly formed bone between materials used with total blood versus platelet-rich plasma. The hydroxyapatite/collagen composite material was valid for onlay bone augmentation and this material should be soaked in total blood or platelet-rich plasma prior to transplantation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Engineering a humanized bone organ model in mice to study bone metastases.

PubMed

Martine, Laure C; Holzapfel, Boris M; McGovern, Jacqui A; Wagner, Ferdinand; Quent, Verena M; Hesami, Parisa; Wunner, Felix M; Vaquette, Cedryck; De-Juan-Pardo, Elena M; Brown, Toby D; Nowlan, Bianca; Wu, Dan Jing; Hutmacher, Cosmo Orlando; Moi, Davide; Oussenko, Tatiana; Piccinini, Elia; Zandstra, Peter W; Mazzieri, Roberta; Lévesque, Jean-Pierre; Dalton, Paul D; Taubenberger, Anna V; Hutmacher, Dietmar W

2017-04-01

Current in vivo models for investigating human primary bone tumors and cancer metastasis to the bone rely on the injection of human cancer cells into the mouse skeleton. This approach does not mimic species-specific mechanisms occurring in human diseases and may preclude successful clinical translation. We have developed a protocol to engineer humanized bone within immunodeficient hosts, which can be adapted to study the interactions between human cancer cells and a humanized bone microenvironment in vivo. A researcher trained in the principles of tissue engineering will be able to execute the protocol and yield study results within 4-6 months. Additive biomanufactured scaffolds seeded and cultured with human bone-forming cells are implanted ectopically in combination with osteogenic factors into mice to generate a physiological bone 'organ', which is partially humanized. The model comprises human bone cells and secreted extracellular matrix (ECM); however, other components of the engineered tissue, such as the vasculature, are of murine origin. The model can be further humanized through the engraftment of human hematopoietic stem cells (HSCs) that can lead to human hematopoiesis within the murine host. The humanized organ bone model has been well characterized and validated and allows dissection of some of the mechanisms of the bone metastatic processes in prostate and breast cancer.

Mathematical simulations of photon interactions using Monte Carlo analysis to evaluate the uncertainty associated with in vivo K X-ray fluorescence measurements of stable lead in bone

NASA Astrophysics Data System (ADS)

Lodwick, Camille J.

This research utilized Monte Carlo N-Particle version 4C (MCNP4C) to simulate K X-ray fluorescent (K XRF) measurements of stable lead in bone. Simulations were performed to investigate the effects that overlying tissue thickness, bone-calcium content, and shape of the calibration standard have on detector response in XRF measurements at the human tibia. Additional simulations of a knee phantom considered uncertainty associated with rotation about the patella during XRF measurements. Simulations tallied the distribution of energy deposited in a high-purity germanium detector originating from collimated 88 keV 109Cd photons in backscatter geometry. Benchmark measurements were performed on simple and anthropometric XRF calibration phantoms of the human leg and knee developed at the University of Cincinnati with materials proven to exhibit radiological characteristics equivalent to human tissue and bone. Initial benchmark comparisons revealed that MCNP4C limits coherent scatter of photons to six inverse angstroms of momentum transfer and a Modified MCNP4C was developed to circumvent the limitation. Subsequent benchmark measurements demonstrated that Modified MCNP4C adequately models photon interactions associated with in vivo K XRF of lead in bone. Further simulations of a simple leg geometry possessing tissue thicknesses from 0 to 10 mm revealed increasing overlying tissue thickness from 5 to 10 mm reduced predicted lead concentrations an average 1.15% per 1 mm increase in tissue thickness (p < 0.0001). An anthropometric leg phantom was mathematically defined in MCNP to more accurately reflect the human form. A simulated one percent increase in calcium content (by mass) of the anthropometric leg phantom's cortical bone demonstrated to significantly reduce the K XRF normalized ratio by 4.5% (p < 0.0001). Comparison of the simple and anthropometric calibration phantoms also suggested that cylindrical calibration standards can underestimate lead content of a human leg up to 4%. The patellar bone structure in which the fluorescent photons originate was found to vary dramatically with measurement angle. The relative contribution of lead signal from the patella declined from 65% to 27% when rotated 30°. However, rotation of the source-detector about the patella from 0 to 45° demonstrated no significant effect on the net K XRF response at the knee.

Vitamin D and Human Health: Lessons from Vitamin D Receptor Null Mice

PubMed Central

Bouillon, Roger; Carmeliet, Geert; Verlinden, Lieve; van Etten, Evelyne; Verstuyf, Annemieke; Luderer, Hilary F.; Lieben, Liesbet; Mathieu, Chantal; Demay, Marie

2008-01-01

The vitamin D endocrine system is essential for calcium and bone homeostasis. The precise mode of action and the full spectrum of activities of the vitamin D hormone, 1,25-dihydroxyvitamin D [1,25-(OH)2D], can now be better evaluated by critical analysis of mice with engineered deletion of the vitamin D receptor (VDR). Absence of a functional VDR or the key activating enzyme, 25-OHD-1α-hydroxylase (CYP27B1), in mice creates a bone and growth plate phenotype that mimics humans with the same congenital disease or severe vitamin D deficiency. The intestine is the key target for the VDR because high calcium intake, or selective VDR rescue in the intestine, restores a normal bone and growth plate phenotype. The VDR is nearly ubiquitously expressed, and almost all cells respond to 1,25-(OH)2D exposure; about 3% of the mouse or human genome is regulated, directly and/or indirectly, by the vitamin D endocrine system, suggesting a more widespread function. VDR-deficient mice, but not vitamin D- or 1α-hydroxylase-deficient mice, and man develop total alopecia, indicating that the function of the VDR and its ligand is not fully overlapping. The immune system of VDR- or vitamin D-deficient mice is grossly normal but shows increased sensitivity to autoimmune diseases such as inflammatory bowel disease or type 1 diabetes after exposure to predisposing factors. VDR-deficient mice do not have a spontaneous increase in cancer but are more prone to oncogene- or chemocarcinogen-induced tumors. They also develop high renin hypertension, cardiac hypertrophy, and increased thrombogenicity. Vitamin D deficiency in humans is associated with increased prevalence of diseases, as predicted by the VDR null phenotype. Prospective vitamin D supplementation studies with multiple noncalcemic endpoints are needed to define the benefits of an optimal vitamin D status. PMID:18694980

A polymorphism in a conserved posttranscriptional regulatory motif alters bone morphogenetic protein 2 (BMP2) RNA:protein interactions.

PubMed

Fritz, David T; Jiang, Shan; Xu, Junwang; Rogers, Melissa B

2006-07-01

The bone morphogenetic protein (BMP)2 gene has been genetically linked to osteoporosis and osteoarthritis. We have shown that the 3'-untranslated regions (UTR) of BMP2 genes from mammals to fishes are extraordinarily conserved. This indicates that the BMP2 3'-UTR is under stringent selective pressure. We present evidence that the conserved region is a strong posttranscriptional regulator of BMP2 expression. Polymorphisms in cis-regulatory elements have been proven to influence susceptibility to a growing number of diseases. A common single nucleotide polymorphism (SNP) disrupts a putative posttranscriptional regulatory motif, an AU-rich element, within the BMP2 3'-UTR. The affinity of specific proteins for the rs15705 SNP sequence differs from their affinity for the normal human sequence. More importantly, the in vitro decay rate of RNAs with the SNP is higher than that of RNAs with the normal sequence. Such changes in mRNA:protein interactions may influence the posttranscriptional mechanisms that control BMP2 gene expression. The consequent alterations in BMP2 protein levels may influence the development or physiology of bone or other BMP2-influenced tissues.

Dysosteosclerosis Presents as an “Osteoclast-Poor” Form of Osteopetrosis: Comprehensive Investigation of a 3-Year-Old Girl and Literature Review

PubMed Central

Whyte, Michael P; Wenkert, Deborah; McAlister, William H; Novack, Deborah V; Nenninger, Angie R; Zhang, Xiafang; Huskey, Margaret; Mumm, Steven

2010-01-01

Dysosteosclerosis (DSS), an extremely rare dense bone disease, features short stature and fractures and sometimes optic atrophy, cranial nerve palsy, developmental delay, and failure of tooth eruption in infancy or early childhood consistent with osteopetrosis (OPT). Bone histology during childhood shows unresorbed primary spongiosa from deficient osteoclast action. Additionally, there is remarkable progressive flattening of all vertebrae and, by adolescence, paradoxical metaphyseal osteopenia with thin cortical bone. Reports of consanguinity indicate autosomal recessive inheritance, yet more affected males than females suggest X-linked recessive inheritance. We investigated a nonconsanguineous girl with DSS. Osteosclerosis was discovered at age 7 months. Our studies, spanning ages 11 to 44 months, showed weight at approximately 50th percentile, and length diminishing from approximately 30th percentile to –2.3 SD. Head circumference was +4 SD. The patient had frontal bossing, blue sclera, normal teeth, genu valgum, and unremarkable joints. Radiographs showed orbital and facial sclerosis, basilar thickening, bone-in-bone appearance of the pelvis, sclerotic long bone ends, and fractures of ribs and extremities. Progressive metaphyseal widening occurred as vertebrae changed from ovoid to flattened and became beaked anteriorly. A hemogram was normal. Consistent with OPT, serum parathyroid hormone (PTH) concentrations reflected dietary calcium levels. Serum bone alkaline phosphatase, osteocalcin, and TRACP-5b were subnormal. The iliac crest contained excessive primary spongiosa and no osteoclasts. No mutations were identified in the splice sites or exons for the genes encoding chloride channel 7, T-cell immune regulator 1, OPT-associated transmembrane protein 1, and monocyte colony-stimulating factor (M-CSF) and its receptor C-FMS, ANKH, OPG, RANK, and RANKL. Genomic copy-number microarray was unrevealing. Hence, DSS is a distinctive OPT of unknown etiology featuring osteoclast deficiency during early childhood. How osteopenia follows is an enigma of human skeletal pathobiology. © 2010 American Society for Bone and Mineral Research. PMID:20499338

[Comparative studies on the material performances of natural bone-like apatite from different bone sources].

PubMed

Fan, Xiaoxia; Ren, Haohao; Chen, Shutian; Wang, Guangni; Deng, Tianyu; Chen, Xingtao; Yan, Yonggang

2014-04-01

The compressive strength of the original bone tissue was tested, based on the raw human thigh bone, bovine bone, pig bone and goat bone. The four different bone-like apatites were prepared by calcining the raw bones at 800 degrees C for 8 hours to remove organic components. The comparison of composition and structure of bone-like apatite from different bone sources was carried out with a composition and structure test. The results indicated that the compressive strength of goat bone was similar to that of human thigh bone, reached (135.00 +/- 7.84) MPa; Infrared spectrum (IR), X-ray diffraction (XRD) analysis results showed that the bone-like apatite from goat bone was much closer to the structure and phase composition of bone-like apatite of human bones. Inductively Coupled Plasma (ICP) test results showed that the content of trace elements of bone-like apatite from goat bone was closer to that of apatite of human bone. Energy Dispersive Spectrometer (EDS) results showed that the Ca/P value of bone-like apatite from goat bone was also close to that of human bone, ranged to 1.73 +/- 0.033. Scanning electron microscopy (SEM) patterns indicated that the macrographs of the apatite from human bone and that of goat bone were much similar to each other. Considering all the results above, it could be concluded that the goat bone-like apatite is much similar to that of human bone. It can be used as a potential natural bioceramic material in terms of material properties.

Current Strategies to Improve the Bioactivity of PEEK

PubMed Central

Ma, Rui; Tang, Tingting

2014-01-01

The synthetic thermoplastic polymer polyetheretherketone (PEEK) is becoming a popular component of clinical orthopedic and spinal applications, but its practical use suffers from several limitations. Although PEEK is biocompatible, chemically stable, radiolucent and has an elastic modulus similar to that of normal human bone, it is biologically inert, preventing good integration with adjacent bone tissues upon implantation. Recent efforts have focused on increasing the bioactivity of PEEK to improve the bone-implant interface. Two main strategies have been used to overcome the inert character of PEEK. One approach is surface modification to activate PEEK through surface treatment alone or in combination with a surface coating. Another strategy is to prepare bioactive PEEK composites by impregnating bioactive materials into PEEK substrate. Researchers believe that modified bioactive PEEK will have a wide range of orthopedic applications. PMID:24686515

Molecular Interaction of Bone Marrow Adipose Tissue with Energy Metabolism.

PubMed

Suchacki, Karla J; Cawthorn, William P

2018-01-01

The last decade has seen a resurgence in the study of bone marrow adipose tissue (BMAT) across diverse fields such as metabolism, haematopoiesis, skeletal biology and cancer. Herein, we review the most recent developments of BMAT research in both humans and rodents, including the distinct nature of BMAT; the autocrine, paracrine and endocrine interactions between BMAT and various tissues, both in physiological and pathological scenarios; how these interactions might impact energy metabolism; and the most recent technological advances to quantify BMAT. Though still dwarfed by research into white and brown adipose tissues, BMAT is now recognised as endocrine organ and is attracting increasing attention from biomedical researchers around the globe. We are beginning to learn the importance of BMAT both within and beyond the bone, allowing us to better appreciate the role of BMAT in normal physiology and disease.

In vivo measurement of bone aluminum in population living in southern Ontario, Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, K.; Aslam,; Pejovic-Milic, A.

The harmful biological effect of excessive aluminum (Al) load in humans has been well documented in the literature. Al stored in bone, for instance due to dialysis treatment or occupational exposure, can interfere with normal bone remodeling leading to osteodystrophy, osteoarthritis, or osteomalacia. On the other hand, the relationship between chronic Al exposure and the risk of Alzheimer's disease remains controversial. In this work, the feasibility of in vivo neutron activation analysis (IVNAA) for measuring Al levels in the human hand bone, using the thermal neutron capture reaction {sup 27}Al(n,{gamma}){sup 28}Al, is reported. This noninvasive diagnostic technique employs a highmore » beam current Tandetron accelerator based neutron source, an irradiation/shielding cavity, a 4{pi} NaI(Tl) detector system, and a new set of hand bone phantoms. The photon spectra of the irradiated phantom closely resemble those collected from the hands of nonexposed healthy subjects. A protocol was developed using the newly developed hand phantoms, which resulted in a minimum detectable limit (MDL) of 0.29 mg Al in the human hand. Using the ratio of Al to Ca as an index of Al levels per unit bone mass, the MDL was determined as 19.5{+-}1.5 {mu}g Al/g Ca, which is within the range of the measured levels of 20-27 {mu}g Al/g Ca[ICRP, Report of the Task Group on Reference Man, Publication 23 (Pergamon, Oxford, 1975)] found in other in vivo and in vitro studies. Following the feasibility studies conducted with phantoms, the diagnostic technique was used to measure Al levels in the hand bones of 20 healthy human subjects. The mean hand bone Al concentration was determined as 27.1{+-}16.1 ({+-}1 SD) {mu}g Al/g Ca. The average standard error (1{sigma}) in the Al/Ca is 14.0 {mu}g Al/g Ca, which corresponds to an average relative error of 50% in the measured levels of Al/Ca. These results were achieved with a dose equivalent of 17.6 mSv to a hand and an effective dose of 14.4 {mu}Sv. This effective dose is approximately half of that received in a chest radiograph examination. It is recommended to investigate the use of the bone Al IVNAA diagnostic technique for in vivo measurements of patients with documented overload of Al in bone.« less

Fluid volume displacement at the oval and round windows with air and bone conduction stimulation.

PubMed

Stenfelt, Stefan; Hato, Naohito; Goode, Richard L

2004-02-01

The fluids in the cochlea are normally considered incompressible, and the fluid volume displacement of the oval window (OW) and the round window (RW) should be equal and of opposite phase. However, other channels, such as the cochlear and vestibular aqueducts, may affect the fluid flow. To test if the OW and RW fluid flows are equal and of opposite phase, the volume displacement was assessed by multiple point measurement at the windows with a laser Doppler vibrometer. This was done during air conduction (AC) stimulation in seven fresh human temporal bones, and with bone conduction (BC) stimulation in eight temporal bones and one human cadaver head. With AC stimulation, the average volume displacement of the two windows is within 3 dB, and the phase difference is close to 180 degrees for the frequency range 0.1 to 10 kHz. With BC stimulation, the average volume displacement difference between the two windows is greater: below 2 kHz, the volume displacement at the RW is 5 to 15 dB greater than at the OW and above 2 kHz more fluid is displaced at the OW. With BC stimulation, lesions at the OW caused only minor changes of the fluid flow at the RW.

Proliferation and osteoblastic differentiation of human bone marrow-derived stromal cells on akermanite-bioactive ceramics.

PubMed

Sun, Hongli; Wu, Chengtie; Dai, Kerong; Chang, Jiang; Tang, Tingting

2006-11-01

In the present study, the effects of a calcium magnesium silicate bioactive ceramic (akermanite) on proliferation and osteoblastic differentiation of human bone marrow stromal cells (hBMSC) have been investigated and compared with the classical ceramic (beta-tricalcium phosphate, beta-TCP). Akermanite and beta-TCP disks were seeded with hBMSC and kept in growth medium or osteogenic medium for 10 days. Proliferation and osteoblastic differentiation were evaluated on day 1, 4, 7 and 10. The data from the Alamar Blue assay and lactic acid production assay showed that hBMSC proliferated more significantly on akermanite than on beta-TCP. The analysis of osteoblast-related genes, including alkaline phosphatase (ALP), osteopontin (OPN), bone sialoprotein (BSP) and osteocalcin (OC), indicated that akermanite ceramics enhanced the expression of osteoblast-related genes, but type I collagen (COL I) showed no noticeable difference among akermanite and beta-TCP ceramics. Furthermore, this stimulatory effect was observed not only in osteogenic medium, but also in normal growth medium without osteogenic reagents such as l-ascorbic acid, glycerophosphate and dexamethasone. This result suggests that akermanite can promote osteoblastic differentiation of hBMSC in vitro even without osteogenic reagents, and may be used as a bioactive material for bone regeneration and tissue engineering applications.

Fluid volume displacement at the oval and round windows with air and bone conduction stimulation

NASA Astrophysics Data System (ADS)

Stenfelt, Stefan; Hato, Naohito; Goode, Richard L.

2004-02-01

The fluids in the cochlea are normally considered incompressible, and the fluid volume displacement of the oval window (OW) and the round window (RW) should be equal and of opposite phase. However, other channels, such as the cochlear and vestibular aqueducts, may affect the fluid flow. To test if the OW and RW fluid flows are equal and of opposite phase, the volume displacement was assessed by multiple point measurement at the windows with a laser Doppler vibrometer. This was done during air conduction (AC) stimulation in seven fresh human temporal bones, and with bone conduction (BC) stimulation in eight temporal bones and one human cadaver head. With AC stimulation, the average volume displacement of the two windows is within 3 dB, and the phase difference is close to 180° for the frequency range 0.1 to 10 kHz. With BC stimulation, the average volume displacement difference between the two windows is greater: below 2 kHz, the volume displacement at the RW is 5 to 15 dB greater than at the OW and above 2 kHz more fluid is displaced at the OW. With BC stimulation, lesions at the OW caused only minor changes of the fluid flow at the RW.

HYPOXIA-ACTIVATED PRO-DRUG TH-302 EXHIBITS POTENT TUMOUR SUPPRESSIVE ACTIVITY AND COOPERATES WITH CHEMOTHERAPY AGAINST OSTEOSARCOMA

PubMed Central

Liapis, Vasilios; Labrinidis, Agatha; Zinonos, Irene; Hay, Shelley; Ponomarev, Vladimir; Panagopoulos, Vasilios; DeNichilo, Mark; Ingman, Wendy; Atkins, Gerald J.; Findlay, David M.; Zannettino, Andrew CW.; Evdokiou, Andreas

2015-01-01

Tumour hypoxia is a major cause of treatment failure for a variety of malignancies. However, tumour hypoxia also offers treatment opportunities, exemplified by the development compounds that target hypoxic regions within tumours. TH-302 is a pro-drug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide (Br-IPM). When TH-302 is delivered to regions of hypoxia, Br-IPM, the DNA cross linking toxin, is released. In this study we assessed the cytotoxic activity of TH-302 against osteosarcoma cells in vitro and evaluated its anticancer efficacy as a single agent, and in combination with doxorubicin, in an orthotopic mouse model of human osteosarcoma (OS). In vitro, TH-302 was potently cytotoxic to osteosarcoma cells selectively under hypoxic conditions, whereas primary normal human osteoblasts were protected. Animals transplanted with OS cells directly into their tibiae and left untreated developed mixed osteolytic/osteosclerotic bone lesions and subsequently developed lung metastases. TH-302 reduced tumor burden in bone and cooperated with doxorubicin to protect bone from osteosarcoma induced bone destruction, while it also reduced lung metastases. TH-302 may therefore be an attractive therapeutic agent with strong activity as a single agent and in combination with chemotherapy against OS. PMID:25444931

Hypoxia-activated pro-drug TH-302 exhibits potent tumor suppressive activity and cooperates with chemotherapy against osteosarcoma.

PubMed

Liapis, Vasilios; Labrinidis, Agatha; Zinonos, Irene; Hay, Shelley; Ponomarev, Vladimir; Panagopoulos, Vasilios; DeNichilo, Mark; Ingman, Wendy; Atkins, Gerald J; Findlay, David M; Zannettino, Andrew C W; Evdokiou, Andreas

2015-02-01

Tumor hypoxia is a major cause of treatment failure for a variety of malignancies. However, tumor hypoxia also offers treatment opportunities, exemplified by the development compounds that target hypoxic regions within tumors. TH-302 is a pro-drug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide (Br-IPM). When TH-302 is delivered to regions of hypoxia, Br-IPM, the DNA cross linking toxin, is released. In this study we assessed the cytotoxic activity of TH-302 against osteosarcoma cells in vitro and evaluated its anticancer efficacy as a single agent, and in combination with doxorubicin, in an orthotopic mouse model of human osteosarcoma (OS). In vitro, TH-302 was potently cytotoxic to osteosarcoma cells selectively under hypoxic conditions, whereas primary normal human osteoblasts were protected. Animals transplanted with OS cells directly into their tibiae and left untreated developed mixed osteolytic/osteosclerotic bone lesions and subsequently developed lung metastases. TH-302 reduced tumor burden in bone and cooperated with doxorubicin to protect bone from osteosarcoma induced bone destruction, while it also reduced lung metastases. TH-302 may therefore be an attractive therapeutic agent with strong activity as a single agent and in combination with chemotherapy against OS. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

Alteration of Wnt5a expression and of the non-canonical Wnt/PCP and Wnt/PKC-Ca2+ pathways in human osteoarthritis osteoblasts

PubMed Central

Martineau, Xavier; Abed, Élie; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Lajeunesse, Daniel

2017-01-01

Objective Clinical and in vitro studies suggest that subchondral bone sclerosis due to abnormal osteoblasts (Ob) is involved in the progression and/or onset of osteoarthritis (OA). Human Ob isolated from sclerotic subchondral OA bone tissue show an altered phenotype, a decreased canonical Wnt/β-catenin signaling pathway (cWnt), and a reduced mineralization in vitro. In addition to the cWnt pathway, at least two non-canonical signaling pathways, the Wnt/PKC and Wnt/PCP pathway have been described. However, there are no reports of either pathway in OA Ob. Here, we studied the two non-canonical pathways in OA Ob and if they influence their phenotype. Methods Human primary subchondral Ob were isolated from the subchondral bone plate of tibial plateaus of OA patients undergoing total knee arthroplasty, or of normal individuals at autopsy. The expression of genes involved in non-canonical Wnt signaling was evaluated by qRT-PCR and their protein production by Western blot analysis. Alkaline phosphatase activity and osteocalcin secretion (OC) were determined with substrate hydrolysis and EIA, respectively. Mineralization levels were evaluated with Alizarin Red Staining, Wnt/PKC and Wnt/PCP pathways by target gene expression and their respective activity using the NFAT and AP-1 luciferase reporter assays. Results OA Ob showed an altered phenotype as illustrated by an increased alkaline phosphatase activity and osteocalcin release compared to normal Ob. The expression of the non-canonical Wnt5a ligand was increased in OA Ob compared to normal. Whereas, the expression of LGR5 was significantly increased in OA Ob compared to normal Ob, the expression of LGR4 was similar. Wnt5a directly stimulated the expression and production of LGR5, contrasting, Wnt5a did not stimulate the expression of LGR4. Wnt5a also stimulated the phosphorylation of both JNK and PKC, as well as the activity of both NFAT and AP-1 transcription factors. The inhibition of Wnt5a expression partially corrects the abnormal mineralization, OC secretion and ALPase activity of OA Ob. Conclusion These data indicate that the alteration of Wnt5a, a non-canonical Wnt signaling activator, is implicated in the modified signalisation and phenotype observed in OA Ob. PMID:28777797

Endothelial cells and hematopoiesis: a light microscopic study of fetal, normal, and pathologic human bone marrow in plastic-embedded sections.

PubMed

Islam, A; Glomski, C; Henderson, E S

1992-07-01

The origin and morphological identity of hematopoietic progenitor cells, as well as their precursor, the pleuripotential hematopoietic stem cell (HSC), has not been established. Our studies of 2 microns sectioned undecalcified plastic-embedded bone marrow (BM) from healthy human fetuses; normal adults; patients with acute myeloblastic leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic granulocytic leukemia (CGL) in various stages (chronic, accelerated, acute blastic phase, and after autografting); and patients recovering from therapy-induced marrow hypoplasia suggest that proliferative hematopoietic zones exist near the endosteum (endosteal marrow) and the vascular endothelium (capillary and sinus-lining endothelium) and a maturational zone distal to these regions. In some of these areas, morphologically recognizable hematopoietic cells were seen and interpreted as emerging and maturing in a sequential progression, suggesting an origin from the endosteal or endothelial progenitors. In other loci, early hematopoietic cells were seen in close contact with the endosteal or vascular endothelial (VE) cells. This latter relationship suggested that these areas of cellular contact were important and represented sites of cell to cell interaction that may be associated with the liberation of growth factors by endosteal and endothelial cells and their action on hematopoietic progenitor cells. Following treatment-induced hypoplasia, the endosteal and VE cells were seen to modulate, transform, and migrate into the surrounding empty and edematous marrow space as fibroblasts. Later, as hemopoietic regeneration began, clusters of regenerating hematopoietic cells were seen adjacent to bone trabecule (BT) and near the vascular endothelium. We postulate that endosteal and VE cells are the equivalent of embryonal-stage, undifferentiated mesenchyme and, under the appropriate regulatory influence, are capable of modulation and transformation (differentiation) into stromal (fibroblast-like) cells and precursors of hematopoietic cells in normal (physiologic) and stressed (pathologic) conditions. Recently, human endothelial cells have been shown to express a large number of cell surface antigens in common with hematopoietic (myeloid and lymphoid) cells. It is also possible that, in some situations, the VE cells act to establish a microenvironment and liberate growth factor(s), enabling pleuripotential and progenitor cell differentiation into mature hematopoietic cells adjacent to the vascular endothelium. Indeed, vascular endothelium has been shown to elaborate growth factors that participate in normal hematopoiesis.

Premature chromosome condensation studies in human leukemia. I. Pretreatment characteristics.

PubMed

Hittelman, W N; Broussard, L C; McCredie, K

1979-11-01

The phenomenon of premature chromosome condensation (PCC) was used to compare the bone marrow proliferation characteristics of 163 patients with various forms of leukemia prior to the initiation of new therapy. The proliferative potential index (PPI, or fraction of G1 cells in late G1 phase) and the fraction of cells in S phase was determined and compared to the type of disease and the bone marrow blast infiltrate for each patient. Previously untreated patients with acute leukemia exhibited an average PPI value three times that of normal bone marrow (37.5% for acute myeloblastic leukemia [AML], acute monomyeloblastic leukemia [AMML], or acute promyelocytic leukemia [APML] and 42% for acute lymphocytic leukemia [ALL] or acute undifferentiated leukemia [AUL]). Untreated chronic myelogenous leukemia (CML) patients showed intermediate PPI values (25.2%), whereas CML patients with controlled disease exhibited nearly normal PPI values (14.6%). On the other hand, blastic-phase CML patients exhibited PPI values closer to that observed in patients with acute leukemia (35.4%). Seven patients with chronic lymphocytic leukemia (CLL) exhibited even higher PPI values. No correlations were observed between PPI values, fraction of cells in S phase, and marrow blast infiltrate. For untreated acute disease patients, PPI values were prognostic for response only at low and high PPI values. These results suggest that the PCC-determined proliferative potential is a biologic reflection of the degree of malignancy within the bone marrow.

Characterization of distinct classes of differential gene expression in osteoblast cultures from non-syndromic craniosynostosis bone.

PubMed

Rojas-Peña, Monica L; Olivares-Navarrete, Rene; Hyzy, Sharon; Arafat, Dalia; Schwartz, Zvi; Boyan, Barbara D; Williams, Joseph; Gibson, Greg

2014-01-01

Craniosynostosis, the premature fusion of one or more skull sutures, occurs in approximately 1 in 2500 infants, with the majority of cases non-syndromic and of unknown etiology. Two common reasons proposed for premature suture fusion are abnormal compression forces on the skull and rare genetic abnormalities. Our goal was to evaluate whether different sub-classes of disease can be identified based on total gene expression profiles. RNA-Seq data were obtained from 31 human osteoblast cultures derived from bone biopsy samples collected between 2009 and 2011, representing 23 craniosynostosis fusions and 8 normal cranial bones or long bones. No differentiation between regions of the skull was detected, but variance component analysis of gene expression patterns nevertheless supports transcriptome-based classification of craniosynostosis. Cluster analysis showed 4 distinct groups of samples; 1 predominantly normal and 3 craniosynostosis subtypes. Similar constellations of sub-types were also observed upon re-analysis of a similar dataset of 199 calvarial osteoblast cultures. Annotation of gene function of differentially expressed transcripts strongly implicates physiological differences with respect to cell cycle and cell death, stromal cell differentiation, extracellular matrix (ECM) components, and ribosomal activity. Based on these results, we propose non-syndromic craniosynostosis cases can be classified by differences in their gene expression patterns and that these may provide targets for future clinical intervention.

Characterization of Distinct Classes of Differential Gene Expression in Osteoblast Cultures from Non-Syndromic Craniosynostosis Bone

PubMed Central

Rojas-Peña, Monica L.; Olivares-Navarrete, Rene; Hyzy, Sharon; Arafat, Dalia; Schwartz, Zvi; Boyan, Barbara D.; Williams, Joseph; Gibson, Greg

2014-01-01

Craniosynostosis, the premature fusion of one or more skull sutures, occurs in approximately 1 in 2500 infants, with the majority of cases non-syndromic and of unknown etiology. Two common reasons proposed for premature suture fusion are abnormal compression forces on the skull and rare genetic abnormalities. Our goal was to evaluate whether different sub-classes of disease can be identified based on total gene expression profiles. RNA-Seq data were obtained from 31 human osteoblast cultures derived from bone biopsy samples collected between 2009 and 2011, representing 23 craniosynostosis fusions and 8 normal cranial bones or long bones. No differentiation between regions of the skull was detected, but variance component analysis of gene expression patterns nevertheless supports transcriptome-based classification of craniosynostosis. Cluster analysis showed 4 distinct groups of samples; 1 predominantly normal and 3 craniosynostosis subtypes. Similar constellations of sub-types were also observed upon re-analysis of a similar dataset of 199 calvarial osteoblast cultures. Annotation of gene function of differentially expressed transcripts strongly implicates physiological differences with respect to cell cycle and cell death, stromal cell differentiation, extracellular matrix (ECM) components, and ribosomal activity. Based on these results, we propose non-syndromic craniosynostosis cases can be classified by differences in their gene expression patterns and that these may provide targets for future clinical intervention. PMID:25184005

Differential Intracochlear Sound Pressure Measurements in Normal Human Temporal Bones

NASA Astrophysics Data System (ADS)

Nakajima, Hideko Heidi; Dong, Wei; Olson, Elizabeth S.; Merchant, Saumil N.; Ravicz, Michael E.; Rosowski, John J.

2009-02-01

We present the first simultaneous sound pressure measurements in scala vestibuli and scala tympani of the cochlea in human cadaveric temporal bones. Micro-scale fiberoptic pressure sensors enabled the study of differential sound pressure at the cochlear base. This differential pressure is the input to the cochlear partition, driving cochlear waves and auditory transduction. Results showed that: pressure of scala vestibuli was much greater than scala tympani except at low and high frequencies where scala tympani pressure affects the input to the cochlea; the differential pressure proved to be an excellent measure of normal ossicular transduction of sound (shown to decrease 30-50 dB with ossicular disarticulation, whereas the individual scala pressures were significantly affected by non-ossicular conduction of sound at high frequencies); the middle-ear gain and differential pressure were generally bandpass in frequency dependence; and the middle-ear delay in the human was over twice that of the gerbil. Concurrent stapes velocity measurements allowed determination of the differential impedance across the partition and round-window impedance. The differential impedance was generally resistive, while the round-window impedance was consistent with a compliance in conjunction with distributed inertia and damping. Our techniques can be used to study inner-ear conductive pathologies (e.g., semicircular dehiscence), as well as non-ossicular cochlear stimulation (e.g., round-window stimulation) - situations that cannot be completely quantified by measurements of stapes velocity or scala-vestibuli pressure by themselves.

Glucose-6-phosphate transporter gene therapy corrects metabolic and myeloid abnormalities in glycogen storage disease type Ib mice

PubMed Central

Yiu, Wai Han; Pan, Chi-Jiunn; Allamarvdasht, Mohammad; Kim, So Youn; Chou, Janice Y.

2008-01-01

Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the glucose-6-phosphate transporter (G6PT), an endoplasmic reticulum-associated transmembrane protein that is ubiquitously expressed. GSD-Ib patients suffer from disturbed glucose homeostasis and myeloid dysfunctions. To evaluate the feasibility of gene replacement therapy for GSD-Ib, we have infused adenoviral (Ad) vector containing human G6PT (Ad-hG6PT) into G6PT-deficient (G6PT-/-) mice that manifest symptoms characteristics of the human disorder. Ad-hG6PT-infusion restores significant levels of G6PT mRNA expression in the liver, bone marrow, and spleen and corrects metabolic as well as myeloid abnormalities in G6PT-/- mice. The G6PT-/- mice receiving gene therapy exhibit improved growth; normalized serum profiles for glucose, cholesterol, triglyceride, uric acid, and lactic acid; and reduced hepatic glycogen deposition. The therapy also corrects neutropenia and lowers the elevated serum levels of granulocyte colony stimulating factor. The development of bone and spleen in the infused G6PT-/- mice is improved and accompanied by increased cellularity and normalized myeloid progenitor cell frequencies in both tissues. This effective use of gene therapy to correct metabolic imbalances and myeloid dysfunctions in GSD-Ib mice holds promise for the future of gene therapy in humans. PMID:17006547

Leukemia inhibitory factor: a novel bone-active cytokine.

PubMed

Reid, L R; Lowe, C; Cornish, J; Skinner, S J; Hilton, D J; Willson, T A; Gearing, D P; Martin, T J

1990-03-01

A number of cytokines have been found to be potent regulators of bone resorption and to share the properties originally attributed to osteoclast-activating factor. One such activity, differentiation-inducing factor (DIF, D-factor) from mouse spleen cells, shares a number of biological and biochemical properties with the recently characterized and cloned leukemia inhibitory factor (LIF). We have assessed the effects of recombinant LIF on bone resorption and other parameters in neonatal mouse calvaria. Both recombinant murine and human (h) LIFs stimulated 45Ca release from prelabeled calvaria in a dose-dependent manner. The increase in bone resorption was associated with an increase in the number of osteoclasts per mm2 bone. The osteolytic effect of hLIF were blocked by 10(-7) M indomethacin. hLIF also stimulated incorporation of [3H] thymidine into calvaria, but the dose-response relationship was distinct from that for bone resorption, and this effect was not blocked by indomethacin. Similarly, hLIF increased [3H]phenylalanine incorporation into calvaria, and this was also not inhibited by indomethacin. It is concluded that LIF stimulates bone resorption by a mechanism involving prostaglandin production, but that a distinct mechanism is responsible for its stimulation of DNA and protein synthesis. The primary structure of LIF differs from that of other fully characterized, bone-active cytokines, and it, thus, represents a novel factor which may be involved in the normal regulation of bone cell function.

[Comparation on Haversian system between human and animal bones by imaging analysis].

PubMed

Lu, Hui-Ling; Zheng, Jing; Yao, Ya-Nan; Chen, Sen; Wang, Hui-Pin; Chen, Li-Xian; Guo, Jing-Yuan

2006-04-01

To explore the differences in Haversian system between human and animal bones through imaging analysis and morphology description. Thirty-five slices grinding from human being as well as dog, pig, cow and sheep bones were observed to compare their structure, then were analysed with the researchful microscope. Plexiform bone or oeston band was not found in human bones; There were significant differences in the shape, size, location, density of Haversian system, between human and animal bones. The amount of Haversian lamella and diameter of central canal in human were the biggest; Significant differences in the central canal diameter and total area percentage between human and animal bones were shown by imaging analysis. (1) Plexiform bone and osteon band could be the exclusive index in human bone; (2) There were significant differences in the structure of Haversian system between human and animal bones; (3) The percentage of central canals total area was valuable in species identification through imaging analysis.

Simulation of bone resorption-repair coupling in vitro.

PubMed

Jones, S J; Gray, C; Boyde, A

1994-10-01

In the normal adult human skeleton, new bone formation by osteoblasts restores the contours of bone surfaces following osteoclastic bone resorption, but the evidence for resorption-repair coupling remains circumstantial. To investigate whether sites of prior resorption, more than the surrounding unresorbed surface, attract osteoblasts or stimulate them to proliferate or make new matrix, we developed a simple in vitro system in which resorption-repair coupling occurs. Resorption pits were produced in mammalian dentine or bone slabs by culturing chick bone-derived cells on them for 2-3 days. The chick cells were swept off and the substrata reseeded with rat calvarial osteoblastic cells, which make bone nodules in vitro, for periods of up to 8 weeks. Cell positions and new bone formation were investigated by ordinary light microscopy, fluorescence and reflection confocal laser microscopy, and SEM, in stained and unstained samples. There was no evidence that the osteoblasts were especially attracted to, or influenced by, the sites of resorption in dentine or bone before cell confluence was reached. Bone formation was identified by light microscopy by the accumulation of matrix, staining with alizarin and calcein and by von Kossa's method, and confirmed by scanning electron microscopy (SEM) by using backscattered electron (BSE) and transmitted electron imaging of unembedded samples and BSE imaging of micro-milled embedded material. These new bone patches were located initially in the resorption pits. The model in vitro system may throw new light on the factors that control resorption-repair coupling in the mineralised tissues in vivo.

Changes in biochemical markers after lower limb fractures.

PubMed

Stoffel, Karl; Engler, Hanna; Kuster, Markus; Riesen, Walter

2007-01-01

The bone remodeling sequence after bone fracture changes the concentrations of biochemical bone markers, but the relationships of fracture size and of healing time to changes in biomarkers are unclear. The present pilot study was undertaken to determine the changes found in serum bone markers after plate osteosynthesis of closed distal tibial and malleolar fractures during a study period of 24 weeks. We measured tatrate-resistant acid phosphatase (TRACP 5b), collagen type I C-terminal telopeptide (ICTP), bone-specific alkaline phosphatase (bone ALP), osteocalcin (OC), procollagen type I C-terminal propeptide (PICP), procollagen type III N-terminal propeptide (PIIINP), and human cartilage glycoprotein 39 (YKL-40) in 20 patients with lower limb fractures (10 malleolar, 10 tibia). A physical examination and radiographs were completed to assess evidence of union. All malleolar fractures healed within 6 weeks, whereas 2 tibial fractures did not show complete bone healing after 24 weeks. Changes were comparable but more pronounced in the tibia group, and marker concentrations remained increased at the end of study (bone ALP, 86 vs 74 U/L; OC, 14.9 vs 7.7 microg/L; ICTP: 5.6 vs 3.3 microg/L at day 84 after osteosynthesis, P <0.05 in tibia; 80 vs 70 U/L, 8 vs 5.2 microg/L, and 3.5 vs 3.2 microg/L, respectively, in the malleolar fracture group). In normal bone healing, changes in bone turnover markers were primarily dependent on the fracture size. Delayed tibia fracture healing may involve a disturbance in bone remodeling.

Establishing the 3-D finite element solid model of femurs in partial by volume rendering.

PubMed

Zhang, Yinwang; Zhong, Wuxue; Zhu, Haibo; Chen, Yun; Xu, Lingjun; Zhu, Jianmin

2013-01-01

It remains rare to report three-dimensional (3-D) finite element solid model of femurs in partial by volume rendering method, though several methods of femoral 3-D finite element modeling are already available. We aim to analyze the advantages of the modeling method by establishing the 3-D finite element solid model of femurs in partial by volume rendering. A 3-D finite element model of the normal human femurs, made up of three anatomic structures: cortical bone, cancellous bone and pulp cavity, was constructed followed by pretreatment of the CT original image. Moreover, the finite-element analysis was carried on different material properties, three types of materials given for cortical bone, six assigned for cancellous bone, and single for pulp cavity. The established 3-D finite element of femurs contains three anatomical structures: cortical bone, cancellous bone, and pulp cavity. The compressive stress primarily concentrated in the medial surfaces of femur, especially in the calcar femorale. Compared with whole modeling by volume rendering method, the 3-D finite element solid model created in partial is more real and fit for finite element analysis. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Molecular cloning and chromosomal mapping of bone marrow stromal cell surface gene, BST2, that may be involved in pre-B-cell growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishikawa, Jun; Kaisho, Tsuneyasu; Tomizawa, Hitoshi

1995-04-10

Bone marrow stromal cells regulate B-cell growth and development through their surface molecules and cytokines. In this study, we generated a mAb, RS38, that recognized a novel human membrane protein, BST-2, expressed on bone marrow stromal cell lines and synovial cell lines. We cloned a cDNA encoding BST-2 from a rheumatoid arthritis-derived synovial cell line. BST-2 is a 30- to 36-kDa type II transmembrane protein, consisting of 180 amino acids. The BST-2 gene (HGMW-approved symbol BST2) is located on chromosome 19p13.2. BST-2 is expressed not only on certain bone marrow stromal cell lines but also on various normal tissues, althoughmore » its expression pattern is different from that of another bone marrow stromal cell surface molecule, BST-1. BST-2 surface expression on fibroblast cell lines facilitated the stromal cell-dependent growth of a murine bone marrow-derived pre-B-cell line, DW34. The results suggest that BST-2 may be involved in pre-B-cell growth. 45 refs., 7 figs., 2 tabs.« less

[Treatment of Sudeck's syndrome with human calcitonin].

PubMed

Nuti, R; Vattimo, A; Turchetti, V; Martini, G; Righi, G A

1983-08-26

Human calcitonin (Cibacalcin), at a dose of 0.5 mg daily for 15 days followed by 0.5 mg every other day for 4-6 months, was administered to 11 patients (eight men and three women, aged 36-74 years) with posttraumatic reflex sympathetic dystrophy of the lower limbs (stage I-II). Within one month there was significant lessening of pain, improved mobility and less oedema. Biochemical tests were within normal limits before and after treatment, while the pre-treatment raised bone retention of 99mTc-methylene-diphosphonate and increased blood flow in the affected area became normal during treatment. In nine patients healing occurred in the course of four to six months on treatment, in two patients after more than six months. There were no serious side-effects requiring interruption of treatment. These results indicate that human calcitonin should be tried in the treatment of this condition.

Fabrication of a customized bone scaffold using a homemade medical 3D printer for comminuted fractures

NASA Astrophysics Data System (ADS)

Yoon, Do-Kun; Jung, Joo-Young; Shin, Han-Back; Kim, Moo-Sub; Choe, Bo-Young; Kim, Sunmi; Suh, Tae Suk; Lee, Keum Sil; Xing, Lei

2016-09-01

The purpose of this study was to show a 3D printed reconstruction model of a bone destroyed by a comminuted fracture. After a thoracic limb of a cow with a comminuted fracture was scanned by using computed tomography, a scaffold was designed by using a 3D modeling tool for its reconstruction and fabricated by using a homemade medical 3D printer. The homemade medical 3D printer was designed for medical use. In order to reconstruct the geometry of the destroyed bone, we use the geometry of a similar section (reference geometry) of normal bone in the 3D modeling process. The missing part between the destroyed ridge and the reference geometry was filled with an effective space by using a manual interpolation. Inexpensive materials and free software were used to construct the medical 3D printer system. The fabrication of the scaffold progressed according to the design of reconstructed bone by using this medical 3D printer. The material of the scaffold was biodegradable material, and could be transplanted into the human body. The fabricated scaffold was correctly inserted into the fractured bone in place of the destroyed portion, with good agreement. According to physical stress test results, the performance of printing resolution was 0.1 mm. The average geometrical error of the scaffold was below 0.3 mm. The reconstructed bone by using the fabricated scaffold was able to support the weight of the human body. No process used to obtain the result was complex or required many resources. The methods and results in this study show several possible clinical applications in fields such as orthopedics or oncology without a need to purchase high-price instruments for 3D printing.

Mechanical Unloading of Mouse Bone in Microgravity Significantly Alters Cell Cycle Gene Set Expression

NASA Astrophysics Data System (ADS)

Blaber, Elizabeth; Dvorochkin, Natalya; Almeida, Eduardo; Kaplan, Warren; Burns, Brnedan

2012-07-01

Spaceflight factors, including microgravity and space radiation, have many detrimental short-term effects on human physiology, including muscle and bone degradation, and immune system dysfunction. The long-term progression of these physiological effects is still poorly understood, and a serious concern for long duration spaceflight missions. We hypothesized that some of the degenerative effects of spaceflight may be caused in part by an inability of stem cells to proliferate and differentiate normally resulting in an impairment of tissue regenerative processes. Furthermore, we hypothesized that long-term bone tissue degeneration in space may be mediated by activation of the p53 signaling network resulting in cell cycle arrest and/or apoptosis in osteoprogenitors. In our analyses we found that spaceflight caused significant bone loss in the weight-bearing bones of mice with a 6.3% reduction in bone volume and 11.9% decrease in bone thickness associated with increased osteoclastic activity. Along with this rapid bone loss we also observed alterations in the cell cycle characterized by an increase in the Cdkn1a/p21 cell cycle arrest molecule independent of Trp53. Overexpression of Cdkn1a/p21 was localized to osteoblasts lining the periosteal surface of the femur and chondrocytes in the head of the femur, suggesting an inhibition of proliferation in two key regenerative cell types of the femur in response to spaceflight. Additionally we found overexpression of several matrix degradation molecules including MMP-1a, 3 and 10, of which MMP-10 was localized to osteocytes within the shaft of the femur. This, in conjunction with 40 nm resolution synchrotron nano-Computed Tomography (nano-CT) observations of an increase in osteocyte lacunae cross-sectional area, perimeter and a decrease in circularity indicates a potential role for osteocytic osteolysis in the observed bone degeneration in spaceflight. To further investigate the genetic response of bone to mechanical unloading in spaceflight, we conducted genome wide microarray analysis of total RNA isolated from the mouse pelvis. Specifically, 16 week old mice were subjected to 15 days spaceflight onboard NASA's STS-131 space shuttle mission. The pelvis of the mice was dissected, the bone marrow was flushed and the bones were briefly stored in RNAlater. The pelvii were then homogenized, and RNA was isolated using TRIzol. RNA concentration and quality was measured using a Nanodrop spectrometer, and 0.8% agarose gel electrophoresis. Samples of cDNA were analyzed using an Affymetrix GeneChip\\S Gene 1.0 ST (Sense Target) Array System for Mouse and GenePattern Software. We normalized the ST gene arrays using Robust Multichip Average (RMA) normalization, which summarizes perfectly matched spots on the array through the median polish algorithm, rather than normalizing according to mismatched spots. We also used Limma for statistical analysis, using the BioConductor Limma Library by Gordon Smyth, and differential expression analysis to identify genes with significant changes in expression between the two experimental conditions. Finally we used GSEApreRanked for Gene Set Enrichment Analysis (GSEA), with Kolmogorov-Smirnov style statistics to identify groups of genes that are regulated together using the t-statistics derived from Limma. Preliminary results show that 6,603 genes expressed in pelvic bone had statistically significant alterations in spaceflight compared to ground controls. These prominently included cell cycle arrest molecules p21, and p18, cell survival molecule Crbp1, and cell cycle molecules cyclin D1, and Cdk1. Additionally, GSEA results indicated alterations in molecular targets of cyclin D1 and Cdk4, senescence pathways resulting from abnormal laminin maturation, cell-cell contacts via E-cadherin, and several pathways relating to protein translation and metabolism. In total 111 gene sets out of 2,488, about 4%, showed statistically significant set alterations. These alterations indicate significant impairment of normal cellular function in the mechanically unloaded environment of space and could provide important genetic insight into the observed uncoupling of bone formation and resorption in space.

Enhanced anatomical calibration in human movement analysis.

PubMed

Donati, Marco; Camomilla, Valentina; Vannozzi, Giuseppe; Cappozzo, Aurelio

2007-07-01

The representation of human movement requires knowledge of both movement and morphology of bony segments. The determination of subject-specific morphology data and their registration with movement data is accomplished through an anatomical calibration procedure (calibrated anatomical systems technique: CAST). This paper describes a novel approach to this calibration (UP-CAST) which, as compared with normally used techniques, achieves better repeatability, a shorter application time, and can be effectively performed by non-skilled examiners. Instead of the manual location of prominent bony anatomical landmarks, the description of which is affected by subjective interpretation, a large number of unlabelled points is acquired over prominent parts of the subject's bone, using a wand fitted with markers. A digital model of a template-bone is then submitted to isomorphic deformation and re-orientation to optimally match the above-mentioned points. The locations of anatomical landmarks are automatically made available. The UP-CAST was validated considering the femur as a paradigmatic case. Intra- and inter-examiner repeatability of the identification of anatomical landmarks was assessed both in vivo, using average weight subjects, and on bare bones. Accuracy of the identification was assessed using the anatomical landmark locations manually located on bare bones as reference. The repeatability of this method was markedly higher than that reported in the literature and obtained using the conventional palpation (ranges: 0.9-7.6 mm and 13.4-17.9, respectively). Accuracy resulted, on average, in a maximal error of 11 mm. Results suggest that the principal source of variability resides in the discrepancy between subject's and template bone morphology and not in the inter-examiner differences. The UP-CAST anatomical calibration could be considered a promising alternative to conventional calibration contributing to a more repeatable 3D human movement analysis.

Statistical shape analysis of clavicular cortical bone with applications to the development of mean and boundary shape models.

PubMed

Lu, Yuan-Chiao; Untaroiu, Costin D

2013-09-01

During car collisions, the shoulder belt exposes the occupant's clavicle to large loading conditions which often leads to a bone fracture. To better understand the geometric variability of clavicular cortical bone which may influence its injury tolerance, twenty human clavicles were evaluated using statistical shape analysis. The interior and exterior clavicular cortical bone surfaces were reconstructed from CT-scan images. Registration between one selected template and the remaining 19 clavicle models was conducted to remove translation and rotation differences. The correspondences of landmarks between the models were then established using coordinates and surface normals. Three registration methods were compared: the LM-ICP method; the global method; and the SHREC method. The LM-ICP registration method showed better performance than the global and SHREC registration methods, in terms of compactness, generalization, and specificity. The first four principal components obtained by using the LM-ICP registration method account for 61% and 67% of the overall anatomical variation for the exterior and interior cortical bone shapes, respectively. The length was found to be the most significant variation mode of the human clavicle. The mean and two boundary shape models were created using the four most significant principal components to investigate the size and shape variation of clavicular cortical bone. In the future, boundary shape models could be used to develop probabilistic finite element models which may help to better understand the variability in biomechanical responses and injuries to the clavicle. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Gluteal muscle attachment during proximal femoral reconstruction in a canine model.

PubMed

Pluhar, G Elizabeth; Manley, Paul A; Heiner, John P; Vanderby, Ray; Markel, Mark D

2007-02-01

In this 18 month in vivo canine study we compared three methods of attaching the gluteal muscles to the proximal femur during hip reconstruction with an allograft-prosthesis composite (APC). All three methods are commonly practiced in human hip revision surgery and data on their effectiveness in dogs is directly relevant to human treatment. The methods compared were host gluteal tendon sutured to allograft tendon, host greater trochanter apposed to allograft using a cable grip system, and host cortical bone shells around the allograft secured with cerclage wires. For each method, we assessed changes in allograft-host bone fusion, weight bearing, gluteal muscle mass, and structural properties through qualitative radiography, gait analysis, histology, and biomechanical testing. Hip reconstruction using the WRAP method resulted in the greatest limb use with complete resolution of gluteal muscle atrophy 18 months after surgery. This method yielded a stronger, more stable hip joint that allowed for more normal limb function. These hips had the more rapid rate of bony union at the host bone-allograft junction and little resorption of the graft. The increased limb use and resultant larger gluteal muscle mass conferred to the WRAP hip composites the greatest tensile strength and stiffness when tested 18 months after reconstruction. There was a large amount of new bone formation on the periosteal surface where the WRAP reconstructions had an overlay of live bone that resulted in a more rapid union and increased cortical width at the level of the osteotomy. New bone also penetrated into the allograft a greater distance from the osteotomy in the WRAP group.

The effect of middle ear cavity and superior canal dehiscence on wideband acoustic immittance in fresh human cadaveric specimens

NASA Astrophysics Data System (ADS)

Masud, Salwa F.; Raufer, Stefan; Neely, Stephen T.; Nakajima, Hideko H.

2018-05-01

Superior canal dehiscence (SCD) is a hole in the bony wall of the superior semicircular canal, which can cause various auditory and/or vestibular symptoms and can result in wrong and/or delayed diagnosis. Wideband acoustic immittance (WAI) can potentially distinguish various mechanical middle-ear pathologies as well as inner-ear pathologies non-invasively. We found that in patients, SCD was commonly associated with a narrow-band decrease in power reflectance (PR, derived from WAI) near 1 kHz. Because clinical data has large variation across individual ears and because we do not know the individual "normal" state prior to SCD, we measured WAI in five fresh temporal bone specimens to determine the effects of SCD with respect to the normal state. In temporal bone, we measured PR to assess mechanical changes before and after SCD, as well as to assess the effect of an open or closed middle-ear cavity. After SCD, PR had a consistent decrease between 0.48 and 0.76 kHz, and a slight increase between 1.04 and 1.4 kHz in the open cavity condition. However, in several experiments, we observed low PR around 1 kHz in the normal state before SCD, likely due to the specimen's open middle ear cavity (MEC). Because we see effects of both SCD and open MEC around 1 kHz, some of the SCD effect can be masked by the effect of the MEC in the temporal bone specimens. To compensate for this MEC effect, we estimated the effect of SCD in a closed MEC case, but the effect did not differ significantly from the measured open MEC. This study demonstrates the limitation of temporal bone experiments with open MEC when studying inner-ear lesions with WAI.

Skeletal dysplasia with craniofacial deformity and disproportionate dwarfism in hair sheep of northeastern Brazil.

PubMed

Dantas, F P M; Medeiros, G X; Figueiredo, A P M; Thompson, K; Riet-Correa, F

2014-01-01

This paper reports a newly described form of skeletal dysplasia affecting Brazilian hair sheep of the Cabugi breed. This breed is characterized by having a short head and in some cases the animals are smaller and more compact than sheep of similar breeds. Lambs born with craniofacial abnormalities and dwarfism that die at 2-6 months of age are frequent in this breed. In a flock of 68 ewes and three rams of the Cabugi breed, 134 lambs were born over a 4-year period. Of these, 14 (10.4%) had marked cranial abnormalities and dwarfism and died or were humanely destroyed, 43 (32%) had a normal face and 77 (57.5%) had the short face characteristic of the breed. Dwarf lambs were much smaller than normal, with short legs, a domed head with retruded muzzle and protruded mandible, sternal deformities and exophthalmic eyes situated more laterally in the face than normal. Microscopical examination of long bones of the limbs, bones of the base of the skull and vertebrae showed no lesions. Bones from four affected lambs and one control lamb were macerated for morphometric examination. Although the length of the spinal cord was similar, there was disproportionate shortening of the appendicular bones, particularly the distal segments. Thus the disease was defined as a skeletal dysplasia characterized by craniofacial deformity and disproportionate dwarfism. It is suggested that the disease is inherited as an incomplete dominant trait. The shortened face, which is a feature of the Cabugi breed, may represent the heterozygous state and the more severe, often lethal, dwarfism may occur in homozygotes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Y-90-DOTA-hLL2: An Agent for Radioimmunotherapy of Non-Hodgkin's Lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffiths, Gary L.; Govindan, Serengulam V.; Sharkey, Robert M.

2003-01-01

The goal of this work was to determine an optimal radioimmunotherapy agent for non-Hodgkin's lymphoma. We established the stability profile of yttrium-90-labeled humanized LL2 (hLL2) monoclonal antibody prepared with different chelating agents, and from these data estimated the improvement using the most stable yttrium-90 chelate-hLL2 complex. Methods: The complementary-determining region- (cdr)-grafted (humanized) anti-CD22 mAb, hLL2 (epratuzumab), was conjugated to derivatives of DTPA and 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). The conjugates were labeled with Y-90 and tested against a 10,000-fold molar excess of free DTPA and against human serum. The conjugates were also labeled with Y-88 and compared for biodistribution in normal andmore » lymphoma xenograft-bearing athymic mice. In vivo data were analyzed for uptake of yttrium in bone and washed bone when either the DOTA or the Mx-DTPA chelates were used, and dosimetry calculations were made for each. Results: Y-90-DOTA -mAb were stable to either DTPA or serum challenge. DTPA complexes of hLL2 lost 3-4% of Y-90 (days 1-4) and 10-15% thereafter. In vivo, stability differences showed lower Y-90 uptake in bone using DOTA. Absorbed doses per 37 MBq (1 mCi) Y-90-mAb were 3555 and 5405 cGy for bone, and 2664 and 4524 cGy for washed-bone for 90Y-DOTA-hLL2 and 90Y-MxDTPA-hLL2, respectively, amounting to 52% and 69.8% increases in absorbed radiation doses for bone and washed-bone when switching from a DOTA to a Mx-DTPA chelate. Conclusion: Y-90-hLL2 prepared with the DOTA chelate represents a preferred agent for RAIT of non-Hodgkin's lymphoma, with an in vivo model demonstrating a large reduction in bone-deposited yttrium, as compared to yttrium-90-hLL2 agents prepared with open-chain DTPA-type chelating agents. Dosimetry suggests that this will result in a substantial toxicological advantage for a DOTA-based hLL2 conjugate.« less

In vivo nuclear magnetic resonance imaging

NASA Technical Reports Server (NTRS)

Leblanc, A.; Evans, H.; Bryan, R. N.; Johnson, P.; Schonfeld, E.; Jhingran, S. G.

1984-01-01

A number of physiological changes have been demonstrated in bone, muscle and blood after exposure of humans and animals to microgravity. Determining mechanisms and the development of effective countermeasures for long duration space missions is an important NASA goal. The advent of tomographic nuclear magnetic resonance imaging (NMR or MRI) gives NASA a way to greatly extend early studies of this phenomena in ways not previously possible; NMR is also noninvasive and safe. NMR provides both superb anatomical images for volume assessments of individual organs and quantification of chemical/physical changes induced in the examined tissues. The feasibility of NMR as a tool for human physiological research as it is affected by microgravity is demonstrated. The animal studies employed the rear limb suspended rat as a model of mucle atrophy that results from microgravity. And bedrest of normal male subjects was used to simulate the effects of microgravity on bone and muscle.

MERP1: a mammalian ependymin-related protein gene differentially expressed in hematopoietic cells.

PubMed

Gregorio-King, Claudia C; McLeod, Janet L; Collier, Fiona McL; Collier, Gregory R; Bolton, Karyn A; Van Der Meer, Gavin J; Apostolopoulos, Jim; Kirkland, Mark A

2002-03-20

We have utilized differential display polymerase chain reaction to investigate the gene expression of hematopoietic progenitor cells from adult bone marrow and umbilical cord blood. A differentially expressed gene was identified in CD34+ hematopoietic progenitor cells, with low expression in CD34- cells. We have obtained the full coding sequence of this gene which we designated human mammalian ependymin-related protein 1 (MERP1). Expression of MERP1 was found in a variety of normal human tissues, and is 4- and 10-fold higher in adult bone marrow and umbilical cord blood CD34+ cells, respectively, compared to CD34- cells. Additionally, MERP1 expression in a hematopoietic stem cell enriched population was down-regulated with proliferation and differentiation. Conceptual translation of the MERP1 open reading frame reveals significant homology to two families of glycoprotein calcium-dependant cell adhesion molecules: ependymins and protocadherins.

Additively manufactured porous tantalum implants.

PubMed

Wauthle, Ruben; van der Stok, Johan; Amin Yavari, Saber; Van Humbeeck, Jan; Kruth, Jean-Pierre; Zadpoor, Amir Abbas; Weinans, Harrie; Mulier, Michiel; Schrooten, Jan

2015-03-01

The medical device industry's interest in open porous, metallic biomaterials has increased in response to additive manufacturing techniques enabling the production of complex shapes that cannot be produced with conventional techniques. Tantalum is an important metal for medical devices because of its good biocompatibility. In this study selective laser melting technology was used for the first time to manufacture highly porous pure tantalum implants with fully interconnected open pores. The architecture of the porous structure in combination with the material properties of tantalum result in mechanical properties close to those of human bone and allow for bone ingrowth. The bone regeneration performance of the porous tantalum was evaluated in vivo using an orthotopic load-bearing bone defect model in the rat femur. After 12 weeks, substantial bone ingrowth, good quality of the regenerated bone and a strong, functional implant-bone interface connection were observed. Compared to identical porous Ti-6Al-4V structures, laser-melted tantalum shows excellent osteoconductive properties, has a higher normalized fatigue strength and allows for more plastic deformation due to its high ductility. It is therefore concluded that this is a first step towards a new generation of open porous tantalum implants manufactured using selective laser melting. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Computational assessment of press-fit acetabular implant fixation: the effect of implant design, interference fit, bone quality, and frictional properties.

PubMed

Janssen, D; Zwartelé, R E; Doets, H C; Verdonschot, N

2010-01-01

Patients suffering from rheumatoid arthritis typically have a poor subchondral bone quality, endangering implant fixation. Using finite element analysis (FEA) an investigation was made to find whether a press-fit acetabular implant with a polar clearance would reduce interfacial micromotions and improve fixation compared with a standard hemispherical design. In addition, the effects of interference fit, friction, and implant material were analysed. Cups were introduced into an FEA model of a human pelvis with simulated subchondral bone plasticity. The models were loaded with a loading configuration simulating two cycles of normal walking, during which contact stresses and interfacial micromotions were monitored. Subsequently, a lever-out simulation was performed to assess the fixation strength of the various cases. A flattened cup with good bone quality produced the lowest interfacial micromotions. Poor bone decreased the fixation strength regardless of the geometry of the cup. Increasing the interference fit of the flattened cup compensated for the loss of fixation strength caused by poor bone quality. In conclusion, a flattened cup did not significantly improve implant fixation over a hemispherical cup in the case of poor bone quality. However, implant fixation can be optimized by increasing interference fit and avoiding inferior frictional properties and low-stiffness implants.

Glucocorticoid induced osteopenia in cancellous bone of sheep: validation of large animal model for spine fusion and biomaterial research.

PubMed

Ding, Ming; Cheng, Liming; Bollen, Peter; Schwarz, Peter; Overgaard, Søren

2010-02-15

Glucocorticoid with low calcium and phosphorus intake induces osteopenia in cancellous bone of sheep. To validate a large animal model for spine fusion and biomaterial research. A variety of ovariectomized animals has been used to study osteoporosis. Most experimental spine fusions were based on normal animals, and there is a great need for suitable large animal models with adequate bone size that closely resemble osteoporosis in humans. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 (GC-1) received prednisolone (GC) treatment (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 (GC-2) received the same treatment as GC-1 for 7 months followed by 3 months without treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium and phosphorus during experiment. After killing the animals, cancellous bone specimens from the vertebra, femurs, and tibias were micro-CT scanned and tested mechanically. Serum biomarkers were determined. In lumbar vertebra, the GC treatment resulted in significant decrease of cancellous bone volume fraction and trabecular thickness, and bone strength. However, the microarchitecture and bone strength of GC-2 recovered to a similar level of the controls. A similar trend of microarchitectural changes was also observed in the distal femur and proximal tibia of both GC treated sheep. The bone formation marker serum-osteocalcin was largely reduced in GC-1 compared to the controls, but recovered with a rebound increase at month 10 in GC-2. The current investigation demonstrates that the changes in microarchitecture and mechanical properties were comparable with those observed in humans after long-term GC treatment. A prolonged GC treatment is needed for a long-term observation to keep osteopenic bone. This model resembles long-term glucocorticoid treated osteoporotic model, and is useful in preclinical studies.

Normal bone and soft tissue distribution of fluorine-18-sodium fluoride and artifacts on 18F-NaF PET/CT bone scan: a pictorial review.

PubMed

Sarikaya, Ismet; Elgazzar, Abdelhamid H; Sarikaya, Ali; Alfeeli, Mahmoud

2017-10-01

Fluorine-18-sodium fluoride (F-NaF) PET/CT is a relatively new and high-resolution bone imaging modality. Since the use of F-NaF PET/CT has been increasing, it is important to accurately assess the images and be aware of normal distribution and major artifacts. In this pictorial review article, we will describe the normal uptake patterns of F-NaF in the bone tissues, particularly in complex structures, as well as its physiologic soft tissue distribution and certain artifacts seen on F-NaF PET/CT images.

Bone growth and turnover in progesterone receptor knockout mice.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda

2008-05-01

The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bonesmore » of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.« less

DLX3 regulates bone mass by targeting genes supporting osteoblast differentiation and mineral homeostasis in vivo

PubMed Central

Isaac, J; Erthal, J; Gordon, J; Duverger, O; Sun, H-W; Lichtler, A C; Stein, G S; Lian, J B; Morasso, M I

2014-01-01

Human mutations and in vitro studies indicate that DLX3 has a crucial function in bone development, however, the in vivo role of DLX3 in endochondral ossification has not been established. Here, we identify DLX3 as a central attenuator of adult bone mass in the appendicular skeleton. Dynamic bone formation, histologic and micro-computed tomography analyses demonstrate that in vivo DLX3 conditional loss of function in mesenchymal cells (Prx1-Cre) and osteoblasts (OCN-Cre) results in increased bone mass accrual observed as early as 2 weeks that remains elevated throughout the lifespan owing to increased osteoblast activity and increased expression of bone matrix genes. Dlx3OCN-conditional knockout mice have more trabeculae that extend deeper in the medullary cavity and thicker cortical bone with an increased mineral apposition rate, decreased bone mineral density and increased cortical porosity. Trabecular TRAP staining and site-specific Q-PCR demonstrated that osteoclastic resorption remained normal on trabecular bone, whereas cortical bone exhibited altered osteoclast patterning on the periosteal surface associated with high Opg/Rankl ratios. Using RNA sequencing and chromatin immunoprecipitation-Seq analyses, we demonstrate that DLX3 regulates transcription factors crucial for bone formation such as Dlx5, Dlx6, Runx2 and Sp7 as well as genes important to mineral deposition (Ibsp, Enpp1, Mepe) and bone turnover (Opg). Furthermore, with the removal of DLX3, we observe increased occupancy of DLX5, as well as increased and earlier occupancy of RUNX2 on the bone-specific osteocalcin promoter. Together, these findings provide novel insight into mechanisms by which DLX3 attenuates bone mass accrual to support bone homeostasis by osteogenic gene pathway regulation. PMID:24948010

Juvenile Swine Surgical Alveolar Cleft Model to Test Novel Autologous Stem Cell Therapies

PubMed Central

Caballero, Montserrat; Morse, Justin C.; Halevi, Alexandra E.; Emodi, Omri; Pharaon, Michael R.; Wood, Jeyhan S.

2015-01-01

Reconstruction of craniofacial congenital bone defects has historically relied on autologous bone grafts. Engineered bone using mesenchymal stem cells from the umbilical cord on electrospun nanomicrofiber scaffolds offers an alternative to current treatments. This preclinical study presents the development of a juvenile swine model with a surgically created maxillary cleft defect for future testing of tissue-engineered implants for bone generation. Five-week-old pigs (n=6) underwent surgically created maxillary (alveolar) defects to determine critical-sized defect and the quality of treatment outcomes with rib, iliac crest cancellous bone, and tissue-engineered scaffolds. Pigs were sacrificed at 1 month. Computed tomography scans were obtained at days 0 and 30, at the time of euthanasia. Histological evaluation was performed on newly formed bone within the surgical defect. A 1 cm surgically created defect healed with no treatment, the 2 cm defect did not heal. A subsequently created 1.7 cm defect, physiologically similar to a congenitally occurring alveolar cleft in humans, from the central incisor to the canine, similarly did not heal. Rib graft treatment did not incorporate into adjacent normal bone; cancellous bone and the tissue-engineered graft healed the critical-sized defect. This work establishes a juvenile swine alveolar cleft model with critical-sized defect approaching 1.7 cm. Both cancellous bone and tissue engineered graft generated bridging bone formation in the surgically created alveolar cleft defect. PMID:25837453

Human endothelial precursor cells express tumor endothelial marker 1/endosialin/CD248.

PubMed

Bagley, Rebecca G; Rouleau, Cecile; St Martin, Thia; Boutin, Paula; Weber, William; Ruzek, Melanie; Honma, Nakayuki; Nacht, Mariana; Shankara, Srinivas; Kataoka, Shiro; Ishida, Isao; Roberts, Bruce L; Teicher, Beverly A

2008-08-01

Angiogenesis occurs during normal physiologic processes as well as under pathologic conditions such as tumor growth. Serial analysis of gene expression profiling revealed genes [tumor endothelial markers (TEM)] that are overexpressed in tumor endothelial cells compared with normal adult endothelial cells. Because blood vessel development of malignant tumors under certain conditions may include endothelial precursor cells (EPC) recruited from bone marrow, we investigated TEM expression in EPC. The expression of TEM1 or endosialin (CD248) and other TEM has been discovered in a population of vascular endothelial growth factor receptor 2+/CD31+/CD45-/VE-cadherin+ EPC derived from human CD133+/CD34+ cells. EPC share some properties with fully differentiated endothelial cells from normal tissue, yet reverse transcription-PCR and flow cytometry reveal that EPC express higher levels of endosialin at the molecular and protein levels. The elevated expression of endosialin in EPC versus mature endothelial cells suggests that endosialin is involved in the earlier stages of tumor angiogenesis. Anti-endosialin antibodies inhibited EPC migration and tube formation in vitro. In vivo, immunohistochemistry indicated that human EPC continued to express endosialin protein in a Matrigel plug angiogenesis assay established in nude mice. Anti-endosialin antibodies delivered systemically at 25 mg/kg were also able to inhibit circulating murine EPC in nude mice bearing s.c. SKNAS tumors. EPC and bone marrow-derived cells have been shown previously to incorporate into malignant blood vessels in some instances, yet they remain controversial in the field. The data presented here on endothelial genes that are up-regulated in tumor vasculature and in EPC support the hypothesis that the angiogenesis process in cancer can involve EPC.

p53-Based Strategy for Protection of Bone Marrow From Y-90 Ibritumomab Tiuxetan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Hang, E-mail: suh3@uthscsa.edu; Ganapathy, Suthakar; Li, Xiaolei

Purpose: The main drawbacks of radioimmunotherapy have been severe hematological toxicity and potential development of myelodysplastic syndrome and secondary leukemia. Activation of p53 follows a major pathway by which normal tissues respond to DNA-damaging agents, such as chemotherapy and radiation therapy, that result in injuries and pathological consequences. This pathway is separate from the tumor suppressor pathway of p53. We have previously reported that use of low-dose arsenic (LDA) temporarily and reversibly suppresses p53 activation, thereby ameliorating normal tissue toxicity from exposure to 5-fluorouracil and X rays. We have also demonstrated that LDA-mediated protection requires functional p53 and thus ismore » selective to normal tissues, as essentially every cancer cell has dysfunctional p53. Here we tested the protective efficacy of LDA for bone marrow tissue against radioimmunotherapy through animal experiments. Methods and Materials: Mice were subjected to LDA pretreatment for 3 days, followed by treatment with Y-90 ibritumomab tiuxetan. Both dose course (10, 25, 50, 100, and 200 μCi) and time course (6, 24, and 72 hours and 1 and 2 weeks) experiments were performed. The response of bone marrow cells to LDA was determined by examining the expression of NFκB, Glut1, and Glut3. Staining with hematoxylin and eosin, γ-H2AX, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was used to examine morphology, DNA damage response, and apoptotic cell populations. Results: Elevated levels of NFκB, Glut1, and Glut3 were observed in bone marrow cells after LDA treatment. Bone marrow damage levels induced by Y-90 ibritumomab tiuxetan were greatly reduced by LDA pretreatment. Consistent with this observation, significantly less DNA damage and fewer apoptotic cells were accumulated after Y-90 ibritumomab tiuxetan treatment in LDA-pretreated mice. Furthermore, in the mouse xenograft model implanted with human Karpas-422 lymphoma cells, LDA pretreatment did not have any detectable effect on either tumor growth or Y-90 ibritumomab tiuxetan (200 μCi)-induced tumor suppression. Conclusions: LDA pretreatment protected bone marrow without compromising tumor control caused by Y-90 ibritumomab tiuxetan.« less

Tibial changes in experimental disuse osteoporosis in the monkey

NASA Technical Reports Server (NTRS)

Young, D. R.; Niklowitz, W. J.; Steele, C. R.

1983-01-01

The mechanical properties and structural changes in the monkey tibia with disuse osteoporosis and during subsequent recovery are investigated. Bone mending stiffness is evaluated in relation to microscopic changes in cortical bone and Norland bone mineral analysis. Restraint in the semireclined position is found to produce regional losses of bone most obviously in the anterior-proximal tibiae. After six months of restraint, the greatest losses of bone mineral in the proximal tibiae range from 23 percent to 31 percent; the largest changes in bone stiffness range from 36 percent to 40 percent. Approximately eight and one-half months of recovery are required to restore the normal bending properties. Even after 15 months of recovery, however, the bone mineral content does not necessarily return to normal levels. Histologically, resorption cavities in cortical bone are seen within one month of restraint; by two and one-half months of restraint there are large resorption cavities subperiosteally, endosteally, and intracortically. After 15 months of recovery, the cortex consists mainly of first-generation haversian systems. After 40 months, the cortex appears normal, with numerous secondary and tertiary generations of haversian systems.

NOTE: A preliminary study for non-invasive quantification of manganese in human hand bones

NASA Astrophysics Data System (ADS)

Aslam; Pejović-Milić, A.; Chettle, D. R.; McNeill, F. E.; Pysklywec, M. W.; Oudyk, J.

2008-10-01

Manganese (Mn) is a nutrient essential for regulating neurological and skeletal functions in the human body, but it is also toxic when humans are excessively exposed to Mn. Blood (or serum/plasma) and other body fluids reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive measurement of Mn stored in bone, using in vivo neutron activation analysis. Following feasibility studies, a first pilot study, using neutron activation analysis to measure Mn in the bones of the hand of ten healthy male human subjects, was conducted with the approval of the concerned research ethics boards. The participants of this study had no known history of exposure to Mn. Two volunteers were excluded from this study due to technical problems with their measurements. The inverse variance weighted mean value of Mn/Ca for the participants of this study is 0.12 ± 0.68 µg Mn/g Ca which is comparable within uncertainties with the estimated range of 0.16 0.78 µg Mn/g Ca and mean value of 0.63 ± 0.30 µg Mn/g Ca derived from cadaver data. It is recommended to investigate the use of the diagnostic technique for in vivo measurements of workers exposed occupationally to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. The technique needs further development to improve the precision of in vivo measurements in the non-exposed population.

Evidence for a Role for Nanoporosity and Pyridinoline Content in Human Mild Osteogenesis Imperfecta.

PubMed

Paschalis, Eleftherios P; Gamsjaeger, Sonja; Fratzl-Zelman, Nadja; Roschger, Paul; Masic, Admir; Brozek, Wolfgang; Hassler, Norbert; Glorieux, Francis H; Rauch, Frank; Klaushofer, Klaus; Fratzl, Peter

2016-05-01

Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous connective tissue disorder characterized by bone fragility that arises from decreased bone mass and abnormalities in bone material quality. OI type I represents the milder form of the disease and according to the original Sillence classification is characterized by minimal skeletal deformities and near-normal stature. Raman microspectroscopy is a vibrational spectroscopic technique that allows the determination of bone material properties in bone biopsy blocks with a spatial resolution of ∼1 µm, as a function of tissue age. In the present study, we used Raman microspectroscopy to evaluate bone material quality in transiliac bone biopsies from children with a mild form of OI, either attributable to collagen haploinsufficiency OI type I (OI-Quant; n = 11) or aberrant collagen structure (OI-Qual; n = 5), as a function of tissue age, and compared it against the previously published values established in a cohort of biopsies from healthy children (n = 54, ages 1 to 23 years). The results indicated significant differences in bone material compositional characteristics between OI-Quant patients and healthy controls, whereas fewer were evident in the OI-Qual patients. Differences in both subgroups of OI compared with healthy children were evident for nanoporosity, mineral maturity/crystallinity as determined by maxima of the v1 PO4 Raman band, and pyridinoline (albeit in different direction) content. These alterations in bone material compositional properties most likely contribute to the bone fragility characterizing this disease. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

Laser Doppler Vibrometry measurements of human cadaveric tympanic membrane vibration

PubMed Central

2013-01-01

Objective To determine the feasibility of measuring tympanic membrane (TM) vibrations at multiple locations on the TM to differentiate normal eardrums from those with associated ossicular pathologies. Design Cadaveric human temporal bone study. Setting Basic science laboratory. Methods A mastoidectomy and facial recess approach was performed on four cadaveric temporal bones to obtain access to the ossicles without disrupting the TM. Ossicles were palpated to ensure normal mobility and an intact ossicular chain. Laser Doppler Vibrometry (LDV) measurements were then taken on all four TMs. LDV measurements were repeated on each TM following stapes footplate fixation, incudo-stapedial joint dislocation, and malleus head fixation. Main outcome measures LDV measurements of TM vibration at the umbo, the lateral process of the malleus, and in each of the four quadrants of the TM. Results The best signal-to-noise ratios were found between 2 and 4 kHz, at the umbo, the anterior superior quadrant, the anterior inferior quadrant, and the posterior inferior quadrant. Since our goal was to assess the ossicular chain, we selected the TM locations closest to the ossicular chain (the umbo and lateral process of the malleus) for further analysis. Differences could be seen between normals and the simulated ossicular pathologies, but values were not statistically significant. Conclusions LDV measurements are technically challenging and require optimization to obtain consistent measurements. This study demonstrates the potential of LDV to differentiate ossicular pathologies behind an intact tympanic membrane. Future studies will further characterize the clinical role of this diagnostic modality. PMID:23663748

Synovial fluid progenitors expressing CD90+ from normal but not osteoarthritic joints undergo chondrogenic differentiation without micro-mass culture.

PubMed

Krawetz, Roman J; Wu, Yiru Elizabeth; Martin, Liam; Rattner, Jerome B; Matyas, John R; Hart, David A

2012-01-01

Mesenchymal progenitor cells (MPCs) can differentiate into osteoblasts, adipocytes, and chondrocytes, and are in part responsible for maintaining tissue integrity. Recently, a progenitor cell population has been found within the synovial fluid that shares many similarities with bone marrow MPCs. These synovial fluid MPCs (sfMPCs) share the ability to differentiate into bone and fat, with a bias for cartilage differentiation. In this study, sfMPCs were isolated from human and canine synovial fluid collected from normal individuals and those with osteoarthritis (human: clinician-diagnosed, canine: experimental) to compare the differentiation potential of CD90+ vs. CD90- sfMPCs, and to determine if CD90 (Thy-1) is a predictive marker of synovial fluid progenitors with chondrogenic capacity in vitro. sfMPCs were derived from synovial fluid from normal and OA knee joints. These cells were induced to differentiate into chondrocytes and analyzed using quantitative PCR, immunofluorescence, and electron microscopy. The CD90+ subpopulation of sfMPCs had increased chondrogenic potential compared to the CD90- population. Furthermore, sfMPCs derived from healthy joints did not require a micro-mass step for efficient chondrogenesis. Whereas sfMPCs from OA synovial fluid retain the ability to undergo chondrogenic differentiation, they require micro-mass culture conditions. Overall, this study has demonstrated an increased chondrogenic potential within the CD90+ fraction of human and canine sfMPCs and that this population of cells derived from healthy normal joints do not require a micro-mass step for efficient chondrogenesis, while sfMPCs obtained from OA knee joints do not differentiate efficiently into chondrocytes without the micro-mass procedure. These results reveal a fundamental shift in the chondrogenic ability of cells isolated from arthritic joint fluids, and we speculate that the mechanism behind this change of cell behavior is exposure to the altered milieu of the OA joint fluid, which will be examined in further studies.

Normalization of cortical bone density in children and adolescents with hyperthyroidism treated with antithyroid medication.

PubMed

Numbenjapon, N; Costin, G; Pitukcheewanont, P

2012-09-01

We assessed bone size and bone density (BD) measurements using computed tomography (CT) in children and adolescents with hyperthyroidism treated with antithyroid medication. We found that cortical BD appeared to improve at 1 year and normalize at 2 years in all tested patients. Our previous study demonstrated that cortical BD in children and adolescents with untreated hyperthyroidism was significantly decreased as compared to age-, sex- and ethnicity-matched healthy controls. The present report evaluated whether attainment of euthyroidism by medical antithyroid treatment was able to improve or normalize cortical BD in these patients. Anthropometrics and three-dimensional CT bone measurements including cross-sectional area (CSA), cortical bone area (CBA) and cortical BD at midshaft of the femur (cortical bone), and CSA and BD of L(1) to L(3) vertebrae (cancellous bone) in 15 children and adolescents after 1- and 2-year treatments with antithyroid medication were reviewed and compared to their pretreatment results. All patients were euthyroid at 1 and 2 years after medical antithyroid treatment. After adjusting for age, height, weight and Tanner stage, a significant increase in cortical BD in all patients (15/15) was found after 1 year of treatment (P < 0.001). Normalization of cortical BD was demonstrated in all tested patients (10/15) after 2 years. There were no significant changes in the other cancellous or cortical bone parameters. Cortical BD was improved at 1 year and normalized at 2 years in hyperthyroid patients rendered euthyroid with antithyroid medication.

Fixation of a split fracture of the lateral tibial plateau with a locking screw plate instead of cannulated screws would allow early weight bearing: a computational exploration.

PubMed

Carrera, Ion; Gelber, Pablo Eduardo; Chary, Gaetan; González-Ballester, Miguel A; Monllau, Juan Carlos; Noailly, Jerome

2016-10-01

To assess, with finite element (FE) calculations, whether immediate weight bearing would be possible after surgical stabilization either with cannulated screws or with a locking plate in a split fracture of the lateral tibial plateau (LTP). A split fracture of the LTP was recreated in a FE model of a human tibia. A three-dimensional FE model geometry of a human femur-tibia system was obtained from the VAKHUM project database, and was built from CT images from a subject with normal bone morphologies and normal alignment. The mesh of the tibia was reconverted into a geometry of NURBS surfaces. A split fracture of the lateral tibial plateau was reproduced by using geometrical data from patient radiographs. A locking screw plate (LP) and a cannulated screw (CS) systems were modelled to virtually reduce the fracture and 80 kg static body-weight was simulated. While the simulated body-weight led to clinically acceptable interfragmentary motion, possible traumatic bone shear stresses were predicted nearby the cannulated screws. With a maximum estimation of about 1.7 MPa maximum bone shear stresses, the Polyax system might ensure more reasonable safety margins. Split fractures of the LTP fixed either with locking screw plate or cannulated screws showed no clinically relevant IFM in a FE model. The locking screw plate showed higher mechanical stability than cannulated screw fixation. The locking screw plate might also allow full or at least partial weight bearing under static posture at time zero.

The murine Bapx1 homeobox gene plays a critical role in embryonic development of the axial skeleton and spleen.

PubMed

Tribioli, C; Lufkin, T

1999-12-01

Our previous studies in both mouse and human identified the Bapx1 homeobox gene, a member of the NK gene family, as one of the earliest markers for prechondrogenic cells that will subsequently undergo mesenchymal condensation, cartilage production and, finally, endochondral bone formation. In addition, Bapx1 is an early developmental marker for splanchnic mesoderm, consistent with a role in visceral mesoderm specification, a function performed by its homologue bagpipe, in Drosophila. The human homologue of Bapx1 has been identified and mapped to 4p16.1, a region containing loci for several skeletal diseases. Bapx1 null mice are affected by a perinatal lethal skeletal dysplasia and asplenia, with severe malformation or absence of specific bones of the vertebral column and cranial bones of mesodermal origin, with the most severely affected skeletal elements corresponding to ventral structures associated with the notochord. We provide evidence that the failure of the formation of skeletal elements in Bapx1 null embryos is a consequence of a failure of cartilage development, as demonstrated by downregulation of several molecular markers required for normal chondroblast differentiation (&agr; 1(II) collagen, Fgfr3, Osf2, Indian hedgehog, Sox9), as well as a chondrocyte-specific alpha1 (II) collagen-lacZ transgene. The cartilage defects are correlated with failed differentiation of the sclerotome at the time when these cells are normally initiating chondrogenesis. Loss of Bapx1 is accompanied by an increase in apoptotic cell death in affected tissues, although cell cycling rates are unaltered.

Relationship between the v2PO4/amide III ratio assessed by Raman spectroscopy and the calcium content measured by quantitative backscattered electron microscopy in healthy human osteonal bone

NASA Astrophysics Data System (ADS)

Roschger, Andreas; Gamsjaeger, Sonja; Hofstetter, Birgit; Masic, Admir; Blouin, Stéphane; Messmer, Phaedra; Berzlanovich, Andrea; Paschalis, Eleftherios P.; Roschger, Paul; Klaushofer, Klaus; Fratzl, Peter

2014-06-01

Raman microspectroscopy and quantitative backscattered electron imaging (qBEI) of bone are powerful tools to investigate bone material properties. Both methods provide information on the degree of bone matrix mineralization. However, a head-to-head comparison of these outcomes from identical bone areas has not been performed to date. In femoral midshaft cross sections of three women, 99 regions (20×20 μ) were selected inside osteons and interstitial bone covering a wide range of matrix mineralization. As the focus of this study was only on regions undergoing secondary mineralization, zones exhibiting a distinct gradient in mineral content close to the mineralization front were excluded. The same regions were measured by both methods. We found a linear correlation (R2=0.75) between mineral/matrix as measured by Raman spectroscopy and the wt. %Mineral/(100-wt. %Mineral) as obtained by qBEI, in good agreement with theoretical estimations. The observed deviations of single values from the linear regression line were determined to reflect biological heterogeneities. The data of this study demonstrate the good correspondence between Raman and qBEI outcomes in describing tissue mineralization. The obtained correlation is likely sensitive to changes in bone tissue composition, providing an approach to detect potential deviations from normal bone.

Eldecalcitol normalizes bone turnover markers regardless of their pre-treatment levels.

PubMed

Shiraki, Masataka; Saito, Hitoshi; Matsumoto, Toshio

2012-09-01

Three-year treatment with eldecalcitol has been shown to improve lumbar and total hip bone mineral density (BMD), decrease bone turnover markers, and lower the incidences of vertebral and wrist fractures in patients with osteoporosis more than with treatment with alfacalcidol under vitamin D repletion. The purpose of this study was to determine whether there was a risk of eldecalcitol causing severely suppressed bone turnover in osteoporosis patients with low pre-treatment levels of bone turnover markers. Post-hoc analysis was conducted on the data from a 3-year, randomized, double-blind, active-comparator, clinical trial of eldecalcitol versus alfacalcidol under vitamin D repletion conducted in Japan. Enrolled patients with baseline measurements of bone turnover markers were stratified into tertiles according to their pre-treatment levels of serum bone-specific alkaline phosphatase, serum procollagen type I N-terminal propeptide, or urinary collagen-N-telopeptide. Eldecalcitol treatment rapidly reduced bone turnover markers, and kept them within the normal range. However, in the patients whose baseline values for bone turnover were low, eldecalcitol treatment did not further reduce bone turnover markers during the 3-year treatment period. Further long-term observation may be required to reach the conclusion. CLINICALTRIALS.GOV NUMBER: NCT00144456. Eldecalcitol normalizes, but does not overly suppress, bone turnover regardless of baseline levels of bone turnover markers. Thus, it is unlikely that eldecalcitol treatment will increase the risk of severely suppressed bone turnover and therefore deterioration of bone quality, at least for a treatment duration of 3 years.

Distribution Characteristics of Air-Bone Gaps – Evidence of Bias in Manual Audiometry

PubMed Central

Margolis, Robert H.; Wilson, Richard H.; Popelka, Gerald R.; Eikelboom, Robert H.; Swanepoel, De Wet; Saly, George L.

2015-01-01

Objective Five databases were mined to examine distributions of air-bone gaps obtained by automated and manual audiometry. Differences in distribution characteristics were examined for evidence of influences unrelated to the audibility of test signals. Design The databases provided air- and bone-conduction thresholds that permitted examination of air-bone gap distributions that were free of ceiling and floor effects. Cases with conductive hearing loss were eliminated based on air-bone gaps, tympanometry, and otoscopy, when available. The analysis is based on 2,378,921 threshold determinations from 721,831 subjects from five databases. Results Automated audiometry produced air-bone gaps that were normally distributed suggesting that air- and bone-conduction thresholds are normally distributed. Manual audiometry produced air-bone gaps that were not normally distributed and show evidence of biasing effects of assumptions of expected results. In one database, the form of the distributions showed evidence of inclusion of conductive hearing losses. Conclusions Thresholds obtained by manual audiometry show tester bias effects from assumptions of the patient’s hearing loss characteristics. Tester bias artificially reduces the variance of bone-conduction thresholds and the resulting air-bone gaps. Because the automated method is free of bias from assumptions of expected results, these distributions are hypothesized to reflect the true variability of air- and bone-conduction thresholds and the resulting air-bone gaps. PMID:26627469

[The replacement therapy of rPTH(1-84) in established rat model of hypothyroidism].

PubMed

Ding, Zhiwei; Li, Tiancheng; Liu, Yuhe; Xiao, Shuifang

2015-12-01

To investigate the replacement therapy of rPTH(1-84) (recombinant human parathyroid hormone (1-84)) to hypothyroidism in established rat model. Rat model of hypothyroidism was established by resecting parathyroids. A total of 30 rats with removal of parathyroids were divided into 6 groups randomly, 5 in each group, and applied respectively with saline injection (negative control group), calcitriol treatment (positive control group) and quadripartite PTH administration with dose of 20, 40, 80 and 160 µg/kg (experimental groups). Saline and rPTH(1-84) were injected subcutaneously daily. Calcitriol was gavaged once a day. Sham-operation was conducted in 5 rats of negative control group. To verify the authenticity of the rat model with hypothyroidism, the serum was insolated centrifugally from rat blood that was obtained from angular vein at specific time to measure calcium and phosphorus concentration. Urine in 12 hours was collected by metabolic cages and the calcium concentration was measured. After 10-week drug treatment, the experiment was terminated and bilateral femoral bone and L2-5 lumbar vertebra were removed from rats. Bone mineral density (BMD)of bilateral femoral bone and lumbar vertebra was analyzed by dual X-ray absorptiometry (DXA). The concentration of bone alkaline phosphatase (BALP) in serum was determined by radioimmunoassay. The rat model with hypothyroidism was obtained by excising parathyroid gland and was verified by monitoring calcium and phosphorus concentration subsequently. Administration of rPTH(1-84) in the dose of 80 or 160 µg/kg made serum calcium and phosphorus back to normal levels, with no significant difference between the doses (P>0.05). The BMD in each group of rats with rPTH(1-84) administration was increased significantly (P<0.05). The levels of urinary calcium and serum BALP in rats of maximum rPTH(1-84) injection group (160 µg/kg) were higher than those of normal control group (P<0.05). The rats treated with calcitriol had normal calcium levels and showed the increase of BMD and phosphorus concentration compared with normal control group (P<0.05). The amount of urinary calcium also exceeded the other groups (P<0.05), but no with significant difference in BMD of bilateral femoral bone and lumbar vertebra between negative control group and normal control group (P>0.05). Calcium and phosphorus return to normal level by administration of rPTH(1-84) in the dose of 80 µg/kg or 160 µg/kg, with increase in BMD. Calcitriol can return the level of calcium to normal and increase BMD, but can not correspondingly decrease the phosphorus concentration and increase the excretion of calcium in urine.

Bone mineral density level by dual energy X-ray absorptiometry in rheumatoid arthritis.

PubMed

Makhdoom, Asadullah; Rahopoto, Muhammad Qasim; Awan, Shazia; Tahir, Syed Muhammad; Memon, Shazia; Siddiqui, Khaleeque Ahmed

2017-01-01

To observe the level of bone mineral density by Dual Energy X-ray Absorptiometry in rheumatoid arthritis patients. The observational study was conducted at Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan, from January 2011 to December 2014. Bone mineral density was measured from the femoral neck, ward's triangle and lumbar spine, in patients 25-55 years of age, who were diagnosed with rheumatoid arthritis. All the cases were assessed for bone mineral density from appendicular as well as axial skeleton. Data was collected through a designed proforma and analysis was performed using SPSS 21. Of the 229 rheumatoid arthritis patients, 33(14.4%) were males. Five (15.1%) males had normal bone density, 14(42.4%) had osteopenia and 14(42.4%) had osteoporosis. Of the 196(85.5%) females, 45(29.9%) had normal bone density, 72 (37.7%) had osteopenia and 79(40.30%) had osteoporosis. Of the 123(53.7%) patients aged 30-50 years, 38(30.9%) had normal bone density, 59(48.0%) had osteopenia, and 26(21.1%) had osteoporosis. Of the 106(46.3%) patients over 50 years, 12(11.3%) had normal bone density, 27 (25.5%) had osteopenia and 67(63.2%) had osteoporosis. Osteoporosis and osteopenia were most common among rheumatoid arthritis patients. Assessment of bone mineral density by Dual Energy X-ray Absorptiometry can lead to quick relief in the clinical symptoms with timely therapy.

Calcium orthophosphates: occurrence, properties, biomineralization, pathological calcification and biomimetic applications.

PubMed

Dorozhkin, Sergey V

2011-01-01

The present overview is intended to point the readers' attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided.

Improvement of thrombocytopenia following bone marrow transplantation by pegylated recombinant human megakaryocyte growth and development factor in mice.

PubMed

Kabaya, K; Shibuya, K; Torii, Y; Nitta, Y; Ida, M; Akahori, H; Kato, T; Kusaka, M; Miyazaki, H

1996-12-01

We examined whether pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is capable of improving thrombocytopenia and promoting thrombopoietic reconstitution following lethal irradiation and bone marrow transplantation (BMT) in mice. Immediately after receiving 10 Gy whole body irradiation (day 0), male C3H/HeN mice were inoculated with 10(6) bone marrow cells obtained from syngeneic mice. Circulating platelet counts decreased to below 4% of the normal counts with a nadir on day 10, and then returned to the normal level on day 28 in the control mice undergoing BMT. Subcutaneous consecutive treatment with PEG-rHuMGDF at doses from 10 to 300 micrograms/kg/day from day 1 for 13 days significantly improved the platelet nadir and promoted platelet recovery. The white blood cell counts and hemoglobin concentration following BMT were not influenced by the PEG-rHuMGDF. PEG-rHuMGDF-injection starting from day 5 did not improve the platelet nadir following BMT. Furthermore, administration with PEG-rHuMGDF on alternate days at 55.7 micrograms/kg/day for 7 days or at an interval of 3 days at 78 micrograms/kg/day for 4 days (twice a week for 2 weeks) had a significant efficacy, but these administration regimens had less efficacy than consecutive administration at 30 micrograms/kg/day for 13 days. The numbers of megakaryocytes and megakaryocyte progenitor cells decreased to 5 and 0.2% of normal level, respectively, in the control mice. Consecutive administration of PEG-rHuMGDF enhanced the recovery of the mean number of these cells compared to those in vehicle-treated mice, although such effects were not statistically significant except for the number of megakaryocyte progenitors on day 12. These results suggest that consecutive treatment with PEG-rHuMGDF beginning from the day after BMT may be effective in improving thrombocytopenia following BMT.

Growth hormone mediates pubertal skeletal development independent of hepatic IGF-1 production.

PubMed

Courtland, Hayden-William; Sun, Hui; Beth-On, Mordechay; Wu, Yingjie; Elis, Sebastien; Rosen, Clifford J; Yakar, Shoshana

2011-04-01

Deficiencies in either growth hormone (GH) or insulin-like growth factor 1 (IGF-1) are associated with reductions in bone size during growth in humans and animal models. Liver-specific IGF-1-deficient (LID) mice, which have 75% reductions in serum IGF-1, were created previously to separate the effects of endocrine (serum) IGF-1 from autocrine/paracrine IGF-1. However, LID mice also have two- to threefold increases in GH, and this may contribute to the observed pubertal skeletal phenotype. To clarify the role of GH in skeletal development under conditions of significantly reduced serum IGF-1 levels (but normal tissue IGF-1 levels), we studied the skeletal response of male LID and control mice to GH inhibition by pegvisomant from 4 to 8 weeks of age. Treatment of LID mice with pegvisomant resulted in significant reductions in body weight, femur length (Le), and femur total area (Tt.Ar), as well as further reductions in serum IGF-1 levels by 8 weeks of age, compared with the mean values of vehicle-treated LID mice. Reductions in both Tt.Ar and Le were proportional after treatment with pegvisomant. On the other hand, the relative amount of cortical tissue formed (RCA) in LID mice treated with pegvisomant was significantly less than that in both vehicle-treated LID and control mice, indicating that antagonizing GH action, either directly (through GH receptor signaling inhibition) or indirectly (through further reductions in serum/tissue IGF-1 levels), results in disproportionate reductions in the amount of cortical bone formed. This resulted in bones with significantly reduced mechanical properties (femoral whole-bone stiffness and work to failure were markedly decreased), suggesting that compensatory increases of GH in states of IGF-1 deficiency (LID mice) act to protect against a severe inhibition of bone modeling during growth, which otherwise would result in bones that are too weak for normal and/or extreme loading conditions. Copyright © 2011 American Society for Bone and Mineral Research.

Feasibility of measuring selenium in humans using in vivo neutron activation analysis.

PubMed

Tahir, S N A; Chettle, D R; Byun, S H; Prestwich, W V

2015-11-01

Selenium (Se) is an element that, in trace quantities, plays an important role in the normal function of a number of biological processes in humans. Many studies have demonstrated that selenium deficiency in the body may contribute to an increased risk for certain neoplastic, cardiovascular, osseous, and nervous system diseases including retardation of bone formation. However, at higher concentrations Se is cytotoxic. For these reasons it is desirable to have a means of monitoring selenium concentration in humans.This paper presents the outcome of a feasibility study carried out for measuring selenium in humans using in vivo neutron activation analysis (IVNAA). In this technique a small dose of neutrons is delivered to the organ of interest, the neutrons are readily captured by the target nuclei, and the γ-rays given off are detected outside of the body. For the present study, human hand (bone) tissue equivalent phantoms were prepared with varying amounts of Se. These were irradiated by a low energy fast neutron beam produced by the (7)Li(p,n)(7)Be reaction employing the high beam current Tandetron accelerator. The counting data saved using a 4π NaI(TI) detection system were analyzed. The selenium was detected via the neutron capture reaction, (76)Se(n,γ)(77 m)Se, whereas calcium was detected through the (48)Ca(n,γ)(49)Ca reaction for the purpose of normalization of the Se signals to the calcium signals. From the calibration lines drawn between Se/Ca concentrations and Se/Ca counts ratio, the minimum detection limits (MDLs) were computed for two sets of phantoms irradiated under different irradiation parameters.In this study the optimized MDL value was determined to be 81 ng g(-1) (Se/phantom mass) for an equivalent dose of 188 mSv to the phantom. This MDL was found at least 10 times lower than the reported data on Se concentration measured in bone tissues. It was concluded that the NAA technique would be a feasible means of performing in vivo measurements of selenium in humans. Currently the data on in vivo measurement of selenium in humans are limited; the results of the present study would greatly contribute to the present data.

Gross, histologic, and computed tomographic characterization of nonpathological intrascleral cartilage and bone in the domestic goat (Capra aegagrus hircus).

PubMed

Tusler, Charlotte A; Good, Kathryn L; Maggs, David J; Zwingenberger, Allison L; Reilly, Christopher M

2017-05-01

To characterize grossly, histologically, and via computed tomography (CT) the appearance of intrascleral cartilage, bone, or both in domestic goats with otherwise normal eyes and to correlate this with age, sex, and breed. Sixty-eight domestic goats (89 eyes). Forty-nine formalin-fixed globes from 38 goats underwent high-resolution CT, and gross and light microscopic examination. An additional 40 eyes from 30 goats underwent light microscopy only. Age, breed, and sex of affected goats were retrieved from medical records. Considering all methods of evaluation collectively, cartilage was detected in 42% of eyes (44% of goats) and bone in 11% of eyes (12% of goats); bone was never seen without cartilage. Goats in which bone, cartilage, or both were detected ranged from 0.25 to 13 (median = 3.5) years of age, represented 11 of 12 breeds of the study population, and had a male:female ratio of 11:19. Bone was detected in the eyes of significantly more males (n = 8) than females (n = 2). No sex predilection was noted for cartilage alone. Histology revealed intrascleral chondrocyte-like cells, hyaline cartilage, and islands of lamellar bone. Some regions of bone had central, adipose-rich, marrow-like cavities. CT localized mineralized tissue as adjacent to or partially surrounding the optic nerve head. This is the first report of intrascleral bone or cartilage in a normal goat and of intrascleral bone in an otherwise normal mammal. The high prevalence of intrascleral cartilage and bone in this study suggests that this finding is normal and likely represents an adaptation in goats. © 2016 American College of Veterinary Ophthalmologists.

Growth, body composition, and bone density following pediatric liver transplantation.

PubMed

Sheikh, Amin; Cundy, Tim; Evans, Helen Maria

2018-04-24

Patients transplanted for cholestatic liver disease are often significantly fat-soluble vitamin deficient and malnourished pretransplant, with significant corticosteroid exposure post-transplant, with increasing evidence of obesity and metabolic syndrome post-LT. Our study aimed to assess growth, body composition, and BMD in patients post-pediatric LT. Body composition and bone densitometry scans were performed on 21 patients. Pre- and post-transplant anthropometric data were analyzed. Bone health was assessed using serum ALP, calcium, phosphate, and procollagen-1-N-peptide levels. Median ages at transplant and at this assessment were 2.7 and 10.6 years, respectively. Physiological markers of bone health, median z-scores for total body, and lumbar spine aBMD were normal. Bone area was normal for height and BMAD at L3 was normal for age, indicating, respectively, normal cortical and trabecular bone accrual. Median z-scores for weight, height, and BMI were 0.6, -0.9, 1.8 and 0.6, 0.1, 0.8 pre- and post-transplant, respectively. Total body fat percentages measured on 21 body composition scans revealed 2 underweight, 7 normal, 6 overweight, and 6 obese. Bone mass is preserved following pediatric LT with good catch-up height. About 52% of patients were either overweight/obese post-transplant, potentially placing them at an increased risk of metabolic syndrome and its sequelae in later life. BMI alone is a poor indicator of nutritional status post-transplant. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Regional responsiveness of the tibia to intermittent administration of parathyroid hormone as affected by skeletal unloading

NASA Technical Reports Server (NTRS)

Halloran, B. P.; Bikle, D. D.; Harris, J.; Tanner, S.; Curren, T.; Morey-Holton, E.

1997-01-01

To determine whether the acute inhibition of bone formation and deficit in bone mineral induced by skeletal unloading can be prevented, we studied the effects of intermittent parathyroid hormone (PTH) administration (8 micrograms/100 g/day) on growing rats submitted to 8 days of skeletal unloading. Loss of weight bearing decreased periosteal bone formation by 34 and 51% at the tibiofibular junction and tibial midshaft, respectively, and reduced the normal gain in tibial mass by 35%. Treatment with PTH of normally loaded and unloaded animals increased mRNA for osteocalcin (+58 and +148%, respectively), cancellous bone volume in the proximal tibia (+41 and +42%, respectively), and bone formation at the tibiofibular junction (+27 and +27%, respectively). Formation was also stimulated at the midshaft in unloaded (+47%, p < 0.05), but not loaded animals (-3%, NS). Although cancellous bone volume was preserved in PTH-treated, unloaded animals, PTH did not restore periosteal bone formation to normal nor prevent the deficit in overall tibial mass induced by unloading. We conclude that the effects of PTH on bone formation are region specific and load dependent. PTH can prevent the decrease in cancellous bone volume and reduce the decrement in cortical bone formation induced by loss of weight bearing.

Deletion of ameloblastin exon 6 is associated with amelogenesis imperfecta.

PubMed

Poulter, James A; Murillo, Gina; Brookes, Steven J; Smith, Claire E L; Parry, David A; Silva, Sandra; Kirkham, Jennifer; Inglehearn, Chris F; Mighell, Alan J

2014-10-15

Amelogenesis imperfecta (AI) describes a heterogeneous group of inherited dental enamel defects reflecting failure of normal amelogenesis. Ameloblastin (AMBN) is the second most abundant enamel matrix protein expressed during amelogenesis. The pivotal role of AMBN in amelogenesis has been confirmed experimentally using mouse models. However, no AMBN mutations have been associated with human AI. Using autozygosity mapping and exome sequencing, we identified genomic deletion of AMBN exon 6 in a second cousin consanguineous family with three of the six children having hypoplastic AI. The genomic deletion corresponds to an in-frame deletion of 79 amino acids, shortening the protein from 447 to 368 residues. Exfoliated primary teeth (unmatched to genotype) were available from family members. The most severely affected had thin, aprismatic enamel (similar to that reported in mice homozygous for Ambn lacking exons 5 and 6). Other teeth exhibited thicker but largely aprismatic enamel. One tooth had apparently normal enamel. It has been suggested that AMBN may function in bone development. No clinically obvious bone or other co-segregating health problems were identified in the family investigated. This study confirms for the first time that AMBN mutations cause non-syndromic human AI and that mouse models with disrupted Ambn function are valid. © The Author 2014. Published by Oxford University Press.

Bone disease in cystic fibrosis: new pathogenic insights opening novel therapies.

PubMed

Jacquot, J; Delion, M; Gangloff, S; Braux, J; Velard, F

2016-04-01

Mutations within the gene encoding for the chloride ion channel cystic fibrosis transmembrane conductance regulator (CFTR) results in cystic fibrosis (CF), the most common lethal autosomal recessive genetic disease that causes a number of long-term health problems, as the bone disease. Osteoporosis and increased vertebral fracture risk associated with CF disease are becoming more important as the life expectancy of patients continues to improve. The etiology of low bone density is multifactorial, most probably a combination of inadequate peak bone mass during puberty and increased bone losses in adults. Body mass index, male sex, advanced pulmonary disease, malnutrition and chronic therapies are established additional risk factors for CF-related bone disease (CFBD). Consistently, recent evidence has confirmed that CFTR plays a major role in the osteoprotegerin (OPG) and COX-2 metabolite prostaglandin E2 (PGE2) production, two key regulators in the bone formation and regeneration. Several others mechanisms were also recognized from animal and cell models contributing to malfunctions of osteoblast (cell that form bone) and indirectly of bone-resorpting osteoclasts. Understanding such mechanisms is crucial for the development of therapies in CFBD. Innovative therapeutic approaches using CFTR modulators such as C18 have recently shown in vitro capacity to enhance PGE2 production and normalized the RANKL-to-OPG ratio in human osteoblasts bearing the mutation F508del-CFTR and therefore potential clinical utility in CFBD. This review focuses on the recently identified pathogenic mechanisms leading to CFBD and potential future therapies for treating CFBD.

Runx2- and histone deacetylase 3-mediated repression is relieved in differentiating human osteoblast cells to allow high bone sialoprotein expression.

PubMed

Lamour, Virginie; Detry, Cédric; Sanchez, Christelle; Henrotin, Yves; Castronovo, Vincent; Bellahcène, Akeila

2007-12-14

Bone sialoprotein (BSP) is a bone matrix glycoprotein whose expression coincides with terminal osteoblastic differentiation and the onset of mineralization. In this study we show that BSP expression is considerably increased in confluent Saos-2 human osteosarcoma cells and in differentiating normal human osteoblasts, concomitantly with the decrease of Runx2, a key transcription factor controlling bone formation. Therefore, we investigated the role of Runx2 in the regulation of BSP expression in Saos-2 cells. Using a mobility shift assay, we demonstrated that Runx2 binds to the BSP promoter only in preconfluent cells. Histone deacetylase 3 (HDAC3) has been recently shown to act as a Runx2 co-repressor. Chromatin immunoprecipitation assays demonstrated that both Runx2 and HDAC3 are detectable at the BSP promoter in preconfluent Saos-2 cells but not when they are confluent and overexpress BSP. Consistently, nuclear Runx2 protein level is down-regulated, whereas Saos-2 cells became increasingly confluent. Finally, the suppression of HDAC3, Runx2, or both by RNA interference induced the expression of BSP at both mRNA and protein levels in Saos-2 cells. Our data demonstrate that Runx2 and HDAC3 repress BSP gene expression and that this repression is suspended upon osteoblastic cell differentiation. Both the nuclear disappearance of Runx2 and the non-recruitment of HDAC3 represent new means to relieve Runx2-mediated suppression of BSP expression, thus allowing the acquisition of a fully differentiated and mineralization-competent phenotype by osteoblast cells.

Does bone measurement on the radius indicate skeletal status. Concise communication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazess, R.B.; Peppler, W.W.; Chesney, R.W.

1984-03-01

Single-photon (I-125) absorptiometry was used to measure bone mineral content (BMC) of the distal third of the radius, and dual-photon absorptiometry (Gd-153) was used to measure total-body bone mineral (TBBM), as well as the BMC of major skeletal regions. Measurements were done in normal females, normal males, osteoporotic females, osteoporotic males, and renal patients. The BMC of the radius predicted TBBM well in normal subjects, but was less satisfactory in the patient groups. The spinal BMC was predicted with even lower accuracy from radius measurement. The error in predicting areal density (bone mass per unit projected skeletal area) of themore » lumbar and thoracic spine from the radius BMC divided by its width was smaller, but the regressions differed significantly among normals, osteoporotics, and renal patients. There was a preferential spinal osteopenia in the osteoporotic group and in about half of the renal patients. Bone measurements on the radius can indicate overall skeletal status in normal subjects and to a lesser degree in patients, but these radius measurements are inaccurate, even on the average, as an indicator of spinal state.« less

The effects of programmed administration of human parathyroid hormone fragment (1-34) on bone histomorphometry and serum chemistry in rats

NASA Technical Reports Server (NTRS)

Dobnig, H.; Turner, R. T.

1997-01-01

PTH treatment can result in dramatic increases in cancellous bone volume in normal and osteopenic rats. However, this potentially beneficial response is only observed after pulsatile treatment; continuous infusion of PTH leads to hypercalcemia and bone abnormalities. The purpose of these studies was to determine the optimal duration of the PTH pulses. A preliminary study revealed that human PTH-(1-34) (hPTH) is cleared from circulation within 6 h after sc administration of an anabolic dose of the hormone (80 microg/kg). To establish the effects of gradually extending the duration of exposure to hPTH without increasing the daily dose, we programmed implanted Alzet osmotic pumps to deliver the 80 microg/kg x day dose of the hormone during pulses of 1, 2, and 6 h/day, or 40 microg/kg x day continuously. Discontinuous infusion was accomplished by alternate spacing of external tubing with hPTH solution and sesame oil. After 6 days of treatment, we evaluated serum chemistry and bone histomorphometry. As negative and positive controls, groups of rats received pumps that delivered vehicle only and 80 microg/kg x day hPTH by daily sc injection, respectively. Dynamic and static bone histomorphometry revealed that the daily sc injection and 1 h/day infusion dramatically increased osteoblast number and bone formation in the proximal tibial metaphysis, whereas longer infusion resulted in systemic side-effects, including up to a 10% loss in body weight, hypercalcemia, and histological changes in the proximal tibia resembling abnormalities observed in patients with chronic primary hyperparathyroidism, including peritrabecular marrow fibrosis and focal bone resorption. Infusion for as little as 2 h/day resulted in minor weight loss and changes in bone histology that were intermediate between sc and continuous administration. The results demonstrate that the therapeutic interval for hPTH exposure is brief, but that programmed administration of implanted hormone is a feasible alternative to daily injection as a route for administration of the hormone.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagemaker, G.; Visser, T.P.; van Bekkum, D.W.

alpha-Thalassemic heterozygous (Hbath/+) mice were used to investigate the possible selective advantage of transplanted normal (+/+) hemopoietic cells. Without conditioning by total-body irradiation (TBI), infusion of large numbers of normal bone marrow cells failed to correct the thalassemic peripheral blood phenotype. Since the recipients' stem cells are normal with respect to number and differentiation capacity, it was thought that the transplanted stem cells were not able to lodge, or that they were not stimulated to proliferate. Therefore, a nonlethal dose of TBI was given to temporarily reduce endogenous stem cell numbers and hemopoiesis. TBI doses of 2 or 3 Gymore » followed by infusion of normal bone marrow cells proved to be effective in replacing the thalassemic red cells by normal red cells, whereas a dose of 1 Gy was ineffective. It is concluded that cure of thalassemia by bone marrow transplantation does not necessarily require eradication of thalassemic stem cells. Consequently, the objectives of conditioning regimens for bone marrow transplantation of thalassemic patients (and possibly other nonmalignant hemopoietic disorders) should be reconsidered.« less

[Diagnosis and treatment of Gaucher disease in Croatia].

PubMed

Mrsić, Mirando

2007-05-01

Gaucher disease is the most common lysosomal storage disorder. Incidence of disease is around 1:40-60,000 inhabitants and it is assuming that in Croatia we have 20-30 patients with Morbus Gaucher. Morbus Gaucher is recognized in three types. Type I or so called non-neuropatic from is most common in Europe while so called neuropatic forms (type II and III) are much rare (5-10%). Type II and III are characterized by central nervous system involvement and usually are diagnosed in childhood. Disease manifestations are observed in various human organs. The most common disease features are involved liver, spleen, bones, lungs and brain. Enzyme replacement therapy with imiglucerase (Cerezyme) is now day's therapeutic gold standard. Imiglucerase prevents progressive manifestation of disease and patients have normal life. Cost of the treatment is high due to the cost of the recombinant technology which was used to product imiglucerase. The cost of the enzyme replacement therapy is 150-200,000 EUR per year for imiglucerase in a typical adult patient. Because of high cost for the patient treatment Ministry of Health of Republic of Croatia, and Croatian Health Insurance Company in year 2002. established a special program for so called "Expensive drug treatment". This program covering treatment costs for patients with inherited metabolic disorders, adenosine deaminase deficiency, chronic myeloid leukemia, AIDS, multiple sclerosis, juvenile arthritis and ovarian cancer. Until now 11 adult patients and 2 children with Gaucher disease were diagnosed in Croatia and all are on enzyme replacement therapy with imiglucerase. According to our experience administration of imiglucerase decreased spleen and liver size and number of bone pain crisis as well as normalization of platelet and red blood cells. Administration of the imiglucerase do no revert bone changes e.g. avascular hip necrosis or vertebra collapses, but prevent further bone deterioration. According to this, treatment with imiglucerase should be started immediately after establishing diagnosis to prevent irreversible changes on human organs.

The relation of microdamage to fracture and material property degradation in human cortical bone tissue

NASA Astrophysics Data System (ADS)

Akkus, Ozan

This dissertation investigates the relation of microdamage to fracture and material property degradation of human cortical bone tissue. Fracture resistance and fatigue crack growth of microcracks were examined experimentally and material property degradation was examined through theoretical modeling. To investigate the contribution of microdamage to static fracture resistance, fracture toughness tests were conducted in the transverse and longitudinal directions to the osteonal orientation of normal bone tissue. Damage accumulation was monitored by acoustic emission during testing and was spatially observed by histological observation following testing. The results suggested that the propagation of the main crack involved weakening of the tissue by diffuse damage at the fracture plane and by formation of linear microcracks away from the fracture plane for the transverse specimens. For the longitudinal specimens, growth of the main crack occurred in the form of separations at lamellar interfaces. Acoustic emission results supported the histological observations. To investigate the contribution of ultrastructure to static fracture resistance, fracture toughness tests were conducted after altering the collagen phase of the bone tissue by gamma radiation. A significant decrease in the fracture toughness, Work-to-Fracture and the amount damage was observed due to irradiation in both crack growth directions. For cortical bone irradiated at 27.5kGy, fracture toughness is reduced due to the inhibition of damage formation at and near the crack tip. Microcrack fatigue crack growth and arrest were investigated through observations of surface cracks during cyclic loading. At the applied cyclic stresses, the microcracks propagated and arrested in less than 10,000 cycles. In addition, the microcracks were observed not to grow beyond a length of 150mum and a DeltaK of 0.5MNm-3/2, supporting a microstructural barrier concept. Finally, the contribution of linear microcracks to material property degradation was examined by developing a theoretical micromechanical damage model. The model was compared to experimentally induced damage in bone tissue. The percent contribution of linear microcracks to the total degradation was predicted to be less than 5%, indicating that diffuse damage or an unidentified form of damage is primarily responsible for material property degradation in human cortical bone tissue.

Osteopathia striata with cranial sclerosis: clinical, radiological, and bone histological findings in an adolescent girl.

PubMed

Ward, L M; Rauch, F; Travers, R; Roy, M; Montes, J; Chabot, G; Glorieux, F H

2004-08-15

Osteopathia striata with cranial sclerosis (OS-CS) is a rare skeletal dysplasia characterized by linear striations of the long bones, osteosclerosis of the cranium, and extra-skeletal anomalies. We provide a comprehensive description of the skeletal phenotype in a French-Canadian girl with a moderate to severe form of sporadic OS-CS. Multiple medical problems, including anal stenosis and the Pierre-Robin sequence, were evident in the first few years of life. At 14 years, she was fully mobile, with normal intellect and stature. She suffered chronic lower extremity pain in the absence of fractures, as well as severe headaches, unilateral facial paralysis, and bilateral mixed hearing loss. Biochemical indices of bone and mineral metabolism were within normal limits. Bone densitometry showed increased areal bone mineral density in the skull, trunk, and pelvis, but not in the upper and lower extremities. An iliac bone biopsy specimen revealed an increased amount of trabecular bone. Trabeculae were abnormally thick, but there was no evidence of disturbed bone remodeling. In a cranial bone specimen, multiple layers of periosteal bone were found that covered a compact cortical compartment containing tightly packed haversian canals. Bone lamellation was normal in both the iliac and skull samples. Osteoclast differentiation studies showed that peripheral blood osteoclast precursors from this patient formed functional osteoclasts in vitro. Thus, studies of bone metabolism did not explain why bone mass is increased in most skeletal areas of this patient. Cranial histology points to exuberant periosteal bone formation as a potential cause of the cranial sclerosis.

Differentiating human bone from animal bone: a review of histological methods.

PubMed

Hillier, Maria L; Bell, Lynne S

2007-03-01

This review brings together a complex and extensive literature to address the question of whether it is possible to distinguish human from nonhuman bone using the histological appearance of cortical bone. The mammalian species included are rat, hare, badger, racoon dog, cat, dog, pig, cow, goat, sheep, deer, horse, water buffalo, bear, nonhuman primates, and human and are therefore not exhaustive, but cover those mammals that may contribute to a North American or Eurasian forensic assemblage. The review has demonstrated that differentiation of human from certain nonhuman species is possible, including small mammals exhibiting Haversian bone tissue and large mammals exhibiting plexiform bone tissue. Pig, cow, goat, sheep, horse, and water buffalo exhibit both plexiform and Haversian bone tissue and where only Haversian bone tissue exists in bone fragments, differentiation of these species from humans is not possible. Other primate Haversian bone tissue is also not distinguishable from humans. Where differentiation using Haversian bone tissue is undertaken, both the general microstructural appearance and measurements of histological structures should be applied. Haversian system diameter and Haversian canal diameter are the most optimal and diagnostic measurements to use. Haversian system density may be usefully applied to provide an upper and lower limit for humans.

Biomechanical measurements of stiffness and strength for five types of whole human and artificial humeri.

PubMed

Aziz, Mina S R; Nicayenzi, Bruce; Crookshank, Meghan C; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2014-05-01

The human humerus is the third largest longbone and experiences 2-3% of all fractures. Yet, almost no data exist on its intact biomechanical properties, thus preventing researchers from obtaining a full understanding of humerus behavior during injury and after being repaired with fracture plates and nails. The aim of this experimental study was to compare the biomechanical stiffness and strength of "gold standard" fresh-frozen humeri to a variety of humerus models. A series of five types of intact whole humeri were obtained: human fresh-frozen (n = 19); human embalmed (n = 18); human dried (n = 15); artificial "normal" (n = 12); and artificial "osteoporotic" (n = 12). Humeri were tested under "real world" clinical loading modes for shear stiffness, torsional stiffness, cantilever bending stiffness, and cantilever bending strength. After removing geometric effects, fresh-frozen results were 585.8 ± 181.5 N/mm2 (normalized shear stiffness); 3.1 ± 1.1 N/(mm2 deg) (normalized torsional stiffness); 850.8 ± 347.9 N/mm2 (normalized cantilever stiffness); and 8.3 ± 2.7 N/mm2 (normalized cantilever strength). Compared to fresh-frozen values, statistical equivalence (p ≥ 0.05) was obtained for all four test modes (embalmed humeri), 1 of 4 test modes (dried humeri), 1 of 4 test modes (artificial "normal" humeri), and 1 of 4 test modes (artificial "osteoporotic" humeri). Age and bone mineral density versus experimental results had Pearson linear correlations ranging from R = -0.57 to 0.80. About 77% of human humeri failed via a transverse or oblique distal shaft fracture, whilst 88% of artificial humeri failed with a mixed transverse + oblique fracture. To date, this is the most comprehensive study on the biomechanics of intact human and artificial humeri and can assist researchers to choose an alternate humerus model that can substitute for fresh-frozen humeri.

Leukemia-associated antigens in man.

PubMed

Brown, G; Capellaro, D; Greaves, M

1975-12-01

Rabbit antisera raised against acute lymphoblastic leukemia (ALL) cells were used to distinguish ALL from other leukemias, to identify rare leukemia cells in the bone marrow of patients in remission, and to define human leukemia-associated antigens. Antibody binding was studied with the use of immunofluorescence reagents and the analytic capacity of the Fluorescence Activated Cell Sorter-1 (FACS-1). The results indicated that most non-T-cell ALL have three leukemia-associated antigens on their surface which are absent from normal lymphoid cells: 1) an antigen shared with myelocytes, myeloblastic leukemia cells, and fetal liver (hematopoietic) cells; 2) an antigen shared with a subset of intermediate normoblasts in normal bone marrow and fetal liver; and 3) an antigen found thus far only on non-T-cell ALL and in some acute undifferentiated leukemias, which we therefore regard as a strong candidate for a leukemia-specific antigen. These antigens are absent from a subgroup of ALL patients in which the lymphoblasta express T-cell surface markers. Preliminary studies on the bone marrow samples of patients in remission indicated that rare leukemia cells were present in some samples. The implications of these findings with respect to the heterogeneity and cell origin(s) of ALL, its diagnosis, and its potential monitoring during treatment were discussed.

Leptin is an effective treatment for hypothalamic amenorrhea

PubMed Central

Chou, Sharon H.; Chamberland, John P.; Liu, Xiaowen; Matarese, Giuseppe; Gao, Chuanyun; Stefanakis, Rianna; Brinkoetter, Mary T.; Gong, Huizhi; Arampatzi, Kalliopi; Mantzoros, Christos S.

2011-01-01

Hypothalamic amenorrhea (HA) is associated with dysfunction of the hypothalamic-pituitary-peripheral endocrine axes, leading to infertility and bone loss, and usually is caused by chronic energy deficiency secondary to strenuous exercise and/or decreased food intake. Energy deficiency also leads to hypoleptinemia, which has been proposed, on the basis of observational studies as well as an open-label study, to mediate the neuroendocrine abnormalities associated with this condition. To prove definitively a causal role of leptin in the pathogenesis of HA, we performed a randomized, double-blinded, placebo-controlled trial of human recombinant leptin (metreleptin) in replacement doses over 36 wk in women with HA. We assessed its effects on reproductive outcomes, neuroendocrine function, and bone metabolism. Leptin replacement resulted in recovery of menstruation and corrected the abnormalities in the gonadal, thyroid, growth hormone, and adrenal axes. We also demonstrated changes in markers of bone metabolism suggestive of bone formation, but no changes in bone mineral density were detected over the short duration of this study. If these data are confirmed, metreleptin administration in replacement doses to normalize circulating leptin levels may prove to be a safe and effective therapy for women with HA. PMID:21464293

Leptin is an effective treatment for hypothalamic amenorrhea.

PubMed

Chou, Sharon H; Chamberland, John P; Liu, Xiaowen; Matarese, Giuseppe; Gao, Chuanyun; Stefanakis, Rianna; Brinkoetter, Mary T; Gong, Huizhi; Arampatzi, Kalliopi; Mantzoros, Christos S

2011-04-19

Hypothalamic amenorrhea (HA) is associated with dysfunction of the hypothalamic-pituitary-peripheral endocrine axes, leading to infertility and bone loss, and usually is caused by chronic energy deficiency secondary to strenuous exercise and/or decreased food intake. Energy deficiency also leads to hypoleptinemia, which has been proposed, on the basis of observational studies as well as an open-label study, to mediate the neuroendocrine abnormalities associated with this condition. To prove definitively a causal role of leptin in the pathogenesis of HA, we performed a randomized, double-blinded, placebo-controlled trial of human recombinant leptin (metreleptin) in replacement doses over 36 wk in women with HA. We assessed its effects on reproductive outcomes, neuroendocrine function, and bone metabolism. Leptin replacement resulted in recovery of menstruation and corrected the abnormalities in the gonadal, thyroid, growth hormone, and adrenal axes. We also demonstrated changes in markers of bone metabolism suggestive of bone formation, but no changes in bone mineral density were detected over the short duration of this study. If these data are confirmed, metreleptin administration in replacement doses to normalize circulating leptin levels may prove to be a safe and effective therapy for women with HA.

Gonadal steroids and bone metabolism in men.

PubMed

Leder, Benjamin

2007-06-01

Over the past decade, our increasing awareness of the clinical importance of osteoporosis in men has stimulated intense interest in trying to better understand male skeletal physiology and pathophysiology. The present review focuses on a major focus of research in this area, namely the attempt to define the influence and therapeutic potential of gonadal steroids in male bone metabolism. Building on previous work defining the relative roles of androgens and estrogens in the developing male skeleton and in maintaining normal bone turnover, recent studies have begun to define these issues from epidemiologic, physiologic and therapeutic perspectives. With access to data from large prospectively defined populations of men, investigators are confirming and challenging existing hypotheses and forwarding new concepts. Clinical trials have expanded beyond standard androgen replacement studies to explore more complex hormonal interventions. Physiologic investigation has continued to probe the mechanisms underlying the differential and independent roles of androgens and estrogens in male bone metabolism. Recent work has added significantly to our understanding of the role of gonadal steroids in male skeletal physiology. Nonetheless, further research is necessary to build on these initial human studies and to capitalize on rapidly emerging advances in our understanding of the basic biology of bone metabolism.

The importance of vitamins D and K for the bone health and immune function in inflammatory bowel disease.

PubMed

Iijima, Hideki; Shinzaki, Shinichiro; Takehara, Tetsuo

2012-11-01

This review summarizes the recent literature about the roles of vitamins D and K in bone metabolism and immunity-mediated inflammatory processes in inflammatory bowel diseases (IBDs). The levels of vitamins D and K are lower than normal in patients with IBD, especially in Crohn's disease. Although vitamins D and K are important for the maintenance of bone mineral density in non-IBD patients, an association between vitamins D or K and bone metabolism is not apparent in IBD patients. Recent studies showed that vitamins D and K are suggested to have immune-suppressive effects, both in animal models of colitis and human trials. In particular, vitamin D suppresses dendritic and T-cell functions by inhibiting the production of proinflammatory cytokines. Insufficiency of vitamin D is associated with the activated phenotype of IBD. Vitamins D and K potentially contribute to the maintenance of bone health in IBD, but this effect may be diminished by other factors such as steroid use, reduced exposure to sunlight, and inflammatory cytokines. Vitamin D and possibly vitamin K are suggested to be involved in the suppression of immune-mediated inflammation and modulation of disease activity.

The role of intracellular calcium phosphate in osteoblast-mediated bone apatite formation

PubMed Central

Boonrungsiman, Suwimon; Gentleman, Eileen; Carzaniga, Raffaella; Evans, Nicholas D.; McComb, David W.; Porter, Alexandra E.; Stevens, Molly M.

2012-01-01

Mineralization is a ubiquitous process in the animal kingdom and is fundamental to human development and health. Dysfunctional or aberrant mineralization leads to a variety of medical problems, and so an understanding of these processes is essential to their mitigation. Osteoblasts create the nano-composite structure of bone by secreting a collagenous extracellular matrix (ECM) on which apatite crystals subsequently form. However, despite their requisite function in building bone and decades of observations describing intracellular calcium phosphate, the precise role osteoblasts play in mediating bone apatite formation remains largely unknown. To better understand the relationship between intracellular and extracellular mineralization, we combined a sample-preparation method that simultaneously preserved mineral, ions, and ECM with nano-analytical electron microscopy techniques to examine osteoblasts in an in vitro model of bone formation. We identified calcium phosphate both within osteoblast mitochondrial granules and intracellular vesicles that transported material to the ECM. Moreover, we observed calcium-containing vesicles conjoining mitochondria, which also contained calcium, suggesting a storage and transport mechanism. Our observations further highlight the important relationship between intracellular calcium phosphate in osteoblasts and their role in mineralizing the ECM. These observations may have important implications in deciphering both how normal bone forms and in understanding pathological mineralization. PMID:22879397

Bone regeneration of critical calvarial defect in goat model by PLGA/TCP/rhBMP-2 scaffolds prepared by low-temperature rapid-prototyping technology.

PubMed

Yu, D; Li, Q; Mu, X; Chang, T; Xiong, Z

2008-10-01

Active artificial bone composed of poly lactide-co-glycolide (PLGA)/ tricalcium phosphate (TCP) was prefabricated using low-temperature rapid-prototyping technology so that the process of osteogenesis could be observed in it. PLGA and TCP were the primary materials, they were molded at low temperature, then recombinant human bone morphogenetic protein-2 (rhBMP-2) was added to form an active artificial bone. Goats with standard cranial defects were randomly divided into experimental (implants with rhBMP-2 added) and control (implants without rhBMP-2) groups, and osteogenesis was observed and evaluated by imaging and biomechanical and histological examinations. The PLGA-TCP artificial bone scaffold (90% porosity) had large and small pores of approximately 360microm and 3-5microm diameter. Preliminary and complete repair of the cranial defect in the goats occurred 12 and 24 weeks after surgery, respectively. The three-point bending strength of the repaired defects attained that of the normal cranium. In conclusion, low-temperature rapid-prototyping technology can preserve the biological activity of this scaffold material. The scaffold has a good three-dimensional structure and it becomes an active artificial bone after loading with rhBMP-2 with a modest degradation rate and excellent osteogenesis in the goat.

Skeletal stem cell and bone implant interactions are enhanced by LASER titanium modification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sisti, Karin E., E-mail: karinellensisti@gmail.com; Biomaterials Group, Institute of Chemistry, São Paulo State University; Federal University of Mato Grosso do Sul

Purpose: To evaluate the osteo-regenerative potential of Titanium (Ti) modified by Light Amplification by Stimulated Emission of Radiation (LASER) beam (Yb-YAG) upon culture with human Skeletal Stem Cells (hSSCs{sup 1}). Methods: Human skeletal cell populations were isolated from the bone marrow of haematologically normal patients undergoing primary total hip replacement following appropriate consent. STRO-1{sup +} hSSC{sup 1} function was examined for 10 days across four groups using Ti discs: i) machined Ti surface group in basal media (Mb{sup 2}), ii) machined Ti surface group in osteogenic media (Mo{sup 3}), iii) LASER-modified Ti group in basal media (Lb{sup 4}) and, iv)more » LASER-modified Ti group in osteogenic media (Lo{sup 5}). Molecular analysis and qRT-PCR as well as functional analysis including biochemistry (DNA, Alkaline Phosphatase (ALP{sup 6}) specific activity), live/dead immunostaining (Cell Tracker Green (CTG{sup 7})/Ethidium Homodimer-1 (EH-1{sup 8})), and fluorescence staining (for vinculin and phalloidin) were undertaken. Inverted, confocal and Scanning Electron Microscopy (SEM) approaches were used to characterise cell adherence, proliferation, and phenotype. Results: Enhanced cell spreading and morphological rearrangement, including focal adhesions were observed following culture of hSSCs{sup 1} on LASER surfaces in both basal and osteogenic conditions. Biochemical analysis demonstrated enhanced ALP{sup 6} specific activity on the hSSCs{sup 1}-seeded on LASER-modified surface in basal culture media. Molecular analysis demonstrated enhanced ALP{sup 6} and osteopontin expression on titanium LASER treated surfaces in basal conditions. SEM, inverted microscopy and confocal laser scanning microscopy confirmed extensive proliferation and migration of human bone marrow stromal cells on all surfaces evaluated. Conclusions: LASER-modified Ti surfaces modify the behaviour of hSSCs.{sup 1} In particular, SSC{sup 1} adhesion, osteogenic gene expression, cell morphology and cytoskeleton structure were affected. The current studies show Ti LASER modification can enhance the osseointegration between Ti and skeletal cells, with important implications for orthopaedic application. - Highlights: • Bone stem cells on LASER Ti surface display enhanced cell growth and viability. • Bone stem cells on LASER Ti surface exhibit marked biocompatibility. • Human bone stem cells on LASER Ti surface exhibit altered morphology. • LASER Ti enhance osteogenic differentiation of human bone skeletal stem cells. • LASER Ti provides a unique approach to enhance osseointegration with the material.« less

Multiple congenital brachymetatarsia. A one-stage combined shortening and lengthening procedure without iliac bone graft.

PubMed

Kim, J S; Baek, G H; Chung, M S; Yoon, P W

2004-09-01

We performed nine metatarsal and three proximal phalangeal lengthenings in five patients with congenital brachymetatarsia of the first and one or two other metatarsal bones, by a one-stage combined shortening and lengthening procedure using intercalcary autogenous bone grafts from adjacent shortened metatarsal bones. Instead of the isolated lengthening of the first and the other metatarsal bones, we shortened the adjacent normal metatarsal and used the excised bone to lengthen the short toes, except for the great toe, to restore the normal parabola. One skin incision was used. All the operations were performed bilaterally and the patients were followed up for a mean period of 69.5 months (29 to 107). They all regained a nearly normal parabola and were satisfied with the cosmetic results. Our technique is straightforward and produces good cosmetic results. Satisfactory, bony union is achieved, morbidity is low, and no additional surgery is required for the removal of metal implants.

CRISPR/Cas9-mediated mutation of PHEX in rabbit recapitulates human X-linked hypophosphatemia (XLH).

PubMed

Sui, Tingting; Yuan, Lin; Liu, Huan; Chen, Mao; Deng, Jichao; Wang, Yong; Li, Zhanjun; Lai, Liangxue

2016-07-01

X-linked hypophosphatemia (XLH) is the most common cause of inheritable rickets, with an incidence of 1/20 000 in humans. Inactivation or mutation of the gene PHEX, a phosphate-regulating endopeptidase, leads to hypophosphatemia and defective bone mineralization in XLH patients. Presently, there is no adequate animal model for safety assessments of physiotherapies and drug screening for XLH rickets. In this study, an XLH model was generated via PHEX gene knockout (KO) through coinjection of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9)/sgRNA mRNA into rabbit zygotes. The typical phenotypes of growth retardation, hypophosphatemia, elevated serum FGF23 and bone mineralization were observed in the PHEX KO rabbits but not in normal controls. In summary, for the first time, we have successfully obtained PHEX KO rabbits and recapitulated human XLH using the CRISPR/Cas9 system. This novel XLH rabbit model could be utilized as a drug screening model for XLH prevention and preclinical therapy. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Anthropometric adjustments are helpful in the interpretation of BMD and BMC Z-scores of pediatric patients with Prader-Willi syndrome.

PubMed

Hangartner, T N; Short, D F; Eldar-Geva, T; Hirsch, H J; Tiomkin, M; Zimran, A; Gross-Tsur, V

2016-12-01

Anthropometric adjustments of bone measurements are necessary in Prader-Willi syndrome patients to correctly assess the bone status of these patients. This enables physicians to get a more accurate diagnosis of normal versus abnormal bone, allow for early and effective intervention, and achieve better therapeutic results. Bone mineral density (BMD) is decreased in patients with Prader-Willi syndrome (PWS). Because of largely abnormal body height and weight, traditional BMD Z-scores may not provide accurate information in this patient group. The goal of the study was to assess a cohort of individuals with PWS and characterize the development of low bone density based on two adjustment models applied to a dataset of BMD and bone mineral content (BMC) from dual-energy X-ray absorptiometry (DXA) measurements. Fifty-four individuals, aged 5-20 years with genetically confirmed PWS, underwent DXA scans of spine and hip. Thirty-one of them also underwent total body scans. Standard Z-scores were calculated for BMD and BMC of spine and total hip based on race, sex, and age for all patients, as well as of whole body and whole-body less head for those patients with total-body scans. Additional Z-scores were generated based on anthropometric adjustments using weight, height, and percentage body fat and a second model using only weight and height in addition to race, sex, and age. As many PWS patients have abnormal anthropometrics, addition of explanatory variables weight, height, and fat resulted in different bone classifications for many patients. Thus, 25-70 % of overweight patients, previously diagnosed as normal, were subsequently diagnosed as below normal, and 40-60 % of patients with below-normal body height changed from below normal to normal depending on bone parameter. This is the first study to include anthropometric adjustments into the interpretation of BMD and BMC in children and adolescents with PWS. This enables physicians to get a more accurate diagnosis of normal versus abnormal BMD and BMC and allows for early and effective intervention.

A Spectrum of Monoclonal Antibodies Reactive with Human Mammary Tumor Cells

NASA Astrophysics Data System (ADS)

Colcher, D.; Horan Hand, P.; Nuti, M.; Schlom, J.

1981-05-01

Splenic lymphocytes of mice, immunized with membrane-enriched fractions of metastatic human mammary carcinoma tissues, were fused with the NS-1 non-immunoglobulin-secreting murine myeloma cell line. This resulted in the generation of hybridoma cultures secreting immunoglobulins reactive in solid-phase radioimmunoassays with extracts of metastatic mammary carcinoma cells from involved livers, but not with extracts of apparently normal human liver. As a result of further screening of immunoglobulin reactivities and double cloning of cultures, 11 monoclonal antibodies were chosen that demonstrated reactivities with human mammary tumor cells and not with apparently normal human tissues. These monoclonal antibodies could be placed into at least five major groups on the basis of their differential binding to the surface of various live human mammary tumor cells in culture, to extracts of mammary tumor tissues, or to tissue sections of mammary tumor cells studied by the immunoperoxidase technique. Whereas a spectrum of reactivities to mammary tumors was observed with the 11 monoclonal antibodies, no reactivity was observed to apparently normal cells of the following human tissues: breast, lymph node, lung, skin, testis, kidney, thymus, bone marrow, spleen, uterus, thyroid, intestine, liver, bladder, tonsils, stomach, prostate, and salivary gland. Several of the antibodies also demonstrated a ``pancarcinoma'' reactivity, showing binding to selected non-breast carcinomas. None of the monoclonal antibodies showed binding to purified ferritin or carcinoembryonic antigen. Monoclonal antibodies of all five major groups, however, demonstrated binding to human metastatic mammary carcinoma cells both in axillary lymph nodes and at distal sites.

Is sonic Hedgehog involved in human fracture healing? --a prospective study on local and systemic concentrations of SHH.

PubMed

Eipeldauer, Stefan; Thomas, Anita; Hoechtl-Lee, Leonard; Kecht, Mathias; Binder, Harald; Koettstorfer, Julia; Gregori, Markus; Sarahrudi, Kambiz

2014-01-01

Sonic Hedgehog (SHH) is a new signalling pathway in bone repair. Evidence exist that SHH pathway plays a significant role in vasculogenesis and limb development during embryogenesis. Some in vitro and animal studies has already proven its potential for bone regeneration. However, no data on the role of SHH in the human fracture healing have been published so far. Seventy-five patients with long bone fractures were included into the study and divided in 2 groups. First group contained 69 patients with normal fracture healing. Four patients with impaired fracture healing formed the second group. 34 volunteers donated blood samples as control. Serum samples were collected over a period of 1 year following a standardized time schedule. In addition, SHH levels were measured in fracture haematoma and serum of 16 patients with bone fractures. Fracture haematoma and patients serum both contained lower SHH concentrations compared to control serum. The comparison between the patients' serum SHH level and the control serum revealed lower levels for the patients at all measurement time points. Significantly lower concentrations were observed at weeks 1 and 2 after fracture. SHH levels were slightly decreased in patients with impaired fracture healing without statistical significance. This is the first study to report local and systemic concentration of SHH in human fracture healing and SHH serum levels in healthy adults. A significant reduction of the SHH levels during the inflammatory phase of fracture healing was found. SHH concentrations in fracture haematoma and serum were lower than the concentration in control serum for the rest of the healing period. Our findings indicate that there is no relevant involvement of SHH in human fracture healing. Fracture repair process seem to reduce the SHH level in human. Further studies are definitely needed to clarify the underlying mechanisms.

Elimination of leukemic cells from human transplants by laser nano-thermolysis

NASA Astrophysics Data System (ADS)

Lapotko, Dmitri; Lukianova, Ekaterina; Potapnev, Michail; Aleinikova, Olga; Oraevsky, Alexander

2006-02-01

We describe novel ex vivo method for elimination of tumor cells from bone marrow and blood, Laser Activated Nano-Thermolysis for Cell Elimination Technology (LANTCET) and propose this method for purging of transplants during treatment of leukemia. Human leukemic cells derived from real patients with different diagnoses (acute lymphoblastic leukemias) were selectively damaged by LANTCET in the experiments by laser-induced micro-bubbles that emerge inside individual specifically-targeted cells around the clusters of light-absorbing gold nanoparticles. Pretreatment of the transplants with diagnosis-specific primary monoclonal antibodies and gold nano-particles allowed the formation of nanoparticle clusters inside leukemic cells only. Electron microscopy found the nanoparticulate clusters inside the cells. Total (99.9%) elimination of leukemic cells targeted with specific antibodies and nanoparticles was achieved with single 10-ns laser pulses with optical fluence of 0.2 - 1.0 J/cm2 at the wavelength of 532 nm without significant damage to normal bone marrow cells in the same transplant. All cells were studied for the damage/viability with several control methods after their irradiation by laser pulses. Presented results have proved potential applicability of developed LANTCET technology for efficient and safe purging (cleaning of residual tumor cells) of human bone marrow and blood transplants. Design of extra-corporeal system was proposed that can process the transplant for one patient for less than an hour with parallel detection and counting residual leukemic cells.

Bone marrow invasion in multiple myeloma and metastatic disease.

PubMed

Vilanova, J C; Luna, A

2016-04-01

Magnetic resonance imaging (MRI) of the spine is the imaging study of choice for the management of bone marrow disease. MRI sequences enable us to integrate structural and functional information for detecting, staging, and monitoring the response the treatment of multiple myeloma and bone metastases in the spine. Whole-body MRI has been incorporated into different guidelines as the technique of choice for managing multiple myeloma and metastatic bone disease. Normal physiological changes in the yellow and red bone marrow represent a challenge in analyses to differentiate clinically significant findings from those that are not clinically significant. This article describes the findings for normal bone marrow, variants, and invasive processes in multiple myeloma and bone metastases. Copyright © 2015 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Microgravity

NASA Image and Video Library

1996-06-01

The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators

Microgravity

NASA Image and Video Library

1988-07-14

The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators.

Bioreactor

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators

Rotating Bioreactor

NASA Technical Reports Server (NTRS)

1988-01-01

The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators.

Decision tree analysis as a supplementary tool to enhance histomorphological differentiation when distinguishing human from non-human cranial bone in both burnt and unburnt states: A feasibility study.

PubMed

Simmons, T; Goodburn, B; Singhrao, S K

2016-01-01

This feasibility study was undertaken to describe and record the histological characteristics of burnt and unburnt cranial bone fragments from human and non-human bones. Reference series of fully mineralized, transverse sections of cranial bone, from all variables and specimen states, were prepared by manual cutting and semi-automated grinding and polishing methods. A photomicrograph catalogue reflecting differences in burnt and unburnt bone from human and non-humans was recorded and qualitative analysis was performed using an established classification system based on primary bone characteristics. The histomorphology associated with human and non-human samples was, for the main part, preserved following burning at high temperature. Clearly, fibro-lamellar complex tissue subtypes, such as plexiform or laminar primary bone, were only present in non-human bones. A decision tree analysis based on histological features provided a definitive identification key for distinguishing human from non-human bone, with an accuracy of 100%. The decision tree for samples where burning was unknown was 96% accurate, and multi-step classification to taxon was possible with 100% accuracy. The results of this feasibility study strongly suggest that histology remains a viable alternative technique if fragments of cranial bone require forensic examination in both burnt and unburnt states. The decision tree analysis may provide an additional but vital tool to enhance data interpretation. Further studies are needed to assess variation in histomorphology taking into account other cranial bones, ontogeny, species and burning conditions. © The Author(s) 2015.

Histological determination of the human origin from dry bone: a cautionary note for subadults.

PubMed

Caccia, Giulia; Magli, Francesca; Tagi, Veronica Maria; Porta, Davide Guido Ampelio; Cummaudo, Marco; Márquez-Grant, Nicholas; Cattaneo, Cristina

2016-01-01

Anthropologists are frequently required to confirm or exclude the human origin of skeletal remains; DNA and protein radioimmunoassays are useful in confirming the human origin of bone fragments but are not always successful. Histology may be the solution, but the young subadult structure could create misinterpretation. Histological tests were conducted on femur and skull of 31 human subjects. Each sample was observed focusing on presence or absence of fibrous bone, lamellar bone, radial lamellar bone, plexiform bone, reticular pattern, osteon banding, Haversian bone, primary osteons, secondary osteon and osteon fragments. Samples were divided into five age classes; 1 (<1 year), 2 (1-5 years), 3 (6-10 years), 4 (11-15 years) and 5 (16-20 years). Regarding femurs, class 1 presented the following: 87.5% fibrous bone, 37.5% plexiform bone, 12.5% reticular pattern and 12.5% lamellar bone radially oriented. Class 2 showed 37.5% of fibrous bone, 12.5% of reticular pattern and 37.5% of osteon banding. In the higher age classes, the classical human structures, lamellar bone and osteons were frequently visible, except for one case of reticular pattern, generally considered a distinctive non-human structure. The situation appeared different for the skull, where there was a lack of similar information, both in human and non-human. An analysis of the percentage of lamellar bone and osteons was conducted on femur and skull fragments. A trend of increase of primary osteon number and a decrease of the lamellar bone area has been detected in the femur. The present study has therefore shed some light on further pitfalls in species determination of subadult bone.

Bone age maturity assessment using hand-held device

NASA Astrophysics Data System (ADS)

Ratib, Osman M.; Gilsanz, Vicente; Liu, Xiaodong; Boechat, M. I.

2004-04-01

Purpose: Assessment of bone maturity is traditionally performed through visual comparison of hand and wrist radiograph with existing reference images in textbooks. Our goal was to develop a digital index based on idealized hand Xray images that can be incorporated in a hand held computer and used for visual assessment of bone age for patients. Material and methods: Due to the large variability in bone maturation in normals, we generated a set of "ideal" images obtained by computer combinations of images from our normal reference data sets. Software for hand-held PDA devices was developed for easy navigation through the set of images and visual selection of matching images. A formula based on our statistical analysis provides the standard deviation from normal based on the chronological age of the patient. The accuracy of the program was compared to traditional interpretation by two radiologists in a double blind reading of 200 normal Caucasian children (100 boys, 100 girls). Results: Strong correlations were present between chronological age and bone age (r > 0.9) with no statistical difference between the digital and traditional assessment methods. Determinations of carpal bone maturity in adolescents was slightly more accurate using the digital system. The users did praise the convenience and effectiveness of the digital Palm Index in clinical practice. Conclusion: An idealized digital Palm Bone Age Index provides a convenient and effective alternative to conventional atlases for the assessment of skeletal maturity.

Rabbit collagenase. Immunological identity of the enzymes released from cells and tissues in normal and pathological conditions.

PubMed Central

Werb, Z; Reynolds, J J

1975-01-01

1. The immunological cross-reactivity between rabbit collagenases from a variety of normal and pathological sources was examined. The specific antibody raised against collagenase secreted from normal rabbit synovial fibroblasts gave reactions of complete identity with collagenases secreted from fibroblasts derived from rabbit skin, and from synovium from experimentally arthritic rabbits. 2. The rabbit fibroblast collagenase was immunologically identical with collagenases obtained from the organ culture medium of normal rabbit skin, synovium, ear fibrocartilage and subchondral bone. 3. Collagenases from the culture media of normal rabbit synovium and from hyperplastic synovium of rabbits made experimentally arthritic were identical. 4. The collagenase secreted from rabbit fibroblasts gave a reaction completely identical with that of a collagenase extracted directly from a rabbit carcinoma. 5. IgG (immunoglobulin G) from a specific antiserum to rabbit fibroblast collagenase was a potent inhibitor of the collagenases obtained from the culture media of the various rabbit cells and tissues. 6. Collagenases from human synovium and from mouse macrophages and bone were neither precipitated nor inhibited by antibodies to rabbit collagenase. 7. No immunoreactive material was found in lysates of rabbit polymorphonuclear leucocyte granules with the specific antisera to rabbit fibroblast collagenase. No evidence for inactive forms of rabbit collagenase in lysates of the rabbit synovial fibroblasts could be found, either by double immunodiffusion against the specific collagenase, or by displacement of active enzyme from inhibition by the IgG. Images PLATE 1 PMID:56176

Bone marrow fat: linking adipocyte-induced inflammation with skeletal metastases

PubMed Central

Hardaway, Aimalie L.; Herroon, Mackenzie K.; Rajagurubandara, Erandi

2014-01-01

Adipocytes are important but underappreciated components of bone marrow microenvironment, and their numbers greatly increase with age, obesity, and associated metabolic pathologies. Age and obesity are also significant risk factors for development of metastatic prostate cancer. Adipocytes are metabolically active cells that secrete adipokines, growth factors, and inflammatory mediators; influence behavior and function of neighboring cells; and have a potential to disturb local milleu and dysregulate normal bone homeostasis. Increased marrow adiposity has been linked to bone marrow inflammation and osteoporosis of the bone, but its effects on growth and progression of prostate tumors that have metastasized to the skeleton are currently not known. This review focuses on fat-bone relationship in a context of normal bone homeostasis and metastatic tumor growth in bone. We discuss effects of marrow fat cells on bone metabolism, hematopoiesis, and inflammation. Special attention is given to CCL2- and COX-2-driven pathways and their potential as therapeutic targets for bone metastatic disease. PMID:24398857

[Osteoporosis treatment in patients with hyperthyroidism].

PubMed

Saito, Jun; Nishikawa, Tetsuo

2009-05-01

Childhood thyroid hormone (T3) is essential for the normal development of endochondral and intramembranous bone and plays an important role in the linear growth and maintenance of bone mass. In adult, T3 stimulates osteoclastic bone resorption mediated primarily by TR alpha and local conversion by deiodinase D2 may play a role in local activation. TSH seems to be an inhibitor of bone resorption and formation. In thyrotoxicosis patients with Graves' disease, there is increased bone remodelling, characterized by an imbalance between bone resorption and formation, which results in a decrease of bone mineral density (BMD) and an increased risk for osteoporotic fracture. Antithyroid treatment is able to reduce dramatically the bone resorption and to normalize BMD reduction. But previous hyperthyroidism is independently associated with an increased risk for fracture. Although further studies relating to the mechanism for possible impaired bone strength in these patients will be needed, bisphosphonates may be beneficial treatment for prevention of bone fractures in patients with severe risk for fractures, such as post-menopausal women.

Analysis of bone protein and mineral composition in bone disease using synchrotron infrared microspectroscopy

NASA Astrophysics Data System (ADS)

Miller, Lisa M.; Hamerman, David; Chance, Mark R.; Carlson, Cathy S.

1999-10-01

Infrared (IR) microspectroscopy is an analytical technique that is highly sensitive to the chemical components in bone. The brightness of a synchrotron source permits the examination of individual regions of bone in situ at a spatial resolution superior to that of a conventional infrared source. At Beamlines U10B and U2B at the National Synchrotron Light Source, we are examining the role of bone chemical composition in bone disease. In osteoarthritis (OA), it has been demonstrated that the bone underlying the joint cartilage (subchondral bone) becomes thickened prior to cartilage breakdown. Using synchrotron infrared microspectroscopy, we have examined the chemical composition of the subchondral bone in histologically normal and OA monkeys. Results demonstrate that the subchondral bone of OA monkeys is significantly more mineralized than the normal bone, primarily due to an increase in carbonate concentration in the OA bone. High resolution analysis indicates that differences in carbonate content are uniform throughout the subchondral bone region, suggesting that high subchondral bone carbonate may be a marker for OA. Conversely, increases in phosphate content are more pronounced in the region near the marrow space, suggesting that, as the subchondral bone thickens, the bone also becomes more mineralized. Osteoporosis is a disease characterized by a reduction in bone mass and a skeleton that is more susceptible to fracture. To date, it is unclear whether bone remodeled after the onset of osteoporosis differs in chemical composition from older bone. Using fluorescence-assisted infrared microspectroscopy, we are comparing the composition of monkey bone remodeled at various time points after the onset of osteoporosis (induced by ovariectomy). We find that the chemical composition of bone remodeled one year after ovariectomy and one year prior to necropsy is similar to normal bone. On the other hand, bone remodeled two years after ovariectomy is less mature, indicated by lower mineral/protein ratios and higher acid phosphate content. This immature bone may also be a symptom of slower bone formation rates related to estrogen deficiency.

Biomechanical comparison between the rectangular-tunnel and the round-tunnel anterior cruciate ligament reconstruction procedures with a bone-patellar tendon-bone graft.

PubMed

Suzuki, Tomoyuki; Shino, Konsei; Otsubo, Hidenori; Suzuki, Daisuke; Mae, Tatsuo; Fujimiya, Mineko; Yamashita, Toshihiko; Fujie, Hiromichi

2014-10-01

The purpose of this study was to evaluate the effectiveness of 2 anterior cruciate ligament (ACL) reconstruction techniques using a bone-patellar tendon-bone (BPTB) graft with femoral tunnel, either a rectangular tunnel (RET) or a round tunnel (ROT). For experiment 1, nine fresh-frozen human cadaveric knees were tested with a robotic/universal force-moment sensor system to determine the initial optimal tension: the amount of graft tension at 15° of flexion most closely resembling the anterior laxity of a normal knee. The value was estimated by repeatedly measuring anterior laxity when 100 N of anteroposterior drawer load was applied to the knees at 30° of flexion after RET ACL or ROT ACL reconstruction. For experiment 2, six fresh-frozen human cadaveric knees were selected. On the basis of the initial tension determined in experiment 1, RET ACL reconstruction was conducted with the graft tensioned to 10 N, followed by ROT ACL reconstruction on the same knee at 40 N of initial tension, and the biomechanical efficacy of the 2 methods was compared. For experiment 1, the mean laxity match tension at 15° of flexion was 8.6 ± 4.8 N and 34.8 ± 9.2 N for RET- and ROT-reconstructed knees, respectively. For experiment 2, both RET and ROT ACL reconstructions were successful in controlling anterior tibial translation under anterior tibial loads, with the graft initially tensioned to 10 N in the former and to 40 N in the latter. However, the greater tensioning in ROT reconstruction led to proximal, posterior, and lateral displacement of the tibia along with its external and valgus rotation. The RET ACL-reconstructed knee more closely resembled the normal knee in biomechanical behavior. Although ROT reconstruction successfully controlled anterior translation with greater initial tensioning to the graft, the normal positional relation between the tibia and femur was impaired. Rectangular femoral ACL fixation constructs and grafts may prove more efficacious at restoring in vivo ACL kinematics than round femoral tunnels. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Epigenetic and in vivo comparison of diverse MSC sources reveals an endochondral signature for human hematopoietic niche formation.

PubMed

Reinisch, Andreas; Etchart, Nathalie; Thomas, Daniel; Hofmann, Nicole A; Fruehwirth, Margareta; Sinha, Subarna; Chan, Charles K; Senarath-Yapa, Kshemendra; Seo, Eun-Young; Wearda, Taylor; Hartwig, Udo F; Beham-Schmid, Christine; Trajanoski, Slave; Lin, Qiong; Wagner, Wolfgang; Dullin, Christian; Alves, Frauke; Andreeff, Michael; Weissman, Irving L; Longaker, Michael T; Schallmoser, Katharina; Majeti, Ravindra; Strunk, Dirk

2015-01-08

In the last decade there has been a rapid expansion in clinical trials using mesenchymal stromal cells (MSCs) from a variety of tissues. However, despite similarities in morphology, immunophenotype, and differentiation behavior in vitro, MSCs sourced from distinct tissues do not necessarily have equivalent biological properties. We performed a genome-wide methylation, transcription, and in vivo evaluation of MSCs from human bone marrow (BM), white adipose tissue, umbilical cord, and skin cultured in humanized media. Surprisingly, only BM-derived MSCs spontaneously formed a BM cavity through a vascularized cartilage intermediate in vivo that was progressively replaced by hematopoietic tissue and bone. Only BM-derived MSCs exhibited a chondrogenic transcriptional program with hypomethylation and increased expression of RUNX3, RUNX2, BGLAP, MMP13, and ITGA10 consistent with a latent and primed skeletal developmental potential. The humanized MSC-derived microenvironment permitted homing and maintenance of long-term murine SLAM(+) hematopoietic stem cells (HSCs), as well as human CD34(+)/CD38(-)/CD90(+)/CD45RA(+) HSCs after cord blood transplantation. These studies underscore the profound differences in developmental potential between MSC sources independent of donor age, with implications for their clinical use. We also demonstrate a tractable human niche model for studying homing and engraftment of human hematopoietic cells in normal and neoplastic states. © 2015 by The American Society of Hematology.

Comparative cortical bone thickness between the long bones of humans and five common non-human mammal taxa.

PubMed

Croker, Sarah L; Reed, Warren; Donlon, Denise

2016-03-01

The task of identifying fragments of long bone shafts as human or non-human is difficult but necessary, for both forensic and archaeological cases, and a fast simple method is particularly useful. Previous literature suggests there may be differences in the thickness of the cortical bone between these two groups, but this has not been tested thoroughly. The aim of this study was not only to test this suggestion, but also to provide data that could be of practical assistance for future comparisons. The major limb bones (humerus, radius, femur and tibia) of 50 Caucasoid adult skeletons of known age and sex were radiographed, along with corresponding skeletal elements from sheep, pigs, cattle, large dogs and kangaroos. Measurements were taken from the radiographs at five points along the bone shaft, of shaft diameter, cortical bone thickness, and a cortical thickness index (sum of cortices divided by shaft diameter) in both anteroposterior and mediolateral orientations. Each variable for actual cortical bone thickness as well as cortical thickness indices were compared between the human group (split by sex) and each of the non-human groups in turn, using Student's t-tests. Results showed that while significant differences did exist between the human groups and many of the non-human groups, these were not all in the same direction. That is, some variables in the human groups were significantly greater than, and others were significantly less than, the corresponding variable in the non-human groups, depending on the particular non-human group, sex of the human group, or variable under comparison. This was the case for measurements of both actual cortical bone thickness and cortical thickness index. Therefore, for bone shaft fragments for which the skeletal element is unknown, the overlap in cortical bone thickness between different areas of different bones is too great to allow identification using this method alone. However, by providing extensive cortical bone thickness data for a range of bones, this study may be able to assist in the identification of some bone fragments by providing another piece of evidence that, used in conjunction with other clues, can provide a likely determination of the origin of a bone fragment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Trabecular bone microstructure is impaired in the proximal femur of human immunodeficiency virus-infected men with normal bone mineral density.

PubMed

Kazakia, Galateia J; Carballido-Gamio, Julio; Lai, Andrew; Nardo, Lorenzo; Facchetti, Luca; Pasco, Courtney; Zhang, Chiyuan A; Han, Misung; Parrott, Amanda Hutton; Tien, Phyllis; Krug, Roland

2018-02-01

There is evidence that human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are independent risk factors for osteoporosis and fracture which is not solely explained by changes in bone mineral density. Thus, we hypothesized that the assessment of trabecular microstructure might play an important role for bone quality in this population and might explain the increased fracture risk. In this study, we have assessed bone microstructure in the proximal femur using high-resolution magnetic resonance imaging (MRI) as well as in the extremities using high resolution peripheral quantitative computed tomography (HR-pQCT) in HIV-infected men and healthy controls and compared these findings to those based on areal bone mineral density (aBMD) derived from dual X-ray absorptiometry (DXA) which is the standard clinical parameter for the diagnosis of osteoporosis. Eight HIV-infected men and 11 healthy age-matched controls were recruited and informed consent was obtained before each scan. High-resolution MRI of the proximal femur was performed using fully balanced steady state free precession (bSSFP) on a 3T system. Three volumes of interest at corresponding anatomic locations across all subjects were defined based on registrations of a common template. Four MR-based trabecular microstructural parameters were analyzed at each region: fuzzy bone volume fraction (f-BVF), trabecular number (Tb.N), thickness (Tb.Th), and spacing (Tb.Sp). In addition, the distal radius and distal tibia were imaged with HR-pQCT. Four HR-pQCT-based microstructural parameters were analyzed: trabecular bone volume fraction (BV/TV), Tb.N, Tb.Th, and Tb.Sp. Total hip and spine aBMD were determined from DXA. Microstructural bone parameters derived from MRI at the proximal femur and from HR-pQCT at the distal tibia showed significantly lower bone quality in HIV-infected patients compared to healthy controls. In contrast, DXA aBMD data showed no significant differences between HIV-infected patients and healthy controls. Our results suggest that high-resolution imaging is a powerful tool to assess trabecular bone microstructure and can be used to assess bone health in HIV-infected men who show no differences to healthy males by DXA aBMD. Advances in MRI technology have made microstructural imaging at the proximal femur possible. Further studies in larger patient cohorts are clearly warranted.

Reduction of transforming growth factor-β1 expression in leukemia and its possible role in leukemia development.

PubMed

Wu, Yong; Chen, Ping; Huang, Hui-Fang; Huang, Mei-Juan; Chen, Yuan-Zhong

2012-01-01

The expression of transforming growth factor-β1 (TGF-β1) in leukemic cells and sera from patients with leukemia and its possible role in leukemia development were studied. TGF-β1 levels in culture supernatants from leukemic cells were significantly lower than those from normal bone marrow mononuclear cells. Serum TGF-β1 levels in leukemic patients were significantly lower compared with healthy controls, but returned to normal in patients achieving complete remission, and decreased when patients relapsed. TGF-β1 mRNA expression levels were significantly higher in normal bone marrow mononuclear cells but lower in leukemic cells compared with normal CD34 + cells. After transfection of the TGF-β1 gene to HL-60 cells, cell apoptosis was detected. Moreover, by flow cytometry analysis, cells arrested in G1 phase were 62% for TGF-β1 transfected cells and 44% for controls. Transfection of exogenous TGF-β1 gene inhibited HL60 cells xenograft growth in nude mice, and prolonged survival of tumor-bearing mice compared with the controls. Decreased endogenous TGF-β1 expression in leukemia cells may be involved in leukemia development, Transfection of exogenous TGF-B1 gene to HL60 can inhibit the proliferation of the cells and induce cell apoptosis by down regulating bcl-2, hTERT (human telomerase reverse transcriptase) and c-myc expression.

An atlas of radiological interpretation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calder, J.F.; Chessell, G.

1988-01-01

This book is concerned with pathologic entities and their impact on the skeleton. The book is divided into nine chapters. After a discussion of normal anatomic features, the authors discuss trauma, avascular necrosis and osteochondritis, bone infections, diseases of the joints, bone tumors, reticuloses and hemopoietic disorders, endocrine and metabolic bone diseases, and congenital abnormalities. A line drawing accompanies every radiograph to contrast the pathologic findings with the normal anatomic features.

Missense Mutations in LRP5 Associated with High Bone Mass Protect the Mouse Skeleton from Disuse- and Ovariectomy-Induced Osteopenia.

PubMed

Niziolek, Paul J; Bullock, Whitney; Warman, Matthew L; Robling, Alexander G

2015-01-01

The low density lipoprotein receptor-related protein-5 (LRP5), a co-receptor in the Wnt signaling pathway, modulates bone mass in humans and in mice. Lrp5 knock-out mice have severely impaired responsiveness to mechanical stimulation whereas Lrp5 gain-of-function knock-in and transgenic mice have enhanced responsiveness to mechanical stimulation. Those observations highlight the importance of Lrp5 protein in bone cell mechanotransduction. It is unclear if and how high bone mass-causing (HBM) point mutations in Lrp5 alter the bone-wasting effects of mechanical disuse. To address this issue we explored the skeletal effects of mechanical disuse using two models, tail suspension and Botulinum toxin-induced muscle paralysis, in two different Lrp5 HBM knock-in mouse models. A separate experiment employing estrogen withdrawal-induced bone loss by ovariectomy was also conducted as a control. Both disuse stimuli induced significant bone loss in WT mice, but Lrp5 A214V and G171V were partially or fully protected from the bone loss that normally results from disuse. Trabecular bone parameters among HBM mice were significantly affected by disuse in both models, but these data are consistent with DEXA data showing a failure to continue growing in HBM mice, rather than a loss of pre-existing bone. Ovariectomy in Lrp5 HBM mice resulted in similar protection from catabolism as was observed for the disuse experiments. In conclusion, the Lrp5 HBM alleles offer significant protection from the resorptive effects of disuse and from estrogen withdrawal, and consequently, present a potential mechanism to mimic with pharmaceutical intervention to protect against various bone-wasting stimuli.

Mouse fibroblasts homozygous for c-Src oncogene disruption shows dramatic suppression of expression of the gene encoding osteopontin, and adhesive phosphoprotein implicated in bone differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chackalaparampil, I.; Mukherjee, B.B.; Peri, A.

1994-09-01

Osteopetrosis, affecting mice and humans alike, arises from reduced or impaired bone resorption, causing abnormally dense bone formation. Normal bone differentiation requires continuous resorption and remodeling by osteoclasts which are derived from monocyte/macrophage lineage in the bone marrow. It has been reported that targeted homozygous disruption of c-src proto-oncogene in mice results in the development of osteopetrosis due to impaired bone-resorbing function of osteoclast cells. However, the molecular mechanism(s) which leads to osteoclast dysfunction in c-src deficient (src{sup -/-}) mice remains unclear. Here, we report that in embryonic fibroblasts derived from homozygous Src{sup -/-} mice, the expression of the genemore » coding for osteopontin (OP), a phosphorylated glycoprotein involved in bone differentiation, is drastically repressed. OP gene expression is not, however, affected in the heterozygous (Src{sup +/-}) mutant cells of identical origin, or in the c-src expression and OP production. Moreover, OP expression in c-src-deficient cells could be rescued upon treatment with 12-0-tetradecanoyl phorbol-13-myristate-acetate or okadaic acid. These observations indicate that OP expression is regulated via an src-mediated protein kinase C signaling pathway. Since it is known that OP mediates osteoclast adherence to the bone matrix, a key event in bone differentiation, our data is most significant in that they strongly suggest that drastic inhibition of synthesis of OP prevents osteoclasts in Src{sup -/-} mice from anchoring to the bone matrix. Consequently, this disruption of osteoclast adherence impairs their ability to form bone-resorbing ruffled border, causing osteopetrosis.« less

Remnant Woven Bone and Calcified Cartilage in Mouse Bone: Differences between Ages/Sex and Effects on Bone Strength

PubMed Central

Ip, Victoria; Toth, Zacharie; Chibnall, John; McBride-Gagyi, Sarah

2016-01-01

Introduction Mouse models are used frequently to study effects of bone diseases and genetic determinates of bone strength. Murine bones have an intracortical band of woven bone that is not present in human bones. This band is not obvious under brightfield imaging and not typically analyzed. Due to the band’s morphology and location it has been theorized to be remnant bone from early in life. Furthermore, lamellar and woven bone are well known to have differing mechanical strengths. The purpose of this study was to determine (i) if the band is from early life and (ii) if the woven bone or calcified cartilage contained within the band affect whole bone strength. Woven Bone Origin Studies In twelve to fourteen week old mice, doxycycline was used to label bone formed prior to 3 weeks old. Doxycycline labeling and woven bone patterns on contralateral femora matched well and encompassed an almost identical cross-sectional area. Also, we highlight for the first time in mice the presence of calcified cartilage exclusively within the band. However, calcified cartilage could not be identified on high resolution cone-beam microCT scans when examined visually or by thresholding methods. Mechanical Strength Studies Subsequently, three-point bending was used to analyze the effects of woven bone and calcified cartilage on whole bone mechanics in a cohort of male and female six and 13 week old Balb/C mice. Three-point bending outcomes were correlated with structural and compositional measures using multivariate linear regression. Woven bone composed a higher percent of young bones than older bones. However, calcified cartilage in older bones was twice that of younger bones, which was similar when normalized by area. Area and/or tissue mineral density accounted for >75% of variation for most strength outcomes. Percent calcified cartilage added significant predictive power to maximal force and bending stress. Calcified cartilage and woven bone could have more influence in genetic models where calcified cartilage percent is double our highest value. PMID:27829059

High calcium to phosphorus ratio impairs growth and bone mineralization in Pekin ducklings.

PubMed

Zhu, Y W; Wen, J; Jiang, X X; Wang, W C; Yang, L

2018-04-01

Two experiments were conducted to investigate the effect of high dietary calcium (Ca) level on growth performance, Ca and phosphorus (P) metabolism, and nutrient utilization in ducklings subjected to normal and low P levels in diets. A completely randomized design was used with a factorial arrangement of 2 total dietary P levels [normal-P (0.60%) and low-P (0.45%) groups] × 4 dietary Ca levels [low-Ca (0.55%), normal-Ca (0.75%), medium-Ca (0.95%) and high-Ca (1.15%) groups)]. Compared to normal-P group, low-P group had lower (P < 0.05) final body weight (BW), average daily gain (ADG), and average daily feed intake (ADFI) and reduced (P < 0.05) serum Ca and P levels, bone Ca, P, and ash content, and bone mineral density in ducklings during the starter period. Under the low-P group, birds from high-Ca group had lower (P < 0.05) final BW, ADG, ADFI, bone ash content, bone mineral density, and the utilization of energy, Ca, and P than those from low-Ca, normal-Ca, and medium-Ca groups. Our results indicate that high-Ca diet induced greater growth suppression and bone mineralization loss in ducklings fed a low-P diet. The aggravated negative effect of high dietary Ca level with a low P level might be related to the elevated serum alkaline phosphatase activity and the reduced utilization of energy, Ca, and P.

The Application of Bone Marrow Transplantation to the Treatment of Genetic Diseases

NASA Astrophysics Data System (ADS)

Parkman, Robertson

1986-06-01

Genetic diseases can be treated by transplantation of either normal allogeneic bone marrow or, potentially, autologous bone marrow into which the normal gene has been inserted in vitro (gene therapy). Histocompatible allogeneic bone marrow transplantation is used for the treatment of genetic diseases whose clinical expression is restricted to lymphoid or hematopoietic cells. The therapeutic role of bone marrow transplantation in the treatment of generalized genetic diseases, especially those affecting the central nervous system, is under investigation. The response of a generalized genetic disease to allogeneic bone marrow transplantation may be predicted by experiments in vitro. Gene therapy can be used only when the gene responsible for the disease has been characterized. Success of gene therapy for a specific genetic disease may be predicted by its clinical response to allogeneic bone marrow transplantation.

Transferrin receptors in human tissues: their distribution and possible clinical relevance.

PubMed

Gatter, K C; Brown, G; Trowbridge, I S; Woolston, R E; Mason, D Y

1983-05-01

The distribution of transferrin receptors (TR) has been studied in a range of normal and malignant tissues using four monoclonal antibodies, BK19.9, B3/25, T56/14 and T58/1. In normal tissues TR was found in a limited number of sites, notably basal epidermis, the endocrine pancreas, hepatocytes, Kupffer cells, testis and pituitary. This restricted pattern of distribution may be relevant to the characteristic pattern of iron deposition in primary haemachromatosis. In contrast to this limited pattern of expression in normal tissue, the receptor was widely distributed in carcinomas, sarcomas and in samples from cases of Hodgkin's disease. This malignancy-associated expression of the receptor may play a role in the anaemia of advanced malignancy by competing with the bone marrow for serum iron.

Transferrin receptors in human tissues: their distribution and possible clinical relevance.

PubMed Central

Gatter, K C; Brown, G; Trowbridge, I S; Woolston, R E; Mason, D Y

1983-01-01

The distribution of transferrin receptors (TR) has been studied in a range of normal and malignant tissues using four monoclonal antibodies, BK19.9, B3/25, T56/14 and T58/1. In normal tissues TR was found in a limited number of sites, notably basal epidermis, the endocrine pancreas, hepatocytes, Kupffer cells, testis and pituitary. This restricted pattern of distribution may be relevant to the characteristic pattern of iron deposition in primary haemachromatosis. In contrast to this limited pattern of expression in normal tissue, the receptor was widely distributed in carcinomas, sarcomas and in samples from cases of Hodgkin's disease. This malignancy-associated expression of the receptor may play a role in the anaemia of advanced malignancy by competing with the bone marrow for serum iron. Images PMID:6302135

Assessment of bone turnover markers and bone mineral density in normal short boys.

PubMed

Gayretli Aydin, Zeynep Gökçe; Bideci, Aysun; Emeksiz, Hamdi C; Çelik, Nurullah; Döğer, Esra; Bukan, Neslihan; Yildiz, Ummügülsüm; Camurdan, Orhun M; Cinaz, Peyami

2015-11-01

To investigate whether there is a change in bone turnover-related biochemical markers and bone mineral density of children with constitutional delay of growth and puberty (CDGP) in the prepubertal period. We measured serum calcium, phosphorus, alkaline phosphatase, parathormone, 25-OH vitamin D, osteocalcin, osteoprotogerin and urinary deoxypyridinoline levels (D-pyd), and bone mineral density (BMD) in 31 prepubertal boys with CDGP. These children were compared with 22 prepubertal boys with familial short stature (FSS) and 27 normal prepubertal boys. Urinary D-pyd was significantly high in CDGP group as compared to control group (p=0.010). Volumetric BMD did not significantly differ between CDGP, FSS, and control groups (p=0.450). Volumetric BMD and urinary D-pyd levels of FSS and control groups were similar. Mean or median levels of calcium, phosphorus, alkaline phosphatase, parathormone, and osteoprotegerin did not significantly differ between CDGP, FSS, and control groups. Our data suggest that prepubertal boys with CDPG have normal bone turnover. However, their significantly higher urinary D-pyd levels relative to those of FSS and control groups might be an indicator of later development of osteoporosis. Therefore, long-term follow-up studies monitoring bone mineral status of prepubertal boys with CDPG from prepuberty to adulthood are needed to better understand bone metabolism of these patients.

Sex Determination by Biometry of Anterior Features of Human Hip Bones in South Indian Population.

PubMed

Rajasekhar, Sssn; Vasudha, T K; Aravindhan, K

2017-06-01

Sex determination is the first step in establishing the identity of skeletal remains. Many studies included biometry of posterior features of hip bone. Very few studies are reported involving the biometry of anterior features of the hip bone. Anterior features of hip bone are important especially, if there is damage to the posterior features of hip bone in cases involving deliberate disfigurement of the body to resist identification of the crime in medicolegal cases. The present study was done to evaluate the effectiveness of anterior border parameters of the hip bone for prediction of sex using discriminant function analysis in South Indian population. A total of 206 dry bones were used (121 male and 85 female) and parameters like the distance between pubic tubercle and anterior rim of acetabulum, vertical acetabular diameter, transverse acetabular diameter, and the distance between pubic tubercle to highest point on the iliopubic eminence were measured using Vernier calipers. Normally distributed variables were compared using Students t-test to analyse the significance. There was significant difference between the male and female hip bones of the observed variables with p-value less than 0.05. In parameters like the distance between pubic tubercle to anterior rim of acetabulum and distance between the highest points on iliopubic eminence to pubic tubercle; the values were more in female when compared to males. In parameters like vertical and transverse acetabular diameters; the values in males were more when compared to females. These parameters of hip bone can be utilised for sex determination in South Indian population.

Daily intermittent decreases in serum levels of parathyroid hormone have an anabolic-like action on the bones of uremic rats with low-turnover bone and osteomalacia.

PubMed

Ishii, H; Wada, M; Furuya, Y; Nagano, N; Nemeth, E F; Fox, J

2000-02-01

The calcium receptor agonist (calcimimetic) compound NPS R-568 causes rapid decreases in circulating levels of parathyroid hormone (PTH) in rats and humans. We hypothesized that daily intermittent decreases in serum PTH levels may have different effects on bone than do chronically sustained decreases. To test this hypothesis, we compared two NPS R-568 dosing regimens in rats with chronic renal insufficiency induced by two intravenous injections of adriamycin. Fourteen weeks after the second adriamycin injection, creatinine clearance was reduced by 52%, PTH levels were elevated approximately 2.5-fold, and serum 25(OH)D3 and 1,25(OH)2D3 levels were reduced substantially. Treatment by daily per os gavage, which decreased PTH levels intermittently, or continuous subcutaneous infusion, which resulted in a sustained suppression of serum PTH levels, then began for 8 weeks. Despite the hyperparathyroidism, the adriamycin-injected rats developed a low-turnover bone lesion with osteomalacia (fourfold increase in osteoid volume in the proximal tibial metaphysis) and osteopenia (67% decrease in cancellous bone volume and an 18% reduction in bone mineral density at the distal femur). Daily administered (but not infused) NPS R-568 significantly increased cancellous bone volume solely by normalizing trabecular thickness, and increased femoral bone mineral density by 14%. These results indicate that daily intermittent, but not sustained, decreases in PTH levels have an "anabolic-like" effect on bones with a low-turnover lesion in this animal model of chronic renal insufficiency.

Peripheral cannabinoid receptor, CB2, regulates bone mass

PubMed Central

Ofek, Orr; Karsak, Meliha; Leclerc, Nathalie; Fogel, Meirav; Frenkel, Baruch; Wright, Karen; Tam, Joseph; Attar-Namdar, Malka; Kram, Vardit; Shohami, Esther; Mechoulam, Raphael; Zimmer, Andreas; Bab, Itai

2006-01-01

The endogenous cannabinoids bind to and activate two G protein-coupled receptors, the predominantly central cannabinoid receptor type 1 (CB1) and peripheral cannabinoid receptor type 2 (CB2). Whereas CB1 mediates the cannabinoid psychotropic, analgesic, and orectic effects, CB2 has been implicated recently in the regulation of liver fibrosis and atherosclerosis. Here we show that CB2-deficient mice have a markedly accelerated age-related trabecular bone loss and cortical expansion, although cortical thickness remains unaltered. These changes are reminiscent of human osteoporosis and may result from differential regulation of trabecular and cortical bone remodeling. The CB2–/– phenotype is also characterized by increased activity of trabecular osteoblasts (bone-forming cells), increased osteoclast (the bone-resorbing cell) number, and a markedly decreased number of diaphyseal osteoblast precursors. CB2 is expressed in osteoblasts, osteocytes, and osteoclasts. A CB2-specific agonist that does not have any psychotropic effects enhances endocortical osteoblast number and activity and restrains trabecular osteoclastogenesis, apparently by inhibiting proliferation of osteoclast precursors and receptor activator of NF-κB ligand expression in bone marrow-derived osteoblasts/stromal cells. The same agonist attenuates ovariectomy-induced bone loss and markedly stimulates cortical thickness through the respective suppression of osteoclast number and stimulation of endocortical bone formation. These results demonstrate that the endocannabinoid system is essential for the maintenance of normal bone mass by osteoblastic and osteoclastic CB2 signaling. Hence, CB2 offers a molecular target for the diagnosis and treatment of osteoporosis, the most prevalent degenerative disease in developed countries. PMID:16407142

Vitamin A Is a Negative Regulator of Osteoblast Mineralization

PubMed Central

Hu, Lijuan; Pejler, Gunnar; Andersson, Göran; Jacobson, Annica; Melhus, Håkan

2013-01-01

An excessive intake of vitamin A has been associated with an increased risk of fractures in humans. In animals, a high vitamin A intake leads to a reduction of long bone diameter and spontaneous fractures. Studies in rodents indicate that the bone thinning is due to increased periosteal bone resorption and reduced radial growth. Whether the latter is a consequence of direct effects on bone or indirect effects on appetite and general growth is unknown. In this study we therefore used pair-feeding and dynamic histomorphometry to investigate the direct effect of a high intake of vitamin A on bone formation in rats. Although there were no differences in body weight or femur length compared to controls, there was an approximately halved bone formation and mineral apposition rate at the femur diaphysis of rats fed vitamin A. To try to clarify the mechanism(s) behind this reduction, we treated primary human osteoblasts and a murine preosteoblastic cell line (MC3T3-E1) with the active metabolite of vitamin A; retinoic acid (RA), a retinoic acid receptor (RAR) antagonist (AGN194310), and a Cyp26 inhibitor (R115866) which blocks endogenous RA catabolism. We found that RA, via RARs, suppressed in vitro mineralization. This was independent of a negative effect on osteoblast proliferation. Alkaline phosphatase and bone gamma carboxyglutamate protein (Bglap, Osteocalcin) were drastically reduced in RA treated cells and RA also reduced the protein levels of Runx2 and Osterix, key transcription factors for progression to a mature osteoblast. Normal osteoblast differentiation involved up regulation of Cyp26b1, the major enzyme responsible for RA degradation, suggesting that a drop in RA signaling is required for osteogenesis analogous to what has been found for chondrogenesis. In addition, RA decreased Phex, an osteoblast/osteocyte protein necessary for mineralization. Taken together, our data indicate that vitamin A is a negative regulator of osteoblast mineralization. PMID:24340023

Growth hormone and bone health.

PubMed

Bex, Marie; Bouillon, Roger

2003-01-01

Growth hormone (GH) and insulin-like growth factor-I have major effects on growth plate chondrocytes and all bone cells. Untreated childhood-onset GH deficiency (GHD) markedly impairs linear growth as well as three-dimensional bone size. Adult peak bone mass is therefore about 50% that of adults with normal height. This is mainly an effect on bone volume, whereas true bone mineral density (BMD; g/cm(3)) is virtually normal, as demonstrated in a large cohort of untreated Russian adults with childhood-onset GHD. The prevalence of fractures in these untreated childhood-onset GHD adults was, however, markedly and significantly increased in comparison with normal Russian adults. This clearly indicates that bone mass and bone size matter more than true bone density. Adequate treatment with GH can largely correct bone size and in several studies also bone mass, but it usually requires more than 5 years of continuous treatment. Adult-onset GHD decreases bone turnover and results in a mild deficit, generally between -0.5 and -1.0 z-score, in bone mineral content and BMD of the lumbar spine, radius and femoral neck. Cross-sectional surveys and the KIMS data suggest an increased incidence of fractures. GH replacement therapy increases bone turnover. The three controlled studies with follow-up periods of 18 and 24 months demonstrated a modest increase in BMD of the lumbar spine and femoral neck in male adults with adult-onset GHD, whereas no significant changes in BMD were observed in women. GHD, whether childhood- or adult-onset, impairs bone mass and strength. Appropriate substitution therapy can largely correct these deficiencies if given over a prolonged period. GH therapy for other bone disorders not associated with primary GHD needs further study but may well be beneficial because of its positive effects on the bone remodelling cycle. Copyright 2003 S. Karger AG, Basel

Skeletal unloading causes resistance of osteoprogenitor cells to parathyroid hormone and to insulin-like growth factor-I

NASA Technical Reports Server (NTRS)

Kostenuik, P. J.; Harris, J.; Halloran, B. P.; Turner, R. T.; Morey-Holton, E. R.; Bikle, D. D.

1999-01-01

Skeletal unloading decreases bone formation and osteoblast number in vivo and decreases the number and proliferation of bone marrow osteoprogenitor (BMOp) cells in vitro. We tested the ability of parathyroid hormone (PTH) to stimulate BMOp cells in vivo by treating Sprague Dawley rats (n = 32) with intermittent PTH(1-34) (1 h/day at 8 microg/100 g of body weight), or with vehicle via osmotic minipumps during 7 days of normal weight bearing or hind limb unloading. Marrow cells were flushed from the femur and cultured at the same initial density for up to 21 days. PTH treatment of normally loaded rats caused a 2.5-fold increase in the number of BMOp cells, with similar increases in alkaline phosphatase (ALP) activity and mineralization, compared with cultures from vehicle-treated rats. PTH treatment of hind limb unloaded rats failed to stimulate BMOp cell number, ALP activity, or mineralization. Hind limb unloading had no significant effect on PTH receptor mRNA or protein levels in the tibia. Direct in vitro PTH challenge of BMOp cells isolated from normally loaded bone failed to stimulate their proliferation and inhibited their differentiation, suggesting that the in vivo anabolic effect of intermittent PTH on BMOp cells was mediated indirectly by a PTH-induced factor. We hypothesize that this factor is insulin-like growth factor-I (IGF-I), which stimulated the in vitro proliferation and differentiation of BMOp cells isolated from normally loaded bone, but not from unloaded bone. These results suggest that IGF-I mediates the ability of PTH to stimulate BMOp cell proliferation in normally loaded bone, and that BMOp cells in unloaded bone are resistant to the anabolic effect of intermittent PTH therapy due to their resistance to IGF-I.

Maternal Perinatal Diet Induces Developmental Programming of Bone Architecture

PubMed Central

Devlin, MJ; Grasemann, C; Cloutier, AM; Louis, L; Alm, C; Palmert, MR; Bouxsein, ML

2013-01-01

Maternal high fat diet can alter offspring metabolism via perinatal developmental programming. This study tests the hypothesis that maternal high fat diet also induces perinatal programming of offspring bone mass and strength. We compared skeletal acquisition in pups from C57Bl/6J mice fed high fat or normal diet from preconception through lactation. Three-week-old male and female pups from high fat (HF-N) and normal mothers (N-N) were weaned onto normal diet. Outcomes at 14 and 26 wks of age included body mass, body composition, whole body bone mineral content via pDXA, femoral cortical and trabecular architecture via μCT, and glucose tolerance. Female HF-N had normal body mass and glucose tolerance, with lower %body fat but higher serum leptin at 14 wks vs. N-N (p<0.05 for both). Whole body bone mineral content was 12% lower at 14 wks and 5% lower at 26 wks, but trabecular bone volume fraction was 20% higher at 14 wks in female HF-N vs. N-N (p<0.05 for all). Male HF-N had normal body mass and mildly impaired glucose tolerance, with lower %body fat at 14 wks and lower serum leptin at 26 wks vs. N-N (p<0.05 for both). Serum insulin was higher at 14 wks and lower at 26 wks in HF-N vs. N-N (p<0.05). Trabecular BV/TV was 34% higher and cortical bone area was 6% higher at 14 wks vs. N-N (p<0.05 for both). These data suggest maternal high fat diet has complex effects on offspring bone, supporting the hypothesis that maternal diet alters postnatal skeletal homeostasis. PMID:23503967

Osteoarthritis

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HES1, a target of Notch signaling, is elevated in canine osteosarcoma, but reduced in the most aggressive tumors.

PubMed

Dailey, Deanna D; Anfinsen, Kristin P; Pfaff, Liza E; Ehrhart, E J; Charles, J Brad; Bønsdorff, Tina B; Thamm, Douglas H; Powers, Barbara E; Jonasdottir, Thora J; Duval, Dawn L

2013-07-01

Hairy and enhancer of split 1 (HES1), a basic helix-loop-helix transcriptional repressor, is a downstream target of Notch signaling. Notch signaling and HES1 expression have been linked to growth and survival in a variety of human cancer types and have been associated with increased metastasis and invasiveness in human osteosarcoma cell lines. Osteosarcoma (OSA) is an aggressive cancer demonstrating both high metastatic rate and chemotherapeutic resistance. The current study examined expression of Notch signaling mediators in primary canine OSA tumors and canine and human osteosarcoma cell lines to assess their role in OSA development and progression. Reverse transcriptase - quantitative PCR (RT-qPCR) was utilized to quantify HES1, HEY1, NOTCH1 and NOTCH2 gene expression in matched tumor and normal metaphyseal bone samples taken from dogs treated for appendicular OSA at the Colorado State University Veterinary Teaching Hospital. Gene expression was also assessed in tumors from dogs with a disease free interval (DFI) of <100 days compared to those with a DFI > 300 days following treatment with surgical amputation followed by standard chemotherapy. Immunohistochemistry was performed to confirm expression of HES1. Data from RT-qPCR and immunohistochemical (IHC) experiments were analyzed using REST2009 software and survival analysis based on IHC expression employed the Kaplan-Meier method and log rank analysis. Unbiased clustered images were generated from gene array analysis data for Notch/HES1 associated genes. Gene array analysis of Notch/HES1 associated genes suggested alterations in the Notch signaling pathway may contribute to the development of canine OSA. HES1 mRNA expression was elevated in tumor samples relative to normal bone, but decreased in tumor samples from dogs with a DFI < 100 days relative to those with a DFI > 300 days. NOTCH2 and HEY1 mRNA expression was also elevated in tumors relative to normal bone, but was not differentially expressed between the DFI tumor groups. Survival analysis confirmed an association between decreased HES1 immunosignal and shorter DFI. Our findings suggest that activation of Notch signaling occurs and may contribute to the development of canine OSA. However, association of low HES1 expression and shorter DFI suggests that mechanisms that do not alter HES1 expression may drive the most aggressive tumors.

Ectopic Hard Tissue Formation by Odonto/Osteogenically In Vitro Differentiated Human Deciduous Teeth Pulp Stem Cells.

PubMed

Kim, Seunghye; Song, Je Seon; Jeon, Mijeong; Shin, Dong Min; Kim, Seong-Oh; Lee, Jae Ho

2015-07-01

There have been many attempts to use the pulp tissue from human deciduous teeth for dentin or bone regeneration. The objective of this study was to determine the effects of odonto/osteogenic in vitro differentiation of deciduous teeth pulp stem cells (DTSCs) on their in vivo hard tissue-forming potential. DTSCs were isolated from extracted deciduous teeth using the outgrowth method. These cells were exposed to odonto/osteogenic stimuli for 4 and 8 days (Day 4 and Day 8 groups, respectively), while cells in the control group were cultured in normal medium. The in vitro differentiated DTSCs and the control DTSCs were transplanted subcutaneously into immunocompromised mice with macroporous biphasic calcium phosphate and sacrificed at 8 weeks post-implantation. The effect of odonto/osteogenic in vitro differentiation was evaluated using alkaline phosphatase (ALP) staining and quantitative reverse transcription polymerase chain reaction (RT-PCR). The in vivo effect was evaluated by qualitative RT-PCR, assessment of ALP activity, histologic analysis, and immunohistochemical staining. The amount of hard tissue was greater in Day 4 group than Day 8 group (p = 0.014). However, Day 8 group generated lamellar bone-like structure, which was immunonegative to anti-human dentin sialoprotein with significantly low expression level of DSPP compared with the control group (p = 0.008). This study demonstrates that odonto/osteogenic in vitro differentiation of DTSCs enhances the formation of bone-like tissue, instead of dentin-like tissue, when transplanted subcutaneously using MBCP as a carrier. The odonto/osteogenic in vitro differentiation of DTSCs may be an effective modification that enhances in vivo bone formation by DTSCs.

Povidone-Iodine Has a Profound Effect on In Vitro Osteoblast Proliferation and Metabolic Function and Inhibits Their Ability to Mineralize and Form Bone.

PubMed

Newton Ede, Matthew P; Philp, Ashleigh M; Philp, Andrew; Richardson, Stephen M; Mohammad, Saeed; Jones, Simon W

2016-05-01

A study examining the clinical protocol of scoliosis wound irrigation, demonstrating povidone-iodine's (PVI) effect on human osteoblast cells. Primary and immortal cell line osteoblasts were treated with 0.35% PVI for 3 minutes, and analyzed for proliferation rate, oxidative capacity, and mineralization. To model spinal wound irrigation with dilute PVI in vitro, in order to investigate the effect of PVI on osteoblast proliferation, metabolism, and bone mineralization. Previously PVI irrigation has been proposed as a safe and effective practice to avoid bacterial growth after spinal surgery. However, recent evidence in multiple cell types suggests that PVI has a deleterious effect on cellular viability and cellular function. Primary and immortal human osteoblast cells were exposed to either phosphate buffered saline control or with 0.35% PVI for 3 minutes. Cellular proliferation was measured over the duration of 7 days by MTS assay. Oxygen consumption rate, extracellular acidification rate, and proton production rate were analyzed using a Seahorse XF24 Bioanalyzer. Protein expression of the electron transport chain subunits CII-SDHB, CIII-UQRCR2, and CV-ATP5A was measured via Western blotting. Mineralized bone nodules were stained with alizarin red. Expressed as a percentage of normal osteoblast proliferation, osteoblasts exposed to 0.35% PVI exhibited a significant 24% decrease in proliferation after 24 hours. This was a sustained response, resulting in a 72% decline in cellular proliferation at 1 week. There was a significant reduction in oxygen consumption rate, extracellular acidification rate, and proton production rate (P < 0.05), in osteoblasts that had been exposed to 0.35% PVI for 3 minutes, coupled with a marked reduction in the protein expression of CII-SDHB. Osteoblasts exposed to 0.35% PVI exhibited reduced bone nodule mineralization compared to control phosphate buffered saline exposed osteoblasts (P < 0.01). PVI has a rapid and detrimental effect on human osteoblast cellular proliferation, metabolic function, and bone nodule mineralization. NA.

An in vitro study of adherence of coagulase-negative staphylococci to bone chip columns.

PubMed

Lazarovich, Zilia; Boldur, Ida; Reifer, Rachel; Nitzan, Yeshayahu

2006-09-01

Coagulase-negative staphylococci (CNS) have become a dominant cause of bone infections and their adherence to the infected bones is a prerequisite for the initiation of these infections. In the present study we investigated and compared the adherence of CNS bacteria to human, chicken and rabbit bones. The study was performed using columns made of bone powder from the three different sources, and measurement of the extent of adhesion to bones of CNS bacteria as an in vitro model which is based on particles of matrix that are closely related to the natural matrix. The adhesion to rabbit bone was relatively high, while adhesion to both human and chicken bone columns was lower and almost identical. Pretreatment of the CNS bacteria with sodium periodate, beta-galactosidase or proteinase K significantly inhibited by 50-60% the adhesion to human bones. Pretreatment of CNS bacteria with subinhibitory concentrations of vancomycin or tunicamycin increased their adherence to human bones several-fold. When the bones were pretreated with vancomycin a considerable increase in the adhesion rate of the bacteria to human and chicken bones was seen. A smaller increase in adherence was observed after pretreatment of human bones with the antibiotic tunicamycin. Salicylic acid or benzalkonium chloride (BZC) also resulted in an increase in adhesion to these pretreated bones. From the results obtained it seems that pretreatment of the CNS bacteria with certain reagents exposes adhesins on the surface of the CNS bacteria. On the other hand, pretreatment of the bones with other reagents may enable a better exposure of receptors located on the bone cells and, as a consequence, may improve the adhesion of the CNS bacteria to the treated bones.

The Relevance of Mouse Models for Investigating Age-Related Bone Loss in Humans

PubMed Central

2013-01-01

Mice are increasingly used for investigation of the pathophysiology of osteoporosis because their genome is easily manipulated, and their skeleton is similar to that of humans. Unlike the human skeleton, however, the murine skeleton continues to grow slowly after puberty and lacks osteonal remodeling of cortical bone. Yet, like humans, mice exhibit loss of cancellous bone, thinning of cortical bone, and increased cortical porosity with advancing age. Histologic evidence in mice and humans alike indicates that inadequate osteoblast-mediated refilling of resorption cavities created during bone remodeling is responsible. Mouse models of progeria also show bone loss and skeletal defects associated with senescence of early osteoblast progenitors. Additionally, mouse models of atherosclerosis, which often occurs in osteoporotic participants, also suffer bone loss, suggesting that common diseases of aging share pathophysiological pathways. Knowledge of the causes of skeletal fragility in mice should therefore be applicable to humans if inherent limitations are recognized. PMID:23689830

How long bones grow children: Mechanistic paths to variation in human height growth.

PubMed

Lampl, Michelle; Schoen, Meriah

2017-03-01

Eveleth and Tanner's descriptive documentation of worldwide variability in human growth provided evidence of the interaction between genetics and environment during development that has been foundational to the science of human growth. There remains a need, however, to describe the mechanistic foundations of variability in human height growth patterns. A review of research documenting cellular activities at the endochondral growth plate aims to show how the unique microenvironment and cell functions during the sequential phases of the chondrocyte lifecycle affect long bone elongation, a fundamental source of height growth. There are critical junctures within the chondrocytic differentiation cascade at which environmental influences are integrated and have the ability to influence progression to the hypertrophic chondrocyte phase, the primary driver of long bone elongation. Phenotypic differences in height growth patterns reflect variability in amplitude and frequency of discretely timed hypertrophic cellular expansion events, the cellular basis of saltation and stasis growth biology. Final height is a summary of the dynamic processes carried out by the growth plate cellular machinery. As these cell-level mechanisms unfold in an individual, time-specific manner, there are many critical points at which a genetic growth program can be enhanced or perturbed. Recognizing both the complexity and fluidity of this adaptive system questions the likelihood of a single, optimal growth pattern and instead identifies a larger bandwidth of saltatory frequencies for "normal" growth. Further inquiry into mechanistic sources of variability acting at critical organizational points of chondrogenesis can provide new opportunities for growth interventions. © 2017 Wiley Periodicals, Inc.

Chemical disposition of boron in animals and humans.

PubMed Central

Moseman, R F

1994-01-01

Elemental boron was isolated in 1808. It typically occurs in nature as borates hydrated with varying amounts of water. Important compounds are boric acid and borax. Boron compounds are also used in the production of metals, enamels, and glasses. In trace amounts, boron is essential for the growth of many plants, and is found in animal and human tissues at low concentrations. Poisoning in humans has been reported as the result of accidental ingestion or use of large amounts in the treatment of burns. Boron as boric acid is fairly rapidly absorbed and excreted from the body via urine. The half-life of boric acid in humans is on the order of 1 day. Boron does not appear to accumulate in soft tissues of animals, but does accumulate in bone. Normal levels of boron in soft tissues, urine, and blood generally range from less than 0.05 ppm to no more than 10 ppm. In poisoning incidents, the amount of boric acid in brain and liver tissue has been reported to be as high as 2000 ppm. Recent studies at the National Institute of Environmental Health Sciences have indicated that boron may contribute to reduced fertility in male rodents fed 9000 ppm of boric acid in feed. Within a few days, boron levels in blood and most soft tissues quickly reached a plateau of about 15 ppm. Boron in bone did not appear to plateau, reaching 47 ppm after 7 days on the diet. Cessation of exposure to dietary boron resulted in a rapid drop in bone boron.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7889870

Intracochlear pressure measurements to study bone conduction transmission: State-of-the art and proof of concept of the experimental Procedure

NASA Astrophysics Data System (ADS)

Borgers, Charlotte; van Wieringen, Astrid; D'hondt, Christiane; Verhaert, Nicolas

2018-05-01

The cochlea is the main contributor in bone conduction perception. Measurements of differential pressure in the cochlea give a good estimation of the cochlear input provided by bone conduction stimulation. Recent studies have proven the feasibility of intracochlear pressure measurements in chinchillas and in human temporal bones to study bone conduction. However, similar measurements in fresh-frozen whole human cadaveric heads could give a more realistic representation of the five different transmission pathways of bone conduction to the cochlea compared to human temporal bones. The aim of our study is to develop and validate a framework for intracochlear pressure measurements to evaluate different aspects of bone conduction in whole human cadaveric heads. A proof of concept describing our experimental setup is provided together with the procedure. Additionally, we also present a method to fix the stapes footplate in order to simulate otosclerosis in human temporal bones. The effectiveness of this method is verified by some preliminary results.

Forward Genetics Defines Xylt1 as a Key, Conserved Regulator of Early Chondrocyte Maturation and Skeletal Length

PubMed Central

Mis, Emily K.; Liem, Karel F.; Kong, Yong; Schwartz, Nancy B.; Domowicz, Miriam; Weatherbee, Scott D.

2014-01-01

The long bones of the vertebrate body are built by the initial formation of a cartilage template that is later replaced by mineralized bone. The proliferation and maturation of the skeletal precursor cells (chondrocytes) within the cartilage template and their replacement by bone is a highly coordinated process which, if misregulated, can lead to a number of defects including dwarfism and other skeletal deformities. This is exemplified by the fact that abnormal bone development is one of the most common types of human birth defects. Yet, many of the factors that initiate and regulate chondrocyte maturation are not known. We identified a recessive dwarf mouse mutant (pug) from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. pug mutant skeletal elements are patterned normally during development, but display a ~20% length reduction compared to wild-type embryos. We show that the pug mutation does not lead to changes in chondrocyte proliferation but instead promotes premature maturation and early ossification, which ultimately leads to disproportionate dwarfism. Using sequence capture and high-throughput sequencing, we identified a missense mutation in the Xylosyltransferase 1 (Xylt1) gene in pug mutants. Xylosyltransferases catalyze the initial step in glycosaminoglycan (GAG) chain addition to proteoglycan core proteins, and these modifications are essential for normal proteoglycan function. We show that the pug mutation disrupts Xylt1 activity and subcellular localization, leading to a reduction in GAG chains in pug mutants. The pug mutant serves as a novel model for mammalian dwarfism and identifies a key role for proteoglycan modification in the initiation of chondrocyte maturation. PMID:24161523

An in vitro 3D bone metastasis model by using a human bone tissue culture and human sex-related cancer cells.

PubMed

Salamanna, Francesca; Borsari, Veronica; Brogini, Silvia; Giavaresi, Gianluca; Parrilli, Annapaola; Cepollaro, Simona; Cadossi, Matteo; Martini, Lucia; Mazzotti, Antonio; Fini, Milena

2016-11-22

One of the main limitations, when studying cancer-bone metastasis, is the complex nature of the native bone environment and the lack of reliable, simple, inexpensive models that closely mimic the biological processes occurring in patients and allowing the correct translation of results. To enhance the understanding of the mechanisms underlying human bone metastases and in order to find new therapies, we developed an in vitro three-dimensional (3D) cancer-bone metastasis model by culturing human breast or prostate cancer cells with human bone tissue isolated from female and male patients, respectively. Bone tissue discarded from total hip replacement surgery was cultured in a rolling apparatus system in a normoxic or hypoxic environment. Gene expression profile, protein levels, histological, immunohistochemical and four-dimensional (4D) micro-CT analyses showed a noticeable specificity of breast and prostate cancer cells for bone colonization and ingrowth, thus highlighting the species-specific and sex-specific osteotropism and the need to widen the current knowledge on cancer-bone metastasis spread in human bone tissues. The results of this study support the application of this model in preclinical studies on bone metastases and also follow the 3R principles, the guiding principles, aimed at replacing/reducing/refining (3R) animal use and their suffering for scientific purposes.

An in vitro 3D bone metastasis model by using a human bone tissue culture and human sex-related cancer cells

PubMed Central

Salamanna, Francesca; Borsari, Veronica; Brogini, Silvia; Giavaresi, Gianluca; Parrilli, Annapaola; Cepollaro, Simona; Cadossi, Matteo; Martini, Lucia; Mazzotti, Antonio; Fini, Milena

2016-01-01

One of the main limitations, when studying cancer-bone metastasis, is the complex nature of the native bone environment and the lack of reliable, simple, inexpensive models that closely mimic the biological processes occurring in patients and allowing the correct translation of results. To enhance the understanding of the mechanisms underlying human bone metastases and in order to find new therapies, we developed an in vitro three-dimensional (3D) cancer-bone metastasis model by culturing human breast or prostate cancer cells with human bone tissue isolated from female and male patients, respectively. Bone tissue discarded from total hip replacement surgery was cultured in a rolling apparatus system in a normoxic or hypoxic environment. Gene expression profile, protein levels, histological, immunohistochemical and four-dimensional (4D) micro-CT analyses showed a noticeable specificity of breast and prostate cancer cells for bone colonization and ingrowth, thus highlighting the species-specific and sex-specific osteotropism and the need to widen the current knowledge on cancer-bone metastasis spread in human bone tissues. The results of this study support the application of this model in preclinical studies on bone metastases and also follow the 3R principles, the guiding principles, aimed at replacing/reducing/refining (3R) animal use and their suffering for scientific purposes. PMID:27765913

[Characteristics of bone tissue of rats after flight aboard biosputnik Kosmos-1129].

PubMed

Rogacheva, I V; Stupakov, G P; Volozhin, A I; Pavlova, M N; Poliakov, A N

1984-01-01

Bones of rats flown for 19 days onboard Cosmos-1129 were examined. The examination included bone mass, density, mineral composition, reconstruction parameters, and elemental composition at R + 1, R + 6, and R + 29. After flight the rats developed osteoporosis in the spongy structures of tubular bones and a smaller thickness of the cortical layer of the diaphysis; they showed no mineralization of the microstructures, a slight decrease of the Ca concentration, and a normal content of P. At R + 6 these changes progressively developed and at R + 29 they returned to normal.

Matrix Vesicle Enzyme Activity and Phospholipid Content in Endosteal Bone Following Implantation of Osseointegrating and Non-Osseointegrating Implant Materials.

DTIC Science & Technology

1992-01-01

limb. The collected hemopoietic material was a combination of cells, fractured cell debris, and matrix vesicles. This material was utilized for the... dogs and rabbits (Deutscher et al., 1978; Fuchs et al., 1981), and the mandibles of humans (Bunte et al., 1977). Following surgical implantation, there...associated with mineralization in a number of additional normal and pathologic conditions, including cementum (Hayashi, 1985), fracture callus (Boskey et al

Depletion of stromal cells expressing fibroblast activation protein-α from skeletal muscle and bone marrow results in cachexia and anemia

PubMed Central

Roberts, Edward W.; Deonarine, Andrew; Jones, James O.; Denton, Alice E.; Feig, Christine; Lyons, Scott K.; Espeli, Marion; Kraman, Matthew; McKenna, Brendan; Wells, Richard J.B.; Zhao, Qi; Caballero, Otavia L.; Larder, Rachel; Coll, Anthony P.; O’Rahilly, Stephen; Brindle, Kevin M.; Teichmann, Sarah A.; Tuveson, David A.

2013-01-01

Fibroblast activation protein-α (FAP) identifies stromal cells of mesenchymal origin in human cancers and chronic inflammatory lesions. In mouse models of cancer, they have been shown to be immune suppressive, but studies of their occurrence and function in normal tissues have been limited. With a transgenic mouse line permitting the bioluminescent imaging of FAP+ cells, we find that they reside in most tissues of the adult mouse. FAP+ cells from three sites, skeletal muscle, adipose tissue, and pancreas, have highly similar transcriptomes, suggesting a shared lineage. FAP+ cells of skeletal muscle are the major local source of follistatin, and in bone marrow they express Cxcl12 and KitL. Experimental ablation of these cells causes loss of muscle mass and a reduction of B-lymphopoiesis and erythropoiesis, revealing their essential functions in maintaining normal muscle mass and hematopoiesis, respectively. Remarkably, these cells are altered at these sites in transplantable and spontaneous mouse models of cancer-induced cachexia and anemia. Thus, the FAP+ stromal cell may have roles in two adverse consequences of cancer: their acquisition by tumors may cause failure of immunosurveillance, and their alteration in normal tissues contributes to the paraneoplastic syndromes of cachexia and anemia. PMID:23712428

Differentiation of macrophages from normal human bone marrow in liquid culture. Electron microscopy and cytochemistry.

PubMed Central

Bainton, D R; Golde, D W

1978-01-01

To study the various stages of human mononuclear phagocyte maturation, we cultivated bone marrow in an in vitro diffusion chamber with the cells growing in suspension and upon a dialysis membrane. At 2, 7, and 14 days, the cultured cells were examined by electron microscopy and cytochemical techniques for peroxidase and for more limited analysis of acid phosphatase and arylsulfatase. Peroxidase was being synthesized in promonocytes of 2- and 7-day cultures, as evidenced by reaction product in the rough-surfaced endoplasmic reticulum, Golgi complex, and storage granules. Peroxidase synthesis had ceased in monocytes and the enzyme appeared only in some granules. By 7 days, large macrophages predominated, containing numerous peroxidase-positive storage granules, and heterophagy of dying cells was evident. By 14 days, the most prevalent cell type was the large peroxidase-negative macrophage. Thus, peroxidase is present in high concentrations in immature cells but absent at later stages, presumably a result of degranulation of peroxidase-positive storage granules. Clusters of peroxidase-negative macrophages with indistinct borders (epithelioid cells), as well as obvious multinucleated giant cells, were noted. Frequently, the interdigitating plasma membranes of neighboring macrophages showed a modification resembling a septate junction--to our knowledge, representing the first documentation of this specialized cell contact between normal macrophages. We suggest that such junctions may serve as zones of adhesion between epithelioid cells. Images PMID:659615

Derangement of calcium metabolism in diabetes mellitus: negative outcome from the synergy between impaired bone turnover and intestinal calcium absorption.

PubMed

Wongdee, Kannikar; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

2017-01-01

Both types 1 and 2 diabetes mellitus (T1DM and T2DM) are associated with profound deterioration of calcium and bone metabolism, partly from impaired intestinal calcium absorption, leading to a reduction in calcium uptake into the body. T1DM is associated with low bone mineral density (BMD) and osteoporosis, whereas the skeletal changes in T2DM are variable, ranging from normal to increased and to decreased BMD. However, both types of DM eventually compromise bone quality through production of advanced glycation end products and misalignment of collagen fibrils (so-called matrix failure), thereby culminating in a reduction of bone strength. The underlying cellular mechanisms (cellular failure) are related to suppression of osteoblast-induced bone formation and bone calcium accretion, as well as to enhancement of osteoclast-induced bone resorption. Several other T2DM-related pathophysiological changes, e.g., osteoblast insulin resistance, impaired productions of osteogenic growth factors (particularly insulin-like growth factor 1 and bone morphogenetic proteins), overproduction of pro-inflammatory cytokines, hyperglycemia, and dyslipidemia, also aggravate diabetic osteopathy. In the kidney, DM and the resultant hyperglycemia lead to calciuresis and hypercalciuria in both humans and rodents. Furthermore, DM causes deranged functions of endocrine factors related to mineral metabolism, e.g., parathyroid hormone, 1,25-dihydroxyvitamin D 3 , and fibroblast growth factor-23. Despite the wealth of information regarding impaired bone remodeling in DM, the long-lasting effects of DM on calcium metabolism in young growing individuals, pregnant women, and neonates born to women with gestational DM have received scant attention, and their underlying mechanisms are almost unknown and worth exploring.

An assessment of exposure to rare earth elements among patients receiving long-term parenteral nutrition.

PubMed

Galusha, Aubrey L; Kruger, Pamela C; Howard, Lyn J; Parsons, Patrick J

2018-05-01

Patients receiving long-term parenteral nutrition (PN) are exposed to potentially toxic elements, which may accumulate in bone. Bone samples collected from seven PN patients (average = 14 years) and eighteen hip/knee samples were analyzed for Al as part of a previous investigation. Yttrium was serendipitously detected in the PN bone samples, leading to the present investigation of rare earth elements (REEs). A method for quantitating fifteen REEs in digested bone was developed based on tandem ICP-MS (ICP-MS/MS) to resolve spectral interferences. The method was validated against nine biological reference materials (RMs) for which assigned values were available for most REEs. Values found in two NIST bone SRMs (1400 Bone Ash and 1486 Bone Meal) compared favorably to those reported elsewhere. Method detection limits ranged from 0.9 ng g -1 (Tm) to 5.8 ng g -1 (Y). Median REE values in the PN patient group were at least fifteen times higher than the "control" group, and exceeded all previously reported data for eleven REEs in human bones. REE content in PN bones normalized to the Earth's upper crust revealed anomalies for Gd in two patients, likely from exposure to Gd-containing contrast agents used in MRI studies. A retrospective review of the medical record for one patient revealed an almost certain case of nephrogenic systemic fibrosis, associated with Gd exposure. Analysis of two current PN formulations showed traces of REEs with relative abundances similar to those found in the PN bones, providing convincing evidence that PN solutions were the primary source of REEs in this population. Copyright © 2018 Elsevier GmbH. All rights reserved.

Localization of congenital tegmen tympani defects.

PubMed

Tóth, Miklós; Helling, Kai; Baksa, Gábor; Mann, Wolf

2007-12-01

This study sets out to demonstrate the normal developmental steps of the tegmen tympani and thus explains the typical localization of congenital tegmental defects. For this study, 79 macerated and formalin-fixed human temporal bones from 14th fetal week to adults were observed and prepared. Macroscopic and microscopic examination of the prenatal and postnatal changes of the tegmen tympani during its development. Temporal bones from 14th fetal week to adults underwent descriptive anatomic studies to understand the normal development of the tegmen tympani and to find a possible cause of its congenital defects. The medial part of the tegmen tympani develops from the otic capsule during chondral ossification, thus forming the tegmental process of the petrous part. The lateral part shows membranous ossification. The tegmental process cases a temporary bony dehiscence lateral to the geniculate ganglion between the 23rd and 25th fetal week. Congenital defects develop near the geniculate ganglion and seem to be due to an incomplete development of tegmental process of otic capsule. Because of that, congenital lesion of the tegmen tympani can be defined as an inner ear defect.

Image analysis for dental bone quality assessment using CBCT imaging

NASA Astrophysics Data System (ADS)

Suprijanto; Epsilawati, L.; Hajarini, M. S.; Juliastuti, E.; Susanti, H.

2016-03-01

Cone beam computerized tomography (CBCT) is one of X-ray imaging modalities that are applied in dentistry. Its modality can visualize the oral region in 3D and in a high resolution. CBCT jaw image has potential information for the assessment of bone quality that often used for pre-operative implant planning. We propose comparison method based on normalized histogram (NH) on the region of inter-dental septum and premolar teeth. Furthermore, the NH characteristic from normal and abnormal bone condition are compared and analyzed. Four test parameters are proposed, i.e. the difference between teeth and bone average intensity (s), the ratio between bone and teeth average intensity (n) of NH, the difference between teeth and bone peak value (Δp) of NH, and the ratio between teeth and bone of NH range (r). The results showed that n, s, and Δp have potential to be the classification parameters of dental calcium density.

Three-phase bone scan in osteomyelitis and other musculoskeletal disorders.

PubMed

Sutter, C W; Shelton, D K

1996-10-01

The three-phase bone scan is very sensitive and is the study of choice in the evaluation of patients with suspected osteomyelitis and normal radiographs. If the underlying bone pathology, such as a healing fracture or degenerative disease, is detected on radiographs of the bone, the indium-111-labeled autologous leukocyte scan is the most cost-effective second study. When fracture of the long bones is clinically suspected but radiographs are normal and a delay in definitive diagnosis is acceptable, it is practical and economical to take follow-up films in 10 to 14 days. In cases requiring prompt diagnosis or when follow-up radiographic films are not diagnostic, the three-phase bone scan is the most cost-effective study. The three-phase bone scan is also used in the evaluation of occupational and sports injuries, including shin splints, stress and occult fractures, enthesiopathies and reflex sympathetic dystrophy.

Second generation sequencing of microRNA in Human Bone Cells treated with Parathyroid Hormone or Dexamethasone.

PubMed

Laxman, Navya; Rubin, Carl-Johan; Mallmin, Hans; Nilsson, Olle; Tellgren-Roth, Christian; Kindmark, Andreas

2016-03-01

We investigated the impact of treatment with parathyroid hormone (PTH) and dexamethasone (DEX) for 2 and 24h by RNA sequencing of miRNAs in primary human bone (HOB) cells. A total of 207 million reads were obtained, and normalized absolute expression retrieved for 373 most abundant miRNAs. In naïve control cells, 7 miRNAs were differentially expressed (FDR<0.05) between the two time points. Ten miRNAs exhibited differential expression (FDR <0.05) across two time points and treatments after adjusting for expression in controls and were selected for downstream analyses. Results show significant effects on miRNA expression when comparing PTH with DEX at 2h with even more pronounced effects at 24h. Interestingly, several miRNAs exhibiting differences in expression are predicted to target genes involved in bone metabolism e.g. miR-30c2, miR-203 and miR-205 targeting RUNX2, and miR-320 targeting β-catenin (CTNNB1) mRNA expression. CTNNB1and RUNX2 levels were decreased after DEX treatment and increased after PTH treatment. Our analysis also identified 2 putative novel miRNAs in PTH and DEX treated cells at 24h. RNA sequencing showed that PTH and DEX treatment affect miRNA expression in HOB cells and that regulated miRNAs in turn are correlated with expression levels of key genes involved in bone metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

Mice with cancer-induced bone pain show a marked decline in day/night activity.

PubMed

Majuta, Lisa A; Guedon, Jean-Marc G; Mitchell, Stefanie A T; Kuskowski, Michael A; Mantyh, Patrick W

2017-09-01

Cancer-induced bone pain (CIBP) is the most common type of pain with cancer. In humans, this pain can be difficult to control and highly disabling. A major problem with CIBP in humans is that it increases on weight-bearing and/or movement of a tumor-bearing bone limiting the activity and functional status of the patient. Currently, there is less data concerning whether similar negative changes in activity occur in rodent models of CIBP. To determine whether there are marked changes in activity in a rodent model of CIBP and compare this to changes in skin hypersensitivity. Osteosarcoma cells were injected and confined to 1 femur of the adult male mouse. Every 7 days, spontaneous horizontal and vertical activities were assessed over a 20-hour day and night period using automated activity boxes. Mechanical hypersensitivity of the hind paw skin was assessed using von Frey testing. As the tumor cells grew within the femur, there was a significant decline in horizontal and vertical activity during the times of the day/night when the mice are normally most active. Mice also developed significant hypersensitivity in the skin of the hind paw in the tumor-bearing limb. Even when the tumor is confined to a single load-bearing bone, CIBP drives a significant loss of activity, which increases with disease progression. Understanding the mechanisms that drive this reduction in activity may allow the development of therapies that allow CIBP patients to better maintain their activity and functional status.

Neonatal High Bone Mass With First Mutation of the NF-κB Complex: Heterozygous De Novo Missense (p.Asp512Ser) RELA (Rela/p65).

PubMed

Frederiksen, Anja L; Larsen, Martin J; Brusgaard, Klaus; Novack, Deborah V; Knudsen, Peter Juel Thiis; Schrøder, Henrik Daa; Qiu, Weimin; Eckhardt, Christina; McAlister, William H; Kassem, Moustapha; Mumm, Steven; Frost, Morten; Whyte, Michael P

2016-01-01

Heritable disorders that feature high bone mass (HBM) are rare. The etiology is typically a mutation(s) within a gene that regulates the differentiation and function of osteoblasts (OBs) or osteoclasts (OCs). Nevertheless, the molecular basis is unknown for approximately one-fifth of such entities. NF-κB signaling is a key regulator of bone remodeling and acts by enhancing OC survival while impairing OB maturation and function. The NF-κB transcription complex comprises five subunits. In mice, deletion of the p50 and p52 subunits together causes osteopetrosis (OPT). In humans, however, mutations within the genes that encode the NF-κB complex, including the Rela/p65 subunit, have not been reported. We describe a neonate who died suddenly and unexpectedly and was found at postmortem to have HBM documented radiographically and by skeletal histopathology. Serum was not available for study. Radiographic changes resembled malignant OPT, but histopathological investigation showed morphologically normal OCs and evidence of intact bone resorption excluding OPT. Furthermore, mutation analysis was negative for eight genes associated with OPT or HBM. Instead, accelerated bone formation appeared to account for the HBM. Subsequently, trio-based whole exome sequencing revealed a heterozygous de novo missense mutation (c.1534_1535delinsAG, p.Asp512Ser) in exon 11 of RELA encoding Rela/p65. The mutation was then verified using bidirectional Sanger sequencing. Lipopolysaccharide stimulation of patient fibroblasts elicited impaired NF-κB responses compared with healthy control fibroblasts. Five unrelated patients with unexplained HBM did not show a RELA defect. Ours is apparently the first report of a mutation within the NF-κB complex in humans. The missense change is associated with neonatal osteosclerosis from in utero increased OB function rather than failed OC action. These findings demonstrate the importance of the Rela/p65 subunit within the NF-κB pathway for human skeletal homeostasis and represent a new genetic cause of HBM. © 2015 American Society for Bone and Mineral Research.

Growth, sexual and bone development in a boy with bilateral anorchia under testosterone treatment guided by the development of his monozygotic twin.

PubMed

Vandewalle, Sara; Van Caenegem, Eva; Craen, Margarita; Taes, Youri; Kaufman, Jean-Marc; T'Sjoen, Guy

2018-03-28

Sex steroids are essential for sexual maturation, linear growth and bone development. However, there is no consensus on the optimal timing, dosage and dosage interval of testosterone therapy to induce pubertal development and achieve a normal adult height and bone mass in children with hypogonadism. A monozygotic monochorial male twin pair, of which one boy was diagnosed with anorchia at birth due to testicular regression syndrome was followed from the age of 3 until the age of 18 years. Low dose testosterone substitution (testosterone esters 25 mg/2 weeks) was initiated in the affected twin based on the start of pubertal development in the healthy twin and then gradually increased accordingly. Both boys were followed until age 18 and were compared as regards to linear growth, sexual maturation, bone maturation and bone development. Before puberty induction both boys had a similar weight and height. During puberty, a slightly faster weight and height gain was observed in the affected twin. Both boys ended up however, with a similar and normal (near) adult height and weight and experienced a normal development of secondary sex characteristics. At the age of 17 and 18 years, bone mineral density, body composition and volumetric bone parameters at the forearm and calf were evaluated in both boys. The affected boy had a higher lean mass and muscle cross-sectional area. The bone mineral density at the lumbar spine and whole body was similar. Trabecular and cortical volumetric bone parameters were comparable. At one cortical site (proximal radius), however, the affected twin had a smaller periosteal and endosteal circumference with a thicker cortex. In conclusion, a low dose testosterone substitution in bilateral anorchia led to a normal onset of pubertal development and (near) adult height. Furthermore, there was no difference in bone mineral density at the age of 17 and 18 years.

PET/MRI of metabolic activity in osteoarthritis: A feasibility study.

PubMed

Kogan, Feliks; Fan, Audrey P; McWalter, Emily J; Oei, Edwin H G; Quon, Andrew; Gold, Garry E

2017-06-01

To evaluate positron emission tomography / magnetic resonance imaging (PET/MRI) knee imaging to detect and characterize osseous metabolic abnormalities and correlate PET radiotracer uptake with osseous abnormalities and cartilage degeneration observed on MRI. Both knees of 22 subjects with knee pain or injury were scanned at one timepoint, without gadolinium, on a hybrid 3.0T PET-MRI system following injection of 18 F-fluoride or 18 F-fluorodeoxyglucose (FDG). A musculoskeletal radiologist identified volumes of interest (VOIs) around bone abnormalities on MR images and scored bone marrow lesions (BMLs) and osteophytes using a MOAKS scoring system. Cartilage appearance adjacent to bone abnormalities was graded with MRI-modified Outerbridge classifications. On PET standardized uptake values (SUV) maps, VOIs with SUV greater than 5 times the SUV in normal-appearing bone were identified as high-uptake VOI (VOI High ). Differences in 18 F-fluoride uptake between bone abnormalities, BML, and osteophyte grades and adjacent cartilage grades on MRI were identified using Mann-Whitney U-tests. SUV max in all subchondral bone lesions (BML, osteophytes, sclerosis) was significantly higher than that of normal-appearing bone on MRI (P < 0.001 for all). Of the 172 high-uptake regions on 18 F-fluoride PET, 63 (37%) corresponded to normal-appearing subchondral bone on MRI. Furthermore, many small grade 1 osteophytes (40 of 82 [49%]), often described as the earliest signs of osteoarthritis (OA), did not show high uptake. Lastly, PET SUV max in subchondral bone adjacent to grade 0 cartilage was significantly lower compared to that of grades 1-2 (P < 0.05) and grades 3-4 cartilage (P < 0.001). PET/MRI can simultaneously assess multiple early metabolic and morphologic markers of knee OA across multiple tissues in the joint. Our findings suggest that PET/MR may detect metabolic abnormalities in subchondral bone, which appear normal on MRI. 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;45:1736-1745. © 2016 International Society for Magnetic Resonance in Medicine.

A compact DD neutron generator-based NAA system to quantify manganese (Mn) in bone in vivo.

PubMed

Liu, Yingzi; Byrne, Patrick; Wang, Haoyu; Koltick, David; Zheng, Wei; Nie, Linda H

2014-09-01

A deuterium-deuterium (DD) neutron generator-based neutron activation analysis (NAA) system has been developed to quantify metals, including manganese (Mn), in bone in vivo. A DD neutron generator with a flux of up to 3*10(9) neutrons s(-1) was set up in our lab for this purpose. Optimized settings, including moderator, reflector, and shielding material and thickness, were selected based on Monte Carlo (MC) simulations conducted in our previous work. Hand phantoms doped with different Mn concentrations were irradiated using the optimized DD neutron generator irradiation system. The Mn characteristic γ-rays were collected by an HPGe detector system with 100% relative efficiency. The calibration line of the Mn/calcium (Ca) count ratio versus bone Mn concentration was obtained (R(2) = 0.99) using the hand phantoms. The detection limit (DL) was calculated to be about 1.05 μg g(-1) dry bone (ppm) with an equivalent dose of 85.4 mSv to the hand. The DL can be reduced to 0.74 ppm by using two 100% HPGe detectors. The whole body effective dose delivered to the irradiated subject was calculated to be about 17 μSv. Given the average normal bone Mn concentration of 1 ppm in the general population, this system is promising for in vivo bone Mn quantification in humans.

Stem cells and bone diseases: new tools, new perspective.

PubMed

Riminucci, Mara; Remoli, Cristina; Robey, Pamela G; Bianco, Paolo

2015-01-01

Postnatal skeletal stem cells are a unique class of progenitors with biological properties that extend well beyond the limits of stemness as commonly defined. Skeletal stem cells sustain skeletal tissue homeostasis, organize and maintain the complex architectural structure of the bone marrow microenvironment and provide a niche for hematopoietic progenitor cells. The identification of stem cells in the human post-natal skeleton has profoundly changed our approach to the physiology and pathology of this system. Skeletal diseases have been long interpreted essentially in terms of defective function of differentiated cells and/or abnormal turnover of the matrix that they produce. The notion of a skeletal stem cell has brought forth multiple, novel concepts in skeletal biology that provide potential alternative concepts. At the same time, the recognition of the complex functions played by skeletal progenitors, such as the structural and functional organization of the bone marrow, has provided an innovative, unifying perspective for understanding bone and bone marrow changes simultaneously occurring in many disorders. Finally, the possibility to isolate and highly enrich for skeletal progenitors, enables us to reproduce perfectly normal or pathological organ miniatures. These, in turn, provide suitable models to investigate and manipulate the pathogenetic mechanisms of many genetic and non-genetic skeletal diseases. This article is part of a Special Issue entitled Stem cells and Bone. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Increased Intake of Selected Vegetables, Herbs and Fruit may Reduce Bone Turnover in Post-Menopausal Women

PubMed Central

Gunn, Caroline Ann; Weber, Janet Louise; McGill, Anne-Thea; Kruger, Marlena Cathorina

2015-01-01

Increased consumption of vegetables/herbs/fruit may reduce bone turnover and urinary calcium loss in post-menopausal women because of increased intake of polyphenols and potassium, but comparative human studies are lacking. The main aim was to compare bone turnover markers and urinary calcium excretion in two randomised groups (n = 50) of healthy post-menopausal women consuming ≥9 servings of different vegetables/herbs/fruit combinations (three months). Group A emphasised a generic range of vegetables/herbs/fruit, whereas Group B emphasised specific vegetables/herbs/fruit with bone resorption-inhibiting properties (Scarborough Fair Diet), with both diets controlled for potential renal acid load (PRAL). Group C consumed their usual diet. Plasma bone markers, urinary electrolytes (24 h) and estimated dietary PRAL were assessed at baseline and 12 weeks. Procollagen type I N propeptide (PINP) decreased (−3.2 μg/L, p < 0.01) in the B group only, as did C-terminal telopeptide of type I collagen (CTX) (−0.065 μg/L, p < 0.01) in women with osteopenia compared to those with normal bone mineral density (BMD) within this group. Intervention Groups A and B had decreased PRAL, increased urine pH and significantly decreased urinary calcium loss. Urinary potassium increased in all groups, reflecting a dietary change. In conclusion, Group B demonstrated positive changes in both turnover markers and calcium conservation. PMID:25856221

Deterioration of Cortical Bone Microarchitecture: Critical Component of Renal Osteodystrophy Evaluation.

PubMed

Sharma, Ashish K; Toussaint, Nigel D; Masterson, Rosemary; Holt, Stephen G; Rajapakse, Chamith S; Ebeling, Peter R; Mohanty, Sindhu T; Baldock, Paul; Elder, Grahame J

2018-05-23

Cortical bone is a significant determinant of bone strength and its deterioration contributes to bone fragility. Thin cortices and increased cortical porosity have been noted in patients with chronic kidney disease (CKD), but the "Turnover Mineralization Volume" classification of renal osteodystrophy does not emphasize cortical bone as a key parameter. We aimed to assess trabecular and cortical bone microarchitecture by histomorphometry and micro-CT in patients with CKD G5 and 5D (dialysis). Transiliac bone biopsies were performed in 14 patients undergoing kidney transplantation (n = 12) and parathyroidectomy (n = 2). Structural parameters were analysed by histomorphometry and micro-CT including trabecular bone volume, thickness (TbTh), number (TbN) and separation and cortical thickness (CtTh) and porosity (CtPo). Indices of bone remodelling and mineralisation were obtained and relationships to bone biomarkers examined. Associations were determined by Spearman's or Pearson's rank correlation coefficients. By micro-CT, trabecular parameters were within normal ranges in most patients, but all patients showed very low CtTh (127 ± 44 µm) and high CtPo (60.3 ± 22.5%). CtPo was inversely related to TbN (r = -0.56; p = 0.03) by micro-CT and to TbTh (r = -0.60; p = 0.024) by histomorphometry and correlated to parathyroid hormone values (r = 0.62; p = 0.021). By histomorphometry, bone turnover was high in 50%, low in 21% and normal in 29%, while 36% showed abnormal patterns of mineralization. Significant positive associations were observed between osteoblast surface, osteoclast surface, mineralization surface and bone turnover markers. Deterioration of cortical -microarchitecture despite predominantly normal trabecular parameters reinforces the importance of comprehensive cortical evaluation in patients with CKD. © 2018 S. Karger AG, Basel.

Increases in bone density during treatment of men with idiopathic hypogonadotropic hypogonadism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finkelstein, J.S.; Klibanski, A.; Neer, R.M.

To assess the effects of gonadal steroid replacement on bone density in men with osteoporosis due to severe hypogonadism, we measured cortical bone density in the distal radius by 125I photon absorptiometry and trabecular bone density in the lumbar spine by quantitative computed tomography in 21 men with isolated GnRH deficiency while serum testosterone levels were maintained in the normal adult male range for 12-31 months (mean +/- SE, 23.7 +/- 1.1). In men who initially had fused epiphyses (n = 15), cortical bone density increased from 0.71 +/- 0.02 to 0.74 +/- 0.01 g/cm2 (P less than 0.01), whilemore » trabecular bone density did not change (116 +/- 9 compared with 119 +/- 7 mg/cm3). In men who initially had open epiphyses (n = 6), cortical bone density increased from 0.62 +/- 0.01 to 0.70 +/- 0.03 g/cm2 (P less than 0.01), while trabecular bone density increased from 96 +/- 13 to 109 +/- 12 mg/cm3 (P less than 0.01). Cortical bone density increased 0.03 +/- 0.01 g/cm2 in men with fused epiphyses and 0.08 +/- 0.02 g/cm2 in men with open epiphyses (P less than 0.05). Despite these increases, neither cortical nor trabecular bone density returned to normal levels. Histomorphometric analyses of iliac crest bone biopsies demonstrated that most of the men had low turnover osteoporosis, although some men had normal to high turnover osteoporosis. We conclude that bone density increases during gonadal steroid replacement of GnRH-deficient men, particularly in men who are skeletally immature.« less

Atomic scale chemical tomography of human bone

NASA Astrophysics Data System (ADS)

Langelier, Brian; Wang, Xiaoyue; Grandfield, Kathryn

2017-01-01

Human bone is a complex hierarchical material. Understanding bone structure and its corresponding composition at the nanometer scale is critical for elucidating mechanisms of biomineralization under healthy and pathological states. However, the three-dimensional structure and chemical nature of bone remains largely unexplored at the nanometer scale due to the challenges associated with characterizing both the structural and chemical integrity of bone simultaneously. Here, we use correlative transmission electron microscopy and atom probe tomography for the first time, to our knowledge, to reveal structures in human bone at the atomic level. This approach provides an overlaying chemical map of the organic and inorganic constituents of bone on its structure. This first use of atom probe tomography on human bone reveals local gradients, trace element detection of Mg, and the co-localization of Na with the inorganic-organic interface of bone mineral and collagen fibrils, suggesting the important role of Na-rich organics in the structural connection between mineral and collagen. Our findings provide the first insights into the hierarchical organization and chemical heterogeneity in human bone in three-dimensions at its smallest length scale - the atomic level. We demonstrate that atom probe tomography shows potential for new insights in biomineralization research on bone.

Alterations in TNF- and IL-related gene expression in space-flown WI38 human fibroblasts

NASA Technical Reports Server (NTRS)

Semov, Alexandre; Semova, Nathalia; Lacelle, Chantale; Marcotte, Richard; Petroulakis, Emmanuel; Proestou, Gregory; Wang, Eugenia

2002-01-01

Spaceflight, just like aging, causes profound changes in musculoskeletal parameters, which result in decreased bone density and muscular weakness. As these conditions decrease our ability to conduct long-term manned space missions, and increase bone frailty in the elderly, the identification of genes responsible for the apparition of these physiological changes will be of great benefit. Thus, we developed and implemented a new microarray approach to investigate the changes in normal WI38 human fibroblast gene expression that arise as a consequence of space flight. Using our microarray, we identified changes in the level of expression of 10 genes, belonging to either the tumor necrosis factor- (TNF) or interleukin- (IL) related gene families in fibroblasts when WI38 cells exposed to microgravity during the STS-93 Space Shuttle mission were compared with ground controls. The genes included two ligands from the TNF superfamily, TWEAK and TNFSF15; two TNF receptor-associated proteins, NSMAF and PTPN13; three TNF-inducible genes, ABC50, PTX3, and SCYA13; TNF-alpha converting enzyme, IL-1 receptor antagonist, and IL-15 receptor alpha chain. Most of these are involved in either the regulation of bone density, and as such the development of spaceflight osteopenia, or in the development of proinflammatory status.

Effect of puberty on body composition.

PubMed

Loomba-Albrecht, Lindsey A; Styne, Dennis M

2009-02-01

Here we examine the effect of puberty on components of human body composition, including adiposity (total body fat, percentage body fat and fat distribution), lean body mass and bone mineral content and density. New methods and longitudinal studies have expended our knowledge of these remarkable changes. Human differences in adiposity, fat free mass and bone mass reflect differences in endocrine status (particularly with respect to estrogens, androgens, growth hormone and IGF-1), genetic factors, ethnicity and the environment. During puberty, males gain greater amounts of fat free mass and skeletal mass, whereas females acquire significantly more fat mass. Both genders reach peak bone accretion during the pubertal years, though males develop a greater skeletal mass. Body proportions and fat distribution change during the pubertal years as well, with males assuming a more android body shape and females assuming a more gynecoid shape. Pubertal body composition may predict adult body composition and affects both pubertal timing and future health. Sexual dimorphism exists to a small degree at birth, but striking differences develop during the pubertal years. The development of this dimorphism in body composition is largely regulated by endocrine factors, with critical roles played by growth hormone and gonadal steroids. It is important for clinicians and researchers to know the normal changes in order to address pathologic findings in disease states.

Effects of human recombinant erythropoietin on differentiation and distribution of erythroid progenitor cells on murine medullary and splenic erythropoiesis during hypoxia and post-hypoxia.

PubMed

Mide, S M; Huygens, P; Bozzini, C E; Fernandez Pol, J A

2001-01-01

Hemopoietic cells, the extracellular matrix, growth factors and the microenvironment are involved in the regulation of hemopoiesis. Although the regulation of erythropoiesis is well understood at the cellular level in vivo and in vitro, the role of hemopoietic sites of erythroid progenitors production has not been well defined in both steady state conditions and in stress erythropoiesis. In this study we examined the qualitative erythroid differentiation and quantitative changes of the erythroid progenitors in different erythropoietic organs during erythropoiesis of stress in a hypoxia-induced polycythemia and post-hypoxic changes in a mice model. Chronic intermittent exposure to hypobaric hypoxia induced polycythemia in mice and the post-hypoxic period was characterized by total suppression of erythropoiesis. The number and distribution in hemopoietic sites of Immature Erythroid Burst (BFU-EI), Mature Erythroid Burst (BFU-EM) and Erythroid Colony Forming Units (CFU-E) was evaluated in bone marrow and spleen of hypoxic and post-hypoxic mice after removal from the chamber. The number of BFU-EI and CFU-E, was evaluated in both femoral bone marrow and spleen of ex-hypoxic polycythemic mice, at two times intervals after the end of hypoxia. We found that in both bone marrow and spleen, the kinetics of the CFU-E pool was characterized by a sharp fall from above normal to lower than normal levels. BFU-EM increased from normal to higher than normal levels. These results have been correlated with both erythropoietin (EPO) and the erythropoietic activity. The results show that EPO levels largely control both the differentiation and the amplification of the CFU-E pool and they suggest that EPO may acts as a "survival factor" at the CFU-E level and/or increase the flow of cells from BFU-E to CFU-E. After the termination of the period of hypoxia and during post-hypoxia there was a reduction in EPO production which subsequently caused a depletion of the CFU-E population, indicating that the size of the CFU-E pool is EPO-dependent. After the injection of 1U of recombinant human erythropoietin (rHuEPO) the size of that pool was increased and the pool of BFU-EI was decreased. It is noteworthy that our studies show that the spleen functions as a large reservoir of erythroid precursors for hypoxia-induced stress erythropoiesis.

[Regional blood flow and bone uptake of methylene-diphosphonate-technetium-99m].

PubMed

Vattimo, A; Martini, G; Pisani, M

1983-05-30

Sudeck's atrophy of the foot is an acute, patchy osteoporosis that, on bone scan, shows an increase in both bone blood flow and local bone uptake of bone-seeking radionuclides. The purpose of this study was to evaluate the relationship between bone uptake of 99mTc-MDP and local bone blood flow. In some patients with Sudeck's atrophy of one foot we measured local bone blood flow and bone uptake of 99mTc-MDP. External counting of radioactivity, with a count-rate of 1 second was performed for 60 minutes after i.v. injection of a known dose of 99mTc-MDP in some patients with Sudeck's atrophy of the foot. The regions of interest (ROI) were selected on the basis of a bone scan performed 24 hours earlier. We assumed that the data recorded during the first seconds (7-10) reflect local blood flow and the data at 60 minutes reflect the bone uptake. The ratio between the local blood flow in the involved and healthy foot was higher than the local bone uptake ratio. The ratio between bone uptake and local bone blood flow was higher in the normal foot than in the affected one. These results suggest that the bone avidity for bone-seeking radionuclides is lower in Sudeck's atrophy than in normal bone.

Effects of microgravity on bone and calcium homeostasis

NASA Astrophysics Data System (ADS)

Zérath, E.

Mechanical function is known to be of crucial importance for the maintenance of bone tissue. Gravity on one hand and muscular effort on the other hand are required for normal skeletal structure. It has been shown by numerous experimental studies that loss of total-body calcium, and marked skeletal changes occur in people who have flown in space. However, most of the pertinent investigations have been conducted on animal models, including rats and non-human primates, and a reasonably clear picture of bone response to spaceflight has emerged during the past few years. Osteopenia induced by microgravity was found to be associated with reduction in both cortical and trabecular bone formation, alteration in mineralization patterns, and disorganization of collagen, and non-collagenous protein metabolism. Recently, cell-culture techniques have offered a direct approach of altered gravity effects at the osteoblastic-cell level. But the fundamental mechanisms by which bone and calcium are lost during spaceflight are not yet fully known. Infrequenccy and high financial cost of flights have created the necessity to develop on-Earth models designed to mimic weightlessness effects. Antiorthostatic suspension devices are now commonly used to obtain hindlimb unloading in rats, with skeletal effects similar to those observed after spaceflight. Therefore, actual and ``simulated'' spaceflights, with investigations conducted at whole body and cellular levels, are needed to elucidate pathogeny of bone loss in space, to develop effective countermeasures, and to study recovery processes of bone changes after return to Earth.

Long-Bone Injury Criteria for Use with the Articulated Total Body Model

DTIC Science & Technology

1981-01-01

bone - human, canine, bovine, etc.; condition of bone - dry, wet , embalmed , fresh; subject variations - height, weight, health, sex, age, etc; whole bone...stress strain curves ob- tained by McElhaney for various strain rates in compression. This is for embalmed human compact bone. Ultimate stress, ultimate...reported for fresh human bone of 25,000 psi (see Table 1). Recall that the McElhaney data is from embalmed subjects. If it is assumed, for lack of any real

78 FR 50104 - Notice of Inventory Completion: U.S. Department of the Interior, National Park Service, San Juan...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... individuals were identified. The 60 associated funerary objects are 1 splinter awl made from deer bone, 1 tip... flakes, 47 non-human skeletal fragments and non-human teeth, and 2 bags of non-human bone. In the Federal... identified. The 34 associated funerary objects are 28 non-human bone fragments, 1 miniature bone club, and 5...

Stem cells and bone diseases: new tools, new perspective

PubMed Central

Riminucci, Mara; Remoli, Cristina; Robey, Pamela G.; Bianco, Paolo

2017-01-01

Postnatal skeletal stem cells are a unique class of progenitors with biological properties that extend well beyond the limits of stemness as commonly defined. Skeletal stem cells sustain skeletal tissue homeostasis, organize and maintain the complex architectural structure of the bone marrow microenvironment and provide a niche for hematopoietic progenitor cells. The identification of stem cells in the human post-natal skeleton has profoundly changed our approach to the physiology and pathology of this system. Skeletal diseases have been long interpreted essentially in terms of defective function of differentiated cells and/or abnormal turnover of the matrix they produce. The notion of a skeletal stem cell has brought forth multiple, novel concepts in skeletal biology that provide potential alternative concepts. At the same time, the recognition of the complex functions played by skeletal progenitors, such as the structural and functional organization of the bone marrow, has provided an innovative, unifying perspective for understanding bone and bone marrow changes simultaneously occurring in many disorders. Finally, the possibility to isolate and highly enrich for skeletal progenitors, enables us to reproduce perfectly normal or pathological organ miniatures. These, in turn, provide suitable models to investigate and manipulate the pathogenetic mechanisms of many genetic and non-genetic skeletal diseases. PMID:25240458

Partially degradable friction-welded pure iron-stainless steel 316L bone pin.

PubMed

Nasution, A K; Murni, N S; Sing, N B; Idris, M H; Hermawan, H

2015-01-01

This article describes the development of a partially degradable metal bone pin, proposed to minimize the occurrence of bone refracture by avoiding the creation of holes in the bone after pin removal procedure. The pin was made by friction welding and composed of two parts: the degradable part that remains in the bone and the nondegradable part that will be removed as usual. Rods of stainless steel 316L (nondegradable) and pure iron (degradable) were friction welded at the optimum parameters: forging pressure = 33.2 kPa, friction time = 25 s, burn-off length = 15 mm, and heat input = 4.58 J/s. The optimum tensile strength and elongation was registered at 666 MPa and 13%, respectively. A spiral defect formation was identified as the cause for the ductile fracture of the weld joint. A 40-µm wide intermetallic zone was identified along the fusion line having a distinct composition of Cr, Ni, and Mo. The corrosion rate of the pin gradually decreased from the undeformed zone of pure iron to the undeformed zone of stainless steel 316L. All metallurgical zones of the pin showed no toxic effect toward normal human osteoblast cells, confirming the ppb level of released Cr and Ni detected in the cell media were tolerable. © 2014 Wiley Periodicals, Inc.

Microgravity

NASA Image and Video Library

1998-01-01

The heart of the bioreactor is the rotating wall vessel, shown without its support equipment. Volume is about 125 mL. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

NASA Bioreactor

NASA Technical Reports Server (NTRS)

1998-01-01

The heart of the bioreactor is the rotating wall vessel, shown without its support equipment. Volume is about 125 mL. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

Leukemic blast cell colony formation in semisolid culture with erythropoietin: a case report of acute poorly differentiated erythroid leukemia.

PubMed

Tomonaga, M; Jinnai, I; Tagawa, M; Amenomori, T; Nishino, K; Yao, E; Nonaka, H; Kuriyama, K; Yoshida, Y; Matsuo, T

1987-02-01

The bone marrow of a patient with acute undifferentiated leukemia developed unique colonies after a 14-day culture in erythropoietin (EPO)-containing methylcellulose. The colonies consisted of 20 to 200 nonhemoglobinized large blast cells. Cytogenetic analysis of single colonies revealed hypotetraploid karyotypes with several marker chromosomes that were identical to those found in directly sampled bone marrow. The concurrently formed erythroid bursts showed only normal karyotypes. No leukemic colony formation was observed in other culture systems with either colony-stimulating activity (CSA) or phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM). The leukemic colonies exhibited a complete EPO-dose dependency similar to that of the patient's normal BFU-E. Although cytochemical and immunologic marker studies of the bone marrow cells failed to clarify the cell lineage of the leukemic cells with extraordinarily large cell size, ultrastructural study revealed erythroid differentiation such as siderosome formation in the cytoplasm and ferritin particles in the rhophecytosis invaginations. These findings indicate that the patient had poorly differentiated erythroid leukemia and that some of the clonogenic cells might respond to EPO in vitro. Corresponding to this biological feature, the leukemic cells were markedly decreased in number in response to repeated RBC transfusions, and partial remission was obtained. These observations suggest that erythroid leukemia distinct from erythroleukemia (M6) with a myeloblastic component, can develop as a minor entity of human acute leukemia.

Unbiased estimation of the calcaneus volume using the Cavalieri principle on computed tomography images.

PubMed

Acer, N; Bayar, B; Basaloglu, H; Oner, E; Bayar, K; Sankur, S

2008-11-20

The size and shape of tarsal bones are especially relevant when considering some orthopedic diseases such as clubfoot. For this reason, the measurements of the tarsal bones have been the subject of many studies, none of which has used stereological methods to estimate the volume. In the present stereological study, we estimated the volume of calcaneal bone of normal feet and dry bones. We used a combination of the Cavalieri principle and computer tomographic scans taken from eight males and nine dry calcanei to estimate the volumes of calcaneal bones. The mean volume of dry calcaneal bones was estimated, producing mean results using the point-counting method and Archimedes principle being 49.11+/-10.7 or 48.22+/-11.92 cm(3), respectively. A positive correlation was found between anthropometric measurements and the volume of calcaneal bones. The findings of the present study using the stereological methods could provide data for the evaluation of normal and pathological volumes of calcaneal bones.

Transient chondrogenic phase in the intramembranous pathway during normal skeletal development.

PubMed

Nah, H D; Pacifici, M; Gerstenfeld, L C; Adams, S L; Kirsch, T

2000-03-01

Calvarial and facial bones form by intramembranous ossification, in which bone cells arise directly from mesenchyme without an intermediate cartilage anlage. However, a number of studies have reported the emergence of chondrocytes from in vitro calvarial cell or organ cultures and the expression of type II collagen, a cartilage-characteristic marker, in developing calvarial bones. Based on these findings we hypothesized that a covert chondrogenic phase may be an integral part of the normal intramembranous pathway. To test this hypothesis, we analyzed the temporal and spatial expression patterns of cartilage characteristic genes in normal membranous bones from chick embryos at various developmental stages (days 12, 15 and 19). Northern and RNAse protection analyses revealed that embryonic frontal bones expressed not only the type I collagen gene but also a subset of cartilage characteristic genes, types IIA and XI collagen and aggrecan, thus resembling a phenotype of prechondrogenic-condensing mesenchyme. The expression of cartilage-characteristic genes decreased with the progression of bone maturation. Immunohistochemical analyses of developing embryonic chick heads indicated that type II collagen and aggrecan were produced by alkaline phosphatase activity positive cells engaged in early stages of osteogenic differentiation, such as cells in preosteogenic-condensing mesenchyme, the cambium layer of periosteum, the advancing osteogenic front, and osteoid bone. Type IIB and X collagen messenger RNAs (mRNA), markers for mature chondrocytes, were also detected at low levels in calvarial bone but not until late embryonic stages (day 19), indicating that some calvarial cells may undergo overt chondrogenesis. On the basis of our findings, we propose that the normal intramembranous pathway in chicks includes a previously unrecognized transient chondrogenic phase similar to prechondrogenic mesenchyme, and that the cells in this phase retain chondrogenic potential that can be expressed in specific in vitro and in vivo microenvironments.

The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering

NASA Astrophysics Data System (ADS)

Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A.; Janeczek, Agnieszka A.; Kontouli, Nasia; Kanczler, Janos M.; Evans, Nicholas D.; Oreffo, Richard Oc

2016-08-01

Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering.

Validating in vivo Raman spectroscopy of bone in human subjects

NASA Astrophysics Data System (ADS)

Esmonde-White, Francis W. L.; Morris, Michael D.

2013-03-01

Raman spectroscopy can non-destructively measure properties of bone related to mineral density, mineral composition, and collagen composition. Bone properties can be measured through the skin in animal and human subjects, but correlations between the transcutaneous and exposed bone measurements have only been reported for human cadavers. In this study, we examine human subjects to collect measurements transcutaneously, on surgically exposed bone, and on recovered bone fragments. This data will be used to demonstrate in vivo feasibility and to compare transcutaneous and exposed Raman spectroscopy of bone. A commercially available Raman spectrograph and optical probe operating at 785 nm excitation are used for the in vivo measurements. Requirements for applying Raman spectroscopy during a surgery are also discussed.

Beneficial Effects of Autologous Bone Marrow-Derived Mesenchymal Stem Cells in Naturally Occurring Tendinopathy

PubMed Central

Smith, Roger Kenneth Whealands; Werling, Natalie Jayne; Dakin, Stephanie Georgina; Alam, Rafiqul; Goodship, Allen E.; Dudhia, Jayesh

2013-01-01

Tendon injuries are a common age-related degenerative condition where current treatment strategies fail to restore functionality and normal quality of life. This disease also occurs naturally in horses, with many similarities to human tendinopathy making it an ideal large animal model for human disease. Regenerative approaches are increasingly used to improve outcome involving mesenchymal stem cells (MSCs), supported by clinical data where injection of autologous bone marrow derived MSCs (BM-MSCs) suspended in marrow supernatant into injured tendons has halved the re-injury rate in racehorses. We hypothesized that stem cell therapy induces a matrix more closely resembling normal tendon than the fibrous scar tissue formed by natural repair. Twelve horses with career-ending naturally-occurring superficial digital flexor tendon injury were allocated randomly to treatment and control groups. 1X107 autologous BM-MSCs suspended in 2 ml of marrow supernatant were implanted into the damaged tendon of the treated group. The control group received the same volume of saline. Following a 6 month exercise programme horses were euthanized and tendons assessed for structural stiffness by non-destructive mechanical testing and for morphological and molecular composition. BM-MSC treated tendons exhibited statistically significant improvements in key parameters compared to saline-injected control tendons towards that of normal tendons and those in the contralateral limbs. Specifically, treated tendons had lower structural stiffness (p<0.05) although no significant difference in calculated modulus of elasticity, lower (improved) histological scoring of organisation (p<0.003) and crimp pattern (p<0.05), lower cellularity (p<0.007), DNA content (p<0.05), vascularity (p<0.03), water content (p<0.05), GAG content (p<0.05), and MMP-13 activity (p<0.02). Treatment with autologous MSCs in marrow supernatant therefore provides significant benefits compared to untreated tendon repair in enhancing normalisation of biomechanical, morphological, and compositional parameters. These data in natural disease, with no adverse findings, support the use of this treatment for human tendon injuries. PMID:24086616

Influence of Body Weight on Bone Mass, Architecture, and Turnover

PubMed Central

Iwaniec, Urszula T.; Turner, Russell T.

2016-01-01

Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. While the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size. PMID:27352896

THE EFFECT OF STRAIN RATE ON FRACTURE TOUGHNESS OF HUMAN CORTICAL BONE: A FINITE ELEMENT STUDY

PubMed Central

Ural, Ani; Zioupos, Peter; Buchanan, Drew; Vashishth, Deepak

2011-01-01

Evaluating the mechanical response of bone under high loading rates is crucial to understanding fractures in traumatic accidents or falls. In the current study, a computational approach based on cohesive finite element modeling was employed to evaluate the effect of strain rate on fracture toughness of human cortical bone. Two-dimensional compact tension specimen models were simulated to evaluate the change in initiation and propagation fracture toughness with increasing strain rate (range: 0.08 to 18 s−1). In addition, the effect of porosity in combination with strain rate was assessed using three-dimensional models of microcomputed tomography-based compact tension specimens. The simulation results showed that bone’s resistance against the propagation of fracture decreased sharply with increase in strain rates up to 1 s−1 and attained an almost constant value for strain rates larger than 1 s−1. On the other hand, initiation fracture toughness exhibited a more gradual decrease throughout the strain rates. There was a significant positive correlation between the experimentally measured number of microcracks and the fracture toughness found in the simulations. Furthermore, the simulation results showed that the amount of porosity did not affect the way initiation fracture toughness decreased with increasing strain rates, whereas it exacerbated the same strain rate effect when propagation fracture toughness was considered. These results suggest that strain rates associated with falls lead to a dramatic reduction in bone’s resistance against crack propagation. The compromised fracture resistance of bone at loads exceeding normal activities indicates a sharp reduction and/or absence of toughening mechanisms in bone during high strain conditions associated with traumatic fracture. PMID:21783112

Geometric and mechanical evaluation of 3D-printing materials for skull base anatomical education and endoscopic surgery simulation - A first step to create reliable customized simulators.

PubMed

Favier, Valentin; Zemiti, Nabil; Caravaca Mora, Oscar; Subsol, Gérard; Captier, Guillaume; Lebrun, Renaud; Crampette, Louis; Mondain, Michel; Gilles, Benjamin

2017-01-01

Endoscopic skull base surgery allows minimal invasive therapy through the nostrils to treat infectious or tumorous diseases. Surgical and anatomical education in this field is limited by the lack of validated training models in terms of geometric and mechanical accuracy. We choose to evaluate several consumer-grade materials to create a patient-specific 3D-printed skull base model for anatomical learning and surgical training. Four 3D-printed consumer-grade materials were compared to human cadaver bone: calcium sulfate hemihydrate (named Multicolor), polyamide, resin and polycarbonate. We compared the geometric accuracy, forces required to break thin walls of materials and forces required during drilling. All materials had an acceptable global geometric accuracy (from 0.083mm to 0.203mm of global error). Local accuracy was better in polycarbonate (0.09mm) and polyamide (0.15mm) than in Multicolor (0.90mm) and resin (0.86mm). Resin and polyamide thin walls were not broken at 200N. Forces needed to break Multicolor thin walls were 1.6-3.5 times higher than in bone. For polycarbonate, forces applied were 1.6-2.5 times higher. Polycarbonate had a mode of fracture similar to the cadaver bone. Forces applied on materials during drilling followed a normal distribution except for the polyamide which was melted. Energy spent during drilling was respectively 1.6 and 2.6 times higher on bone than on PC and Multicolor. Polycarbonate is a good substitute of human cadaver bone for skull base surgery simulation. Thanks to short lead times and reasonable production costs, patient-specific 3D printed models can be used in clinical practice for pre-operative training, improving patient safety.

Human bone marrow harbors cells with neural crest-associated characteristics like human adipose and dermis tissues

PubMed Central

Coste, Cécile; Neirinckx, Virginie; Sharma, Anil; Agirman, Gulistan; Rogister, Bernard; Foguenne, Jacques; Lallemend, François

2017-01-01

Adult neural crest stem-derived cells (NCSC) are of extraordinary high plasticity and promising candidates for use in regenerative medicine. Several locations such as skin, adipose tissue, dental pulp or bone marrow have been described in rodent, as sources of NCSC. However, very little information is available concerning their correspondence in human tissues, and more precisely for human bone marrow. The main objective of this study was therefore to characterize NCSC from adult human bone marrow. In this purpose, we compared human bone marrow stromal cells to human adipose tissue and dermis, already described for containing NCSC. We performed comparative analyses in terms of gene and protein expression as well as functional characterizations. It appeared that human bone marrow, similarly to adipose tissue and dermis, contains NESTIN+ / SOX9+ / TWIST+ / SLUG+ / P75NTR+ / BRN3A+/ MSI1+/ SNAIL1+ cells and were able to differentiate into melanocytes, Schwann cells and neurons. Moreover, when injected into chicken embryos, all those cells were able to migrate and follow endogenous neural crest migration pathways. Altogether, the phenotypic characterization and migration abilities strongly suggest the presence of neural crest-derived cells in human adult bone marrow. PMID:28683107

Electron Micrographs of Quail Limb Bones formed in microgravity

NASA Technical Reports Server (NTRS)

2003-01-01

Electron micrographs of quail limb bones that formed under the influence of microgravity show decreased mineralization compared to bones formed in normal gravity. The letters B and C indicate bone and cartilage sides of the sample, respectively, with the arrows marking the junction between bone and cartilage cells. The asterisks indicate where mineralization begins. The bone that developed during spaceflight (top) shows less mineral compared to the control sample (bottom); the control sample clearly shows mineral deposits (dark spots) that are absent in the flight sample. Quail eggs are small and develop quickly, making them ideal for space experiments. In late 2001, the Avian Development Facility (ADF) made its first flight and carried eggs used in two investigations, development and function of the irner-ear balance system in normal and altered gravity environments, and skeletal development in embryonic quail.

Biomechanical testing of isolated bones: holographic study

NASA Astrophysics Data System (ADS)

Silvennoinen, Raimo; Nygren, Kaarlo; Karna, Markku

1992-08-01

Holographic nondestructive testing (HNDT) is used to investigate the complex structures of bones of various shapes and sizes subjected to forces. Three antlered deer skulls of different species were investigated and significant species-specific differences were observed. The HNDT method was also used to verify the advanced healing of an osteosynthetized sheep jawbone. Radioulnar bones of a normal and an orphaned moose calf were subjected to a bending test. The undernourished calf showed torsio displacement combined with the bending of the bone, which was not seen in the normal calf. The effects of the masticatory forces on the moose skull surface were studied by simulating masseter muscle contractions with jawbones in occlusion. The fringe patterns showed fast-moving bone surfaces on the naso- maxillo-lacrimal region.

High-intensity exercise of short duration alters bovine bone density and shape.

PubMed

Hiney, K M; Nielsen, B D; Rosenstein, D; Orth, M W; Marks, B P

2004-06-01

The ability of short-duration high-intensity exercise to stimulate bone formation in confinement was investigated using immature Holstein bull calves as a model. Eighteen bull calves, 8 wk of age, were assigned to one of three treatment groups: 1) group-housed (GR, which served as a control), 2) confined with no exercise (CF), or 3) confined with exercise (EX). The exercise protocol consisted of running 50 m on a concrete surface once daily, 5 d/wk. Confined calves remained stalled for the 42-d duration of the trial. Blood samples were taken to analyze concentrations of osteocalcin and deoxypyridinoline, markers of bone formation and resorption. At the completion of the trial, calves were humanely killed, and both forelegs were collected. The fused third and fourth metacarpal bone was scanned using computed tomography for determination of cross-sectional geometry and bone mineral density. Three-point bending tests to failure were performed on metacarpal bones. The exercise protocol resulted in the formation of a rounder bone in EX as well as in increased dorsal cortex thickness compared with those in the GR and CF. The exercised calves had a significantly smaller medullary cavity than CF and GR (P < 0.01) and a larger percentage of cortical bone area than CF (P < 0.01). Dorsal, palmar, and total bone mineral density was greater in EX than in CF (P < 0.05), and palmar and total bone mineral densities were greater (P < 0.05) in EX than in GR. There was a trend for the bones of EX to have a higher fracture force than CF (P < 0.10). Osteocalcin concentrations normalized from d 0 were higher in EX than CF (P < 0.05). Therefore, the exercise protocol altered bone shape and seemed to increase bone formation comparison with the stalled and group-housed calves.

The Use of Backscattered Electron Imaging and Transmission Electron Microscopy to Assess Bone Architecture and Mineral Loci: Effect of Intermittent Slow-Release Sodium Fluoride Therapy

NASA Astrophysics Data System (ADS)

Zerwekh, Joseph E.; Bellotto, Dennis; Prostak, Kenneth S.; Hagler, Herbert K.; Pak, Charles Y. C.

1996-04-01

Backscattered electron imaging (BEI) and transmission electron microscopy (TEM) were used to examine the effects of treatment with intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate on bone architecture and crystallinity. Examination was performed in nondecalcified biopsies obtained from patients following up to four years of therapy (placebo or SRNaF) and compared to pretreatment biopsies from each patient, as well as to bone from young, normal subjects. BEI images disclosed increased areas of recent bone formation following fluoride administration. There was no evidence of a mineralization defect in any biopsy and both cortical and trabecular architecture remained normal. TEM analysis demonstrated intrafibrillar platelike crystals and extrafibrillar needlelike crystals for both the pre- and post-treatment biopsies as well as for the bone from young normal subjects. There was no evidence of increased crystal size or of an increase in extrafibrillar mineral deposition. These observations suggest that intermittent SRNaF and continuous calcium therapy exerts an anabolic action on the skeleton not accompanied by a mineralization defect or an alteration of bone mineral deposition. The use of BEI and TEM holds promise for the study of the pathophysiology and treatment of metabolic bone diseases.

Interdependence of skeletal sclerosis and elevated circulating levels of 1,25-dihydroxyvitamin D in osteopetrotic (op and tl) rats.

PubMed

Popoff, S N; Osier, L K; Zerwekh, J E; Marks, S C

1994-01-01

Osteopetrosis describes a heterogeneous group of inherited, metabolic bone disorders characterized by reduced bone resorption which coexists with elevated circulating levels of 1,25-dihydroxyvitamin D [1,25(OH)2D]. To determine whether or not skeletal sclerosis and high concentrations of 1,25(OH)2D are interdependent, this study used two distinct, nonallelic osteopetrotic mutations in the rat, osteopetrosis (op) and toothless (tl). The op rat is a mutation in which skeletal sclerosis can be cured (mutant) or induced (normal) following the transfer of normal or mutant osteoclast progenitors, respectively. Although these procedures are ineffective in rats of tl stock, infusions of pharmacological doses of macrophage colony-stimulating factor (CSF-1) can stimulate bone resorption and eliminate most of the excess skeletal matrix in tl mutants. This study examined the effects of cure/induction in neonatal mutant/normal rats of op stock and CSF-1 infusions in mutant rats of tl stock on skeletal (bone resorption) and serum [1,25(OH)2D] parameters as a function of time after treatment. Osteopetrotic mutants transplanted (cured) with normal spleen cells demonstrated cellular changes in osteoclast phenotype within 2-3 days followed by histologic and radiographic evidence for increased bone resorption that culminated in a normal appearance of the skeleton by 4 weeks. The markedly elevated serum levels of 1,25(OH)2D observed in untreated mutants fell significantly in transplanted mutants by the end of the first week and were similar to those in normal littermates at 3 and 4 weeks. Normal littermates transplanted (induced) with mutant spleen cells showed a progressive increase in skeletal sclerosis paralleled by significant increases in circulating levels of 1,25(OH)2D.(ABSTRACT TRUNCATED AT 250 WORDS)

A severe combined immunodeficient-hu in vivo mouse model of human primary mantle cell lymphoma.

PubMed

Wang, Michael; Zhang, Liang; Han, Xiaohong; Yang, Jing; Qian, Jianfei; Hong, Sungyoul; Lin, Pei; Shi, Yuankai; Romaguera, Jorge; Kwak, Larry W; Yi, Qing

2008-04-01

To establish a severe combined immunodeficient (SCID)-hu in vivo mouse model of human primary mantle cell lymphoma (MCL) for the study of the biology and novel therapy of human MCL. Primary MCL cells were isolated from spleen, lymph node, bone marrow aspirates, or peripheral blood of six different patients and injected respectively into human bone chips, which had been s.c. implanted in SCID-hu. Circulating human beta(2)-microglobulin in mouse serum was used to monitor the engraftment and growth of patient's MCL cells. H&E staining and immunohistochemical staining with anti-human CD20 and cyclin D1 antibodies were used to confirm the tumor growth and migration. Increasing levels of circulating human beta(2)-microglobulin in mouse serum indicated that the patient's MCL cells were engrafted successfully into human bone chip of SCID-hu mice. The engraftment and growth of patient's MCL cells were dependent on human bone marrow microenvironment. Immunohistochemical staining with anti-human CD20 and cyclin D1 antibodies confirmed that patient's MCL cells were able to not only survive and propagate in the bone marrow microenvironment of the human fetal bone chips, but also similar to the human disease, migrate to lymph nodes, spleen, bone marrow, and gastrointestinal tract of host mice. Treatment of MCL-bearing SCID-hu mice with atiprimod, a novel antitumor compound against the protection of bone marrow stromal cells, induced tumor regression. This is the first human primary MCL animal model that should be useful for the biological and therapeutic research on MCL.

Altered MicroRNA Expression Profile in Exosomes during Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

PubMed Central

Zhang, Shui-Jun; Zhao, Chen; Qiu, Bin-Song; Gu, Hai-Feng; Hong, Jian-Fei; Cao, Li; Chen, Yu; Xia, Bing; Bi, Qin; Wang, Ya-Ping

2014-01-01

The physiological role of microRNAs (miRNAs) in osteoblast differentiation remains elusive. Exosomal miRNAs isolated from human bone marrow-derived mesenchymal stem cells (BMSCs) culture were profiled using miRNA arrays containing probes for 894 human matured miRNAs. Seventy-nine miRNAs (∼8.84%) could be detected in exosomes isolated from BMSC culture supernatants when normalized to endogenous control genes RNU44. Among them, nine exosomal miRNAs were up regulated and 4 miRNAs were under regulated significantly (Relative fold>2, p<0.05) when compared with the values at 0 day with maximum changes at 1 to 7 days. Five miRNAs (miR-199b, miR-218, miR-148a, miR-135b, and miR-221) were further validated and differentially expressed in the individual exosomal samples from hBMSCs cultured at different time points. Bioinformatic analysis by DIANA-mirPath demonstrated that RNA degradation, mRNA surveillance pathway, Wnt signaling pathway, RNA transport were the most prominent pathways enriched in quantiles with differential exosomal miRNA patterns related to osteogenic differentiation. These data demonstrated exosomal miRNA is a regulator of osteoblast differentiation. PMID:25503309

Finite element modelling of Plantar Fascia response during running on different surface types

NASA Astrophysics Data System (ADS)

Razak, A. H. A.; Basaruddin, K. S.; Salleh, A. F.; Rusli, W. M. R.; Hashim, M. S. M.; Daud, R.

2017-10-01

Plantar fascia is a ligament found in human foot structure located beneath the skin of human foot that functioning to stabilize longitudinal arch of human foot during standing and normal gait. To perform direct experiment on plantar fascia seems very difficult since the structure located underneath the soft tissue. The aim of this study is to develop a finite element (FE) model of foot with plantar fascia and investigate the effect of the surface hardness on biomechanical response of plantar fascia during running. The plantar fascia model was developed using Solidworks 2015 according to the bone structure of foot model that was obtained from Turbosquid database. Boundary conditions were set out based on the data obtained from experiment of ground reaction force response during running on different surface hardness. The finite element analysis was performed using Ansys 14. The results found that the peak of stress and strain distribution were occur on the insertion of plantar fascia to bone especially on calcaneal area. Plantar fascia became stiffer with increment of Young’s modulus value and was able to resist more loads. Strain of plantar fascia was decreased when Young’s modulus increased with the same amount of loading.

Protective Role of Eosinophils and TNFa after Ozone Inhalation.

PubMed

Fryer, Allison D; Jacoby, David B; Wicher, Sarah A

2017-03-01

Exposure to ozone induces deleterious responses in the airways that include shortness of breath, inflammation, and bronchoconstriction. People with asthma have increased airway sensitivity to ozone and other irritants. Dr. Allison Fryer and colleagues addressed how exposure to ozone affects the immune and physiological responses in guinea pigs. Guinea pigs are considered a useful animal model for studies of respiratory and physiological responses in humans; their response to airborne allergens is similar to that in humans and shares some features of allergic asthma. Fryer and colleagues had previously observed that within 24 hours of exposure, ozone not only induced bronchoconstriction but also stimulated the production of new cells in the bone marrow, where all white blood cells develop. As a result of ozone exposure, increased numbers of newly synthesized white blood cells, particularly eosinophils, moved into the blood and lungs. The central hypothesis of the current study was that newly synthesized eosinophils recruited to the lungs 3 days after ozone exposure were beneficial to the animals because they reduced ozoneinduced bronchoconstriction. The investigators also hypothesized that the beneficial effect seen in normal (nonsensitized) animals was lost in animals that had been injected with an allergen, ovalbumin (sensitized). They also planned to explore the effects of inhibitors of certain cytokines (cellsignaling molecules). Immune responses in sensitized animals are dominated by a Th2 pattern, which is characterized by the synthesis of cytokines (interleukin [IL]-4, IL-5, and IL-13) and the Th2 subset of CD4+ T lymphocytes and the cells they activate (predominantly eosinophils, and B lymphocytes that switch to making immunoglobulin E [IgE]). Thus, sensitized animals were used as a model of allergic humans, whose immune responses tend to be dominated by IgE. Fryer and colleagues exposed normal and sensitized (allergic) guinea pigs to 2 ppm ozone or filtered air for 4 hours and measured changes in cell numbers and airway responses 1 or 3 days later. They counted the numbers of eosinophils and other white blood cells (macrophages, neutrophils, and lymphocytes) in bone marrow, blood, and bronchoalveolar lung lavage fluid. The investigators also measured important physiological responses, including bronchoconstriction. Some animals were pretreated with etanercept and monoclonal anti-IL-5, which block tumor necrosis factor-a (TNFa) and IL-5, respectively. TNFa and IL-5 blockers have been used to treat patients with asthma. A key feature of the study was a technique to distinguish which white blood cells were synthesized after exposure from those that already existed, by injecting animals with bromodeoxyuridine (BrdU). BrdU is a thymidine analogue that is incorporated into the DNA of dividing cells, serving as a marker of newly produced cells. Therefore, a snapshot can be obtained of the proportion of newly synthesized (BrdU-positive) versus pre-existing (BrdU-negative) cell types. 1. Allergic and normal animals differed in the time course of bronchoconstriction and changes in cell types after ozone exposure. In normal animals, bronchoconstriction increased substantially at day 1 but decreased by day 3 after ozone exposure. In contrast, in allergic animals bronchoconstriction remained high at day 3. Ozone also increased the percentage of newly formed, BrdU2 positive eosinophils in the bone marrow and lungs of normal but not allergic animals. 2. Pretreatment with the TNFa blocker etanercept had complex effects, which differed between normal and allergic animals. In normal animals, etanercept decreased ozone-induced new synthesis of eosinophils in the bone marrow and blocked eosinophil migration to the lung; it also increased bronchoconstriction at day 3 (relative to day 1 without etanercept). In allergic animals, etanercept had no effect on any cell type in the bone marrow or lung after exposure to ozone and did not change bronchoconstriction compared with allergic animals not treated with etanercept. Etanercept tended to increase the numbers of blood monocytes and lymphocytes in air- and ozone-exposed normal and allergic animals at day 3, but had no effect on eosinophils in blood at this time point. This was one of the few statistically significant findings in the blood of exposed animals in the study. 3. Anti-IL-5 reduced bronchoconstriction at day 3 after exposure of allergic animals to ozone. In contrast, bronchoconstriction was greatly increased in normal animals treated with anti-IL-5. Fryer and colleagues explored the airway and cellular responses in guinea pigs exposed to ozone. The HEI Review Committee, which conducted an independent review of the study, agreed that the findings supported the authors’ hypothesis (1) that exposure to ozone stimulates production of eosinophils in bone marrow, (2) that these newly formed eosinophils migrate to the lungs, and (3) that those eosinophils play a delayed but potentially beneficial role in reducing ozone-induced inflammation in the airways of healthy normal animals, but not in allergen-sensitized animals. The Committee also agreed that guinea pigs were a good model for studying responses to an allergen, because a major subtype of asthma (the high Th2 or allergic type) is associated with high levels of eosinophils in the blood. A novel finding was that the TNFa blocker etanercept decreased ozone-induced formation of eosinophils in the bone marrow and blocked eosinophil migration to the lung in normal animals. However, because injecting etanercept had little effect on eosinophils and did not decrease bronchoconstriction in allergic guinea pigs, the potential for treating patients with allergic asthma with TNFa blockers is uncertain. This is consistent with the poor performance of TNFa blockers in clinical studies of asthma treatment. Blocking the cytokine IL-5 with an anti-IL-5 antibody substantially decreased bronchoconstriction in sensitized animals. This suggests that therapies targeting IL-5 and eosinophils would be promising in at least some types of asthma. The Committee expressed caution toward experiments with cytokine blockers, both in animal models and humans, because such blockers are often not specific to a particular cell type and may differ at different sites in the body. Without further detailed confirmation of the effects of the blockers, interpreting these experiments can be challenging. The Committee concluded that the study by Fryer and colleagues raises several intriguing directions for future research, including exploring ways in which newly formed eosinophils differ from pre-existing ones, and how such findings apply to humans with allergy or asthma.

Histomorphological analysis of the variability of the human skeleton: forensic implications.

PubMed

Cummaudo, Marco; Cappella, Annalisa; Biraghi, Miranda; Raffone, Caterina; Màrquez-Grant, Nicholas; Cattaneo, Cristina

2018-01-20

One of the fundamental questions in forensic medicine and anthropology is whether or not a bone or bone fragment is human. Surprisingly at times for the extreme degradation of the bone (charred, old), DNA cannot be successfully performed and one must turn to other methods. Histological analysis at times can be proposed. However, the variability of a single human skeleton has never been tested. Forty-nine thin sections of long, flat, irregular and short bones were obtained from a well-preserved medieval adult human skeleton. A qualitative histomorphological analysis was performed in order to assess the presence of primary and secondary bone and the presence, absence and orientation of vascular canals. No histological sections exhibited woven or fibro-lamellar bone. Long bones showed a higher variability with an alternation within the same section of areas characterized by tightly packed secondary osteons and areas with scattered secondary osteons immersed in a lamellar matrix. Flat and irregular bones appeared to be characterized by a greater uniformity with scattered osteons in abundant interstitial lamellae. Some cases of "osteon banding" and "drifting osteons" were observed. Although Haversian bone represent the most frequent pattern, a histomorphological variability between different bones of the same individual, in different portions of the same bone, and in different parts of the same section has been observed. Therefore, the present study has highlighted the importance of extending research to whole skeletons without focusing only on single bones, in order to have a better understanding of the histological variability of both human and non-human bone.

Do vegetarians have a normal bone mass?

PubMed

New, Susan A

2004-09-01

Public health strategies targeting the prevention of poor bone health on a population-wide basis are urgently required, with particular emphasis being placed on modifiable factors such as nutrition. The aim of this review was to assess the impact of a vegetarian diet on indices of skeletal integrity to address specifically whether vegetarians have a normal bone mass. Analysis of existing literature, through a combination of observational, clinical and intervention studies were assessed in relation to bone health for the following: lacto-ovo-vegetarian and vegan diets versus omnivorous, predominantly meat diets, consumption of animal versus vegetable protein, and fruit and vegetable consumption. Mechanisms of action for a dietary "component" effect were examined and other potential dietary differences between vegetarians and non-vegetarians were also explored. Key findings included: (i) no differences in bone health indices between lacto-ovo-vegetarians and omnivores; (ii) conflicting data for protein effects on bone with high protein consumption (particularly without supporting calcium/alkali intakes) and low protein intake (particularly with respect to vegan diets) being detrimental to the skeleton; (iii) growing support for a beneficial effect of fruit and vegetable intake on bone, with mechanisms of action currently remaining unclarified. The impact of a "vegetarian" diet on bone health is a hugely complex area since: 1) components of the diet (such as calcium, protein, alkali, vitamin K, phytoestrogens) may be varied; 2) key lifestyle factors which are important to bone (such as physical activity) may be different; 3) the tools available for assessing consumption of food are relatively weak. However, from data available and given the limitations stipulated above, "vegetarians" do certainly appear to have "normal" bone mass. What remains our challenge is to determine what components of a vegetarian diet are of particular benefit to bone, at what levels and under which mechanisms.

A unified theory of bone healing and nonunion: BHN theory.

PubMed

Elliott, D S; Newman, K J H; Forward, D P; Hahn, D M; Ollivere, B; Kojima, K; Handley, R; Rossiter, N D; Wixted, J J; Smith, R M; Moran, C G

2016-07-01

This article presents a unified clinical theory that links established facts about the physiology of bone and homeostasis, with those involved in the healing of fractures and the development of nonunion. The key to this theory is the concept that the tissue that forms in and around a fracture should be considered a specific functional entity. This 'bone-healing unit' produces a physiological response to its biological and mechanical environment, which leads to the normal healing of bone. This tissue responds to mechanical forces and functions according to Wolff's law, Perren's strain theory and Frost's concept of the "mechanostat". In response to the local mechanical environment, the bone-healing unit normally changes with time, producing different tissues that can tolerate various levels of strain. The normal result is the formation of bone that bridges the fracture - healing by callus. Nonunion occurs when the bone-healing unit fails either due to mechanical or biological problems or a combination of both. In clinical practice, the majority of nonunions are due to mechanical problems with instability, resulting in too much strain at the fracture site. In most nonunions, there is an intact bone-healing unit. We suggest that this maintains its biological potential to heal, but fails to function due to the mechanical conditions. The theory predicts the healing pattern of multifragmentary fractures and the observed morphological characteristics of different nonunions. It suggests that the majority of nonunions will heal if the correct mechanical environment is produced by surgery, without the need for biological adjuncts such as autologous bone graft. Cite this article: Bone Joint J 2016;98-B:884-91. ©2016 The British Editorial Society of Bone & Joint Surgery.

The safety of bone allografts used in dentistry: a review.

PubMed

Holtzclaw, Dan; Toscano, Nicholas; Eisenlohr, Lisa; Callan, Don

2008-09-01

Recent media reports concerning "stolen body parts" have shaken the public's trust in the safety of and the use of ethical practices involving human allografts. The authors provide a comprehensive review of the safety aspects of human bone allografts. The authors reviewed U.S. government regulations, industry standards, independent industry association guidelines, company guidelines and scientific articles related to the use of human bone allografts in the practice of dentistry published in the English language. The use of human bone allografts in the practice of dentistry involves the steps of procurement, processing, use and tracking. Rigorous donor screening and aseptic proprietary processing programs have rendered the use of human bone allografts safe and effective as a treatment option. When purchasing human bone allografts for the practice of dentistry, one should choose products accredited by the American Association of Tissue Banks for meeting uniformly high safety and quality control measures. Knowledge of human bone allograft procurement, processing, use and tracking procedures may allow dental clinicians to better educate their patients and address concerns about this valuable treatment option.

Biotechnology

NASA Image and Video Library

2002-07-31

This diagram shows the normal pathways of calcium movement in the body and indicates changes (green arrows) seen during preliminary space flight experiments. Calcium plays a central role because 1) it gives strength and structure to bone and 2) all types of cells require it to function normally. To better understand how and why weightlessness induces bone loss, astronauts have participated in a study of calcium kinetics -- that is, the movement of calcium through the body, including absorption from food, and its role in the formation and breakdown of bone.

[High prevalence of osteoporosis in asymptomatic postmenopausal Mapuche women].

PubMed

Ponce, Lucía; Larenas, Gladys; Riedemann, Pablo

2002-12-01

Genetic and environmental factors are responsible for variations in the frequency of osteoporosis. Prevalence of osteoporosis in Mapuche women (native Chileans) is unknown. To assess the prevalence and risk factors for osteoporosis in Mapuche women. A random sample of 95 asymptomatic postmenopausal Mapuche females, stratified by age, was studied. Women with diseases or medications that could interfere with calcium metabolism were excluded. Spine and femoral neck bone mass density was determined using a Lunar DPX Alpha densitometer. Seventeen percent of women had normal bone mineral density in both spine and femoral neck. In the spine, 25.3% had a normal bone mineral density, 17.9% had osteopenia and 56.8% had osteoporosis. In the femoral neck, 34.7% had a normal bone mineral density, 57.9% had osteopenia, and 7.4% had osteoporosis. There was a positive correlation between bone mineral density and body mass index. Women with more than one hour per day of physical activity, had a significantly lower proportion of osteopenia or osteoporosis. No association between bone mineral density and parity or calcium intake, was observed. There is a high prevalence of osteopenia and osteoporosis among Mapuche women. Osteoporosis was associated with low body mass index.

BMP-2-regenerated calvarial bone: a biomechanical appraisal in a large animal model.

PubMed

Cray, James; Henderson, Sarah E; Smith, Darren M; Kinsella, Christopher R; Bykowski, Michael; Cooper, Gregory M; Almarza, Alejandro J; Losee, Joseph E

2014-11-01

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is gaining popularity in craniofacial applications. Calvarial defects are, under normal circumstances, subjected to only minimal levels of the biomechanical stresses known to play an important role in osteogenesis, yet regenerated calvarial bone must be capable of withstanding traumatic forces such that the underlying neurocapsule is protected. The aim of this study is to, for the first time, assess the biomechanical properties of calvarial bone regenerated with derivations of a commercially available rhBMP-2-based system. Standardized calvarial defects were created in 23 adult male canines. These defects were treated with rhBMP-2 on one of several carriers. After 24 weeks, the biomechanical properties of the rhBMP-2-generated bone were compared to those of controls with a modified punch-out test (Bluehill 2; Instron, Norwood, Mass) and compared using a paired nonparametric analyses (SPSS, 17.0, Chicago, Ill). In a previously published report, defects across all the rhBMP-2 therapy groups were observed to have a mean rate of 99.5% radio-opacity at 24 weeks indicating nearly full bony coverage of the calvarial defect (compared to 32.7% in surgical controls). For ultimate load, ultimate energy, and first peak energy, there were significant differences (P<0.05) with the control native bone having more robust biomechanical properties than the rhBMP-2-generated bone. We conclude from these findings that rhBMP-2-generated calvarial bone is significantly less protective against trauma than native bone at 6 months. Further investigation is required to assess the efficacy of rhBMP-2 in healing calvarial defects in the longer term.

Evaluation of tibolone administration in bone architectural by MicroCT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carvalho, A. C. B.; Henriques, H. N.; Granjeiro, J. M.

Elderly women are at higher risk for hip fracture because of additional and relatively rapid bone loss due to estrogen deficiency by loss of the ovarian function and a longer average life span than men. The early application of agents that suppress the increase in bone turnover due to estrogen deficiency is essential to prevent bone loss and reduce the risk of osteoporosis. Some advanced imaging techniques may be required to investigate osteoporosis. X-ray micro-computed tomography has been used to generate high-resolution 3D images of cancellous and cortical bone morphology from normal and pathologic human and animal specimens. The aimmore » of this study is to verify the effects of tibolone administration by evaluating the trabecular bone region. The experiment was performed on two groups of rats previously ovariectomized in which one received tibolone while the other did not. Tibolone administration (1 mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs were collected. The scan was obtained using a Hamamatsu 10 Mp camera with a pixel size of 11.59 {mu}m and trabecular region in the right femoral head were quantified. All results were statistically evaluated with significance set at P<0.05%. Tibolone administration was shown to be beneficial in some analysis of the femoral head, performing higher bone volume and reducing the porosity when compared to ovariectomized. It can be concluded that tibolone administered to ovariectomized rats significantly preserved bone mass in the femoral head and microtomography was an efficient method to identify bone loss process and to evaluate potential therapies, as tibolone administration. (authors)« less

Postnatal soluble FGFR3 therapy rescues achondroplasia symptoms and restores bone growth in mice.

PubMed

Garcia, Stéphanie; Dirat, Béatrice; Tognacci, Thomas; Rochet, Nathalie; Mouska, Xavier; Bonnafous, Stéphanie; Patouraux, Stéphanie; Tran, Albert; Gual, Philippe; Le Marchand-Brustel, Yannick; Gennero, Isabelle; Gouze, Elvire

2013-09-18

Achondroplasia is a rare genetic disease characterized by abnormal bone development, resulting in short stature. It is caused by a single point mutation in the gene coding for fibroblast growth factor receptor 3 (FGFR3), which leads to prolonged activation upon ligand binding. To prevent excessive intracellular signaling and rescue the symptoms of achondroplasia, we have developed a recombinant protein therapeutic approach using a soluble form of human FGFR3 (sFGFR3), which acts as a decoy receptor and prevents FGF from binding to mutant FGFR3. sFGFR3 was injected subcutaneously to newborn Fgfr3(ach/+) mice-the mouse model of achondroplasia-twice per week throughout the growth period during 3 weeks. Effective maturation of growth plate chondrocytes was restored in bones of treated mice, with a dose-dependent enhancement of skeletal growth in Fgfr3(ach/+) mice. This resulted in normal stature and a significant decrease in mortality and associated complications, without any evidence of toxicity. These results describe a new approach for restoring bone growth and suggest that sFGFR3 could be a potential therapy for children with achondroplasia and related disorders.

Processing strategies for smart electroconductive carbon nanotube-based bioceramic bone grafts

NASA Astrophysics Data System (ADS)

Mata, D.; Oliveira, F. J.; Ferreira, N. M.; Araújo, R. F.; Fernandes, A. J. S.; Lopes, M. A.; Gomes, P. S.; Fernandes, M. H.; Silva, R. F.

2014-04-01

Electroconductive bone grafts have been designed to control bone regeneration. Contrary to polymeric matrices, the translation of the carbon nanotube (CNT) electroconductivity into oxide ceramics is challenging due to the CNT oxidation during sintering. Sintering strategies involving reactive-bed pressureless sintering (RB + P) and hot-pressing (HP) were optimized towards prevention of CNT oxidation in glass/hydroxyapatite (HA) matrices. Both showed CNT retentions up to 80%, even at 1300 °C, yielding an increase of the electroconductivity in ten orders of magnitude relative to the matrix. The RB + P CNT compacts showed higher electroconductivity by ˜170% than the HP ones due to the lower damage to CNTs of the former route. Even so, highly reproducible conductivities with statistical variation below 5% and dense compacts up to 96% were only obtained by HP. The hot-pressed CNT compacts possessed no acute toxicity in a human osteoblastic cell line. A normal cellular adhesion and a marked orientation of the cell growth were observed over the CNT composites, with a proliferation/differentiation relationship favouring osteoblastic functional activity. These sintering strategies offer new insights into the sintering of electroconductive CNT containing bioactive ceramics with unlimited geometries for electrotherapy of the bone tissue.

Estrogenic Activity Including Bone Enhancement and Effect on Lipid Profile of Luteolin-7-O-glucoside Isolated from Trifolium alexandrinum L. in Ovariectomized Rats.

PubMed

Ammar, N M; El-Hawary, S S; Mohamed, D A; El-Halawany, A M; El-Anssary, A A; El-Kassem, L T Abou; Hussein, R A; Jaleel, G A Abdel; El-Dosoky, A H

2016-05-01

Luteolin-7-O-glycoside (LG), an abundant component in many edible plants, was found to be one of the major constituents of the aqueous methanol extract of Trifolium alexandrinum L. family Fabaceae, a fodder plant widely cultivated in Egypt. The estrogenic activity of LG concerning the effect on uterotrophy, lipid profile, weight gain and bone enhancement activity was determined in ovariectomized rat model at a dose of 5 mg/kg. Luteolin-7-O-glycoside showed significant estrogenic effect through the preservation of normal uterine weight and plasma estradiol level. It also significantly inhibited the bone turnover markers plasma bone-specific alkaline phosphatase, plasma osteocalsin, type I procollagen N-terminal, and C-telopeptide of type II collagen levels. It induced a significant improvement in plasma lipid profile. The effect of LG was comparable with estradiol with lower effect on uterine weight. Liver and kidney functions revealed a wide safety of LG at this dose level. The present study revealed that LG may be a promising hormone replacement therapy after being examined thoroughly on human. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

BMP7 Induces Dormancy of Prostatic Tumor Stem Cell in Bone

DTIC Science & Technology

2012-10-01

the upper back of nude mice. Recombinant human BMP7 was peritumorally injected daily after implantation. Tumor growth was monitored weekly by...of BMP7 was administrated daily through i.v. after intracardiac injection of CSCs from PC3mm or C4-2B cells to the mice. As shown in Figure 5A...mice, and then BMP7 was administrated daily . BLI of representative mice in each group six weeks after implantation (A). Normalized BLI signals

Mineral density volume gradients in normal and diseased human tissues

DOE PAGES

Djomehri, Sabra I.; Candell, Susan; Case, Thomas; ...

2015-04-09

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

Mineral density volume gradients in normal and diseased human tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djomehri, Sabra I.; Candell, Susan; Case, Thomas

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

Mineral density volume gradients in normal and diseased human tissues.

PubMed

Djomehri, Sabra I; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W; Yun, Wenbing; Lau, S H; Webb, Samuel; Ho, Sunita P

2015-01-01

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095 mg/cc, bone: 570-1415 mg/cc, cementum: 1240-1340 mg/cc, dentin: 1480-1590 mg/cc, cementum affected by periodontitis: 1100-1220 mg/cc, hypomineralized carious dentin: 345-1450 mg/cc, hypermineralized carious dentin: 1815-2740 mg/cc, and dental calculus: 1290-1770 mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.

Mineral Density Volume Gradients in Normal and Diseased Human Tissues

PubMed Central

Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.

2015-01-01

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations. PMID:25856386

Perfluoroalkyl substances in human bone: concentrations in bones and effects on bone cell differentiation.

PubMed

Koskela, A; Koponen, J; Lehenkari, P; Viluksela, M; Korkalainen, M; Tuukkanen, J

2017-07-28

Perfluoroalkyl substances (PFAS), including two most commonly studied compounds perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are widely distributed environmental pollutants, used extensively earlier. Due to their toxicological effects the use of PFAS is now regulated. Based on earlier studies on PFOA's distribution in bone and bone marrow in mice, we investigated PFAS levels and their possible link to bone microarchitecture of human femoral bone samples (n = 18). Soft tissue and bone biopsies were also taken from a 49-year old female cadaver for PFAS analyses. We also studied how PFOA exposure affects differentiation of human osteoblasts and osteoclasts. PFAS were detectable from all dry bone and bone marrow samples, PFOS and PFOA being the most prominent. In cadaver biopsies, lungs and liver contained the highest concentrations of PFAS, whereas PFAS were absent in bone marrow. Perfluorononanoic acid (PFNA) was present in the bones, PFOA and PFOS were absent. In vitro results showed no disturbance in osteogenic differentiation after PFOA exposure, but in osteoclasts, lower concentrations led to increased resorption, which eventually dropped to zero after increase in PFOA concentration. In conclusion, PFAS are present in bone and have the potential to affect human bone cells partly at environmentally relevant concentrations.

Human bone hardness seems to depend on tissue type but not on anatomical site in the long bones of an old subject.

PubMed

Ohman, Caroline; Zwierzak, Iwona; Baleani, Massimiliano; Viceconti, Marco

2013-02-01

It has been hypothesised that among different human subjects, the bone tissue quality varies as a function of the bone segment morphology. The aim of this study was to assess and compare the quality, evaluated in terms of hardness of packages of lamellae, of cortical and trabecular bones, at different anatomical sites within the human skeleton. The contralateral six long bones of an old human subject were indented at different levels along the diaphysis and at both epiphyses of each bone. Hardness value, which is correlated to the degree of mineralisation, of both cortical and trabecular bone tissues was calculated for each indentation location. It was found that the cortical bone tissue was harder (+18%) than the trabecular one. In general, the bone hardness was found to be locally highly heterogeneous. In fact, considering one single slice obtained for a bone segment, the coefficient of variation of the hardness values was up to 12% for cortical bone and up to 17% for trabecular bone. However, the tissue hardness was on average quite homogeneous within and among the long bones of the studied donor, although differences up to 9% among levels and up to 7% among bone segments were found. These findings seem not to support the mentioned hypothesis, at least not for the long bones of an old subject.

High-strength mineralized collagen artificial bone

NASA Astrophysics Data System (ADS)

Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

2014-03-01

Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

Interleukin 1 increases thymidine labeling index of normal tissues of mic but not the tumor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaghloul, M.S.; Dorie, M.J.; Kallman, R.F.

1994-07-01

This study was conducted to investigate the action of human recombinant interleukin 1 as a radioprotector for different mouse normal cells other than bone marrow cells. Semi-continuous injections of tritiated thymidine were administered every 6 h, over 24 h to determine thymidine labeling index. Mice were injected with recombinant human interleukin 1 24 h prior to tritiated thymidine and were compared to control animals that did not receive interleukin 1. Mice were killed 1 h after the last thymidine injection. The 24 h thymidine labeling index for normal tissues and RIF-1 tumor was determined. Labeling indices were also determined 1-14more » days after a series of fractionated irradiations with or without pretreatment with a single dose of interleukin 1 administered 24 h prior to the first radiation. The thymidine labeling index of normal tissues was higher following the injection of recombinant human interleukin 1 24 h before radiolabeling. This was found in all normal tissues tested. The thymidine labeling index of RIF-1 fibrosarcoma was not affected by interleukin 1 injection. A single interleukin 1 injection 24 h before the first radiation fraction also increased the thymidine labeling indices of normal tissues after localized fractionated irradiation. The thymidine labeling index of RIF-1 tumor was not increased by interleukin 1 administration except after relatively high radiation doses (20 Gy in five fractions). The ability of interleukin 1 to enhance the thymidine labeling index declined after the first day following the completion of fractionated irradiation. Recombinant human interleukin 1 increased the 24 h thymidine labeling index in normal tissues in mice, but not in RIF-1 tumor. Fractionated irradiation could maintain the effect of a single dose of interleukin 1, administered 24 h prior to the first fraction, up to 24 h after the end of radiation. 25 refs., 3 figs., 1 tab.« less

Altered thermogenesis and impaired bone remodeling in Misty mice

PubMed Central

Motyl, Katherine J; Bishop, Kathleen A; DeMambro, Victoria E; Bornstein, Sheila A; Le, Phuong; Kawai, Masanobu; Lotinun, Sutada; Horowitz, Mark C; Baron, Roland; Bouxsein, Mary L; Rosen, Clifford J

2013-01-01

Fat mass may be modulated by the number of brown-like adipocytes in white adipose tissue (WAT) in humans and rodents. Bone remodeling is dependent on systemic energy metabolism and, with age, bone remodeling becomes uncoupled and brown adipose tissue (BAT) function declines. To test the interaction between BAT and bone, we employed Misty (m/m) mice, which were reported be deficient in BAT. We found that Misty mice have accelerated age-related trabecular bone loss and impaired brown fat function (including reduced temperature, lower expression of Pgc1a and less sympathetic innervation compared to wildtype (+/+)). Despite reduced BAT function, Misty mice had normal core body temperature, suggesting heat is produced from other sources. Indeed, upon acute cold exposure (4°C for 6 hr), inguinal WAT from Misty mice compensated for BAT dysfunction by increasing expression of Acadl, Pgc1a, Dio2 and other thermogenic genes. Interestingly, acute cold exposure also decreased Runx2 and increased Rankl expression in Misty bone, but only Runx2 was decreased in wildtype. Browning of WAT is under the control of the sympathetic nervous system (SNS) and, if present at room temperature, could impact bone metabolism. To test whether SNS activity could be responsible for accelerated trabecular bone loss, we treated wildtype and Misty mice with the β-blocker, propranolol. As predicted, propranolol slowed trabecular BV/TV loss in the distal femur of Misty mice without affecting wildtype. Finally, the Misty mutation (a truncation of DOCK7) also has a significant cell-autonomous role. We found DOCK7 expression in whole bone and osteoblasts. Primary osteoblast differentiation from Misty calvaria was impaired, demonstrating a novel role for DOCK7 in bone remodeling. Despite the multifaceted effects of the Misty mutation, we have shown that impaired brown fat function leads to altered SNS activity and bone loss, and for the first time that cold exposure negatively affects bone remodeling. PMID:23553822

Effects of Recombinant Human Lactoferrin on Osteoblast Growth and Bone Status in Piglets.

PubMed

Li, Qiuling; Zhao, Jie; Hu, Wenping; Wang, Jianwu; Yu, Tian; Dai, Yunping; Li, Ning

2018-04-03

Lactoferrin (LF), an ~80 kDa iron-binding glycoprotein, modulates many biological effects, including antimicrobial and immunomodulatory activities. Recently, it was shown that LF also regulates bone cell activity, suggesting its therapeutic effect on postmenopausal bone loss. However, a minimal amount is known regarding the effects of recombinant human LF (rhLF) supplementation on bone status in young healthy infants. We found osteoblast cell differentiation was significantly promoted in vitro. Furthermore, treatment of human osteoblast cells with rhLF rapidly induced phosphorylation of p44/p42 mitogen-activated protein kinase (p44/p42 MAPK, ERK1/2). In order to investigate the effects of rhLF on bone status in vivo, we used a piglet model, which is a useful model for human infants. Piglets were supplemented with rhLF milk for 30 days. Bone formation markers, Serum calcium concentration, bone mineral density (BMD), bone mineral content (BMC), tibia bone strength, and the overall metabolite profile analysis showed that rhLF was advantageous to the bone growth in piglets. These findings suggest that rhLF supplementation benefits neonate bone health by modulating bone formation.

In vivo competitive studies between normal and common gamma chain-defective bone marrow cells: implications for gene therapy.

PubMed

Otsu, M; Sugamura, K; Candotti, F

2000-09-20

Corrective gene transfer into hematopoietic stem cells (HSCs) is being investigated as therapy for X-linked severe combined immunodeficiency (XSCID) and it is hoped that selective advantage of gene-corrected HSCs will help in achieving full immune reconstitution after treatment. Lines of evidence from the results of allogeneic bone marrow transplantation in patients with XSCID support this hypothesis that, however, has not been rigorously tested in an experimental system. We studied the competition kinetics between normal and XSCID bone marrow (BM) cells using a murine bone marrow transplantation (BMT) model. For easy chimerism determination, we used genetic marking with retrovirus-mediated expression of the enhanced green fluorescent protein (EGFP). We found that XSCID BM cells were able to compete with normal BM cells for engraftment of myeloid lineages in a dose-dependent manner, whereas we observed selective repopulation of T, B, and NK cells deriving from normal BM cells. This was true despite the evidence of competitive engraftment of XSCID lineage marker-negative/c-Kit-positive (Lin-/c-Kit+) cells in the bone marrow of treated animals. From these results we extrapolate that genetic correction of XSCID HSCs will result in selective advantage of gene-corrected lymphoid lineages with consequent restoration of lymphocyte populations and high probability of clinical benefit.

Three-dimensional ultrasonography measurement of fetal nasal bone length during the midtrimester in Taiwanese women.

PubMed

Yang, Pei-Yin; Wu, Joung-Liang; Yeh, Guang-Perng; Tsung-Che Hsieh, Charles

2012-09-01

To evaluate the normal range of the fetal nasal bone length (NBL) in Taiwanese women using three-dimensional (3D) ultrasound, and compare the NBL of normal fetuses with Down syndrome to determine its significance in screening for trisomy 21. A total of 102 consecutive fetuses and another 7 fetuses with trisomy 21, determined by karyotyping at 15-22 weeks' gestation, were evaluated with 3D ultrasound before amniocentesis at Changhua Christian Hospital between November 2003 and April 2004. The normal range for NBL in the second trimester in the Taiwanese population was investigated, and a linear relationship with gestational age was noted. The NBL increased with advancing gestational age (NBL in cm=0.0264×gestational age in weeks -0.042 (R(2)=0.2416). The median of the biparietal diameter/nasal bone length ratio had a stable value which tended to change minimally between 15 and 22 weeks of gestation. Chromosomally normal fetuses had statistically longer nasal bones than fetuses with Down syndrome (p=0.014). We present a reference range for 3D ultrasound measurement of the fetal NBL. A short nasal bone at 15 to 22 weeks is associated with a high risk of trisomy 21. Copyright © 2012. Published by Elsevier B.V.

Standardized quantitative measurements of wrist cartilage in healthy humans using 3T magnetic resonance imaging

PubMed Central

Zink, Jean-Vincent; Souteyrand, Philippe; Guis, Sandrine; Chagnaud, Christophe; Fur, Yann Le; Militianu, Daniela; Mattei, Jean-Pierre; Rozenbaum, Michael; Rosner, Itzhak; Guye, Maxime; Bernard, Monique; Bendahan, David

2015-01-01

AIM: To quantify the wrist cartilage cross-sectional area in humans from a 3D magnetic resonance imaging (MRI) dataset and to assess the corresponding reproducibility. METHODS: The study was conducted in 14 healthy volunteers (6 females and 8 males) between 30 and 58 years old and devoid of articular pain. Subjects were asked to lie down in the supine position with the right hand positioned above the pelvic region on top of a home-built rigid platform attached to the scanner bed. The wrist was wrapped with a flexible surface coil. MRI investigations were performed at 3T (Verio-Siemens) using volume interpolated breath hold examination (VIBE) and dual echo steady state (DESS) MRI sequences. Cartilage cross sectional area (CSA) was measured on a slice of interest selected from a 3D dataset of the entire carpus and metacarpal-phalangeal areas on the basis of anatomical criteria using conventional image processing radiology software. Cartilage cross-sectional areas between opposite bones in the carpal region were manually selected and quantified using a thresholding method. RESULTS: Cartilage CSA measurements performed on a selected predefined slice were 292.4 ± 39 mm2 using the VIBE sequence and slightly lower, 270.4 ± 50.6 mm2, with the DESS sequence. The inter (14.1%) and intra (2.4%) subject variability was similar for both MRI methods. The coefficients of variation computed for the repeated measurements were also comparable for the VIBE (2.4%) and the DESS (4.8%) sequences. The carpus length averaged over the group was 37.5 ± 2.8 mm with a 7.45% between-subjects coefficient of variation. Of note, wrist cartilage CSA measured with either the VIBE or the DESS sequences was linearly related to the carpal bone length. The variability between subjects was significantly reduced to 8.4% when the CSA was normalized with respect to the carpal bone length. CONCLUSION: The ratio between wrist cartilage CSA and carpal bone length is a highly reproducible standardized measurement which normalizes the natural diversity between individuals. PMID:26396941

Bone Quest - A Space-Based Science and Health Education Unit

NASA Technical Reports Server (NTRS)

Smith, Scott M.; David-Street, Janis E.; Abrams, Steve A.

2000-01-01

This proposal addresses the need for effective and innovative science and health education materials that focus on space bone biology and its implications for bone health on Earth. The focus of these materials, bone biology and health, will increase science knowledge as well as health awareness. Current investigations of the bone loss observed after long-duration space missions provide a link between studies of bone health in space, and studies of osteoporosis, a disease characterized by bone loss and progressive skeletal weakness. The overall goal of this project is to design and develop web-based and print-based materials for high school science students, that will address the following: a) knowledge of normal bone biology and bone biology in a microgravity environment; b) knowledge of osteoporosis; c) knowledge of treatment modalities for space- and Earth-based bone loss; and d} bone-related nutrition knowledge and behavior. To this end, we propose to design and develop a Bone Biology Tutorial which will instruct students about normal bone biology, bone biology in a microgravity environment, osteoporosis - its definition, detection, risk factors, and prevention, treatment modalities for space- and Earth-based bone loss, and the importance of nutrition in bone health. Particular emphasis will be placed on current trends in . adolescent nutrition, and their relationships to bone health. Additionally, we propose to design and develop two interactive nutrition/health ' education activities that will allow students to apply the information provided in the Bone Biology Tutorial. In the first, students will apply constructs provided in the Bone Biology Tutorial to design "Bone Health Plans" for space travelers.

Lack of biochemical hypogonadism in elderly Arab males with low bone mineral density disease.

PubMed

Al Attia, Haider M; Jaysundaram, Krishnasamy; Saraj, Fouad

2010-01-01

The aim of the study is to study the relationship between androgen levels and bone mineral density (BMD) in elderly Arab males. Forty-five elderly Arab males underwent Dual X-ray absorptiometry for measurement of BMD. The outcomes were defined as per WHO description. Assays for testosterone (T), gonadotropins (LH and FSH) and estradiol (E2), in the serum were carried out. The ratio of T/LH was used as a surrogate for the cFT assay. We excluded patients receiving hormonal ablation for prostatic neoplasm and patients with chronic liver or renal disease and patients receiving corticosteroids. Twelve were osteoporotic (26.5%); 22 osteopenic (49%); and 11(24.5%) had normal outcome. Osteoporotic patients were significantly older (78.17 +/- 7.59 years) than the osteopenic (70.14 +/- 5.92, P

Maternal perinatal diet induces developmental programming of bone architecture.

PubMed

Devlin, M J; Grasemann, C; Cloutier, A M; Louis, L; Alm, C; Palmert, M R; Bouxsein, M L

2013-04-01

Maternal high-fat (HF) diet can alter offspring metabolism via perinatal developmental programming. This study tests the hypothesis that maternal HF diet also induces perinatal programming of offspring bone mass and strength. We compared skeletal acquisition in pups from C57Bl/6J mice fed HF or normal diet from preconception through lactation. Three-week-old male and female pups from HF (HF-N) and normal mothers (N-N) were weaned onto normal diet. Outcomes at 14 and 26 weeks of age included body mass, body composition, whole-body bone mineral content (WBBMC) via peripheral dual-energy X-ray absorptiometry, femoral cortical and trabecular architecture via microcomputed tomography, and glucose tolerance. Female HF-N had normal body mass and glucose tolerance, with lower body fat (%) but higher serum leptin at 14 weeks vs. N-N (P<0.05 for both). WBBMC was 12% lower at 14 weeks and 5% lower at 26 weeks, but trabecular bone volume fraction was 20% higher at 14 weeks in female HF-N vs. N-N (P<0.05 for all). Male HF-N had normal body mass and mildly impaired glucose tolerance, with lower body fat (%) at 14 weeks and lower serum leptin at 26 weeks vs. N-N (P<0.05 for both). Serum insulin was higher at 14 weeks and lower at 26 weeks in HF-N vs. N-N (P<0.05). Trabecular BV/TV was 34% higher and cortical bone area was 6% higher at 14 weeks vs. N-N (P<0.05 for both). These data suggest that maternal HF diet has complex effects on offspring bone, supporting the hypothesis that maternal diet alters postnatal skeletal homeostasis.

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

PubMed

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.

Measurement of Bone Growth in Osteopetrosis

PubMed Central

Sanger, V. L.; Frederickson, T. N.; Morrill, C. C.

1964-01-01

Day-old chicks were injected with 0.2 ml. of a suspension of lymphomatosis virus which was known to cause osteopetrosis in a high percentage of susceptible birds. A comparable number of uninoculated chicks were kept for controls. Alizarin red S was administered for the purpose of marking the bones in order to measure the rate of growth of normal bone and the osteopetrotic bone. The dye was given at 27, 41 and 55 days of age. In this experiment it was found that a layer of normal bone was formed on the surface of the tibia at a rate of 0.25 mm. per week but in the largest osteopetrotic lesion that was found in any chicken spongy bone was formed at a rate greater than 1 mm. per week. Alizarin red S was irritating to tissue and was toxic when given intravenously. ImagesFig. 1.Fig. 2. PMID:17649533

Cortical bone thickening in Type A posterior atlas arch defects: experimental report.

PubMed

Sanchis-Gimeno, Juan A; Llido, Susanna; Guede, David; Martinez-Soriano, Francisco; Ramon Caeiro, Jose; Blanco-Perez, Esther

2017-03-01

To date, no information about the cortical bone microstructural properties in atlas vertebrae with posterior arch defects has been reported. To test if there is an increased cortical bone thickening in atlases with Type A posterior atlas arch defects in an experimental model. Micro-computed tomography (CT) study on cadaveric atlas vertebrae. We analyzed the cortical bone thickness, the cortical volume, and the medullary volume (SkyScan 1172 Bruker micro-CT NV, Kontich, Belgium) in cadaveric dry vertebrae with a Type A atlas arch defect and normal control vertebrae. The micro-CT study revealed significant differences in cortical bone thickness (p=.005), cortical volume (p=.003), and medullary volume (p=.009) values between the normal and the Type A vertebrae. Type A congenital atlas arch defects present a cortical bone thickening that may play a protective role against atlas fractures. Copyright © 2016 Elsevier Inc. All rights reserved.

Apoptosis may determine the release of skeletal alkaline phosphatase activity from human osteoblast-line cells.

PubMed

Farley, J R; Stilt-Coffing, B

2001-01-01

Although quantitative measurement of skeletal alkaline phosphatase (sALP) activity in serum can provide an index of the rate of bone formation, the metabolic process that determines the release of sALP - from the surface of osteoblasts, into circulation-is unknown. The current studies were intended to examine the hypothesis that the release of sALP from human osteoblasts is a consequence of apoptotic cell death. We measured the release of sALP activity from human osteosarcoma (SaOS-2) cells and normal human bone cells, under basal conditions and in response to agents that increased apoptosis (TNF-a, okadiac acid) and agents that inhibit apoptosis (IGF-I, calpain, and caspase inhibitors). Apoptosis was determined by the presence of nucleosomes (histone-associated DNA) in the cytoplasm of the cells by using a commercial kit. The results of these studies showed that TNF-a and okadiac acid caused dose- and time-dependent increases in apoptosis in the SaOS-2 cells (r = 0.78 for doses of TNF-a and r = 0.93 for doses of okadiac acid, P <0.005 for each), with associated decreases in cell layer protein (P <0.05 for each) and concomitant increases in the release of sALP activity (e.g., r = 0.89 for TNF-a and r = 0.75 for okadiac acid, P <0.001 for each). In contrast, caspase and calpain inhibitors reduced apoptosis, increased cell layer protein, and decreased the release of sALP activity (P <0.05 for each). Exposure to IGF-I also decreased apoptosis, in a time- and dose-dependent manner (e.g., r = 0.93, P <0.001 for IGF-I doses), with associated proportional effects to increase cell layer protein (P <0.001) and decrease the release of sALP activity (P <0.001). IGF-I also inhibited the actions of TNF-a and okadiac acid to increase apoptosis and sALP release. The associations between apoptosis and sALP release were not unique to osteosarcoma (i.e., SaOS-2) cells, but also seen with osteoblast-line cells derived from normal human bone. Together, these data demonstrate that the release of sALP activity from human osteoblast-line cells in vitro is associated with, and may be a consequence of, apoptotic cell death. These findings are consistent with the general hypothesis that the appearance of sALP activity in serum may reflect the turnover of osteoblast-line cells.

Serum tumour necrosis factor alpha in osteopenic and osteoporotic postmenopausal females: A cross-sectional study in Pakistan.

PubMed

Murad, Rafat; Shezad, Zahra; Ahmed, Saara; Ashraf, Mussarat; Qadir, Murad; Rehman, Rehana

2018-03-01

To compare biochemical parameters serum tumour necrosis factor alpha, calcium, magnesium, bone-specific alkaline phosphatase and vitamin D in postmenopausal women. This cross-sectional study was carried out from June 2015 to July 2016 at Jinnah Medical and Dental College, Karachi, and comprised postmenopausal women. Bone mineral density done by dual energy X-ray absorptiometryscan categorised subjects by World Health Organisation classification into normal (T score > -1) osteopenic (T score between -1 and -2.5) and osteoporotic (T score < -2.5). Biochemical parameters like tumour necrosis alpha, calcium, magnesium, bone-specific alkaline phosphatase and vitamin D were measured by solid phase enzyme amplified sensitivity immunoassay method. SPSS 16 was used to analyse the data. Of the 146 women, 34(23%) were normal, 93(67%) were osteopenic and 19(13%) were osteoporotic. There was significant difference in mean body mass index, serum tumour necrosis factor alpha and calcium in all the three groups (p<0.01). Significant mean difference was observed in serum calcium levels between normal and osteopenic, and between normal and osteoporotic group (p<0.05 each) without any significant mean difference between osteopenic and osteoporotic groups (p>0.05). A significant difference was observed for mean tumour necrosis factor alpha values between normal and osteoporotic groups (p<0.05). Tumour necrosis factor alpha showed negative correlation with bone mineral density in osteopenic and osteoporotic groups (p>0.05). Increased bone turnover in postmenopausal osteopenic women can be predicted by increased serum cytokine.

Substitutions of aspartic acid for glycine-220 and of arginine for glycine-664 in the triple helix of the pro alpha 1(I) chain of type I procollagen produce lethal osteogenesis imperfecta and disrupt the ability of collagen fibrils to incorporate crystalline hydroxyapatite.

PubMed Central

Culbert, A A; Lowe, M P; Atkinson, M; Byers, P H; Wallis, G A; Kadler, K E

1995-01-01

We identified two infants with lethal (type II) osteogenesis imperfecta (OI) who were heterozygous for mutations in the COL1A1 gene that resulted in substitutions of aspartic acid for glycine at position 220 and arginine for glycine at position 664 in the product of one COL1A1 allele in each individual. In normal age- and site-matched bone, approximately 70% (by number) of the collagen fibrils were encrusted with plate-like crystallites of hydroxyapatite. In contrast, approximately 5% (by number) of the collagen fibrils in the probands' bone contained crystallites. In contrast with normal bone, the c-axes of hydroxyapatite crystallites were sometimes poorly aligned with the long axis of fibrils obtained from OI bone. Chemical analysis showed that the OI samples contained normal amounts of calcium. The probands' bone samples contained type I collagen, overmodified type I collagen and elevated levels of type III and V collagens. On the basis of biochemical and morphological data, the fibrils in the OI samples were co-polymers of normal and mutant collagen. The results are consistent with a model of fibril mineralization in which the presence of abnormal type I collagen prevents normal collagen in the same fibril from incorporating hydroxyapatite crystallites. Images Figure 1 Figure 2 Figure 3 PMID:7487936

Bone remodelling around HA-coated acetabular cups

PubMed Central

Nielsen, P. T.; Søballe, K.

2006-01-01

This study was designed to investigate bone remodelling around the cup in cementless THA. Previous studies indicate an advantage of better sealing of the bone-prosthesis interface by HA/TCP coating of implants, inhibiting polyethylene-induced osteolysis. One hundred patients gave informed consent to participate in a controlled randomized study between porous coated Trilogy versus Trilogy Calcicoat (HA/TCP coated). The cup was inserted in press-fit fixation. The femoral component was a cementless porous coated titanium alloy stem (Bi-Metric), with a modular 28-mm CrCo head. The Harris Hip Score (HHS) and bone mineral density (BMD) determined by DEXA scanning were used to study the effect. Measurements revealed no difference between the two groups after 3 years either in the clinical outcome or in terms of periprosthetic bone density. Patients with a body mass index above normal regained more bone mineral than patients with normal weight. This finding supports the assumption that load is beneficial to bone remodelling. PMID:16761153

[Human stem cells from apical papilla can regenerate dentin-pulp complex].

PubMed

Xiong, Huacui; Chen, Ke; Huang, Yibin; Liu, Caiqi

2013-10-01

To regenerate dentin-pulp complex by tissue engineering with human stem cells from apical papilla cells (SCAP) as the seed cells. SCAP was separated from from normal human impacted third molars with immature roots by outgrowth culture. The cells were then cultured in the differentiation medium for 3 weeks or in normal medium for 60 days, and analyzed for mineralization potential by Alizarin red staining. The osteo/odontogenic markers including alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OC) and dentin sialoprotein (DSP) were investigated by immunofluorescence staining and reverse transcription-polymerase chain reaction. The co-cultured mixture of SCAP and HA/TCP, or HA/TCP alone was implanted subcutaneously on the back of nude mice for 8 weeks, and the implants were collected and examined by HE and immunohistochemical staining. Round alizarin red-positive nodules formed in the isolated cells after cell culture in the differentiation medium for 3 weeks or in normal medium for 60 days with positive staining for osteo/odontogenic markers. SCAP with HA/TCP could regenerate pulp-dentin complex-like tissue in nude mice. The cells near the dentin-like tissue were positive for DSP. No mineral tissue was found in mice receiving HA/TCP implantation. SCAP may serve as a promising seed cell for dentin-pulp complex tissue engineering.

THE RHYTHMIC RANGE OF THE WHITE BLOOD CELLS IN HUMAN, PATHOLOGICAL LEUCOPENIC AND LEUCOCYTIC STATES, WITH A STUDY OF THIRTY-TWO HUMAN BONE MARROWS

PubMed Central

Doan, Charles A.; Zerfas, Leon G.

1927-01-01

In a study of twenty clinical cases with a wide range of diagnoses, repeated total counts of the white cells at 15 minute intervals reveal a large fluctuation at various levels comparable to that found for the normal (1, 2). The granulocytes seem to follow a more or less hourly rhythm, the most marked shift to the left in the Ameth pattern and the moment of greatest percentage of motility coinciding with the peaks. The independence found existing between the peripheral blood concentrations of individual strains of white cells and the red cells, as determined by total and differential counts, their differential response to pathological and pharmacological stimuli, and their normal relative relations, all indicate some separate physiological mechanism of control for each type of cell, either working through, or independently of, their sources of origin. The many factors to which the circulation of the blood, as such, is subject, the complexity of the influences on origin, maturation, delivery, longevity, and destruction of each cell group, the limitations inherent in the present involved, indirect technics of counting, combine to make any single observation subject to grave misinterpretation. The value to the clinician must come in repeated observations, at times when the diagnosis or a therapeutic procedure is in doubt, at frequent intervals, at other times over longer or shorter periods, but always with the relation between consecutive counts, rather than the absolute values, the important point for consideration. Both the red and the white cells probably change their relative concentrations in the peripheral blood from time to time over a considerable range that is quite within normal physiological limits, so that, in theoretical considerations and in practical functional estimations, a zonal concept with adequate individual extremes should always be kept in mind for both physiological and pathological states. A cytological analysis of thirty-two bone marrows from human biopsy and autopsy material shows the striking reciprocity found to exist between the myelocytes and the mature polymorphonuclear leucocytes. This, together with the observed focal uniformity of maturation found in bone marrow, and the periodicity of the fluctuations of the neutrophils in the peripheral blood, leads to the formulation of the hypothesis of a constant functional withdrawal of granulocytes from the peripheral blood with a periodic delivery of new cells from the marrow, which in leucopenia and in leucocytosis represents a depression or a stimulation, respectively, of the normal mechanism. The nature and degree of the response are an approximate index of the cellular factor in the complex of the "resistance" of the particular individual. PMID:19869352

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

PubMed

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.

Anorexia Nervosa and Bone

PubMed Central

Misra, Madhusmita; Klibanski, Anne

2014-01-01

Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure and reduced bone strength, all of which contribute to increased fracture risk., Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising addition concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiologic estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

Octacalcium phosphate collagen composite facilitates bone regeneration of large mandibular bone defect in humans.

PubMed

Kawai, Tadashi; Suzuki, Osamu; Matsui, Keiko; Tanuma, Yuji; Takahashi, Tetsu; Kamakura, Shinji

2017-05-01

Recently it was reported that the implantation of octacalcium phosphate (OCP) and collagen composite (OCP-collagen) was effective at promoting bone healing in small bone defects after cystectomy in humans. In addition, OCP-collagen promoted bone regeneration in a critical-sized bone defect of a rodent or canine model. In this study, OCP-collagen was implanted into a human mandibular bone defect with a longer axis of approximately 40 mm, which was diagnosed as a residual cyst with apical periodontitis. The amount of OCP-collagen implanted was about five times greater than the amounts implanted in previous clinical cases. Postoperative wound healing was satisfactory and no infection or allergic reactions occurred. The OCP-collagen-treated lesion was gradually filled with radio-opaque figures, and the alveolar region occupied the whole of the bone defect 12 months after implantation. This study suggests that OCP-collagen could be a useful bone substitute material for repairing large bone defects in humans that might not heal spontaneously. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Partial Reductions in Mechanical Loading Yield Proportional Changes in Bone Density, Bone Architecture, and Muscle Mass

PubMed Central

Ellman, Rachel; Spatz, Jordan; Cloutier, Alison; Palme, Rupert; Christiansen, Blaine A; Bouxsein, Mary L

2014-01-01

Although the musculoskeletal system is known to be sensitive to changes in its mechanical environment, the relationship between functional adaptation and below-normal mechanical stimuli is not well defined. We investigated bone and muscle adaptation to a range of reduced loading using the partial weight suspension (PWS) system, in which a two-point harness is used to offload a tunable amount of body weight while maintaining quadrupedal locomotion. Skeletally mature female C57Bl/6 mice were exposed to partial weight bearing at 20%, 40%, 70%, or 100% of body weight for 21 days. A hindlimb unloaded (HLU) group was included for comparison in addition to age-matched controls in normal housing. Gait kinematics was measured across the full range of weight bearing, and some minor alterations in gait from PWS were identified. With PWS, bone and muscle changes were generally proportional to the degree of unloading. Specifically, total body and hindlimb bone mineral density, calf muscle mass, trabecular bone volume of the distal femur, and cortical area of the femur midshaft were all linearly related to the degree of unloading. Even a load reduction to 70% of normal weight bearing was associated with significant bone deterioration and muscle atrophy. Weight bearing at 20% did not lead to better bone outcomes than HLU despite less muscle atrophy and presumably greater mechanical stimulus, requiring further investigation. These data confirm that the PWS model is highly effective in applying controllable, reduced, long-term loading that produces predictable, discrete adaptive changes in muscle and bone of the hindlimb. PMID:23165526

Genetically engineered mesenchymal stromal cells produce IL-3 and TPO to further improve human scaffold-based xenograft models.

PubMed

Carretta, Marco; de Boer, Bauke; Jaques, Jenny; Antonelli, Antonella; Horton, Sarah J; Yuan, Huipin; de Bruijn, Joost D; Groen, Richard W J; Vellenga, Edo; Schuringa, Jan Jacob

2017-07-01

Recently, NOD-SCID IL2Rγ -/- (NSG) mice were implanted with human mesenchymal stromal cells (MSCs) in the presence of ceramic scaffolds or Matrigel to mimic the human bone marrow (BM) microenvironment. This approach allowed the engraftment of leukemic samples that failed to engraft in NSG mice without humanized niches and resulted in a better preservation of leukemic stem cell self-renewal properties. To further improve our humanized niche scaffold model, we genetically engineered human MSCs to secrete human interleukin-3 (IL-3) and thrombopoietin (TPO). In vitro, these IL-3- and TPO-producing MSCs were superior in expanding human cord blood (CB) CD34 + hematopoietic stem/progenitor cells. MLL-AF9-transduced CB CD34 + cells could be transformed efficiently along myeloid or lymphoid lineages on IL-3- and TPO-producing MSCs. In vivo, these genetically engineered MSCs maintained their ability to differentiate into bone, adipocytes, and other stromal components. Upon transplantation of MLL-AF9-transduced CB CD34 + cells, acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) developed in engineered scaffolds, in which a significantly higher percentage of myeloid clones was observed in the mouse compartments compared with previous models. Engraftment of primary AML, B-cell ALL, and biphenotypic acute leukemia (BAL) patient samples was also evaluated, and all patient samples could engraft efficiently; the myeloid compartment of the BAL samples was better preserved in the human cytokine scaffold model. In conclusion, we show that we can genetically engineer the ectopic human BM microenvironment in a humanized scaffold xenograft model. This approach will be useful for functional study of the importance of niche factors in normal and malignant human hematopoiesis. Copyright © 2017 ISEH - International Society for Experimental Hematology. All rights reserved.

Relatively well preserved DNA is present in the crystal aggregates of fossil bones

PubMed Central

Salamon, Michal; Tuross, Noreen; Arensburg, Baruch; Weiner, Steve

2005-01-01

DNA from fossil human bones could provide invaluable information about population migrations, genetic relations between different groups and the spread of diseases. The use of ancient DNA from bones to study the genetics of past populations is, however, very often compromised by the altered and degraded state of preservation of the extracted material. The universally observed postmortem degradation, together with the real possibility of contamination with modern human DNA, makes the acquisition of reliable data, from humans in particular, very difficult. We demonstrate that relatively well preserved DNA is occluded within clusters of intergrown bone crystals that are resistant to disaggregation by the strong oxidant NaOCl. We obtained reproducible authentic sequences from both modern and ancient animal bones, including humans, from DNA extracts of crystal aggregates. The treatment with NaOCl also minimizes the possibility of modern DNA contamination. We thus demonstrate the presence of a privileged niche within fossil bone, which contains DNA in a better state of preservation than the DNA present in the total bone. This counterintuitive approach to extracting relatively well preserved DNA from bones significantly improves the chances of obtaining authentic ancient DNA sequences, especially from human bones. PMID:16162675

Is the corticomedullary index valid to distinguish human from nonhuman bones: a multislice computed tomography study.

PubMed

Rérolle, Camille; Saint-Martin, Pauline; Dedouit, Fabrice; Rousseau, Hervé; Telmon, Norbert

2013-09-10

The first step in the identification process of bone remains is to determine whether they are of human or nonhuman origin. This issue may arise when only a fragment of bone is available, as the species of origin is usually easily determined on a complete bone. The present study aims to assess the validity of a morphometric method used by French forensic anthropologists to determine the species of origin: the corticomedullary index (CMI), defined by the ratio of the diameter of the medullary cavity to the total diameter of the bone. We studied the constancy of the CMI from measurements made on computed tomography images (CT scans) of different human bones, and compared our measurements with reference values selected in the literature. The measurements obtained on CT scans at three different sites of 30 human femurs, 24 tibias, and 24 fibulas were compared between themselves and with the CMI reference values for humans, pigs, dogs and sheep. Our results differed significantly from these reference values, with three exceptions: the proximal quarter of the femur and mid-fibular measurements for the human CMI, and the proximal quarter of the tibia for the sheep CMI. Mid-tibial, mid-femoral, and mid-fibular measurements also differed significantly between themselves. Only 22.6% of CT scans of human bones were correctly identified as human. We concluded that the CMI is not an effective method for determining the human origin of bone remains. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Glycation Contributes to Interaction Between Human Bone Alkaline Phosphatase and Collagen Type I.

PubMed

Halling Linder, Cecilia; Enander, Karin; Magnusson, Per

2016-03-01

Bone is a biological composite material comprised primarily of collagen type I and mineral crystals of calcium and phosphate in the form of hydroxyapatite (HA), which together provide its mechanical properties. Bone alkaline phosphatase (ALP), produced by osteoblasts, plays a pivotal role in the mineralization process. Affinity contacts between collagen, mainly type II, and the crown domain of various ALP isozymes were reported in a few in vitro studies in the 1980s and 1990s, but have not attracted much attention since, although such interactions may have important implications for the bone mineralization process. The objective of this study was to investigate the binding properties of human collagen type I to human bone ALP, including the two bone ALP isoforms B1 and B2. ALP from human liver, human placenta and E. coli were also studied. A surface plasmon resonance-based analysis, supported by electrophoresis and blotting, showed that bone ALP binds stronger to collagen type I in comparison with ALPs expressed in non-mineralizing tissues. Further, the B2 isoform binds significantly stronger to collagen type I in comparison with the B1 isoform. Human bone and liver ALP (with identical amino acid composition) displayed pronounced differences in binding, revealing that post-translational glycosylation properties govern these interactions to a large extent. In conclusion, this study presents the first evidence that glycosylation differences in human ALPs are of crucial importance for protein-protein interactions with collagen type I, although the presence of the ALP crown domain may also be necessary. Different binding affinities among the bone ALP isoforms may influence the mineral-collagen interface, mineralization kinetics, and degree of bone matrix mineralization, which are important factors determining the material properties of bone.

Potential use of mesenchymal stem cells in human meniscal repair: current insights

PubMed Central

Pak, Jaewoo; Lee, Jung Hun; Park, Kwang Seung; Jeon, Jeong Ho; Lee, Sang Hee

2017-01-01

The menisci of the human knee play an important role in maintaining normal functions to provide stability and nutrition to the articular cartilage, and to absorb shock. Once injured, these important structures have very limited natural healing potential. Unfortunately, the traditional arthroscopic meniscectomy performed on these damaged menisci may predispose the joint toward early development of osteoarthritis. Although a very limited number of studies are available, mesenchymal stem cells (MSCs) have been investigated as an alternative therapeutic modality to repair human knee meniscal tears. This review summarizes the results of published applications of MSCs in human patients, which showed that the patients who received MSCs (autologous adipose tissue-derived stem cells or culture-expanded bone marrow-derived stem cells) presented symptomatic improvements, along with magnetic resonance imaging evidences of the meniscal repair. PMID:28356779

Contemporary biological markers of exposure to fluoride.

PubMed

Rugg-Gunn, Andrew John; Villa, Alberto Enrique; Buzalaf, Marília Rabelo Afonso

2011-01-01

Contemporary biological markers assess present, or very recent, exposure to fluoride: fluoride concentrations in blood, bone surface, saliva, milk, sweat and urine have been considered. A number of studies relating fluoride concentration in plasma to fluoride dose have been published, but at present there are insufficient data on plasma fluoride concentrations across various age groups to determine the 'usual' concentrations. Although bone contains 99% of the body burden of fluoride, attention has focused on the bone surface as a potential marker of contemporary fluoride exposure. From rather limited data, the ratio surface-to-interior concentration of fluoride may be preferred to whole bone fluoride concentration. Fluoride concentrations in the parotid and submandibular/sublingual ductal saliva follow the plasma fluoride concentration, although at a lower concentration. At present, there are insufficient data to establish a normal range of fluoride concentrations in ductal saliva as a basis for recommending saliva as a marker of fluoride exposure. Sweat and human milk are unsuitable as markers of fluoride exposure. A proportion of ingested fluoride is excreted in urine. Plots of daily urinary fluoride excretion against total daily fluoride intake suggest that daily urinary fluoride excretion is suitable for predicting fluoride intake for groups of people, but not for individuals. While fluoride concentrations in plasma, saliva and urine have some ability to predict fluoride exposure, present data are insufficient to recommend utilizing fluoride concentrations in these body fluids as biomarkers of contemporary fluoride exposure for individuals. Daily fluoride excretion in urine can be considered a useful biomarker of contemporary fluoride exposure for groups of people, and normal values have been published. Copyright © 2011 S. Karger AG, Basel.

Forward genetics defines Xylt1 as a key, conserved regulator of early chondrocyte maturation and skeletal length.

PubMed

Mis, Emily K; Liem, Karel F; Kong, Yong; Schwartz, Nancy B; Domowicz, Miriam; Weatherbee, Scott D

2014-01-01

The long bones of the vertebrate body are built by the initial formation of a cartilage template that is later replaced by mineralized bone. The proliferation and maturation of the skeletal precursor cells (chondrocytes) within the cartilage template and their replacement by bone is a highly coordinated process which, if misregulated, can lead to a number of defects including dwarfism and other skeletal deformities. This is exemplified by the fact that abnormal bone development is one of the most common types of human birth defects. Yet, many of the factors that initiate and regulate chondrocyte maturation are not known. We identified a recessive dwarf mouse mutant (pug) from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. pug mutant skeletal elements are patterned normally during development, but display a ~20% length reduction compared to wild-type embryos. We show that the pug mutation does not lead to changes in chondrocyte proliferation but instead promotes premature maturation and early ossification, which ultimately leads to disproportionate dwarfism. Using sequence capture and high-throughput sequencing, we identified a missense mutation in the Xylosyltransferase 1 (Xylt1) gene in pug mutants. Xylosyltransferases catalyze the initial step in glycosaminoglycan (GAG) chain addition to proteoglycan core proteins, and these modifications are essential for normal proteoglycan function. We show that the pug mutation disrupts Xylt1 activity and subcellular localization, leading to a reduction in GAG chains in pug mutants. The pug mutant serves as a novel model for mammalian dwarfism and identifies a key role for proteoglycan modification in the initiation of chondrocyte maturation. © 2013 Published by Elsevier Inc.

[Fractography of the long tubular bones of the lower extremities in trauma by blunt objects].

PubMed

Kriukov, V N; Bakhmet'ev, V I

1991-01-01

New data on micromorphological signs of fracture of long tubular bones in normal distribution and transformation of deforming forces are presented. Fractographic signs of bone for each destructive stage, signs of repeated trauma are singled out. Interrelationship between bone microstructure and conditions of its destruction is stated.

Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue☆

PubMed Central

Pemmer, B.; Roschger, A.; Wastl, A.; Hofstaetter, J.G.; Wobrauschek, P.; Simon, R.; Thaler, H.W.; Roschger, P.; Klaushofer, K.; Streli, C.

2013-01-01

Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radiation induced micro X-ray fluorescence analysis (SR μ-XRF) in combination with quantitative backscattered electron imaging (qBEI) to determine the distribution and accumulation of Zn, Sr, and Pb in human bone tissue. Fourteen human bone samples (10 femoral necks and 4 femoral heads) from individuals with osteoporotic femoral neck fractures as well as from healthy individuals were analyzed. Fluorescence intensity maps were matched with BE images and correlated with calcium (Ca) content. We found that Zn and Pb had significantly increased levels in the cement lines of all samples compared to the surrounding mineralized bone matrix. Pb and Sr levels were found to be correlated with the degree of mineralization. Interestingly, Zn intensities had no correlation with Ca levels. We have shown for the first time that there is a differential accumulation of the trace elements Zn, Pb and Sr in BSUs of human bone indicating different mechanisms of accumulation. PMID:23932972

Sphingosine 1-Phosphate (S1P) Receptors 1 and 2 Coordinately Induce Mesenchymal Cell Migration through S1P Activation of Complementary Kinase Pathways*

PubMed Central

Quint, Patrick; Ruan, Ming; Pederson, Larry; Kassem, Moustapha; Westendorf, Jennifer J.; Khosla, Sundeep; Oursler, Merry Jo

2013-01-01

Normal bone turnover requires tight coupling of bone resorption and bone formation to preserve bone quantity and structure. With aging and during several pathological conditions, this coupling breaks down, leading to either net bone loss or excess bone formation. To preserve or restore normal bone metabolism, it is crucial to determine the mechanisms by which osteoclasts and osteoblast precursors interact and contribute to coupling. We showed that osteoclasts produce the chemokine sphingosine 1-phosphate (S1P), which stimulates osteoblast migration. Thus, osteoclast-derived S1P may recruit osteoblasts to sites of bone resorption as an initial step in replacing lost bone. In this study we investigated the mechanisms by which S1P stimulates mesenchymal (skeletal) cell chemotaxis. S1P treatment of mesenchymal (skeletal) cells activated RhoA GTPase, but this small G protein did not contribute to migration. Rather, two S1P receptors, S1PR1 and S1PR2, coordinately promoted migration through activation of the JAK/STAT3 and FAK/PI3K/AKT signaling pathways, respectively. These data demonstrate that the chemokine S1P couples bone formation to bone resorption through activation of kinase signaling pathways. PMID:23300082

Ash content of bones in the pigtail monkey, Macaca nemestrina.

NASA Technical Reports Server (NTRS)

Vose, G. P.; Roach, T. L.

1972-01-01

Ash analyses of skeletons of four adult primates, Macaca nemestrina, revealed some similarities and some marked contrasts when compared with published data on human skeletal ash. The skull in both Macaca nemestrina and man has the highest ash content of all bones in the skeleton. While the bones of the arms of humans have an ash content nearly identical to that of the legs (0.3% difference), in Macaca nemestrina the humeri and radii contain 5.4% more ash than the femora and tibiae. Similarly in Macaca nemestrina the bones of the hands contain 3.5% more ash than the bones of the feet, while in humans the same bones agree within 0.3% implying that adaptive use function is a factor in bone ash concentration. The ribs of Macaca nemestrina showed an unexpectedly high ash content in comparison with those of humans. In contrast with the relatively constant ash content throughout the vertebrae in humans, a conspicuous decrease axially was noted in Macaca nemestrina.

Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis

DOE PAGES

Almeida-Porada, Graca; Rodman, Christopher; Kuhlman, Bradford; ...

2018-04-26

The stem cell compartment of the hematopoietic system constitutes one of the most radiosensitive tissues of the body and leukemias represent one of the most frequent radiogenic cancers with short latency periods. As such, leukemias may pose a particular threat to astronauts during prolonged space missions. Control of hematopoiesis is tightly governed by a specialized bone marrow (BM) microenvironment/niche. As such, any environmental insult that damages cells of this niche would be expected to produce pronounced effects on the types and functionality of hematopoietic/immune cells generated. We recently reported that direct exposure of human HSC to simulated SEP and GCRmore » radiation dramatically altered the differentiative potential of these cells, and that simulated GCR exposures can directly induce DNA damage and mutations within human HSC, which led to leukemic transformation when these cells repopulated murine recipients. In the present study, we performed the first in depth examination to define changes that occur in mesenchymal stem cells (MSC) present in the human BM niche following exposure to accelerated protons and iron ions, and assess the impact these changes have upon human hematopoiesis. Here, our data thus provides compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through so-called “biological bystander effects” by damaging the stromal cells that comprise the human marrow microenvironment, thereby altering their ability to support normal hematopoiesis.« less

Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almeida-Porada, Graca; Rodman, Christopher; Kuhlman, Bradford

The stem cell compartment of the hematopoietic system constitutes one of the most radiosensitive tissues of the body and leukemias represent one of the most frequent radiogenic cancers with short latency periods. As such, leukemias may pose a particular threat to astronauts during prolonged space missions. Control of hematopoiesis is tightly governed by a specialized bone marrow (BM) microenvironment/niche. As such, any environmental insult that damages cells of this niche would be expected to produce pronounced effects on the types and functionality of hematopoietic/immune cells generated. We recently reported that direct exposure of human HSC to simulated SEP and GCRmore » radiation dramatically altered the differentiative potential of these cells, and that simulated GCR exposures can directly induce DNA damage and mutations within human HSC, which led to leukemic transformation when these cells repopulated murine recipients. In the present study, we performed the first in depth examination to define changes that occur in mesenchymal stem cells (MSC) present in the human BM niche following exposure to accelerated protons and iron ions, and assess the impact these changes have upon human hematopoiesis. Here, our data thus provides compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through so-called “biological bystander effects” by damaging the stromal cells that comprise the human marrow microenvironment, thereby altering their ability to support normal hematopoiesis.« less

Exposure of the Bone Marrow Microenvironment to Simulated Solar and Galactic Cosmic Radiation Induces Biological Bystander Effects on Human Hematopoiesis.

PubMed

Almeida-Porada, Graça; Rodman, Christopher; Kuhlman, Bradford; Brudvik, Egil; Moon, John; George, Sunil; Guida, Peter; Sajuthi, Satria P; Langefeld, Carl D; Walker, Stephen J; Wilson, Paul F; Porada, Christopher D

2018-04-26

The stem cell compartment of the hematopoietic system constitutes one of the most radiosensitive tissues of the body and leukemias represent one of the most frequent radiogenic cancers with short latency periods. As such, leukemias may pose a particular threat to astronauts during prolonged space missions. Control of hematopoiesis is tightly governed by a specialized bone marrow (BM) microenvironment/niche. As such, any environmental insult that damages cells of this niche would be expected to produce pronounced effects on the types and functionality of hematopoietic/immune cells generated. We recently reported that direct exposure of human hematopoietic stem cells (HSC) to simulated solar energetic particle (SEP) and galactic cosmic ray (GCR) radiation dramatically altered the differentiative potential of these cells, and that simulated GCR exposures can directly induce DNA damage and mutations within human HSC, which led to leukemic transformation when these cells repopulated murine recipients. In this study, we performed the first in-depth examination to define changes that occur in mesenchymal stem cells present in the human BM niche following exposure to accelerated protons and iron ions and assess the impact these changes have upon human hematopoiesis. Our data provide compelling evidence that simulated SEP/GCR exposures can also contribute to defective hematopoiesis/immunity through so-called "biological bystander effects" by damaging the stromal cells that comprise the human marrow microenvironment, thereby altering their ability to support normal hematopoiesis.

Regenerative Stem Cell Therapy for Breast Cancer Bone Metastasis

DTIC Science & Technology

2014-09-01

13. SUPPLEMENTARY NOTES 14. ABSTRACT Bone is the most common site of metastasis for human breast cancer (BCa), which results in significant...to all major bones as in human patients. 15. SUBJECT TERMS Bone metastasis; osteolysis; osteoprotegerin 16. SECURITY CLASSIFICATION OF: 17...metastasis for human breast cancer (BCa), which results in significant morbidity and mortality in patients with advanced disease. A vicious cycle

Bone histomorphometry in de novo renal transplant recipients indicates a further decline in bone resorption 1 year posttransplantation.

PubMed

Evenepoel, Pieter; Behets, Geert J; Viaene, Liesbeth; D'Haese, Patrick C

2017-02-01

Renal transplantation is believed to have a major impact on bone health. The present prospective observational bone biopsy study aimed to define the natural history of bone histomorphometry parameters in contemporaneous de novo renal transplant recipients. Paired bone biopsies were performed at the time of transplantation and at one-year posttransplantation in an unselected cohort of 36 patients referred for deceased kidney replacement. Parameters of mineral metabolism and circulating bone turnover markers were monitored as well. Static parameters of bone formation and especially bone resorption being already low-normal in the majority of patients at the time of renal transplantation, further declined during the first posttransplant year. However, interindividual variation was substantial, and significance was reached only for bone resorption parameters. Bone mineralization and trabecular bone volume were within the normal range at the time of transplantation (83.3% and 91.7% of graft recipients, respectively) and showed little change one-year posttransplantation. Changes in osteoclast number were paralleled by changes in circulating tartrate-resistant acid phosphatase 5b levels. Finally, cumulative glucocorticoid dose, but not the posttransplantation parathyroid hormone level, associated with trabecular bone loss. Thus, the impact of renal transplantation on bone histomorphometry is limited with only bone resorption, being already low at the time of transplantation, showing a further decline. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Increased concentrations of bone sialoprotein in joint fluid after knee injury.

PubMed Central

Lohmander, L S; Saxne, T; Heinegård, D

1996-01-01

OBJECTIVE: To detect evidence for localised changes in bone matrix metabolism after joint trauma and in post-traumatic osteoarthritis by quantification of bone sialoprotein in joint fluid and serum after knee injury in a cross sectional study. METHODS: Samples of knee joint fluid and serum were obtained from volunteers with normal knees (n = 19), patients with rupture of the anterior cruciate ligament isolated or combined with tear of a meniscus (n = 114), and patients with isolated meniscus lesions (n = 80). Concentrations of bone sialoprotein were determined by ELISA. Concentrations of other markers of joint tissue metabolism in these samples were determined in previous investigations. RESULTS: The median concentrations of bone sialoprotein in joint fluid from healthy volunteers was 122 ng ml-1 (range 41 to 183). Concentrations of bone sialoprotein were increased in both injury groups compared with the reference group (median for cruciate ligament injury 146 ng ml-1, range 72 to 339; median for meniscus injury 166 ng ml-1, range 75 to 376). After injury, bone sialoprotein increased quickly and remained increased for six months. Bone sialoprotein in joint fluid was increased only in samples from joints with normal or nearly normal (fibrillated) cartilage, and was within reference range in joints with radiographic signs of osteoarthritis. Bone sialoprotein concentrations in joints with cruciate ligament injury were positively correlated with levels of aggrecan and cartilage oligomeric matrix protein fragments, and with levels of stromelysin-1 and tissue inhibitor of metalloproteinase-1. The ratios between the concentrations of bone sialoprotein in joint fluid and serum were > 1 in the majority of the cruciate ligament injury cases. CONCLUSIONS: The release of significant amounts of bone sialoprotein into joint fluid in connection with acute joint trauma may be associated with injury to, and active remodelling of, the cartilage-bone interface and subchondral bone. The findings are consistent with dramatic shifts in cartilage, bone, and synovial metabolism following joint injury. Bone sialoprotein concentrations in synovial fluid may be a useful marker of subchondral injury and remodelling following joint injury. PMID:8882132

A novel explanation of corneal clouding in a bone marrow transplant-treated patient with Hurler syndrome

PubMed Central

Yuan, Ching; Bothun, Erick D.; Hardten, David R.; Tolar, Jakub; McLoon, Linda K.

2016-01-01

One common complication of mucopolysaccharidosis I-Hurler (MPS1-H) is corneal clouding, which occurs despite current treatments, including bone marrow transplantation. Human corneas were obtained from a 14 year old subject with MPS1-H and visual disability from progressive corneal clouding despite a prior bone marrow transplant at age 2. This was compared to a cornea from a 17 year old donated to our eye bank after his accidental death. The corneas were analyzed microscopically after staining with Alcian blue, antibodies to collagen I, IV, VI, and α-smooth muscle actin. Differences in levels of expression of the indicated molecules were assessed. Corneas from Hurler and control mice were examined similarly to determine potential mechanistic overlap. The MPS1-H subject cornea showed elevations in mucopolysaccharide deposition. The MPS1-H and Hurler mice corneas showed increased and disorganized expression of collagen I and IV relative to the control corneas. The MPS1-H corneas also showed increased and disordered expression of collagen VI. Positive expression of α-smooth muscle actin indicated myofibroblast conversion within the MPS1-H cornea in both the patient and mutant mouse material compared to normal human and control mouse cornea. Increased deposition of collagens and smooth muscle actin correlate with corneal clouding, providing a potential mechanism for corneal clouding despite bone marrow transplantation in MPS1-H patients. It might be possible to prevent or slow the onset of corneal clouding by treating the cornea with drugs known to prevent myofibroblast conversion. PMID:27235795

Mice with cancer-induced bone pain show a marked decline in day/night activity

PubMed Central

Majuta, Lisa A.; Guedon, Jean-Marc G.; Mitchell, Stefanie A.T.; Kuskowski, Michael A.; Mantyh, Patrick W.

2017-01-01

Abstract Introduction: Cancer-induced bone pain (CIBP) is the most common type of pain with cancer. In humans, this pain can be difficult to control and highly disabling. A major problem with CIBP in humans is that it increases on weight-bearing and/or movement of a tumor-bearing bone limiting the activity and functional status of the patient. Currently, there is less data concerning whether similar negative changes in activity occur in rodent models of CIBP. Objectives: To determine whether there are marked changes in activity in a rodent model of CIBP and compare this to changes in skin hypersensitivity. Methods: Osteosarcoma cells were injected and confined to 1 femur of the adult male mouse. Every 7 days, spontaneous horizontal and vertical activities were assessed over a 20-hour day and night period using automated activity boxes. Mechanical hypersensitivity of the hind paw skin was assessed using von Frey testing. Results: As the tumor cells grew within the femur, there was a significant decline in horizontal and vertical activity during the times of the day/night when the mice are normally most active. Mice also developed significant hypersensitivity in the skin of the hind paw in the tumor-bearing limb. Conclusion: Even when the tumor is confined to a single load-bearing bone, CIBP drives a significant loss of activity, which increases with disease progression. Understanding the mechanisms that drive this reduction in activity may allow the development of therapies that allow CIBP patients to better maintain their activity and functional status. PMID:29392229

Inhibition of fatty acid biosynthesis prevents adipocyte lipotoxicity on human osteoblasts in vitro

PubMed Central

Elbaz, Alexandre; Wu, Xiying; Rivas, Daniel; Gimble, Jeffrey M; Duque, Gustavo

2010-01-01

Abstract Although increased bone marrow fat in age-related bone loss has been associated with lower trabecular mass, the underlying mechanism responsible remains unknown. We hypothesized that marrow adipocytes exert a lipotoxic effect on osteoblast function and survival through the reversible biosynthesis of fatty acids (FA) into the bone marrow microenvironment. We have used a two-chamber system to co-culture normal human osteoblasts (NHOst) with differentiating pre-adipocytes in the absence or presence of an inhibitor of FA synthase (cerulenin) and separated by an insert that allowed unidirectional trafficking of soluble factors only and prevented direct cell–cell contact. Supernatants were assayed for the presence of FA using mass spectophotometry. After 3 weeks in co-culture, NHOst showed significantly lower levels of differentiation and function based on lower mineralization and expression of alkaline phosphatase, osterix, osteocalcin and Runx2. In addition, NHOst survival was affected by the presence of adipocytes as determined by MTS-formazan and TUNEL assays as well as higher activation of caspases 3/7. These toxic effects were inhibited by addition of cerulenin. Furthermore, culture of NHOst with either adipocyte-conditioned media alone in the absence of adipocytes themselves or with the addition of the most predominant FA (stearate or palmitate) produced similar toxic results. Finally, Runx2 nuclear binding was affected by addition of either adipocyte conditioned media or FA into the osteogenic media. We conclude that the presence of FA within the marrow milieu can contribute to the age-related changes in bone mass and can be prevented by the inhibition of FA synthase. PMID:19382912

Osseous regeneration in the rat calvarium using novel delivery systems for recombinant human bone morphogenetic protein-2 (rhBMP-2).

PubMed

Kenley, R; Marden, L; Turek, T; Jin, L; Ron, E; Hollinger, J O

1994-10-01

In the current investigation, we report osseous regeneration in critical-size rat calvarial defects using recombinant human bone morphogenetic protein-2 (rhBMP-2) and novel delivery systems based on biomaterials. The novel systems combine rhBMP-2 with dry powder microparticles of poly(D,L-lactide-co-glycolide) (PLGA). The mixture of rhBMP-2 with PLGA microparticles is added to an aqueous solution of biopolymer to yield a semisolid paste. The biopolymers tested include autologous blood clot, hydroxypropyl methylcellulose, and sodium alginate cross-linked with calcium ion. Insoluble collageneous bone matrix was also studied as a control. Test articles were made at 0-, 10-, and 30-micrograms doses of rhBMP-2 and imiplanted in 8-mm-diameter rat calvarial defects (which will not heal if left untreated). The animals were examined 21 days after implantation by radiography, radiomorphometry, histology, and histomorphometry. All tested materials containing rhBMP-2 restored radiopacity and normal contouring to the calvarial defects. Samples without added rhBMP-2 yielded only soft tissue within the defects. Histology showed restoration of inner and outer bone tables plus marrow constituents. The PLGA microparticles were significantly resorbed at the 21-day time point. Although small differences between delivery systems were evident at 0- and 10-micrograms rhBMP-2 doses, all test articles performed essentially equivalently at the 30-micrograms dose. Thus, novel delivery systems for rhBMP-2 offer the promise of combining the intrinsic bioactivity of the osteoinductive protein with pharmaceutically acceptable biomaterials.

VEGF serum concentrations in patients with long bone fractures: a comparison between impaired and normal fracture healing.

PubMed

Sarahrudi, Kambiz; Thomas, Anita; Braunsteiner, Tomas; Wolf, Harald; Vécsei, Vilmos; Aharinejad, Seyedhossein

2009-10-01

Vascular endothelial growth factor (VEGF) plays an important role in the bone repair process as a potent mediator of angiogenesis and it influences directly osteoblast differentiation. Inhibiting VEGF suppresses angiogenesis and callus mineralization in animals. However, no data exist so far on systemic expression of VEGF with regard to delayed or failed fracture healing in humans. One hundred fourteen patients with long bone fractures were included in the study. Serum samples were collected over a period of 6 months following a standardized time schedule. VEGF serum concentrations were measured. Patients were assigned to one of two groups according to their course of fracture healing. The first group contained 103 patients with physiological fracture healing. Eleven patients with delayed or nonunions formed the second group of the study. In addition, 33 healthy volunteers served as controls. An increase of VEGF serum concentration within the first 2 weeks after fracture in both groups with a following decrease within 6 months after trauma was observed. Serum VEGF concentrations in patients with impaired fracture healing were higher compared to the patients with physiological healing during the entire observation period. However, statistically significant differences were not observed at any time point between both groups. VEGF concentrations in both groups were significantly higher than those in controls. The present results show significantly elevated serum concentrations of VEGF in patients after fracture of long bones especially at the initial healing phase, indicating the importance of VEGF in the process of fracture healing in humans. (c) 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Postnatal temporal bone ontogeny in Pan, Gorilla, and Homo, and the implications for temporal bone ontogeny in Australopithecus afarensis.

PubMed

Terhune, Claire E; Kimbel, William H; Lockwood, Charles A

2013-08-01

Assessments of temporal bone morphology have played an important role in taxonomic and phylogenetic evaluations of fossil taxa, and recent three-dimensional analyses of this region have supported the utility of the temporal bone for testing taxonomic and phylogenetic hypotheses. But while clinical analyses have examined aspects of temporal bone ontogeny in humans, the ontogeny of the temporal bone in non-human taxa is less well documented. This study examines ontogenetic allometry of the temporal bone in order to address several research questions related to the pattern and trajectory of temporal bone shape change during ontogeny in the African apes and humans. We further apply these data to a preliminary analysis of temporal bone ontogeny in Australopithecus afarensis. Three-dimensional landmarks were digitized on an ontogenetic series of specimens of Homo sapiens, Pan troglodytes, Pan paniscus, and Gorilla gorilla. Data were analyzed using geometric morphometric methods, and shape changes throughout ontogeny in relation to size were compared. Results of these analyses indicate that, despite broadly similar patterns, African apes and humans show marked differences in development of the mandibular fossa and tympanic portions of the temporal bone. These findings indicate divergent, rather than parallel, postnatal ontogenetic allometric trajectories for temporal bone shape in these taxa. The pattern of temporal bone shape change with size exhibited by A. afarensis showed some affinities to that of humans, but was most similar to extant African apes, particularly Gorilla. Copyright © 2013 Wiley Periodicals, Inc.

In vivo quantification of bone-fluorine by delayed neutron activation analysis: a pilot study of hand-bone-fluorine levels in a Canadian population.

PubMed

Chamberlain, Mike; Gräfe, James L; Aslam; Byun, Soo-Hyun; Chettle, David R; Egden, Lesley M; Webber, Colin E; McNeill, Fiona E

2012-03-01

Humans can be exposed to fluorine (F) through their diet, occupation, environment and oral dental care products. Fluorine, at proper dosages, is believed to have positive effects by reducing the incidence of dental caries, but fluorine toxicity can occur when people are exposed to excessive quantities of fluorine. In this paper we present the results of a small pilot in vivo study on 33 participants living in Southwestern Ontario, Canada. The mean age of participants was 45 ± 18 years with a range of 20-87 years. The observed calcium normalized hand-bone-fluorine concentrations in this small pilot study ranged from 1.1 to 8.8 mg F/g Ca. Every person measured in this study had levels of fluorine in bone above the detection limit of the system. The average fluorine concentration in bone was found to be 3.5 ± 0.4 mg F/g Ca. No difference was observed in average concentration for men and women. In addition, a significant correlation (r(2) = 0.55, p < 0.001) was observed between hand-bone-fluorine content and age. The amount of fluorine was found to increase at a rate of 0.084 ± 0.014 mg F/g Ca per year. There was no significant difference observed in this small group of subjects between the accumulation rates in men and women. To the best of our knowledge, this is the first time data from in vivo measurement of fluorine content in humans by neutron activation analysis have been presented. The data determined by this technique were found to be consistent with results from ex vivo studies from other countries. We suggest that the data demonstrate that this low risk non-invasive diagnostic technique will permit the routine assessment of bone-fluorine content with potential application in the study of clinical bone-related diseases. This small study demonstrated that people in Southern Ontario are exposed to fluoride in measureable quantities, and that fluoride can be seen to accumulate in bone with age. However, all volunteers were found to have levels below those expected with clinical fluorosis, and only one older subject was found to have levels comparable with preclinical exposure.

Human stem cell osteoblastogenesis mediated by novel glycogen synthase kinase 3 inhibitors induces bone formation and a unique bone turnover biomarker profile in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilmour, Peter S., E-mail: Peter.Gilmour@astrazeneca.com; O'Shea, Patrick J.; Fagura, Malbinder

Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging. GSK-3 inhibitorsmore » caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH{sub 1–34} or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption. - Highlights: • Wnt modulation with 3 novel GSK-3 inhibitors alters bone growth. • Human stem cell osteoblastogenesis and mineralisation produced by GSK-3 inhibition. • In rats, 3 GSK-3 inhibitors produced a unique serum bone turnover biomarker profile. • Enhanced bone formation was seen within 7 to 14 days of compound treatment in rats.« less

The impact of diabetes and diabetes medications on bone health.

PubMed

Gilbert, Matthew P; Pratley, Richard E

2015-04-01

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fragility fractures despite increased body weight and normal or higher bone mineral density. The mechanisms by which T2DM increases skeletal fragility are unclear. It is likely that a combination of factors, including a greater risk of falling, regional osteopenia, and impaired bone quality, contributes to the increased fracture risk. Drugs for the treatment of T2DM may also impact on the risk for fractures. For example, thiazolidinediones accelerate bone loss and increase the risk of fractures, particularly in older women. In contrast, metformin and sulfonylureas do not appear to have a negative effect on bone health and may, in fact, protect against fragility fracture. Animal models indicate a potential role for incretin hormones in bone metabolism, but there are only limited data on the impact of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 agonists on bone health in humans. Animal models also have demonstrated a role for amylin in bone metabolism, but clinical trials in patients with type 1 diabetes with an amylin analog (pramlintide) have not shown a significant impact on bone metabolism. The effects of insulin treatment on fracture risk are inconsistent with some studies showing an increased risk and others showing no effect. Finally, although there is limited information on the latest class of medications for the treatment of T2DM, the sodium-glucose co-transporter-2 inhibitors, these drugs do not seem to increase fracture risk. Because diabetes is an increasingly common chronic condition that can affect patients for many decades, further research into the effects of agents for the treatment of T2DM on bone metabolism is warranted. In this review, the physiological mechanisms and clinical impact of diabetes treatments on bone health and fracture risk in patients with T2DM are described.

Enhanced osteoporotic bone regeneration by strontium-substituted calcium silicate bioactive ceramics.

PubMed

Lin, Kaili; Xia, Lunguo; Li, Haiyan; Jiang, Xinquan; Pan, Haobo; Xu, Yuanjin; Lu, William W; Zhang, Zhiyuan; Chang, Jiang

2013-12-01

The regeneration capacity of the osteoporotic bones is generally lower than that of the normal bones. Current methods of bone defect treatment for osteoporosis are not always satisfactory. Recent studies have shown that the silicate based biomaterials can stimulate osteogenesis and angiogenesis due to the silicon (Si) ions released from the materials, and enhance bone regeneration in vivo. Other studies showed that strontium (Sr) plays a distinct role on inhibiting bone resorption. Based on the hypothesis that the combination of Si and Sr may have synergetic effects on osteoporotic bone regeneration, the porous Sr-substituted calcium silicate (SrCS) ceramic scaffolds combining the functions of Sr and Si elements were developed with the goals to promote osteoporotic bone defect repair. The effects of the ionic extract from SrCS on osteogenic differentiation of bone marrow mesenchymal stem cells derived from ovariectomized rats (rBMSCs-OVX), angiogenic differentiation of human umbilical vein endothelial cells (HUVECs) were investigated. The in vitro results showed that Sr and Si ions released from SrCS enhanced cell viability, alkaline phosphatase (ALP) activity, and mRNA expression levels of osteoblast-related genes of rBMSCs-OVX and expression of vascular endothelial growth factor (VEGF) without addition of extra osteogenic and angiogenic reagents. The activation in extracellular signal-related kinases (ERK) and p38 signaling pathways were observed in rBMSCs-OVX cultured in the extract of SrCS, and these effects could be blocked by ERK inhibitor PD98059, and P38 inhibitor SB203580, respectively. Furthermore, the ionic extract of SrCS stimulated HUVECs proliferation, differentiation and angiogenesis process. The in vivo experiments revealed that SrCS dramatically stimulated bone regeneration and angiogenesis in a critical sized OVX calvarial defect model, and the enhanced bone regeneration might be attributed to the modulation of osteogenic differentiation of endogenous mesenchymal stem cells (MSCs) and the inhibition of osteoclastogenesis, accompanying with the promotion of the angiogenic activity of endothelial cells (ECs). Copyright © 2013 Elsevier Ltd. All rights reserved.

Gracility of the modern Homo sapiens skeleton is the result of decreased biomechanical loading.

PubMed

Ryan, Timothy M; Shaw, Colin N

2015-01-13

The postcranial skeleton of modern Homo sapiens is relatively gracile compared with other hominoids and earlier hominins. This gracility predisposes contemporary humans to osteoporosis and increased fracture risk. Explanations for this gracility include reduced levels of physical activity, the dissipation of load through enlarged joint surfaces, and selection for systemic physiological characteristics that differentiate modern humans from other primates. This study considered the skeletal remains of four behaviorally diverse recent human populations and a large sample of extant primates to assess variation in trabecular bone structure in the human hip joint. Proximal femur trabecular bone structure was quantified from microCT data for 229 individuals from 31 extant primate taxa and 59 individuals from four distinct archaeological human populations representing sedentary agriculturalists and mobile foragers. Analyses of mass-corrected trabecular bone variables reveal that the forager populations had significantly higher bone volume fraction, thicker trabeculae, and consequently lower relative bone surface area compared with the two agriculturalist groups. There were no significant differences between the agriculturalist and forager populations for trabecular spacing, number, or degree of anisotropy. These results reveal a correspondence between human behavior and bone structure in the proximal femur, indicating that more highly mobile human populations have trabecular bone structure similar to what would be expected for wild nonhuman primates of the same body mass. These results strongly emphasize the importance of physical activity and exercise for bone health and the attenuation of age-related bone loss.

TU-A-12A-08: Computing Longitudinal Material Changes in Bone Metastases Using Dual Energy Computed Tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidtlein, CR; Hwang, S; Veeraraghavan, H

Purpose: This study demonstrates a methodology for tracking changes in metastatic bone disease using trajectories in material basis space in serial dual energy computed tomography (DECT) studies. Methods: This study includes patients with bone metastases from breast cancer that had clinical surveillance CT scans using a General Electric CT750HD in dual energy mode. A radiologist defined regions-of-interested (ROI) for bone metastasis, normal bone, and marrow across the serial DECT scans. Our approach employs a Radon transform to forward-projection the basis images, namely, water and iodine, into sinogram space. This data is then repartitioned into fat/bone and effective density/Z image pairsmore » using assumed energy spectrums for the x-ray energies. This approach both helps remove negative material densities and avoids adding spectrum-hardening artifacts. These new basis data sets were then reconstructed via filtered back-projection to create new material basis pair images. The trajectories of these pairs were then plotted in the new basis space providing a means to both visualize and quantitatively measure changes in the material properties of the tumors. Results: ROI containing radiologist defined metastatic bone disease showed well-defined trajectories in both fat/bone and effective density/Z space. ROI that contained radiologist defined normal bone and marrow did not exhibit any discernible trajectories and were stable from scan to scan. Conclusions: The preliminary results show that changes in material composition and effective density/Z image pairs were seen primarily in metastasis and not in normal tissue. This study indicates that by using routine clinical DECT it may be possible to monitor therapy response of bone metastases because healing or worsening bone metastases change material composition of bone. Additional studies are needed to further validate these results and to test for their correlation with outcome.« less

Bone microstructure in men assessed by HR-pQCT: Associations with risk factors and differences between men with normal, low, and osteoporosis-range areal BMD.

PubMed

Okazaki, Narihiro; Burghardt, Andrew J; Chiba, Ko; Schafer, Anne L; Majumdar, Sharmila

2016-12-01

The primary objective of this study was to analyze the relationships between bone microstructure and strength, and male osteoporosis risk factors including age, body mass index, serum 25-hydroxyvitamin D level, and testosterone level. A secondary objective was to compare microstructural and strength parameters between men with normal, low, and osteoporosis-range areal bone mineral density (aBMD). Seventy-eight healthy male volunteers (mean age 62.4 ± 7.8 years, range 50-84 years) were recruited. The participants underwent dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT) of the ultra-distal radius and tibia. From the HR-pQCT images, volumetric bone mineral density (BMD) and cortical and trabecular bone microstructure were evaluated, and bone strength and cortical load fraction (Ct.LF) were estimated using micro-finite element analysis (μFEA). Age was more strongly correlated with bone microstructure than other risk factors. Age had significant positive correlations with cortical porosity at both ultra-distal radius and tibia ( r  = 0.36, p  = 0.001, and r  = 0.47, p  < 0.001, respectively). At the tibia, age was negatively correlated with cortical BMD, whereas it was positively correlated with trabecular BMD. In μFEA, age was negatively correlated with Ct.LF, although not with bone strength. Compared with men with normal aBMD, men with low or osteoporosis-range aBMD had significantly poor trabecular bone microstructure and lower bone strength at the both sites, while there was no significant difference in cortical bone. Cortical bone microstructure was negatively affected by aging, and there was a suggestion that the influence of aging may be particularly important at the weight-bearing sites.

Generation of a Bone Organ by Human Adipose-Derived Stromal Cells Through Endochondral Ossification.

PubMed

Osinga, Rik; Di Maggio, Nunzia; Todorov, Atanas; Allafi, Nima; Barbero, Andrea; Laurent, Frédéric; Schaefer, Dirk Johannes; Martin, Ivan; Scherberich, Arnaud

2016-08-01

: Recapitulation of endochondral ossification (ECO) (i.e., generation of marrow-containing ossicles through a cartilage intermediate) has relevance to develop human organotypic models for bone or hematopoietic cells and to engineer grafts for bone regeneration. Unlike bone marrow-derived stromal cells (also known as bone marrow-derived mesenchymal stromal/stem cells), adipose-derived stromal cells (ASC) have so far failed to form a bone organ by ECO. The goal of the present study was to assess whether priming human ASC to a defined stage of chondrogenesis in vitro allows their autonomous ECO upon ectopic implantation. ASC were cultured either as micromass pellets or into collagen sponges in chondrogenic medium containing transforming growth factor-β3 and bone morphogenetic protein-6 for 4 weeks (early hypertrophic templates) or for two additional weeks in medium supplemented with β-glycerophosphate, l-thyroxin, and interleukin1-β to induce hypertrophic maturation (late hypertrophic templates). Constructs were implanted in vivo and analyzed after 8 weeks. In vitro, ASC deposited cartilaginous matrix positive for glycosaminoglycans, type II collagen, and Indian hedgehog. Hypertrophic maturation induced upregulation of type X collagen, bone sialoprotein, and matrix metalloproteinase13 (MMP13). In vivo, both early and late hypertrophic templates underwent cartilage remodeling, as assessed by MMP13- and tartrate-resistant acid phosphatase-positive staining, and developed bone ossicles, including bone marrow elements, although to variable degrees of efficiency. In situ hybridization for human-specific sequences and staining with a human specific anti-CD146 antibody demonstrated the direct contribution of ASC to bone and stromal tissue formation. In conclusion, despite their debated skeletal progenitor nature, human ASC can generate bone organs through ECO when suitably primed in vitro. Recapitulation of endochondral ossification (ECO) (i.e., generation of marrow-containing ossicles through a cartilage intermediate) has relevance to develop human organotypic models for bone or hematopoietic cells and to engineer grafts for bone regeneration. This study demonstrated that expanded, human adult adipose-derived stromal cells can generate ectopic bone through ECO, as previously reported for bone marrow stromal cells. This system can be used as a model in a variety of settings for mimicking ECO during development, physiology, or pathology (e.g., to investigate the role of BMPs, their receptors, and signaling pathways). The findings have also translational relevance in the field of bone regeneration, which, despite several advances in the domains of materials and surgical techniques, still faces various limitations before being introduced in the routine clinical practice. ©AlphaMed Press.

Bone marrow adipocytes: a neglected target tissue for growth hormone.

PubMed

Gevers, Evelien F; Loveridge, Nigel; Robinson, Iain C A F

2002-10-01

Bone marrow (BM) contains numerous adipocytes. These share a common precursor with osteoblasts and chondrocytes, but their function is unknown. It is unclear what regulates the differentiation of these three different cell types, though their subsequent metabolic activity is under hormonal regulation. GH and estrogen stimulate bone growth and mineralization, by direct effects on chondrocytes and osteoblasts. GH also stimulates lipolysis in subcutaneous and visceral adipocytes. However, adipocytes in BM have largely been ignored as potential targets for GH or estrogen action. We have addressed this by measuring BM adipocyte number, perimeter and area as well as bone area and osteoblast activity in GH-deficient dwarf (dw/dw), normal, or ovariectomized (Ovx) rats, with or without GH, IGF-1, PTH, or estrogen treatment or high fat feeding. Marrow adipocyte numbers were increased 5-fold (P < 0.001) in dw/dw rats, and cell size was also increased by 20%. These values returned toward normal in dw/dw rats given GH but not when given IGF-1. Cancellous bone area and osteoblast number were significantly (P < 0.005) lower in dw/dw rats, though alkaline phosphatase (ALP) activity in individual osteoblasts was unchanged. GH treatment increased % osteoblast covered bone surface without affecting individual cell ALP activity. Ovariectomy in normal or dw/dw rats had no affect on marrow adipocyte number nor size, although estrogen treatment in ovariectomized (Ovx) normal rats did increase adipocyte number. Ovx decreased tibial cancellous bone area in normal rats (64%; P < 0.05) and decreased osteoblast ALP-activity (P < 0.01) but did not affect the percentage of osteoblast-covered bone surface. Estrogen replacement reversed these changes. While treatment with PTH by continuous sc infusion decreased cancellous bone (P < 0.05) and high fat feeding increased the size of BM adipocytes (P < 0.01), they did not affect BM adipocyte number. These results suggest that GH has a specific action on BM adipocytes that is not simply due to altered bone or fat metabolism. We conclude that the marrow adipocyte lineage is an important and specific target for GH action. The inverse relationship between adipocyte number and osteoblast covered bone surface, together with the well-known effects of GH on epiphysial chondrocytes leads us to propose that GH plays two important roles on cells of all three lineages. During differentiation, it regulates the numbers of each cell type that are maintained from the common precursor lineage. Subsequently it has cell-specific effects on the metabolic activities of the differentiated cells. In the case of marrow adipocytes, GH-dependent lipolysis could provide an important hormonally regulated local high energy source in bone.

Handling of induced hypercalcaemia in hyperthyroidism

PubMed Central

Lim, P.; Jacob, E.; Khoo, O. T.

1969-01-01

The mean serum calcium of 13 hyperthyroid patients was found to be significantly higher than that of controls matched for sex and age, though none of the patients' values were outside the normal range. Nevertheless, these patients responded very promptly to hypercalcaemia (induced by an intravenous calcium load), and their serum calcium returned to normal much more rapidly compared with the matched controls. There was also increased retention of intravenous calcium load, possibly owing to increased calcitonin production. Calcium infusion may be useful in treating bone diseases in which increased bone resorption exceeds bone accretion. PMID:5354875

Prediction of human gait parameters from temporal measures of foot-ground contact

NASA Technical Reports Server (NTRS)

Breit, G. A.; Whalen, R. T.

1997-01-01

Investigation of the influence of human physical activity on bone functional adaptation requires long-term histories of gait-related ground reaction force (GRF). Towards a simpler portable GRF measurement, we hypothesized that: 1) the reciprocal of foot-ground contact time (1/tc); or 2) the reciprocal of stride-period-normalized contact time (T/tc) predict peak vertical and horizontal GRF, loading rates, and horizontal speed during gait. GRF data were collected from 24 subjects while they walked and ran at a variety of speeds. Linear regression and ANCOVA determined the dependence of gait parameters on 1/tc and T/tc, and prediction SE. All parameters were significantly correlated to 1/tc and T/tc. The closest pooled relationship existed between peak running vertical GRF and T/tc (r2 = 0.896; SE = 3.6%) and improved with subject-specific regression (r2 = 0.970; SE = 2.2%). We conclude that temporal measures can predict force parameters of gait and may represent an alternative to direct GRF measurements for determining daily histories of habitual lower limb loading quantities necessary to quantify a bone remodeling stimulus.

[Microsurgical transplantation of bone tumors of uncertain prognosis in athymic nude mice].

PubMed

Duprez, A; Féry, A; Sommelet, J

1986-01-01

Eight cases of human bone or soft tissue tumours were transplanted to nude mice. After such transplants to nude mice which are immunologically deficient, the malignant tumors developed like benign tumours, but maintaining malignant cytological characteristics. The transplants of normal human tissues or of benign tumours decreased in size or remained stable. The technique allowed a change of an original diagnosis of osteosarcoma to a final diagnosis of chondrosarcoma. It made it possible to diagnose a benign osteoblastoma, the diagnosis of which was doubtful before the transplant between osteosarcoma and chondroblastoma. It was possible to diagnose the malignancy of a haemangiopericytoma of muscle. Two aggressive tumours--a non-ossifying fibroma and a giant-cell tumour--were rated as benign after transplantation. This technique also allowed a more precise diagnosis of the grade of one chondrosarcoma and one osteosarcoma. Finally, transplantation also made it possible to test the efficacy of chemotherapy. In a patient so treated, the extreme cell proliferation after transplantation to the nude mouse led to a change in the drugs administered.

Microgravity

NASA Image and Video Library

1998-01-01

Astronaut John Blaha replaces an exhausted media bag and filled waste bag with fresh bags to continue a bioreactor experiment aboard space station Mir in 1996. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. This image is from a video downlink. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

Normal Untreated Jurkat Cells

NASA Technical Reports Server (NTRS)

2004-01-01

Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. The objective of the research was to define a way to differentiate between effects due to microgravity and those due to possible stress from non-optimal spaceflight conditions. These Jurkat cells, a human acute T-cell leukemia was obtained to evaluate three types of potential experimental stressors: a) Temperature elevation; b) Serum starvation; and c) Centrifugal force. The data from previous spaceflight experiments showed that actin filaments and cell shape are significantly different for the control. These normal cells serve as the baseline for future spaceflight experiments.

NASA Bioreactor

NASA Technical Reports Server (NTRS)

1998-01-01

Astronaut John Blaha replaces an exhausted media bag and filled waste bag with fresh bags to continue a bioreactor experiment aboard space station Mir in 1996. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. This image is from a video downlink. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

The Effect of Naturally Occurring Chronic Kidney Disease on the Micro-Structural and Mechanical Properties of Bone

PubMed Central

Meltzer, Hagar; Milrad, Moran; Brenner, Ori; Atkins, Ayelet; Shahar, Ron

2014-01-01

Chronic kidney disease (CKD) is a growing public health concern worldwide, and is associated with marked increase of bone fragility. Previous studies assessing the effect of CKD on bone quality were based on biopsies from human patients or on laboratory animal models. Such studies provide information of limited relevance due to the small size of the samples (biopsies) or the non-physiologic CKD syndrome studied (rodent models with artificially induced CKD). Furthermore, the type, architecture, structure and biology of the bone of rodents are remarkably different from human bones; therefore similar clinicopathologic circumstances may affect their bones differently. We describe the effects of naturally occurring CKD with features resembling human CKD on the skeleton of cats, whose bone biology, structure and composition are remarkably similar to those of humans. We show that CKD causes significant increase of resorption cavity density compared with healthy controls, as well as significantly lower cortical mineral density, cortical cross-sectional area and cortical cross-sectional thickness. Young's modulus, yield stress, and ultimate stress of the cortical bone material were all significantly decreased in the skeleton of CKD cats. Cancellous bone was also affected, having significantly lower trabecular thickness and bone volume over total volume in CKD cats compared with controls. This study shows that naturally occurring CKD has deleterious effects on bone quality and strength. Since many similarities exist between human and feline CKD patients, including the clinicopathologic features of the syndrome and bone microarchitecture and biology, these results contribute to better understanding of bone abnormalities associated with CKD. PMID:25333360

Denosumab treatment of prostate cancer with bone metastases and increased urine N-telopeptide levels after therapy with intravenous bisphosphonates: results of a randomized phase II trial.

PubMed

Fizazi, Karim; Bosserman, Linda; Gao, Guozhi; Skacel, Tomas; Markus, Richard

2009-08-01

Patients with bone metastases have high rates of RANKL driven bone resorption and an increased risk of skeletal morbidity. Osteoclast mediated bone resorption can be assessed by measuring urine N-telopeptide and can be inhibited by denosumab, a fully human antibody against RANKL. Eligible patients (111) had bone metastases from prostate cancer, other solid tumors or multiple myeloma, 1 or more bone lesions and urine N-telopeptide greater than 50 nM bone collagen equivalents per mM creatinine (urine N-telopeptide greater than 50) despite the use of intravenous bisphosphonates. Patients were stratified by cancer type and screening urine N-telopeptide, and randomized to continue intravenous bisphosphonates every 4 weeks or receive 180 mg subcutaneous denosumab every 4 weeks or 180 mg every 12 weeks. The primary end point was the proportion of patients with urine N-telopeptide less than 50 at week 13. We report the efficacy results for the subset of patients with prostate cancer. Patients with prostate cancer represented 45% (50 of 111) of the study population. At week 13, 22 of 32 (69%) patients in the denosumab arms had urine N-telopeptide less than 50 vs 3 of 16 (19%) in the intravenous bisphosphonates cohort. At week 25, 22 of 32 (69%) denosumab treated patients continued to have urine N-telopeptide less than 50 vs 5 of 16 (31%) treated with intravenous bisphosphonates. Grade 4, asymptomatic, reversible hypophosphatemia, possibly related to denosumab, was reported in 1 patient. In patients with prostate cancer related bone metastases and increased urine N-telopeptide despite intravenous bisphosphonate treatment, denosumab normalized urine N-telopeptide levels more frequently than ongoing intravenous bisphosphonates.

Transcriptional profiling of human femoral mesenchymal stem cells in osteoporosis and its association with adipogenesis.

PubMed

Choi, Yong Jun; Song, Insun; Jin, Yilan; Jin, Hyun-Seok; Ji, Hyung Min; Jeong, Seon-Yong; Won, Ye-Yeon; Chung, Yoon-Sok

2017-10-20

Genetic alterations are major contributing factors in the development of osteoporosis. Osteoblasts and adipocytes share a common origin, mesenchymal stem cells (MSCs), and their genetic determinants might be important in the relationship between osteoporosis and obesity. In the present study, we aimed to isolate differentially expressed genes (DEGs) in osteoporosis and normal controls using human MSCs, and elucidate the common pathways and genes related to osteoporosis and adipogenesis. Human MSCs were obtained from the bone marrow of femurs from postmenopausal women during orthopedic surgeries. RNA sequencing (RNA-seq) was carried out using next-generation sequencing (NGS) technology. DEGs were identified using RNA-seq data. Ingenuity pathway analysis (IPA) was used to elucidate the common pathway related to osteoporosis and adipogenesis. Candidate genes for the common pathway were validated with other independent osteoporosis and obese subjects using RT-PCR (reverse transcription-polymerase chain reaction) analysis. Fifty-three DEGs were identified between postmenopausal osteoporosis patients and normal bone mineral density (BMD) controls. Most of the genetic changes were related to the differentiation of cells. The nuclear receptor subfamily 4 group A (NR4A) family was identified as possible common genes related to osteogenesis and adipogenesis. The expression level of the mRNA of NR4A1 was significantly higher in osteoporosis patients than in controls (p=0.018). The expression level of the mRNA of NR4A2 was significantly higher in obese patients than in controls (p=0.041). Some genetic changes in MSCs are involved in the pathophysiology of osteoporosis. The NR4A family might comprise common genes related to osteoporosis and obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

Physiology and toxicity of fluoride.

PubMed

Dhar, Vineet; Bhatnagar, Maheep

2009-01-01

Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralization of bone and teeth. At high levels it has been known to cause dental and skeletal fluorosis. There are suggested effects of very high levels of fluoride on various body organs and genetic material. The purpose of this paper is to review the various aspects of fluoride and its importance in human life.

EVALUATION OF CALCIUM 47 IN NORMAL MAN AND ITS USE IN THE EVALUATION OF BONE HEALING FOLLOWING RADIATION THERAPY IN METASTATIC DESEASE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brady, L.W.; Croll, M.N.; Stanton, L.

1962-02-01

It was concluded that radioactlve Ca/sup 47/ is an isotope suitable for the study of calcium metabolism in the body. It is easily traced by external counting technics. Local uptake measurements as well as ratios over various areas of the skeleton can be determined, thus yielding useful diagnostic information. It is a safe agent for use. It is possible to differentiate normal bone from areas of diseased bone using it. It is not useful for scintiscanning. It is grossly applicable in the evaluation of effects of radiation therapy to local metastatic lesions in bone. These observations support the fact thatmore » bone- seeking isotopes may well be useful as diagnostic agents for the evaluation of subradiographic metastases. (auth)« less

Role of Corticosteroids in Bone Loss During Space Flight

NASA Technical Reports Server (NTRS)

Wronski, Thomas J.; Halloran, Bernard P.; Miller, Scott C.

1998-01-01

The primary objective of this research project is to test the hypothesis that corticosteroids contribute to the adverse skeletal effects of space flight. To achieve this objective, serum corticosteroids, which are known to increase during space flight, must be maintained at normal physiologic levels in flight rats by a combination of adrenalectomy and corticosteroid supplementation via implanted hormone pellets. Bone analyses in these animals will then be compared to those of intact flight rats that, based on past experience, will undergo corticosteroid excess and bone loss during space flight. The results will reveal whether maintaining serum corticosteroids at physiologic levels in flight rats affects the skeletal abnormalities that normally develop during space flight. A positive response to this question would indicate that the bone loss and decreased bone formation associated with space flight are mediated, at least in part, by corticosteroid excess.

The skeletal consequences of thyrotoxicosis.

PubMed

Nicholls, Jonathan J; Brassill, Mary Jane; Williams, Graham R; Bassett, J H Duncan

2012-06-01

Euthyroid status is essential for normal skeletal development and the maintenance of adult bone structure and strength. Established thyrotoxicosis has long been recognised as a cause of high bone turnover osteoporosis and fracture but more recent studies have suggested that subclinical hyperthyroidism and long-term suppressive doses of thyroxine (T4) may also result in decreased bone mineral density (BMD) and an increased risk of fragility fracture, particularly in postmenopausal women. Furthermore, large population studies of euthyroid individuals have demonstrated that a hypothalamic-pituitary-thyroid axis set point at the upper end of the normal reference range is associated with reduced BMD and increased fracture susceptibility. Despite these findings, the cellular and molecular mechanisms of thyroid hormone action in bone remain controversial and incompletely understood. In this review, we discuss the role of thyroid hormones in bone and the skeletal consequences of hyperthyroidism.

T-bone plastique for treatment of brachy-turricephaly.

PubMed

Donauer, E; Bernardy, M; Neuenfeldt, D

1993-01-01

The "T-Bone Plastique", which is presented in this paper, allows a surgical correction even of extreme cases of brachy-turricephaly together with malformations of the occipital region in one operative session. Brachy-turricephaly is characterized by abnormal vertical height of the skull and a shortening of its anterior-posterior length, frequently combined with malformations of the occipital region. Resection of the prematurely closed coronal suture, bi-parietal trepanations with 90 degrees rotation and side-exchange of the parietal bone flaps, double transverse trepanation of the occipital bone and outward bending and shifting of the bone fragments enable a bony remodeling and normalization of the deformed skull. Using this operative technique in three children we achieved a significant improvement of the skull form with an aesthetically pleasing result, without any neurologic sequelae and with normal development of the children during follow-up.

Cancer Secretome May Influence BSP and DSP Expression in Human Salivary Gland Cells

PubMed Central

Hamilton, Samantha Lynn; Ferando, Blake; Eapen, Asha Sarah; Yu, Jennifer Chian; Joy, Anita Rose

2016-01-01

One of the biggest challenges in managing head and neck cancers, especially salivary gland cancers, is the identification of secreted biomarkers of the disease that can be evaluated noninvasively. A relevant source of enriched tumor markers could potentially be found in the tumor secretome. Although numerous studies have evaluated secretomes from various cancers, the influence of the cancer secretome derived from salivary gland cancers on the behavior of normal cells has not yet been elucidated. Our data indicate that secretome derived from salivary gland cancer cells can influence the expression of two potential biomarkers of oral cancer—namely, bone sialoprotein (BSP) and dentin sialoprotein (DSP)—in normal salivary gland cells. Using routine immunohistochemistry, immunofluorescence, and immunoblotting techniques, we demonstrate an enrichment of BSP and DSP in human salivary gland (HSG) cancer tissue, unique localizations of BSP and DSP in HSG cancer cells, and enriched expression of BSP and DSP in normal salivary gland cells exposed to a cancer secretome. The secretome domain of the cancer microenvironment could alter signaling cascades responsible for normal cell proliferation, migration, and invasion, thus enhancing cancer cell survival and the potential for cancer progression. The cancer secretome may be critical in maintaining and stimulating “cancer-ness,” thus potentially promoting specific hallmarks of metastasis. PMID:27881474