Micro-morphological properties of osteons reveal changes in cortical bone stability during aging, osteoporosis and bisphosphonate treatment in women

2013 ◽  
Author(s):  
Andreas Bernhard ◽  
Petar Milovanovic ◽  
Michael Hahn ◽  
Danijela Djonic ◽  
Matthias Krause ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Morphological Properties ◽  
Bisphosphonate Treatment

Micro-morphological properties of osteons reveal changes in cortical bone stability during aging, osteoporosis, and bisphosphonate treatment in women

2013 ◽  
Vol 24 (10) ◽  
pp. 2671-2680 ◽  
Author(s):  
A. Bernhard ◽  
P. Milovanovic ◽  
E. A. Zimmermann ◽  
M. Hahn ◽  
D. Djonic ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Morphological Properties ◽  
Bisphosphonate Treatment

scholarly journals Suppressed Bone Turnover by Long-Term Bisphosphonate Treatment Accumulates Microdamage but Maintains Intrinsic Material Properties in Cortical Bone of Dog Rib

2005 ◽  
Vol 20 (11) ◽  
pp. 2066-2073 ◽  
Author(s):  
Satoshi Komatsubara ◽  
Satoshi Mori ◽  
Tasuku Mashiba ◽  
Jilliang Li ◽  
Kiichi Nonaka ◽  
...  
Keyword(s):  
Bone Turnover ◽  
Cortical Bone ◽  
Material Properties ◽  
Bisphosphonate Treatment

scholarly journals Suppressed Bone Turnover by Long-Term Bisphosphonate Treatment Accumulates Microdamage but Maintains Intrinsic Material Properties in Cortical Bone of Dog Rib

2004 ◽  
Vol 19 (6) ◽  
pp. 999-1005 ◽  
Author(s):  
Satoshi Komatsubara ◽  
Satoshi Mori ◽  
Tasuku Mashiba ◽  
Jilliang Li ◽  
Kiichi Nonaka ◽  
...  
Keyword(s):  
Bone Turnover ◽  
Cortical Bone ◽  
Material Properties ◽  
Bisphosphonate Treatment

scholarly journals Reduced cortical bone compositional heterogeneity with bisphosphonate treatment in postmenopausal women with intertrochanteric and subtrochanteric fractures

2012 ◽  
Vol 27 (3) ◽  
pp. 672-678 ◽  
Author(s):  
Eve Donnelly ◽  
Dennis S Meredith ◽  
Joseph T Nguyen ◽  
Brian P Gladnick ◽  
Brian J Rebolledo ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Postmenopausal Women ◽  
Compositional Heterogeneity ◽  
Bisphosphonate Treatment ◽  
Subtrochanteric Fractures

scholarly journals Atypical fracture with long-term bisphosphonate therapy is associated with altered cortical composition and reduced fracture resistance

2017 ◽  
Vol 114 (33) ◽  
pp. 8722-8727 ◽  
Author(s):  
Ashley A. Lloyd ◽  
Bernd Gludovatz ◽  
Christoph Riedel ◽  
Emma A. Luengo ◽  
Rehan Saiyed ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Postmenopausal Women ◽  
Osteoporotic Fractures ◽  
Fracture Morphology ◽  
Fracture Repair ◽  
Initiation Toughness ◽  
Bisphosphonate Treatment ◽  
Toughening Mechanisms ◽  
Bone Biopsies

Bisphosphonates are the most widely prescribed pharmacologic treatment for osteoporosis and reduce fracture risk in postmenopausal women by up to 50%. However, in the past decade these drugs have been associated with atypical femoral fractures (AFFs), rare fractures with a transverse, brittle morphology. The unusual fracture morphology suggests that bisphosphonate treatment may impair toughening mechanisms in cortical bone. The objective of this study was to compare the compositional and mechanical properties of bone biopsies from bisphosphonate-treated patients with AFFs to those from patients with typical osteoporotic fractures with and without bisphosphonate treatment. Biopsies of proximal femoral cortical bone adjacent to the fracture site were obtained from postmenopausal women during fracture repair surgery (fracture groups, n = 33) or total hip arthroplasty (nonfracture groups, n = 17). Patients were allocated to five groups based on fracture morphology and history of bisphosphonate treatment [+BIS Atypical: n = 12, BIS duration: 8.2 (3.0) y; +BIS Typical: n = 10, 7.7 (5.0) y; +BIS Nonfx: n = 5, 6.4 (3.5) y; −BIS Typical: n = 11; −BIS Nonfx: n = 12]. Vibrational spectroscopy and nanoindentation showed that tissue from bisphosphonate-treated women with atypical fractures was harder and more mineralized than that from bisphosphonate-treated women with typical osteoporotic fractures. In addition, fracture mechanics measurements showed that tissue from patients treated with bisphosphonates had deficits in fracture toughness, with lower crack-initiation toughness and less crack deflection at osteonal boundaries than that of bisphosphonate-naïve patients. Together, these results suggest a deficit in intrinsic and extrinsic toughening mechanisms, which contribute to AFFs in patients treated with long-term bisphosphonates.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

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