Age- And Genotype-dependence Of Bone Material Properties In The Osteogenesis Imperfecta Murine Model (oim)
(SAXS); calcified tissues; children; collagen; density; density distribution; electron-microscopy; Endocrinology & Metabolism; mechanical-properties; mice exhibit; microhardness; mineral; mineral crystals; murine model; osteogenesis imperfecta (OI); quantitative backscattered electron imaging (qBEI); small-angle X-ray scattering; tendon; x-ray-scattering
Cortical mineralization of long bones was studied in collagen alpha2(I)-deficient mice (oim) used as a model for human osteogenesis imperfecta. Aspects of the age development of the mice were characterized by combining nanometer- to micrometer-scale structural analysis with microhardness measurements. Bone structure was determined from homozygous (oini/oim) and heterozygous (oim/+) mice and their normal (+/+) littermates as a function of animal age by small-angle X-ray scattering (SAXS) and quantitative backscattered electron imaging (qBEI) measurements. SAXS studies found anomalies in the size and arrangement of bone mineral crystals in both homozygous and heterozygous mice aged 1-14 months. Generally, the crystals were smaller in thickness and less well aligned in these mice compared with control animals. An increase in the mean crystal thickness of the bone was found within all three genotypes up to an age of 3 months. Vicker's hardness measurements were significantly enhanced for oim bone (homozygotes and heterozygotes) compared with controls. The microhardness values were correlated directly with increased mineral content of homozygous and heterozygous compared with control bone, as determined by qBEI analysis. There was also a significant increase of mineral content with age. Two possibilities for collagen-mineral association are discussed for explaining the increased hardness and mineral content of oim/oim bone, together with its decreased toughness and thinner mineral crystals. As a consequence of the present measurements, one model for oim bone could incorporate small and densely packed mineral crystals. A second model for possible collagen-mineral association in oim material would consist of two families of mineral crystals, one being smaller and the other being much larger than the crystals found in normal mouse long bones. (C) 2001 by Elsevier
Grabner B; Landis W J; Roschger P; Rinnerthaler S; Peterlik H; Klaushofer K; Fratzl P
Bone
2001
2001-11
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/s8756-3282(01)00594-4" target="_blank" rel="noreferrer noopener">10.1016/s8756-3282(01)00594-4</a>
Cell Death By Autoschizis In Tramp Prostate Carcinoma Cells As A Result Of Treatment By Ascorbate: Menadione Combination
ascorbate; autoschizis; carcinoma cells; cell death; combined vitamin-c; cultured-mammalian-cells; electron-microscopy; induced oxidative stress; kills cancer-cells; Microscopy; Microscopy; nuclease; Pathology; prostate; ribonucleoproteins; scanning electron; sodium ascorbate; synergistic antitumor-activity; TRAMP; transgenic adenocarcinoma; ultrastructural aspects
Gilloteaux J; Jamison J M; Neal D R
Ultrastructural Pathology
2005
2005-05
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1080/01913120590951239" target="_blank" rel="noreferrer noopener">10.1080/01913120590951239</a>
Pinch-off syndrome: Case report and collective review of the literature
Surgery; electron-microscopy; system; hemodialysis; embolization; permanent subclavian catheters; port; rare complication; scanning; sign; spontaneous fracture; venous access devices
Pinch-off syndrome (POS) occurs when a long-term central venous catheter is compressed between the clavicle and the first rib. The compression can cause transient obstruction of the catheter and may result in a tear or even complete transsection and embolization of the catheter. POS may be preceded by a finding of "pinch-off sign" on chest X-ray (CXR) films in which the catheter is indented as it passes beneath the clavicle. We performed a collective review of the 109 cases of POS in the medical literature and report 3 new cases. On average, POS occurs 5.3 months after the insertion of the catheter but has ranged from immediately after insertion to 60 months later. If the subclavian vein is used for access, then an upright CXR should be obtained after the procedure and periodically thereafter to rule-out POS. Treatment of POS is removal of the catheter. If the tip of the catheter has embolized, it can usually be retrieved percutaneously with a transvenous snare. POS can be prevented by using the internal jugular vein for access rather than the subclavian vein.
Mirza B; Vanek V W; Kupensky D T
American Surgeon
2004
2004-07
Journal Article or Conference Abstract Publication
n/a