Synchrotron microtomography‐based osteohistology of Gansus yumenensis : new data on the evolution of uninterrupted bone deposition in basal birds

2021 ◽  
Author(s):  
Quentin T. Monfroy ◽  
Martin Kundrát ◽  
Jingmai K. O’Connor ◽  
You Hai‐Lu ◽  
Federica Marone ◽  
...  
Keyword(s):  
Bone Deposition ◽  
Synchrotron Microtomography

18F-sodium fluoride bone deposition quantitation with PET in Mice: Variation with age, sex, and circadian rhythm

2020 ◽  
Vol 59 (06) ◽  
pp. 428-437
Author(s):  
Viktoria Dorau-Rutke ◽  
Kai Huang ◽  
Mathias Lukas ◽  
Marc O. Schulze ◽  
Christian Rosner ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Sodium Fluoride ◽  
Bone Growth ◽  
Bone Volume ◽  
Sleep Phase ◽  
Median Percentage ◽  
Bone Uptake ◽  
Pooled Data ◽  
Uptake Studies ◽  
Bone Deposition

Abstract Aim The aim of this study was to establish a data base for normal 18F-sodium fluoride (18F-NaF) bone uptake as a function of age, sex and circadian rhythm in mice. Methods In 12 female (F) and 12 male (M) C57BL/6N mice PET images were acquired 90 min after intravenous injection of 20 MBq 18F-NaF for 30 minutes. Each mouse was imaged in follow-up studies at 1, 3, 6, 13 and 21 months of age. In order to assess for physiologic changes related to circadian rhythm, animals were imaged during light (sleep phase) as well as during night conditions (awake phase). Bone uptake is described as the median percentage of the injected activity (%IA) and in relation to bone volume (%IA/ml). Results A significant smaller bone volume was found in F (1.79 ml) compared to M (1.99 ml; p < 0.001). In sex-pooled data, highest bone uptake occurred at an age of 1 month (61.1 %IA, 44.5 %IA/ml) with a significant reduction (p < 0.001) at age 3 months (43.6 %IA, 23.6 %IA/ml), followed by an increase between 13 (47.3 %IA, 24.5 %IA/ml) and 21 months (52.2 %IA, 28.1 %IA/ml). F had a significantly higher total uptake (F 48.2 %IA, M 43.8 %IA; p = 0.026) as well as a higher uptake per ml bone tissue (F 27.0 %IA/ml; M 22.4 %IA/ml; p < 0.001). A significant impact of circadian rhythm was only found for F at ages of 3 and 6 months with a higher uptake during the sleep phase. Conclusion Circadian rhythm had a significant impact on uptake only in F of 3 and 6 months. Regarding sex, F showed generally higher uptake rates than M. The highest uptake values were observed during bone growth at age 1 month in both sexes, a second uptake peak occurred in elderly F. Designing future bone uptake studies with M, attention must be paid to age only, while in F circadian rhythm and age must be taken into account.

scholarly journals Nanoscale Strontium-Substituted Hydroxyapatite Pastes and Gels for Bone Tissue Regeneration

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1611
Author(s):  
Caroline J. Harrison ◽  
Paul V. Hatton ◽  
Piergiorgio Gentile ◽  
Cheryl A. Miller
Keyword(s):  
Bone Tissue ◽  
Tissue Regeneration ◽  
Culture Media ◽  
Full Range ◽  
Sol Gel ◽  
Tissue Growth ◽  
Bone Tissue Regeneration ◽  
Tissue Culture Media ◽  
Bone Deposition

Injectable nanoscale hydroxyapatite (nHA) systems are highly promising biomaterials to address clinical needs in bone tissue regeneration, due to their excellent biocompatibility, bioinspired nature, and ability to be delivered in a minimally invasive manner. Bulk strontium-substituted hydroxyapatite (SrHA) is reported to encourage bone tissue growth by stimulating bone deposition and reducing bone resorption, but there are no detailed reports describing the preparation of a systematic substitution up to 100% at the nanoscale. The aim of this work was therefore to fabricate systematic series (0–100 atomic% Sr) of SrHA pastes and gels using two different rapid-mixing methodological approaches, wet precipitation and sol-gel. The full range of nanoscale SrHA materials were successfully prepared using both methods, with a measured substitution very close to the calculated amounts. As anticipated, the SrHA samples showed increased radiopacity, a beneficial property to aid in vivo or clinical monitoring of the material in situ over time. For indirect methods, the greatest cell viabilities were observed for the 100% substituted SrHA paste and gel, while direct viability results were most likely influenced by material disaggregation in the tissue culture media. It was concluded that nanoscale SrHAs were superior biomaterials for applications in bone surgery, due to increased radiopacity and improved biocompatibility.

scholarly journals Modified Spring for Uprighting Mesioangular Impacted Molars

2021 ◽  
pp. 030157422110180
Author(s):  
Prasanna Arvind Ravikumar ◽  
Navaneethan Ramasamy
Keyword(s):  
Nickel Titanium ◽  
Periodontal Status ◽  
Minimal Invasiveness ◽  
Distal Surface ◽  
Bone Deposition

Uprighting molar that is mesially angulated improves its periodontal status, coupled with bone deposition at the distal surface. 1 , 2 It also provides adequate support to its occlusal antagonist and maintains a stable occlusal pattern. Various methods for uprighting molars using springs, nickel-titanium superelastic wires, and miniscrews have been elucidated in literature. 3 - 5 This article presents a modification of spring fabricated of nickel-titanium that is effective in uprighting mesially angulated molars with minimal invasiveness. The proposed advantage of using this spring was that buccal flaring of the angulated molar was not observed due to the mild distalizing force applied against the molar by the tugging action of the spring.

scholarly journals Effects of low-dose aspirin on the osseointegration process in rats

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ana Carolina Lupepsa ◽  
Paula Vargas-Sanchez ◽  
Marcella Goetz Moro ◽  
Leomar Emanuel Almeida Mecca ◽  
Marcela Claudino ◽  
...  
Keyword(s):  
Low Dose ◽  
Inhibitory Effect ◽  
Control Group ◽  
Implant Placement ◽  
Dose Aspirin ◽  
Low Dose Aspirin ◽  
Male Wistar Rats ◽  
Bone To Implant Contact ◽  
Bone Deposition

Abstract Background Several drugs are capable of promoting changes in bone metabolism. The aim of this study was to evaluate the effect of long-term low-dose aspirin (LDA) therapy on implant osseointegration. Methods Male Wistar rats were divided into 4 groups (n = 8/group) according to oral gavage solution received prior (42 days) to the implant surgery on the tibia. The control group was treated with saline solution for 7 (CG-7) and 28 (CG-28) days. The use of low-dose aspirin was performed in AG groups (6.75 mg/kg of aspirin) for 7 (AG-7) and 28 (AG-28) days. After experimental periods, histomorphometric evaluation of bone-to-implant contact (BIC) and the bone area between threads (BABT) was performed. Results Reduced BIC values were detected in AG-7 (62.8% ± 17.1) group compared to AG-28 (91.9% ± 5.4), CG-7 (82.7% ± 15.2), and CG-28 (89.9% ± 9.7). BABT evaluation revealed lower values in AG-7 (70.9% ± 15.2) compared to AG-28 (95.4% ± 3.7) and CG-28 (87.1% ± 10.2) groups. Conclusions The treatment with low doses of aspirin promoted a discrete inhibitory effect in the early stages (7 days) of repair after implant placement, specifically in the bone deposition. However, these effects were not detected in the late stages (28 days), considering BIC and BABT parameters.

The Effect of Infection and Lag Screw Fixation on Revascularization and New Bone Deposition in Membranous Bone Grafts in a Rabbit Model

1996 ◽  
Vol 98 (2) ◽  
pp. 338-345 ◽  
Author(s):  
Jeffrey A. Fialkov ◽  
John H. Phillips ◽  
Sharon L. Walmsley ◽  
I. Morava-Protzner
Keyword(s):  
Screw Fixation ◽  
Rabbit Model ◽  
Bone Grafts ◽  
Lag Screw ◽  
Bone Deposition

Color changes in modern and fossil teeth induced by synchrotron microtomography

2012 ◽  
Vol 149 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Gary D. Richards ◽  
Rebecca S. Jabbour ◽  
Caroline F. Horton ◽  
Caitlin L. Ibarra ◽  
Alastair A. MacDowell
Keyword(s):  
Color Changes ◽  
Synchrotron Microtomography

scholarly journals Bmp7 and Lef1 Are the Downstream Effectors of Androgen Signaling in Androgen-Induced Sex Characteristics Development in Medaka

Endocrinology ◽  
2014 ◽  
Vol 155 (2) ◽  
pp. 449-462 ◽  
Author(s):  
Yukiko Ogino ◽  
Ikumi Hirakawa ◽  
Keiji Inohaya ◽  
Eri Sumiya ◽  
Shinichi Miyagawa ◽  
...  
Keyword(s):  
Reproductive Organs ◽  
Distal Region ◽  
Bmp Signaling ◽  
Sex Characteristics ◽  
Downstream Effectors ◽  
Androgen Exposure ◽  
Binding Factor ◽  
Bone Deposition ◽  
Characteristics Development ◽  
Secondary Sex Characters

Androgens play key roles in the morphological specification of male type sex attractive and reproductive organs, whereas little is known about the developmental mechanisms of such secondary sex characters. Medaka offers a clue about sexual differentiation. They show a prominent masculine sexual character for appendage development, the formation of papillary processes in the anal fin, which has been induced in females by exogenous androgen exposure. This current study shows that the development of papillary processes is promoted by androgen-dependent augmentation of bone morphogenic protein 7 (Bmp7) and lymphoid enhancer-binding factor-1 (Lef1). Androgen receptor (AR) subtypes, ARα and ARβ, are expressed in the distal region of outgrowing bone nodules of developing papillary processes. Development of papillary processes concomitant with the induction of Bmp7 and Lef1 in the distal bone nodules by exposure to methyltestosterone was significantly suppressed by an antiandrogen, flutamide, in female medaka. When Bmp signaling was inhibited in methyltestosterone-exposed females by its inhibitor, dorsomorphin, Lef1 expression was suppressed accompanied by reduced proliferation in the distal bone nodules and retarded bone deposition. These observations indicate that androgen-dependent expressions of Bmp7 and Lef1 are required for the bone nodule outgrowth leading to the formation of these secondary sex characteristics in medaka. The formation of androgen-induced papillary processes may provide insights into the mechanisms regulating the specification of sexual features in vertebrates.

A Single Low Dose of RGTA®, a New Healing Agent, Hastens Wound Maturation and Enhances Bone Deposition in Rat Craniotomy Defects

1999 ◽  
Vol 164 (3) ◽  
pp. 131-140 ◽  
Author(s):  
M.L. Colombier ◽  
J. Lafont ◽  
F. Blanquaert ◽  
J.P. Caruelle ◽  
D. Barritault ◽  
...  
Keyword(s):  
Low Dose ◽  
Healing Agent ◽  
Bone Deposition

Nanotechnology Enabled In Situ Orthopaedic Sensors for Personalized Medicine

2012 ◽  
Vol 86 ◽  
pp. 40-50
Author(s):  
Sirinrath Sirivisoot ◽  
Thomas J. Webster
Keyword(s):  
Bone Growth ◽  
Electrochemical Sensors ◽  
Electrochemical Analysis ◽  
Matrix Proteins ◽  
Implant Design ◽  
Implant Surface ◽  
Cellular Events ◽  
Bone Deposition ◽  
Made In

Although improvements have been made in implant design to increase bone formation and promote successful osseointegration using nanotechnology, the clinical diagnosis of early bone growth surrounding implants remains problematic. The development of a device allowing doctors to monitor the healing cascade and to diagnose potential infection or inflammation is necessary. Biological detection can be examined by the electrochemical analysis of electron transfer (or redox) reactions of extracellular matrix proteins involved in bone deposition and resorption. The use of nanomaterials as signal amplifiers in electrochemical sensors has greatly improved the sensitivity of detection. Nanotechnology-enabled electrochemical sensors that can be placed on the implant surface itself show promise as self-diagnosing devices in situ, possibly to detect new bone growth surrounding the implant and other cellular events to ensure implant success.

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