scholarly journals Localized, time-dependent responses of rat cranial bone to repeated mild traumatic brain injuries

2021 ◽  
Author(s):  
Larissa K Dill ◽  
Natalie A Sims ◽  
Ali Shad ◽  
Chidozie Anyaegbu ◽  
Andrew Warnock ◽  
...  
Keyword(s):  
Brain Injuries ◽  
Bone Structure ◽  
Regions Of Interest ◽  
Cranial Bone ◽  
Micro Computed Tomography ◽  
Bone Thickness ◽  
Injury Site ◽  
Microstructural Alterations ◽  
Closed Head ◽  
Weight Drop

While it is well-established that bone responds dynamically to mechanical loading, the effects of mild traumatic brain injury (mTBI) on cranial bone composition are unclear. We hypothesized that repeated mTBI (rmTBI) would change the microstructure of cranial bones, without gross skull fractures. To address this, young adult female Piebald Viral Glaxo rats received sham, 1x, 2x or 3x closed-head mTBIs delivered at 24h intervals, using a weight drop device custom built for reproducible impact. Skull bones were collected at 2 or 10 weeks after the final injury/sham procedure, imaged by micro computed tomography and analyzed at predetermined regions of interest. In the interparietal bone, proximal to the injury site, modest increases in bone thickness was observed at 2 weeks, particularly following 3x mTBI. By 10 weeks, 2x mTBI induced a robust increase in the volume and thickness of the interparietal bone, alongside a corresponding decrease in the volume of marrow cavities in the diploe region. In contrast, neither parietal nor frontal skull samples were affected by rmTBI. Our findings demonstrate time- and location-dependent effects of rmTBI on cranial bone structure, highlighting a need to consider microstructural alterations to cranial bone when assessing the consequences of rmTBI.

scholarly journals DEVELOPING THE COMMON MARMOSET AS A TRANSLATIONAL MODEL OF AGE-RELATED OSTEOARTHRITIS

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S104-S104
Author(s):  
Dennis M Minton ◽  
Angela J Marolf ◽  
Kelly S Santangelo ◽  
Adam B Salmon ◽  
Adam R Konopka
Keyword(s):  
Subchondral Bone ◽  
Bone Structure ◽  
Common Marmoset ◽  
Knee Joints ◽  
Micro Computed Tomography ◽  
Bone Thickness ◽  
Aging Research ◽  
Naturally Occurring ◽  
Age Related ◽  
The Common

Abstract Age is a primary risk factor for osteoarthritis (OA). The mechanisms that contribute to OA are poorly understood and disease modifying treatments have not been identified. A critical shortcoming in developing therapies is the limited number of translational models available to identify the causes of naturally occurring OA. Our goal is to use the common marmoset as a non-human primate (NHP) model of age-related OA. NHP are the closest evolutionary relative to humans and share many characteristics of human aging. The marmoset has advantages over other NHP for aging research because of their relatively short maximal lifespan and small size. Micro-computed tomography (uCT) was performed on whole-knee joints obtained from young (10 yrs, n=3) marmosets at necropsy. OA was evaluated using a clinical uCT scoring system and quantitative assessments of subchondral bone structure and ossified meniscal volume. Advancing age was positively correlated to increased uCT OA score (p<0.05, r=0.59 ), mainly through increased number and size of osteophytes and progressive subchondral bone sclerosis from the medial to both medial and lateral compartments. For marmosets displaying meniscal ossification, older marmosets had greater (p<0.05) ossified meniscal volume than middle-aged and younger marmosets, respectively. Trabecular (p=0.05) and cortical bone thickness (p<0.05) were also lower in older marmosets. These data are the first to indicate that the marmoset develops naturally occurring, age-related OA and support the pursuit of additional studies using the marmoset to identify OA mechanisms and test potential interventions.

scholarly journals Topical co‐administration of zoledronate with recombinant human bone morphogenetic protein-2 can induce and maintain bone formation in the bone marrow environment

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hideki Ueyama ◽  
Yoichi Ohta ◽  
Yuuki Imai ◽  
Akinobu Suzuki ◽  
Ryo Sugama ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Formation ◽  
Bone Structure ◽  
Precursor Cells ◽  
The Other ◽  
Bone Morphogenetic Protein 2 ◽  
New Bone Formation ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Left Femur

Abstract Background Bone morphogenetic proteins (BMPs) induce osteogenesis in various environments. However, when BMPs are used alone in the bone marrow environment, the maintenance of new bone formation is difficult owing to vigorous bone resorption. This is because BMPs stimulate the differentiation of not only osteoblast precursor cells but also osteoclast precursor cells. The present study aimed to induce and maintain new bone formation using the topical co-administration of recombinant human BMP-2 (rh-BMP-2) and zoledronate (ZOL) on beta-tricalcium phosphate (β-TCP) composite. Methods β-TCP columns were impregnated with both rh-BMP-2 (30 µg) and ZOL (5 µg), rh-BMP-2 alone, or ZOL alone, and implanted into the left femur canal of New Zealand white rabbits (n = 56). The implanted β-TCP columns were harvested and evaluated at 3 and 6 weeks after implantation. These harvested β-TCP columns were evaluated radiologically using plane radiograph, and histologically using haematoxylin/eosin (H&E) and Masson’s trichrome (MT) staining. In addition, micro-computed tomography (CT) was performed for qualitative analysis of bone formation in each group (n = 7). Results Tissue sections stained with H&E and MT dyes revealed that new bone formation inside the β-TCP composite was significantly greater in those impregnated with both rh-BMP-2 and ZOL than in those from the other experimental groups at 3 and 6 weeks after implantations (p < 0.05). Micro-CT data also demonstrated that the bone volume and the bone mineral density inside the β-TCP columns were significantly greater in those impregnated with both rh-BMP-2 and ZOL than in those from the other experimental groups at 3 and 6 weeks after implantations (p < 0.05). Conclusions The topical co-administration of both rh-BMP-2 and ZOL on β-TCP composite promoted and maintained newly formed bone structure in the bone marrow environment.

scholarly journals A New Predictive Modality of Cranial Bone Thickness

1999 ◽  
Vol 42 (6) ◽  
pp. 651-657 ◽  
Author(s):  
Mohammed M. Elahi ◽  
Kenneth L. Watkin ◽  
M Suheil Hakim ◽  
Melvin D. Schloss ◽  
M Lucie Lessard
Keyword(s):  
Cranial Bone ◽  
Bone Thickness

scholarly journals Reducing radiation exposure in newborns with birth head trauma

2017 ◽  
Vol 5 (4) ◽  
pp. 24-30
Author(s):  
Irina A. Kriukova ◽  
Evgeniy Y. Kriukov ◽  
Danil A. Kozyrev ◽  
Semen A. Sotniкov ◽  
Dmitriy A. Iova ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Exposure ◽  
Head Trauma ◽  
Bone Structure ◽  
Bone Fractures ◽  
Diagnostic Methods ◽  
Cranial Bone ◽  
X Ray ◽  
Reduce Radiation Exposure ◽  
Risk Of Cancer

Background. Birth head trauma causing intracranial injury is one of the most common causes of neonatal mortality and morbidity. In case of suspected cranial fractures and intracranial hematomas, diagnostic methods involving radiation, such as x-ray radiography and computed tomography, are recommended. Recently, an increasing number of studies have highlighted the risk of cancer complications associated with computed tomography in infants. Therefore, diagnostic methods that reduce radiation exposure in neonates are important. One such method is ultrasonography (US). Aim. We evaluated US as a non-ionizing radiation method for diagnosis of cranial bone fractures and epidural hematomas in newborns with cephalohematomas or other birth head traumas. Material and methods. The study group included 449 newborns with the most common variant of birth head trauma: cephalohematomas. All newborns underwent transcranial-transfontanelle US for detection of intracranial changes and cranial US for visualization of bone structure in the cephalohematoma region. Children with ultrasonic signs of cranial fractures and epidural hematomas were further examined at a children’s hospital by x-ray radiography and/or computed tomography. Results and discussion. We found that cranial US for diagnosis of cranial fractures and transcranial-transfontanelle US for diagnosis of epidural hematomas in newborns were highly effective. In newborns with parietal cephalohematomas (444 children), 17 (3.8%) had US signs of linear fracture of the parietal bone, and 5 (1.1%) had signs of ipsilateral epidural hematoma. Epidural hematomas were visualized only when US was performed through the temporal bone and not by using the transfontanelle approach. Sixteen cases of linear fractures and all epidural hematomas were confirmed by computed tomography. Conclusion. The use of US diagnostic methods reduced radiation exposure in newborns with birth head trauma. US methods (transcranial-transfontanelle and cranial) can be used in screening for diagnosis and personalized monitoring of changes in birth head trauma as well as to reduce radiation exposure.

The Strain Rates of the Brain and Skull Under Dynamic Loading

2018 ◽  
Author(s):  
Mohammad Hosseini Farid ◽  
Ashkan Eslaminejad ◽  
Mohammadreza Ramzanpour ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Material Properties ◽  
Brain Injuries ◽  
Human Head ◽  
Element Model ◽  
Blast Waves ◽  
Cranial Bone ◽  
Strain Rates ◽  
Head Acceleration ◽  
Blunt Impact ◽  
The Brain

Accurate material properties of the brain and skull are needed to examine the biomechanics of head injury during highly dynamic loads such as blunt impact or blast. In this paper, a validated Finite Element Model (FEM) of a human head is used to study the biomechanics of the head in impact and blast leading to traumatic brain injuries (TBI). We simulate the head under various direction and velocity of impacts, as well as helmeted and un-helmeted head under blast waves. It is shown that the strain rates for the brain at impacts and blast scenarios are usually in the range of 36 to 241 s−1. The skull was found to experience a rate in the range of 14 to 182 s−1 under typical impact and blast cases. Results show for impact incidents the strain rates of brain and skull are approximately 1.9 and 0.7 times of the head acceleration. Also, this ratio of strain rate to head acceleration for the brain and skull was found to be 0.86 and 0.43 under blast loadings. These findings provide a good insight into measuring the brain tissue and cranial bone, and selecting material properties in advance for FEM of TBI.

scholarly journals Is the Jaw Bone Micro-Structure Altered in Response to Osteoporosis and Bisphosphonate Treatment? A Micro-CT Analysis

2021 ◽  
Vol 22 (12) ◽  
pp. 6559
Author(s):  
Marissa Chatterjee ◽  
Fernanda Faot ◽  
Cassia Correa ◽  
Jente Kerckhofs ◽  
Katleen Vandamme
Keyword(s):  
Negative Impact ◽  
Ex Vivo ◽  
Third Molar ◽  
Pairwise Comparison ◽  
Preventive Treatment ◽  
Regions Of Interest ◽  
Bisphosphonate Treatment ◽  
Micro Computed Tomography ◽  
Jaw Bone ◽  
Second Molar

The aim of the study was to quantify the micro-architectural changes of the jaw bone in response to ovariectomy, exposed or not to bisphosphonate treatment. A total of 47 Wistar rats were ovariectomized (OVX) or sham-operated (shOVX) and exposed to osteoporosis preventive treatment for eight weeks either with bisphosphonates (alendronate, ALN; group OVX-ALN) three days/week at a dose of 2 mg/kg or with saline solution (untreated control condition; group OVX). The bone morphometric parameters of the trabecular jaw bone were assessed using ex vivo micro-computed tomography. The regions of interest investigated in the maxilla were the inter-radicular septum of the second molar and the tuber. The regions quantified in the mandible included the three molar regions and the condyle. A one-way analysis of variance followed by pairwise comparison using Tukey’s HSD and the Games–Howell test was conducted to explore significant differences between the groups. In the maxilla, OVX decreased the bone volume in the inter-radicular septum of the second molar. Bisphosphonate treatment was able to prevent this deterioration of the jaw bone. The other investigated maxillary regions were not affected by (un)treated ovariectomy. In the mandible, OVX had a significant negative impact on the jaw bone in the buccal region of the first molar and the inter-radicular region of the third molar. Treatment with ALN was able to prevent this jaw bone loss. At the condyle site, OVX significantly deteriorated the trabecular connectivity and shape, whereas preventive bisphosphonate treatment showed a positive effect on this trabecular bone region. No significant results between the groups were observed for the remaining regions of interest. In summary, our results showed that the effects of ovariectomy-induced osteoporosis are manifested at selected jaw bone regions and that bisphosphonate treatment is capable to prevent these oral bone changes.

Ultrasound in the Assessment of Cranial Bone Thickness

1997 ◽  
Vol 8 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Mohammed M. Elahi ◽  
M. Lucie Lessard ◽  
Souheil Hakim ◽  
Kenneth Watkin ◽  
John Sampalis
Keyword(s):  
Cranial Bone ◽  
Bone Thickness

scholarly journals Targeted ablation of the PTH/PTHrP receptor in osteocytes impairs bone structure and homeostatic calcemic responses

2011 ◽  
Vol 209 (1) ◽  
pp. 21-32 ◽  
Author(s):  
William F Powell ◽  
Kevin J Barry ◽  
Irena Tulum ◽  
Tatsuya Kobayashi ◽  
Stephen E Harris ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Bone Structure ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Blood Calcium ◽  
Low Calcium Diet ◽  
Exon 1 ◽  
Skeletal Homeostasis ◽  
Pthrp Receptor

Parathyroid hormone (PTH) is a major physiologic regulator of calcium, phosphorous, and skeletal homeostasis. Cells of the osteoblastic lineage are key targets of PTH action in bone, and recent evidence suggests that osteocytes might be important in the anabolic effects of PTH. To understand the role of PTH signaling through the PTH/PTHrP receptors (PPR) in osteocytes and to determine the role(s) of these cells in mediating the effects of the hormone, we have generated mice in which PPR expression is specifically ablated in osteocytes. Transgenic mice in which the 10 kb-Dmp1 promoter drives a tamoxifen-inducible Cre-recombinase were mated with animals in which exon 1 of PPR is flanked by lox-P sites. In these animals, osteocyte-selective PPR knockout (Ocy-PPRcKO mice) could be induced by administration of tamoxifen. Histological analysis revealed a reduction in trabecular bone and mild osteopenia in Ocy-PPRcKO mice. Reduction of trabeculae number and thickness was also detected by micro-computed tomography analysis whereas bone volume fraction (BV/TV%) was unchanged. These findings were associated with an increase in Sost and sclerostin expression. When Ocy-PPRcKO mice were subjected to a low-calcium diet to induce secondary hyperparathyroidism, their blood calcium levels were significantly lower than littermate controls. Moreover, PTH was unable to suppress Sost and sclerostin expression in the Ocy-PPRcKO animals, suggesting an important role of PTH signaling in osteocytes for proper bone remodeling and calcium homeostasis.

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