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Frontiers in Physiology 2022Astronauts suffer from a loss of bone mass at a rate of 1.5% per month from lower regions of the body during the course of long-duration (>30 days) spaceflight, a...
Astronauts suffer from a loss of bone mass at a rate of 1.5% per month from lower regions of the body during the course of long-duration (>30 days) spaceflight, a phenomenon that poses important risks for returning crew. Conversely, a gain in bone mass may occur in non-load bearing regions of the body as related to microgravity-induced cephalad fluid shift. Representing non-load bearing regions with mouse calvaria and leveraging the STS-131 (15-day) and BION-M1 (30-day) flights, we examined spatial and temporal calvarial vascular remodeling and gene expression related to microgravity exposure compared between spaceflight (SF) and ground control (GC) cohorts. We examined parasagittal capillary numbers and structures in calvaria from 16 to 23 week-old C57BL/6 female mice (GC, n = 4; SF, n = 5) from STS-131 and 19-20 week-old C57BL/6 male mice (GC, n = 6; SF, n = 6) from BION-M1 using a robust isolectin-IB4 vessel marker. We found that the vessel diameter reduces significantly in mice exposed to 15 days of spaceflight relative to control. Capillarization increases by 30% (SF vs. GC, = 0.054) in SF mice compared to GC mice. The vessel numbers and diameter remain unchanged in BION-M1 mice calvarial section. We next analyzed the parietal pro-angiogenic () and pro-osteogenic gene ( and ) expression in BION-M1 mice using quantitative RT-PCR. gene expression increased 15-fold while gene expression increased 11-fold in flight mice compared to GC. The linkage between vascular morphology and gene expression in the SF conditions suggests that angiogenesis may be important in the regulation of pathological bone growth in non-weight bearing regions of the body. Short-duration microgravity-mediated bone restructuring has implications in planning effective countermeasures for long-duration flights and extraterrestrial human habitation.
PubMed: 35634164
DOI: 10.3389/fphys.2022.893025 -
Dental Materials Journal Jul 2021Hydroxyapatite (HA) [Ca (PO) (OH)] has a high degree of chemical similarity with the mineral composition of animal bone. Hydroxyapatite fiber scaffold (HAF) is a...
Hydroxyapatite (HA) [Ca (PO) (OH)] has a high degree of chemical similarity with the mineral composition of animal bone. Hydroxyapatite fiber scaffold (HAF) is a biological material with a highly interconnected porous structure. We aimed to study the physical and biological characteristics of HAF and compare the osteogenic effects of HAF, natural osteogenic materials (NOM), and carbonate apatite (COAp-DP) in the parietal defects of a rabbit's skull. X-ray analysis and histological assessment showed that HAF followed a trend of early initial osteogenesis and bone trabecular structure formation, especially at the cortical bone portion.Compared to the other two materials, HAF was more absorptive. Results indicated that HAF had the same osteoconductive and new bone formation properties as NOM and COAp-DP. These findings will provide options for future material development and novel protocols for use in surgeries, ultimately leading to better patient outcomes.
Topics: Animals; Bone Regeneration; Durapatite; Osteogenesis; Porosity; Rabbits; Skull; Tissue Scaffolds
PubMed: 33883351
DOI: 10.4012/dmj.2020-327 -
Indian Journal of Otolaryngology and... May 2023Sensitivity of vestibular system to sounds (SVSS) can be measureable by cervical vestibular evoked myogenic potentials (cVEMPs). The aim of this study is to investigate...
Sensitivity of vestibular system to sounds (SVSS) can be measureable by cervical vestibular evoked myogenic potentials (cVEMPs). The aim of this study is to investigate central representation of vestibular system sensitivity to sound. The research was conducted in 2022-2023 by searching English language databases. The criterion for selecting documents was their overlap with the aim of this work. The animals studies were not included. The saccule is stimulated by sounds, that are transmitted through air and bone conduction. Utricle and semicircular canals are activated only by the vibrations. The afferent nerve fibers of the vestibular system project to the temporal, frontal, parietal, primary visual cortex, insula and the cingulate cortex. There is a relationship between normal results of the cVEMPs and these parameters. Improved phonemes recognition scores and word recognition scores in white noise, the efficiency of auditory training, incraed amplitude of the auditory brainstem responses to 500 HZ tone burst. Learning the first words is not only based on the hearing and other senses participate. The auditory object is a three-dimensional imaging in people's minds, when they hear a word. The words expressed by a speaker create different auditory objects in people's minds. Each of these auditory objects has its own color, shape, aroma and characteristics. For the formation of the auditory objects, all senses and whole areas of the brain contribute. Like other senses, central representation of vestibular system sensitivity to sound are also involved in the formation of auditory objects.
PubMed: 37362135
DOI: 10.1007/s12070-023-03829-8 -
Radiology Case Reports Nov 2021Metaplastic meningioma is a rare World Health Organization Grade I meningioma subtype, accounting for 0.2%-1.6% of all meningiomas. Primary extradural meningiomas...
Metaplastic meningioma is a rare World Health Organization Grade I meningioma subtype, accounting for 0.2%-1.6% of all meningiomas. Primary extradural meningiomas represent less than 2% of all meningiomas, with intraosseous meningioma as a subtype of primary extradural meningiomas. Herein, we report the case of a 65-year-old male presenting with headache. His computed tomography scans showed an osteolytic left parietal bone mass, and magnetic resonance imaging revealed hyperintense dots in the mass on T1-weighted images. The mass was then resected and diagnosed on histopathological examination as an intraosseous metaplastic meningioma.
PubMed: 34484535
DOI: 10.1016/j.radcr.2021.07.080 -
Materials (Basel, Switzerland) Jun 2021Fresh compact bone, the candidate graft material for bone regeneration, is usually grafted for horizontal bone augmentation. However, the dense calcified structure...
Fresh compact bone, the candidate graft material for bone regeneration, is usually grafted for horizontal bone augmentation. However, the dense calcified structure inhibits the release of growth factors and limits cellular and vascular perfusion. We aimed to create mechano-chemically altered dense skull bone by ultrasonic treatment, along with partial demineralization using commercially available acidic electrolyzed water (AEW). The parietal skull bone of an 11-month-old Wistar rat was exposed and continuously treated with a piezoelectric ultrasonic scaler tip for 1 min, using AEW (pH 2.3) or distilled water (DW, pH 5.6) as irrigants. Treated parietal bone was removed, cut into plates (5 × 5 × 1 mm), grafted into the back subcutaneous tissues of syngeneic rats, and explanted at 1, 2, and 3 weeks. AEW bone showed an irregular surface, deep nano-microcracks, and decalcified areas. SEM-EDS revealed small amounts of residual calcium content in the AEW bone (0.03%) compared to the DW bone (0.86%). In the animal assay, the AEW bone induced bone at 2 weeks. Histomorphometric analysis showed that the area of new bone in the AEW bone at 2 and 3 weeks was significantly larger. This new combination technique of AEW-demineralization with ultrasonic treatment will improve the surface area and three-dimensional (3D) architecture of dense bone and accelerate new bone synthesis.
PubMed: 34204338
DOI: 10.3390/ma14123347 -
Case Reports in Oncology 2022Hemangiopericytoma/solitary fibrous tumor (HPC/STF) is a rare tumor arising from Zimmerman's pericytes and it is characterized by an aggressive malignancy, with a high...
Hemangiopericytoma/solitary fibrous tumor (HPC/STF) is a rare tumor arising from Zimmerman's pericytes and it is characterized by an aggressive malignancy, with a high tendency for local and distant recurrence. The authors report the case of a middle-aged woman with HPC/SFT of the right parietal bone, which is an extremely rare primary location of involvement. The patient presented with a painful deformity of insidious growth at the right parietal region. Assessment with cranial computed tomography scan and magnetic resonance imaging revealed an expansive lesion at the right parietal bone, with exocranial extension and 27 mm of maximal diameter. Craniotomy with gross tumor removal, duraplasty, and cranioplasty was performed, and the diagnosis of HPC/SFT, WHO grade III, was established by pathological and immunohistochemical analysis. The patient was then evaluated for adjuvant radiation therapy and received a dose of 60 Gy (2 Gy/fraction) with 3D conformal radiotherapy to the surgical bed. The adjuvant treatment was uneventful and, after 8 months of follow-up, there was no suspected local or distant recurrence. The rarity of this diagnosis, its aggressive behavior, and the lack of published data posed several challenges for the treatment management.
PubMed: 36636675
DOI: 10.1159/000525724 -
The effect of nano-hydroxyapatite/chitosan scaffolds on rat calvarial defects for bone regeneration.International Journal of Implant... May 2021This study aims at determining the biological effect of 75/25 w/w nano-hydroxyapatite/chitosan (nHAp/CS) scaffolds on bone regeneration, in terms of fraction of bone...
BACKGROUND
This study aims at determining the biological effect of 75/25 w/w nano-hydroxyapatite/chitosan (nHAp/CS) scaffolds on bone regeneration, in terms of fraction of bone regeneration (FBR), total number of osteocytes (Ost), and osteocyte cell density (CD), as well as its biodegradability.
METHODS
Two critical-size defects (CSDs) were bilaterally trephined in the parietal bone of 36 adult Sprague-Dawley rats (18 males and 18 females); the left remained empty (group A), while the right CSD was filled with nHAp/CS scaffold (group B). Two female rats died postoperatively. Twelve, 11, and 11 rats were euthanized at 2, 4, and 8 weeks post-surgery, respectively. Subsequently, 34 specimens were resected containing both CSDs. Histological and histomorphometric analyses were performed to determine the FBR, calculated as [the sum of areas of newly formed bone in lateral and central regions of interest (ROIs)]/area of the original defect, as well as the Ost and the CD (Ost/mm) in each ROI of both groups (A and B). Moreover, biodegradability of the nHAp/CS scaffolds was estimated via the surface area of the biomaterial (BmA) in the 2nd, 4th, and 8th week post-surgery.
RESULTS
The FBR of group B increased significantly from 2nd to 8th week compared to group A (P = 0.009). Both the mean CD and the mean Ost values of group B increased compared to group A (P = 0.004 and P < 0.05 respectively). Moreover, the mean value of BmA decreased from 2nd to 8th week (P = 0.001).
CONCLUSIONS
Based on histological and histomorphometric results, we support that 75/25 w/w nHAp/CS scaffolds provide an effective space for new bone formation.
Topics: Animals; Bone Regeneration; Chitosan; Durapatite; Female; Male; Osteogenesis; Rats; Rats, Sprague-Dawley
PubMed: 34027572
DOI: 10.1186/s40729-021-00327-w -
iPSC-neural crest derived cells embedded in 3D printable bio-ink promote cranial bone defect repair.Scientific Reports Nov 2022Cranial bone loss presents a major clinical challenge and new regenerative approaches to address craniofacial reconstruction are in great demand. Induced pluripotent...
Cranial bone loss presents a major clinical challenge and new regenerative approaches to address craniofacial reconstruction are in great demand. Induced pluripotent stem cell (iPSC) differentiation is a powerful tool to generate mesenchymal stromal cells (MSCs). Prior research demonstrated the potential of bone marrow-derived MSCs (BM-MSCs) and iPSC-derived mesenchymal progenitor cells via the neural crest (NCC-MPCs) or mesodermal lineages (iMSCs) to be promising cell source for bone regeneration. Overexpression of human recombinant bone morphogenetic protein (BMP)6 efficiently stimulates bone formation. The study aimed to evaluate the potential of iPSC-derived cells via neural crest or mesoderm overexpressing BMP6 and embedded in 3D printable bio-ink to generate viable bone graft alternatives for cranial reconstruction. Cell viability, osteogenic potential of cells, and bio-ink (Ink-Bone or GelXa) combinations were investigated in vitro using bioluminescent imaging. The osteogenic potential of bio-ink-cell constructs were evaluated in osteogenic media or nucleofected with BMP6 using qRT-PCR and in vitro μCT. For in vivo testing, two 2 mm circular defects were created in the frontal and parietal bones of NOD/SCID mice and treated with Ink-Bone, Ink-Bone + BM-MSC-BMP6, Ink-Bone + iMSC-BMP6, Ink-Bone + iNCC-MPC-BMP6, or left untreated. For follow-up, µCT was performed at weeks 0, 4, and 8 weeks. At the time of sacrifice (week 8), histological and immunofluorescent analyses were performed. Both bio-inks supported cell survival and promoted osteogenic differentiation of iNCC-MPCs and BM-MSCs in vitro. At 4 weeks, cell viability of both BM-MSCs and iNCC-MPCs were increased in Ink-Bone compared to GelXA. The combination of Ink-Bone with iNCC-MPC-BMP6 resulted in an increased bone volume in the frontal bone compared to the other groups at 4 weeks post-surgery. At 8 weeks, both iNCC-MPC-BMP6 and iMSC-MSC-BMP6 resulted in an increased bone volume and partial bone bridging between the implant and host bone compared to the other groups. The results of this study show the potential of NCC-MPC-incorporated bio-ink to regenerate frontal cranial defects. Therefore, this bio-ink-cell combination should be further investigated for its therapeutic potential in large animal models with larger cranial defects, allowing for 3D printing of the cell-incorporated material.
Topics: Humans; Mice; Animals; Induced Pluripotent Stem Cells; Osteogenesis; Ink; Neural Crest; Mice, Inbred NOD; Mice, SCID; Cell Differentiation
PubMed: 36333414
DOI: 10.1038/s41598-022-22502-8 -
Frontiers in Cell and Developmental... 2021Adult erythropoiesis is a highly controlled sequential differentiation of hematopoietic stem cells (HSCs) to mature red blood cells in the bone marrow (BM). The bones...
Adult erythropoiesis is a highly controlled sequential differentiation of hematopoietic stem cells (HSCs) to mature red blood cells in the bone marrow (BM). The bones which contain BM are diverse in their structure, embryonic origin, and mode of ossification. This has created substantial heterogeneity in HSCs function in BM of different bones, however, it is not known if this heterogeneity influences erythropoiesis in different bones and different regions of the same bone. In this study, we examined steady state BM erythroid progenitors and precursors from different bones - the femur, tibia, pelvis, sternum, vertebrae, radius, humerus, frontal, parietal bone, and compared all to the femur. Trabecular and cortical regions of the femur were also compared for differences in erythropoiesis. In addition, mouse spleen was studied to determine at which age erythropoietic support by the spleen was lost postnatally. We report that total erythroid cells, and erythroid precursors in the femur are comparable to tibia, pelvis, humerus and sternum, but are significantly reduced in the vertebrae, radius, frontal, and parietal bones. Erythroid progenitors and multipotential progenitor numbers are comparable in all the bones except for reduced number in the parietal bone. In the femur, the epiphysis and metaphysis have significantly reduced number of erythroid precursors and progenitors, multipotential progenitors and myeloid progenitors compared to the diaphysis region. These results show that analysis of erythroid precursors from diaphysis region of the femur is representative of tibia, pelvis, humerus and sternum and have significant implications on the interpretation of the steady-state erythropoiesis finding from adult BM. Postnatal spleen supports erythroid precursors until 6 weeks of age which coincides with reduced number of red pulp macrophages. The residual erythroid progenitor support reaches the adult level by 3 months of age. In conclusion, our findings provide insights to the differences in erythropoiesis between different bones, between trabecular and cortical regions of the femur, and developmental changes in postnatal spleen erythropoiesis.
PubMed: 34055777
DOI: 10.3389/fcell.2021.646646 -
Anatomical Record (Hoboken, N.J. : 2007) Oct 2022A system-by-system approach dominates morphological and evolutionary study; however, some structures that are better understood within the context of an interface...
A system-by-system approach dominates morphological and evolutionary study; however, some structures that are better understood within the context of an interface between two systems or traditional units remain less well understood. As part of a larger goal to clarify aspects of skull-neck boundary evolution, we herein describe the morphology and development of the occiput and atlas-axis complex in the crocodylian Alligator mississippiensis. We apply micro-computed tomography scanning, clearing and double staining, and histological analyses to skull-neck boundary structures at three stages of development (embryonic stage 22, 23, and hatchling). Regions of ossification that could possibly pertain to a postparietal were found adjacent to the parietal bone and supraoccipital; however, these were not deemed convincing and are considered part of the supraoccipital. Within the atlas-axis complex, the proatlas appears as two discrete cartilaginous elements in Stage 22 that ossify together at Stage 23. Posterior to the proatlas, the atlas-axis complex is composed of two centra, each with cervical ribs ventrally and neural arches dorsally that begin ossifying at Stage 23. Histology and clearing and staining of Stages 22 and 23 embryos reveal a discrete atlas intercentrum applied to the ventral part of the occipital condyle of the skull. Posterior to this is a cartilage that appears to be a co-chondrified atlas pleurocentrum, axis intercentrum, and axis pleurocentrum. Ossification of this cartilaginous structure produces discrete atlas inter- and pleurocentra, as well as a singular axis centrum. Together these data are discussed with reference to clarifying historical discrepancies concerning elements at the crocodylian skull-neck boundary.
Topics: Alligators and Crocodiles; Animals; Head; Parietal Bone; Skull; X-Ray Microtomography
PubMed: 34846803
DOI: 10.1002/ar.24834