Radiation therapy can result in bone injury with the development of fractures and often can lead to delayed and nonunion of bone. There is no prevention or treatment for irradiation-induced bone injury. We irradiated the distal half of the mouse left femur to study the mechanism of irradiation-induced bone injury and found that no mesenchymal stem cells (MSCs) were detected in irradiated distal femora or nonirradiated proximal femora. The MSCs in the circulation doubled at 1 week and increased fourfold after 4 wk of irradiation. The number of MSCs in the proximal femur quickly recovered, but no recovery was observed in the distal femur. The levels of free radicals were increased threefold at 1 wk and remained at this high level for 4 wk in distal femora, whereas the levels were increased at 1 wk and returned to the basal level at 4 wk in nonirradiated proximal femur. Free radicals diffuse ipsilaterally to the proximal femur through bone medullary canal. The blood vessels in the distal femora were destroyed in angiographic images, but not in the proximal femora. The osteoclasts and osteoblasts were decreased in the distal femora after irradiation, but no changes were observed in the proximal femora. The total bone volumes were not affected in proximal and distal femora. Our data indicate that irradiation produces free radicals that adversely affect the survival of MSCs in both distal and proximal femora. Irradiation injury to the vasculatures and the microenvironment affect the niches for stem cells during the recovery period.
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http://dx.doi.org/10.1073/pnas.1015350108 | DOI Listing |
Arch Orthop Trauma Surg
January 2025
Department of Orthopaedics, Wright State University, 30 E Apple St., Suite 2200, Dayton, OH, 45409, USA.
Introduction: We propose and assess the biomechanical stability of medial column screw supplementation in a synthetic distal femur fracture model.
Materials And Methods: Twenty-four low density synthetic femora modeling osteoporotic, intraarticular distal femur fractures with medial metaphyseal comminution were split into two fixation groups: (1) lateral locking distal femur plate (PA- plate alone) and (2) lateral locking distal femur plate with a 6.5 mm fully threaded medial cannulated screw (PWS- plate with screw).
Pediatr Radiol
January 2025
Department of Pediatric Genetics, Istanbul University-Cerrahpaşa, Cerrahpasa Medical Faculty, 34098, Cerrahpasa, Istanbul, Turkey.
Background: Heterozygous TRPV4 mutations cause a group of skeletal dysplasias characterized by short stature, short trunk, and skeletal deformities.
Objective: The aim of this study is to compare the natural history of clinical and radiologic features of patients with different TRPV4-related skeletal dysplasias.
Materials And Methods: Thirteen patients with a mutation in TRPV4 were included in the study, and 11 were followed for a median of 6.
Anat Rec (Hoboken)
December 2024
Laboratorio de Evolución Humana, Universidad de Burgos, Edificio I+D+i/CIBA, Burgos, Spain.
This research delves deeper into previous works on femoral cross-sectional properties during ontogeny by focusing for the first time on the human femoral midneck. The ontogenetic pattern of cross-sectional properties at femoral midneck is established and compared with those at three different femoral locations: the proximal femur, the midshaft, and the distal femur. The study sample includes 99 femora (70 non-adults and 29 adults) belonging to archaeological specimens.
View Article and Find Full Text PDFJ Am Acad Orthop Surg
December 2024
From the Department of Orthopaedic Surgery (Chen, Liu, Gallo, Kusnezov, Chung, Christ, and Heckmann), and the Department of Radiology (Hwang), Keck School of Medicine of USC, Los Angeles, CA.
Bone
March 2025
Department of Health, Nutrition, and Food Sciences, Florida State University, Tallahassee, FL, USA. Electronic address:
Aging leads to progressive bone loss, which is associated with impaired bone and marrow perfusion. The purpose of this study was to determine whether chronic exercise training enhances blood flow to the femur at rest and during exercise, and elucidate whether putative changes in training-induced bone perfusion are associated with alterations in the intrinsic vasomotor properties of the femoral principal nutrient artery (PNA) in old age. Young (4-6 mo old) and old (20-22 mo old) male Fischer-344 rats were either treadmill exercise trained (ET) or remained sedentary (SED).
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