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Bones and fractures
Published in Henry J. Woodford, Essential Geriatrics, 2022
The key components of bone are proteins (especially collagen), cells and calcium salts. Osteoblasts are the cells that form new bone and osteoclasts are the cells that resorb it. They work in balance and, in healthy bone, this produces a constant remodelling process. Their action is coordinated by a number of growth factors, cytokines and hormones. There are two distinct types of bone, termed ‘cortical' and ‘cancellous' (or ‘trabecular'). Long bones are mainly composed of cortical bone and bones of other shapes are mainly composed of cancellous bone (e.g. the pelvis and vertebrae). The metabolism of bone is influenced by a number of external factors. Bone acts as a reservoir of calcium. Vitamin D and parathyroid hormone (PTH) influence its turnover in order to regulate serum calcium levels. The relationship between vitamin D and PTH is shown in Figure 16.1. They are discussed further, along with calcitonin, below.
Mucolipidosis II and III/ (I-cell disease and pseudo-Hurler polydystrophy) N-acetyl-glucosaminyl-l-phosphotransferase deficiency
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
Mucolipidosis II/III shares many of the clinical manifestations of the classic mucopolysaccharidoses. In fact, the roentgenographic characteristics are those of a florid dysostosis multiplex (Figures 83.3–83.8). The films of one of our patients [6] were kept in the teaching file of a medical school department of radiology as exemplifying Hurler disease. The disease was originally described [7] as pseudo-Hurler polydystrophy. There is, however, no mucopolysacchariduria. The long bones are short and thick. The distal radius and ulna tilt toward each other. The proximal phalanges are bullet shaped and the metacarpals are broad distally and pointed proximally. The ribs are broad and spatulate. Vertebral bodies are short and Ll and T12 may be anteriorly beaked (Figures 83.6 and 83.7). There may be early craniosynostosis (Figure 83.8). In other patients, the skull may be normal. There may be hypoplasia of the odontoid. Degenerative changes of the joints, especially the proximal femoral areas, may be characteristic.
The locomotor system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Osteoporosis can be regarded as both a subclinical and clinical disease. Symptomatic osteoporosis develops when bone loss is sufficiently severe that mechanical failure occurs. This is usually seen as: Vertebral crush fractures, which may lead to severe back pain and loss of height. If the fracture wedges anteriorly, kyphosis may result.Long bone fractures, which may follow minor injury. The common sites are the neck of femur and distal radius (typically Colles’ fracture). Forearm fractures are often the first sign of osteoporosis. Femoral neck fractures are a major cause of morbidity and mortality in elderly people.
Distal Femoral Non-Epiphyseal Cortical Chondroblastoma Confirmed with H3F3B p. Lys36Met Mutation
Published in Fetal and Pediatric Pathology, 2023
Haiyan Gu, Lingling Sun, Jiufa Cui, Lan Yu, Jigang Wang
Chondroblastoma is a primary cartilaginous tumor that mainly occurs in the second to early third decades of life with a male predominance (male/female ratio: 2:1) [1]. Most authors agree that it arises from secondary ossification centers in the epiphyseal plates and apophyses of long bones in patients with an immature skeleton or some remnant of it, so the typical localization for chondroblastoma is the epiphysis. A tumor localizing within the metaphysis or diaphysis is generally not considered chondroblastoma. Maheshwari et al. [7] reviewed 690 cases of chondroblastoma in 10 large series and found about 2% were purely metaphyseal, and only one was in the diaphysis. They also reported 7 cases of metaphyseal and diaphyseal chondroblastoma, and most patients were adolescents with a slight female predominance [7]. Previous studies noted that chondroblastoma at non-epiphyseal sites such as short tubular bones or flat bones tended to affect adult patients older than 30, so the etiology of metaphyseal and diaphyseal chondroblastoma may be different from these tumors [11].
Leptin’s Immune Action: A Review Beyond Satiety
Published in Immunological Investigations, 2023
Alice Abend Bardagi, Clarissa dos Santos Paschoal, Giovanna Ganem Favero, Luisa Riccetto, Maria Luisa Alexandrino Dias, Gil Guerra Junior, Giovanna Degasperi
The bone marrow is one of the largest tissues in the body. Protected by the bones, it is found within the central cavities of axial and long bones and is the main physiological site for hematopoiesis in adults, being responsible for the production of erythrocytes, granulocytes, monocytes, lymphocytes, and platelets (Lucas 2021). HSCs are responsible for the generation and renewal of erythroid, myeloid, and lymphoid progenitor cell lineages. HSCs reside in specialized microenvironments known as “niches”, which promote essential elements for the self-renewal ability and generation of cell diversity (Pinho and Frenette 2019). Megakaryocytes, erythrocytes, basophils, neutrophils, eosinophils, and monocytes arise from the myeloid progenitor, while B lymphocytes, T lymphocytes, and natural killer (NK) cells originate from lymphoid progenitors (Zhang et al. 2018).
An update of interbody cages for spine fusion surgeries: from shape design to materials
Published in Expert Review of Medical Devices, 2022
Guangshen Li, Lei Yang, Gang Wu, Zhanyang Qian, Haijun Li
Human bone is cortical in the outer layer and cancellous in the inner layer, in its microstructure, there is a difference in porosity between the two, for long bones and vertebrae, the main stress role is played by the cortical . Therefore, some researchers imitate this structure to design the interbody fusion cage with gradient porosity, and through mechanical tests, it is proved that the design stress distribution in human bone is basically the same and is better than the current commercial interbody fusion cage [113].In addition, some researchers have proposed that the radial (perpendicular to the loading direction) gradient porosity structure can lead to progressive structural failure and has good mechanical properties. The application of this structure to the design of interbody fusion cage can better adapt the upper and lower surface of interbody fusion cage to the shape of endplate, increase the adhesion of interbody fusion cage and endplate, and improve the effect of fusion [114].