Bone Remodeling Under Pathological Conditions

2015 ◽  
pp. 17-27 ◽  
Author(s):  
Wenmei Xiao ◽  
Shuai Li ◽  
Sandra Pacios ◽  
Yu Wang ◽  
Dana T. Graves
Keyword(s):  
Bone Remodeling ◽  
Pathological Conditions

scholarly journals Friend or Foe? Essential Roles of Osteoclast in Maintaining Skeletal Health

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Haixing Wang ◽  
Guangpu Yang ◽  
Yinbo Xiao ◽  
Guotian Luo ◽  
Gang Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Formation ◽  
Bone Remodeling ◽  
Coupling Effect ◽  
Osteoclast Differentiation ◽  
Cell Contact ◽  
Skeletal Health ◽  
Normal Bone ◽  
Secreted Factors ◽  
Pathological Conditions

Heightened activity of osteoclast is considered to be the culprit in breaking the balance during bone remodeling in pathological conditions, such as osteoporosis. As a “foe” of skeletal health, many antiosteoporosis therapies aim to inhibit osteoclastogenesis. However, bone remodeling is a dynamic process that requires the subtle coordination of osteoclasts and osteoblasts. Severe suppression of osteoclast differentiation will impair bone formation because of the coupling effect. Thus, understanding the complex roles of osteoclast in maintaining proper bone remodeling is highly warranted to develop better management of osteoporosis. This review aimed to determine the varied roles of osteoclasts in maintaining skeletal health and to highlight the positive roles of osteoclasts in maintaining normal bone remodeling. Generally, osteoclasts interact with osteocytes to initiate targeted bone remodeling and have crosstalk with mesenchymal stem cells and osteoblasts via secreted factors or cell-cell contact to promote bone formation. We believe that a better outcome of bone remodeling disorders will be achieved when proper strategies are made to coordinate osteoclasts and osteoblasts in managing such disorders.

scholarly journals Vitamin D and Platelets: A Menacing Duo in COVID-19 and Potential Relation to Bone Remodeling

2021 ◽  
Vol 22 (18) ◽  
pp. 10010
Author(s):  
Francesca Salamanna ◽  
Melania Maglio ◽  
Maria Sartori ◽  
Maria Paola Landini ◽  
Milena Fini
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Bone Remodeling ◽  
Bone Health ◽  
Feedback Loop ◽  
Mineral Metabolism ◽  
Bone Fragility ◽  
Preliminary Information ◽  
Pathological Conditions ◽  
Global Data

Global data correlate severe vitamin D deficiency with COVID-19-associated coagulopathy, further suggesting the presence of a hypercoagulable state in severe COVID-19 patients, which could promote thrombosis in the lungs and in other organs. The feedback loop between COVID-19-associated coagulopathy and vitamin D also involves platelets (PLTs), since vitamin D deficiency stimulates PLT activation and aggregation and increases fibrinolysis and thrombosis. Vitamin D and PLTs share and play specific roles not only in coagulation and thrombosis but also during inflammation, endothelial dysfunction, and immune response. Additionally, another ‘fil rouge’ between vitamin D and PLTs is represented by their role in mineral metabolism and bone health, since vitamin D deficiency, low PLT count, and altered PLT-related parameters are linked to abnormal bone remodeling in certain pathological conditions, such as osteoporosis (OP). Hence, it is possible to speculate that severe COVID-19 patients are characterized by the presence of several predisposing factors to bone fragility and OP that may be monitored to avoid potential complications. Here, we hypothesize different pervasive actions of vitamin D and PLT association in COVID-19, also allowing for potential preliminary information on bone health status during COVID-19 infection.

Thrombospondins in bone remodeling and metastatic bone disease

2020 ◽  
Vol 319 (6) ◽  
pp. C980-C990
Author(s):  
Laura Carminati ◽  
Giulia Taraboletti
Keyword(s):  
Bone Metastasis ◽  
Bone Remodeling ◽  
Cancer Metastasis ◽  
Bone Cells ◽  
Bone Homeostasis ◽  
Matricellular Proteins ◽  
Metastatic Niche ◽  
Tissue Microenvironment ◽  
Pathological Conditions ◽  
Wide Range

Thrombospondins (TSPs) are a family of five multimeric matricellular proteins. Through a wide range of interactions, TSPs play pleiotropic roles in embryogenesis and in tissue remodeling in adult physiology as well as in pathological conditions, including cancer development and metastasis. TSPs are active in bone remodeling, the process of bone resorption (osteolysis) and deposition (osteogenesis) that maintains bone homeostasis. TSPs are particularly involved in aberrant bone remodeling, including osteolytic and osteoblastic skeletal cancer metastasis, frequent in advanced cancers such as breast and prostate carcinoma. TSPs are major players in the bone metastasis microenvironment, where they finely tune the cross talk between tumor cells and bone resident cells in the metastatic niche. Each TSP family member has different effects on the differentiation and activity of bone cells—including the bone-degrading osteoclasts and the bone-forming osteoblasts—with different outcomes on the development and growth of osteolytic and osteoblastic metastases. Here, we overview the involvement of TSP family members in the bone tissue microenvironment, focusing on their activity on osteoclasts and osteoblasts in bone remodeling, and present the evidence to date of their roles in bone metastasis establishment and growth.

scholarly journals The role of cytokines in bone remodeling and the pathogenesis of postmenopausal osteoporosis

2020 ◽  
Vol 11 (2) ◽  
pp. 6-18
Author(s):  
G. A. Ignatenko ◽  
I. G. Nemsadze ◽  
E. D. Mirovich ◽  
A. V. Churilov ◽  
E. A. Maylyan ◽  
...  
Keyword(s):  
Postmenopausal Osteoporosis ◽  
Bone Remodeling ◽  
Proinflammatory Cytokines ◽  
Scientific Knowledge ◽  
Crucial Role ◽  
Literature Search ◽  
Web Of Science ◽  
Systematic Literature Search ◽  
Pathological Conditions

About 20 years ago osteoimmunology was identified as new field of scientific knowledge. It studies patterns of immune and bone system interactions in normal and pathological conditions. The osteoimmunology achievements have fundamentally changed our ideas about the pathogenesis of human skeleton diseases, including osteoporosis. This review presents cytokines key role in physiological and pathological bone remodeling. The issues of interaction between cytokines, osteoblasts and osteoclasts are described in detail. The crucial role of proinflammatory cytokines increased production by immunocompetent cells in the postmenopausal osteoporosis development has been characterized. Pubmed, Scopus, Web of Science, MedLine, eLIBRARY.RU databases were used for systematic literature search.

Morphological and elemental analysis of isolated incubated frog retina-choroid

1984 ◽  
Vol 42 ◽  
pp. 298-299
Author(s):  
B. J. Panessa-Warren ◽  
J. B. Warren ◽  
H. W. Kraner
Keyword(s):  
Elemental Analysis ◽  
Pigment Epithelium ◽  
Human Retina ◽  
Healthy Individuals ◽  
Anterior Portion ◽  
Pathological Conditions ◽  
Frog Retina ◽  
Isolated Retina ◽  
Vertebrate Eye ◽  
Retina Pigment Epithelium

Our previous studies have demonstrated that abnormally high amounts of calcium (Ca) and zinc (Zn) can be accumulated in human retina-choroid under pathological conditions and that barium (Ba), which was not detected in the eyes of healthy individuals, is deposited in the retina pigment epithelium (RPE), and to a lesser extent in the sensory retina and iris. In an attempt to understand how these cations can be accumulated in the vertebrate eye, a morphological and microanalytical study of the uptake and loss of specific cations (K, Ca,Ba,Zn) was undertaken with incubated Rana catesbiana isolated retina and RPE preparations. Large frogs (650-800 gms) were dark adapted, guillotined and their eyes enucleated in deep ruby light. The eyes were hemisected behind the ora serrata and the anterior portion of the eye removed. The eyecup was bisected along the plane of the optic disc and the two segments of retina peeled away from the RPE and incubated.

An Ultrastructural Study of the Proliferation Patterns of the Reserve Cells of the Human Cervix Uteri

1972 ◽  
Vol 30 ◽  
pp. 80-81
Author(s):  
Takanori Sohda ◽  
Hiroshi Saito ◽  
Goro Asano ◽  
Katsunari Fukushi ◽  
Katsuya Suzuki ◽  
...  
Keyword(s):  
Ultrastructural Study ◽  
Age Groups ◽  
Point Of View ◽  
University Hospital ◽  
Cervix Uteri ◽  
Morphological Aspect ◽  
Functional Aspect ◽  
Pathological Conditions ◽  
Human Cervix ◽  
Morphological Patterns

Recently, the functional aspect as well as morphological aspect of the reserve cells in the cervix uteri drew much attention in view of the carcinogenesis in squamocolumunar junction. In this communication, the authors elucidate the ultrastructural features of the reserve cells in patients of various age groups visiting our university hospital and affiliated hospital.From conventional light microscopic point of view, the reserve cells tend to be pronounced in various pathological conditions, such as the persisting inflammation, proliferative disorders and irritation of hormones. The morphological patterns of the reserve cells from various stage and degree of irritation were observed.

Surface Ultrastructure of Human Ectocervix in Certain Pathological Conditions

1985 ◽  
Vol 43 ◽  
pp. 570-571
Author(s):  
S. Mukherjee ◽  
T. Guha ◽  
B. Chakrabarti ◽  
P. Chakrabarti
Keyword(s):  
Epithelial Cells ◽  
Marked Reduction ◽  
Squamous Epithelium ◽  
Malignant Tumour ◽  
Surface Ultrastructure ◽  
Normal Tissues ◽  
Pathological Conditions ◽  
Hexagonal Shape ◽  
Columnar Cells ◽  
Scanning Electron

The cervix is an important organ in reproduction. Its malfunction is frequently a factor for infertility. Ectocervix region does not appear to have received much attention although many studies have been reported on the endocervix. We report here our SEM observations on ectocervix in certain pathological conditions compared to normal ectocervix.Ectocervix specimens from human females with specific pathological disorders were processed for Scanning Electron Microscopy by conventional method and they were examined in a Philips SEM.The normal ectocervix is lined by flat layer of squamous epithelial cells with microridges (Fig. 1). These cells are known to be formed from columnar cells through metaplastic transformation. The cells of carcinoma-bearing ectocervix show a disorganised appearance (Fig. 2). In non-malignant tumour surface some cuboidal and few columnar cells were seen (Fig. 3). A cyst appears like an overgrowth on the surface of the squamous epithelium (Fig. 4). In ulcerated ectocervix a marked reduction of epithelial cells are observed (Fig. 5); the cells are devoid of microridges and, the large polygonal cells, as observed in normal tissues, have somehow acquired comparatively small hexagonal shape

Does short-term administration of glucagon-like peptide type 2 affect bone mass and markers of bone remodeling in short bowel patients?

2001 ◽  
Vol 120 (5) ◽  
pp. A314-A314
Author(s):  
K HADERSLEV ◽  
P JEPPESEN ◽  
B HARTMANN ◽  
J THULESEN ◽  
J GRAFF ◽  
...  
Keyword(s):  
Bone Mass ◽  
Bone Remodeling ◽  
Short Term ◽  
Short Bowel ◽  
Term Administration ◽  
Glucagon Like Peptide

Non-Linear Dynamics of Cardiovascular Variability Signals

1994 ◽  
Vol 33 (01) ◽  
pp. 81-84 ◽  
Author(s):  
S. Cerutti ◽  
S. Guzzetti ◽  
R. Parola ◽  
M.G. Signorini
Keyword(s):  
Dimensional Space ◽  
Severe Heart Failure ◽  
Parametric Models ◽  
Deterministic Systems ◽  
Finite Dimensional ◽  
Return Maps ◽  
Pathological Conditions ◽  
Non Linear ◽  
Space State

Abstract:Long-term regulation of beat-to-beat variability involves several different kinds of controls. A linear approach performed by parametric models enhances the short-term regulation of the autonomic nervous system. Some non-linear long-term regulation can be assessed by the chaotic deterministic approach applied to the beat-to-beat variability of the discrete RR-interval series, extracted from the ECG. For chaotic deterministic systems, trajectories of the state vector describe a strange attractor characterized by a fractal of dimension D. Signals are supposed to be generated by a deterministic and finite dimensional but non-linear dynamic system with trajectories in a multi-dimensional space-state. We estimated the fractal dimension through the Grassberger and Procaccia algorithm and Self-Similarity approaches of the 24-h heart-rate variability (HRV) signal in different physiological and pathological conditions such as severe heart failure, or after heart transplantation. State-space representations through Return Maps are also obtained. Differences between physiological and pathological cases have been assessed and generally a decrease in the system complexity is correlated to pathological conditions.

A Computerized Coding System for Processing Basic Histopathological Changes – Application to Vascular Pathology

1986 ◽  
Vol 25 (03) ◽  
pp. 139-142 ◽  
Author(s):  
A. Mauriello ◽  
Y. Sambuy ◽  
E. Bonanno ◽  
A. Orlandi ◽  
G. Palmieri ◽  
...  
Keyword(s):  
Vascular Wall ◽  
Final Diagnosis ◽  
Vascular Pathology ◽  
Histopathological Study ◽  
Coding System ◽  
Histopathological Changes ◽  
Histological Changes ◽  
Pathological Conditions ◽  
Computer Based ◽  
Sufficient Space

SummaryAmong the numerous existing computer-based systems for processing pathological data, none contains sufficient space for encoding data on the basic cytological or histological changes of a certain organ or tissue, upon which the final diagnosis is based.An “analytical record” was constructed listing all the basic changes that can be encountered in the various pathological conditions of the vascular wall. The data collected on the “analytical record” were coded by means of an alphanumeric code and stored in an Apple II 48 K minicomputer.The advantages of this system include the computerization of the data by non-specialized personnel and the possibility to’ quantitatively analyze the histocytopathological parameters used for diagnosis in vascular pathology. This coding system may easily be adapted, with minor modifications, to the histopathological study of other organs and tissues.

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