Show Advanced Search

REFINE YOUR SEARCH:

Containing Text
- - -
+
Filter by author or institution
GO
Filter by publication date
From:
October, 2006
Until:
Today
Filter by journal section

Filter by science education

 
 
Parathyroid Hormone: A polypeptide hormone (84 amino acid residues) secreted by the Parathyroid glands which performs the essential role of maintaining intracellular Calcium levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of Calcium from Bone, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.

Bone Remodeling

JoVE 10866

Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.

Parathyroid hormone (PTH) maintains homeostatic control of blood calcium levels by regulating bone resorption. PTH is released from the parathyroid glands in response to low levels of calcium in the blood. It stimulates osteoblasts to produce immune molecules that promote the differentiation of precursor cells into osteoclasts. Activation of osteoclasts promotes bone resorption, causing the mineralized bone matrix to break down and release calcium into the blood. When blood calcium levels are restored, a negative-feedback loop prevents further release of PTH. Osteoporosis is a disease in which bone resorption exceeds bone formation, resulting in reduced bone density. Osteoporosis is more prevalent in women, especially after menopause. This is due to the critical role played by the female sex hormone—estrogen—in bone remodeling. Estrogen limits the formation of osteoclasts and promotes their destruction via apoptosis. This ensures that bone formation is higher than bone resorption. However, estrogen levels decli

 Core: Biology

Magnetic-Activated Cell Sorting Strategies to Isolate and Purify Synovial Fluid-Derived Mesenchymal Stem Cells from a Rabbit Model

1Postgraduate institution, Guangzhou Medical University, 2Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, 3Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Laboratory of Digital Orthopaedic Engineering, Shenzhen Second People's Hospital (The First Hospital Affiliated to Shenzhen University), 4Department of Chemistry, Chinese University of Hong Kong, 5Shenzhen Kangning Hospital, Shenzhen Mental Health Center

JoVE 57466

 Biology

Calvarial Model of Bone Augmentation in Rabbit for Assessment of Bone Growth and Neovascularization in Bone Substitution Materials

1Division of Fixed Prosthodontics and Biomaterials, Biomaterials Laboratory, University of Geneva, University Clinic of Dental Medicine, 2Department of Surgery, Division of Oral and Maxillofacial Surgery (HUG), Unity of Oral Surgery and Implantology, University of Geneva, University Clinic of Dental Medicine, 3Department of Surgery, Division of Oral and Maxillofacial surgery (HUG), Laboratory of Oral & Maxillofacial Pathology, University of Geneva, University Clinic of Dental Medicine, 4Division of Fixed Prosthodontics and Biomaterials, University of Geneva, University Clinic of Dental Medicine

JoVE 59976

 Bioengineering

Isolation, Purification, and Differentiation of Osteoclast Precursors from Rat Bone Marrow

1Laboratory of New Techniques of Restoration & Reconstruction, Institute of Traumatology & Orthopedics, Nanjing University of Chinese Medicine, 2TCM Nursing Intervention Laboratory of Chronic Disease Key Laboratory, Nanjing University of Chinese Medicine, 3Jiangsu Key Laboratory of Chinese Medicine Processing, Engineering Center of State Ministry of Education for Standardization of Chinese Medicine Processing, Nanjing University of Chinese Medicine, 4Department of Traumatology and Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine

JoVE 58895

 Biology

Two Techniques to Create Hypoparathyroid Mice: Parathyroidectomy Using GFP Glands and Diphtheria-Toxin-Mediated Parathyroid Ablation

1Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, 2West China School of Stomatology, Sichuan University, 3Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, 4State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University

JoVE 55010

 Medicine
12
More Results...