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Bone Marrow: The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.

Bone Structure

JoVE 10864

Within the skeletal system, the structure of a bone, or osseous tissue, can be exemplified in a long bone, like the femur, where there are two types of osseous tissue: cortical and cancellous.

Covering the cortical, or compact bone, is a membrane called the periosteum, which contains connective tissue, capillaries, and nerves. The outer, solid layer—found along the diaphysis, the shaft—forms a dense protective shell around the medullary canal—the cavity that stores yellow bone marrow, composed primarily of fat cells. This space is also covered in a thin lining—the endosteum in which bone growth, remodeling, and repair occur. Within the dense layer of cortical bone are osteons—structural units, arranged in concentric rings called lamellae, that contain osteoblasts—cells critical for bone formation and growth. These cells eventually mature into osteocytes in the hollow space, the lacuna. Through the center of each osteon runs the Haversian canal, which contains more blood and lymphatic vessels, as well as nerve fibers. Towards the rounded ends of the long bone, the epiphyses is the second type of osseous tissue, known as the cancellous, or spongy, bone. This inner layer is composed of a honeycomb-like network of trabeculae—grouped arrangements that form along the lines of stress points to maximize strengt

 Core: Musculoskeletal System

Comprehensive Protocol to Sample and Process Bone Marrow for Measuring Measurable Residual Disease and Leukemic Stem Cells in Acute Myeloid Leukemia

1Department of Hematology, VU University Medical Center, 2Pediatric Oncology/Hematology, VU University Medical Center, 3Janssen Research & Development, LLC, 4Princess Máxima Center for Pediatric Oncology

JoVE 56386

 Cancer Research

Database-guided Flow-cytometry for Evaluation of Bone Marrow Myeloid Cell Maturation

1Department of Hematology, University Hospital of Saint-Etienne, 2Department of Immunology, University Hospital of Grenoble-Alpes, 3Department Hematology, University Hospital of Clermont-Ferrand, 4Department of Immunology, University Hospital of Nice, 5Department of Biopathology, Institute Paoli-Calmettes, 6Department of Hematology, University Hospital of Lille

JoVE 57867

 Medicine

An In Vivo Mouse Model to Measure Naïve CD4 T Cell Activation, Proliferation and Th1 Differentiation Induced by Bone Marrow-derived Dendritic Cells

1LamImSys Lab, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 2LamImSys Lab, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 3CIBER de Enfermedades Cardiovasculares

JoVE 58118

 Immunology and Infection

Humoral Immune Responses

JoVE 10897

The humoral immune response, also known as the antibody-mediated immune response, targets pathogens circulating in “humors,” or extracellular fluids, such as blood and lymph. Antibodies target invading pathogens for destruction via multiple defense mechanisms, including neutralization, opsonization, and activation of the complement system. Patients that are impaired in the production of antibodies suffer from severe and frequent infections by common pathogens and unusual pathogens. B lymphocytes, also called B cells, detect pathogens in the blood or lymph system. Although B cells originate in the bone marrow, their name is derived from a specialized organ in birds in which B cells were first discovered, the bursa of Fabricius. After release from the bone marrow, B cells mature in secondary lymphoid tissues, such as the spleen, lymph nodes, tonsils and mucosa-associated lymphoid tissue throughout the body. B cells bind to specific parts of a pathogen, called antigens, via their B cell receptors. In addition to antigen binding, B cells require a second signal for activation. This signal can be provided by helper T cells or, in some cases, by the antigen itself. When both stimuli are present, B cells form germinal centers, where they proliferate into plasma cells and memory B cells. All cells that are derived from a common ancestral B c

 Core: Immune System

Cell-mediated Immune Responses

JoVE 10896

The cell-mediated immune system is the host’s primary response against invasive bacteria and viruses that cause intracellular infections. It is also essential for fighting against and destroying cancer cells. Furthermore, the cell-mediated immune system plays a role in the rejection of organ transplants or graft tissue.

Phagocytic cells of the innate immune system, such as macrophages or dendritic cells, are the first to recognize a foreign particle. These cells engulf the foreign particle and digest it. Small molecules of the foreign particle, called antigens, remain intact and are presented at the surface of the phagocytic cell. The presentation is facilitated by proteins of the major histocompatibility complex (MHC), which binds the antigen and protrude from the cell. The phagocytic cell is therefore also called an antigen presenting cell (APC). The MHC-antigen complex activates cells of the adaptive immune system, which eventually fight the source of the foreign particle. T cells are a type of lymphocyte that are named after their location of maturation—the thymus. In the thymus, precursor T cells differentiate into two main types, CD4+ and CD8+ T cells. These cell types are named after the surface receptor that determines the cell’s function. All T cells carry T-cell receptors, but the coreceptor CD4

 Core: Immune System

Inflammation

JoVE 10902

In response to tissue injury and infection, mast cells initiate inflammation. Mast cells release chemicals that increase the permeability of adjacent blood capillaries and attract additional immune cells to the wound or site of infection. Neutrophils are phagocytic leukocytes that exit the bloodstream and engulf invading microbes. Blood clotting platelets seal the wound and fibers create a scaffold for wound healing. Macrophages engulf aging neutrophils to end the acute inflammatory response. Tissue injury and infection are the primary causes of acute inflammation. Inflammation protects the body by eliminating the cause of tissue injury and initiating the removal of cell debris resulting from the initial damage and related immune cell activity. Inflammation involves mediators of both the innate and adaptive immune system. Proper regulation of inflammation is crucial to clear the pathogen and remove cell debris without overly damaging healthy tissue in the process. If inflammatory processes are not properly regulated, chronic inflammation can arise that is often fatal. Mast cells are the first to respond to tissue injury, as they are primarily located in areas that have contact with the exterior: the skin, gut, and airways. Mast cells have an arsenal of receptors on their cell surface and can hence be activated by a wide variety of stimuli, such as mi

 Core: Immune System

Adult Stem Cells

JoVE 10810

Stem cells are undifferentiated cells that divide and produce more stem cells or progenitor cells that differentiate into mature, specialized cell types. All the cells in the body are generated from stem cells in the early embryo, but small populations of stem cells are also present in many adult tissues including the bone marrow, brain, skin, and gut. These adult stem cells typically produce the various cell types found in that tissue—to replace cells that are damaged or to continuously renew the tissue. The epithelium lining the small intestine is continuously renewed by adult stem cells. It is the most rapidly replaced tissue in the human body, with most cells being replaced within 3-5 days. The intestinal epithelium consists of thousands of villi that protrude into the interior of the small intestine—increasing its surface area to aid in the absorption of nutrients. Intestinal stem cells are located at the base of invaginations called crypts that lie between the villi. They divide to produce new stem cells, as well as daughter cells (called transit amplifying cells) that divide rapidly, move up the villi and differentiate into all the cell types in the intestinal epithelium, including absorptive, goblet, enteroendocrine, and Paneth cells. These mature cells continue to move up the villi as they carry out their functions, except Paneth cell

 Core: Biotechnology

Translation

JoVE 10795

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA) and other proteins are involved in the production of the chain of amino acids—the polypeptide. Proteins are called the “building blocks” of life because they make up the vast majority of all organisms—from muscle fibers to hairs on your head to components of your immune system—and the blueprint for each and every one of those proteins is encoded by the genes found in the DNA of every cell. The central dogma in biology dictates that genetic information is converted into functional proteins by the processes of transcription and translation. Eukaryotes have a membrane-bound nucleus where mRNA is transcribed from DNA. After transcription, mRNA is shuttled out of the nucleus to be translated into a chain of amino acids—a polypeptide—and eventually, a functional protein. This can take place in the cytoplasm or in the rough endoplasmic reticulum, where the polypeptides are further modified. By contrast, prokaryotes lack a nuclear compartment, so translation in prokaryotes takes place in the cytoplasm,

 Core: DNA Structure and Function

Physiology of the Circulatory System- Concept

JoVE 10625

Homeostasis

Conditions in the external environment of an organism can change rapidly and drastically. To survive, organisms must maintain a fairly constant internal environment, which involves continuous regulation of temperature, pH, and other factors. This balanced state is known as homeostasis, which describes the processes by which organisms maintain their optimal internal…

 Lab Bio

Automated Quantification of Hematopoietic Cell – Stromal Cell Interactions in Histological Images of Undecalcified Bone

1Immunodynamics, German Rheumatism Research Center, a Leibniz Institute, 2Biophysical Analytics, German Rheumatism Research Center, a Leibniz Institute, 3Max-Delbrück Center for Molecular Medicine, 4Wimasis GmbH, 5Immunodynamics and Intravital Imaging, Charité - University of Medicine

JoVE 52544

 Developmental Biology

Tissue Regeneration with Somatic Stem Cells

JoVE 5339

Somatic or adult stem cells, like embryonic stem cells, are capable of self-renewal but demonstrate a restricted differentiation potential. Nonetheless, these cells are crucial to homeostatic processes and play an important role in tissue repair. By studying and manipulating this cell population, scientist may be able to develop new regenerative therapies for injuries and diseases.


 Developmental Biology

An Introduction to Stem Cell Biology

JoVE 5331

Cells that can differentiate into a variety of cell types, known as stem cells, are at the center of one of the most exciting fields of science today. Stem cell biologists are working to understand the basic mechanisms that regulate how these cells function. These researchers are also interested in harnessing the remarkable potential of stem cells to treat human diseases.


Here,…

 Developmental Biology

Blood Withdrawal I

JoVE 10246

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN


Blood collection is a common requirement for research studies that involve mice and rats. The method of blood withdrawal in mice and rats is dependent upon the volume of blood needed, the frequency of the sampling, the health status of the …

 Lab Animal Research

Whole Organ Tissue Culture

JoVE 5799

Whole organs can be cultured ex vivo using specialized bioreactors, with the goal of repairing or replacing entire organs. This method uses a donor organ that is stripped of all cells, leaving behind the three-dimensional structure, and is then repopulated with new cells. This video demonstrates the whole organ culture of lungs, and shows how a dynamic culture…

 Bioengineering

Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts

1Skeletal Biotech Laboratory, The Hebrew University–Hadassah Faculty of Dental Medicine, 2Department of Surgery, Cedars-Sinai Medical Center, 3Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 4Biomedical Imaging Research Institute, Cedars-Sinai Medical Center

JoVE 53459

 Bioengineering

Visualizing Angiogenesis by Multiphoton Microscopy In Vivo in Genetically Modified 3D-PLGA/nHAp Scaffold for Calvarial Critical Bone Defect Repair

1Center for Translational Medicine Research and Development, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 2Department of Orthopedic Surgery, Maastricht UMC+, 3Department of Orthopaedic Surgery, University Hospital RWTH, 4Research Laboratory for Biomedical Optics and Molecular Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences

JoVE 55381

 Bioengineering

Bone Marrow Transplantation Platform to Investigate the Role of Dendritic Cells in Graft-versus-Host Disease

1Cancer Division, Burnett School of Biomedical Sciences, University of Central Florida, 2Department of Biochemistry, Hanoi University of Pharmacy, 3Center for Cardiovascular Regeneration, Department of Cardiovascular Sciences, Houston Methodist Research Institute, 4Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, 5Division of Cancer Control and Population Sciences, University of Pittsburgh Medical Center, Hillman Cancer Center

Video Coming Soon

JoVE 60083

 JoVE In-Press

Construction of Defined Human Engineered Cardiac Tissues to Study Mechanisms of Cardiac Cell Therapy

1Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, 2The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, 3Stem Cell & Regenerative Medicine Consortium, LKS Faculty of Medicine, University of Hong Kong

JoVE 53447

 Bioengineering

Next Generation Sequencing for the Detection of Actionable Mutations in Solid and Liquid Tumors

1Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 2Division of Hematology/Oncology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 3Abramson Cancer Center

JoVE 52758

 Cancer Research

Using the BLT Humanized Mouse as a Stem Cell based Gene Therapy Tumor Model

1Department of Medicine, Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, 2UCLA AIDS Institute, 3Eli & Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, 4Department of Medical and Molecular Pharmacology, David Geffen School of Medicine at UCLA, 5Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine at UCLA

JoVE 4181

 Immunology and Infection
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