Collagen is the most abundant protein in the body and provides structural support throughout the body. It is composed of three polypeptide chains that form a triple helical structure. There are many types of collagen with varying structures and tissue distributions. Collagen type I is the main collagen in bone, skin and tendon. Type II collagen forms cartilage. Collagen degradation and remodeling is mediated by collagenases and other matrix metalloproteinases and is important for tissue repair and pathology when excessive.
Connective and supporting tissues provide structural support, allow for nutrient exchange, and aid in protection and repair. They are primarily composed of extracellular matrix containing fibers and ground substance.
The ground substance is a gel-like material made of glycosaminoglycans, proteoglycans, and glycoproteins. It fills spaces between cells and fibers. Fibers include collagen, reticular, and elastic fibers which provide strength, flexibility, and resilience. Collagen is the most abundant fiber and forms strong fibrils and bundles.
The extracellular matrix provides structure and allows for nutrient/waste transfer between cells and blood. It is composed of ground substance, fibers, and tissue fluid. Glycosaminoglycans such
Collagen and elastin are fibrous proteins that provide structure and elasticity to connective tissues in the body. Collagen is abundant in skin, bone, tendons and cartilage. It forms strong fibers or networks through a triple helix structure. Elastin provides elasticity to tissues like lungs and blood vessels through a rubber-like polymer. Defects in these proteins can cause diseases like brittle bone disease or emphysema.
Collagen is the most abundant protein in mammals and forms the main fibrous component of connective tissues like skin, bone and cartilage. There are many types of collagen that vary in structure and function. Collagen provides strength, support and elasticity to tissues. It is synthesized through a complex process involving post-translational modifications. Collagen in the periodontium includes types I, III, IV, V, VI and XII which provide structure and allow for adaptation to forces. The periodontal ligament has the most rapid collagen turnover of tissues in the body to enable response to occlusion forces.
Collagen is the predominant extracellular matrix component of the periodontium. It is composed of fibrous proteins that form triple helical structures. There are many types of collagen that have been identified, with types I, III, V, and XII being present in the periodontium. Type I collagen is the most abundant and provides structural support and tensile strength to tissues like the periodontal ligament that experience mechanical forces.
The gingival connective tissue consists of collagen fibers, fibroblasts, macrophages, mast cells, and other cells within a ground substance. Collagen types I and III are predominant and provide strength and flexibility. Fibroblasts synthesize collagen and other proteins that make up the extracellular matrix. Mast cells, macrophages, and other immune cells are also present and help defend against pathogens. The connective tissue provides structure, nutrition, and immune function to support the overlying epithelium.
The extracellular matrix (ECM) is an organized network of extracellular materials that surrounds cells. One type of ECM is the basement membrane, a thin sheet that underlies epithelial tissues. The ECM is composed of collagen, elastin, proteoglycans, and structural glycoproteins. Collagen is the most abundant protein in the ECM and forms fibrils that provide structural support and determine the shape of tissues. Collagen molecules assemble into fibrils outside of cells through a process involving post-translational modifications.
The extracellular matrix (ECM) is an organized network of extracellular materials that surrounds cells. One type of ECM is the basement membrane, a thin sheet that underlies epithelial tissues. The ECM is composed of collagen, elastin, proteoglycans, and structural glycoproteins. Collagen is the most abundant protein in the ECM and forms fibrils that provide structural support and determine the shape of tissues. Collagen molecules assemble into fibrils outside of cells through a process involving post-translational modifications.
Collagen and elastin are fibrous proteins found in the extracellular matrix that provide structure. Collagen is the most abundant protein in the body and forms rope-like triple helices from three polypeptide chains. There are over 25 types of collagen that form fibrils, networks, or are associated with fibrils. Collagen synthesis involves post-translational modifications before assembly into fibers and crosslinking outside cells. Abnormalities in collagen synthesis and structure can cause disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta.
Connective and supporting tissues provide structural support, allow for nutrient exchange, and aid in protection and repair. They are primarily composed of extracellular matrix containing fibers and ground substance.
The ground substance is a gel-like material made of glycosaminoglycans, proteoglycans, and glycoproteins. It fills spaces between cells and fibers. Fibers include collagen, reticular, and elastic fibers which provide strength, flexibility, and resilience. Collagen is the most abundant fiber and forms strong fibrils and bundles.
The extracellular matrix provides structure and allows for nutrient/waste transfer between cells and blood. It is composed of ground substance, fibers, and tissue fluid. Glycosaminoglycans such
Collagen and elastin are fibrous proteins that provide structure and elasticity to connective tissues in the body. Collagen is abundant in skin, bone, tendons and cartilage. It forms strong fibers or networks through a triple helix structure. Elastin provides elasticity to tissues like lungs and blood vessels through a rubber-like polymer. Defects in these proteins can cause diseases like brittle bone disease or emphysema.
Collagen is the most abundant protein in mammals and forms the main fibrous component of connective tissues like skin, bone and cartilage. There are many types of collagen that vary in structure and function. Collagen provides strength, support and elasticity to tissues. It is synthesized through a complex process involving post-translational modifications. Collagen in the periodontium includes types I, III, IV, V, VI and XII which provide structure and allow for adaptation to forces. The periodontal ligament has the most rapid collagen turnover of tissues in the body to enable response to occlusion forces.
Collagen is the predominant extracellular matrix component of the periodontium. It is composed of fibrous proteins that form triple helical structures. There are many types of collagen that have been identified, with types I, III, V, and XII being present in the periodontium. Type I collagen is the most abundant and provides structural support and tensile strength to tissues like the periodontal ligament that experience mechanical forces.
The gingival connective tissue consists of collagen fibers, fibroblasts, macrophages, mast cells, and other cells within a ground substance. Collagen types I and III are predominant and provide strength and flexibility. Fibroblasts synthesize collagen and other proteins that make up the extracellular matrix. Mast cells, macrophages, and other immune cells are also present and help defend against pathogens. The connective tissue provides structure, nutrition, and immune function to support the overlying epithelium.
The extracellular matrix (ECM) is an organized network of extracellular materials that surrounds cells. One type of ECM is the basement membrane, a thin sheet that underlies epithelial tissues. The ECM is composed of collagen, elastin, proteoglycans, and structural glycoproteins. Collagen is the most abundant protein in the ECM and forms fibrils that provide structural support and determine the shape of tissues. Collagen molecules assemble into fibrils outside of cells through a process involving post-translational modifications.
The extracellular matrix (ECM) is an organized network of extracellular materials that surrounds cells. One type of ECM is the basement membrane, a thin sheet that underlies epithelial tissues. The ECM is composed of collagen, elastin, proteoglycans, and structural glycoproteins. Collagen is the most abundant protein in the ECM and forms fibrils that provide structural support and determine the shape of tissues. Collagen molecules assemble into fibrils outside of cells through a process involving post-translational modifications.
Collagen and elastin are fibrous proteins found in the extracellular matrix that provide structure. Collagen is the most abundant protein in the body and forms rope-like triple helices from three polypeptide chains. There are over 25 types of collagen that form fibrils, networks, or are associated with fibrils. Collagen synthesis involves post-translational modifications before assembly into fibers and crosslinking outside cells. Abnormalities in collagen synthesis and structure can cause disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta.
This document discusses collagen fibers. It begins by introducing collagen as the main structural protein in connective tissues, making up 25-35% of body protein. Collagen forms elongated fibrils found in tissues like skin, tendons, and bones. It then describes the triple helix structure of collagen and types I-III that form fibrils and networks. Type I collagen comprises many supporting tissues, while type II is found in cartilage. The document also notes medical uses of collagen in skin grafts and cosmetics, as well as genetic diseases associated with collagen deficiencies.
The document discusses the extracellular matrix (ECM), which was once considered an inert scaffold but is now recognized as a complex, interactive network that regulates cell gene expression. It describes the various components that make up the ECM, including collagens, elastin, fibrillin, fibronectin, and laminins. It also discusses the functions of the ECM, such as providing mechanical support and controlling cell proliferation, and describes some clinical correlations regarding genetic defects in collagen.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Fibrous proteins collagen, elastin, and keratin have structural functions.
Collagen forms rope-like triple helices that assemble into strong fibrils in connective tissues. Variations in collagen's alpha chains result in over 25 types with different properties. Defects in collagen synthesis can cause collagenopathies like osteogenesis imperfecta.
Elastin also forms fibrils but has rubber-like properties, being able to stretch and recoil through crosslinking.
In contrast, fibrous proteins form regular structures while globular proteins rely on complex folding interactions.
Fibrous proteins like collagen and elastin provide structural functions. Collagen is abundant in skin, tendons, and the cornea. It forms fibrils with a characteristic triple helix structure. Variations in collagen types are due to differences in their alpha chain sequences. Defects in collagen synthesis can cause connective tissue disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta.
This document provides an overview of collagen, including its structure, synthesis, types found in the body, roles in different tissues like the periodontium and tooth structures, degradation and remodeling, and how it is altered in conditions like inflammation, aging and diseases. It discusses 21 types of collagen and their functions, as well as enzymes involved in collagen degradation. Diseases associated with inherited and acquired collagen issues are also mentioned.
Collagen is the main structural component of the periodontium, constituting around 90% of the organic matrix. It provides tensile strength. There are several types of collagen in the periodontium, with Type I being the most abundant. Collagen is composed of triple helical protein chains and contains high amounts of proline, hydroxyproline and glycine. It undergoes post-translational modifications and cross-linking to provide strength. Collagen fibers are arranged in bundles and insert into cementum and bone via Sharpey's fibers. Elastic fibers also contribute to the periodontium's ability to withstand forces.
Collagen is the main fibrous component of tissues like skin, bone, tendon, cartilage and the periodontium. It comprises around 25% of total protein mass in mammals. Six collagen types have been detected in the periodontium, with Type I being the most abundant. Collagen provides structural support through its fibrillar network and ability to withstand mechanical forces. Synthesis occurs through gene expression and post-translational modification of procollagen. Regulation of collagen breakdown is also important for tissue remodeling. Periodontal diseases involve an imbalance of collagen synthesis and degradation.
This document discusses the biochemistry of collagen. It begins by outlining the objectives which are to describe the structure, distribution, functions, biosynthesis and degradation of collagen as well as diseases related to collagen. It then provides details on the various levels of collagen's structure including its amino acid sequence and triple helical formation. The document also describes the intracellular and extracellular stages of collagen biosynthesis and crosslinking. Finally, it discusses diseases that can result from defects in collagen synthesis, mentioning Ehlers-Danlos syndrome and osteogenesis imperfecta as examples of collagen diseases.
Collagen is the main structural protein in the extracellular matrix and provides strength and structure to tissues. It forms fibrils through a hierarchical assembly of tropocollagen triple helices. Genetic defects in collagen synthesis can result in disorders like Ehlers-Danlos syndrome, which is characterized by overly flexible joints and stretchy skin, or osteogenesis imperfecta, where bones are brittle and fracture easily. Collagen biosynthesis involves post-translational modifications in the endoplasmic reticulum like hydroxylation before collagen fibrils are formed and crosslinked outside the cell.
Chemical composition of cartilage I course.pdfSriRam071
Cartilage is composed of chondrocytes and an extracellular matrix containing collagen and proteoglycans such as aggrecan. There are three main types of cartilage - hyaline, elastic, and fibrocartilage - which differ in their collagen composition. Cyclooxygenase enzymes (COX) catalyze the formation of prostanoids like prostaglandins involved in pain and inflammation. COX1 is constitutively expressed while COX2 is induced during inflammation, making COX2 inhibition an effective strategy for reducing joint inflammation in arthritis.
The document discusses collagen, the most abundant protein in the human body. It describes collagen's structure as a triple helix formed from three polypeptide chains. Collagen provides structure and strength, and is a major component of skin, tendons, and other connective tissues. The document outlines the different types of collagen and classifies them based on their structure and function. It also discusses collagen biosynthesis and abnormalities that can arise from genetic defects in collagen genes and processing enzymes.
Biochemistry of musculoskeletal system. biochemistry of MSS prepared by Fikad...fikaduseyoum1
biochemistry of MSS prepared by Fikadu Seyoum Tola. This ppt essentially discuss about collegen biosnthesis, defect and muscle energy metabolism with its regulations.
Collagen is most abundant protein in mammals, the main fibrous component of skin, bone, tendon and cartilage.
Collagen comprises one- third of the total protein, accounts for three-quarters of the dry weight of skin, and is the most prevalent component of the extracellular matrix.
The collagen family consists of 28 members and these are classified by Roman numbers on the basis of their chronology of discovery.
Collagen is a fibrous protein found in connective tissues. There are over 25 types of collagen that are composed of chains of amino acids. Collagen contains high amounts of proline and glycine which allow it to form its characteristic triple helix structure. Mutations or deficiencies in collagen can lead to diseases like scurvy, Ehlers-Danlos syndrome, and osteogenesis imperfecta, which are characterized by fragile bones and joints.
The cell wall forms immediately after cell division through the action of the endoplasmic reticulum, Golgi bodies, and microtubules. It is composed primarily of cellulose, which is made of beta-D glucose molecules linked together. Cellulose macrofibrils are loosely arranged in the cell wall. The glycocalyx is a carbohydrate-rich coating outside the cell membrane made of glycoproteins and glycolipids that provides protection, acts as a barrier, and enables cell recognition and signaling. It is 500-2000nm thick and helps regulate processes like adhesion, protection, permeability, transplantation compatibility and inflammation.
This document provides information on epithelial tissue and cell junctions. It discusses the general features of epithelial tissue, including that epithelial cells are closely packed with many cell junctions. It also describes the different types of epithelial tissue (simple vs stratified), the cell shapes (squamous, cuboidal, columnar), and locations in the body. The document further explains the structure and functions of the basement membrane and cell junctions, including occluding junctions, anchoring junctions, and communicating junctions. Key cellular adhesion molecules and proteins involved in different junction types are also outlined.
This document provides information about lymph nodes and the lymphatic system. It discusses the anatomy, embryology, histology, and physiology of lymph nodes and lymphatic drainage. Key points include:
- Lymph nodes act as filters for the lymphatic system and help fight infection. They are located along lymphatic vessels.
- The primary lymphoid organs are the bone marrow and thymus, where lymphocytes develop. Secondary lymphoid organs include the spleen, lymph nodes, tonsils, and skin.
- Lymph nodes have an outer cortex and inner medulla. Lymph enters through afferent vessels and exits through efferent vessels. High endothelial venules are found
This document discusses collagen fibers. It begins by introducing collagen as the main structural protein in connective tissues, making up 25-35% of body protein. Collagen forms elongated fibrils found in tissues like skin, tendons, and bones. It then describes the triple helix structure of collagen and types I-III that form fibrils and networks. Type I collagen comprises many supporting tissues, while type II is found in cartilage. The document also notes medical uses of collagen in skin grafts and cosmetics, as well as genetic diseases associated with collagen deficiencies.
The document discusses the extracellular matrix (ECM), which was once considered an inert scaffold but is now recognized as a complex, interactive network that regulates cell gene expression. It describes the various components that make up the ECM, including collagens, elastin, fibrillin, fibronectin, and laminins. It also discusses the functions of the ECM, such as providing mechanical support and controlling cell proliferation, and describes some clinical correlations regarding genetic defects in collagen.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Fibrous proteins collagen, elastin, and keratin have structural functions.
Collagen forms rope-like triple helices that assemble into strong fibrils in connective tissues. Variations in collagen's alpha chains result in over 25 types with different properties. Defects in collagen synthesis can cause collagenopathies like osteogenesis imperfecta.
Elastin also forms fibrils but has rubber-like properties, being able to stretch and recoil through crosslinking.
In contrast, fibrous proteins form regular structures while globular proteins rely on complex folding interactions.
Fibrous proteins like collagen and elastin provide structural functions. Collagen is abundant in skin, tendons, and the cornea. It forms fibrils with a characteristic triple helix structure. Variations in collagen types are due to differences in their alpha chain sequences. Defects in collagen synthesis can cause connective tissue disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta.
This document provides an overview of collagen, including its structure, synthesis, types found in the body, roles in different tissues like the periodontium and tooth structures, degradation and remodeling, and how it is altered in conditions like inflammation, aging and diseases. It discusses 21 types of collagen and their functions, as well as enzymes involved in collagen degradation. Diseases associated with inherited and acquired collagen issues are also mentioned.
Collagen is the main structural component of the periodontium, constituting around 90% of the organic matrix. It provides tensile strength. There are several types of collagen in the periodontium, with Type I being the most abundant. Collagen is composed of triple helical protein chains and contains high amounts of proline, hydroxyproline and glycine. It undergoes post-translational modifications and cross-linking to provide strength. Collagen fibers are arranged in bundles and insert into cementum and bone via Sharpey's fibers. Elastic fibers also contribute to the periodontium's ability to withstand forces.
Collagen is the main fibrous component of tissues like skin, bone, tendon, cartilage and the periodontium. It comprises around 25% of total protein mass in mammals. Six collagen types have been detected in the periodontium, with Type I being the most abundant. Collagen provides structural support through its fibrillar network and ability to withstand mechanical forces. Synthesis occurs through gene expression and post-translational modification of procollagen. Regulation of collagen breakdown is also important for tissue remodeling. Periodontal diseases involve an imbalance of collagen synthesis and degradation.
This document discusses the biochemistry of collagen. It begins by outlining the objectives which are to describe the structure, distribution, functions, biosynthesis and degradation of collagen as well as diseases related to collagen. It then provides details on the various levels of collagen's structure including its amino acid sequence and triple helical formation. The document also describes the intracellular and extracellular stages of collagen biosynthesis and crosslinking. Finally, it discusses diseases that can result from defects in collagen synthesis, mentioning Ehlers-Danlos syndrome and osteogenesis imperfecta as examples of collagen diseases.
Collagen is the main structural protein in the extracellular matrix and provides strength and structure to tissues. It forms fibrils through a hierarchical assembly of tropocollagen triple helices. Genetic defects in collagen synthesis can result in disorders like Ehlers-Danlos syndrome, which is characterized by overly flexible joints and stretchy skin, or osteogenesis imperfecta, where bones are brittle and fracture easily. Collagen biosynthesis involves post-translational modifications in the endoplasmic reticulum like hydroxylation before collagen fibrils are formed and crosslinked outside the cell.
Chemical composition of cartilage I course.pdfSriRam071
Cartilage is composed of chondrocytes and an extracellular matrix containing collagen and proteoglycans such as aggrecan. There are three main types of cartilage - hyaline, elastic, and fibrocartilage - which differ in their collagen composition. Cyclooxygenase enzymes (COX) catalyze the formation of prostanoids like prostaglandins involved in pain and inflammation. COX1 is constitutively expressed while COX2 is induced during inflammation, making COX2 inhibition an effective strategy for reducing joint inflammation in arthritis.
The document discusses collagen, the most abundant protein in the human body. It describes collagen's structure as a triple helix formed from three polypeptide chains. Collagen provides structure and strength, and is a major component of skin, tendons, and other connective tissues. The document outlines the different types of collagen and classifies them based on their structure and function. It also discusses collagen biosynthesis and abnormalities that can arise from genetic defects in collagen genes and processing enzymes.
Biochemistry of musculoskeletal system. biochemistry of MSS prepared by Fikad...fikaduseyoum1
biochemistry of MSS prepared by Fikadu Seyoum Tola. This ppt essentially discuss about collegen biosnthesis, defect and muscle energy metabolism with its regulations.
Collagen is most abundant protein in mammals, the main fibrous component of skin, bone, tendon and cartilage.
Collagen comprises one- third of the total protein, accounts for three-quarters of the dry weight of skin, and is the most prevalent component of the extracellular matrix.
The collagen family consists of 28 members and these are classified by Roman numbers on the basis of their chronology of discovery.
Collagen is a fibrous protein found in connective tissues. There are over 25 types of collagen that are composed of chains of amino acids. Collagen contains high amounts of proline and glycine which allow it to form its characteristic triple helix structure. Mutations or deficiencies in collagen can lead to diseases like scurvy, Ehlers-Danlos syndrome, and osteogenesis imperfecta, which are characterized by fragile bones and joints.
The cell wall forms immediately after cell division through the action of the endoplasmic reticulum, Golgi bodies, and microtubules. It is composed primarily of cellulose, which is made of beta-D glucose molecules linked together. Cellulose macrofibrils are loosely arranged in the cell wall. The glycocalyx is a carbohydrate-rich coating outside the cell membrane made of glycoproteins and glycolipids that provides protection, acts as a barrier, and enables cell recognition and signaling. It is 500-2000nm thick and helps regulate processes like adhesion, protection, permeability, transplantation compatibility and inflammation.
This document provides information on epithelial tissue and cell junctions. It discusses the general features of epithelial tissue, including that epithelial cells are closely packed with many cell junctions. It also describes the different types of epithelial tissue (simple vs stratified), the cell shapes (squamous, cuboidal, columnar), and locations in the body. The document further explains the structure and functions of the basement membrane and cell junctions, including occluding junctions, anchoring junctions, and communicating junctions. Key cellular adhesion molecules and proteins involved in different junction types are also outlined.
This document provides information about lymph nodes and the lymphatic system. It discusses the anatomy, embryology, histology, and physiology of lymph nodes and lymphatic drainage. Key points include:
- Lymph nodes act as filters for the lymphatic system and help fight infection. They are located along lymphatic vessels.
- The primary lymphoid organs are the bone marrow and thymus, where lymphocytes develop. Secondary lymphoid organs include the spleen, lymph nodes, tonsils, and skin.
- Lymph nodes have an outer cortex and inner medulla. Lymph enters through afferent vessels and exits through efferent vessels. High endothelial venules are found
Dr. Sonam Rani presented on the topic of cementum to several professors and colleagues. Cementum is a calcified tissue that covers tooth roots and provides attachment for periodontal ligaments. It comes in several types classified based on cellularity, presence of fibers, and origin. Cementum is formed by cementoblasts and cementocytes and plays an important role in tooth adaptation and repair. Systemic conditions like Paget's disease and cleidocranial dysplasia can affect cementum formation and structure.
This document provides an overview of pain, including its definition, classification, theories, transmission and modulation pathways, assessment, and management approaches. It begins with definitions of pain from Dorland's Medical Dictionary and Monheim. It then classifies pain according to intensity, temporal relationship, qualities, onset, and localization. Theories of pain discussed include specificity, pattern, and gate control theories. It describes the dual nature of pain and the transduction, transmission, modulation, and perception of pain. It discusses referred pain and neuropathic pain. The document concludes by covering pain assessment tools and pharmacological and non-pharmacological management strategies.
COMMON SEMINAR STERILISATION, INFECTION CONTROL AND HOSPITAL MANAGEMENT.pptxmalti19
This document discusses sterilization, infection control, and hospital management in dentistry. It defines key terms like sterilization, disinfection, and asepsis. It then describes various methods of sterilization including physical methods like heat and radiation, and chemical methods like alcohols, phenols, aldehydes, halogens, and gases. The document provides details on specific sterilization techniques and protocols for sterilizing dental instruments used in different specialties. It emphasizes the importance of proper sterilization to prevent disease transmission between patients.
This document summarizes key concepts in immunology as they relate to periodontal disease. It discusses the epithelial barrier and pattern recognition receptors that detect pathogens. Inflammatory mediators recruit immune cells through chemotaxis. T lymphocytes develop and differentiate into subsets like Th1, Th2, Th17 that activate different immune responses. B cells produce antibodies through somatic hypermutation. Regulatory T cells control self-tolerance. The adaptive response becomes antigen-specific and develops memory. Dendritic cells present antigens to activate T cells. An imbalance in T cell subsets can lead to tissue destruction in periodontal disease.
Thrombosis, embolism, and infarction are related pathological processes involving blood clots. Thrombosis is the formation of a blood clot within a blood vessel, while embolism occurs when a piece of a clot breaks off and travels to another location. Infarction results from obstruction of blood flow by a clot, causing tissue death. The document discusses the mechanisms, types, features, and progression of thrombosis, embolism, and infarction. It also covers related topics like Virchow's triad, hypercoagulable states, fat embolism, and amniotic fluid embolism.
Thrombosis, embolism, and infarction are related pathological processes involving blood clots. Thrombosis is the formation of a blood clot within a blood vessel, while embolism occurs when a piece of a clot breaks off and travels to another location. Infarction results from obstruction of blood flow by a clot, causing tissue death. The document discusses the mechanisms, classifications, and morphological features of thrombosis, embolism, and infarction. It also covers related topics like Virchow's triad, hypercoagulable states, and the development and types of infarcts over time.
Immune responses in periodontal disease final.pptxmalti19
This document discusses the immune responses involved in periodontal disease. It begins by defining periodontitis as an infectious disease caused by anaerobic bacteria. Both bacteria and a susceptible host are required to cause disease. It then describes the pathogenesis which involves environmental and genetic risk factors interacting with the microbial challenge to activate the host immune response, resulting in inflammation and bone/tissue destruction. The document discusses the types of immunity, including innate and adaptive immunity. It covers topics such as dendritic cells, T-cell and B-cell roles, the roles of cytokines and RANKL in linking the immune response to bone loss, and hypotheses about the roles of the Th1 and Th2 responses in periodontitis.
This document provides an overview of antibiotics used in periodontics. It begins with an introduction to antibiotics and their historical background. It then covers classification of antimicrobial agents based on chemical structure, mechanism of action, organisms targeted, and spectrum of activity. Guidelines for antibiotic use in periodontal diseases are presented, along with the diseases where antibiotics can be used. Commonly used antibiotics like tetracycline, doxycycline, metronidazole, penicillin, and amoxicillin-clavulanate are described in detail. The document concludes with a reference to research on systemic antibiotic use in periodontics.
This document discusses evidence-based periodontology and decision making. It defines evidence-based periodontology as applying evidence-based healthcare to periodontology by integrating the best available evidence with clinical practice. The document outlines the steps of evidence-based periodontology, including asking questions using the PICO format, searching for and appraising evidence from systematic reviews and clinical practice guidelines, and applying the evidence to clinical decisions. It also discusses tools for critically assessing evidence, such as considering different levels of evidence and ensuring temporality between causes and effects.
Calcium and Phosphorous metabolism 23-03-23.pptxmalti19
Calcium and phosphorus metabolism is tightly regulated by vitamin D, parathyroid hormone, and calcitonin. Calcium is crucial for bone development, nerve function, and other processes. The recommended daily intake is 800 mg for adults. Dietary sources include dairy products, leafy greens, and fish. Absorption occurs in the small intestine and is influenced by vitamin D, PTH, and other factors. Hormonal signals work to maintain calcium levels within a narrow range. Disorders like rickets and osteomalacia can result from vitamin D deficiency. Precise regulation is needed to prevent hypercalcemia or hypocalcemia.
The document summarizes the anatomy and function of the muscles of mastication. It describes the three main muscles - masseter, temporalis, and medial and lateral pterygoid. It discusses their embryological development, nerve supply, actions, and clinical evaluation. The masseter muscle is palpated to assess for hypertrophy. Orthodontic treatment can impact the thickness of the muscles. The medial pterygoid muscle is also described in more detail, including its nerve supply by the mandibular nerve, blood supply, actions, and clinical examination.
The facial nerve emerges from the brainstem between the pons and medulla. It has motor, sensory, and parasympathetic secretomotor components. During embryonic development, it arises from the second branchial arch. The nerve passes through the internal acoustic meatus and facial canal within the temporal bone. It gives off several branches within the facial canal before exiting at the stylomastoid foramen. Its main branches in the face include the temporal, zygomatic, buccal, marginal mandibular, and cervical branches which innervate the muscles of facial expression.
1) PRP and PRF are platelet concentrates that provide growth factors that may enhance tissue regeneration.
2) Studies have shown PRP and PRF can increase the release of growth factors like PDGF, TGF-β1, and VEGF compared to control groups.
3) However, the evidence on whether PRP and PRF improve bone regeneration outcomes is mixed. Some studies found benefits for parameters like new bone formation and defect fill, while other studies found no additional benefits compared to control treatments.
This document discusses chlorhexidine, a commonly used chemical plaque control agent. It provides details on the history, chemistry, forms, mechanisms of action, products, clinical uses, toxicity and side effects of chlorhexidine. Chlorhexidine is a bisbiguanide antiseptic that is highly effective at inhibiting plaque formation and controlling gingivitis when used as a mouthrinse. It has a wide range of clinical applications and is generally well-tolerated, though long-term use can cause staining and changes to taste sensation in some individuals.
Oral hygiene and overall health
Department of Periodontology and oral Implantology
The document discusses the importance of oral hygiene for preventing dental diseases and maintaining overall health. It notes that over 3.5 billion people suffer from oral diseases according to the WHO, but many can be prevented through proper oral hygiene. Maintaining oral hygiene includes brushing teeth twice daily, flossing, cleaning the tongue, and visiting the dentist regularly. Poor oral hygiene can lead to dental caries, gum disease, and systemic issues like diabetes and heart disease.
Reducing fracture risk with Calcium and Vitamin D
Osteoporotic fractures are a major health problem that most commonly affect the spine and hip. Low calcium intake and vitamin D deficiency increase fracture risk by reducing bone mineral density and strength. Clinical trials show that calcium and vitamin D supplementation can reduce fracture risk, especially when vitamin D doses reach 800 IU daily and calcium intake reaches 1000-1200 mg. For older individuals, supplementation is most effective for those at high risk of deficiency living in nursing homes or with low dairy intake.
Antibiotics in the management of chronic periodontitis.pptmalti19
This document summarizes evidence on the use of adjunctive antibiotics for chronic periodontitis. A systematic review of 25 studies found some additional benefits of antibiotics in deep pockets, including 0.2-0.6 mm more attachment gain and 0.2-0.8 mm more probing depth reduction. However, the clinical relevance is uncertain given limitations in defining chronic periodontitis and its microbiota. Overall, current studies have not conclusively established benefits of adjunctive antibiotics, so they cannot be routinely indicated as adjuncts for chronic periodontitis.
The document discusses immediate dentures, which are complete or partial dentures fabricated immediately after tooth extraction. It describes the differences between conventional (classic) immediate dentures and interim (transitional) immediate dentures. Conventional immediate dentures are intended as the long-term prosthesis and are made when only anterior teeth remain. Interim immediate dentures are short-term and are made when posterior teeth remain, requiring only one surgical visit. The document outlines the procedures, indications, contraindications, advantages and disadvantages of both types of immediate dentures.
This presentation was provided by Rebecca Benner, Ph.D., of the American Society of Anesthesiologists, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
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Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
2. • INTRODUCTION
• STRUCTURAL FEATURES
• BIOSYNTHESIS
• TYPES AND TISSUE DISTRIBUTION
• DEGRADATION AND REMODELLING OF COLLAGEN
• FUNCTIONS OF COLLAGEN
• DISEASES/CLINICAL IMPLICATIONS
• CONCLUSION
3. - Cells are the basic units of life. Most mammalian cells are located in tissues
where they are surrounded by a complex extracellular matrix(ECM), often
referred to as the connective tissue .
- The extracellular matrix contains three major class of biologic molecules.
• Structural proteins such as collagen and elastin.
• Certain specialized proteins such as fibrillin,fibronectin and laminin.
• Proteoglycans which consists of glycosaminoglycans,formerly called as
mucopolysaccharides.
4. - The supramolecular arrangement of fibrillar elements, microfibrillar
networks as well as soluble proteins, glycoproteins and a wide range
of other molecules define the biophysical characteristics.
- The primary function of extracellular matrix is to endow tissues with
their specific mechanical and biochemical properties. Resident cells
are responsible for its synthesis and maintenance, but the extracellular
matrix, in turn, has also an impact on cellular functions.
- An additional influence of the extracellular matrix on morphogenesis
and cellular metabolism can be ascribed to the storage and release of
growth factors which is modulated by their binding to specific matrix
components
5. - The most abundant proteins in the extracellular matrix are members of
the collagen family.
- Collagens were once considered to be a group of proteins with a
characteristic molecular structure with their fibrillar structures
contributing to the extracellular scaffolding.
- Thus, collagens are the major structural element of all connective
tissues and are also found in the interstitial tissue of virtually all
parenchymal organs, where they contribute to the stability of tissues
and organs and maintain their structural integrity.
6. • Collagen – derived from the greek word – kolla(glue) and gene.
• Triple helical structure : Characteristic triple helix of three polypeptide
chains and all members of the collagen family form these supramolecular
structures in the extracellular matrix although their size, function and tissue
distribution vary considerably.
• Each of the three a-chains within the molecule forms an extended left-
handed helix with a pitch of 18 amino acids per turn. The α chains are left
handed helices that wrap around each other into a right handed rope like
triple helical rod.
7. structure
• 1.Presence of triple helical structure formed by alpha chains(RICH
,CRICK AND NORTH-1955)
• 2.Glycine occupies every third position in amino acid sequence (Gly –
X – Y)
• 3.Contains unique amino acids hydroxylysine and hydroxyproline.
• 4.Collagen is stabilized by lysine derived intra and intermolecular
cross-links
8.
9.
10. α-Helix
• α-Helix is the most common spiral
structure of protein
• The salient feature: The α-Helix is a
tightly packed coiled structure with
amino acid side chains extending
outward from the central axis.
• The α-Helix - stabilized by extensive
hydrogen bonding
11. BIOSYNTHESIS
• Involved in tissue differentiation, growth and remodeling
• Young tissue has high rate of collagen synthesis
• As the tissues matures in adults, synthesis continues as a part of
normal tissue turnover
• Highest rate of collagen turnover are observed in weight bearing
bones, lungs and periodontal tissues
• Collagen synthesis is elevated under conditions requiring remodeling
and replacement of tissues and during tissue repair
• Elevated rates in pathological conditions such as fibrosis in lungs and
liver
12. Collagen Synthesizing Cells
• Synthesized by cells of mesodermal origin, collectively referred to as fibroblast
• In highly differentiated state these fibroblast acquire characters especially suited
to the chemistry of the tissues
• Chondroblast in cartilage
• Odontoblast in teeth
• Osteoblast in bone
13. • Collagen synthesizing cells
contains extensive RER and well
developed Golgi apparatus
• Synthesized in RER, passed into
Golgi and secreted into
extracellular space.
14. STEPS
Intracellular
synthesis of collagen mRNA
Peptide Synthesis
Hydroxylation of proline and lysine
glycosylation of hydroxylysine
Disulfide bond
Secretion of Procollagen
(Triple helical)
Req Vit C
20. TYPES AND TISSUE DISTRIBUTION
• So far, 28 genetically distinct collagen types have been described.
Based on their structure and supramolecular organization, they can
be grouped into :
- fibril-forming collagens
- fibril-associated collagens (FACIT)
- network- forming collagens
- anchoring fibrils
- transmembrane collagens
- basement membrane collagens and others with unique functions.
21.
22.
23. THE FIBRIL FORMING COLLAGENS
• Collagen types I, II, III, V and XI.
• Characterized by their ability to assemble into highly orientated
supramolecular aggregates with a characteristic suprastructure, the typical
quarter-staggered fibril-array with diameters between 25 and 400 nm.
• In the electron microscope, the fibrils are defined by a characteristic
banding pattern with a periodicity of about 70 nm (called the D-period)
based on a staggered arrangement of individual collagen monomers.
24. - The triple helix is usually formed as a heterotrimer by two identical
a1(I)-chains and one a2(I)-chain. The triple helical fibres are, in vivo,
mostly incorporated into composite containing either type III collagen
(in skin and reticular fibres) or type V collagen (in bone, tendon,
cornea)
• Type I collagen provides tensile stiffness and in bone, it defines
considerable biomechanical properties concerning load bearing, tensile
strength, and torsional stiffness in particular after calcification.
25.
26. • Type II collagen
• The characteristic and predominant component of hyaline cartilage.
• The triple helix of type II collagen is composed of three a1(II)-chains
forming a homotrimeric molecule similar in size and biomechanical
properties to that of type I collagen.
• Collagen fibrils in cartilage represent heterofibrils containing in addition to
the dominant collagen II, also types XI and IX collagens which are
supposed to limit the fibril diameter to about 15–50 nm as well as other
non-collagenous proteins.
27. • Type III collagen
• Type III collagen is a homotrimer of three a1(III)-chains and is widely
distributed in collagen I containing tissues with the exception of bone.
• It is an important component of reticular fibres in the interstitial tissue
of the lungs, liver, dermis, spleen, and vessels.
• This homotrimeric molecule also often contributes to mixed fibrils
with type I collagen and is also abundant in elastic tissues.
28. • Types V and XI collagens are formed as heterotrimers of three different
a-chains (a1, a2, a3).
• the a3-chain of type XI collagen is encoded by the same gene as the a1-
chain of type II collagen and only the extent of glycosylation and
hydroxylation differs from a1(II).
• Types V and XI collagens form a subfamily within fibril-forming
collagens,(a combination between different types V and XI chains appears
to exist in various tissues) though they share similar biochemical properties
and functions with other members of this family.
29. Collagen types IX, XII, and XIV—The FACIT collagens
• The collagen types IX, XII, XIV, XVI, XIX, and XX belong to the so-called Fibril-
Associated Collagens with Interrupted Triple helices (FACIT collagens).
• The structures of these collagens are characterized by ‘‘collagenous domains’’ interrupted
by short non-helical domains and the trimeric molecules are associated with the surfaces
of various fibrils.
• presumably play a role in regulating the diameter of collagen fibrils.
• Collagen type IX co-distributes with type II collagen in cartilage and the vitreous body .
The heterotrimeric molecule consists of three different achains (a1(IX), a2(IX), and
a3(IX)) forming three triple helical segments flanked by four globular domains (NC1–
NC4).
30. • Type IX collagen molecules are located periodically along the
surface of type II collagen fibrils in antiparallel direction. This
interaction is stabilized by covalent lysine-derived cross-links to the
N-telopeptide of type II collagen.
• A hinge region in the NC3 domain provides flexibility in the molecule
and allows the large and highly cationic globular N-terminal domain to
reach out from the fibril where it presumably interacts with
proteoglycans or other matrix components. Additionally, collagen type
XVI is found in hyaline cartilage and skin and is associated with a
subset of the collagen ‘‘type II fibers’’ (Graessel).
31. • Types XII and type XIV collagens are similar in structure and
share sequence homologies to type IX collagen. Both molecules
associate or colocalize with type I collagen in skin, perichondrium,
periosteum,tendons, lung, liver, placenta, and vessel walls.
32. • Collagen type VI—a microfibrillar collagen
• Type VI collagen is an heterotrimer of three different a-chains (a1, a2, a3)
with short triple helical domains and rather extended globular termini. This
is in particular true for the a3-chain which is nearly as twice as long as the
other chains due to a large N- and C-terminal globular domains.
• However, these extended domains are subject not only to alternative
splicing, but also to extensive posttranslational processing, both within and
outside the cell. The primary fibrils assemble already inside the cell to
antiparallel, overlapping dimers, which then align in a parallel manner to
form tetramers.
33.
34. - Type VII collagen is the predominant component of the anchoring fibrils of basement
membranes.
- Secreted in a soluble form by basal epithelial cells
- Composed of a central helical portion with a globular domain at the C-terminal and a
small nonhelical domain at the N-terminal.
- These triple helical molecules align at the C-terminus as antiparallel dimers of
approximately 450 nM each in length. One end of the molecule becomes embedded in the
lamina densa of the basement membrane, where it interacts with type IV collagen, and the
other end attaches to anchoring plaques.
- Type VII collagen has been localized in the basement membrane of gingival oral
epithelium
35. • Types I and V collagen - the structural backbone of bone
• Types II and XI collagens - the fibrillar matrix of articular cartilage. Their torsional stability and
tensile strength lead to the stability and integrity of these tissues.
• Type IV collagens -basement membranes.
• Type VI collagen - highly disulfide cross-linked and contributes to a network of beaded filaments
interwoven with other collagen fibrils.
• Fibril-associated collagens with interrupted triple helices (FACIT) such as types IX, XII, and XIV
collagens - presumably play a role in regulating the diameter of collagen fibrils.
• Types VIII and X collagens - form hexagonal networks while others (XIII and XVII) even span
cell membranes.
36. GINGIVA
• Type I collagen is the main collagen species in all layers of gingival connective tissues.
• The collagen fibers are arranged in two patterns of organization, one consisting of large,
dense bundles of thick fibers(Type I collagen is preferentially organized into denser fibrils
in the lamina propria.)
• and the other, a loose pattern of short thin fibers mixed with a fine reticular network.
These fibers contain both type I and III collagens.
• Although it is not restricted to any particular region, type III collagen appears to be
preferentially localized as thinner fibers in a reticular pattern near the basement
membrane at the epithelial junction. Type III collagen has a more diffuse pattern in lamina
propria.
37. PERIODONTAL LIGAMENT
• The fibroblast is the predominant cell of the PDL.They are regularly distributed throughout the
ligament and are oriented with their long axis parallel to the direction of collagen fibrils.
• They have the ability to synthesize and shape of proteins of the ECM in which collagen fibrils
form bundles that insert into the tooth as Sharpey’s fibres.
• The collagen of periodontal ligament is Type I (80%), type III (20%) with lesser amounts of Type
IV, V, VI & XII also present.
• The collagen fiber bundles in the ligament and the fibers of Sharpey are mainly composed of
interstitial collagens I and III, which form banded fibrils.
38. • Type III collagen is more fibrillar and extensible than type I and may be
important in maintaining the integrity of the ligament during the small
vertical and horizontal movements which occur during chewing.
• The principal fibers are composed mainly of collagen type I, whereas
reticular fibers are composed of collagen type III. Collagen type III
generally co-distributes with collagen type I to form mixed fibrils of
infinitely varying proportions, a higher proportion of collagen type III is
present in fetal tissue.
• Collagen type IV is a short chain molecule that has only recently been
located in the periodontal ligament.
39. • Type III collagen is more fibrillar and extensible than type I and may be
important in maintaining the integrity of the ligament during the small
vertical and horizontal movements which occur during chewing.
• The principal fibers are composed mainly of collagen type I, whereas
reticular fibers are composed of collagen type III. Collagen type III
generally co-distributes with collagen type I to form mixed fibrils of
infinitely varying proportions, a higher proportion of collagen type III is
present in fetal tissue.
• Collagen type IV is a short chain molecule that has only recently been
located in the periodontal ligament.
40. • Collagen VI is a microfibrillar component, not directly associated with the major
banded collagen fibrils (but with the oxytalan fiber system),collagen XII belongs
to the fibril-associated collagens with interrupted triple helices that contribute to
the construction of the three-dimensional fibril arrangement.
• Temporal and spatial expressions of collagens I and XII in the remodeling
periodontal ligament during experimental tooth movement suggest that collagen
XII is closely associated with regeneration of periodontal ligament function.
• Besides collagens, several other proteins occur in the extracellular matrix of the
ligament that may have a relationship with the macromolecular organization.
41. BONE
• Collagen comprises the major (80–90%) organic component in mineralized bone
tissues.
• Type I collagen + type V collagen heterotypic fiber bundles that provide the
basic structural integrity of connective tissues.
• Along with type I and V collagens in alveolar bone, both type III and XII
collagens are also present.
• The type III collagen is present as mixed fibers with type I collagen in Sharpey’s
fibers that insert from the periodontal ligament into the lamellar bone lining the
alveolus to provide a stable connection with the tooth.
42. CEMENTUM
• Cementum is approximately 45 to 50% hydroxyappatite (inorganic) and 50%
collagen and non collagenous matrix proteins (organic).
• Collagen type I is the predominant collagen. It plays a key role in regulating
periodontal tissues during development and regeneration.
• In addition, during early stages of cementogenesis, development and repair, type
III collagen is present in high amounts but is decreased with maturation of this
tissue.
• Also, type XII collagen may assist in maintaining periodontal ligament space
versus continuous formation of cementum. Trace amounts of other collagens,
including type V and type XIV are also found in extracts of mature cementum.
43. COLLAGEN DEGRADATION AND
REMODELLING
• Degradation of collagen and other matrix elements is a key component
of normal tissue remodeling .
• However, extracellular matrix degradation also leads to pathologic
alterations.
• for example it is the major cause of connective tissue destruction in
periodontitis, rheumatoid arthritis and other chronic inflammatory
diseases.
44. • Though several other enzymes are involved in degradation of matrix
components ,collagen degradation is primarily mediated by collagenases.
• These enzymes have specifically evolved to hydrolyze collagens because
the triple helical collagen structure is resistant to most common proteinases.
The collagenases belong to a family of enzymes called Matrix
metalloproteinases (MMPs’).
• They are 13 in number each one having a 21kd catalytic domain that
contains Zn binding site.
45. • Based on their substrate specificity (Woessner et al 1991, Mignatti et al 1996 )
classified them into the following types
- Collagenases
- Gelatinases
- Stromelysins
- Matrilysins
• Three interstitial collagenases capable of degrading native matrix collagen fibrils
have been isolated and described so far.
• All of them cleave α1(I) and α2(I) chains at the glycine 775 – isoleucine 776
bonds respectively
46. • This results in release of cleavage fragments about three quarters and one quarter of the chain’s
original size.
• The released fragments have a lower Tm than the intact collagen molecule at the physiologic
temperature ,therefore become denatured and are subsequently denatured by other proteinases.
Collagenase 1 / MMP-1 / Fibroblast type collagenase
• It is produced by a variety of human epithelial and mesenchymal cells including
keratinocytes,fibroblasts and macrophages.
• It can hydrolyze type I, II, III, VI, VIII and X collagen and gelatin ( Birkedal-Hansen et al
1993).
• It hydrolyzes type III collagen molecules faster when compared to type I.
47. Collagenase 2 / PMN leukocyte collagenase / MMP-8
• It hydrolyzes both type I and type III collagen.It degrades type I faster than
type III collagen.
• It is found only in the specific granules of polymorphonuclear neutrophil cells.
• Gelatinase group of matrix metalloproteinases:
They include
- 72 kd gelatinase A or MMP-2
- 92 kd gelatinase B or MMP-9
48. • Both have a high affinity for gelatin but can also cleave types IV, VII, X and
XI collagens and elastin.
• They cleave the Gly – X peptide bond where X may be
valine,leucine,glutamine or serine.
• Gelatinase B is produced by eosinophils, macrophages, keratinocytes and is
also stored in the polymorphonuclear neutrophil granules.
• Its synthesis is regulated by several inflammatory mediators.
• In contrast gelatinase A synthesis is regulated by TGF-β.
49.
50. FUNCTIONS OF COLLAGEN
• It is the main component of fascia, cartilage, ligaments, tendons, bone
and teeth. It is responsible for skin strength and elasticity, and its
degradation leads to wrinkles that accompany ageing.
• It strengthens blood vessels and plays a role in tissue development
and nutrition.
• It is present in the cornea and lens of the eye in crystalline form
51. • Applications of collagen as a biomaterial
• To repair tissues such as bone, tendon, ligament, skin, vascular and
connective tissues.
• For use as sealant, implant coating, adhesion barrier and tissue
engineering devices.
• Drug delivery applications: to develop scaffolds for delivery of genes,
cell, growth factors, anesthetics, analgesics, antibiotics etc.
• Tissue augmentation: For use in plastic surgery
• For use in collagen coating of grafts.
52. • To enhance blood coagulation and platelet activation
• To enhance durability of allograft tissues
• Can be used for the generation of bone substitutes, wound dressings,
nerve regeneration,
• Artificial skin
• For use as a research tool to study diseases such as diabetes and aging,
and to evaluate drugs
53. • Some of the available Collagen-Based Localised Drug Delivery
Systems
• Collatamp G -Collatamp G is an implantable type-I collagen sponge
impregnated with 2.0 mg/cm2 of gentamicin sulfate. It is approved as
a medicinal drug product in many European countries and is currently
marketed under various brand names. The product is indicated for the
surgical treatment and post-surgical prevention of infection in bone
and soft tissue and has been clinically proven to reduce rates of
infection/reinfection and substantially reduce the average duration of a
hospital stay
54. • INFUSE™ Bone Graft and InductOs™
• Wound healing
• Collagen Stents and Vascular Graft Coatings
55. COLLAGEN MEMBRANES USED IN GUIDED
TISSUE REGENERATION
The use of devices in periodontal regenerative therapy has been
associated with the concept of guided tissue regeneration. The
hypothesis originated by Melcher and established by Karring et al.
suggests that selected cell populations residing in the periodontium
can produce new cementum, alveolar bone and periodontal ligament,
provided that these populations are given the opportunity to occupy a
periodontal wound.
Such opportunity arises when other cell populations, such as epithelial
cells or gingival fibroblasts, which also would invade the wound space
are effectively excluded. This provision to exclude specific tissues
during the healing phase of a periodontal defect wound has generated
an impetus for the development of periodontal devices, commonly
called barriers or membranes, for guided tissue regeneration.
56. • Medical Uses
1.Collagen has been widely used in cosmetic surgery, as a healing aid for burn patients, for
reconstruction of bone and a wide variety of dental, orthopedic and surgical purposes.
2. Collagen sponge is also used in filling bone defects.
3. It is also used as a haemostatic agent and as a wound dressing. Eg. Collatape, collacote,
and collaplug.
4. It is used as a slow drug delivery system. For eg. Phosphorylated collagen used in
delivery of epidermal growth factor and DNA- infused gel of modified collagen for the
delivery of cytokines.
5. Injectable collagen has been used in an attempt to correct distensible acne scars, atrophy
from disease or trauma, postrhinoplasty irregularities, glabellar frown lines, nasolabial folds
and variety of other surface depressions and abnormalities.
6.Collagen is also used as a GTR membrane.
7. It is also sold commercially as a joint mobility supplement
57. ASSOCIATED DISEASES
• OSTEOGENESIS IMPERFECTA:
Defective connective tissue,Characterised by impairment of collagen
maturation
↓collagen synthesis or structurally defective collagen.
• Caused by a mutation in type 1 collagen
• dominant autosomal disorder
• results in weak bones and irregular connective tissue
• some cases can be mild while others can be lethal, mild cases have
lowered levels of collagen type 1 while severe cases have structural
defects in collagen
58. • EHLERS DANLOS SYNDROME (Van meekaran -1682)
Group of connective tissue disorder.
Caused by a defect in the structure,production or processing of collagen or
by a defect in the proteins that interact with collagen.
Hyperextensibility of skin,hypermobility of joints and tissue fragility.
Interference with conversion of procollagen to collagen-↓cross linking-
reduction in tensile strength of the tendons.
Hypoplasia,microdontia,pulp stone, deformed roots,subluxation of TMJ
• Ten different types of this disorder, which lead to deformities in connective
tissue. Some types can be lethal, leading to the rupture of arteries. Each
syndrome is caused by a different mutation, for example type four of this
disorder is caused by a mutation in collagen type 3.
59. • STICKLER SYNDROME: (Gunnar stickler -1965)
• It is a group of genetic disorders affecting connective tissue especially
collagen.
• It is thought to arise due to the mutation of several collagen genes
during fetal development.
Premature osteoarthritis,retinal degeneration,hearing loss and
orofacial abnormalities.
Caused due to the mutation in procollagen for type 2 and 11.
60. • ALPORT SYNDROME
mutation occur on genes of the x –chromosome.
Caused by a defect in type 4 collagen
Renal impairment, hypertension, loss of hearing, haematuria,
proteinuria and lens abnormalities.
61. • SCURVY:
Ascorbic acid (vitamin C) acts as a cofactor in the synthesis of
collagen as it is necessary for hydroxylation of proline and lysine.
Results in defective formation and maintenance of collagen,
impairment or cessation of osteoid formation and impaired
osteoblastic function.
Optimal level of ascorbic acid is apparently required to maintain the
integrity of the periodontal microvasculature.
62. • ROLE IN GINGIVITIS:
Collagenolytic activity is increased in inflamed gingival tissue by the
enzyme collagenase.
Initial lesion-perivascular loss of collagen
Early lesion-increase in the amount of collagen destruction is seen.
Estabilished lesion-collagen fibers are destroyed around the infiltrate
of intact and disrupted plasma cells, neutrophils, lymphocytes,
monocytes and mast cells.
63.
64. • ALTERED COLLAGEN METABOLISM IN DIABETES:
- In addition to defects in collagen production, post translational modifications of
the collagen peptide have also been reported to occur in diabetes.
- Increased cross linking of collagen occurs normally with aging, but it is
accelerated in diabetic skin and tendon and may lead to decreased solubility and
increased accumulation of collagen in tissues throught an increased half life.
- Non enzymatic glycosylation of collagen is also increased in diabetes,which may
affect collagen metabolism by also changing the half life of the collagen peptide.
- It is possible that these post translational modifications of collagen in diabetes
may lead to excess collagen accumulation under conditions where there is
decreased synthesis of collagen.
65. CONCLUSION
• Collagens are fascinating proteins not only because they are unique in structure
and function, but also because of their ubiquitous distribution throughout the
animal kingdom.
• The collagens represent a family of atleast 28 types that have various distribution
patterns and functions in different connective tissues.
• They are synthesized in a complex series of biochemical events and its synthesis is
highly regulated.
• Mechanisms that regulate collagen synthesis have a direct bearing effect on
periodontal structures in which the connective tissue especially collagen undergo
dramatic changes.
• Periodontal regeneration is also intertwined with events associated with collagen
production and degradation.
66. REFERENCES
Bartold PM, Narayanan AS. Biology of the periodontal connective tissues.
Structure, Biosynthesis and Regulation of Collagen. Ch.4; p. 73-92.
Lippincott’s biochemistry:3rd edition;2005;pg 43-48
Orban’s Oral Histology and Embryology
T Ahuja,V Dhakray,M Mittal et al.Role of Collagen in the periodontal
ligament- A Review.The interent journal of Microbiology;10(1):1-7
K. Gelse et al. Collagen-structure,function and biosynthesis.Advanced
Drug Delivery Reviews 2003; 55 : 1531–1546
Spanheimer R,Umpierreez G.Decreased collagen production in diabetic
rats.Diabetes 1988 April;37(4):371-376
Kaur P,Kakar V. Collagen: Role in Oral Tissues: A Review.International
Journal of Science and Research. May 2014;3(5):273-276