Multiple Choice Question Test - XI (Basic Periodontology).
It is a group of diseases characterized by the inability of the phagocyte to reduce oxygen. Because the host phagocytes are unable to mount a normal respiratory burst (ie., reduce oxygen) they have difficulty controlling organisms which do not release reduced oxygen metabolites themselves. Apparently, catalase negative bacteria release enough hydrogen peroxide to assist neutrophils perform oxidative killing. The inability to rapidly dispatch bacteria which gain access to the connective tissues leads to the formation of granulomas by the chronic immune cells. CGD is not strongly associated with periodontitis, suggesting that phagocyte defense against facultative bacteria invading “normoxic” connective tissue is less important than defense against anaerobic bacteria in hypoxic gingival crevice.
These are found in two forms, α1 and α 2.
Mol wt. 41KDa to 200KDa.
α 1 consists of 2 fractions. It combines with billirubin. It is carrier for steroids, lipids and glycoproteins.
α 2 consist of α 2 microglobulins, mucoproteins & ceruloplasmin.
β- Globulins: Mol wt. 90,000- 1,300,000Da. pH -5.6. it is of following types
β lipoprotein – which helps in carriage of lipids, steroids and caroteine.
Globulin- which help in carriage of iron i:e transferin.
Prothrombin is a beta globulin.
Mol wt. 150,000Da to 190,000Da
ph is 6
These are antibodies.
The basic structural collagen unit is tropocollagen. It consists of 3 linear polypeptide chains (α 1,2,3) of 1,000 amino acid residues that intertwine forming a triple helix 300 nm long and 15 A wide. Type I predominates and is found in all CT, especially skin and bone; type II is found mainly in cartilage. Type III is present primarily in smooth muscle, especially blood vessels. Type IV is found in basement membranes. Glycine accounts for onethird of all amino acids in collagen. Collagen is also rich in projine, hydroxyproline, and hydroxylysine.
CD1 = an MHC-like molecule that presents lipid molecules.
CD3 = the signaling component of the T-cell receptor (TCR) complex.
CD4 = a co-receptor for the TCR that is found on T-helper cells; also a receptor used by HIV to
enter T cells.
CD8 = a co-receptor for the TCR that is found on cytotoxic T cells.
CD31 = PECAM-1, a cell adhesion molecule on platelets and endothelial cells.
CD35 = Complement receptor 1 (C3b/C4b receptor).
CD36 = Platelet glycoprotein IV or IIIb (GP IV / GP IIIb).
CD56 = a marker for natural killer cells and some T-lymphocytes.
CD71 = Transferrin receptor, mediates cellular uptake of iron.
CD117 = c-kit, the receptor for Stem Cell Factor, a glycoprotein that regulates cellular
differentiation, particularly in hematopoiesis.
CD120 = a receptor for Tumour Necrosis Factor, an inflammatory cytokine.
CD142 = Tissue factor, a major initiator of blood-clotting.
CD143 = Angiotensin-converting enzyme.
CD144 = VE-Cadherin, a calcium-dependent adhesion molecule at intercellular junctions, found only
in the vascular endothelium.
CD202a = Tie2, the receptor for angiopoietins, a family of angiogenic factors
The major MMPs in neutrophils are MMP-8 (collagenase-2) and MMP-9 (gelatinase B). While MMP-
8 is able to potently to degrade interstitial collagens, MMP-9 is a gelatinolytic enzyme degrading several extracellular matrix proteins, including basement membrane (type IV) collagen. MMP-8 and -9 are the main collagen-degrading enzymes in GCF and saliva (77, 109), and they are believed to be mainly responsible for collagen degradation in inflamed tissue during gingivitis and adult periodontitis
Reference: Uitto V J et al.Proteolytic host cell enzymes in gingival crevice fluid. Periodontology 2000, Vol. 31, 2003, 77–104.
T.denticolais an oral spirochetes normally cultivated in vitro under anaerobic conditions. However anaerobiosis is not an absolute requirements for the cultivation of this spirochetes. T.denticola is especially sensitive to oxygen. Although T.denticola lives predominantly in an anaerobic environment and it is capable of utilizing low levels of oxygen and protecting itself from oxygen radicals.
Reference: Loesche WJ. Oxygen sensitivity of various anaerobic bacteria. Appl Microbiol. 1969; 18: 723-7.
The periodontal ligaments of primary teeth are wider than those found in permanent teeth.
Colony-stimulating factors (CSF) were named for their ability to induce the development of distinct cell lineages. Erythropoietin is a cytokine produced by the kidney that stimulates proliferation and differentiation of erythroid cells into erythrocytes. Macrophage-CSF (M-CSF) and granulocyte-CSF (G-CSF) more specifically promote the differentiation of macrophages and granulocytes respectively. IL-3 is a CSF known as multi-CSF. It stimulates the formation of all lymphocytes.
Lipoxin A4 (LXA4), a derivative of arachidonic acid formed by lipoxygenases (LO), has endogenous
anti-inflammation and resolution properties. LXA4 was described to block IL-1β and TNF-α release in a time- and concentration-dependent manner, and consequently to inhibit leukocyte trafficking.
Reference: G.P. Garlet. Destructive and Protective Roles of Cytokines in Periodontitis: A
Re-appraisal from Host Defense and Tissue Destruction Viewpoints. J Dent Res 89(12):1349-1363, 2010
Synonyms for Hypophospahatasia are
- Rathbun disease