medigraphic.com

2004, Number 2

<< Back Next >>

Bioquimia 2004; 29 (2)

Phagocytosis: mechanisms and consequences. Part three

Rojas-Espinosa O, Arce-Paredes P

Language: Spanish
References: 125
Page: 55-67
PDF size: 263.54 Kb.


ABSTRACT

In 1880 Elli Metchnikoff established the phagocytic cells’ function as an essential process for the survival of animal species. In the unicellular organisms, such as the protozoa, the phagocytic function is the only means through which these organisms acquire their next meal. The phagocytic function improves through evolution and remains so in the more evolved species, although here the primary function of phagocytes is no longer a nourishment-related activity but it turns into an efficient mechanism of protection against infectious agents and of elimination of senescent or abnormal cells. Every step of the phagocytic process (migration, adhesion, endocytosis and particle destruction) appears each time more complex, and new molecules and mechanisms are continuously discovered. Although the whole phagocytic process is not yet fully understood, now we have a better panorama on the way phagocytic cells recognize those particles that must be eliminated and the mechanisms following thereafter. In this article a concise review is made on the phagocytic process and its importance as a protection mechanism of vertebrates, pointing out those aspects receiving major attention at the present, including cell-structure, adhesion proteins, phagocytosis-endowed receptor molecules, signalling pathways and participant molecules, maturation of phagosomes, and the role of the nitrogen and oxygen-derived intermediaries as potent antimicrobial toxins.


REFERENCES

  1. Aderem A, Underhill DM. Mechanisms of phagocytosis in macrophages. Annu Rev Immunol 1999; 170: 593-623.

  2. Underhill DM, Ozinsky A. Phagocytosis of microbes: complexity in action. Annu Rev Immunol 2002; 20: 825-852.

  3. Greenberg S, Grinstein S. Phagocytosis and innate immunity. Curr Opin Immunol 2002; 14: 136-145.

  4. Bainton DF, Ullot JL, Farquhar MG. The development of neutrophilic polymorphonuclear leukocytes in human bone marrow. J Exp Med 1971; 134: 907-939.

  5. Dransfield I, Buckle AM, Savill JS, McDowall A, Haslett C, Hogg N. Neutrophil apoptosis is associated with a reduction in CD16 (Fc gamma RIII) expression. J Immunol 1994; 153: 1254-1263.

  6. Gallin JI. Leukocyte adherence-related glycoproteins LFA-1, Mo-1, and p150, 95: A new group of monoclonal antibodies, a new disease, and a possible opportunity to understand the molecular basis of leukocyte adherence. J Infect Dis 1985; 152: 661-664.

  7. Etzioni A. Integrins: The glue of life. Lancet 1999; 353: 341-343.

  8. Carlos TM, Harlan JM. Leukocyte-endothelial adhesion molecules. Blood 1994; 84: 068-2101.

  9. Frenette PS, Wagner DD. Adhesion molecules-Part II: blood vessels and blood cells. New Engl J Med 1996; 335: 43-48.

  10. Rosales C, Brown EJ. Neutrophil receptors and modulation of the immune response. In: The Neutrophil. Ed for JS Abramson and JG Wheeler, Oxford University Press, London 1993: 23-62.

  11. Hayward AR, Harvey BA, Leonard J, Greenwood MC, Wood CB, Soothill JF. Delayed separation of the umbilical cord, widespread infections, and defective neutrophil mobility. Lancet 1979; 26: 1099-1001.

  12. Abramson JS, Mills EL, Sawyer MK, Regelmann WR, Nelson JD, Quie PG. Recurrent infections and delayed separation of the umbilical cord in an infant with abnormal phagocytic cell locomotion and oxidative response during particle phagocytosis. J Pediatrics 1982; 99: 887-894.

  13. Arnaout MA, Pitt J, Cohen HJ, Melamed J, Rosen FS, Colten HR. Deficiency of a granulocyte-membrane glycoprotein (gp150) in a boy with recurrent bacterial infections. New Engl J Med 1982; 306: 693-699.

  14. Crowley CA, Curnutte JT, Rosin RE, Schwartz J, Gallin JI, Klempner M, et al. An inherited abnormality of neutrophil adhesion. Its genetic transmission and its association with a missing protein. New Engl J Med 1980; 302: 1163-1168.

  15. Kohl S, Springer TA, Schmalstieg FC, Loo LS, Anderson DC. Defective natural killer cytotoxicity and polymorphonuclear leukocyte antibody-dependent cellular cytotoxicity in patients with LFA-1/OKM-1 deficiency. J Immunol 1984; 133: 2972-2978.

  16. Arnaout MA, Todd RF, Dana N, Melamed J, Schlossman SF, Colten HR. Inhibition of phagocytosis of complement C3- or immunoglobulin-coated particles and of C3bi binding by monoclonal antibodies to a monocyte-granulocyte membrane glycoprotein (Mo1) J Clin Invest 1983; 72: 171-179.

  17. Anderson DC, Schmalsteig FC, Finegold MJ, Hughes BJ, Rothlein R, Miller LJ, et al. The severe and moderate phenotypes of heritable Mac-1, LFA-1 deficiency: their quantitative definition and relation to leukocyte dysfunction and clinical features. J Infect Dis 1985; 152: 668-689.

  18. Patarroyo M, Beatty PG, Serhan CN, Gahmberg CG. Identification of a cell-surface glycoprotein mediating adhesion in human granulocytes. Scand J Immunol 1985; 22: 19-631.

  19. Beller DI, Springer TA, Schreiber RD. Anti-Mac-1 selectively inhibits the mouse and human type three complement receptor. J Exp Med 1982; 156: 1000-1009.

  20. Wright SD, Rao PE, Van Voorhis WC, Craigmyle LS, Lida K, Talle MA, et al. Identification of the C3b1 receptor of human monocytes and macrophages by using monoclonal antibodies. Proc Natl Acad Sci (USA) 1983; 80: 5699-5703.

  21. Page RC, Sims TJ, Geissler F, Altman LC, Baab DA. Defective neutrophil and monocyte motility in patients with early onset periodontitis. Infect Immun 1985; 47: 169-175.

  22. Van Dyke TE, Horoszewics HU, Cianciola LJ, Genco RJ. Neutrophil chemotaxis dysfunction in human periodontitis. Infect Immun 1980; 27: 124-132.

  23. Frenette PS, Wagener DD. Adhesion molecules-Part I. New Engl J Med 1996; 335: 1526-1529.

  24. Phillips ML, Schwartz BR, Etzioni A, Bayer R, Ochs HD, Paulson JC, et al. Neutrophil adhesion in leukocyte adhesion deficiency syndrome type 2. J Clin Invest 1995; 96: 2898-2906.

  25. Marquardt T, Brune T, Luhn K, Zimmer KP, Fabritz L, van der Werft N, et al. Leukocyte adhesion deficiency II syndrome, a generalized defect in fucose metabolism. J Pediatr 1999; 134: 681-688.

  26. Marquardt T, Luhn K, Srikrishna G, Freeze HH, Harms E, Westweber D. Correction of leukocyte adhesion deficiency type II with oral fucose. Blood 1999; 94: 3976-3985.

  27. Linder ME, Gilman AG. G proteins. Sci Amer 1992; 267: 36-43.

  28. Lefkowitz RJ. Clinical implications of basic research. G proteins in medicine. New Engl J Med 1995; 332: 186-187.

  29. Birnbaumer L, Birnbaumer M. Signal transduction by G proteins. J Recept Signal Transduct Res 1997; 15: 213-252.

  30. Quinn MT, Parkos CA, Walker L, Orkin SH, Dinauer MC, Jesaitis AJ. Association of a ras-related protein with cytochrome b of human neutrophils. Nature 1989; 342: 198-200.

  31. Bokoch GM. Signal transduction by GTP binding proteins during leukocyte activation of phagocytic cells. Curr Top Membr Transp 1990; 35: 65-111.

  32. Bokoch GM. Regulation of cell function by Rho family GTPases. Immunol Res 2000; 21: 139-148.

  33. Aderem A. The Marcks brothers: A family of protein kinase C substrates. Cell 1992; 71: 713-716.

  34. Rosen A, Keenan KF, Thelen M, Nairn AC, Aderem A. Activation of PKC results in the displacement of its myristoilated, alanin-rich substrate from punctuate structures in macrophage filopodia. J Exp Med 1990; 172: 1211-1215.

  35. Kyat M, Anderson S, Allen LA, Aderem A. MARKS regulates membrane ruffling and cell spreading. Curr Biol 1997; 7: 611-614.

  36. Vicente-Manzanares M, Sancho D, Yáñez-Mó, M, Sánchez-Madrid M. The leukocyte cytoskeleton in cell migration and immune interactions. Internat Rev Cytol 2002; 216: 233-289.

  37. Olmsted JB, Borisy GG. Microtubules. Annu Rev Biochem 1973; 42: 507-540.

  38. Lazarides E, Weber K. Actin antibody: The specific visualization of actin filaments in non-muscle cells. Proc Nat Acad Sci 1974; 71: 2268-2272.

  39. Weber K, Groeschel-Stewart U. Antibody to myosin: the specific visualization of myosin-containing filaments in nonmuscle cells. Proc Natl Acad Sci 1974; 71: 4561-4564.

  40. Lazarides E. Tropomyosin antibody: the specific localization of tropomyosin in non-muscle cells. J Cell Biol 1975; 65: 549-561.

  41. Janmey PA. Mechanical properties of cytoskeletal polymers. Curr Opin Cell Biol 1991; 3: 4-11.

  42. Sarndahl E, Lindroth M, Bengtsson T, Farllman M, Gustavsso J, Stendahl O, et al. Association of ligand-receptor complexes with actin filaments in human neutrophils: A possible regulatory role for a G-protein. J Cell Biol 1990; 109: 2791-2799.

  43. Southwick FS, Young CL. The actin released from profilin-actin complexes is insufficient to account for the increase in F-actin in chemoattractant-stimulated polymorphonuclear leukocytes. J Cell Biol 1990; 110: 1965-1973.

  44. Snyderman R. Regulatory mechanisms of a chemoattractant receptor on human polymorphonuclear leukocytes. Rev Infect Dis 1985; 7: 390-394.

  45. Saba TM. Aespecific opsonins. In: The human system and infectious diseases. Karger, Basel 1975. pp. 489-504.

  46. Kaplan G. Differences in the mode of phagocytosis with Fc and C3 receptors in macrophages. Scand J Immunol 1977; 6: 797-807.

  47. Johnson E, Eskeland T. Complement C3b receptor mediated phagocytosis of agarose beads by mouse macrophages. I. Intracellular degradation of agarose-bound C3bi and C3b by lysosomal enzymes. Scand J Immunol 1983; 18: 193-200.

  48. Johnson E, Gauperaa T, Eskeland T. Fibronectin binds to complement-coated agarose beads and increases their association to mouse macrophages. Scand J Immunol 1985; 22: 315-320.

  49. Bevilacqua MP, Amrani D, Mosesson MW, Bianco C. Receptors for cold insoluble globulin (plasma fibronectin) on human monocytes. J Exp Med 1981; 153: 42-60.

  50. Proctor RA. Fibronectin: an enhancer of phagocytic function. Rev Infect Dis 1987; 9: 412-419.

  51. Wright SD, Silverstein S. Tumor promoting phorbol esters stimulate C3b and C3bi receptor-mediated phagocytosis in cultured human monocytes. J Exp Med 1982; 156: 1149-1164.

  52. Bianco C, Griffin FM, Silverstein SC. Studies of the macrophage complement receptor. Alterations of receptor function upon macrophage activation. J Exp Med 1975; 141: 1278-1282.

  53. Wright SD, Craigmyle LS, Silverstein SC. Fibronectin and serum amyloid P component stimulate C3b and C3bi-mediated phagocytosis in cultured human monocytes. J Exp Med 1983; 158: 1338-1343.

  54. Griffin JA, Griffin FM. Augmentation of macrophage complement receptor function in vitro. I. Characterization of the cellular interactions required for the generation of a T-lymphocyte product that enhances macrophage complement receptor function. J Exp Med 1979; 150: 653-675.

  55. Tulkens P, Schneider YJ, Trouet A. The fate of the plasma membrane during endocytosis. Biochem Rev 1977; 5: 1809-1815.

  56. Medzhitov R. Janeway CH. Innate immunity. New Engl J Med 2000; 343: 338-344.

  57. Ravetch JV. Fc receptors: rubor redux. Cell 1994; 78: 553-560.

  58. Ravetch JV. Fc receptors. Curr Opin Immunol 1997; 9: 121-125.

  59. Unkeless JC, Jin J. Inhibitory receptors, ITIM sequences and phosphatases. Curr Opin Immunol 1997; 9: 338-343.

  60. Reth M. Antigen receptor tail clue. Nature 1989; 338: 383-384.

  61. Strzelecka A, Kwiatkowska K, Sobota A. Tyrosine phosphorylation and Fc gamma receptor-mediated phagocytosis. FEBS Lett 1997; 400: 11-14.

  62. Greenberg S. Signal transduction of phagocytosis. Trends Cell Biol 1995; 5: 93-99.

  63. Agarwal A, Salem P, Robbins KC. Involvement of p72syk, a protein-tyrosine kinase in Fc gamma receptor signalling. J Biol Chem 1993; 268: 15900-15905.

  64. Kiener PA, Rankin BM, Burkhardt AL, Schieven GL, Gilliland LK, Rowley RB, et al. Cross-linking of FcgRI and FcgRII on monocytic cells activates a signal transduction pathway common to both Fc receptors that involves the stimulation of p72 Syk protein tyrosine kinase. J Biol Chem 1993; 268: 24442-24448.

  65. Ghazizadeh S, Bolen JB, Fleith HB. Tyrosine phosphorylation and association of Syk with FcgRII in monocytic THP-1 cells. Biochem J 1995; 74: 669-674.

  66. Cox D, Chang P, Kurosaki T, Greenberg S. Sky tyrosine kinase is required for immunoreceptor tyrosine activation motif-dependent actin assembly. J Biol Chem 1996; 271: 16597-16602.

  67. Greenberg S. Modular components of phagocytosis. J Leuk Biol 1999; 66: 712-717.

  68. Ridley AJ, Paterson HF, Johnston CL, Diekmann D, Hall A. The small GTP-binding protein rac regulates growth factor-induced membrane ruffling. Cell 1992; 70: 401-410.

  69. Modlin RL, Brightbill HD, Godowski PJ. The Toll of innate immunity on microbial pathogens. New Engl Med 1999; 340: 1834-1835.

  70. Anderson KV. Toll signalling pathways in the innate immune response. Curr Opin Immunol 2000; 12: 13-19.

  71. Jeoung-Sook S, Zhimin G, Soman NA. Involvement of cellular caveolae in bacterial entry into mast cells. Science 2000; 289: 785-788.

  72. Schlegel A, Lisanti MP. Caveolae and their coat proteins, the caveolins: from electron microscopy novelty to biological launching pad. J Cell Physiol 2001; 186: 329-337.

  73. Rosenberg CM, Brumell JH, Finlay BB. Microbial pathogenesis: lipid rafts as pathogen portals. Current Biol 2000; 10: R823-R825.

  74. Swanson JA, Baer SC. Phagocytosis by zippers and triggers. Trends Cell Biol 1995; 5: 89-93.

  75. Pitt A, Mayorga LS, Stahl PD, Schwartz AL. Alterations in the protein composition of maturing phagosomes. J Clin Invest 1992; 90: 1978-1983.

  76. Racoosin EL, Swanson JA. Macropinosome maturation and fusion with tubular lysosomes in macrophages. J Cell Biol 1993; 121: 1011-1020.

  77. Desjardins M, Huber LA, Parton RG, Griffiths G. Biogenesis of phagolysosomes proceeds through a sequential series of interactions with the endocytic apparatus. J Cell Biol 1994; 124: 677-688.

  78. de Chastellier C, Thilo L. Phagosome maturation and fusion with lysosomes in relation to surface property and size of the phagocytic particle. Eur J Cell Biol 1997; 74: 49-62.

  79. Berthiaume EP, Medina C, Swanson JA. Molecular size-fractionation during endocytosis in macrophages. J Cell Biol 1995; 129: 989-998.

  80. Desjardins M, Nizala NN, Corsini R, Rondeau C. Maturation of phagosomes is accompanied by changes in their fusion properties and size-selective acquisition of solute materials from endosomes. J Cell Sci 1997; 110: 2303-2314.

  81. Diakonova M, Gerke V, Ernst J, Liautard JP, van der VG, Griffiths G, et al. Localization of five annexins in J774 macrophages and on isolated phagosomes. J Cell Sci 1997; 110: 1199-1213.

  82. Pizon V, Desjardins M, Bucci C, Parton RG, Zerial M. Association of rap-1a and rap-1b proteins with late endocytic phagocytic compartments and rap-2a with the Golgi complex. J Cell Sci 1994; 107: 1661-1670.

  83. Gorvell JP, Chavrier P, Zerial M, Gruenberg J. Rab5 controls early endosome fusion in vitro. Cell 1991; 64: 915-925.

  84. Feng Y, Press B, Wandinger-Ness A. Rab7: an important regulator of late endocytic membrane traffic. J Cell Biol 1995; 131: 1435-1452.

  85. Claus V, Jahraus A, Tjelle T, Berg T, Kisrchke H, Faulstich H, et al. Lysosomal enzyme trafficking between phagosomes, endosomes and lysosomes in J774 macrophages. Enrichment of cathepsin H in early endosomes. J Biol Chem 1998; 273: 9842-9851.

  86. Blocker A, Severin FF, Burkhardt JK, Bingham JB, Yu H, Olivo JC, et al. Molecular requirements for bidirectional movement of phagosomes along microtubules. J Cell Biol 1997; 137: 113-129.

  87. Clague MJ. Molecular aspects of the endocytic pathway. Biochem J 1998; 336: 271-282.

  88. Jensen MS, Bainton DF. Temporal changes in pH within the phagocytic vacuole of polymorphonuclear neutrophilic leukocytes. J Cell Biol 1973; 56: 379-388.

  89. Sturgill-Koszycki S, Schlesinger PH, Chakraborty P, Haddix PL, Collins PL, Fok AK, et al. Lack of acidification in Mycobacterium phagosomes produced by exclusion of the vesicular proton-ATPase. Science 1994; 263: 678-681.

  90. Bainton DF. Neutrophilic granules. British J Haematol 1975; 29: 17-22.

  91. Spitznagel JK, Shafer WM. Neutrophil killing of bacteria by oxygen-independent mechanisms: A historical summary. Rev Infect Dis 1985; 7: 398-403.

  92. Tkalcevic J, Novelli M, Phylactides M, Iredale JP, Segal AW, Roes J. Impaired immunity and enhanced resistance to endotoxin in the absence of neutrophil elastase and cathepsin G. Immunity 2000; 12: 201-210.

  93. Spitznagel JK, Cooper MR, McCall AE. Selective deficiency of granules associated with lysozyme and lactoferrin in human polymorphs (PMN) with reduced microbicidal capacity. J Clin Invest 1972; 51: 93-95.

  94. Hansen NE, Andersen V. Lysozyme activity in human neutrophilic granulocytes. British J Haematol 1973; 24: 613-622.

  95. Sly WS, Quinton BA, McAlister WH, Rimoin DL. Beta-glucuronidase deficiency: report of clinical, radiologic and biochemical features of a new mucopolysaccharidosis. J Pediatr 1973; 82: 249-257.

  96. Sato A. Chediak and Higashi’s disease. Probably identity of “a new leukocytal anomaly (Chediak) and congenital gigantism of peroxidase granules (Higashi)” Tohoku J Exp Med 1955; 61: 201-210.

  97. Dinauer MC, Orkin SH. Chronic granulomatous disease. Ann Rev Med 1992; 43: 117-124.

  98. Clark RA, Malech HL, Gallin JI, Nunoi H, Volpp BD, Pearson DW, et al. Genetic variants of chronic granulomatous disease: prevalence of deficiencies of two cytosolic components of the NADPH oxidase system. New Engl J Med 1989; 321: 647-652.

  99. Curnutte JT. Molecular basis of the autosomal recessive forms of chronic granulomatous disease. Immunodeficiency Rev 1992; 3: 149-172.

  100. Holmes B, Park BH, Malawista SE, Quie PG, Nelson DL, Good RA. Chronic granulomatous disease in females. A deficiency of leukocyte glutathione peroxidase. New Engl J Med 1970; 283: 217-221.

  101. Cooper MR, De Chatelet LR, McCall CE, LaVia MF, Spurr CL, Bahener RI. Complete deficiency of leukocyte glucose-6-phosphate dehydrogenase with defective bactericidal activity. J Clin Invest 1972; 51: 769-777.

  102. Gray GR, Stamatoyannopoulos G, Naiman SC, Kliman MR, Klebanoff SJ, Austin T, et al. Neutrophil dysfunction, chronic granulomatous disease and non-specific haemolytic anaemia caused by complete deficiency of glucose-6-phosphate dehydrogenase. Lancet 1973; 2: 530-534.

  103. Bellanti JA, Cants BE, Schlegel RJ. Accelerated decay of glucose-6-phosphate dehydrogenase activity in chronic granulomatous disease. Pediatr Res 1970; 4: 405-411.

  104. Erickson RP, Stites DP, Fudenberg HH, Epstein CJ. Altered levels of glucose-6-phosphate dehydrogenase-stabilizing factors in X-linked chronic granulomatous disease. J Lab Clin Med 1972; 80: 644-653.

  105. Babior BM. The respiratory burst oxidase. Hematol Oncol Clin North Amer 1988; 2: 201-212.

  106. Smith RM, Curnutte JT. Molecular basis of chronic granulomatous disease. Blood 1991; 77: 673-686.

  107. Bahener RL, Nathan DG. Quantitative nitroblue tetrazolium test in chronic granulomatous disease. New Engl J Med 1968; 278: 971-976.

  108. Ochs HD, Igo R. The NBT slide test: A simple screening method for detecting chronic granulomatous disease and female carriers. J Pediatr 1973; 83: 77-80.

  109. Klebanoff SJ. Iodination of bacteria: a bactericidal mechanism. J Exp Med 1967; 126: 1063-1076.

  110. Selvaraj RJ, Paul BB, Strauss RR, Jacobs AA, Sbarra AJ. Oxidative peptide cleavage and decarboxylation by the MPO-H2O2-Cl- antimicrobial system. Infect Immun 1974; 9: 255-260.

  111. Lazarus GM, Neu HC. Agents responsible for infection in chronic granulomatous disease of childhood. J Pediatr 1975; 86: 415-417.

  112. Woeber KA, Ingbar SH. Metabolism of L-thyroxin by phagocytosing human leukocytes. J Clin Invest 1973; 52: 1796-1803.

  113. Schultz J, Kaminker K. Myeloperoxidase of the leukocyte of normal human blood. I. Contents and localization. Arch Biochem Biophys 1962; 96: 465-467.

  114. Klebanoff SJ, Clem WH, Luebke RG. The peroxidase-tiocyanate-hydrogen peroxide antimicrobial system. Biochim Biophys Acta 1966; 117: 63-72.

  115. Curnutte JT, Whitten DM, Babior BM. Defective superoxide production by granulocytes from patients with chronic granulomatous disease. New Engl J Med 1974; 290: 593-597.

  116. Gregory EM, Fridovich I. Oxygen toxicity and the superoxide dismutase. J Bacteriol 1973; 114: 1193-1197.

  117. Boxer LA, Morganroth ML. Neutrophil function disorders. Dis Mon 1988; 33: 681-780.

  118. Allen RC, Mills EL, McNitt TR, Quie PG. Role of myeloperoxidase and bacterial metabolism in chemiluminescence of granulocytes from patients with chronic granulomatous disease. J Infect Dis 1981; 144, 344-348.

  119. Del Maestro RF, Thaw HH, Bjork J, Planker M, Arfors KE. Free radicals as mediators of tissue injury. Acta Physiol Scand 1980; S492: 43-57.

  120. Hibbs JB, Taintor RR, Vavrin Z. Macrophage cytotoxicity: Role for L-arginine deiminase and imino nitrogen oxidation to nitrite. Science 1987; 235: 473-476.

  121. Marletta MA, Yoon PS, Iyengar R, Leaf CD, Wishnok JS. Macrophage oxidation of L-arginine to nitrite and nitrate: nitric oxide is an intermediate. Biochemistry 1988; 27: 8706-8711.

  122. Edelson PJ, Stites DP, Gold S, Fudenberg HH. Disorders of neutrophil function. Defects in the early stages of the phagocytic process. Clin Exp Immunol 1987; 13: 21-28.

  123. Repo H. Defects in phagocytic functions. Ann Clin Res 1987; 13: 263-279.

  124. Axtell RA. Evaluation of the patient with a possible phagocytic disorder. Hematol Oncol Clin North Am 1988; 2: 1-12.

  125. Rojas-Espinosa O. Bioquímica de la Fagocitosis. Bioquimia 1997; 22: 612-637.




2020     |     www.medigraphic.com