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General Pathology. Basic Principles of Cellular and Organ Pathology Infection - II. Jaroslava Dušková Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague. nonliving physical chemical. Inflammation - causes. living prions (?) viral bacterial mycotic parasitic AUTOIMMUNE.
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General Pathology Basic Principles of Cellular and Organ Pathology Infection - II Jaroslava Dušková Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague
nonliving physical chemical Inflammation - causes • living prions (?) viral bacterial mycotic parasitic AUTOIMMUNE
Infectious Agents of Humans Viruses • virion • obligate intracellular • either DNA(adeno-, herpes-, pox-, cytomegalo-, EB, papova, HPV, .. • or RNA (picorna – entero-, polio-, coxsackie-, arbo-, rhino-, myxo-, paramyxo- RS, rubeola, rhabdo-, retro-,)
Virion • capsid helical symmetry icosaedral symmetry • genome DNA RNA
General Natural defenses Inflammation Immune status Successful transmission Site of attack Number of microorg. Pathogenicity Host & Microorganism Encounter
General age, race, nutrition, other diseases (diabetes) Natural defenses skin, mucose integrity mucus, cilliary action, unobstructed flow protective secretion (lysosym in tears, gastric acid, IgA Inflammation leucocytes macrophages -phagocytosis Immune status immunity (or lack of it) active, passive immunisation, contact lymphocytes immunoglobulins complement Host
Successful transmission Site of attack Number of microorg. Pathogenicity invasiveness toxin production multiplication resistence to host defence mechanisms ability to cause necrosis enzyme release Microorganism
Virus – Host Cell Interaction • cytocidal • stabilised (steady– state) • transformation – ONCOGENS
Virus-Induced Injury • cell entering - surface ligands – viral tropism • translocation of the entire virus • fusion of the viral envelope with the cell membrane • receptor mediated endocytosis • intracellular replicative phase – forming ofvirions using virus specific enzymes • virus assembly & release extracellular phase
Virus – Organism Interaction • infected cell lysis by antibody and complement • cell mediated immunitylymphocytes macrophages interferon
Virus-Induced Injury Host cell responses: • DNA, RNA and protein synthesis • metabolic derangements • cell lysis / cell fusion • multinuclear formation • viral inclusions
Infectious Agents of Humans Viruses • virion • obligate intracellular • either DNA(adeno, herpes, pox, cytomegalo, EB, papova, HPV, .. • or RNA (picorna – entero, polio, coxsackie arbo, rhino, arbo, myxo, paramyxo, RS, rubeola, rabdo, retro,)
The Herpes viruses • Herpes simplex HSV 1,2 • Varicella-Zoster chickenpox-shingles • Cytomegalovirus CMV infection • Epstein-Barr virus EBV infectious mononucleosis - glandular fever, Burkitt´s lymphoma
The respiratory viruses • Influenza influenza • Parainfluenza croup, pneumonia • RS bronchiolitis, pneumonia • Adeno- pharyngitis, conjunctivitis • Rhino- colds • Corona & Reo- colds, SARS
Viral Infections of Childhood • Measles – morbilli • Mumps – parotitis epidemica • German measles – rubeola • Fifth disease – erythema infectiosum- human parvovirus dis.
Poliomyelitis anterior acuta Frequency • United States • No cases of wild-type poliovirus infection reported in the United States since 1979. • Until 1998, an average of 8-10 cases associated with the vaccine virus every year. • Four cases of vaccine-derived poliovirus were identified in 2005 among unvaccinated children in an Amish community in Minnesota. • International • The global incidence decreased by more than 99% since 1988. • No outbreaks reported in the western hemisphere since 1991 • An outbreak in Haiti and the Dominican Republic in 2001. • Clusters of wild-type disease still found in some areas in Africa and Southeast Asia. • By 2004, the only 6 countries in which wild poliovirus transmission had not been interrupted were India, Egypt, Nigeria, Niger, Pakistan, and Afghanistan. • An increase in the number of cases was observed in 2006.
Tick Born Encephalitis • tick-borne encephalitis virus a member of the family Flaviviridae • virus initially isolated in 1937. • A closely related virus in Far Eastern Eurasia, Russian spring-summer encephalitis virus responsible for a similar disease with a more severe clinical course.
Marburg and Ebola Virus Infections Pathogenesis • increase in vascular permeability • hemorrhagic diathesis • interstitial edema in visceral organs and brain • DIC • liver necrosis • renal tubular necrosis • terminal DIC/shock syndrome
Virus – Host Cell Interaction • cytocidal • stabilised (steady– state) • transformation – ONCOGENS
DNA HPV SV 40 – polyoma Adenoviruses Herpesviruses Epstein– Barr Hepatitis B RNA Rous sarcoma Leukemia HIV Oncogenic Viruses