Virus.pdf

# Vinis ## Contain the Genome RNA or DNA (Never both) - Viral Genome - contains linear or circular DNA, Single Stranded DNA, or linear RNA ## Capsid - Protects the virus - outer layer - Inpenetral cell around the nucleic acid core - made of a number of morphological Sub unit called a Capsomear -...

# Vinis ## Contain the Genome RNA or DNA (Never both) - Viral Genome - contains linear or circular DNA, Single Stranded DNA, or linear RNA ## Capsid - Protects the virus - outer layer - Inpenetral cell around the nucleic acid core - made of a number of morphological Sub unit called a Capsomear - Gives Symmetry - Made of protomears ## Envelope - (vinis is called 'naked vines' if no envelope) - Surrounds the nucleocapsid - Bilayer of lipoprotein and Glycoproteins *(Vinis' are smaller than bacteria)* ## Enzymes - - Central role in infection process - Some enzymes contain their own nucleic acid pulmonances which transcribes the viral genome into mRNA in the replication process ## Obligate Intracellular ## Parasites - Vinises can only multiply in a living host cell # Vims classification ## Icosahedral - Polygon - Capsid: 12 corners, 20 facets (equilateral triangles), 30 edges - Most stable - Found in human pathogenic viruses such as herpes - Types: Hexagon, Pentagon ## Filamentous - Linear thin thread/rod Shape - Capsid ## Head-tail - Icosahedral head - Capsid - Filamentous body - (mix of both) ## Viral Tropism Types: Cellular, Tissue, Host ### Influencing factors of tissue tropism: - Presence of cellular receptors permitting viral entry - Availability of transcription factors involved in neural replication - Cellular receptors of the proteins found on the cell or viral surface # Viral Infections of The Oral Cavity ## Varicella - Zoster (Human herpes virus 3) - Chicken Pox (children) - Shingles (Adults) ### Management - Hydration - Good diet - Non-steroidal/antiinflammatory drugs - Paracetamol, ibuprofen (to relieve fever) #### Shingles - Reactivation of the virus - Sits in the Dorsal root Ganglia - Triggered by trauma, drugs (immunosuppressant) - Virus is dormant - when reactivated it travels through the nerve fibres in the skin - Presents unilaterally (one sided) #### Management - Not for nsg to manage but can lead to Ramsay hunt (shingles of the facial nerve) - Unilaterally facial palsy - Tinnitus - Change/loss of taste - Causes dry mouth - Can present in the mouth - Pt may complain of tooth ache - but isn't as it is just hyposensitivity ## Herpangina - Presents on the soft palate - Present in children aged 3-10 years old - Can be present for up to 10 days - Can still be contagious for 3-8 weeks after getting the virus - Can cause difficulty swallowing ## Epstein-Barr Virus - Humanherpes vinis 4 - Can cause: - Burkitt's lymphoma - malignant tumour (developing/3rd world countries due to malaria) - Nasopharyngeal Carcinoma - common in South China, associated with diet ## Oral Hairy Leukoplasia - Most common in people with HIV/AIDS ## Paramyxoviridae Vims ### Mumps - Painful swelling of the parotid gland (side of the face) - Spread through coughs/sneezes - Most contagious 2-3 days before symptoms - Lasts 1-2 weeks - Soft diet - Long term consequences ## Measles - measles morbillivirus - Spots can present in oral cavity - Buccal mucosa - Hard and soft palate ## Herpes Simplex Virus 1 and 2 ➡️ Primary infection - Primary gingivostomatitis - Patient may present with malaise - Swollen lymphnodes - Eruptive sores around the face inside the oral cavity - Lasts 5-10 days - No scamming ## Genital Herpes - Contract during intercourse/sexual practices ## Hepetic Whitlow - Recurrent - (Seeing a patient with a coldsore) ## Enchephalitis - Swelling of the brain - Lead to death ## Secondary Infection ## Herpes Labialis (cold sore) - Lives in trigeminal ganglion until reactivated ### Stimulation of activation - Stress - Trauma (lip biting) - Sunlight (UV rays) - Menstruation - Immunosuppression - Fatigue