chronic and special types of inflammation (W11) Flashcards
4 clinical outcomes of acute inflammation
resolution
organisation
dissemination
chronic inflammation
resolution of inflammation - requirements?
elimination of cause of injury
recovery of tissue architecture
chromatin modification
anti-inflammatory processes?
efferocytosis
pro-resolving lipids promote clearance
neuroendocrine signals
name for macrophages engulfing apoptotic neutrophils
efferocytosis
pro-resolving lipids examples
lipoxins, resolvins, protectins
chromatin modification (epigenetic)?
changes future innate responses in tissue
boosted (trained immunity), lasts months-years
why does scar tissue favour disease progression
difficult to transverse therefore inflammatory cells slow down, get stuck, more likely to be activated
what wraps around inflamed intestine to create a contained area of inflammation, eg in late appendicitis
omentum
sepsis definition
life threatening organ dysfunction caused by a dysregulated hot response to infection
common infections associated with sepsis
pneumonia
abdominal infection
urinary tract infection
septic shock?
sepsis with high serum lactate and refractory low blood pressure requiring vasopressors after fluid resuscitation
clinical pathology of sepsis
cytokine storm
fluid leak syndromes
coagulopathy
neutrophil NETosis
what is NETosis
neutrophil ‘chucks out’ DNA - sticky to bacteria, also toxic (granule proteins).
effective way of trapping microorganisms but dangerous
problems with neutrophil NETosis (in sepsis)
fibrin clot blocks some vessels causing ischaemia.
lysis of clot occurs using up bodies platelets and fibrin, patients start to bleed
what can fluid leak in sepsis cause
compartment syndrome
intestinal mucosa swelling allows entry of bad microbes
fluid leak in lungs (requires ventilation creating more trauma)
sepsis recovery
white cell count plunges, platelet count rises
body tries to restrain inflammation, patients become immunosuppressed for months afterwards
monocytes 2 roles
sentinel patrol in vessels to survey epithelium
role in inflammation - enhanced migration, activation proliferation, and some become macrophages
why is abnormally persistent inflammation associated with increased risk of cancer
danger of inflammation and requirement to keep regenerating
inflammasomes problems?
can cause programmed form of cell death that is leaky - cytokines and inflammasomes leak out of cell becoming red flag for other inflammatory cells. inflammasomes very indigestible and can be produced in conditions unrelated to infection
how do scarred tissues become more conductive to inflammation
mechanotransduction
macrophage-myofibroblast stable circuit (new homeostasis).
4 special types of inflammation
inflammatory sinus & fistula
erosion & ulcer
abscess
granuloma
inflammatory sinus and fistula?
abnormal tract in an epithelial surface lined by granulation tissue
blind ending - sinus
linking 2 epithelial surfaces - fistula
ulcer definition
localised loss of full thickness of epithelial surface caused by removal of inflammatory necrotic tissue
(part of epithelium loss = erosion)
abscess?
pus in newly formed cavity, granulation tissue surrounds
characteristic of staphylococcal pneumonia?
lung abscesses
what can occur if abscesses arent surgically trained
rupture creating inflammatory sinus/fistula
granulomas?
organised clusters of mature activated macrophages in response to persistent stimuni
2 types of granuloma
low turnover (foreign body)
high turnover (immune)
