Pathology Flashcards
what apoptosis pathway is used in tissue remodeling in embryogenesis?
Intrinsic pathway
What occurs in the intrinsic pathway?
Increased Bax (pro-apoptotic) and decreased Bcl-2 (anti-apoptotic) lead to increased cytochrome C –> activation of cellular caspases
What two methods can activate the Extrinsic apoptotic pathway?
- ligand receptor interactions - Fas-L with Fas-R (CD 95)
2. cytotoxic T cell releases perforin and granzyme B
Is ribosomal detachment (decreased protein synthesis) an irreversible or a reversible form of cellular injury?
reversible with the presence of O2
what electrolyte influx can cause activation of caspases?
Calcium influx
what is the real cause of reperfusion injury?
damage due to free radicals
what do you get with free radical oxidation of lipids?
Lipofuschin - yellow brown granules in the cytoplasm
what are the acute inflammation cytokines?
IL-1, IL-6, TNF-alpha
what is the chronic inflammatory cytokine?
TNF alpha
what are the possible outcomes of acute inflammation ?
Complete resolution, abscess formation, progression to chronic inflammation
what are the possible outcomes of chronic inflammation?
Scarring and amyloidosis
what is a granuloma?
A form of chronic inflammation; nodular collections of epithelioid macrophages and giant cells
If you have a patient with granulomatous inflammation, what might you want to treat your patient with and why?
Infliximab because it blocks TNF-alpha
make sure to do a PPD first! Infliximab can cause reactivation of TB
Is metaplasia reversible or irreversible?
Metaplasia is a reversible change where one cell type is replaced by another due to a stressor
Name the 4 steps of leukocyte extravasation.
- Rolling
- Tight binding
- Diapedesis (leukocyte travels between endothelial cells and exists blood vessel)
- Migration (leukocyte travels through interstitium to site of injury or infection guided by chemotactic signals
What are the chemotactic signals released in response to bacteria?
CILK
C5a, Il-8, LTB4, Kallikrein
what induces the selectins on the endothelial cells to make them sticky?
IL1, IL6, TNF-alpha
A patient presents with neutrophilia, recurrent bacterial infections, absent pus formation and delayed separation of the umbilical cord. What is the deficiency and what is the defect?
This patient has leukocyte adhesion deficiency. The defect is in LFA-1 integrin (CD18) on phagocytes
Name 3 enzymes that can eliminate free radicals
- catalase
- superoxide dismutase
- glutathione peroxidase
what 3 vitamins are considered antioxidants?
Vitamins A, C, E
What are the 3 phases of wound healing and their time frame?
- Inflammatory - immediate
- Proliferative - 2 to 3 days after wound
- Remodeling - 1 week after wound
what are the mediators in the inflammatory phase of wound healing and what are the characteristics?
Mediators: Platelets, neutrophils, macrophages
Characteristics: Clot formation, increased vessel permeability and neutrophil migration into tissue; macrophages clear debris 2 days later
What are the mediators in the proliferative phase of wound healing and what are the characteristics?
Mediators: Fibroblasts, myofibroblasts, endothelial cells, keratinocytes, macrophages
Characteristics: Deposition of granulation tissue and collagen, angiogenesis, epithelial cell proliferation, dissolution of clot and wound contraction (mediated by myofibroblasts)
what are the mediators in the remodeling phase of wound healing and what are the characteristics?
Mediator: Fibroblast
Characteristics: Type III collagen replaced by type I collagen, increased tensile strength of tissue
what induces and maintains granuloma formation?
TNF-alpha from macrophages
This is why anti-TNF drugs can cause granuloma break down as a side effect, and lead to disseminated disease
What are the causes of transudate?
Increased hydrostatic pressure
decreased oncotic pressure
sodium retention
What is the specific gravity of transudate?
<1.012
What are the causes of exudate?
lymphatic obstruction
inflammation
What is the specific gravity of exudate?
> 1.020
Name 3 conditions that have a decreased ESR.
- sickle cell disease
- polycythemia vera
- CHF
What is the mechanism of iron poisoning that causes problems?
Cell death due to peroxidation of membrane lipids and generation of free radicals
what symptoms can you see with acute iron poisoning? chronic iron poisoning?
Acute - gastric bleeding - hematemesis with abdominal pain or hypovolemic shock
Chronic - metabolic acidosis, scarring leading to FI obstruction
A pathology report shows abnormal aggregation of proteins or their fragments into Beta pleated sheet structures leading to cell damage and apoptosis. The tissue also has a waxy appearance. what is the diagnosis?
Amyloidosis
what two growth factors allow for sustained angiogenesis in cancer?
vEGF and bFGF (basic fibroblast growth factor)
What is the general neoplastic progression in cancer?
Normal to hyperplasia to carcinoma in situ to invasive carcinoma to metastasis
Abnormal proliferation of cells with loss of size, shape and orientation
Dysplasia