Extra pathoma stuff Flashcards
P selections are upregulated by what molecules?
TNF alpha and IL-1
Adhesion molecules are upregulated by what molecules?
C5a and LTB4 (note how these are the same as the chemo attractants)
What do selectins bind to?
Sialyl Lewis X
What is the pathological basis of leukocyte adherence deficiency?
CD18 defect, leading to inability of PMNs to bind and exvascate
What are the clinical signs/symptoms of leukocyte adhesion deficiency? (3)
Delayed separation of umbilical cord
Increased circulating PMNs
Recurrent bacterial infx w/o pus
What is the pathological basis of chediak-higashi syndrome?
AR disease where micro tubules are defective
What are the clinical signs/symptoms of chediak-higashi syndrome? (4)
Increase pyogenic infx
Neutropenia
Albinism
Peripheral neuropathy
What is the pathological basis for chronic granulomatous disease?
NADPH oxidase deficiency, leads to ineffective immune killing, meaning granulomas everywhere
What are the five organisms that can infect patients with chronic granulomatous disease? What do they all have in common
S Aureus P Cepacia S marcescens Nocardia Aspergillus
All catalase positive
What materials induce a noncaseating granuloma formation? (6)
Foreign material Sarcoidosis Be exposure Crohn's disease Cat scratch disease
What materials induce a caseating granuloma? What are the tests that can detect these?
TB
AFB or GMS stain
What are the primary cells involved in a granuloma?
Epithelioid histiocytes (macrophages)
What is the shape that a granuloma from cat scratch disease forms?
Stellate
What are the histological characteristics of a caseating vs a non-caseating granuloma?
Noncaseating have a pink center
Caseating have a darker, “dead” center
Where do T cells from the bone marrow go to “mature”? What happens there?
Thymus–undergo tests for recognizing self and foreign.
What are the two steps of T cell activation?
- MHC binding
2. B7 ona APC binds CD28 on CD4 T cells
What is the function of CD4+ T cells?
Secrete cytokines to help inflammation (help either B cells or T cells)
What cells do Th1 cells help? What are the two cytokines they secrete, and what does each do?
Helps CD8+ T cells
Secretes IL-2 (CD8 growth factor)
IFN-gamma (macrophage activator)
What cytokines do Th2 cells secrete? (3)
- IL-4 (switch to IgG, IgE)
- IL-5 Eosinophil chemotaxis, IgA, mature B cells
- IL-10 (inhibits Th1 phenotypes)
What are the steps of CD8 T cell activation?
- MHC I presented
- IL-2 from CD4 provides second signal
- Cytotoxic T cells active
What are the ligands that Cytotoxic T cells use to kill? What does this do?
FasL binds Fas on target cell
Activates Caspases
What are the cytokines that Cytotoxic T cells use to actually effect killing? What does this do?
Perforins and Granzymes
What are the two Ig that B cells express on their surface?
IgM and IgD
How do B cells get activated? (2)
- Antigen binds IgM or IgD
2. CD4 interacts, with Cd40 binding CD40L
What are the cytokines that Th2 cells secrete to help B cells mature?
Il-4 and IL-5
What is the histological hallmark or Crohn’s disease? What about Ulcerative colitis?
Crohn's = Granulomas Ulcerative = Crypt abscesses
What are the three steps of granuloma formation?
- Macrophages present antigen via MHC II
- Macrophages secrete IL-12, inducing Th1 cells
- Th1 cells secrete IFN-gamma, converting macrophages to epithelioid histiocytes
Where are the stem cells in the large bowel?
Crypts
Where are the stem cells in the skin?
Basal layer
Where are the stem cells in the bone marrow?
Hematopoietic stem cells
What is the marker for Hematopoietic stem cells?
CD34
What is the stem cell of the lungs?
Type II alveolar cells
What type of collagen do fibroblasts secrete?
Collagen III
What are the three components of granulation tissue?
Capillaries
Myofibroblasts
Fibroblasts
What happens to the type III collagen that is initially deposited into scarred tissue?
Replaced by type I by collagenase
Where is Type I, II, III, and IV collagen seen?
1 Bone
- Cartilage
- Pliability
- basement membrane
Collagenase is an enzyme used to remove type III collagen from scar tissue, allowing for the replacement by Type I collagen. What is the cofactor needed for this enzyme?
Zn
What is the function of TGF-alpha (in terms of repair)?
Epithelial and fibroblast growth factor
What is the function of TGF-beta(in terms of repair)? (2)
Important fibroblast growth factor
Inhibits inflammation
What is the function of platelet derived growth factor (PDGF) (in terms of repair)?
Endothelium, smooth muscle growth factor
What is the function of fibroblast growth factor (FGF) (in terms of repair)? (2)
Angiogenesis/skeletal development
What is the function of VEGF (in terms of repair)?
Angiogenesis
What is the chemical structure of collagen?
G-X-Y (X is usually P)
What are the crosslinks of procollagen? What is the vitamin that is needed to do this?
OH groups on the Y group crosslink
What are the three nutrient deficiencies that can result in delayed wound healing?
- Vit C
- Cu
- Zn
What type of collagen that is deposited in a keloid?
Type III