Random Flashcards
List 3 features to take into account when grading cancer
- Degree of differentiation
- Mitotic rate
- Nuclear grade
- Necrosis
- Pleomorphism
- Integrity of cells
List 4 characteristics used in the staging of cancer
- Site of the primary tumour
- Local spread into surrounding tissue
- Spread into lymphatics or veins
- Spread to local and distant lymph nodes
- Metastatic spread
- Involvement of excision margins
Describe the sequence of example events during carcinogenesis
Loss of response to growth control signals
Ability to promote angiogenesis
Ability to evade apoptosis
How does PTEN promote apoptosis?
PL3 kinase inhibition. PTEN dephosphorylates PIP2 -> PIP3. PIP3 activates Akt which blocks FOXO activity by phosphorylation resulting in decreased cell death.
What is a tumour suppressor gene, and give example.
Inhibitory genes regulating proliferation
p53, PTEN, BRCA1/2, APC, pRB, p27KIP1, p16INK4a
What is an oncogene, and give an example.
A gene that stimulates cell growth and proliferation, that is aberrantly expressed and insensitive to growth control signals. E.g. HER2, Ras, Raf, EGFR, CyclinD1, cMyc
Describe 2 differences between benign and malignant tumours
Malignant: Invades + Metastasises Fast Growth Less differentiated NOT encapsulated Abnormal mitoses
4 types of protozoa and examples of each
Amoeba - entamoeba histolyca
Coccidia - toxoplasma gondii
Flagellate - leishmania
Ciliate - balantidium coli (immunosuppressed, diarrhoea)
What are the two types of leishmaniasis and give features of each
Visceral - affects internal organs
BLACK FEVER: irregular fever, hepatosplenomegaly, weight loss
Cutaneous (e.g. localised cutaneous) - crusted lesions/scars
Worsened with HIV co-infection
What is hypersensitivity?
Tissue damaging immune responses mounted against harmless foreign antigens, autoantigens or alloantigens
Give the 4 types of hypersensitivity, with mechanisms and examples of each
Type I = immediate, IgE mediated. Need sensitisation - primary exposure to form IgE. Then secondary exposure antigen can cross link IgE -> mast cell degranulation, eosinophil and basophil recruitment. An aphylaxis, asthma, rhinitis, food allergy
Type 2 = Ab-dependent cytotoxicity. Tissue damage. e.g. Pernicious anemia. Hemolytic anemia.
Type 3 = Immune complex. Antigen-antibody complexes form in blood - deposition in tissue. Complement, cell activation/recruitment, activation of other cascades Causes vasculitis. SLE
Type 4= T-cell, delayed. Transient/persistent antigen causes T cell activation of macrophages, CTLs causes tissue damage - dependant on TNF alpha. Th1 or CTLs release TNFa. Contact dermatitis, chronic graft rejection
What are 6 ways in which pathogenic infections can contribute to the onset of autoimmune disease?
- Molecular mimicry of self molecules
- Induce changes in the expression and recognition of self proteins
- Induction of costimulatory molecules or inappropriate MHC class II expression: pro-inflammatory environment
- Effects on regulatory T-cells (failure of regulation)
- Immune deviation: shift in type of immune response e.g. Th1-Th2
- Tissue damage at immunologically privileged sites
A man presents with your surgery with a raised haematocrit and Hb. He is a smoker. Imaging shows a mass in his right kidney. List 4 possible causes for his raised Hb and haematocrit.
Renal tumour secreting erythropoeitin
Blood doping
Polycythaemia vera
Pseudo-polycythaemia (reduced plasma volume)
Increased EPO due to hypoxia (CO in smoke binds to Hb, O2 binding availability decreased, kidney secretes more EPO)
A man presents with your surgery with a raised haematocrit and Hb. He is a smoker. Imaging shows a mass in his right kidney. List 4 possible causes for his raised Hb/Hct and their mechanisms.
Renal tumour secreting EPO
Blood doping
Polycythaemia vera - bone marrow disorder producing too many red cells regardless of EPO
Increased EPO due to hypoxia (CO in smoke binds to Hb, O2 binding availability decreased, kidney secretes more EPO)
Pseudo-polycythaemia (reduced plasma volume)
Give 5 causes of normocytic normochromic anaemia
- Recent blood loss
- Early IDA/ACD
- Renal failure (low EPO)
- Bone marrow failure
- Hypersplenism - pooling of RBCs