Block 9 key things to learn Flashcards
What are the layers of the epidermis from outside to in?
Stratum corner Stratum lucidum- only in thick skin Stratum Granulosum Stratum spinous Stratum basale
What cells are in the epidermis?
Keratinocytes- produce keratin
Melanocytes- pigment
Langerhans cells- APC
Merkel cells in basal layer- fine touch sensation
What are the 3 different skin glands?
Sebaceous- secrete sebum, branched acinar structure
Eccrine- secrete sweat, coiled tubular glands
Apocrine- only found in axilla, groin and mammary areas, Secrete viscous cloudy secretion- active from puberty- BO
What are the different types of hypersensitivity reactions?
Type 1- IgE mediated- mast cell activation- asthma
Type 2- IgG mediated, complement and antibodies involved- drug allergies
Type 3- immune complexes- serum sickness
Type 4- T cell mediated- Contact dermatitis
Give some examples of different virus types?
Positive SSRNA viruses- influenza, mumps, rabies, measles
Negative SSRNA viruses- polio, dengue, Hep C
DSRNA viruses- Rotavirus
What degrades P53 after all DNA is repaired?
MCM2
What is xeroderma Pigmentosum?
Mutation in NER system of UV damage. Causes extreme sensitivity to light and huge increased skin cancer risk
What are the different types of radiotherapy?
Conventional external beam radiation- traditional 2d beams, high dose treatment limited by damage to surrounding tissues
Sterotactic radiation- more focused radiation due to use of detailed image scans- more radiation delivered quicker just to tumour
Particle radiation- energised particles directed at tumour- more focused
Brachytherapy- radiation source place in/ near area needing treatment so can give higher and quicker doses locally
What are the modes of resistance of anti-cancer drugs?
Change in sensitivity or binding affinity of target enzymes or receptors- etoposide, methotrexate
Decreased drug accumulation- methotrexate, dactinomycin, alkylating agents
Formation of drug inactivating enzymes- purine and pyrimidine antimetabolites
Production of reactive chemicals that trap the drugs- bleomycin, cisplatin, doxorubicin
Increased nucleic acid repair mechanisms- alkylating agents, cisplatin
Reduced activation of pro drugs- purine and pyrimidine antimetabolites
Increased expression of MDR1 gene involved in drug efflux- verapamil, quinidine, cyclosporine
What new drug is used if resistant to gefinitib?
Resistance due to T790M mutation
Rocilentinib
What is the malaria life cycle?
Mosquito bites and transmits sporozoite to human
Liver cells get infected and sporozoites mature into schizonts
Schizonts then rupture and release merozoites which infect red blood cells
Some merozoites develop into immature gametocytes
Another mosquito bites and consumes the immature gametocytes
Gametocytes create zygotes in mosquito stomach
Zygotes mature to oocysts and release sporozoites into mosquito saliva to start cycle again
What are the antigen tests for yeast and mould?
Yeast- beta gluten
Mould- gallactomann
Name some mycoses?
Superficial mycoses- tinea versicolour - lightening affect on skin, no immune response
Cutaenous mycoses- Ringworm and candiadiis- deeper into epidermis, immune system may be involved
Subcutaenous mycoses- involves dermis, muscles etc.
Deep mycoses- nucor
Systemic mycoses- candiadis in immunocompromised or aspergillum
What are the key antifungals?
Amphotericin B- binds with ergosterol in cell membrane to create pores so contents leak and die. Very broad and toxic- renal damage.
Azoles- inhibit lanosterol demethylase needed to covert lanosterol to ergosterol. More targeted and less toxic than amphotericin
Echocandins- inhibit synthesis of gluten in cell wall mostly used for systemic infections. e.g. caspofungin
What are the key parasite infections?
Sleeping sickness/ African trypanosomiasis- trypanosome Bruce from tsetse fly
Chagas disease/ South American trypanosomiasis- trypanosome Cruzi- faecal oral or blood transmission
Leishmaniasis- leishmania from sandflies
