Misc Flashcards
HIV Brief pathophysiology, disease progression. Risk Symptoms Diagnosis Treatment
In sexual intercourse HIV virus infects locally dendritic/macrophage cells of the mucosa. These are antigen presenting and travel to the lymph to present to CD4 T helper cells. HIV binds to receptor and injects single stranded RNA into cell. Reverse transcriptase enzyme converts it to double stranded pro-viral DNA which is able to integrate into host cell DNA. Host cell then transcribes new virus, which buds off to infect new CD4+ cells. Infected T cells leave lymph node and spill out into blood - viraemia - and apoptose (numbers decrease as illness progresses). The immune system attacks and HIV enters latent phase where numbers of T cells are decreasing but still able to fight infection. When low enough, early symptoms begin. When T cell count is <200 T cells/mm3 this is called AIDS. AIDS defining illnesses will also be present.
Risk:
Unprotected sex: anal sex spreads most efficiently, men most affected
IVDU
Sex workers and customers
Symptoms:
During acute infection when viraemia ensues flu-like symptoms are present (weight loss, fever, malaise, myalgia, pharyngitis, rash).
Latent phase usually asymptomatic, 30% lymphadenopathy.
Early symptomatic (200-500 T cells/mm3) wi;; have lymphadenopathy, night sweats, diarrhoea, fever, weight loss as well is mild infections: oral candidiasis, herpes zoster, recurrent herpes simplex
AIDs defining illness:
- recurrent bacterial pneumonia
- pneumocystis pneumonia (caused by Pneumocystis jirovecii fungus)
- candidiasis of oesophagus/lung
- CMV (cytomegalovirus)
- mycobacterium TB
- tumours: kaposi sarcoma, primary lymphoma, non-hodgkin’s lymphoma
Diagnosis:
- Antibody test: IgG to HIV envelope contents
- Antibody/antigen test: IgG antibody to p24
Monitoring of CD4 T cell count and HIV viral load in RNA copies/ml is useful for prognosis
Treat:
HAART = highly active antiretroviral therapy
Consists of
2 nucleoside reverse transcriptase inhibitors + 1 non-nucleoside reverse transcriptase inhibitors
eg abacavir, didanosine + efravirenz
or
2 NRTI and one protease inhibitor
eg abacavir, didanosine + atazanavir
Despite suppression most individuals still have infection due to viral sanctuary sites, however
Breast cancer Main types Risk Presentation - likely differentials? Diagnosis Treatment
Ductal carcinoma in situ: epithelial cells of breast ducts proliferate, don’t invade BM
Invasive ductal carcinoma: ductal epithelial cells proliferate and invade to surrounding tissue
Can also have invasive and preinvasive lobular breast cancer, inflammatory breast cancer, Paget’s cancer of breast
risk:
female (1% male)
obesity
alcohol
oestrogen exposure - menarche (starts early ends late), oral contraceptive pill, HRT. Breastfeeding and parity protective.
Family history
BRCA1 & 2 genes
Presentation:
painless, increasing mass. May have skin tethering, nipple discharge, ulceration, oedema/erythema if inflammatory. In young people fibroadenoma is most common, breast cysts in older. Intraductal papilloma possible.
Diagnosis: ‘triple assessment’
1. History and examination
2. If <35, USS of breast. If over, USS and mammogram
3. Histology and cytology:
- fine needle aspiration
- core/punch biopsy
If confirmation, staging is done using CXR, MRI, CT, liver USS, bone scan, LFTs, Ca2+: common sites of mets are lymph, bone, liver, lung, brain
Treat
according to stage
according to individual preference and characteristics of the tumour
Local treatment options(surgery, radio), systemic treatment options (chemo, HER2) and others
stage 1/2 (confined to breast, lymph node)
surgery: wide local excision/mastectomy, axillary node clearance.
+ chemo: epirubicin + CMF (cyclophosphamide, methotrexate, flurouracil)
If post menopausal oestrogen positive = tamoxifen, pre menopausal = ovarian ablation, goserelin.
Stage 3/4 (3: fixed to muscle, lymph nodes matted/fixed, skin large involvement. 4: fixed to chest wall, distant metastases)
Radiotherapy to bone lesions - alendronate reduces fractures
Tamoxifen if oestrogen positive
Trastuzamab (herceptin) if HER2
