Pastest 3 Flashcards
Which envelope proteins on the surface of HIV virus enable it to get into cells?
GP120 binds to primary receptor (CD4 molecule)
GP41 mediates movement through the cell membrane
How long does it take for HIV to become AIDs?
5-10 years
How does mefloquine toxicity present?
Acute psychosis
What does bartonella henselae cause?
Cat scratch disease
Which serological marker most strongly confirms recent acute hepatitis B infection?
Anti-HBC IgM
HbsAg often disappears by the time patients are jaundiced, and is present in acute and chronic
What is Jo1 syndrome?
Polymyositis + interstitial lung disease
When is methotrexate used in SLE?
If arthritis is present
What are the causes of death in PAN?
Renal failure
Bowel obstruction or perforation
Cardiovascular causes
(does not affect the pulmonary arteries)
What are the features of thoracic outlet syndrome?
Disappearance of arm pulse when raised above head
Pain, numbness and tingling
What are the characteristics of scleroderma renal crisis?
Malignant hypertension
Rapid renal impairment
Onion skin intrarenal vasculature
More common in diffuse systemic sclerosis
How is bronchiolitis obliterans diagnosed?
Irreversible obstructive picture
CT: bronchial wall thickening and air trapping
What is the cause of hypoxia in primary pulmonary hypertension?
Intra-pulmonary shunting
Reduced diffusion capacity secondary to arterial fibromuscular dysplasia
How does sleep apnoea lead to cor pulmonale?
Chronic nocturnal hypoxia –> pulmonary artery vasoconstriction –> secondary pulmonary hypertension
What are the causes of primary pulmonary hypertension?
Plexogenic pulmonary arteriopathy
Chromosome 2
What type of arthritis can worsen in the post-operative period?
Crico-arytenoid arthritis
Causes stridor
What are the causes of type 2 membranoproliferative glomerulonephritis?
Partial lipodystrophy
Factor H deficiency
Measles
What can acute kidney rejection be confused for?
Post-transplant lymphoproliferative disorder
Polyomavirus BK virus
What are the two types of acute kidney transplant rejection?
Cell mediated
Antibody mediated
What are the criteria for diagnosis of antibody mediated acute kidney transplant rejection?
Graft dysfunction
Histological evidence of tissue injury
Positive staining for C4d
Presence of donor specific antibody
What medications are given during kidney transplant surgery?
1g methylprednisolone
Anti-CD25 monoclonal antibody e.g. basiliximab
Which antibodies are involved in acute kidney transplant rejection?
IgG
What is the WAGR triad?
Wilms’ tumour
Aniridia
Genitourinary problems
LD
What are the causes of normal anion gap metabolic acidosis?
CAT MUDPILES
Cyanide poisoning Aminoglycosides Toluene Methanol Uraemia DKA Paracetamol Isoniazid Lactic acid Ethanol Salicylates
Which type of nephropathy is caused by underlying malignancy in 10%?
Membranous
What are Bartter and Gitelman syndromes?
Bartter - kidneys cannot reabsorb chloride in the thick ascending limb of the Loop of Henle
Gitelman - kidneys cannot reabsorb chloride in the distal convoluted tubule
When are Bartter and Gitelman syndromes diagnosed?
Bartter - childhood
Gitelman - later
What is disequilibrium syndrome?
Cerebral oedema caused by rapid shifts of uraemic toxins, associated with too-rapid haemodialysis
What type of antibody deficiency is associated with infection with polysaccharide coated organisms?
IgG2
What investigation confirms hyperaldosteronism?
Saline suppression test
But often hypertension, hypokalaemia, and raised aldosterone are adequate for diagnosis.
When is oral aciclovir given in chickenpox?
Adults presenting within 72h onset
Pregnancy/immunocompromised
What are the features of Sweet’s syndrome?
Associated with myelodysplastic disorders
Plum coloured lesions, mucosal involvement
Neutrophilia and fever
How does lorazepam enhance the effects of anti-emetics?
GABA-A modulator
Increases the opening frequency of GABA activated chloride channels
What are the characteristics of disseminated mycobacterium avium complex?
Occurs in pts with CD4 <50
Fever + night sweats
Diarrhoea and weight loss
Hepatomegaly and lymphadenopathy
How effective is the BCG vaccine at preventing severe TB?
70-80%
What is the treatment of syphilis?
IM Procaine penicillin/benzathine penicillin
Pen allergic - azithromycin
When should you suspect alpha thalassaemia?
Microcytic anaemia
Normal/raised ferritin
How is methanol metabolised?
By alcohol dehydrogenase to formaldehyde
What are indications of haemodialysis in methanol poisoning?
Methanol concentration >50mg/dL Visual disturbance/CNS toxicity Severe metabolic acidosis Severe electrolyte imbalance Renal failure Deterioration despite initial treatment with fomepizole/ethanol
How does heparin cause hyperkalaemia?
Inhibits aldosterone secretion
leads to impaired renal potassium secretion
Particularly in patients who are diabetic or acidotic
What receptor increases response to chemotherapy if expressed on cancer cells?
P-glycoprotein
How does HCOM compare to aortic stenosis?
Similar symptoms and signs
Jerky pulse in HCOM
Valsalva increases intensity of murmur in HCOM and decreases murmur in aortic stenosis
Which cytotoxic agent is used in colorectal carcinoma?
5-fluoruracil