USMLE questions Flashcards
how is glioblastoma characterised on CT
serpentine border and central areas of necrosis
Densely packed cells with halos of cytoplasm surrounding large
round nuclei are characteristic of
oligodendrogliomas
Sharply demarcated areas of tumor cells located at the grey-white
matter junction are characteristic of
secondary metastatic lesions from a primary tumor elsewhere
in the body, most commonly the breast, lung, thyroid, skin, kidney, and gastrointestinal tract.
CT head: A whorled pattern of concentrically arranged spindle cells with calcified psammoma bodies is characteristic of
meningiomas
conditions with psammoma bodies on histology
papillary thyroid cancer
serous cystadenoma of ovary
meningioma
mesiothilioma
difinitive test to diagnose parkinsons
alpha- synuclein immunostaining
describe huntingtons disease
autosomal dominant
anticipation of CAG repeat
atrophy of the caudate nucleus
chorea and dementia are key features
kidney findings and risks in turners
horseshoe kidney
pelvic kidney
duplicated collecting systems
increased risk of wilms tumour compared to general population
biggest risk factor for transitional cell carcinoma and squamous cell carcinoma of the kindey respectively
TCC –> smoking
SCC –> schistosomiasis infection
macrophages engulfing RBCs on blood film is characteristic of what
haemophagocytic lymphoschistocytosis
complication of septic shock in kidney and describe it
diffuse cortical necrosis
combination of hypoperfusion, microangiopathic thrombosis, and infarction; thromboses may be present in the arterioles, capillaries, and glomeruli. The areas of necrosis are generally confi ned to the cortex and, on gross examination, are sharply demarcated
extracolonic cancer risks of lynch syndrome
endometrial, ovarian, urinary tract, stomach
which chromosomes is the mutation found in the following conditions
adult PCKD
recessive PCKD
von hippen lindau syndrome
tuberous sclerosis
adult PCKD - chrom 16
recessive PCKD - chrom 6
von hippen lindau syndrome- chrom 3
tuberous sclerosis- chrom 9
clinical and lab findings in DMD
X linked recessive
Symptoms become evident by the age of 5 years and include delayed walking, clumsiness, weakness in the pelvic girdle muscles, and enlargement of the calf muscles
elevated CK
mutation on Xp21 gene encoding dystrophin
what is deficient in phenylketonuria and what are the features?
phenylalanine hydroxylase
catalyses the conversion of phenylanaline to tyrosine
characterized by problems with brain development, mental retardation, and seizures.
what does absence of spectrin lead to
hereditary sperocytosis
what sort of virus is EBV
DNA virus
member of the human herpes virus family (HHV4)
‘owl eyes’
round intranuclear inclusion with perinuclear halo seen in cells affected by
CMV
effects of CMV on immunocompromised
retinitis
pneumonitis
inflammation of GI tract
polyradiculopathy
transverse myelitis
focal encephalopathy
complications of MI
rupture of the ventricular free wall –> tamponade 4-10days (sudden shock with signs of cardiac tamponade, such as the hypotension, distant heart sounds, and elevated jugular venous pressure )
aneurysm due to lack of contractility i infarcted area
arrhythmias - first few days after
fibrinous pericarditis 3-5 days
(chest pain that is relieved when the patient leans forward; often a pericardial friction rub can be auscultated on cardiac examination)
dresslers syndrome- weeks after
papillary muscle rupture 4-10 dys after (acute mitral regurgitation, causing the abrupt onset of heart failure in the setting of a new systolic murmur)
how to differentiate between staphaureus colonisation and staphylococcal colonisation of microflora
coagulase test
staph aureus - coagulase positive
staph epidermidis - coagulase negative
which infection is associated with honey
clostridium botulinum
example of a species with a non immunogenic capsule
strep pyogenes with a hyaluronic capsule
what bacterial species is an unusual obligate intracellular pathogen due to its inability to synthesise ATP
chlamydia
triad of
cutaneous hemorrhages (“blueberry muffin baby”), deafness, and periventricular CNS calcifications suggestive of…
congenital CMV infection
what organism can cause potentially fatal granulomas (granulomatis infantiseptica) following in utero infection.
listeria monocytogens
most common site for aspiration pneumonia
apical segment of the lower lobe (typically right)
where is the porphyrin ring of haem derived from? (start of haem synthesis)
succinyl-CoA and glycine
catalysed by aminolevolinic acid (ALA) synthase to produce ALA
accumulation of chylomicron reminants is characteristic of which fmilial cholesterol disorder
familial type III hyperlipidaemia (familial dysbetalipoproteinaemia)
features of vitamin A deficiency
drying of the bulbar conjunctiva (xerosis) and blind spots (small, grey plaques on the conjunctiva)
features of vitamin E deficiency
areflexia, decreased proprioception and vibration sence, gait disturbances and paresis of gaze
what deficiency makes you more susceptable to anaphylactic blood transfusion reaction
selective IgA deficiency
features classically associated with wiskott aldrich syndrome
recurrent infections, eczema and thrombocytopenia
which cell surface marker is required for lysis of IgG coated cells by NK cells
CD16
common causative organism of pneumonia in alcoholics and describe the microbiological features
klebsiella pneumonia
gram negative rod
which strep species are alpha and beta haemolytic
alpha haemolytic - strep viridans, strep pneumoniae
beta haemolytic- strep pyogenes (GAS) , strep agalactiae (GBS)
which cocci are catalase neg and which are catalase positive
streptococcus- catalase negative
staph- catalase posititve
which organisms are coagulase positive and which are negative
positive- staph aureus, yersiniapestis
negative- strep pyogenes, staph epidermidis
which interleukin has a direct effect on the hypothalamus to induse fever
IL-1 produced by macrophages
gram positive rod found in the upper respiratory tract and skin
diptheria
what antibiotic taken by mother causes teeth motteling to baby in utero
tetracyclines
classic findings on clinical examination in ASD
(atrial septal defect)
prominent right ventricular cardiac impulse
systolic ejection murmur heard loudest in pulmonary area, left sternal border
fixed splitting of second heart sound
sunburst appearance on xray and codmans triangle is characteristic of what
osteosarcoma
is bicarbonate usually high or low in hyperaldosteronism and what is the mechanism
high
aldosterone stimulates excretion of H+ in distal tubule creating a metabolic alkalosis (high HCO3)
????? needs clarification
what is Bernard-Soulier syndrome?
autosomal recessive condition of faulty platelet adhesion
prolonged bleeding time in the presence of a normal plt count
dysfunction of gp Ib-IX complex
previously fit and well person in 20s develops painful muscle cramps after strenuous exercise. urine turns red
classic clinical picture of what glycogen storage disease
McArdle syndrome
red urine casued by myoglobinurea
what does a,b and g haemolytic mean
refers to how much haemolysis of RBC occur in response to the bacteria
alpha haemolytic- partial haemolysis
beta haemolytic- complete haemolysis
gamma- no haemolysis
what are the mutated genes in MEN 1 and MEN2a/b
MEN 1- MEN1 gene
MEN2a/b - RET gene
If query CAH
Pt has hypertension, hypokalaemia and low sex hormones (ambiguous genitalia, delayed pruberty)
what enzyme deficiency are you thinking
17alpha hydroxylase def
If query CAH
pt has hypotension/ salt losing crisis and ambiguous genitalia in girls)
what enzyme def are you thinking?
21- hydroxylase def
