USMLE Step 1: Biochemistry & other
Biochemistry
Biochemistry
Set of flashcards Details
| Flashcards | 288 |
|---|---|
| Language | English |
| Category | Medical |
| Level | University |
| Created / Updated | 02.03.2015 / 27.03.2020 |
| Weblink |
https://card2brain.ch/box/usmle_step_1_biochemistry_other
|
| Embed |
<iframe src="https://card2brain.ch/box/usmle_step_1_biochemistry_other/embed" width="780" height="150" scrolling="no" frameborder="0"></iframe>
|
M. tuberculosis
IF-gamma, IL-12 & TNF-alpha are critical for the formation & maintenance of granuloma
Deficiency of the complement factors that form the membrane attack complex results in recurrent infections by...?
Neisseria species
poison ivy dermatitis
- form of allergic contact dermatitis
- type IV hypersensitivity mediated primarly by T-lymphocytes
Chronic granulomatous disease (CGD)
- most commonly due to an x-linked mutation affecting NADPH oxidase
- leads to an inability of neutrophils to form the oxidative burst necessary to kill organisms in their phagolysosomes
- diagnose: absence of normal blue & fluorescent green pigment produced by the nitroblue tetrazolium test & dihydrorhodamine flow cytometry test
Serum sickness
- type III hypersensitivity reaction to nonhuman proteins characterized by vasculitis resulting from tissue deposition of circulating immune complexes
- clinical findings: fever, pruritic rash, arthralgias, low serum C3 & C4 complement levels
Fas receptor
Initiates the extrinsic pathway of apoptosis
DiGeorge syndrome
- T-lymphocytic immunodeficiency
- maldevelopment of 3rd & 4th pharyngeal pouches
- deletion on chromosome 22
- clinic:
- absence of thymic shadow
- hypocalcemic tetany from absence of the parathyroids
- cleft palate
- madibular deformity
- low-set ears
- aortic arch abnormalities
Pulmonary tuberculosis infections controlled by which cells?
CD4+ TH1 & macrophages
Why does hemolytic disease not occur when the maternal blood type is A or B?
- because anti-A & -B are IgM, which cannot cross the placenta
- type 0 mothers –> antibodies mainly IgG –> can cross placenta –> fetal hemolysis
IF alpha & beta in response to viral infection
- act on neighboring cells: stimulate them to synthesize antiviral proteins that degrade intracellular mRNA & impair protein synthesis
presence of what greatly increases the risk of a vertical transmission of Hep B?
presence of HBeAG in mother
TGF-beta & IL-10
are thought to down-regulate local cytokine production & inflammatory reactions
IL-1, IL-4, IL-5, IL-12
- stimulate local immune reactions –> proinflammatory
- IL-1: acts systemically to promote fever
Ataxia telangiectasia: triad
- Triad
- cerebellar ataxia
- telangiectasis
- increased risk for sinopulmonary infections
- genetic defect in ATM gene –> DNA break repair
- immune deficiency –> primarily IgA –> recurrent sinopulmonary & GIT infections
Selective IgA deficiency: associated with?
anaphylactic response to transfused blood products
Rheumatoid factor
IgM antibody specific for the Fc component of self IgG
SCID
combined T & B cell dysfunction
Leukocyte adhesion deficiency
- results from the autosomal recessive genetic absence of CD18
- inability to synthesize integrins
Major prevention of reinfection with influenza virus
anti-hemagglutinin IgG antibodies in circulation & mucosal anti-hemagglutinin IgA antibodies in the nasopharynx
Chédiak-Higashi syndrome
- autosomal recessive
- disorder of neutrophil phagosome lysosome fusion that results in neurologic abnormalities, partial albinism & immunodeficiency
Uric acid stones
only radiolucent stones
What is pancreatic islet amyloid deposition charateristic for?
DM type 2
Polyarteriitis is associated with what viral infection?
Hep B
Psoas sign
Pain when hip is extended –> inflammation
Adeno-Ca of the pancreas
- clinical presentation
- RF
- courvoisier sign, weight loss, jaundice
- RF
- Age
- Smoking
- DM
- chronic pancreatitis
- genetic predisposition
Aplastic anemia: clinical presentation
- pancytopenia
- low reticulocyte count
- absent splenomegaly
- dry bone marrow aspiration
M. Tuberculosis infection: what type of hypersensitivity reaction?
type IV delayed-type hypersensitivity reaction
Colitis-associated colon-ca
- more likely to arise from non-polypoid dysplastic lesions
- multifocal in nature
- develop early p53 mutations & late APC gene mutations
- are of a higher histological grade
Dermatitis herpetiformis strongly associated with what?
Celiac disease
Monoclonal lymphocyte proliferation is a strong evidence of what?
Malignancy
Most common renal malignancy
- clear cell ca
- arises from renal tubular cells
- high glycogen & lipid accumulation
abnormal bleeding in patient with uremia due to qualitative platelet disorder
- PTT?
- Platelet count?
- aPTT
- normal
- normal
- normal
Lacunar infarcts
most often due to hypertensive arteriolosclerosis of small, penetrating arterioles
Rupture of apical subpleural blebs
most common cause of primary spontaneous pneumothorax
Extended consumption (>3 mo) of appetite suppressants is associated with what?
increased incidence of pulm. hypertension
vWF disease
most common inherited bleeding disorder
Treatment of hemophilia A
Desmopressin: releases vWF & factor VIII from the endothelium
Synaptophysin: stain for what?
CNS tumors
GFAP: stain for what?
Glia tumors
PCOS: increased risk for which malignancy?
increased risk for endometrial adeno-ca
