4/9 - UWorld Flashcards
What is haptoglobin and what process is it involved in?
Haptoglobin is the protein that binds hemoglobin released during intravascular hemolysis in order to deliver Hb to the spleen
What is formed by the urogenital folds in females and males
Female - non-fusion forms labia minora
Male - fusion forms ventral aspect of the penis
What is formed by the labioscrotal folds in females and males
Females - labia majora
Males - scrotum
What is the triad associated with disseminated gonorrheal infection?
Arthritis, dermatitis, tenosynovitis
What is the mechanism of action of IgA?
IgA antibodies usually bind to pili and other membrane proteins involved in bacterial adherence to mucosa, thus inhibiting mucosal colonization by the microorganism
What is the function of staphylococcal protein A?
It binds the Fc portion of IgG, preventing complement fixation
What hormone is responsible for suppression of lactation in pregnant women?
Progesterone
What structures are resposible for progesterone production during pregnancy
Corpus luteum in first trimester
Placent in second and third trimesters
What structures are responsible for b-hCG production?
Syncytiotrophoblasts
b-hCG functions to maintain corpus luteum until placenta takes over for estrogen and progesterone synthesis
b-hCG reaches highest levels at 9 weeks, and then drops to very low levels once corpus luteum degenerates
What enzyme will take over fructose metabolism in fructokinase deficiency (essential fructosuria)?
Hexokinase
What is the deficient enzyme in fructose intolerance?
Aldolase B
HMO (health maintenence organization) vs. PPO (preferred provider organization) vs. POS (point of service)
Which has lowest monthly premiums, requires PCP referral, allows outside provider network?
Will methylmalonic acid be increased or decreased in B12 deficiency?
Increased
Methylmalonic acid is converted to Succinyl CoA using B12 as a cofactor
C1 inhibitor deficiency causes inappropriate activation of complement cascade and …. ?
Increased bradkinin
C1 inhibitor blocks kallikrein-induced conversion of kininogen to bradykinin
What are Langhan cells and what are the the result of?
Activated macrophages (epithelioid cells) can form Langhans giant cells, which characteristically have multiple nuceli organized peripherally in the shape of a horseshoe
These cells are a non-specific finding in granulomatous conditions (e.g. tuberculosis)
The macrophages are originally stimulated by CD4+ Th1 cells
What type of anemia will be seen in lead poisoning?
Microcytic anemia
Lead inhibits the heme synthesis pathway due to defective protoporphyrin synthesis (sideroblastic anemia)
What are common clinical findings of lead poisoning?
GI (abd pain, constipation, anorexia)
Neuro (cognitive defects, peripheral neuropathy)
Hematologic (anemia)
What will be seen in peripheral blood smear vs. bone marrow in lead poisoning
Bone marrow - ring sideroblasts
Peripheral blood smear - basophilic stippling
Describe the clinical presentation of congenital hypothyroidism
Lethargy, hoarse cry, poor feeding, constipation, jaundice, dry skin, large fontanelle, umbilical hernia, edema
Congenital hypothyroidism is one of the most common causes of preventable intellectual disability
Aka Cretinism (6 P’s):
Pot-bellied, pale, puffy-faced child with protruding umbilicus, protuberant tongue, and poor brain development
What is the defect in osteogenesis imperfecta?
Defect in type I collagen synthesis
What is a common mutation leading to osteopetrosis?
Carbonic anyhdrase II mutation
Leads to loss of acidic environment necessary for bone resorption
Describe lab findings in Paget disease of the bone (calcium, phosphate, PTH, alkaline phosphatase)
Isolated elevated alkaline phosphatase (due to end stage where osteoblasts are trying to lay down bone)
All other levels will be normal
Complications of Paget’s disease
High output cardiac failure (due to increased blood flow from formation of arteriovenous shunts in bone)
Osteosarcoma (end-stage osteoblasts at risk for mutation)
Features of Gardner syndrome
Familial adenomatous polyps
Osteomas/soft tissue tumors (osteoma of facial bone)
Impacted/supernumerary teeth
