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 -2  (nbme20#36)

c peptide = endogenous insulin , low c peptide + low blood glucose = exogenous insulin. very simple

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submitted by hayayah(883),

Sensitivity tests are used for screening. Specificity tests are used for confirmation after positive screenings.

Sensitivity tests are used for seeing how many people truly have the disease. Specificity tests are for those who do not have the disease.

A highly sensitive test, when negative, rules OUT disease. A highly specific test, when positive, rules IN disease. So, a test with with low sensitivity cannot rule out a disease. A test with low specificity can't rule in disease.

The doctor and patient want to screen for colon cancer and rule it out. The doctor would want a test with high sensitivity to be able to do that. He knows that testing her stool for blood will not rule out the possibility of colon CA.

sympathetikey  SeN Out (Snout) --> sensitive test; - test rules out SPec In (Specin) --> specific test; + test rules in +3  
usmlecrasher  can anyone pls explain why it is not << potential false- positive results >> ??? +  
almondbreeze  correct me if I'm wrong, but 'high FP (choice C)=low specificity (choice B)'. Whereas high specificity is required to rule in dz +1  
almondbreeze  picked positive predictive value myself. can anyone explain why not PPV? +  
williamfreakingosler  The principle @hayayah is talking about (a negative test being relied upon to reliably rule out) is negative predictive value ("NPV"). I don't see why "uncertain NPV" isn't the correct answer, particularly because NPV is predicated on the disease having the same base rate in the person(s) being tested as in the population that was characterized for the test statistic. Given that the patient has a strong family history of colon cancer, the NPV of FOBT is uncertain. Said another way, the sensitivity of a test does not change with the population, but the NPV does. The whole reason the doctor is denying FOBT is because of bayesian thinking (a priori information related to family history), and from my point of view bayesian logic is more relevant to PPV/NPV than to sensitivity, hence my confusion over why NPV isn't the right answer. +2  
ibestalkinyo  I thought negative predictive value for the same reasoning +  

submitted by hayayah(883),

GnRH agonists like Leuprolide are effective for patients with breast CA because if given in a continuous fashion, they downregulate the GnRH receptor in the pituitary and ultimately decrease FSH and LH.

md_caffeiner  Quick question: FA19 691 says Leuprolide ClINICAl USE is Uterine fibroids, endometriosis, precocious puberty, prostate cancer, infertility... I guess all except infetility(pulsatile?) are used as continuous? +1  
usmlecrasher  GnRH is synthesized and released in pulsatile fashion , so if you give in pulsatile way you induce GnRH effect , and if given in continuous way it will suppress synthesis, depended the desired effect you want to achieve - infertility induce GnRH with pulsatile , stop synthesis for prostate cancer , testicular cancer , hormone dependent Breast cancer give continuous +1  

submitted by celeste(62),

While the lifetime risk in the general population is just below 1%, it is 6.5% in first-degree relatives of patients and it rises to more than 40% in monozygotic twins of affected people. Analyzing classic studies of the genetics of schizophrenia done as early as in 1930s, Fischer concludes that a concordance rate for psychosis of about 50% in monozygotic twins seems to be a realistic estimate, which is significantly higher than that in dizygotic twins of about 10–19% (ncbi.nlm.nih.gov/pmc/articles/PMC4623659/#ref3)

imnotarobotbut  How is one supposed to know this before having read this article? +15  
imgdoc  This question falls under the either you know it or you dont category. It isnt in FA or Uworld +  
jaxx  So why would these A-holes put it on there as if prepping for this exam isn't stressful enough :-| +5  
doodimoodi  Lol just why seriously +2  
champagnesupernova3  This was mentioned in the Kaplan behavioral videos +  
usmlecrasher  and there's so much unnecessarily BS instead of real questions +1  

submitted by hayayah(883),

It's transitional cell carcinoma, which smoking is a common risk factor for; it can involve the renal pelvis/calyces. The histo image shows the papillary nature of the tumor (however it can also be flat or nodular according to Pathoma).

Also known as urothelial carcinoma. Most common tumor of urinary tract system (can occur in renal calyces, renal pelvis, ureters, and bladder). Can be suggested by painless hematuria (no casts).

usmlecrasher  i'm sorry guys it's bladder cancer blocking urine flow => reflux ureteral widening => reflux nephropathy. +2  
hello_planet  FA 2019 pg 588 +  

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