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 +6  (nbme23#30)

SLE is associated with deficiency of early complement proteins(eg. C1q, C4, C2). (FA 19, pg. 462)

tinydoc  Am I the only one who has never heard of C1Q?
llamastep1  I knew SLE is related to low complement but when it talked about a "mutation" it threw me off.

 +1  (nbme23#47)

According to Goljan, polycythemia vera is one of the most common causes of Budd-Chiari syndrome. According to FA, Budd-Chiari is associated more generally with hypercoagulable states, polycythemia vera, postpartum states, and HCC.

Hepatic cirrhosis can be ruled out based on the time course of the patient's presentation - he was fine 2 weeks ago and the abdominal pain started an hour ago.

krewfoo99  Also in cirrhosis, the liver wont be enlarged or tender on palpation
almondbreeze  @krewfoo99 Good job. accoring to FA2019 pg.368, congestive liver disease (hepatomegaly, ascites, varices, abdominal pain, liver failiure) seems to be the key in Budd-Chiari SD

 +5  (nbme23#20)

Remember on histology Hashimoto's thyroiditis has two distinct features Hürthle cells(which are eosinophilic metaplastic cells that line follicles) and lymphoid aggregates with germinal centers.(pg. 338, FA 2019) The correct answer describes the latter feature of Hashimoto's.

 +0  (nbme23#39)

Celiac sprue is a malabsorption syndrome that results in steatorrhea and results in iron deficiency anemia. As far as I'm aware, none of the others result in iron deficiency anemia. (I had Bacterial overgrowth as a close second but I don't believe that's associated with iron deficiency).

yb_26  bacterial overgrowth is associated with iron deficiency, but also with Vit B12-deficiency, so I guess pts will have macrocytic anemia
nor16  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3099351/. Vit B12 is key here, moreover, no bloating (IBS and bacterial overgrowth with bloating). bacterial overgrowth is a close one!

 +6  (nbme23#4)

The definition of Decision-Making Capacity according to B+B is ability to comprehend information about illness and treatment options and make choices in keeping with personal values.

notadoctor  The decision must also remain stable over time, which is the "consistent values" part of the answer.

 +2  (nbme23#45)

I've been searching for my source for this but can't seem to find it. However, the way I thought about it was that edema happens via the capillaries. If there is increased resistance via the precapillary sphincters as much blood wouldn't be able to get into the capillaries. The blood would instead get shunted via anastomoses to the veins. This article from cvphysiology.com explains it a little better: CV Physiology: Tissue Edema and General Principles of Transcapillary Fluid Exchange

 +0  (nbme21#6)

This question was asking about the adverse effects of proton pump inhibitors especially given previous kidney issues. PPIs decrease serum Mg and serum Ca absorption and can increase the risk of fracture (especially in the elderly).

yotsubato  PPI therapy *begins* the day she presents. She has not taken PPI before
notadoctor  You're right, I missed that!
naught  MEN 1 is pituitary (monitor cortisol), pancreas, parathyroid (monitor calcium) but is not the ask of this question.

 +10  (nbme21#36)

If you were stuck between Chondrosarcoma(malignant) and Enchondroma(benign) remember enchondromas may erode the cortex but can never invade/disrupt the cortex. I think this was the distinction the question was testing.

 +24  (nbme21#32)

Usual interstitial pneumonitis is the histological definition of Idiopathic pulmonary fibrosis. We know that this patient has pulmonary fibrosis because the question states that there is fibrous thickening of the alveolar septa. This question was just testing that we knew the other names for Pulmonary Fibrosis.

aneurysmclip  Nbme back at it again
pg32  Is it still considered idiopathic pulmonary fibrosis is it appears to have been caused by an atypical pneumonia?

 +6  (nbme22#27)

Metastatic disease is more common than primary bone tumors.

 +6  (nbme20#29)

Analysis of the elastin in the question showed a decreased number of desmosine cross-links. Desmosine is made up of four lysine residues. Therefore abnormal elastin is likely missing lysine necessary for the formation of these desmosine cross-links. Wikipedia article on Desmosine.

dbg  how can i trust you, you aint even a doctor
euchromatin69  trust this then U.W 1249
tryntofigritout  UW 1249 was perfect. #loveyourname euchromatin ha

Subcomments ...

submitted by lsmarshall(267),

Urea Cycle Disorders > Isolated severe hyperammonemia (> 1000; i.e., no other severe metabolic disturbances

Ornithine transcarbamylase deficiency > (most common urea cycle dis.) orotic acidemia/aciduria, hyperammonemia

Organic Acidemias > Hyperammonemia, anion-gap acidosis, ketosis (from hypoglycemia)

Medium-chain acyl-CoA dehydrogenase deficiency > Hyperammonemia, hypoketotic hypoglycemia (seen in β-oxidation disorders, EXCEPT adrenoleukodystrophy)

Liver dysfunction > Hyperammonemia, LFTs messed up, older pt.

lsmarshall  Summary of metabolic issues relating to hyperammonemia +4  
seagull  i'm leaning towards Ornithine transcarbamylase deficiency. +2  
notadoctor  Not sure why this isn't considered a mitochondrial disorder since the issue is Ornithine transcarbamylase deficiency in the mitochondria? +2  
charcot_bouchard  if it was mitochondrial disorder no one would escape +1  
wowo  figure in OTC deficiency, they might have to explicitly mention the orotic aciduria AND typically presents earlier, around 24-48hrs of life after they've fed (at least per BB) + also per BB, propionic acidemia and MM acidemia have an onset of weeks to months and lead to build up of organic acids --> acidemia in addition to hyperammonemia (not sure why, but several aa enter the TCA cycle via propionyl CoA --> methylmalonyl CoA --> succinyl CoA, but now this is defunct d/t enzyme deficiencies...?). Anywho, propionic acidemia described on FA2019 p85, but doesn't list hyperammonemia +2  
artist90  i think it cannot be Ornithine transcarbamylase deficiency bc it is XR disease. this pt has a healthy 2yr old brother which rules out X-linked recessive disease correct me if i m wrong +1  
artist90  it is 100% Propionic acidemia Uworld Q-id: 1340. it is an exact copy question of uworld. i got it wrong bc i forgot these are organic acids. But i am still confused on 2 things 1-how does acidosis cause Hypoglycemia and Ketosis. 2-why is Ammonia elevated in these pts bc urea cycle will be fine? +  
yb_26  1) hyperammonemia is seen in all urea cycle disorders except arginase deficiency 2) organic acids directly inhibit urea cycle => hyperammonemia (from UWorld) +1  
yex  According to UW, there is another question # 1341. This one refers to methylmalonic acidemia (ORGANIC ACIDEMIA). HYPOGLYCEMIA results from overall increased metabolic rate leading to increased glucose utilization and direct toxic (-) of gluconeogenesis by organic acids. The presence of hypoglycemia leads to increased free fatty acid metabolism that produces KETONES, resulting in a further anion gap met acidocis. Finally, organic acids also directly (-) the urea cycle, leading to HYPERAMMONEMIA. +6  

submitted by sajaqua1(347),

Gynecomastia, spider angiomata, and hypogonadism (as well as palmar erythema) are all signs of excess estrogen. The liver in patients with hepatic disease is impaired and so cannot clear estrogen sufficiently. Six 12 oz beers daily (72 oz, or half a gallon) is too much, and is destroying his liver.

uslme123  No hepatosplenomegaly, ascites, or edema through me off. We that being said, I shied away from cirrhosis. I thought that he showed signed of depression, so I went with the thyroid. But who's to say he isn't injection anabolic steroids?! +1  
catch-22  The principle is you can get liver dysfunction without having HSM, ascites, etc. Liver disease is on a progressive spectrum. +6  
notadoctor  He likely has hepatitis B/C given his history of intravenous drug use. I believe both can have liver dysfunction but may or may not have ascites, whereas the type of damage we would expect from alcohol that would match this presentation would also show ascites. +  
charcot_bouchard  For Ascities u need to have portal HTN. Thats a must. (unless exudative cause like Malignancy) +1  
paulkarr  For anyone who needs it; the FA photo is kinda burned into my mind for these questions. NBME has some weird infatuation with this clinical presentation.. FA (2019) Pg: 383 "Cirrhosis and Portal HTN". +1  

submitted by notadoctor(106),

This question was asking about the adverse effects of proton pump inhibitors especially given previous kidney issues. PPIs decrease serum Mg and serum Ca absorption and can increase the risk of fracture (especially in the elderly).

yotsubato  PPI therapy *begins* the day she presents. She has not taken PPI before +8  
notadoctor  You're right, I missed that! +  
naught  MEN 1 is pituitary (monitor cortisol), pancreas, parathyroid (monitor calcium) but is not the ask of this question. +  

submitted by brolycow(20),

He has heart failure which leads to a decrease in renal blood flow and prerenal azotemia. In prerenal azotemia, BUN:Cr ratio is >= 20; Activation of the RAAS system due to the prerenal azotemia means that the spec grav is high at 1.025 and he is holding onto sodium so urinary sodium will be low (<20, FENa <1%).

figprincess  did you figure out the the ratio by actually divding out the numbers since the q didn't give it as a ratio? also what resource tells us what prerenal spec gravity should be? +  
brolycow  I just usually remember from class that spec grav 1.001-1.010 is considered dilute urine, and anything 1.025 and above is concentrated. For this question specifically, I think I remember there only being one option that even had the ratio >=20, all of the others were like 15 or less, so just have to rule them out. +3  
benzjonez  Very helpful video for acute kidney injury: https://www.youtube.com/watch?v=bMp6IxDKK2Q +2  
notadoctor  Another explanation that helped me is that inability to concentrate the urine means something is wrong with the kidneys. If you have dilute urine, or the spec gravity is between 1.001-1.010 in someone with low urine output it suggests something is wrong with the concentration mechanisms of the kidney. Because this person had congestive heart failure we were already looking for something that matched up with prerenal azotemia so we can pretty much get rid of all the answer choices that suggest other azotemias. Then finally to get the precise answer I looked at the BUN/Cr ratio which you would expect to be high(>= 20). +  
mikay92  Would fully recommend the OnlineMedEd video on AKI. Goes through the differential, lab results, treatment, etc in a very clear and concise manner. +  
drdoom  repost via @benzjonez -> https://www.youtube.com/watch?v=bMp6IxDKK2Q +  
drdoom  @mikay92 is this the OnlineMedEd video you're referring to? -> https://youtu.be/EWFgzVtMN50 +1  
drdoom  aha! there is an updated AKI video but you need an OnlineMedEd (free) account to view it: https://onlinemeded.org/spa/nephrology/acute-kidney-injury/acquire +  

submitted by mousie(127),

Can someone please explain this to me? I don't understand why starting the other drug would not count as exclusion criteria?

seagull  This has to do with Intention-to-treat analysis. Essentially, when participants are non-adherent but the data shouldn't be lost. They just undergo another statistical model to account for their changes. Here is a nice video https://www.youtube.com/watch?v=Kps3VzbykFQ&t=7s +10  
dr.xx  Where does the question mention "intention-to-treat"? +  
notadoctor  They seem to be pretty obsessed with "intention-to-treat" it's been asked in one way or another in all the new NBMEs that I've done. (Haven't done 24 as yet) +7  
wutuwantbruv  They don't, intention-to-treat is just the best way to go about it @dr.xx +  
smc213  Great for ITT: https://www.youtube.com/watch?v=Kps3VzbykFQ +2  
yex  I agree with @notadoctor !! +  
ergogenic22  i think if it were per protocol, both groups would be excluded, the ones that were inconsistent, the ones that dropped out, and the ones that switched. But answer choices only allow ITT or exclusion of one group. +  

submitted by notadoctor(106),

The definition of Decision-Making Capacity according to B+B is ability to comprehend information about illness and treatment options and make choices in keeping with personal values.

notadoctor  The decision must also remain stable over time, which is the "consistent values" part of the answer. +7  

with PCT you are supposed to avoid excessive sunlight and UV exposure. Methoxsalen makes your skin more susceptible to UV light.

notadoctor  Wouldn't UV light also be contraindicated in Vitiligo? +3  
sweetmed  Phototherapy with photochemotherapy (PUVA) is a well-known and well-studied modality for the treatment of psoriasis, which involves systemic or topical administration of chemicals known as psoralens and administration of ultraviolet light in increasing dosages after requisite time gap. PUVA is also used in the treatment of widespread vitiligo with moderately good results, though it is being surpassed by ultraviolet B (UVB), which is equally or slightly more efficacious with fewer side effects. +6  
dashou19  Honestly, I didn't even know what Methoxsalen is, just chose the right answer because I know you can not give UV light to people with PCT... +7  

submitted by sklawpirt(19),

I think the idea here is simply that one should think about where vesicles are coming from on their way to the golgi complex.

"Two steps forward and one step back." Specfically the question may be referring to a rare craniofacial disorder. an awarenesss of that disease is not necessary. What is necessary is understanding the origin from where vesicles are traficked to the Golgi apparatus.

COPI protein is needed to coat vescles from the RER to send to golgi. Thus, with a mutation in that protein, the packaged proteins that should bleb off and be sent to the golgi, instead accumulate in the RER and dilate it. Thus the answer.


hayayah  pg. 47 on FA got the good visuals! +2  
notadoctor  COPII* proteins are needed to coat vesicles from the RER to Golgi. "Two(COPII) steps forward; one(COPI) step back." Anterograde goes RER -> Golgi -> Lysosomes/Secretory Vesicles -> Plasma membrane +13  
titanesxvi  why not small lysosomes? +2  
varunmehru  and I thought large lysosomes due to lack of enzymes to degrade +  
samsam3711  The size of the lysosome is not affected by the presence or absence of protein, but its function is compromised (eg. protein is getting stuck in the RER) +  
fattyacid  I hope this helps to whomever was lost like me Null mutation: A mutation (a change) in a gene that leads to its not being transcribed into RNA and/or translated into a functional protein product. For example, a null mutation in a gene that usually encodes a specific enzyme leads to the production of a nonfunctional enzyme or no enzyme at all. +1  

submitted by mcl(378),

Patient may have hereditary angioedema, which is associated with "recurrent attacks of intense, massive, localized subcutaneous edema involving the extremities, genitalia, face, or trunk, or submucosal edema of upper airway or bowels". The article goes on to say "C1-esterase inhibitor works directly on the complement and contact plasma cascades to reduce bradykinin release" which is also probably good to know.


notadoctor  Thought this was a trick question as C1 esterase deficiency also results in a decrease in C4. However, the second answer choice was not referring to C4 but to C4 binding protein, which I now know is different. I also didn't realize C1 esterase was technically a complement protein. +4  
youssefa  Based on many sources hereditary angioedema does NOT cause a rash (urticaria) which is a main differentiating point between angioedema and allergy. This mislead me in this question. Any clarification? +11  
ergogenic22  +1 on the above because uptodate states that c1 esterase inhibitor deficiency, both acquired and nonhereditary, are both non-urticarial, non-pruritic, and that is confirmed by the above linked article +1  
sahusema  Question writer probably didn't know the difference between cutaneous urticaria and subcutaneous edema. +3  
almondbreeze  same. got it wrong bc the pt didn't have sx of hereditary angioedema - swollen lips and eyelids +1  

submitted by oznefu(9),

how do you narrow down that testosterone increased hemoglobin concentration? just a random fact to know? i put alkaline phosphatase because i figured increased testosterone will increase bone growth and ruled out prostate-specific antigen bc it’s a woman.

hysitron  I guessed this one cause men have a higher hemoglobin than women. +4  
notadoctor  High levels of testosterone will result in amenorrhea. I guessed that since she's not menstruating she will not be losing blood and therefore hemoglobin. Therefore her hemoglobin levels will be higher than expected. +4  
meningitis  It kinda makes sense knowing testosterone causes catabolism so I was in between Alkaline phosphatase and hemoglobin... +1  
enbeemee  isn't testosterone anabolic? +2