DIP Episode 587 - 2025 USMLE Step 1 Free 120 Discussion Part 5b (Q46-50, super helpful for Step 2 and 3!)

All right, welcome. This is episode 587 of the Divine Intervention Podcast. Into this podcast we're going to be continuing our series on the step one free one twenty. This is going to be series five. This is going to be part five B. So we stopped at 45 because there were a lot of things I really wanted to go through in terms of just content and the pathophase and testing in principle. So we're going to finish that up. So question 46 says, 40 year old woman comes to the physician because of our running nose sneezing and itching eyes on exposure to cats and childhood. Anti allergy drugs have not provided relief. Her symptoms improve with a program of desensitization involving a administration of increasing doses of the allergy. Which of the following is the most likely mechanism of the beneficial effect of this treatment? So this person basically is or told that okay, we're going to start a desensitization program. This is actually something that's not really common, but it's actually very effective for the people that are willing to kind of stick it through. So many people call this immunotherapy. In fact, this was probably like some of the earliest kinds of immunotherapy that existed. So basically what does allergy desensitization involve? Basically, you keep getting bigger and bigger doses of things, bigger and bigger doses of the allergy. And then over time, that induces a lot of tolerance by your immune system. A bunch of things actually happen.

For example, your immune system starts making these regulatory T cells that make things like into looking 10 and TGF beta. Pretty much kind of dumb down your immune system. You switch away from a T-hopper to a response to more of a T-hopper one response. And also in that process, you make a bunch of IgG antibodies that can pretty much bind to the IgE so that the allergen cannot interact with the IgE that we find on the surfaces of mast cells. Because remember, mast cells have IgE on their surfaces. So when the IgE is bound by allergen, you have cross linking of the IgE and then those mast cells release things like histamines and bradykinins, which can cause a very nasty allergic response. So if you have IgG antibodies that bind to those IgEs on the surfaces of mast cells, then the allergen would not be able to interact with IgE to cause that cross linking. So a bunch of different things happen. A bunch of different things happen. So let's look at the answer. As option A says, formation of dimers that stimulate clearance by macrophage phagocyteosis. That's nothing like what I just said. The only thing about dimers and the immune system is that IgA is a dimer. Right, remember, IgM is a pentober. So that's not related at all. Option B says increase production of IgG antibodies that block allergen binding to mast cells. That sounds a lot like what I said, at least on one of the mechanisms. So I'm going to go to option B here.

Option C says overwhelming IgE binding sites to resulting in activation of mast cells. No, you're not overwhelming those binding sites. No, what you're doing is you're basically trying to make those binding sites no longer available for binding by allergen because IgG has taken over those sites. So C is wrong. Option D says production of an anti-idiotypic antibody to IgE that results in its clearance. No, we're not trying to clear IgE from this circulation. No, right? And basically like making antibodies against IgE. No, you're not making anti-IGE antibodies. You're just making antibodies that bind to the binding sites that allergens would add ordinarily bind to on IgE to cause that cross-linking and trigger issues. Option D is a very good statement that is very, very, very wrong. It's a good statement that is very, very wrong. And then option E says stimulation of macrophages to produce anti-inflammatory cytokines. That's not exactly true. It's regulatory T cells that we stimulate. It's regulatory T cells that we stimulate. Right? So that they make IL-10, you know, which is a very good immunosuppressant and things of that nature. All right. So we're going to go to question number 47. We're going to go to question 47. Question 47. So question 47 says a three-week-old girl delivered a term with no complications.

A three-week-old girl delivered a term with no complications is brought to the physician by her mother because of a one-week history of yellow eyes and skin, tan colored stools and dark brown urine. The newborn has been breastfeeding without difficulty. She's alert and appears to be in no acute distress. She's at the 50th percentile for length and weight. Physical examination shows clearly to us in jundes. There's mild hepato megaly. The split is not possible. Lops studies show. So a hemoglobin is 14.4. Immodocritis 43%. Why count is fine. Serum albumin is pretty. Excuse me. Serum albumin doesn't seem too bad, but the total bilirbin is pretty high. 14 and the direct fraction is 12.5. So this tells us that this is a direct hyperbidimia and then AST and LT. Right? AST is 50. LT is 45. Okay. So the thing is whenever you see jundes in a newborn, the first decision you should make, if you want to be high-yielding, you're thinking is, is this direct or indirect hyperbidimia? That's literally the first thing you're supposed to think about. Right? And we see it's direct because literally once you know what's going on, you're going to be pretty good to go in terms of diagnosis. Right? So we know that this is direct. So we know that this is probably some kind of obstructive issue. Right? Probably some kind of obstructive issue. Right? So you know, biliria treasurer is the clear code answer here and I'm going to go through every single answer here. But biliria treasurer, right?

Your bile docs do not develop properly. Right? So you pretty much, you have issues excreting out bile. Exreting out direct bilirbin. Right? Into the bilirii tree to get it out and excreted. But that doesn't happen. Right? So you're going to have a direct hyperbidimia. A regular and a hard scene from type one. Basically is an issue with UDP gluconearsil transfer rates. Remember, UDP gluconearsil transfer is an enzyme that pretty much helps us conjugate indirebiliurbin. So if that enzyme is not working like you have a complete absence of it, you're going to have a build up of indirebiliurbin. But here we see that we have a build up of direct biliribin. So that doesn't really make sense to what's going on here. And then option C says Gilbert syndrome. Gilbert syndrome is where you have like a partial issue with UDP gluconearsil transfer it. Typically the way that thing is going to present is that you're going to have people that you know they have like some medical illness or they go through surgery or they're really stressed, you know, maybe they're studying for step one. And then they have this mild increase in indirebiliurbin because again UDPGT activities is kind of reduced. When you see that they're going to have indirect type of biliribinemia, that does not really match up with what we see in this question. And remember, Gilbert syndrome is not treated. That's very high you'll to know. Gilbert syndrome is not treated.

You're not going to have any long-term consequences because you have Gilbert syndrome. And then option D says he-molytic disease of the newborn. That's also wrong, right? Because whenever you have he-molytic disease of the newborn, let's say because they were anti-arachantibodies or anti-keleantibodies or anti-duffy antibodies, right? The thing that's going to happen is you're going to have a lot of himolises. Whenever you have a lot of himolises, what do you think is going to happen to your indirebiliurbin? It's going to go up. And then physiologic jaundice. Remember physiologic jaundice is always indirect. I'm going to say that again. Physiologic jaundice is always indirect type of biliribinemia. Whenever you see a newborn with hyperbibiliuribinemia and it's direct or it's within the first 24 hours of life, that is always pathologic. I'm going to say that again. Actually, I think I need to clarify a few things here. But how can you know that jaundice is pathologic in a child? Number one, if it happens within the first 24 hours of life, it can never be physiologic in that circumstance. That's number one. Number two, if a person has jaundice, if a newborn has jaundice and they have direct type of biliribinemia, it is automatically pathologic. A newborn should under no circumstances really have any degree of direct type of biliribinemia. So just going to keep that in mind. Physiologic jaundice is usually jaundice that arises after the first 24 hours of life.

It's usually indirect. And why does that happen? Because some people may wonder, why does this happen? Is it like newborns kind of committed any crime? No, they didn't commit any crime. Right? But there are two factors that play here, which is actually kind of cool to understand. Number one is when you're in utero, you're not really using your lungs. That's one thing many people do not realize. Your lungs are basically a bag of fluid, a bag of amniotic fluid. So what happens? Well, because you're not using your lungs in utero, that is interpreted as a state of relative hypoxia. And what happens when you have a state of relative hypoxia? Your body is like, oh, gee, I'm going to make a ton of epoch. So the fetal kidneys make a lot of very throat poetin. So because the fetal kidneys make a lot of very throat poetin, that causes polycythemia. So actually, when kids are in utero, they're actually pretty polycythemic. In fact, when they come out of the womb, just do a blood run out on a newborn. You get to notice that, ooh, man, this shows hematocrytics pretty high. That's perfectly normal. And I don't think that also causes that epoch response in utero is that think about it. What kind of hemoglobin do you have a ton of when you're in utero? You have a ton of hemoglobin F. Hemoglobin F has a very strong affinity for oxygen. So it doesn't release oxygen to tissues as well as we would want. So again, the tissues in utero have a relative level of hypoxia going on.

So that triggers epoch production. So when kids are in utero, being in utero is a state. Hopefully with the two mechanisms I've explained, being in utero is a state of relative hypoxia that is going to cause epoch production and that's going to cause polycythemia. But after the newborn comes out, the child is no longer in those hard conditions. The lungs are working. Everything is great. So all those excess red cells that we're in the utero, they have to be gotten rid of. And if you think about it in the process of breaking down all those red cells, you're going to develop a lot of, you're going to make a lot of interbularbina. So that's why indirect hyperbularbinaemia is the hallmark of physiologic jaundice. Now there's one more mechanism I play here as well with physiologic jaundice and why you know newborns may have jaundice. The thing is, as a newborn, you have about 1% of the UDP glucoronocytransferase activity compared to an adult. So think about it. You already is almost like a double one. Number one, you're making a ton of interbularbina because all those excess red cells you made while you're in utero, you're breaking them down. But number two, you also have like 1% or less than 1% of the activity of the adult enzyme that normally helps us break down. I mean, sorry, it normally helps us conjugate bilirubin. So those two things together will conspire to cause an indirect hyperbularbinaemia and cause physiologic jaundice.

So again, hopefully that giving you that context really helps you with understanding this material. But the answer here is going to be option A because this child has direct hyperbularbinaemia. All right, that's the thing with some of these step one podcasts. You really can't kind of speak through things because you need to kind of break things down, right? Okay. So because it's basic science. Okay, so question 40, it says 65 year old woman comes to the physician for a follow up examination after blood pressure measurements were 175 over 105 millimeters of mercury. And 185 over 110 millimeters of mercury one and three weeks ago respectively. She has well control type two diabetes mellitus. Her blood pressure now is 175 over 110 millimeters of mercury. Physical examination shows no other abnormalities. Anti-hypertensive therapy started, but her blood pressure remains elevated at her next visit three weeks later. Lab studies show increased plasma reading activity. The exercise sedimentation rate and the serm electrolytes are within the reference ranges. And geography shows a high grade stenosis of the proximal right renal artery. The left renal artery appears normal, which of the following is the most likely diagnosis? Well, again, this pressing clearly from this question likely has renal anaerostenosis, right? So it makes sense that the plasma reading activity is increased, right?

Because if you have renal artery stenosis, you're not profusing your afternoon arterial well at all. So since you're not profusing your afternoon arterial well, your GG cells are going to freak out, your juxtaglimarial cells. They're going to freak out and they're going to make a lot of reining, right? And then that reining is going to convert angiotensinogen to angiotensin one. And then that angiotensin one will go to the lungs and then the endothelial cells of your pulmonary capillaries will convert that angiotensin one to angiotensin two. And then that angiotensin two, one of the things you can do is that you can go to the zonal glomerulosa of the adrenal cortex and cause you to make a lot of outdoster. And outdoster and causes you to reabsorb a lot of sodium and water from your kidneys. That's going to raise your blood volume and that's also going to raise your blood pressure. Another thing that angiotensin two does is that it goes to the super optic nucleus of the hypothylamus and causes you to make a lot of EDH anti-diarrytic hormone. And what does EDH do? EDH causes you to soak up more free water from your urine. If that happens, that's also going to raise your blood volume and that's going to raise your blood pressure. So it makes sense that this person has hypertension. And also remember angiotensin two is one of the most powerful visual constructors known to mankind. So it's a very big visual constructor. So it climbs down on your vessels.

It increases your systemic vascular resistance. That's going to raise the person's blood pressure. It's not very surprising that the person's that stomach blood pressure is also pretty high. So renal artery stenosis typically is going to be a problem with atherosclerosis. And again, usually we're going to see this in people that are older. We see this person in 65 years old and has trouble. So this person has atherosclerosis. It's an atherosclerotic problem. Just like you can have atherosclerosis of your coronary vessels, of your carotids, you can also have atherosclerosis of your renal arteries because it has a lot of blood flow. So if you're very unhealthy person, I'm sorry to say, but like this person has type 2 diabetes, that can certainly cause a problem. So the answer is A. The thing is fibromuscular dysplasia also increases your plasma reading activity. Or fibromuscular dysplasia is not an issue of atherosclerosis. It's actually a muscle problem. Look at the name fibromuscular dysplasia. It's a problem with the media layer of the artery of the renal artery. Instead of renal arteries, the nurses that's one issue the intima layer. Atherosclerosis largely goes after the intima. fibromuscular dysplasia largely goes after the media. And fibromuscular dysplasia typically is going to be a much younger person. I would not peg that in a 65 year old on the exam. So option C is definitely wrong. Option B says congenital renal artery hypoplasia.

If it was congenital, I would hope that the person has been having symptoms of nasty hypertension, like well before age 65. It makes no issue that we picked up a lot earlier. Takaya so atheritis, that's a kind of vasculitis. They're going to have issues with pulses in their extremities. We don't call it postless disease for no reason. Usually it's going to be people of Asian ancestry under age 50. And in temporal atheritis, you're going to see blindness, temporal pain and all those things. It can cause hypertension, but not typically. Remember, that's a large piece of vasculitis. I'm not going to pick that. So option E is also wrong. So the answer is here is definitely going to be option A. Again, if the USM is put renal artery stenosis, everybody will get crushed the exams and get 100%. But again, the USMLE's classic thing they love to do. You've heard me say this many times on this podcast is this concept of the derivative, where they take what you know and just describe it in other terms, just to kind of mix things up. And I think it's one of the USMLE's most effective tools against people that just solely use on key and just memorize and have like no understanding or no context of what's going on. Question 49 says a 46 year old woman comes to the physician because of a one month history of fatigue, weakness and palpitations. She has advanced kidney disease as a result of continued use of combination and outgisics for low back pain.

She has high potential well-controlled with a loop diuretic, a bit of an energy blocker, and a dihydroperiodine calcium channel blocker. She has a history of gastritis and hemorrhoids associated with alcohol blood in the stools. She is in no acute distress. Her temperature is 90.2 degrees Fahrenheit. Her pulse is fine, reservisions are fine and blood pressure is 150 or 86. That's high, which makes sense if your kidneys don't work, that's usually a pretty good cause of hypertension. Physical examination shows mildly a mid-epigastric tenderness to palpation and 2 plus a dim of the lower extremities. Cardiac examination shows an S4 gallop. Test of this tool for cold blood is positive. Lab studies show. So hemoglobin is low, hemotocritis, low, mcv is normal, right? So these are normal cedric anemia. The ferritin, I don't know what a normal ferritin is, but whatever. The answers to this question kind of makes a lot of obvious sense. The folitis is fine, total iron, I don't know what a normal value is, but whatever. Transparencyration is normal. Latity, hydrogenase, again, I don't know what a normal value is, but that looks pretty normal to me. What are the folines the most likely cause of this patient's anemia? One thing I've noticed on the USML is that if something is really bad, it usually stands out pretty well, right? So you see many people dutyfully checking up every single lab. That's not a habit I have on the exam. So just kind of eyeball things, right?

Like we can clearly see that the hemoglobin is low, right? We can clearly see the mcv is normal. There are certain things you should know of the top of your head like what a normal mcv should be, right? 80 to 100, right? So this person has kidney disease and then surprise, call me surprise that the person has a low hemoglobin. Of course, this person has anemia of chronic kidney disease, right? Remember, your kidneys make ipo. If your kidneys are not working, you're in making no ipo. If you don't make ipo, you're going to get in trouble with anemia, right? Because ipo stimulates your your rib loss health precursors to make rib loss cells, right? So usually when people have anemia of chronic kidney disease, it's typically a raises because their ipo is low, right? So they're not stability in your rib loss health precursors to make a rib cells, right? So option A says boomer suppression, that's wrong, right? We're going to say that with chemotherapy or some drug that kind of suppresses the immune system. So that's wrong, right? Like a post transplant patient, that doesn't make any sense. Option B says decrease evil production. Yeah, that's the right answer. Option C says intravascula hemolysis. Well, if a person had a lot of hemolysis, the LDH will probably be pretty high, right? Remember, whenever you have a lot of cells exploding, your lactated hydrogen is goes up. Again, I'm not going to go through the trouble of scrolling down and looking for the LDH levels, right?

But this doesn't just really agree with the question. And when people have really high LDH, again, it's really going to stand out. This 62, don't really stand out very much to me, right? Remember, whenever you have a lot of hemolysis, your LDH will go up. Why? Because lactated hydrogen is an intracellular enzyme. So whenever you have a lot of hemolysis of cells or a lot of cells exploding, even in things like ruptum myoluses, orientations like inflammation, that's going to cause, because inflammation causes cells to rip apart, right? That can raise your LDH levels, right? And also remember, so I could do this is also raises LDH, but I guess so I could do this is also technically an inflammatory problem. All right. Now, option D says iron deficiency anemia. Well, that's wrong, because we know that iron deficiency anemia is a microcytic anemia and this person has a normal acidic anemia. And then spilling sequestration. No, spilling sequestration is not going to cause you to have anemia. If anything, it will cause you to have a thrombocytopenia, because your spleen can hold up to 30% of your pool of platelets. That doesn't make any sense. So question is definitely wrong. The answer to question 49 is definitely option B. All right. Now, 46 year old woman comes to the physician because of a three day history of intermittent pain with your inpatient and increase urinary frequency. She says that she had one similar episode during the past six months.

She also has had irregular mentees and last month she appeared a occurred two months ago. She has no heart fever, nausea, vomiting or blood in her urine. She is sexually active with one male partner. Physical examination shows no abnormalities. Our urinalysis shows, so you know, you see some red cells in our urine, not a ton, three to five, white cells tend to 20 per hyperfilter. So she's got a paurea. And nitrite positive, lucosidest rate of estrus positive, bacteria positive. So she's clearly got a UTI. And then it says which of the full end is the strongest predisposing risk factor for development of dyspacions condition? Well, there are many reasons why people get UTI. If you're a female, your urethra is not as robustified as that of males. It's kind of wider, much easier for bugs to get through. So that's going to cause problems. So being female, resist your risk of UT Is. If you have anatomical problems with your renal systems and collecting systems like posterior urethroviles or vesico-eritory reflux, that can certainly cause issues as well. And also, if you're a person that is sexually active, whenever you're having penetrative intercourse, that means being is kind of sliding down there, is also kind of sliding bugs into you. And we see that this one seems to be pretty sexually active. So, sexually active one-mail partner. So that's probably what's going on here. Let's look at the answers. So option A says lyomayomara urethra. Lyomayomayomara urethra.

Those are fibroids. Yeah, I don't think from this woman actually does not have fibroids. So no, I'm not going to pick that. Shambi says perimenopause. So don't get me wrong. Comperemenopause raise your risk of uti's. It can a little bit, right? Because if you think about it, it can a little bit actually. When women hit perimenopause, sometimes they can have a higher risk of uti's. But that risk is very, very, very, very, very mini-school. Very mini-school is almost like a nothing burger. In fact, let me tell you this. I would not regard perimenopause as a big risk factor for uti's. It's like a nothing burger. So I'm not going to go with that. Pregnancy. Pregnancy is certainly the easiest to presciense risk of uti. It's right? Because remember, when you're pregnant, you have this also beautiful placenta that is pumping out a ton of progesterone. Well, gee, what do we know about progesterone? Progesterone is actually a very powerful smooth muscle reluctant. Relaxant. Is there a part of your urethra that has a ton of smooth muscle? Ooh, your urethers. Yeah, your urethers. So you can cause your uti relation. That's going to cause your urethesis and that's going to raise your uti risk. In fact, when women are pregnant, the risk of uti goes up a lot. But gee, this one in this question is not pregnant at all. Right? If you notice, this question, there is no great reason why you should not get rid of options in C. It's pretty much highlighting things that women does not even have.

So if you pick those, you're kind of putting yourself in hot water there. You're the one leading yourself into temptation with the NBM Es. Don't pick those answers. Option B perimenopause is, again, it's a nothing burger. But sexual intercourse is well established, right? Even mixed mechanistic sense as the penis is sliding into the woman's vagina. Right? Or, you know, it's also sliding in in box, right? So sexual intercourse is going to be the right answer here. At least that's what makes the most sense to me. So option D is going to be the right answer. All right. And just, I guess, as a prelude of coming attractions, right? So, you know, God willing, when we go into part six of this, we'll hopefully do 51 to 60. But, you know, 51, I'm kind of eyeing that and he's talking about antifongals, right? Antifongal mechanisms of actions. They're pretty high yield. I'm not going to go over 51. But let me give you a preview of coming attractions. Antifongal mechanism of actions, mechanisms of actions. Sorry. They love to test those on the USMELES a lot, right? Like, you know, like you have kind of candins, which are pretty much shut down. One, three, BIDADIC, look on synthes. We use those to control, like, you know, invasive candidal infections. Remember, you're nice starting and your, what's that close cousin of nice starting and votators in B, right? That bind to a gospel and basically poke holes in the walls of the fungus, right?

Remember, if you inhibit one three-bit of deep-looking synthes, which is what is done by a kind of candins, you're pretty much almost like the penicillin of the antifongal world, right? You're like the penicillin of the antifongal world. Because you need one three-bit of deep-looking synthes, actually helps with making the fungus out of all, right? And then, I remember 14-hour-ready methiles is inhibited by your easels, right? 14-hour-ready methiles. Those drugs also have anti-androgenic properties because they pretty much shut down androgen synthesis. And then, don't forget, I feel like this is another reason I'm forgetting. Oh, squelting epoxidies, yeah. Squelting epoxidies is shut down by a, by turbina fin. Turbina fin, turbina fin, turbina fin. Yeah, turbina fin, you can kind of shut it down. So you pretty much shut down the synthesis of Nosterol and then let's see, the device, any other antifongal you know about. Agrizio-fulvin, yeah, agrizio-fulvin is almost like an anti-microtubule agent, right? But the big thing to know with agrizio-fulvin is that G in low spainly trading carrot in pretty well. And another thing with agrizio-fulvin is we generally try to use it as second line for most fungal infections. You know why? Because he has a ton of drug interactions, right? I don't know if you know it's about agrizio-fulvin, but it's a very potent cell from P415 Ducer. So he can reduce the half-life of many other drugs because he kind of speeds up their metabolism.

So I'm just kind of trying to give you a preview of those attractions so that you can kind of think ahead with 51, but I will officially go through just to kind of keep things uniform. I'll try to see if I'm trying to go through these in chunks of 5 or 10, right? Not either or. So, so I mean, not any number of you from that. So I'll pick up from 51 next time. So we should be able to go through that quickly since I've kind of gone through many of the answers already. So let's go ahead and stop here. But thank you for listening to me today. Again, if you like the way I teach, you're going to love my classes. Next month, first week in May, I have a 25-hour step one review. Very good for both taking step 1 or level 1. Or if you're taking step 2 or step 3, level 2 or 3, those exams now have a lot of basic sciences in them. So if you want a good refreshing on basic sciences or you have a poor basic science foundation, you, you know, didn't do so well on step 1 or you did very poorly on your shelf exams. That's a class I would recommend. And then this month in the month of April, I have a, you know, test taking strategies class, bio stats class, that's four hours long, social science class, that's five hours long. These three classes are all first step one to step three. And then I have a last minute review on a 20-hour step two step three review. That's for step two and step three specifically, and also obviously level two and three.

And then in the month of June, first two weeks of June, this class is going to be held only once this year. I have a 50-hour step two step three review. That's like a super amazing class. A very limited spot's available because again, I want to personally invest in everybody attending that class, but that class is going to be epic. And it's me that's going to teach the whole class. You're going to learn testing strategies out of the wazoo. But if I'm your don't with that class, you'll basically be like a USMLE master. You'll be like absolutely ready for pretty much anything that is thrown at you on your, on your exams. All right. And there's a lot of supplemental material also giving enough 50 hour class that again, may be fine to be helpful. Okay. So and also I also offer one I want you to learn for all the USMLE and complex exams. I help with your applications, personal statements, regulators and all those things. And then I have this podcast on Apple Google Spotify. So check those out. I also have a You Tube channel, you know, Divine Intervention, USMLE podcast and videos. That's where I post the videos that I make. And then I have another website called Divine Intervention Lifelesses.com. Divine Intervention Lifelesses.com. Basically every week I post like two to three podcasts, where from a biblical perspective, many of you know, I'm a Christian, from a biblical perspective, address a life lesson. There's actually more than 300 podcasts on there.

Many people listen to those every day. Find it to be really helpful. There's actually an Apple podcast associated with that called the Divine Intervention Life Lessons podcast. So thank you for listening to me today. I'll see you in a episode 518. Have a wonderful weekend. God bless you and bye for now. Thank you.

Increased IgG antibodies bind to IgE on mast cells, preventing allergen cross-linking and subsequent degranulation.

It indicates an obstructive process (e.g., biliary atresis), which is always pathologic.

1) Breakdown of excess red blood cells (from polycythemia/HbF in utero). 2) Low activity of UDP-glucuronosyltransferase enzyme compared to adults.

Decreased renal perfusion triggers the RAAS system, leading to increased renin $\rightarrow$ Angiotensin II (vasoconstriction) and Aldosterone/ADH release (salt/water retention).

Sexual intercourse (mechanical introduction of bacteria into the urethra).

Azole antifungals (e.g., Fluconazole).

IgG antibodies bind to IgE on mast cells, preventing allergen cross-linking and subsequent histamine release.

In utero relative hypoxia (due to placental gas exchange) stimulates EPO production by fetal kidneys.

Indirect hyperbilirubinemia, due to excess RBC breakdown and low UDPGT activity.

Decreased blood flow/perfusion to the kidney triggers juxtaglomerular cells to release massive amounts of renin (RAAS activation).

Failure of the kidneys to produce adequate erythropoietin (EPO).

Azoles (e.g., Fluconazole).

IgG antibodies bind to IgE on mast cells, preventing allergen cross-linking and subsequent histamine release.

In utero relative hypoxia (due to placental gas exchange) stimulates EPO production by fetal kidneys.

Indirect hyperbilirubinemia, due to excess RBC breakdown and low UDPGT activity.

Decreased blood flow/perfusion to the kidney triggers juxtaglomerular cells to release massive amounts of renin (RAAS activation).

Failure of the kidneys to produce adequate erythropoietin (EPO).

Azoles (e.g., Fluconazole).