Study group discussion: Clomiphene citrate

Please can you explain me the mechanism of Clomiphene citrate?
Clomiphene citrate is a Selective Estrogen Receptor Modulator!

Clomiphene citrate's primary action is to block the oestrogen receptors on the pituitary.

Hence, because of the lack of negative feedback..more of FSH is produced.. Hence more follicles.

This primarily used in ovulation induction in woman.. Main example polycystic ovarian syndrome.

Also, in males it is used if the cause of impotency is less gonaodotrophins.

Important viva question is.. Dose in females is 50mg OD but in males its 25 mg.

Ooh. Why is the dose lesser in males?

Oh that.. I never searched for it. But best guess would be in males the breakdown would be slower. Hence less drug.

Also, remember after the follicles are well stimulated injection hcg is given (cause it mimics LH) and brings out ovulation.

Extra: Side effect of clomiphene citrate is ovarian hyperstimulation syndrome in females

But never ever give hcg to a woman with PCOD.. It's contraindicated cause already LH is high. Else you will cause ovarian hyperstimulation syndrome.

Oh it's HCG, I thought it's clomiphene which was the culprit.

From what I read clomiphene does cause OHS by its own... But the gonadotrophins given externally are the major culprits.

One fact HCG is obtained from urine of pregnant woman. Even FSH and LH..urine of menopausal woman. I guess better recombinant counterparts are available though.

The conversation lead to urine and fecal transplants, will be published in the next post!

Study group discussion: Marfans syndrome

Today I learned that if someone has Marfans disease and they complain of a "tearing" feeling in their chest, they are probably having an aortic dissection and need surgery quick. Our patient made it to the hospital alive, but apparently it's commonly fatal.

Aortic dissection presents with pain radiating to the back. The radiation of pain hint is given in many multiple choice questions.

Marfan syndrome patient tend to have weak or bad joint... But how could they hyperextend their finger?

Because they have a defect in fibrillin synthesis. Synthesis of any structure with fibrillin is affected.

Good to know! I'll keep that in mind.

Fibrillin will form elastic connective tissue right?

Ohhh cool! Didn't know the association!

Fibrillin is a component of lots of types of connective tissue, I guess.

Yep

Mini mnemonic on Marfan: Marfan - Fibrillin - Marfibrillin (Merging words to remember!)

Marfan is associated wth ectopic lentis, right?

Yes, Marfans is associated with ectopia lentis. Another condition associated with ectopia lentis is homocystinuria.

What's ectopia lentis?

Displacement of the eye's lens.

Paracellular leak in the thick ascending limb

This fact had boggled me since first year physiology, finally got it figured out

Paracellular leak- sodium, potassium and chloride are absorbed into the cell by Na-2Cl-K transporter. But potassium is more permeable, hence it diffuses back into the luminal fluid. This creates positivity in the luminal fluid, which repels positive ions. Hence Mg, Ca, Na are pushed by the paracellular pathway to be absorbed.  

-M-

Study group discussion: Epigenetics

Epigenetic science is a whole new perspective. To bioethics and to humanity.

Yeah there will be some secondary factors that control this epigenetic modulation.

Decitabine and aza cytidine also work by epigenetic modulation.

I didn't get the cytidine epigenetic modulation bit. Can you please elaborate?

Epigenetics is a process where one gene is active at one time and other gene is inactive same time and vice versa.

This is due to some secondary factors.

Drugs like Decitabine and aza cytidine used in MDS has minor mechanism in epigenetics.

That's all I know ;)

Amazing.

Also epigenetics means
he interaction between the nature and nurture. Genetics and environment.

It means that if you're having a gene for diabetes doesn't make you diabetic, until there's a reaction with your environment.

Study group discussion: Deep vein thrombosis

One common fact I read a few days back was after a long journey by plane, our shoes feel tighter. It's cause of venous pooling due to lack of use of calf muscles. Hence, we have slight oedema.

This is important in case of people prone to deep vein thrombosis. So they are at a high risk of life threatening pulmonary embolism.

I use the loo so many times in planes to prevent that :P

Me too.. Shuffled from seat to seat without bothering to put those shoes on.

One documentation of case was for a man who flew for 14 hrs and got pulmonary embolus!

Study group discussion: Fetal hemoglobin

What is the difference between fetal Hb (HbF) and adult Hb (HbA)? In term of the structures?

HbA has two beta chains and HbF has two gamma chains.

The gamma fraction allows fetal Hb to have higher affinity of it for oxygen which allows it to extract oxygen from maternal blood.

And inducing Hb F production is also used in the treatment of sickle cell anemia.

Hydroxyurea is the drug used for the same.

Hb F production starts from 8th week of intra uterine life.

Fetal Hb has more affinity towards oxygen than adult Hb, meaning the oxygen dissociation curve is shifted left compared to normal adult Hb.

Left doesn't leave the oxygen! (http://medicowesome.blogspot.ae/2013/05/oxygen-hemoglobin-dissociation-curve.html)

The primary structural differences between HbF and HbA are located in or near the 2,3-BPG binding site between the γ1-γ2 interface of HbF and the β1-β2 interface of HbA. The net effect of these structural differences is that 2,3-BPG binds less tightly to deoxyHbF by comparison to deoxyHbA. Thus, 2,3-BPG does not stabilize the deoxyHbF as effectively as it stabilizes deoxyHbA, thus accounting for the leftward shift of the O2 saturation curve of HbF compared to HbA when tested with the same concentration of 2,3-BPG.

Fetal hb has more affinity because of poor binding of 2,3-DPG by the gamma polypeptide chain so it can take larger volume of oxygen than adult hb at low oxygen pressure

A higher affinity for oxygen allows higher concentrations of oxygen into fetal circulation, however this also inhibits oxygen dissociation into fetal tissue where the oxygen is needed. To overcome this, other mechanisms are in place to ensure oxygen delivery to fetal tissue: Increased Crit – higher number of red blood cells per blood volume. This is a common reaction to reduced oxygen availability. Exacerbated Bohr effect – acidic pH has a greater effect on oxygen unloading in fetal tissues allowing better oxygen delivery. Acidic pH shifts the fetal oxygen-haemoglobin dissociation curve to the right, so that oxygen unloading can occur at higher oxygen partial pressures.

Adult haemoglobin starts to be produced in utero, at around the 13th week of gestation.

I think it's 30the week the switch over from fetal Hb to adult Hb.

Its by 6th month of life.. That's when majority of a child's RBC shifts to adult haemoglobin. It's important in case of thalasaemia.. Because that's when most symptoms start showing.

What I meant to say was - Initiation of production of HbA starts from 13th week gestation.

At first, there is gradual increase in concentration of HbA until it reaches 20-30% of total Hb.

And the switch is not completed until 6 months of age.

What my hemaologist taught was HbA production will be started from 30th week of gestation and by 6th month of life only HbA is produced.

And the main function of HbF is delivering oxygen in hypoxic condition like immediately after birth.

But don't we need HbF to take oxygen from the maternal blood in the first place?

Because the partial pressures in the placenta aren't enough to allow the transfer from what I've studied.
Everything takes part in delivering oxygen depending upon tissue tension of O2. Before 7th week, there are embryonic Hb like portland, gower, etc.

Embryonic erythropiesis takes place from yolk sac.

From 7th week to 30th week liver.

After 30th week, long bones start erythropoesis.

Gene for both HbA and HbF are present since birth but Its all epigenetics that make these genes to produce one kind in one period and other type in other period.

Oh I didn't know the Hb concept in such depth.

My sir told these details. Epigenetics is given in Robbins 5th chapter.

That's all!
Be sure to let us know if there are any errors or corrections.
-IkaN

Study group experience #1

It was SO very exciting to meet new people from all over the world. I got to speak to my followers directly which I don't get to do very often with the one sided blogging.

We had people from different countries and I was internal fan girl screaming throughout the process. (Still am!)

As promised to not leave you out, this is what we discussed in the group:

Fetal hemoglobin
Epigenetics
Deep vein thrombosis

We were talking about how everyone is from different age groups and grades, some younger than others. One of the group members said, "No one is small in the face of a big dream." I found it to be very motivational. Elegantly put!

We had one negative experience, a member was sending dating messages to a girl and she left the group :(
To future group joiners, make sure you report if such a thing happens to you so that we can ban the user.

The first group is full. The plan is to not add more than 50 people in one group. (It'll prevent too many anonymous users and it won't be too annoying!) The 50 spots which are empty can be used up by friends of trusted group members on request.

The new comers will be added in the second group and everyone will get a spot. Maybe in the future we'll segregate people on time zones but for now you'll be randomly allocated.

Thank you for the wonderful experience, awesome medicos!

Looking forward to more <3

-IkaN

Medicowesome study group on Whatsapp

Some of my friends discuss questions and concepts on Whatsapp. So for a long time, I've been wanting to do this. Make a huge all time accessible study group where we can learn!

This is the first trial attempt, of course. It may not work. It might work brilliantly.

If it doesn't work out, we dissolve the group and pretend it never happened T_T

If it does, we'll be learning something new on a daily basis *_*

So who's in?

All you've got to do is message me your number. You can email me at medicowesome@gmail.com with "Whatsapp study group" in the subject.

IMPORTANT: Make sure you include your proper country code when you email me your number. (Otherwise your number won't be displayed in my Whatsapp list and I might miss you out!) 

DO NOT ignorantly leave your contact details publicly in the comments for everyone to see! *whispers* Keep it secret, keep it safe.

I'll message you in a week max.

I have a lot in mind but it varies with the response. Let's try this out first and see how it goes!

PS: I'll also try posting what we discuss on the group out here as well for those who don't have access / are uncomfortable with Whatsapp.

*hoping for the best*

-IkaN

Apoptosis: Proapoptotic and anti-apoptotic molecules mnemonic

Hello! We are going to have life and death talks today.

Just kidding. We'll be talking about apoptosis - remembering molecules that promote or inhibit apoptosis, as the title suggests.

Let's start!

"Bax kills cells with an axe."
BAX promotes apoptosis.

"Caspase converts cells into casper (the ghost)."
Caspases promotes apoptosis. (Conversion into ghosts, that is, death).

"Dying is bad."
BAD promotes apoptosis.

Getting baked is like dying.
BAK promotes apoptosis.

I think bcl 2 is saying, "be clever, live" reminding us to live longer.
bcl 2 inhibits apoptosis and thus, is anti-apoptotic.

That's all!
Life and death.
-IkaN

Oral hypoglycemic drugs and weight - Weight gain or weight loss mnemonic

Sulfonylureas, Insulin and Thiazolidinediones cause weight gain.
"SIT" is my memory aid for remembering this. (Sitting at home makes you fat.)

Biguanides like Metformin cause weight loss.
"Metformin forms you in,
makes you thin."
(I could be a poet! :P )

For Glucagon-like peptide-1 (GLP-1) receptor agonists, you need to remember that the drugs end with "-tide". Exenatide liraglutide, etc. Tide is an anagram for "diet" - so tides cause increased satiety and reduce diet :D

SGLT-2 and Weight loss: SGLT2 Surely Generates Less Tummy.

That's all!
-IkaN

Prolactin mnemonic

Hello.

Prolactin is pro-lactation hormone. It aids in breast development during pregnancy and milk secretion from the breast during nursing.

It's regulation is kind of complex which is why we'll be learning about it today. I'll also be sharing a few mnemonics that will help you remember these facts!

I have no idea about USMLE Step 1

I have noticed that some of my readers haven't spoken to anyone about USMLE step 1 exam and ask very basic questions about the preparation so I decided to write a separate post on it.

For those who have started preparing for the exam and have a general idea
- You'll find most of this post useless and redundant.
- I have marked asterisks (*) for important points you might wanna look at :)

Lastly, most of these are replies from conversations that I've had with real people so
- I haven't sequenced them in order.
- Ignore grammatical errors that I may have overlooked.
- Some of them have shout outs to Indian medical students (Simply because I know the Indian system better and it's hard to separate those points and write em again. Please don't mind that. I love you all equally, medics of the world!)

Okay, let's begin!

I just started. Which books do I get?
Kaplan notes and Goljan pathology.
* Don't buy First Aid initially since you'll be requiring a new edition in the last 3-6 months of your prep.

How do I start preparing?
You'll have to start with Kaplan videos. Supplement them with notes. Add extra points, stuff not mentioned in the videos to it. Hear Goljan audio while travelling, cleaning the house. Read the book and know it cold.

What is Goljan audio?
Recorded lectures of an absolutely amazing pathology professor, Edward Goljan.

What all is encompassed in Step one? Which subjects?
Anatomy, Biochemistry, Physiology, Pathology, Microbiology, Pharmacology and Behavioural science.

* It has a lot of clinical questions as well so it's hard for me to restrict the syllabus to basic sciences. For a hypothetical example, say, a question on burns was asked on my Step. In India, it is taught in Forensic Medicine and Toxicology and Surgery. So you get the idea? You require an over all comprehensive knowledge for Step 1.

Behavioural science?
It's Biostatistics from Preventive and Social Medicine (3rd year minor for Indian medical students) and Psychiatry from Medicine (3rd year major for Indian medical students).

If there are minor and major subjects, won't I score better if I give the exam after I am done with MBBS?
Yes, I think people who give the exam after they complete final year score better than those who give it in their basic science years simply because people from first year and second year lack clinical knowledge essential for Step 1.

I must say, my opinion is biased on my experience. I know of a senior who gave his exam before final year and scored a 265 on his Step 1 (So that's pretty awesome and you should go ahead, give the exam without doubt in your basic science years!)

Umm so why give Step 1  early?
- You're utilizing your time efficiently.
- You'll need the score to apply for electives in certain colleges.
- You get "done" with the exam and you can chill out.

When and how to register?
You'll need an ECFMG id to give the exam. That requires college stamp. You'll get the instructions online. If you can't figure it out, email me.

When do need to get the id? ASAP?
3-6 months before you feel like giving the exam, you make the id. It takes approx 1 month to make.
The thing with ECFMG id is that you need to pay a certain amount of money to make the id. That's why, I recommend you to make it when you're absolutely sure about giving the exam.

What is uWorld?
It's an online question bank. They are questions which are similar to those on Step 1 and essential to get an idea of what the exam is like.

When do I start with uWorld?
It is a resource you would like to use in the later months of your preparation because it is difficult (You can't do it without having any knowledge) and because it trains you for the real exam.

Are there other questions banks that I can do?
Many. Kaplan Q bank, USMLE Rx to name a few.
* Unlike uWorld, you can start with other question banks well before the exam because they are not very similar to the real exam, they scare the shit out of you with facts you don't know and motivate you to study.

What is NBME?
Mock exams created by examiners who write questions for the test. They predict your score.

I've heard you need to do research stuff in the field you are interested, is that right?
Yes. Research and electives are required for residency.

How do I become a part of some research?
That is later. In USA. Give your step exams first.
For Indian medical students - You can do research in India as well but it has no value. You'll get experience but that's about it. No credibility.
Procedure in very short: You'll need to contact the HOD of that department, get permission from ethics committee and contact a professor who would like to mentor you for research.

No advantage of research in Step 1?
Nope. They help you in residency match. Just get a good score for now and worry about the other details later.

(I'll keep updating the post with recent questions as and when I can.)

Related posts:

Preparing for the USMLE Step 1 exam

http://medicowesome.blogspot.ae/2015/01/preparing-for-usmle-step-1-exam.html

USMLE for Indian medical students 

http://medicowesome.blogspot.ae/2015/01/for-indian-medical-students.html

Giving the test you failed in while studying for the next exam

I'm a third year med student and today I just got my result for the annual exam and I flunked in biochem :'(
It's been like the end of the world to me today. I feel so hopeless and helpless.
I really have no idea how I'm gonna retake the exam while having the 3rd year classes side by side... I really really hope that I can do as what you did and be just awesome as you are in the future but right now I don't have a clue. Any suggestion about how to manage things side by side? - Asked on Tumblr

I'm sorry you have to go through this :(

It's not the end of the world even though you feel like it is. There is so much ahead of you.

Although I have never been through it, I had a friend who had failed and had to give the exam again in the next year.

This is what we did -

Regret and forget:
You can take a few days off to cry, feel bad about it. Regret, hate, feel guilty and blame whoever you want to. But be done with it. Once your few days of sadness are over, you have no right to complain, feel hopeless EVER. You're not allowed to feel like this again. It's very similar to what they show in movies - write on a piece of paper and burn it.

This is important because you can't feel bad for yourself while you're preparing, you can't have low energy or blame others in that phase. It's going to be very hard and you have to be strong.

Get your spirits up: Believe that you can do this. Half the battle will be in your head - the previous failure will haunt you and the anxiety will try to take over. Make sure your winning the battle in your head. YOU CAN DO IT.

Plan: Now, you have new syllabus to study and give the re-exam, right? How many months for the re-exam? How much time do you have to study for the new exam?

Tips: You wanna study the very important and parts you were weak again very throughly.

You can do it side by side, you'll need to discipline yourself to study one particular amount of time for the re-exam and one slot for the new syllabus. You can give less time for the new stuff and then study over time for it later. Passing this subject is your priority.

I love this part, telling the success story - My friend did it. She passed the exam the second time and did good in the next year subjects as well. If she can do it, you can do it too!

You will do great and you'll be much more awesome than me in the future. I believe it! :D
(The fact that you spoke about it and aren't giving up is evidence of the same.)

Just work really hard and keep fighting your way through it. All the very best!  Drop by and update us on your progress sometime later :)