Study group discussion: Leriche syndrome

What is Leriche syndrome?

Claudication. Thrombosis of iliac veins in males, especially, in heavy smokers.

It's an Aortoiliac occlusive disease, a form of peripheral artery disease involving bifurcation of  abdominal aorta.

Triad seen in males as impotence, claudication, decreased or absent femoral pulse!

It's due to Atherosclerosis. Obesity, diabetes, smoking, age are risk factors.

Patients getting treated should be checked for CNS, CVS, 1st for any thrombosis and then go for the treatment of leg.

Doppler and USG is used to diagnose it.

Yup. Also Angiography, CT or MRI.

Study group discussion: What does emulsification mean in fat digestion

What does term emulsify mean in fat digestion?

Breakage of large fat globules into small ones by bile is called emulsification of fat.

Making the fat to be smaller particles, helps it mix in with the water. Eg. Milk is an emulsion of fat and water.

Yes.. just to make it easier to be digested and absorbed.

Like fat broken down into glycerol and fatty acid? Am I right?

Not really fat into glycerol and fatty acid. More to fat droplets mixing with bile. It increases the surface area to volume ratio.

More surface area : more sites for lipase to bind and digest

Thank you, guys!

Study group discussion: Neurological emergencies and isoniazid overdose

Tell me some neurological emergencies!

Status Epilepticus, Stroke, Guillain Barre syndrome syndrome, Myasthenia gravis, Neuroleptic malignant syndrome, spinal cord compression, subarachnoid hemorrhage!

Okay!

But why Guillain-Barré syndrome?

Respiratory paralysis. That's the reason they die, I guess.

Yep. Respiratory paralysis is the cause of death.

The same reason, respiratory paralysis, for myasthenia too?

Yep.

I read about one more - Overdose of isoniazid. That can be fatal too.

Isoniazid overdose depletes vitamin B6 in the brain. And B6 is a cofactor for the enzyme that convertes glutamate to GABA.
That causes decrease in the inhibitory neurotransmitter, GABA. That's why, the acute manifestation is seizures.

Commonly seen in rural areas because patients with TB neglect doses and consume all of them together.

Didn't know about this. We'll educate our patients better in the future! Thanks!

Study group discussion: Lemierre's syndrome

What can you folks tell me about lemierre's syndrome?

Caused by fusobacterium necrophilus.. Initial presentation is like Streptococcus pharyngitis but ASLO negative.

And rapidly transforms into complication - Intravascular clots, etc.
Metronidazole and high dose penicillin used for treatment. Not very common, I think.

Interesting.

Clots in the internal jugular vein.. is fibrynolitic therapy indicated?

Dunno.

It seems that the clot dissolves itself when the infection heals, so only antibiotic therapy is indicated.

Okay!

Study group discussion: Heyde's syndrome

66 year old male, painless bright red blood per rectum started this morning. Has pansystolic murmur in right 2nd intercostal space. What is the cause of bleeding?

Right side 2nd ICS, so it's aortic stenosis. Now the patient has bleeding. How do we put together AS with bleeding?

*after putting all sorts of differentials for bleeding per rectum, we finally gave up and asked for hints!*

Okie, hint.  It's a vascular malformation.

Angiodysplasia! What's the association but?

Heyde's syndrome - Aortic valve stenosis with GI bleeding.

Elderly people have AD due to age and strain but bleeding from it associated with AS is Hyde's syndrome!

Meaning normal people have less chances compared to the ones with aortic stenosis?
That explains it.

Wow! Didn't know this. Nice, thanks people!

Study group discussion: Fontanelles and thyroid hormone

Guys, remember we were talking about craniosynotosis? I think it was Pfeiffer syndrome we were talking about. So I found out about another condition that causes craniosynotosis in the new born which is acquired and can be prevented. Anyone wants to guess?

Is it due to some drug?

No. It's a hormonal imbalance!

Due to thyroid hormone?

Hyperthyroidism!

Correct!

Yaaay.

Hyperthyroidism in pregnancy can cause craniosynotosis in the neonate!

Oh oh.. Vice versa, what happens in hypothyroidism?

Macrocephaly? Mental retardation?

Umm yes. But delayed closure of fontanelles is what I was looking for!

Oh right.

Speaking of fontanelles.. Which condition causing bulging fontanelles and which conditions cause depression of fontanelles?

Hydrocephlus - Bulging.

Bulging Fontanelles in increased intracranial tension. Depressed in dehydration.

Correct!

When does the posterior fontanelle close?

At birth. Or right before birth or right after!

When does the anterior fontanelle close?

Anterior fontanelle 15-18 months.

Correcto!

It's fun when you know the answers :D

Haha true that!

Study group discussion: Varicocele

Some questions regarding varicocele. So what is varicocele?

The increase of the testicular venous pampiniform plexus. Gives the characteristic bag of worms appearance.

Yes! So there is dilatation of this pampiniform plexus!

If it occurs suddenly on the right side. It as an indicative sign of right renal cancer.

Why is left sided varicocele  more common than right?

Left side enters at right angle!

And I am confused.. Which testicular vein drains where?

Right goes in IVC, left in renal. So that's why left is more common
Mnemonic! http://medicowesome.blogspot.ae/2014/03/left-testicular-vein-drains-into.html

What to suspect when you see right sided varicocele which are not common though?

Obstruction of IVC

Brilliant!!!

The right spermatic vein drains at more obtuse angle to IVC. So more likely some obstruction in IVC.

*a debate went on whether varicocele cause sexual dysfunction, sterility, infertility or not. The one who posts the link to the research paper, typically wins*

*Key questions raised* What is the function of this plexus? What would happens if patient is not treated? The pampiniform plexus forms a counter current system with testicular arteries. Hence. Maintaining a low temperature. They take away the heat from the arteries. So azoospermia? The sperms won't survive in the increased temperature? Does the erectile dysfunction occurs in varicocele?

*Conclusion* Varicocele (grade 3) is associated with significant reduction in testicular function with significant increase in serum levels of FSH and LH, which may cause erectile dysfunction and male infertility.
Source: http://www.ncbi.nlm.nih.gov/pubmed/11111867

Study group discussion: Ligamentum venosum and ligamentum arteriosum

Can someone explain the formation of ligamentum venosum to me? I read up on it and re-listened to the lecture but I feel like I'm confusing myself :(

The formation or why it's there?

The origin.. As in what it is a remnant of and how?

It's the remnant of the ductus venosum which shunts blood away from the developing liver to go directly into the inferior vena cava. Since the developing liver doesn't need a huge amount of blood supply.

Oh...That makes sense.

Yup. So the umbilical veins brings nutrients and oxygen from the placenta, so we need to bypass the liver via the ductus venosus. Then when we are back in the Right ventricle, we don't need much blood into the lungs so we shunt it into the main circulation via ductus arteriosus.

Which later turns into ligamentum arteriosum! :D
Now everything is in place! Thank you so much!

No problem :)

Study group discussion: Parasites that cause carcinoma of the gall bladder

Which parasites are associated with gall bladder cancer?

Chronic schistosoma is associated with bladder cancer.

Flukes!

Fasciola!

Clonorchis sinensis.
Fasciola hepatica too.

Roundworms block the the CBD.

CBD?

Common bile duct.

But that'll be associated with jaundice. Not carcinoma!

Study group discussion: Hernia

What is Richter's, Littres, pantaloon hernia?

Ritchers is the one when part of circumference of intestine is involved, right?

Yup.

How do you remember this? Any mnemonic?

You can remember richters hernia as it has C-part of Circumference of bowel.

Pantaloon is when there is indirect plus direct hernia so two sacs are there.

In Littres, I think the meckels diverticulum is a part of the sac.

Which is the commonest type of hernia in females?

Inscional hernia is commonest in females.

Aren't femoral common in females?

The most common in females in indirect inguinal. But I guess you want to ask about femoral. Femoral hernia are overall commonest in females. But they are not the most common type in females.

Because of wider pelvis.

Thanks! Got it.

Some days back I had asked about the name of hernia that includes appendix.
Finally, got its name :D
It's amyand hernia,

Study group discussion: Pfeiffer disease and Pfeiffer syndrome

What's Pfeiffer disease and Pfeiffer syndrome?

Pfeiffer disease - Glandular fever -Infectious mononucleosis - Kissing disease.

Pfeiffer syndrome is craniosynostosis with hearing loss, a genetic disorder.

Craniosynotosis?
Early fusion of premature bones.

What type of craniosynotosis? There are several types!

Sutures fused and no place for growth of brain. Accordingly you get different shapes of skull - Coronal, cloverleaf shape or a boat shaped skull.

Type 1 is classic, with no neurological impairment.
Type 2 is clover leaf shaped head and retardation of growth with neurological impairment.
There's type 3 too.

Why do you have such an extensive knowledge on this rare syndrome?

Actually, there was an infant girl with craniosynostosis.
Her mother complained that she used to regurgitate the milk after each feed. (This was probably because of the raised ICT.)
The doctor's had to operate - Break the fused bones to provide space for the brain to grow.

Breaking up bones for the brain to grow, now that's something awesome!

Wow.

She's safe now (:

Study group discussiont: Acute lymphangitis

This patient presented with rapidly progressive left arm pain and erythema. Physical examination revealed a small blister on his left third finger, which had been injured during a lacrosse game, with surrounding warmth, tenderness, erythema, and linear streaking to the elbow. diagnosis?

*a picture of acute lymphangitis was posted in the group, I can not upload it here because of copyright purposes*

Is it a lymphangitis?

Yes! acute lymphangitis!

Nice! Any further details regarding lymphangitis?

About lymphangitis.. It's inflammation of the lymphatics.

The most common cause of lymphangitis is streptococcal infection. The shape of the lesion is very caracteristic since it follows the lymphatic vessel path.

Thanks for the further information!

Or a sporothrix infection. Though the history doesn't suggest anything like it.

What history should the guy have to suggest a sporothrix infection?

The fungus can enter the skin through small cuts or punctures from thorns, barbs, pine needles, or wires. In rare cases, inhalation of the fungus can cause pulmonary infection.

Correct! Rose gardeners especially.

Thank you, IkaN, you are the best!

Haha. It's okay.

Study group discussion: Uncouplers of oxidative phosphorylation

In electron transport chain, cyanide inhibits the last step.

Even dicoumarol is an uncoupler.

There was another drug used for weight loss that's an uncoupler.. Which one was that?

Dinitrophenol?

Yes!

Review question: What do new borns have that is an uncoupler? Why is it important?

UCP 1

Brown fat

I had to Google UCP 1. The answer I was expecting was simple brown fat :P
For those who don't know, UCP 1 or thermogenin is uncoupling protein 1 present in brown fat.

UCP-1 (Thermogenin) - Non shivering thermogenesis in brown fat in

I think, these UCP play great role when polar bear comes out from hibernation and also in human infant.

Yes, the polar bear!

Speaking of bears - What will happen to you if you eat a polar bear's liver?

Vitamin A toxicity?

Yes! Vitamin A toxicity! Mostly, increased intracranial pressure.

Why given term thermogenin?

Generate heat. Uncouplers dont generate ATP.

Ya, ATP formation replace by heat releasing process.

Aspirin high dose also acts as an uncoupler. Hence, we get hyperthermia in it.

This is interesting because aspirin is used as an antipyretic and it's overdose, paradoxically, causes fever.

Yup.

What is an uncoupler?

Uncoupling protein also called ucp, cause leakage of proton from mitochondrial membrane.
This allows the proton to reenter the mitochondrial matrix without capturing ATP.
Uncoupler = Uncouples oxidation (ETC) from phosphorylation ie oxidation without phosphorylation.
So energy indtead of being trapped in ATP is displaced as HEAT (NON SHIVERING THERMOGENESIS)

Physiological uncouplers:
# UCP 1 thermogenin
# excess thyroxine
# unconjugated hyperbilirubinemia

Synthetic uncouplers:
# dicumorol (vit K analogues)
# asprin
# calcium
# valinomycin

Thanks!

Awesome!

A nice summary!