Study group discussion: Non contraceptive uses of condom

Non contraceptive uses of condom? I was asked this question in today's viva!

To prevent STIs.

Reduces incidence of HPV infection. 

Reduces chances of cervical cancer.

Condom pack to stop bleeding.

Condom to stop PPH.

Condoms can also be used as gloves for per vaginal examination where there is unavailability of gloves mostly in rural
areas. Strange but interesting fact!

Condoms are also used to cover the USG probe in transvaginal scan.

And there exists a thing called condom catheter.. Used for weaning people off from a regular foleys! Due to prolong use of foleys patient loses urge to micturate. Sometimes.. So we use condom catheter. Which is basically a condom plus a urinary catheter attatched to it.

For vaginoplasty used to make moulds.

In treatment of infertility, used for 2-3 months.

Study group discussion: Hyperuricemia

Why does pyrazinamide cause hyperuricemia?

I guess it competes with uric acid for excretion because it is a weak acid.

Ohh.. Didn't know this.

There's an interesting concept I heard learnt while studying the uric acid thingy - Why does alcohol ingestion have attacks of gout? Anyone wants to guess?

Consumption of alcohol produces gout because when alcohol is coverted to acetaldehyde, NAD is converted to NADH. More NADH causes conversion of pyruvic acid to lactic acid. Lactate is not metabolised and excreted to kidney... Increased lactic acid excreation causes decreased uric acid excretion and hence gout occurs.

Alcohol produces lactic acid which competes with uric acid.
Loop and thiazide diuretics also cause hyperuricemia through this mechanism.

Correct! We have a brilliant mind in the group! B)

A random review question from top of my head since its the topic of uric acid: Which ARB drug is a uricosuric?

Angiotensin receptor blocker, right?

Losartan.

Yup.

Low dose aspirin also competes with uric acid. High dose aspirin uricosuric by inhibiting absorption.

Wow..nice info!

Any condition causing inorganic phosphate depletion also causes hyperuricemia.

Why does phosphate depletion cause hyperuricemia though?

Hypophosphatemia leads to accumulation of AMP which is then converted into uric acid. Galactosemia fructose intolerance cause hyperurecemia through this mechanism.

Amazing concept!

I feel so jealous if you.. Biochemistry is like my biggest threat!

Updated later:
Recently, we had a discussion on hyperuricemia caused by diuretics. It was mentioned it is due to the resultant acidosis that causes hyperuricemia. I read something on those lines. Diuretics do cause acidosis cause of slight CA ase inhibitory action on the PT. Thus acidosis even caused is not very marked. They cause hyperuricemia primarily by competiting with uric acid to get secreted via the organic anion transporter in the PT. Plus as the E.C.F volume is depleted due to diuretics, there is also increased absorption of the secreted uric acid. That's what I read.

Study group discussion: 45 centimetres in length and tubes

What are structures in our body about 45 cms in length?

That's an odd question. As in why do we need to know / significance?

Just to remember! Examiner here asked us in viva.

The spinal cord, Umbilical cord, Femur, Thoracic duct.

I know the esophagus is 25 cm in length. And the length from the incisor is longer. Were you given a nasogastric tube in your viva?

No.

Nasogastric tube 104 cm I guess..?

Varies 105 cms or 75 cms Ryle's.

This is gonna sound really basic but umm.. Can anyone explain the difference between an infant feeding tube, nasogastric tube and a Ryles tube?

Ryles tube is nothing but nasogastric tube.. Used for both diagnostic and therapeutic purposes.

Ohh.. I thought nasogastric and Ryle's are different.

In infant feeding tube there are no lead shots like in Ryle's tube.. And it's 52 cm in length.

Infant tube is narrow.

Infant feeding tube is used in: Tracheoesophageal fistula
Choanal atresia
Imperforate anus
Poisoning
Upper GI bleed

Thanks!

Study group discussion: Cool fact about optic nerve

I just came to know that the optic nerve is not a true nerve! It's just the extension of diencephalon..

That's the reason, in devic's disease (neuromyelitis optica) the optic nerves are involved since they are a part of central nervous system!

Wow o.O

That's why, Optic nerve is involved in multiple sclerosis too! It's the only myelinated nerve, part of the cns!

Yup. Also since it contains the same cover of meninges.. In cases of raised ICT, you see papilloedema.

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!