A few medical conditions have presentations that are more or less the same to a layman but in reality, are polar opposites of each other. There are though, a few subtle clues which help in differentiating these conditions. Some of them are as follows-
1. The Somogyi effect and the dawn phenomenon.
These are the conditions which occur in diabetic patients which are undergoing treatment.
In the Somogyi effect, there is a rebound hyperglycemia (in the mornings) following hypoglycemia(during the night) due to the release of counter regulatory hormones.
On the other hand,the dawn phenomenon is characterized by morning hyperglycemia due to inadequate insulin dosage. It may be a possibility that the raised blood sugar is due to nocturnal GH release or increased insulin clearance in the mornings.
So, what does the patient think? That the treatment is not working, is inadequate, but the reality may be starkly different.
To pinpoint, the patient may be asked whether he feels excessive hunger during the night, experiences persistent nightmares or any other symptom during night pertaining to hypoglycemia.
3am and morning blood samples reveal hypo and hyperglycemia in the case of Somogyi effect, while hyperglycemia both the times with dawn phenomenon.
Hence, the modification in Somogyi effect is actually to decrease the insulin dose and increasing it if the patient has dawn phenomenon.
2. Anorexia and Bulimia nervosa.
Both these conditions are characterised by the patient having weight concerns and multiple episodes of self induced vomiting ,laxative abuse or extreme exercise and fasting.One might get confused as to what exactly is the underlying condition.
The primary difference between the two according to me is the patient's attitude and the quantity of food consumed.
Anorexics are primarily worried about their weight(they tend to be ballet dancers or actresses) and hence consume very less amount of food to begin with and vomit out or use laxatives to get rid of whatever is consumed. The patient tends to be almost emaciated, they have a distortion of the bodily image and beliefs that they are still overweight.
Bulimia patients too, engage in similar kinds of behaviours to lose calories but these are more driven out of guilt rather than extreme weight concerns,they usually have a normal weight.The patients have a sense of achievement that they can eat whatever they want and in any quantity until they are losing calories through vomiting, excessive exercise or laxative abuse. Contrary to anorexia, patients have episodes of binge eating then compensatory behaviours followed by hunger and then again binge eating.
Tuesday, March 3, 2015
Deceptive appearances.
Monday, March 2, 2015
Study group discussion: Difference between antibody and anti-toxin
What is the difference between an antibody and an antitoxin? Wikipedia says that antitoxin is also an antibody. But what's the difference between the two?
And if we take a vaccine, what is formed-an antibody or an antitoxin?
My understanding is a toxin cam be an antigen. An antigen is not necessarily a toxin. So an antitoxin can be an antibody, but not all antibodies are antitoxins.
Anti-toxin is something that neutralizes the toxins released by bacteria. Ex: Tetanospasmin released by Cl. tetani.
These conditions are life threatening acutely.. So you give pre-formed anti-toxin from horse serum or from multiple plasma donors.
Anti-toxin are antibodies. But you need to remember it is especially for neutralizing toxins released by bacteria.
Whereas, antibody is a very vast term. They can be formed against the cellwall of bacteria as well as one's own antigens (autoimmunity).
Multiple plasma donour means from many organisms?
When people donate blood, the antibodies from several of these people's blood is collected and given
Good explanation, Sakkan!
Study group discussion: Aspirin
Which is the classical triad of aspirin poisoning?
Idk the triad though... I just know some symptoms.
What are the symptoms?
Dehydration
Petechiae
Fever
The triad is hyperpyrexia, confusion and later death.
Death? :O
A very rare case.
Death is due to Respiratory collapse.
Fever? A drug used for pyrexia causes fever :D
Haha ironic, yes.
Pyrexia because of uncoupling of oxidative phosphorylation.
Yep. The energy in ATP gets disseminated in the form heat.
What is the treatment of aspirin overdose?
No specific antidote.
Symptomatic.. Cooling.
Vit k - For petechiae.
Increasing urine pH.
Right on! Aspirin is a weak acid.. Hence you increase its ionization to reduce absorption.. By giving sodium bicarbonate!
Yes!! Alkaline diuresis it's called!
Aspirin you just manage patient. Give iv fluid, increase urine pH, dialysis.
Dose of aspirin for prevention of MI?
Dose of aspirin in ongoing MI?
For prevention it is 81-160
For ongoing.. It is 160-325
Moving on
Why salicylates are contraindicated in children?
Reyes syndrome. They result in increase in liver transaminases plus encephalopathy.
Especially, when used for kids with viral fever.
Study group discussion: Cycloserine
I just came to know that One of the important side effects Cycloserine is suicidal tendencies!
And Cycloserine is used in MDR TB.
Exactly.
Does it have any other uses? Apart from TB?
Mental retardation... I searched online.
Hmm.
The person with MDR TB...Dies of suicide more often.
Now we know why!
No other infections?
Certain UTIs. It's antimicrobial action is due to inhibition of bacterial cell wall.
I see.
Study group discussion: Lymph nodes in various diseases
Characteristic lymph nodes in diseases:
Matted- Tuberculosis, LGV
Rubbery- Hodgkin's lymphoma.
Shotty- Syphilis.
Hard, fixed - Malignancy.
Do you know any more? Let us know in the comments section below!
Study group discussion: Biceps femoris reflex
Does anyone know what biceps femoris reflex is?
Biceps femoris reflex is a highly sensitive and reliable clinical tool for evaluation of the S1 spinal reflex pathway in radiculopathy.
It's the contraction of biceps femoris muscle when it is tapped on the lower part of its head just above its attachment on the head of fibula, with the limb slightly flexed at hip and knee.
Hope this helps :)
Thanks!
Study group discussion: ACE in lung diseases
Can anyone please explain why Serum ACE is elevated in Sarcoidosis?
ACE activity is increased in sarcoidosis, a systemic granulomatous disease that commonly affects the lungs. In sarcoidosis, ACE is thought to be produced by epithelioid cells and macrophages of the granuloma.
Serum ACE also appears to reflect the activity of the disease so we can estimate the severity or response to treatment..
You mean : Higher the ACE level , more the disease severity?
Yes.. Higher the level more the severity.
Got it . Thank yoh!
Both TB and sarcoidosis has increased levels of Adenosine Deaminase but Sarcoidosis can be distinguished from tuberculosis by serum ACE levels (In tuberculosis, decreased levels of serum ACE.)
Woah.
Study group discussion: Drug for neurological manifestations of Wilson's disease
Review question-
Which drug is used for neurological manifestations of Wilson's disease?
Penicillamine (cuprimine and depen) and trientine (syprine and trientine dihydrochloride).
Both of these drugs act by chelation of binding of copper, causing it's increased urinary excretion.
Yes, but any specific drug for neurological involvement?
It's Ammonium tetrathiomolybdate.
Glycogen storage diseases mnemonic
Hey everyone! Long time no see!
I was requested mnemonics for glycogen storage diseases recently so I thought I'd write about it -
Glycogen storage diseases from 1-6 are:
von Gierke's disease
Pompe's disease.
Cori's disease
Anderson’s disease
McArdles disease
Hers disease
The memory aid for remembering this one is actually a dirty mnemonic, I found it on tumblr (Can't remember where I read it!)
Anyway the mnemonic is -
Viagra
Pills
Cause
A
Massive
Hardon
Also, heart pumps (Pomps) blood. So that's how you can remember that the heart is affected in Pompe's disease!
And for the enzymes -
Glycogen storage disease type 1 mnemonic:
Geirke - Glucose 6 phosphatase. Both have a G!
Glycogen storage disease type 2 mnemonic:
The Pompe's disease mnemonic is a drag but for whoever this helps.. Do you guys know about the volcanic eruption in Pompeii?
The fires of Pompeii makes me think of acid (burns-fire-acid?) and how it killed children.
So acid alpha-glucosidase and affects children!
Glycogen storage disease type 3 and 4 mnemonic:
Mnemonic for Anderson’s and Cori’s is, "ABCD"
A-B(ranching)
Anderson’s - Branching enzyme.
C-D(ebranching)
Cori’s - Debranching enzyme.
Glycogen storage disease type 5 mnemonic:
Muscle phosphorylase for McArdles. Both have a M in the name!
Glycogen storage disease type 6 mnemonic:
LivHER. So Liver phosphorylase is affected in Hers disease.
That's all!
Hope you're having a wonderful time and see you in the next post xo
-IkaN
Study group discussion: Thyroid surgery practicals viva questions
Can anyone please elaborate why hyperthyroidism causes oligomenorrhea and hypothyroidism causes menorrhagia?
Hypothyroidism increases TRH.
TRH increases prolactin.
Prolactin decreases GnRH.
GnRH decreases LH and FSH.
What are the complications of multinodular goitre?
Complications of MNG - Due to obstruction - Dyspnea, dysphagia.
Malignant change, calcification are also complications.
Thanks :)
Study group discussion: Pressure and volume reservoir in the human body
Why arteries are labelled as pressure resevoir?
All artery..especially, arterioles are the main site of pressure regulation.
Veins on the other hand are called capacitance. They store at a time 60% of the total blood volume.
Therefore arterioles regulate the pressure. On the other, hand..Veins monitor the volume of blood reaching the heart
I think that is true.
And vein also called main blood resevoir.
I found out a good explanation on - Why arteries are known as pressure reservoirs?
Arteries also contain an elastic layer in their walls. Elastin is a protein fiber that has elastic qualities. During systole, large arteries distend with blood as their elastic walls stretch. During diastole, the walls rebound, thus pushing blood along. In this way the arteries act as a pressure reservoir that maintains a constant flow of blood through the capillaries despite pressure fluctuation during the cardiac cycle.
Veins on the other hand, are known as blood reservoirs.
Veins are larger and more compliant (stretchable) than arteries, thus they can hold more blood. In fact, the veins act somewhat like a blood reservoir, containing 60% of the total blood volume at rest.
Study group discussion: Morphine and atropine
* Our discussion started with this: Acute LVF management
LMNOP:
Lasex (frusemide)
Morphine (diamorphine)
Nitrates
Oxygen (sit patient up)
Pulmonary ventilation (if doing badly)*
Morphine used even in the absence of infarction?
To treat severe pain.. Morphine is powerful analgesic.
Yes, but in which cases other than MI, pain is a significant symptom?
Post surgical pain, Cancer pain.
Morphine is indicated in only acute stabbing visceral pain. Except in abdominal emergency's.
Abdominal emergencies if due to biliary spasm. Give nitrous oxide. Or else pethidine.
Even for abdominal pain, if it's severe once after the examination of abdomen.
No, we don't use morphine in abdominal emergencies.
I think we do apart from biliary conditions.
Posting this again, since it's relevant. Opioids, morphine mnemonic http://medicowesome.blogspot.ae/2014/04/opioids-and-other-analgesics-mnemonic.html
Biliary spasm is due to contraction of sphincter of Oddi. Right?
Yep.
Is morphine used alone in biliary spasm??
No, no. It's specifically contraindicated in acute abdominal pain. Because it cause biliary spasm.
Yes, but if used along side of some particular drug it releives spasm.. What drug is it??
I think it's atropine.. Is that right?
Yes!
Atropine is used with morphine for treatment of renal and biliary colic.. Morphine alone may aggravate pain by causing spasm of sphincter of oddi.. Atropine relaxes the smooth muscle of gallbladder and increases the intrabiliary capacity and counteracts the spasmogenic effect of morphine..
I was asked this in a viva, why is atropine given before procedures like drainage of pleural effusion aka pleural tap?
Ummm don't know!!
Okay, I'll give you a hint.. What will happen when you push the needle into the patient
Bleeding?!
And?
Bleeding is minor, think of other things!
Atelectesis?!!
Think Neurologic.
Shock?
Yep. Vasovagal shock. That's why atropine is administered half an hour before the procedure.
Oooh.
Wow! Didn't know that!!
This should apply to all procedures then!
Yes, all procedures. But I was asked this specially because my case in finals was pleural effusion.
Thanks IkaN!
Study group discussion: Central trachea in pleural effusion
In which pleural effusions the trachea is central??
Bilateral ??
Okay.. But in which unilateral conditions?
Due to bronchogenic ca?
When there is pull + push of trachea, nullifying it?
Umm.. It's because of mesothelioma
Why?? I mean why specifically I'm mesothelioma?
If pleural effusion is because of mesothelioma then the negative pressure created by it doesn't effect that much... Sorry.. Don't know exactly.. I'll let you know..
In absorption collapse such as in bronchiogenic ca or foreign body impaction,
Bronchus is obstructed, intrapleural pressure remains negative and trachea is shifted to the same side.
In cases of compression collapse due to pleural effusion, pneumothorax or hydropneumothorax,
Bronchus is patent, intrapleural pressure is positive n so trachea is pushed to the opposite side.
So, if there is bronchogenic ca with pleural effusion, both mechanisms take place,
If pulling effect by bronchogenic ca plays more, trachea remains on the same side of effusion.
If both plays equally, trachea remains in central
Ah.. Push and pull which I mentioned earlier. Thanks a ton!
Study group discussion: Scissoring posture
1 and a half year old child when suspended by the axillae, his legs maintain scissoring posture. What can you think of?
Cerebral palsy!
Or UMN lesion!
Which type?
Spastic diplegia
What is the reason for such kinda posture?
Scissoring is a sign of hypertonia.
Patient tone is increased!!
Yes
Everything related to UMN lesion
Spasticity, hyper reflexia, upgoing plantar.. You will see in this patient!
What can be the possible treatment?
Baclofen + physiotherapy.
A pillow or ball between the legs while sleeping!
Yeah, baclofen will relieve the spasticity.
Study group discussion: Cutaneous signs of insulin resistance and lipoproteinemia
These are skin tags. What do you think of when these are present?
Aren't these harmless with no associated risk?
Nope. They represent something! Ok! These are signs of insulin resistance!
What are other cutaneous signs of insulin resistance?
Acanthosis nigricans
Yes!!
One more.. Although that one is associated with hyperlipidemia too.
Xanthelasma?
Yes!!! Xanthelesma.
Since we are on hyperlipidemia http://medicowesome.blogspot.ae/2013/08/how-to-remember-lipoprotein-disorders.html
So cutaneous signs of insulin resistance include:
Skin tags
Acanthosis Nigricans and
Xanthelesma
Mnemonic: SAX!
In which condition do you see orange tonsils?
Rifampicin intake?
Haha nope. It's related to the topic.. A high cholesterol condition!
Lol no idea then!
Tangier disease.. It's due to lack of cholesterol transporter gene. The disease is characterized by atherosclerosis, hepatosplenomegaly, polyneuropathy and orange tonsils.
Ohh!!!
Another review question.. Why is type 1 lipoproteinemia associated with pancreatitis?
Short of knowledge on this topic maybe someone else would answer it?
It's because chylomicrons obstruct the pancreatic duct.
Sunday, March 1, 2015
Study group experience #13
Ligamentum venosum and ligamentum arteriosum
Uncouplers of oxidative phosphorylation
What does emulsification mean in fat digestion
Parasites that cause carcinoma of the gall bladder
How and when do children understand the concept of death
Abnormal breath sounds: Crackles, Wheeze, Rhonchi and Stridor
CHARGE syndrome and related case
Pfeiffer disease and Pfeiffer syndrome
Fontanelles and thyroid hormone
Neurological emergencies and isoniazid overdose
Medial medullary syndrome and crossed paralysis
Locked in syndrome and total locked in syndrome
Marcus gunn jaw winking syndrome and Ptosis
Relative afferent pupillary defect (Marcus Gunn pupil) vs Optic nerve lesion
45 centimetres in length and tubes
To vaccinate or not to vaccinate
Non contraceptive uses of condom
Drug causing hypertrophic pyloric stenosis
Low molecular weight heparin vs unfractionated heparin
Cool fact about GLP 1 agonists
Phew! That was a lot, was it not? So much more to come! I could create a separate blog for these xD
We also reached 100 awesomites in group 2! Yaay!
Which also means new comers will have to wait till there are enough awesomites to form group 3. Sorry for the delay!
Study group discussion: Relative afferent pupillary defect (Marcus Gunn pupil) vs Optic nerve lesion
*A picture was posted on the group on which this discussion took place.
Description of the picture for the readers convenience:
In the first picture, we see normal pupils.
In the second picture, light is shone in the left eye. Right and left pupil constrict.
In the third picture, light is shone in the right eye. Right and left pupils do not constrict.
In the fourth picture, light is again shone on the left eye and again, both pupils constrict*
RAPD?
Also know as Marcus Gunn eye!
Aka prostitute's pupil :P
Nope. Optic nerve is affected on the left side. As there are absolutely no afferents from left eye, indirect is absent.
Yes.. The 3rd nerve efferent is intact and optic nerve is affected.
There is crossing of the afferent fibres of each eye. That's why when you stimulate one eye the other eye also dilates via the efferent fibres. That's how the other eye also constricts (indirect). In this picture, there is complete afferent defect. The optic nerve is completely transected.
Why not RAPD?
In RAPD, when light is shone to the diseased eye, direct absent.. Therefore, doesn't constrict.
Mnemonic: Direct Diminishes in a Diseased eye, indirect present.
RAPD is diagnosed by swinging light test. When you alternate the flashlight.. The affected pupil ( less number of afferent fibres ) has a release phenomenon and dilates instead of constricts. The affected pupil initially constricts..But when you swing the flashlight repeatedly it dilates. The pic hasn't shown frequent swinging. And the pupil remains dilated in the first go when the light is shown. So there is no relative afferent defect.
I haven't heard of the release phenomenon, I've thought it's because relative to the normal eye, the disease eye appears to dilate. It always constricts but because you compare it with the normal eye, it seems to dilate.
But why do we call it relative? The direct being present and the indirect being absent?
I dont think we call it relative cause efferent is intact. We call it relative cause, relative to the normal eye..The affected eye has reduced optic nerve fibres. This is done to detect early loss of fibres in optic neuritis.
I'm such type of patient. I mean my left optic nerve is affected.
Really? How were you diagnosed and when?
I met with an accident. It was a severe injury on left eye. 3rd nerve got damaged at first. Doctors said it's severe. It will heal with time. But doctors were not sure it will heal completely or not.
Oh I'm so sorry!
Can you see?
After 1 yr, I again went for checkup.. Doc said 3rd nerve is alright now but optic nerve is affected due to increased stress. Now, I have only partial vision left eye. It's 6/24 (Normal is 6/6)
And it'll not heal completely for whole life.
Optic field shows that the person can't see through different angles with the defective eye. That's why, it's called Partial Vision.
Because of damage to optic nerve.. Healing depends upon the degree of damage. Meconerv Forte is the medicine for that.. But chances of complete healing are rare..
Difficulties make us more strong! Just keep going no matter what.
Yeah, of course. Thanks!
Saturday, February 28, 2015
Study group discussion: Marcus gunn jaw winking syndrome and Ptosis
Interesting one - congenital ptosis associated with winking motion of the affected eyelid on the movement of the jaw. Known as Marcus gunn jaw winking syndrome.
On opening, side ward movements of jaw, increase of palpebral aperture!
Usually jaw movement to opposite side! Jaw winking.
What are the causes of Ptosis?
Neurologic causes of Ptosis include Horner's syndrome, in which the pupil is constricted, and third nerve palsy, in which there are abnormalities of eye movements and the pupil may be dilated. Local causes include congenital and acquired disorders of the levator muscle complex and tumors and infections of the eyelid. Myasthenia should always be considered.
Study group discussion: Medial medullary syndrome and crossed paralysis
B. Horners syndrome
C. Ipsilateral 12th cranial nerve palsy
D. Contralateral pyramidal tract sign
Study group discussion: Water intoxication syndrome
Water intoxication syndrome! I remember this from first year physiology!
How does water intoxication syndrome work? How much water does the person have to take?
The water that causes intoxication is mostly through intravenous fluids. I doubt a human being would have the capacity to drink enough water to cause an intoxication orally. I have heard of psychiatric disorders associated with a high water consumption though.
But if you're looking for a number - it's 16 ml/min
If you consume that much in any amount of time, you'll have exceeded intake more than the maximal urine flow.
Ummm, got it! it makes more sense than what I was thinking hahaha
Surely, drinking too much water would cause vomiting or something before the body would allow itself to become intoxicated?
Or massive impermeability of the kidney nephrons?
Does drinking too much water cause vomiting? How permeable is the upper alimentary canal to water? Could a large amount of water be absorbed before it reaches the stomach?
Too much water does cause vomiting! The most common symptoms suffered by this group were changes in mental status, emesis, nausea, and seizures. Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770067/
I think there have been documented cases of people drinking enough water to die. I imagine it's very difficult, though, and therefore rare.
Mostly psychiatric patients.
Water intoxication also occurs in SIADH and surgical trauma.
Risk factors include low body mass (infants), endurance sports, competitive drinking or latrogenic.
Treatment normally follows strict fluid restriction. In more serious cases, diuretics or vasopressin receptor antagonists are given.
Similar to SIADH treatment!
You know the artist Andy Warhol? He died of water intoxication!
Oh.
Study group discussion: Drug therapy for asthma
Which is the physiological antagonist of histamine?
Acetylcholine?
No.
It's ephedrine or adrenaline.
Which are the classes of drugs used for acute control of asthma?
B 2 agonists.
Epinephrine.
Yes, epinephrine.. But that too comes under b2 agonist.
Steroids?
No, steroids is for long term control
Two more classes of drugs!
Methylxanthine? Theophylline!
Montelukast?
Ipratropium!
Yup. Second class is theophylline or aminophyline. The third class is anti-cholinergics.
But not montelukast..That's also for chronic use.
What is the function of montelukast?
Leukotriene receptor antagonist!
Leukotrienes when binding to their receptors it cause bronchoconstriction. Monteluekast used in maintenance therapy of asthma. But not useful in acute exacerbation.
Mast cell stabilizers, that is, ketotifen and sodium chromoglycate?
Mast cell stabilizers are also chronic for use.
And IgE antibody? Omalizumab?
That too for chronic use.
Even MgSO4 is used in acute management of asthma.
Yup.
Next one.
Why does use of aspirin cause asthma?
Arachidonic acid forms two type of substances via the cyclo-oxygenase and lipo-oxygenase pathways. Aspirin inhibits the cyclooxygenase pathway.
Hence, all of the arachidonic acid gets diverted to lipo-oxygenases.
And if you remember L4, B4 are the major mediators of acute attack of asthma.
Oh yeah.. That's why leukotriene antagonists are used, they inhibit LT C4 , D4
Exactly.
There are the major cause of bronchoconstriction!
As cyclo cycle is inhibited..arachidonic acid is used more in lipo cycle!
LT antagonists act on cysLT1!
Study group discussion: Low molecular weight heparin vs unfractionated heparin
Something regarding heparins! So which one is better to use? LMWH or UFH? Why?
LMWH (Low molecular weight heparin)
Why?
Less incidence of thrombocytopenia with LMWH!
Better bioavailability, t1/2 , APTT not affected.
Right. Why APTT not affected?
Because LMWH has more predictable pharmacokinetics and anticoagulant effect, LMWH is recommended over unfractionated heparin for patients with massive pulmonary embolism.
Because LMWH acts only on AT3... Does not have the scaffolding effect of UFH.
On which part it doesn't act?
LMWH doesn't affect on thrombin..
Yes! That's the answer!
LMWH acts on AT3 only and doesn't affect thrombin.
UFH acts by 2 mechanisms
1. On AT3
2. By providing a scaffolding on which AT3 can interact with Thrombin
In LMWH, the second effect is absent, hence less interference...
Yes!! Correct!!
Which situation you would prefer UFH?
For cardiac surgeries, UFH is preferred as it can be titrated dose - by - dose with protamine sulphate.
Cardiopulmonary bypass.
Why?
Cardiopulmonary bypass....Because it's effects can easily be reversed fully by protamine. And its more effective.
Exactly! Any conditions with high risk of bleeding we prefer UFH.
Yep. Cause we will be able to reverse if we give more heparin by giving protamine sulphahte same is not possible with LMWHs.
Why?
Because action of LMWH cannot be reversed completely..
Yes, correct. It's because of the molecular weight.
So which test would you like to do before deciding whether to give UFH or LMWHs?
Any other conditions?
Ok so in cases of advanced renal failure UFH are preferred over LMWHs
Now tell me why?
No idea.. Please explain!
So we would check creatinine before starting heparin
This was the test I was taking about! LMWHs are excreted renally.
Right...UFH is metabolised by liver
On the other hand UFHs are cleared by reticuloendothelial system.
Good work guys! Hope it helped!
Yes, thanks a lot!
What about pregnancy?
Are UFH still preferred or do you give LMWH?
The major limiting factor is the cost or HIT. Heparin is still ruling the world and saving millions of lives.
Also i heard..senior doctors still prefer UFH, inspite of LMW
Ummm!! I would say LMWHs are much better!! Many trials have proved that! It's only in certain scenarios that UFHs are preffered. Nobody wants to keep monitoring APTT so just making the life easy LMWHs are good!!
Yeah. But they are more experienced in using UFH.
This was told by our residents. If a senior external asks you whether UFH or LMWH is better.. Be diplomatic in your answer.
Ohh! Yeah that can be the thing!
Updated later:
And also an addition to a previous discussion on oral anti-coagulants. Why heparin is given for the initial 5 to 7 days, when warfarin has already been started?
One reason is the preformed coagulant factors need to get depleted before warfarin starts taking effect. The other reason is that in the initial days warfarin acts as a prothombotic. Cause it depletes protein c and protein s!
Study group discussion: Fixed specific gravity
What is fixed specific gravity? Like what is the cause?
Because of renal failure, the remaining functional nephrons undergo compensatory structural and hypertrophic changes,these compensatory changes result in urine that is almost isotonic with plasma. Therefore, a patient experiencing renal failure will present with specimens measuring the same, or fixed, specific gravity regardless of water intake
Thanks! Is there any value associated with it? Numerals?
Low specific gravity in renal failure, which results in a fixed specific gravity is between 1.007 and 1.010.
Study group discussion: Fluoroquinolones
Fluoroquinolones with
maximum phototoxicity - sparfloxacin
100% bioavailibity - pefloxacin
Highest efficacy against tuberculosis - moxifloxacin
I don't know what is the meaning of 100 % bioavailability.
100% bioavailability means no first pass metabolism. Usually achieved on IV administering.
Study group discussion: Beta blockers
Give me two reasons why..you don't give beta blockers to diabetics.
They mask the hypoglycemic symptoms
First reason correct.
Hint - It is something to do with the liver and beta 2 receptors.
Glycogenolysis decrease.
Yup..The beta 2 receptors stimulate the glycogen breakdown and glycogenolysis.
So if you give a nonselective beta blocker.. Not only will the patient not feel the coming signs of hypoglycemia but also the liver will fail to release glucose in the blood.
Side effects of beta blockers?
Bradycardia
Breathlessness is due to bronchoconstriction
Rise in lipid level
Why won't you prescribe a beta blocker to a young man?
Sexual distress? Not sure!
Sexual dysfunction..Correct!
Vivid dreams and insomnia, and sexual dysfunction is due to beta blockers central action on the brain. They cross the blood brain barrier.
In which type of arrhythmias are beta blockers especially indicated?
The ones atrial in origin.
In which type of arrhythmia beta blockers are contraindicated?
Heart blocks.
Why so?
Cause they reduce the heart rate further.. A side effect of beta blockers is to decrease AV nodal conduction and precipitate asystole. In other words, they increase the refractory period of AV nodal cells.
Study group discussion: Locked in syndrome and total locked in syndrome
What's locked in syndrome and total locked in syndrome?
The patient is conscious, well oriented to time, place and person but is unable to carry out any voluntary movement along with loss of reflexes. Everyone else thinks the patient to be in a comatose / coma state.
Some retained cranial nerve reflexes with eye movements to communicate with no limb movement.
Yes! But in total locked in syndrome, there's no eye movement.
In locked in syndrome, I think patient communicates through blinking of eyes.
Yes. But in total locked in syndrome, they cannot.
Study group discussion: Cool fact about GLP 1 agonists
Antidiabetic derived from lizard?
It's exenatide! GLP-1 agonist.
From the gila monster, is it?
Exactly!
Is it not given orally?
I hope not
No.. Parenteral.. Subcutaneous!
Also there are extended release of exenatide available. Taken as weekly injections.
Bydureon! Weird but true! Thank you!
Study group discussion: Drug causing hypertrophic pyloric stenosis
Exposure to which drug leads to infantile hypertrophic pyloric stenosis?
Hint: One of the macrolides.
Erythromycin?
Yeah, they have found the association in the research that was conducted!
http://www.ncbi.nlm.nih.gov/m/pubmed/12090829/
If administered in the infant, can cause hypertrophic pyloric stenosis. Within 15 days of life, that is.
Interesting.
Study group discussion: Non contraceptive uses of condom
areas. Strange but interesting fact!
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!
Friday, February 27, 2015
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!
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!
Study group discussion: To vaccinate or not to vaccinate
Something about influenza vaccine!
So 6yrs old child comes for influenza vaccine! Allergic to egg! Develops rash with the eggs! Will you give him the vaccine or not?
Why yes or why no?
Yes. Because the new ones are not produced in eggs, right?
They're subunit/recombinant/ts vaccines.
If it's an egg based vaccine, you can give a test dose and check keeping adrenaline ready.
My friend had allergy to egg. Last year when we went to take influenza vaccine, she wasn't given it.
Because it's not an important vaccine / you can do without it?
She has stomach pain on eating eggs..No rash or anything.
Yes, it's a controversial issue! Though earlier their used to be strict contraindication to egg allergy. But with the egg allergy with rash, they say it's ok to administer with an observation period of 30 minutes after the vaccine is given.
On the other hand if patient had anaphylaxis reaction then the vaccine can still be administed but under the consultation of the specialist in the allergies.
There is difference in the usage of live vs inactivated vaccine!
Egg allergic are given the inactivated one!
I found two papers let me send the links here
http://www.ncbi.nlm.nih.gov/m/pubmed/23805959/
http://www.ncbi.nlm.nih.gov/m/pubmed/23176882/
So you can give it (:
How about MMR vaccine should that be given in Egg allergy?
If you can flu, you can obviously give MMR. Plus, measles is a severe disease so I think yes.
Yes, it is not a contraindication. Very low risk for anaphylaxis as these contain only small amount of egg cross reacting proteins!! These two are the ones commonly tested.
The quantity of egg protein in a dose of MMR vaccine is approximately 40 picograms (much lower than in influenza vaccine, which contains approximately 0.02-1.0 micrograms), and this is believed to be associated with a much lower risk.
Source: Wiki
What vaccine can have an inconsolable screaming reaction to it? (>3hours)
DPT ... Due to the pertussis component.
Aha. Okay.
I have another vaccine related review question!
If a child develops convulsions after receiving his DPT shot, what will you do? Will you give him the next shot?
I would say no! Anaphylaxis as well as encephalopathy are contraindications to the next shot?
This is a trick question - The convulsions occur due to the pertussis component of the vaccine.
So you will give the vaccine, but you'll give acellular pertussis instead or just give DT in the next dose.
They are life threatening diseases and it's important that the kids get vaccinated.
Ohhh!!!!
Was my viva question! (Also one of the rare instances when I knew the answer :P )
Study group discussion: Chagas disease
What comes to your mind when you hear of left ventricular apical aneurysm?
Two apical impulse.
Hint: Protozoa.
Chagas disease.
Brilliant!
Chagas disease causes destruction of the neural crest cells, right?
I know it causes Hirschprung disease. But how come apical aneurysm?
I think some parts of the heart are also formed from the neural crest cells.
The aorticopulmonary septum!
Chagas disease is associated with dilated cardiomyopathy.
I've heard of that.
Related fact: Chagas also causes achalasia.
Thursday, February 26, 2015
Study group discussion: How and when do children understand the concept of death
2- Being final
3- Being in a long journey
4- Being temporarily separated from parents
5- No understanding of death.
Since the child was diagnosed with neuroblastoma, he will be able to understand that death is final, but will be unable to understand his possibility of death.
Study group discussion: Alcohol and sex
This my viva question.. The boldest I have come across. The external asked me how does alcohol affect one's sexual performance. I went through 50 shades of red within a minute!
Haha. I think it decreases sexual performance.. As in erection. I'm not sure though. Heard it somewhere.
I said, it increases the desire but decreases the performance.
He quoted a line by Shakespeare then!
Alcohol causes loss of libido.
Sexual dysfunction in the alcoholic may be due to the depressant effect of alcohol itself, alcohol-related disease or due to a multitude of psychological forces related to the alcohol use. The spectrum of sexual dysfunction encompasses:
Decreased sexual desire—persistent or recurrent deficiency or absence of desire for sexual activity giving rise to marked distress and interpersonal difficulty;
Sexual aversion disorder—persistent or recurrent aversion and avoidance of all genital sexual contact leading to marked distress and interpersonal difficulty;
Difficulty in erection—recurrent or persistent, partial or complete failure to attain or maintain an erection until the completion of the sex act;
Difficulty in achieving orgasm—persistent or recurrent delay in or absence of orgasm, following a normal sexual excitement phase;
Premature ejaculation—persistent or recurrent ejaculation with minimal sexual stimulation, before, on or shortly after penetration and before the person wishes it, which causes marked distress.
Alcohol abuse is the leading cause of impotence and other disturbances in sexual dysfunction.
Thanks!