Dextrorotary or levorotatory and D or L forms - We hear these terms, especially, in biochemistry of chiral carbon atoms.
Now, I always thought in D-glucose, the D is for dextrorotary. But I was wrong.
Hey guys!
As you all know, I'm preparing for USMLE and I wish to do an Internal Medicine residency in the USA. A part of the process for international medical students requires electives, which is, clinical experience in the US.
I am in Cleveland, Ohio in the months of January - April 2016 for my electives.
I will also be coming to Houston, Texas for my USMLE Step 2 CS exam.
If you're around at that time, I would love to meet you. Please come say hi.
For those of you who have been to the US for electives, please let me know do's and dont's. Anything you wish someone had told you prior to the experience.
I will also be blogging about every tiny detail - From preparation to what I experienced - So that it helps someone like me in the future :)
That's all!
Wish me luck and pray for me.
-IkaN
PS: I will not be disclosing the name of the hospital and specialty on the blog. Reason being patient confidentiality and privacy purposes.
Why do patients with multiple sclerosis experience worsening of neurological symptoms after heat exposure, that is, after taking a hot bath or after exercise?
It's known as Uhthoff's phenomenon.
Uhthoff's phenomena is due to ion channel modifications, in conjunction with thermoregulatory derangements that occur in MS, transiently altering the conduction properties of demyelinated axons.
This is from uptodate:
Heat sensitivity — Heat sensitivity (Uhthoff phenomenon) is a well-known occurrence in MS; small increases in the body temperature can temporarily worsen current or preexisting signs and symptoms.
This phenomenon is presumably the result of conduction block developing in central pathways as the body temperature increases. Normally, the nerve conduction safety factor decreases with increasing temperature until a point is reached at which conduction block occurs; this point of conduction block is reached at a much lower temperature in demyelinated nerves.
(This was discussed on our study group.)
Study group discussion: Why does ciprofloxacin cause tendinitis or tendon rupture?
The exact pathophysiology of FQ-induced tendinopathy remains elusive; however, some concepts have been suggested:
FQ: Fluoroquinolones
1. FQs are synthetic antibiotics that act by inhibiting bacterial DNA gyrase (topoisomerase II). DNA gyrase is directly involved in DNA replication and cell should not exert a negative effect on human cell lines because the affected bacterial enzymes have little homology with mammalian DNA gyrase. However, it is possible that FQs have a direct cytotoxic effect on enzymes found in mammalian musculoskeletal tissue.
2. FQs have chelating properties against several metal ions (e.g., calcium, magnesium, aluminum), and have been known to cause direct toxicity to type 1 collagen synthesis and promote collagen degradation.
3. Animal studies have shown that FQs cause cartilage damage by inducing necrosis of chondrocytes (36 hours after treatment), disruption of the extracellular matrix, and formation of vesicles and fissures at the articular surface.
(This was discussed in our study group)
Some review questions on drug induced pancreatitis!
Which diuretics can lead to pancreatitis?
Thiazides and furosemide
Which Antiretroviral drugs can lead to pancreatitis?
Didanosine and stavudine
Which antibiotics can lead to pancreatitis?
Metronidazole and tetracyclines
Seizure med leading to pancreatitis?
Valproate
Immunosuppressive drugs leading to pancreatitis?
Azathioprine
L asparaginase
Ok the last one.. Drugs for treatment of IBD leading to pancreatitis?
Sulfasalazine
5-ASA
(Mnemonic, if you need one)
FAV DAM - ATiTiS
Furosemide, Azathioprine, Valproate
Didanosine, Asparginase, Metronidazole
ASA, Tetracycline, Thiazides, Stavudine, Sulfasalazine.
Hello everyone!
I see a lot of patients in the casualty with fever, chills & thrombocytopenia but to my surprise, they've been diagnosed with malaria (Instead of dengue). I was wondering what the mechanism is.
The speculated mechanisms leading to thrombocytopenia are: coagulation disturbances, splenomegaly, bone marrow alterations, antibody-mediated platelet destruction, oxidative stress and the role of platelets as cofactors in triggering severe malaria.
In uncomplicated cases of malaria, thrombocytopenia is the result of splenic pooling of platelets aggravated by a moderate decrease in platelet life span.
That's all!
-IkaN
Mini bacteriology post! Yaay!
In which Lancefield group does Streptococcus pyogenes and Streptococcus agalactiae belong? How do you remember them?
Streptococcus Pyogenes belongs to Lancefield Group A mnemonic:
I remember GAP jeans (Because of the gap company manufactures amazing clothes) - Group A Pyogenes.
Streptococcus Agalactiae belongs to Lancefield Group B mnemonic:
Remember B for Baby. Streptococcus Agalactiae causes meningitis in babies and belongs to Lancefield Group B. Babies also love Galaxy chocolates and stars.
That's all!
-IkaN
I was reading Atrial fibrillation today and thought I'd write a small quick review blog on it.
A patient with atrial fibrillation will usually present with palpitations or fatigue.
On physical examination, irregularly irregular pulse is characteristic.
ECG is diagnostic.
Extra tip: Your patient may have his rhythm well controlled when you see him in the wards and you might not have the characteristic physical finding of an irregular pulse or have an ECG in hand. In that case and especially during vivas, do mention that you would like to rule out other causes of fatigue by ordering CBC, SE & LFT.
CBC: Complete blood count
SE: Serum electrolytes
LFT: Liver function tests
In an acute setting, you must provide symptom relief through rate control. Beta blockers, calcium channel blockers are preferred. Digoxin is considered if blood pressure is low.
Fun fact: Why isn't Digoxin an awesome drug for rate control in exercise and anxiety?
Because the increased rate in exercise and anxiety is primarily due to adrenergic stimulation and Digoxin works through Vagal stimulation.
You need to rule out reversible causes of atrial fibrillation like electrolyte imbalance, thyrotoxicosis, fever, alcohol and drugs. Always order TSH levels.
Extra tip: Also ask for a history of snoring since sleep apnea is a treatable cause of atrial fibrillation.
Rate control is usually done first since it mitigates symptoms. Rhythm control is preceded by measures to reduce stroke, which includes either 3 weeks of anticoagulation by dabigatran / warfarin or clot exclusion by TEE.
CHADS2 score is used to decide whether anticoagulation is required. It is based on risk stratification.
Dabigatran is preferred over warfarin because INR monitoring isn't required. However, it is expensive, contraindicated in renal failure and there is no reversal in major bleeding.
Electric cardioversion or chemical cardioversion may be done depending on patient symptoms.
Drugs used for chemical cardioversion are: Flecainide, Ibutelide, Procainamide, Amiodarone.
Curative catheter ablation may be tried in patients who have recurrent atrial fibrillation and in whom antiarrhythmic drug trial has failed.
Cool fact: Propafenone is "pill in pocket" drug used by patients when they feel onset of palpitations. It is used in conjunction with beta blockers to prevent fast dysrhythmias.
Here are a few mnemonics I got online:
Precipitants / causes of Atrial fibrillation: PIRATES
PE, Ischemia, Respiratory diseases like COPD, Atrial enlargement or myxoma, Thyroid, Ethanol, Sepsis or Sleep Apnea
Mnemonic for determining major risk of bleeding: HAS BLED
HTN, abnormal LFT / RFT, Stroke, Bleeding history, Liable INR, Elderly, Drugs that predispose to bleeding.
If score >3, higher risk of major bleeding.
That's all!
-IkaN
Related post: Antiarrhythmic drug classes mnemonic
Greetings everyone!
Here's a mini fact: Christmas tree rash is seen in Pityriasis rosea.
That's all!
Merry Christmas everyone!
-IkaN
Related post: Christmas disease mnemonic
What is the reason for pruritus and itching in obstructive jaundice?
Patients have differing sensitivities to elevated bile salt concentrations,
which act on peripheral pain afferent nerves to produce the sensation of itching. This stimulation involves
opiate-mediated pathways, and opiate antagonists can block cholestasis-associated itching.
Itching does not appear to be associated with histamine release, and antihistamine therapy is generally ineffective.
Ultraviolet B phototherapy has been successfully used to treat pruritus.
Thanks for explaining the mechanism to us, Benedict!
Hello.
Battles sign is ecchymosis over the mastoid process and is mostly indicative of a fracture of the skull.
Mnemonic:
Battle Sign
Bruises Seen
Basilar Skull fracture
I love this mnemonic posted online too: BattlE - Behind Ear.
That's all!
You're a warrior.
-IkaN