Why does thiazide, a diuretic, cause a paradoxical anti-diuretic effect in Diabetes insipidus?

Hey everyone!

I have explained this before (In one of my earlier posts on free water clearance) but someone found my language too complicated to understand. So I decided to write this post.. An explanation which is "free" of complicated terms like free water clearance. Yaay! :D

ADH absorbs water. In nephrogenic diabetes insipidus, the kidney is unresponsive to ADH.

What do you then?

You use a drug called thiazide.

Thiazide diuretics inhibit the NaCl co-transporter  in the renal distal convoluted tubule (DCT).
The DCT is water impermeable.. So the DCT action is NOT how thiazides preserve water.

Then what is preserving water?

Submissions: Mature defense mechanisms mnemonic

Mature defense mechanisms mnemonic

SMASH
Suppression
Mature defenses
Altruism
Sublimation
Humor

This mnemonic was submitted by mist amidst

Ethosuximide mnemonic

Greetings everyone!

This little pharmacology pearl was written by Keto :)

eThosuximide is the T drug.

It blocks the T-type Ca2+ channels:
T stands for Transient which can be found in the Thalamus.

Remember, that thalamus is a relay nucleus with a lot of subnuclei. Everything travels through, EXCEPT smell. So a patient with "Transient" absence (peTiT mal) seizure, you can let them smell something to bring them back. And... eThosuximide is the drug they need.

Study group discussion: Monroe Kenri's Law

Here's a cool fact:

Monroe Kenri's law states that cerebral perfusion pressure = Mean blood pressure (MBP) - Intracranial pressure (ICP)

Hence, in cases of increased ICT or intrcranial heamorrhage, BP rises.
This is physiological so that blood supply to the brain can be maintained.

Hence, in cases of stroke, never try to reduce BP unless it is above 200. If you reduce BP, the blood supply to brain is compromised.

Cushing's triad in cases of increased ICT:
1. Increased BP
2. Bradycardia
3. Irregular respiration.
(Because increased ICP compresses the brain stem)

Related post: Cushing's triad (How to make medical notes)

Bleomycin metabolism

This is a short post on pharmacology!

Bleomycin is inactivated by a cytosolic cysteine proteinase enzyme, Bleomycin hydrolase.

This enzyme is widely distributed in normal tissues with the exception of the skin and lungs, both targets of Bleomycin toxicity.

This is why, Bleomycin causes pulmonary fibrosis.

It's also why bleomycin is used in skin cancers like squamous cell cancer.

That's all!

-IkaN

Hyperphosphatemia in chronic kidney disease

This is a really short post :D

What's the mechanism behind hyperphospatemia in kidney disease?

Kidney activates vitamin D.

Tarsal Bones Mnemonic

Hey guys, Jay here once again. Today I was studying my anatomy, and our lower limb region is going on. Since our regional exam is next week, I wanted to study the foot and especially the tarsal bones. Me, the one who is so fond of mneumonics, tried finding some mnemonic to remember the tarsal bones. I found one on internet I made one myself. So let me first list the tarsal bones.
1. Calcaneous
2. Talus
3. Navicular
4. Medial cuneiform
5. Intermediate cuneiform
6. Lateral cuneiform
7. Cuboid

The one on Internet:

The Circus Needs More Interesting Little Clowns

But in this Calcaneous and Talus have exchanged places. So when I saw this, I edited it a bit. :) So it kinda goes with the first syllable as well. ^_^

CaT Navy Meets Interesting Little Cubs

CaT has Calcaneous and Talus both.

Hope it helped Awesomites. :) Until we meet again then, Ciao!! Au revoir!!! :D

《Jay》

Heart murmurs mnemonic

Hello people with a pumping heart in their chests, obviously! <3

In this post, I'll be taking about the few mnemonics I use in relationship to murmurs.

"PASS" is a good mnemonic for remembering that pulmonic and aortic stenosis give a systolic murmur.

The opposite of PASS, ie, other two valves and the other defect gives a systolic murmur too. (Mitral and tricuspid regurgitation gives a systolic murmur!)

VSD has a S so that's systolic.

Now, the other ones - pulmonic and aortic regurgitation, mitral and tricuspid stenosis will cause diastolic murmurs :)

Here's another mnemonic submitted by one of the readers:

Primary, secondary and tertiary hyperparathyroidism mnemonic

This idea was submitted by Keto. It helps go through Calcium and Phosphorous levels very quickly.

The values are somewhat logical and can be thought through.. But if you're on ward or on a board exam this can be handy.

Hyperparathroidism mnemonic

Why is there an increased white cell count in sickle cell anemia?

Hello sweet people!

I spent today's free time searching for what is the cause of leukocytosis in sickle cell anemia =P

Sickle cell disease typography

Making Referrals - Bio Medical Ethics

Hey awesomites, I'm Jay, and I'm your new Medicowesome contributor! yayy!! :) And today we are going to talk about Referrals. This is another important ethical responsibility of a physician.

A physician’s Central responsibility is WELFARE OF THE PATIENT, and that means, Physician should work for the best interest of the patient not him/herself.

Referral simply means that, when we reach the boundaries of our competence, we should hand our patient to a more competent physician. Keeping a patient with ourselves to hide our incompetency or to earn more money is a huge NO-NO!!!

We shouldn’t be ashamed to ask for help from our colleagues, and we shouldn’t be continuing to treat a patient, if we cannot give him/her a fruitful therapy as our boundary of competency has reached. That’s when we should write a LETTER OF REFFERAL to a Consultant(BritE)/Attending(AmE) Physician or to another colleague with a broader knowledge or idea of the subject.

Submissions: Bio medical ethics

Bio Medical Ethics - by Jay ™

Today’s blog post is about Bio Medical ethics or Ethics of Medical care that a health care practitioner has to adhere to.

Medical ethics started off as Hippocratic Oath made in 460~ BC in the Book called Corpuz Hippocratum.

“Do No Harm” is the Primary Ethical concern of Medical Ethics. 

Constitutional pancytopenia mnemonic

Constitutional pancytopenia mnemonic

Rich in name, poor in cells.

"I fancy this carat (gold), diamond and silver man. He is a mega rich noob down here!"

Fancy: Fanconi syndrome
Dis (Dys) Carat: Dyskeratosis congenita
Diamond silver man: Shwachman Diamond syndrome.
A mega: Amegakaryocytic thrombocytopenia
Noob: Noonan syndrome
Down: Downs syndrome

That's all!

The mnemonic is just as hard xP

-IkaN

Study group discussion: Drunken crab syndrome

Which parasite causes the drunken crab syndrome?

Paragonimus westermani.

Drunken crabs, because man gets infected with it by eating raw crabs. In Taiwan, these crabs are marinated in wine. Hence, the name!

Also called kejang.

Wow I didn't know this.

Nice to know, I was formulating all sort of weird possibilities for symptoms based on that.

I thought of a motion abnormality.. Since crabs can walk sidewise.

When I first came across this... Even I thought that the person would have a drunken gait or something!

Wonder how a crab would walk in cerebellar ataxia.. Considering they have a cerebellum.. Or not!

Lets talk about crabs!

Crabs is also slang for STD.
It's not slang, my bad. It's lice in pubic hair. Also known as crab lice.

CRAB is used for Multiple Myloma symptoms too.
CRAB:
C = Calcium (elevated),
R = Renal failure,
A = Anemia,
B = Bone lesions

And then there's Krabbe's disease, some sort of leucodystrophy.

Lame mnemonic for drunken crab.. Our teacher said -- Mr. Krabs gets drunk in Taiwan .. Because he found out.. His daughter "P"earl  (paragonimus) is a man (westermanii)

Nice mnemonic!

Typhoid: Leukopenia, chronic carrier state and cancer (Why does typhoid fever cause leukopenia?)

I see a lot of patients with typhoid in the casualty and usually, they all have leucopenia. So I wondered - Why does the WBC count decrease in typhoid or enteric fever? Why does the WBC count become low unlike other infections?

After loads and loads of Googling, I found the answer to my question.

Study group discussion: Acromegaly

What is the most common cause of death in patient with acromegaly?

Cardiomyopathy leading to heart failure.

Why is diabetes more common in acromegaly?

GH has anti insulin effect.

Cool fact: GH increases insulin production. But at the same time causes insulin resistance.

How can you find out by giving glucose that patient has acromegaly or not?

Normally, growth hormone should be suppressed by giving glucose. Suppression of GH by giving glucose excludes acromegaly.

What is the treatment for acromegaly?

Pegvisomant - GH receptor antagonist.
Transsphenoidal removal of pituitary tumor.

Study group discussion: HSV encephalitis and musical hallucinations

Fun fact: HSV encephalitis is associated with musical hallucinations.

It's due to disruption of connections between the sensory cortex and reticular formation.

Is that specific for HSV only? Like the way auditory hallucinations is characteristic of schizophrenia?

No, it occurs in epilepsy, intoxication and other focal brain lesions as well.

I've heard that musical hallucinations occurs in people who listen to music for long periods of time. Not sure if it's true.

JVP in pericardial tamponade

Greetings everyone!

Today, I was reading about JVP in pericardial tamponade. I started explaining a few concepts to myself and then I thought maybe everyone would like to know about this! So I wrote them down for you guys to read.

Why is y descent absent in JVP in pericardial tamponade? 
Y wave is due to ventricular relaxation. The ventricles can't relax when the pericardium is full of fluid, leading to the absence of y descent.

JVP in pericardial tamponade

Why is there a prominent x descent in JVP of pericardial tamponade?

Pharmacological agents that relax lower esophageal sphincter mnemonic

Pharmacological agents that relax lower esophageal sphincter mnemonic

ABCDEF MINTS

Alcohol
Anticholinergics like Atropine
Barbiturates
Benzodiazepines like Diazepam
Caffeine or coffee
Chocolate (My favorite!)
Dopamine
E (Prostaglandin E1 & E2)
Fat
Meperidine
Nitrates
Theophylline
Smoking
Peppermint (mints)

That's all!
-IkaN

Cirrhosis of liver: Concepts, mechanism and pathophysiology

Hello everyone! 

In this really long post, I'll be discussing the pathophysiology of some of the signs, symptoms and conditions seen in chronic liver failure / alcoholic liver disease. We are going to focus on the WHY.

Let's get started ^__^

Why is gynecomastia, testicular atrophy and female pubic hair distribution seen in males with chronic liver failure?
Physiology:
- Liver metabolizes estrogens.
Pathology:
- In cirrosis, estrogen degradation is decreased, so estrogen concentration are elevated causing testicular atrophy, gynecomastia & changes in pubic hair.
- Estrogen also induces SHBG production and this further reduces the free testosterone levels.

Stigmata of diseases

What does stigmata mean?

Stigmata means some lesion, mostly skin, which is visible, showing the patient is suffering from that particular disease.
In some diseases, like leprosy and tuberculosis, the patient may not want to reveal the condition because of the stigmata associated with the disease in society. But due to certain signs, the disease gets revealed. (These diseases were considered a disgrace in earlier days.)

Examples -