Study group discussion: Serial interval and communicable period

What is the difference bw serial interval and communicable period?

Communicable period is the one in which the disease is transmitted from one case to another. (Also known as infectivity.)
The patient might have the disease but may not be infectious because of latent phase.

Serial interval is the time period in which the disease manifests from one case to another.

It's different from communicable period because the disease doesn't manifest immediately, so the case might present to you late.

Serial interval = Latent period + communicable period (Roughly)

Study group discussion: Temporal arteritis

A 60 year old male presents with headache, scalp tenderness, painful temples, pain on chewing & visual disturbances.. Diagnosis?

Answer: Temporal arteritis

What tests you would do to confirm the diagnosis?

Answer: Raised ESR, temporal artery biopsy

Treatment?

Answer: High dose steroids like prednisolone!

Temporal artery branch of?

Answer: ECA, the external carotid artery!

Study group experience #15

Structures that pass through the diaphragm mnemonic
Purtscher's retinopathy

Biliverdin
Largest protein and the smallest protein in the human body

Hemolytic disease of new born
Evening rise of temperature in tuberculosis and malaria
Causes of edema

Chloroquine and Behcets disease
Drugs contraindicated in myasthenia gravis
Drugs used in the treatment of Alzheimers disease

Smoking and hernia
Eponymous terms in hernia and mnemonics

Correct order of clinical assessment of the abdomen

More information on the study group

It's amazing studying with you guys, I wish I could update - discuss more often, but internship is really draining me. Trying my best to catch up. Love you all! :)

-IkaN

Study group discussion: Correct order of clinical assessment of the abdomen

Question: During clinical examination of abdomen what is the correct sequence of the following events?
Palpation - inspection - auscultation - percussion.

Answer: You first need to auscultate in abdominal examinations because bowel sounds increase after palpation. So it would be inspection -  auscultation -  palpation - percussion.

When assessing most body systems, the appropriate order is inspection, palpation, percussion, and auscultation. However, with the abdominal assessment, auscultate before you manipulate the abdomen with palpation and percussion. The rationale for this is that manipulation of the abdomen with palpation and percussion may stimulate peristalsis and thereby alter your examination findings. So the appropriate order for the abdominal examination is inspection, then auscultation, followed by palpation and percussion.

Research paper: http://www.ncbi.nlm.nih.gov/books/NBK420/

Extra tips: You wanna ask the patient whether it hurts somewhere and palpate that area last.

While examining abdomen always expose the patient from nipples to midthigh. Also one more important thing is that, abdominal examination is never complete without examination of external genitalia.

Organ of Zuckerkandl.

There are several extradrenal sites where pheochromocytoma occurs, and this, the 'organ of Zuckerkandl' is one interesting site.

It actually is a cluster of bodies,located either at the bifurcation of the abdominal aorta or at the origin of the inferior mesentric artery and they contain chromaffin cells derived from the neural crest.

These are also known as 'paraortic bodies' but differ from 'corpora aortica'(also a chromaffin body)which lies near to the thoracic aorta.

The organ of Zuckerkandl is said to be responsible for secreting catecholamines and other vasoactive substances. It has a function of supplying catecholamines to the fetus especially in the first trimester of pregnancy and regresses usually in the third trimester.



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Study group discussion: Largest protein and the smallest protein in the human body

How many amino acids make up a protein ?

>100 ~ proteins
10-100 ~ polypeptide
<10 ~ peptide

Which protein is smallest in the human body?

Thyroid releasing hormone or TRH should be the smallest protein in the human body, with 234 amino acids. (> 100 amino acids is a protein.)

Smallest polypeptide in the human body should be insulin, with 54 amino acids. (10-100 amino acids is a polypeptide.)

Smallest peptide in the human body should be glutathione, with 3 amino acids. (<10 amino acids is a peptide.)

I concluded these on what I found on Google. Correct me if I'm wrong.

Largest protein is titin in the human body!

Interesting virology fact:-
The largest viruses as Poxviruses measuring 300nm are as large as the smallest bacteria (mycoplasma). The smallest viruses as Parvovirus measuring about 20nm are nearly as small as one of the largest protein molecule, hemocyanin.

Study group discussion: Hemolytic disease of new born

What is immunogenic hemolytic disease of new born?

Answer: In immunogenic type, the immune system plays a role in the pathogenesis of the disease. Rh incompatibility is an example.

What are the causes of non-immunogenic erythroblastosis fetalis?

Answer: Examples of non immunogenic erythroblastosis fetalis are iron deficiency anemia, CMV infection in mother, etc.

Can congenital hemolytic anemia be a cause of non-immunogenic erythroblastosis fetalis?

Answer: Yes.
Though usually, hemolytic anemias don't present till later in life (Mostly because of HbF).
Exceptions would be severe alpha thalassemia in which all 4 alpha chain synthesis is deleted. 4 gamma chains combine, leading to the formation of HbH (Bart's hemoglobin!) They die in utero due to severe hypoxia and hydrops.

Study group discussion: Drugs used in the treatment of Alzheimers disease

Can anyone help me with pharmacological classification of anti Alzheimer's agents?

For Alzheimers, cholinesterase inhibitors.. And a drug called memantine.

NMDA receptor antagonists.

Drugs: Tacrine (tetrahydroaminoacridine), donepezil, rivastigmine and galantamine.
Mechanism: Inhibition of cholinesterase, with a resulting increase in cerebral levels of acetylcholine.

Antioxidants, selegiline, tocopherol (vitamin E), estrogen replacement in females, Ginkgo Biloba extracts are other drugs which may benefit in Alzheimers disease.

Study group discussion: Eponymous terms in hernia and mnemonics

Here's a list of eponymous hernia terms I was sent. I added a few mnemonics to where I could. Others you'll have to memorize!

Gibbon's hernia- Hernia with hydrocoele

Berger's hernia - Hernia in Pouch of Douglas
Mnemonic: Burgers are made of dough.

Grynfelt's hernia - Upper lumbar triangle hernia.

Petit's hernia - Lower lumbar triangle hernia

Cloquet's hernia- Hernia through pectineal fascia
Mnemonic: The hernia is cloaked, peccantly.

Narath's hernia - Behind femoral artery

Hesselbach's hernia - Lateral to femoral artery
Mnemonic: hesseLBAch - Lateral to big artery.

Serofini's hernia - Behind femoral vessels
Mnemonic: SeroFini - Supported by femoral vessels.

Laugier's hernia - Through lacunar ligament
L for Laugier's, L for Lacunar

Tealse's hernia - In front of femoral vessels

Richter's hernia - Part of circumference of bowel wall is gangrenous
Mnemonic: Richie rich has a large circumference pocket of money.
Alternatively, riChter Circumference.

Littre's hernia - Hernia with Meckels's Diverticulum
Mnemonic: Meckels is a congenital defect, found in Little babies.

Sliding hernia - Posterior wall of sac is formed by colon or bladder

Maydl's hernia - 'w' hernia
Mnemonic: M upside down is W.
Phantom hernia - Localised muscle buldge following muscular paralysis
Mnemonic: Phantom for Phantom, P for Paralysis

Spigelian hernia - Through spegelian fascia

Obturator hernia - Through obturator foramen

Femoral hernia - Hernia medial to femoral vein

Beclard's hernia - Femoral hernia through saphenous opening

Study group discussion: Biliverdin

Why biliverdin is reduced to bilirubin? It isn't toxic, it is water soluble.. Then why convert it to bilirubin?

According to some, biliverdin works just fine. Mammals have evolved the energetically expensive, potentially harmful and apparently unnecessary capacity to reduce biliverdin.

According to others, the conversion is not a wasteful process. Bilirubin is a cytoprotectant and that's why biliverdin is converted into bilirubin. It's also a physiological anti oxidant!

Source: http://m.pnas.org/content/99/25/16093.full

About me!

Hello there awesomites! Feels great to write this for Medicowesome :-)

Where to start? Well, I am a total  astrophysics geek. Anything -spacetime,dark energy, black holes, wormholes catches my fancy.That type of guy who loves staring at the starry sky. Just finds amazing how the tiny word 'universe' encompasses the massive expanse lying out there. Loves going to the point where physics meets philosophy.

Likes looking into nothing, thinking and imagining.

House MD fan. Sherlocked.
Christopher Nolan worshipper. Interstellar fanatic.

I have a thing for rare, fancy medical syndromes! Dreams include running a diagnostics department like House. :-p

Talking of music,a Linkin Park fan, like the regular Bollywood music too.

Proud of India and its rich heritage.

Hobbies include driving cars, riding bikes and even bicycling. Gaming included.

Finally, an animal lover,dreamer and a bit of foodie..

-Sushrut



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Heme synthesis mnemonic

Hey everyone! Long time no see!

Today we'll be learning about heme synthesis.

The biosynthesis of heme mnemonic 

Study group discussion: Temporal arteritis

A 60 year old male presents with headache, scalp tenderness, painful temples, pain on chewing & visual disturbances.. Diagnosis?

Answer: Temporal arteritis

What tests you would do to confirm the diagnosis?

Answer: Raised ESR, temporal artery biopsy

Treatment?

Answer: High dose steroids like prednisolone!

Temporal artery branch of?

Answer: ECA, the external carotid artery!

Study group discussion: Causes of edema

Today, we'll be talking about causes of edema.

Causes of Edema can be inflammatory and noninflammatory!

Noninflammatory causes:
1) Increased hydrostatic pressure
2) Hypoproteinaema
3) Lymphatic obstruction
4) Sodium retention

Inflammatory causes:
1) Acute inflammation
2) Chronic inflammation
3) Angiogenesis

Here is a mnemonic shared by an awesomite: HILARI IS SAVE (Hilary)
Heart failure
Iatrogenic
Liver causes
Aldosterone increased/ ADH increased
Renal cause
Inadequate protein in blood (hypoalbuminaemia)

Causes for the inadequate protein in blood are:
Intake Inadequate (Kwashiorkor)
Secretion fro pancreas decreased (pancreatitis)
Synthesis decreased (liver failure)
Absorption decreased (Crohn's disease)
Vomit (pyloric stenosis)
Excretion increased (nephrotic)

I remember this in Conrad Fischer's tone, "Cirrhotic, Nephrotic and CHF. Cirrhotic, Nephrotic and CHF!" though.

That's all!

-IkaN

Study group discussion: Drugs contraindicated in myasthenia gravis

Hey everyone!

Today's topic is about drugs that are contraindicated in myasthenia.

Can you guess them all?

Drug a. Myasthenic woman with eclampsia develops ptosis

Drug b. Patient with hepatitis C develops respiratory depression

Drug c. Filmstar drug

Drug d. Wilson's disease

Answers:
a. MgSO4
b. Interferon
c. Botox
d. Penicillamine

Random fact:
The actor, Amitabh Bachchan has interferon induced myasthenia gravis which was used to cure his hepatitis C infection. And because of that he can't use botox.. Hence, his skin looks so wrinkled compared to other film stars of his age. Hence, two important drugs causing myasthenia and who worsen it are interferon and botox.

More information on study group

Here is some more information, since people have been asking!

How do I join?

Click here!

Can I view the group discussions without being on the group?

Yes! View the Study group index. All topics discussed may or may not be posted on the blog, do to time limitation, of course.

Study group discussion: Evening rise of temperature in tuberculosis and malaria

Why is there an evening rise of body temperature in tuberculosis?

Answer: Because endogenous corticosteroid have their levels low in the evening. Cortisol bursts are least frequent in the evening. And steroids are anti-inflammatory!

Why not in all infections? What's special about tuberculosis?
We don't know the answer to this question. If you do, please tell us!

This answer was submitted to us by an awesomite: Increased Cortisol Cortisone Ratio in Acute Pulmonary Tuberculosis: Recent research works regarding TB has revealed that there is increased cortisol level in TB.
Cortisol & IL-1 interaction: At high level cortisol has negative feedback effect on IL-1.
Conclusion: In TB, cytokines, specifically, IL-1 level is markedly increase that leads to fever, but as cortisol level is also high than normal it counteract the action of IL-1 & as a result fever remains low grade.
Due to exaggerated diurnal variation,cortisol effect is very high in late night while very less in evening onwards that leads to evening rise of temperature & night sweating. Normal diurnal variation of body temperature also play a role to make this change more prominent.
Source: http://www.doctorshangout.com/m/blogpost?id=2002836%3ABlogPost%3A423964

Even malarial paroxysms occur in the evening, don't they?

Answer: Yep. Malarial paroxysms have a different reasons. Steroids ain't responsible.

What's the reason for malarial paroxysms then?

Answer: It depends when the entire cycle of trophozoites burst from RBC's.

Here's from one of the members personal experience:
I have had malaria.. I had paroxysms at late night.

Study group discussion: Smoking and hernia

I have a doubt .. Today in surgery ward, my professor asked me how does smoking directly cause hernia! :/

I know the indirect cause! Coughing!

By weakening collagen?

Does smoking affect collagen synthesis or metabolism? At which step does smoking affect collagen?

It causes less production!
The synthesis of subcutaneous collagen in smokers is specifically impeded, indicating an impaired wound-healing process. Because mature collagen is the main determinator of strength of an operative wound, the results support the view that patients should be advised to stop smoking before an operation.
Source: http://www.ncbi.nlm.nih.gov/pubmed/9551072

In conclusion, smoking is an important risk factor for recurrence of groin hernia, presumably due to an abnormal connective tissue metabolism in smokers.
Source: http://www.ncbi.nlm.nih.gov/pubmed/11910469

Oh....ok. Thanks!

Autonomic system drugs mnemonic

Please give some tips on remembering cholinergic and adrenergic drugs.

- ine are beta agonists
(Terbutaline, ritrodine)

Drugs ending in

-sin are alpha antagonists 

(Prazosin, terazosin)

- olol are beta blockers

(Propanolol, metoprolol)

- alol are alpha + beta blockers (Labetalol)

- stigmine are cholinergic drugs
(Neostigmine, physiostigmine)

Alice in Wonderland syndrome

Came across this interesting syndrome a few days back. Described by Dr. John Todd 1955, it is also known as Todd's syndrome or lilliputian syndrome. The causative factors involved are usually migraines, tumors or hallucinogens. Epstein Barr virus is also thought to be associated with it.

Study group discussion: Structures that pass through the diaphragm mnemonic

When we go to thorax or abdomen... It's hard to remember their relation... Are there any tips?

What sort of relation? The relation of structures that pass through the diaphragm?

Yep.

Ok I know one mnemonic for that.

I ate (8) ten eggs at twelve.

I: Inferior vena cava
aTe: T8!
Eggs: Esophagus (Vagus rhymes with it!)
Ten: T10
AT: Azygous vein, Thoracic duct! Twelve: T12

So to summarize:
IVC - T8
Esophagus, vagus - T10
Azygous, thoracic duct - T12

Hope this helps!