Pneumococcal vaccines mnemonic for the USMLE

Hey!

So we already have a wonderful post written about these vaccines here.

I am just here to share the mnemonic! :)

Mentzer index mnemonic

Hello everyone!

Na-K ATPase and Donnan effect

Hello Awesomites :D

In Previous post, I gave an overview on Gibbs Donnan equilibrium.

This is to clear the doubt that Could animal cells attain Gibbs Donnan equilibrium?

Animal cells could never attain equilibrium. Plasma membrane can't sustain hydrostatic pressure gradient without evolution of some means of avoiding Gibbs-Donnan equilibrium.

Why do we need some new means? Because we couldn't afford to have "Protein free cell or no protein containing cell".

So,
Na-K ATPase counteract Gibbs Donnan equilibration.
The bottom line effect of this is to make cell effectively impermeable to NaCl. Gibbs Donnan equilibrium do not reached and cell does not swell inspite of the presence of protein ion.

Hope you got it.
-Upasana Y. :)

Donnan Effect

Hello Awesomites :D

I was reviewing my 1st year physiology notes then I found this topic.
Let us begin. :D

We know that ions move across the membrane depending on 2 gradients :-
1. Concentration gradient (No. Of ions)
2. Electrical gradient (Charge of ions)

 The net movement of ion  is decided by the Electrochemical gradient.

I will do some calculations below. Caution point is when I will talk about electrical neutrality, I consider charge of ions.

Donnan Effect  ON DISTRIBUTION OF IONS has three effects:-
1. Because of charged proteins in cells, there are more osmotically active particles in cells than outside.
So what does it means? Animal cells do not have cell wall. Osmosis would make them swell and eventually rupture.

How to prevent this?
This implies need for evolution of pump (Na-K ATPase) to maintain osmotic equilibrium between cells and interstitial fluid across cell membrane.

2. At equilibrium the distribution of the permanent ions across the membrane is assymetric, an ELECTRICAL difference exists across the membrane.

What does it means?
K+ moves along its concentration gradient (as it is free to move)  lead to electrical disequilibrium.

This disequilibrium influence K+ to move continuously. Chloride also move it's side to equilibrate with charge.

Eventually ion concentration would stabilise (in diagram 64=64)  and individual solute concentration would not change over time (means 6 Na+ 4 Cl- 10 K+ 3 prot4- inside)
Gibbs Donnan force are responsible for development of a membrane charge due to passive process.

3.Because there are more proteins in plasma than in interstitial fluid,there is Donnan effect on ion movement across the capillary wall.

What do you mean by Donnan equilibrium?

Have a great day.

-Upasana Y. :)

Neuroendocrine tumours of the Stomach

Neuroendocrine tumours of the stomach are uncommon tumours with a benign behaviour usually- hence known commonly as "Carcinoids"

They are diagnosed by the usual histomorphology of small organoid nests or clusters of cells with salt pepper or stippled nuclear chromatin and synaptophysin or chromogranin positivity.

We divide them into 4 types

1. One develops in the background of reactive gastrin secreting cell hyperplasia in cases of pernicious anemia

2. The second type is a part of Zollinger Ellison syndrome

3. The third is independent of any syndromic association or association with pernicious anemia

4. The fourth type is classified based on the histomorphology- "Neuroendocrine Carcinoma"- showing mitosis, nuclear pleomorphism, hyperchromasia

The closest differential could be Gastrc Lymphoma-
1. Lymphomas would not usually have an organoid pattern, tend to grow sparing the crypts and tend to form lymphoepithelial clusters
2. They would not have synaptophysin or chromogranin positivity
3. They would stain for the relevant lymphoid markers according to the cell of their origin- B or T cell type.
4. Hormone or S. Gastrin levels would be useful

House MD - Neurocysticerosis

Well, the post is from Author's diary. So read it when you are free.

Story time.

"Roll no 33, tell me how is Neurocysticerocis formed?" Asked our microbiology professor and ordered me-roll no 34 to be ready with my answer for the same. This happened during my preliminary viva. Microbiology was my last viva. This was my last moment with vivas, after this, awaited the exotic diwali vacations!! ( Rather PLs)

Roll no 33 started answering the question. However, she was wrong. Sir interrupted her and said, "I need the mechanism, not life-cycle! ".

He turned towards me and asked the same.Till this time I was in a delusion that neurocysticerocis is formed because larvae get an access to systemic circulation and end up infecting the brain!!
I was more than wrong! I got a deduction in my marks obviously.

Nevertheless, I was happy with "The End of viva".
Well, I tried to find out the mechanism of neurocysticerocis in my free time but I was not able to find it in any of the books.

So, vivas were over and I was free. I started watching the remaining episodes of "House MD. After coming home, I realized that I forgot to install the remaining episodes of House MD :(

I had season 1, so I preferred re-watching it.
Season 1 - Episode 1 - Pilot.

Guess what!!!!?
I found my viva answer of neurocysticerocis in my favourite series. Dude how can I miss this?!

So House explain's neurocysticerocis as follows:

"In a typical case, if you don't cook pork well enough, you digest live tapeworm larvae. They have  got these little hooks, they grab on your bowel, live,  grow up and reproduce.Tapeworm can produce 20,000-30,000 eggs which go out in excretion but not all of them. Unlike the larvae, eggs can pass through the walls of intestine and enter the circulation. Obviously, blood goes everywhere. As long as, it's healthy, your immune system doesn't even know it’s existence. The worm builds a wall, uses its  secretions to shut down immune system and control fluid flow. It’s really very beautiful. As it dies, this parasite loses it's ability to control the immune system. Immune system wakes up, starts attacking the worm and everything starts swelling up."

After this episode I realized I am a big moron and I haven't watched House MD with my utmost dedication. So, I am
re-watching it now :D

Everybody lies!!

Good - bye!

--Demotional bloke.

Quick Facts - Swimming associated Diseases.

Hello everybody!
Let's swim through microbiology today and review some swimming related diseases.

Swimming pool conjunctivitis -
Caused by : Adenovirus 3,7 and 14 (tends to occur in children's swimming camps)
                      Chlamydia Trachomatis.

Swimming pool Granuloma -
Caused by Mycobacterium Marinum.

Swimmer's Itch -
Caused by Schistosoma Mansoni.

Swimmer's Ear - Pseudomonas.

Swimming in contaminated water can also cause Primary Amoebic Meningoencephalitis by Naegleria Fowleri which is a free living ameba.

If you come across more eponymous swimming diseases do share.

Let's learn Together!
-Medha.

BRCA1 vs BRCA2 gene mutations and associated chromosomes (mnemonic)

BRCA1 gene mutation is located on choromosome 17 while BRCA2 gene mutation is located on chromosome 13, how to remember that?

BRCA2 :
- 1 and 3 in number 13 if joined together, they look like a breast 1+3 =>13
- this reminds me of its association with breast cancer.

BRCA1 is really famous:
-Another Famous mutation is P53 gene mutation which causes LI Fraumeni syndrome.
-Flip IL in LI Fraumeni and you get the number 17.
-Asssociate LI Fraumeni (p53) and  BRCA1 together since both are very famous => both are due to chromosome 17 mutations.

and that's it :)

-Murad

Uses of herbal medications in the US mnemonic

Hello!

These are frequently tested on the USMLEs, so be aware of them :)

Quick Facts - Fried Egg Appearance!

Hello everybody!

So the next time you make your own fried egg add some medicine to it!

Here is a list of certain characteristic fried egg appearances that you may Come across:

Mycoplasma Pneumoniae colonies show fried egg colonies on Eaton agar.

Oligodendroglioma cells show a fried egg appearance.

Hairy cell leukemia cells on bone marrow biopsy.

Seminoma and Dysgerminoma  cells on light microscopy.

Parietal cells of the stomach due to acidophilic cytoplasm & large central nuclei also resemble fried egg appearance.

Plasma cells in MULTIPLE MYELOMA

Malassezia furfur 
They also show fried egg appearance on sabourauds dextrose agar with olive oli overlay.

Let's learn Together!
Medha.

Quick Facts - Human Herpes Virus 6!

Hello everyone!

Here are some quick important facts for the Human herpes Virus 6 (HHV-6)

HHV-6 affects T cells binds to CD46.

It has two variants 6A and 6B

The 6B variant causes 6th disease  (easy to remember HHV-6 causes 6th disease)
also called as Roseola infantum or exanthema subitum in children.

Roseola infantum -The disease is characterized by high grade fever wherein Febrile seizures can be seen.
After the defervescence the Rash classically appears.
One important finding is Nagayama spots which are small reddish papular lesion seen on the soft palate.

In Older age grp causes Infectious Mononucleosis like disease.

If you have more facts on it, Do share!

-Let's Learn Together!
Medha

USMLE Step 3: CCS Inflammatory bowel disease checklist

These are just my notes / checklist from the UW case 3. This post will not make sense to you if you are not preparing for CCS.

How to remember Sulfasalazine is associated with low sperm count

Hello!

I keep forgetting that sulfasalzine is the IBD drug associated with oligospermia... Sooo mnemonic.