Tones of Pictures, Most Commons and Mnemonics

Tuesday, July 31, 2007

The Central Dogma Of Molecular Biology

I found these very simple and usefull slideshow for the central dogma.

Ataxia Telangiectasia

Ataxia Telangiectasia------>IgA deficiency

1.cereberal ataxia(narrow-based gate)
3.risk of sinopulmonary infections
Defect in the DNA break repair gene ATM (Ataxia Telangiectasia Mutant).
IgA deficiency-infections of the upper and lower airways.

ATM gene encodes a kinase essential for p53 activity. ATM is inactivated in ataxia telangiectasia-->hypersensitivity to x-rays and predisposition to lymphomas.

amiNo aCids are linked NH2(shorter) to COOH(longer)

Wednesday, July 25, 2007

Petechiae and Ecchymoses

The former is petechiae-small size(pinpoint areas).
The latter is ecchymoses-bigger size.

In few days after that post I had a question from the question bank and according to them, the differences between petechiae, purpurae and ecchymoses are based on their size. For some reason I taught that both petechiae and ecchymoses are some kind of purpura, because of their color. Too busy to check that facts. May be later on, and also I trust usmleworld, these guys really rock.
Yes, I did quick check. That is right.
1.petechiae-less than 0.5 cm
2.purpurae-from 0.5 to 1 cm
3.ecchymoses-more than 1 cm
So, on the first picture there is a combination of petechiae and purpurae.

Bitot's spot

Vitamin A deficiency-->Bitot's spot
Some more pictures:

Monday, July 23, 2007

Thiamine and Beriberi

Dry beri-beri-->Demyelization. Wet Beri-Beri (2B)-->Bi-ventricular failure

Monday, July 16, 2007

Perifollicular hemorrhage and Ring sideroblasts

Goljan the Great made this association between this two completely different findings, based on the form of a "ring". The only thing I can do is just put them into pictures.

A little bit more for the perifollicular hemorrhage:

Saturday, July 14, 2007

To be honest I totally forgot about Telomerase and Retrotransposons. So, humans also have reverse transcriptases.

DNA replication

I know that when you read DNA replication is pretty clear, but the next animation will be very helpful, I guess.


1. dna A protein is the 1st one binding to DNA in the beginning of the replication
2. uRacil-->RNA
3. HELIX=SPIRAL-->Helicase is an enzyme that breaks the Hydrogen bonds, holding the double stranded Helical=Spiral DNA together. Nucleases break PDE bonds
4. DNA polymerase III starts form the 3’ exit of the RNA primer. Polymerization is always from the 3’ exit, but in 5'-->3’ direction

Wednesday, July 11, 2007

Pitting edema

Hypotonic fluid disorders: hyponatriemia; cells swelling
1.hypertonic lost-loop diuretics, Addison's
2.pure water gain-SIADH secretion
3.hypotonic salt gain-right sided heart failure, cirrhosis,nephrotic syndrom
This link explains very well the pathophysiology of the edema:

Wednesday, July 04, 2007

Hepatitis C

Very interesting video for Hepatitis C.