Posts Tagged ‘cancer’

SIRT4 a potential new important cancer drug target

// July 27th, 2013 // No Comments » // Medical Science

Marcia Haigis, HMS associate professor of cell biology, led a team that has uncovered SIRT4 as an important player in the DNA damage response pathway.  Here’s an article I haphazardly discovered today on an important sirtuin protein called SIRT4. Harvardianites have discovered that when SIRT4 is absent from mice, the cell cycle doesn’t function to arrest cell division and keep the cell from becoming malignant/cancerous. SIRT4 acts as a physiological weigh-station to prevent the cell from proceeding when there’s a stressed, cancer-producing environment (such as with excessive UV rays) that could lead to cancer. What does this mean? It means that drug discovery could have room for a new target that could lead to some important therapies. I’m interested in it. During undergrad I did undergraduate research in drug discovery and got a sense of what goes into figuring all of these systems out. I appreciate this research greatly.

Here’s the link to the article: http://hms.harvard.edu/news/cancer-checkpoint-4-4-13

Tell them Isaac sent you.

Math Meets Medical Science – Additive Emetogenic Potential

// May 19th, 2012 // No Comments » // Medical Science

I was just playing around with some numbers one day after a lecture for school and came up with some formula for calculating the additive emetic level of more than one antineoplastic drug. I thought I’d share it here in case anyone thought it was interesting (and, well, there’s little else to share). Maybe someone’s doing a Google search and would think this is cool like I did… (I didn’t know what else to do with this since I never got a chance to use it for the exam :-/ Garrrr…)

Antineoplastics are categorized according to their emetogenic potential, Frequency of emesis
▫ Level 1 (<10%), Busulfan, Vincristine, Chlorambucil
▫ Level 2 (10-30%), Gemcitabine, Paclitaxel, Asparaginase
▫ Level 3 (30-60%), Cyclophosphamide, Methotrexate
▫ Level 4 (60-90%), Carmustine, Cisplatin, Irinotecan
▫ Level 5 (>90%), Mechlorethamine, Dacarbazine
Combining antineoplastics may increase emetogenic risk:
For example:
(1) 2 + 2 + 2 = 3
(2) 2 + 2 + 3 = 4
(3) 3 + 3 + 3 = 5
If you have 3 drugs that give about a Level 2 Emesis (10-30%), the aggregate that the patient would experience would be 30-60% (More Emetogenic)

If you’re given a list of drugs and need to find the additive emesis level for that list based on the level of each drug:
Let a = Minimum Range Number for a given drug’s Level number
Let b = Maximum Range Number for a given drug’s Level number
Let m = The percentage of emesis for a given drug (1 singular drug).
Let n = The number of drugs in the list given (if 1 drug, n=1; if 2 drugs, n=2, etc.)
Let p = The sum of the percentages for a number of drugs (many drugs)

Formula #1: m = (b/2)
— For a given drug “n” Formula #2: p = sum(m) + 1
— Letter j represents Then, answer = the level of p.

2 + 2 + 2 = 3 – There are three Level 2 drugs given.
Therefore, n=3.
– Level 2’s Range is 10-30%.
Therefore, a = 10, b = 30
– m1 = (30/2) = 15%
– m2 = (30/2) = 15%
– m3 = (30/2) = 15%
– p = sum(15% + 15% + 15%) + 1 = 46%
The answer is “3” since 46% is in the Level 3 range

2 + 2 + 3 = 4 – There are two Level 2 drugs and one Level 3 drug given.
Therefore, n = 3.
– Level 2’s Range is 10-30%.
– Level 3’s Range is 30-60%.
– m1 = (30/2) = 15%
– m2 = (30/2) = 15%
– m3 = (60/2) = 30%
– p = sum(15% + 15% + 30%) + 1 = 61%
The answer is “4” since 61% is in the Level 4 range.

3 + 3 + 3 = 5 – There are three Level 3 drugs and one Level 3 drug given.
Therefore, n = 3. – Level 3’s Range is 30-60%.
– m1 = (60/2) = 30%
– m2 = (60/2) = 30%
– m3 = (60/2) = 30%
– p = sum(30% + 30% + 30%) + 1 = 91%
The answer is “5” since 91% is in the Level 5 range.

Hope that amuses someone out there. -ID