Monday, January 23, 2012

Totally drug resistant TB


One of the biggest problems in Tuberculosis (TB) therapy nowadays is that patients have to take antibiotics for up to 9 months. As many patients feel better before this time, they prematurely stop their treatment, leaving pools of the most drug-resistant M. tuberculosis in their lungs. This contributes to the emergence of complete drug resistance in future patients.
In the past few years, strains of drug resistant Mtb have become prevalent. In fact, resistance is so wide spread that it is now being classified as multi-drug resistant (MDR-TB) and extreme-drug resistant (XDR-TB). Two of the world’s most populous countries, India and China, account for more than 50% of the world’s MDR-TB cases.
Recent reports have also confirmed a new strain of existing Mtb which is completely untreatable and has been designated as Totally drug resistance TB (TDR-TB). Indeed, strains of Mtb have even evolved resistance to all major available anti-TB drugs. India (2012) is the third country in which a total drug-resistant form of the TB has emerged, following cases documented in Italy in 2007 and Iran in 2009. There is a need for a more readily available treatment that is effective against both sensitive and drug-resistant strains of M. tuberculosis is evident.

Sunday, January 22, 2012

Nano reactions


Recently, nanoporous materials have emerged as important and efficient heterogeneous catalysts for the organic transformations owing to their excellent textural characteristics including high surface area, large pore volume, and uniform pore size distribution, and its simplicity in workup and recyclability. The pore diameters are chosen to control the access of molecules to the catalytic reaction sites located inside the porous cavities. Only the molecules of certain sizes and chemical properties are selected and guided to the reaction centers where they are efficiently transformed to the desired products.

Friday, January 20, 2012

What's a PhD worth?

Here's another article in the nature that makes some good points about the worth of PhD.

"The number of science doctorates earned each year grew by nearly 40% between 1998 and 2008, to some 34,000, in countries that are members of the Organisation for Economic Co-operation and Development (OECD). The growth shows no sign of slowing: most countries are building up their higher-education systems because they see educated workers as a key to economic growth. But in much of the world, science PhD graduates may never get a chance to take full advantage of their qualifications"

PhD program use to be for science-loving driven people and the world want more innovation from academic science to solve the problems.

Tuesday, January 10, 2012

Mycobacteria and the great wall

Mycobcaterial cell wall is unique, thick waxy and hydrophobic in nature, which ensures its survival inside human macrophages by resisting oxidative damages.The waxy, highly impermeable nature of the wall provides the required defense mechanism against antibiotic agents, and the host organisms. A key component of the cell wall is mycolic acids. Mycolic acid  accounts up to 60% of the dry weight of the organisms which means that most percentage of mycobacteria is a cell wall.  Thorough understanding of the influence of polarity on the drug penetration in to highly impermeable mycobacterial cell wall will guide us to improve permeability.

The permeation ability of a lipophilic molecule is inversely related to the fluidity of the cell wall, which decreases as the length of fatty acids in the mycolic acids layer increases. The permeability barrier presented by this cell envelope is also thought to be a reason why many common antibiotics are ineffective against mycobacteria. Lipophilic drugs, such as fluoroquinolones or rifamycins, pass more easily through the lipid-rich cell wall and thus are more active.
It is clear that, depending on the library screens towards compounds with a particular physicochemical parameter could actually be detrimental and decrease the diversity of finding new anti-TB drugs.