Standard Cellular Signaling Pathway

Standard Cellular Signaling Pathway

Wednesday, August 1, 2007

The NK Linked Lecture Series: Nobel Laureate Richard Roberts

Nobel laureate Richard Roberts begins the lecture by advocating open-source publishing, where the content of a journal is made freely available on the internet by a website such as PubMed Central. He then goes to speak about restriction enzymes.

Enjoy.

Tuesday, July 31, 2007

Prions

Zombies at the Molecular Level

We've seen the cheesy zombie films. Mindless living dead creatures with the only goal to harass the living, often with the intent to dine on their brains. Where the newly and unfortunately lobotomized victims soon after also become zombies with the same insatiable platelet. Soon after everyone in town is transformed.

As incredulous as this sounds, a story along these lines is a plausible threat and a cause for much concern. Although the gravity of the situation is great, the scale at which these mutants operate is minuscule. I refer to the "mutated" proteins known to as prions.

Prions arise from endogenous proteins (referred to as PrPc) found in brain tissue, its native function has not been fully elucidated. The functional PrPc can undergo a conformational change (the exact mechanism is also not fully elcudiated) altering it to the infectious prion state (dubbed PrPSc). The conformational change is initiated by contact of PrPSc with PrPc. The basic reaction scheme is listed below.

PrPc + PrPSc → 2PrPSc

Just one inital infectious protein, PrPSc, could be enough to transform all native PrPc. While the main transformation method requires PrPSc, it is not fully understood how the first PrPSc is formed; the twist on the chicken or egg conundrum. Although there is evidence showing that cows that have ingested the brain matter of diseased cattle will also contract the disease, the question on how the formation of the inital PrPSc occurred is still unanswered.

If the conformation into the PrPSc form resulted in a minimal behavioral difference from PrPc, there probably would be little cause for concern. Unfortunately, this conformational change coincides with drastic functional changes, reinforcing a main staple of biochemistry that "form equals function".

Once formed, PrPSc begins to congregate extracellularly, forming amyloid plaques that will ultimately disrupt the normal function of the tissue. Amyloid plaque formulation results in transmissilbe spongiform encephalopathies (TSE), a lethal condition. The most notable disease caused by prions is "mad cow disease" due to past media attention. In humans, prions have been associated with Creutzfeldt-Jakob disease, Gerstmann-Straussler-Schninker syndrome, Fatal familial insomnia, sporadic fatal insomnia, Alpers syndrome and Kuru.


Monday, July 30, 2007

The NK Linked Lecture: DNA and the Brain

A lecture given by Dr. James Watson that was made possible by Authors@Google series. Dr. Watson comments on his role in the discovery of the DNA double helix and reports on some of the research being conducted at Cold Springs Harbor, of which he is The Chancellor (I assume this position is equivalent to the director).

Most notable quote of the lecture:
" This century will see the coming together of psychology and biology in the way that the last century was the coming together of chemistry and biology."

Dr. Watson's lecture focuses on the genetic roots of autism. Autism being a neurological disorder, which the disease manifests via spectrum as opposed to "present/not present".
Looking for phenotypic patterns present in the progenitors of autistic children, Dr. Watson comments on research where subjective mental state assessments have been gathered for autistic progenitors and then compared to the prevalence of autistic child births between these individuals. An example being that the average IQ for autistic progenitors is 112, when the over-all average is 100.

Here's where it gets tricky though. Another researcher, Simon Baron-Cohen, came up with the categories of the female mind and male mind (Which in my opinion is a very poor choice of names for these categories). Where the male mind is defined as a systemizer, an individual that is mathematics based, logical and the female mind is defined as an empathizer, an individual that is good at connecting with other individuals. I believe that the terms male and female mind need to go; just use empathizer and systemizer instead. This choice of nomenclature will just inhibit these findings by miring them in unnecessary politically correct battles. Aside from the poor nomenclature, Dr. Watson states, that two individuals who are assessed as systemizers (male-mind oriented) are more likely to have an autistic child.

This appears to make sense, that individuals with a phenotype to systemize as opposed to empathizing will produce offspring more prone to systemizing, assuming that empathizer-systemizer spectrum holds true. But what genetic or neurological reasons are there for these parameters to be mutually exclusive? I believe that I have encountered many people who I would categorize as both strong systemizers and empathizers. Furthermore, according to this theory, that autism can be described as an individual at the extreme systemizer end of the empathizer-systemizer spectrum,then there should also be examples of neurological disorders on the opposite end of this spectrum.

Although I found this lecture engaging, I believe that I need to read more of Baron-Cohen's research to fully understand his position.

Well, enjoy the presentation.


Friday, June 29, 2007

A New Addition to Scientific American

The July 2007 copy of Scientific American boasts a new and unique section entitled Updates. This new section offers a brief follow up on some of the big breakthrough stories of previous issues. This is a neat way to keep the public informed about how a novel discovery develops over time and what can happen to it. The editor stated that it will also help to decrease public jadedness over an apparent lack of follow-through; that a major discovery has been announced but yet the status quo is maintained, e.i., no flying cars.

This column will help remind the public that scientific discoveries do not just get lost on the book shelf but are part of an ongoing narrative.

Check it out!

An Internal View of Cellular Processes

An excellent cgi video put together by Biovisions of Harvard University.



The following video contains a commentary about what is going on in the video.



Inner Life of the Cell animation conception and scientific content by Alain Viel and Robert A. Lue. Animation by John Liebler/XVIVO. Here is a link to their website: http://multimedia.mcb.harvard.edu/

Tuesday, April 3, 2007

Simple as Hitching a Trailer

At a molecular level, nature loves multiplicity. Why use one link when you could use a few million. When we, as a species, manufacture something we tend to employ a single component. Galvanized steel, reinforced ceramics and the like are often the bread and butter of engineers. Nature, on the other hand, uses whats been most readily available, namely organic molecules. On the whole, it is easier to break something organic (a piece of wood) as opposed to something inorganic (a piece of steel). Nature has compensated for this deficiency by just upping the amount of organic compounds involved in the bond. It is analogous to hitching a trailer to a truck by the use of innumerable twisty-ties.

It is multiplicity that allows for the astounding height of the redwoods and the hardness of the rhino's horn. So why you might scoff at using twisty-ties in place of a hitch, remember that nature has had great success at holding things together with weak components. On that note, I'm off to hitch a trailer.

Saturday, March 31, 2007

On The Nature of Grad School

As I prepare to enter grad school, I've been pondering on the nature of the beast that I will soon be jumping into.

I believe that the purpose of graduate study (at least for the science Ph.D.s) is to move the individual from a "student" to a "fully functional independent researcher". That when you get your diploma, you should be able to start your career later that hour. Granted there might be a training period where you will get up to speed on current literature (especially in industry), but other than that you are ready to go.

I think that this is applicable to students pursuing a career in either academia or industry.

Although there are often no formal classes required after a few years, students will still be learning as much as if they were. If your research delves into the depth of some topic that you are unfamiliar with, you are going to have to master it to be able to persevere. Signifying a move from class-oriented learning to self-oriented learning.