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Cell Division Reversed for the First Time
SubtleGuest writes "Gary J. Gorbsky, Ph.D., a scientist with the Oklahoma Medical Research Foundation, has found a way to reverse the process of cell division.
The discovery could have important implications for the treatment of cancer, birth defects and numerous other diseases and disorders. Gorbsky's findings appear in the April 13 issue of the journal Nature.
"No one has gotten the cell cycle to go backwards before now," said Gorbsky. "This shows that certain events in the cell cycle that have long been assumed irreversible may, in fact, be reversible."
In the lab, Gorbsky and his OMRF colleagues were able to control the protein responsible for the division process, interrupt and reverse the event, sending duplicate chromosomes back to the center of the original cell, an event once thought impossible.
Here is a video of it happening."
From the article "Time-lapse phasecontrast and fluorescence images were collected from cells grown on glass coverslips using a Zeiss Axiovert 200M microscope equipped with a Hamamatsu ORCA camera." They use a fancy (and expensive) inverted light microscope with a digital camera attached to it to take the images. The section on the right part of the movie is made using with a fluorescence stain as the cell proceeds through mitosis. There is a light source attached to the microscope that emits light at a certain wavelength to excite the fluorescence stain that can be bound to a variety of things - mitochondria, DNA, etc. In this case the fluorescence is bound to alpha-tubulin-GFP. Alpha-tubulin is a protein found in microtubules which are involved with cell shape and cell structure. GFP merely means "Green Fluorescent Protein" - that it will fluoresce in the green wavelength. http://microscope.olympus.com/contentsDB/01world/0 1reseach/a_appli/12/contents.html
Use of fluorescence in biochem is really fascinating, and fortunately I have a good amount of experience as a student using fluorescence as a tool. You can bind several fluorescence probes to a cell and get some really cool images:
http://probes.invitrogen.com/servlets/photo?fileid =g002761&company=probes
I can't say whether or not you have ADHD, but I'd just like to correct a misconception that ADHD just implies a lack of attention. The name is a misnomer. ADHD is really about a lack of ability to control attention. An ADHD person will sometimes hyper focus to the exclusion of everything and sometimes have no ability to feel comfortable continuing to do anything for very long. Obviously, everyone falls somewhere on that sort of scale. It's just when someone hits those extremes too often that it is a problem.
Cow Cube
The ability to return a cell to metaphase upon the removal of a chemical (Flavopiridol) which causes the mitotic exit of cells which are expressing non-degredatable Cyclin B is interesting, but it definetly tells us nothing about how to reverse this process in non-transformed human cells. The press release is a bit too effusive about the potential of this finding to radically transform the treatment of cancer, etc. as the finding primarily recomfirms the hypothesis that the degredation of cyclin B is what gives directionality to the cell process, and by blocking the degredation of Cyclin B, you can reverse the cell cycle.
And just in case you're confused like the submitter, there's way more than one protein involved in the cell division process in any eukaryotic cell; Cyclins like Cyclin B are very important, but it's a whole host of proteins that are involved in ushering the cell from G1 to S to G2 to M; assuring alignment, proper exit, arrest upon damage, etc. [One could even argue that the whole point of most cells is to divide, and so every bit of the cell is important and/or participates in some way in the process...]
http://www.donarmstrong.com
This paper said in the summary that this process leads to "realignment of chromosomes at themetaphase plate." So, they do not merge back into one.
What the scientists were mostly concerned with is the fact that this supported the theory that a particular protein directed cell division, at least during a certain phase. The partial reversal of mitosis was just an interesting side effect. The medical and other biological research interest comes in place because now that we have identified this protein and proven that it is indeed the one that regulates mitosis, we can prevent further mitosis by the use of an inhibitor chemical. While this may seem to be a possible cure for cancer, such a discovery would be extremely difficult to put into practice as a pill you take or shot you take. This inhibitor would likely suspend mitosis of ALL cells, breaking down the functioning of many biological processes. Unless a compound is found that preferentially affects cancer cells, which may be possible due to the high division rate in some forms of cancer. This would have little to no effect on cancers caused by a failure in apoptosis. Then again "Cancer" is just a blanket term for a large number of different disorders in which a group of cells grows and divides without control, causing detriment to the rest of the body. Making cancer study mroe difficult is that it often takes failures in several different control systems for a cell to become carcinogenic, as there is a fair bit of redundancy built into these sytems. A "predisposition" to a certain type of cancer often means that one of the inherited genes controlling one arm of the control system is already flawed, so less somatic mutations are required before carcinogenesis. Inherited failure in too many of the control pathways would probably result in termination or developmental failure at a very early stage of embryonic development.
I'll never make that mistake again, reading the experts' opinions. - Feynman
ADHD medication? No. Depression medication? Yes.
Zyban, a fanfrickin'tastic smoking cessation pill, is simply remarketed Welbutrin. Welbutrin is an anti-depressant.
It seems that they discovered many of the smokers taking Welbutrin reported a marked decrease in cigarette cravings. Now you can buy the *exact* same drug with a different colour coating and a different name to help you quit smoking.
I have taken it. I was doing well, until a death in the family (non-cancer or smoking-related) buggered me up. Pathetic excuse, I know.
But while I was on Zyban I would literally go hours (unheard of any other time) without even thinking about a cigarette. It's really something else.