newty

What happens in urodeles is a specialized occurance. It has been demonstrated that in ideal conditions, in vitro, we can cause cells to dedifferentiate into stem cell-like cells. They are not stem cells, per se, but have some multipotential capability to proliferate and differentiate into other cell types. There are literally hundreds, if not thousands, of interactions (between proteins and cells) that result in a perfect regenerate. It is not possible for every newt to perfectly regenerate every single time. Humans lack this capability to do this so naturally. Well, with the exception of children regenerating fingertips. Also, while dedifferentiation is necessary for regeneration, stem cells from neighbouring tissues contribute towards this process. It is more complicated that what the magazine is saying (but I have not read the article). There are several theories out there of why they can, but we cannot regenerate. I have commented on this in an earlier thread. Newty

"Do you know other examples of self-healing surfaces?" As said above, I am unsure as to what you are actually asking. Are you asking about complex vs simple regeneration? Epidermal wound healing is an example of simple regeneration. Limb regeneration is a complex method. Nematode regeneration, starfish regeneration are both considered to be complex regeneration, although an argument can be made for these being labeled as simple regeneration. If you can clarify what you are asking for, we can help you better. Newty

Try cutting with only one enzyme. If the culprit is a bad enzyme, then you know your double digest is not working. Maybe the double digest reaction conditions are not optimal? Try a different buffer, more enzyme, let it go longer, etc. Newty

We need more info. What kind of vector is pBabe? Was it made in a lab or bought from a company? Do you know the sequence? Is this an eukaryotic- or prokaryotic-based study? Etc etc. Most eukaryotic genes begin translation with the ATG (usually defined by a Kozak consensus sequence), but is oftentimes posttranslationally modified. There is so much info out there. More info from you would help. Also, consult a good genetics textbook as it would definetly help you. Newty

My thinking is that the LEDS are turned on when only my actinic lights are on, and that the LEDS progressively get brighter and would be at full strength by the time the actinics turn off (1.5 hours) and vice versa for the dawn effect. Would the abovementioned equipment be sufficient for that task? My only experience with these LEDS is soldering the resistors and LEDS in parallel and wiring it to a normal wall adaptor. Newty

Basically. It may be longer than that as you may have to do an industrial postdoc to be a better applicant for industrial-based jobs, and there are not too many of these postdoc positions available. It is not easy, but it is doable. The trick out of all this is to network. Talk to people, know people, talk to people, be recognized for your work, talk to people, and so on. If you are great at networking, then you may even skip the postdoc route and land a industry job after graduation. There are a lot of PhD-MBA graduates out there. If you do go through this route, you will have a leg up on them. It helps if you go to a major recognized university for your MBA as the name, unfortunately, does play a major role in the initial screening of resumes for jobs. For PhD, it is not that important if your ultimate goal is industry. Newty

I stand corrected. Newty

I apologize for hijacking this thread, but I have another question: is it possible to dim LEDS in tandem? By anology, I would like to stimulate a dusk-dawn effect. Newty

Although it is not quite antigenic, but there are plenty of bacterial strains that recognize methylated DNA and digest these DNA. Not an immunological response, just thought to be an host defense mechanism. Many of the restriction enzymes used in molecular biology work are sensitive to certain kinds of methylation. DNA itself is recognized and chewed up when cells spill out their guts (cell lysis), and there are signals that recognize this. As far as being antigenic in eukaryotes, I do not know. Newty

If we could do that, then we could stop cancer in its tracks! It is a hard task to microinject solutions into a single cell in vitro (I know because I do this for my current project), yet alone try to microinject a substance in vivo. It is too difficult, if not almost impossible. It is possible to inject into a single cell in vivo, but identification of the cell(s) is another matter altogether. Most assays are done in vitro or ex vivo (usually fixed). Newty

Maybe I didnt mean a gun-style. What i meant that the handle is like a screwdriver and the metal unit slowly tapers toward the end and the end is a very fine point. I have used it before and it worked for other small appications. I don't know the terminology, unfortunately. I only know techie words for molecular sciences! Newty

Heatsink clamp: nope. Just have a soldering gun and some wire. I guess I will have to leave at least 3 mm as mentioned below. Probably will leave around 5 mm or something like that. Thanks, Newty

A quick question here... But, first a little background: I am planning on using LEDS to make a moonlight system for my saltwater tank (I have LEDS that produce output in the correct wavelength). I am planning on putting these LEDS inside a hollow acrylic tube to waterproof the connections. The inside diameter of these tubes are short. I am wondering if I could cut off the long extending wires from the LEDS (I cannot for the life of me think of the proper term) so that it would be shorter and I could easily orientate them in the acrylic tube. Is it ok to do this? Newty

Most people in the life sciences industry recommend that you get a postgraduate degree, then try to get a job in industry (you may have to do a postdoc first before appearing as a suitable candidate, though), work for 2-3 years, then get a MBA at the best school that you can get into. Then, you are a 'hot' commodity that companies flock to. It is highly recommended to get a PhD, because there is an invisible 'glass ceiling' in industry when it comes to workers that have a BSc or MSc. The majority of people going through the ranks are those that have PhDs. The reason why they recommend working in the industry for a few years is to obtain experience and know how the system works. Then get a MBA and, you should be a highly sought after candidate. That is what most insiders say. Getting a MBA first or concurently with your PhD is not worth it, accordign to them. Newty

Yes, some cells will react to a substance but others will not. I can add Shh to epidermal cells and they will proliferate like crazy. But, if I add this to, let's say, astrocytes they do not proliferate in such a response. Now, back to the oxygen theory. The theory behind cancer is that they proliferate quite rapidly, form new blood vessels via secretion of angiogenic substances that is thought to feed their high nutritional demand (oxygen and nutrients from blood). If you add more oxygen to the body (to the levels that is thought to be toxic to cancerous cells), then as stated above, it would be toxic to other 'normal' cells. Chemotherapy works to a certain degree. You can aim it to a certain body part, and the highly proliferative cells (i.e., tumourgenic cells) would accumulate more DNA mutations and be more susceptible to cell death. Normally, cancer cells have a strong anti-apoptotic response, but with enough mutations, they will be susceptible. The link you gave provides no info. I do not believe it unless I see the results. Preferably from a credible source such as a scientific organisation or journal that is peer reviews. Remember that just about anyone can say anything they want on the internet. Newty.

To the original question: no chance. Perhaps in a few centuries we may have accumulated enough knowlwdge and have the necessary technology to do it. But, practically speaking, it is highly improbable that one would get it to work. Now, getting it to work properly and obtaining the desired end result is another matter altogether. Chimeras are possible in vitro, but only in controlled circumstances with the right cells (most common example is the process of generating monoclonal antibodies). In vivo chimeras? Well, i can imagine that you can combine stem cells from organism a and organism b, but to get a fully functional chimera organism is quite hard. As mentioned above by Mokele, justification can stand in the way if you are going for public funds. Most likely if the technology/knowledge advacnes such that we can do this, it would be banned. What female wants to carry a fetus that probably has a 0.0001% chance of having no deformities. Disclaimer: I made up the number, so don't attack me about it or ask me to back it up. Coffee time is over. Newty

Most urodeles (salamanders and newts) have the capability to regenerate major structures and organs, although the degree of regeneration differs among species. The most common model organisms are the red-spotted newt (Notophthalmus viridescens) and the axolotl. They can regenerate lens, retina, limbs, jaw, and most organs, etc. What they cannot regenerate is the underlying tissues that flank the regeneration-competent structures. For example, they cannot regenerate muscle that flanks their forelimbs. What seperates animals that can regenerate from those who cannot. That is a big debate within the regenerative community. The short answer is that no one really knows. The long answer is that they think there are a lot of other factors, including a couple mentioned above. I will briefly list them: increased complexity (although this is only true up to a limited state in my opinion), occurence of cancer, immunological differences, genetic differences, and competency within cells. There are examples of regeneration outside of urodeles. There is a mouse model where the mice can regenerate ears and limbs. It was serependitically discovered because they original authors were studying some other gene (transgenic mouse model here), and they could not keep track of the litters with the ear punching method. Humans can regenreate the liver (although this is not true regeneration). Human children, up to a certain age can regenerate the tips of their fingers upon amputation, provided that the wound is not attended to by hospitalization (e.g., cauterized, skin flap pulled over the wound, etc). Chickens can regenerate eyes, too. Zebrafish can regenerate eyes and fins. African frogs can regenerate their structures, but only int he premetamorphic phase. Now, there are some studies otu there that have shown that adding certain factors can cause the occurence of regeneration. You see, in order for regeneration to occur, you need breakdown of the differentiated cells (a process called dedifferentiation), proliferatiion of these cells and redifferentiation to repopulate the missing appendage/organ. So, you need cues that break down cell-cell and cell-matrix environments, need cues to cause these cells to revert to an 'embryonic'-like state (lose their specialized cytoplasmic characteristics), cues to cause proliferation, cues to regulate migration, cues to cease proliferation, cues to intitiate redifferentiation and so on. There have been some factors that can cause the occurence of dedifferentiation (probably may be the most imporatnt step of regeneration - but each step is important anyways) including thrombin and msx1. If you do a Pubmed search of these with regeneration, you can find the original articles. If you have any other questions, let me know. Newty.