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How Stem Cells Work · Stuff You Should Know

• 0:01
  Speaker 1: Welcome to you Stuff you Should Know from house Stuff
• 0:04
  Speaker 1: Works dot com. Hey, and welcome to the podcast. I'm
• 0:13
  Speaker 1: Josh Clark. There's Charles W. Chuck Bryant that makes the
• 0:16
  Speaker 1: Stuff you Should Know, featuring Jerry Good Afternoon, Good afternoon, Charles.
• 0:24
  Speaker 1: How are you? I'm good? A little little wackier than
• 0:28
  Speaker 1: usual by maybe like three or four percent. Yeah, we're
• 0:30
  Speaker 1: both a little wacky today. Usually we depend on the
• 0:33
  Speaker 1: other to not be wacky. So this episode is going
• 0:36
  Speaker 1: to suck. No, it won't suck. You don't think. How
• 0:40
  Speaker 1: are you being optimistic? I see? I think if this
• 0:42
  Speaker 1: is good? I learned a lot about this topic. Yes,
• 0:46
  Speaker 1: thank you for not blowing the big secret. That's right.
• 0:49
  Speaker 1: We're talking about stem cells today. It's out there. Yep.
• 0:54
  Speaker 1: You can't take it back. Nope. Um, did you know
• 0:58
  Speaker 1: much about stem cells before? You researched the little bit?
• 1:00
  Speaker 1: Keep up with the news a little bit on it,
• 1:02
  Speaker 1: but I hadn't done a ton of research. It's really fascinating, Yeah,
• 1:06
  Speaker 1: it really is. What's funny is what I knew about
• 1:08
  Speaker 1: it before, what I assumed, um, which is just this
• 1:12
  Speaker 1: very primitive idea of like taking a cell and making
• 1:16
  Speaker 1: it turn into some other cell that you want and
• 1:18
  Speaker 1: then injecting it into the affected area. That's actually what
• 1:22
  Speaker 1: stem cell therapy is. Yeah, that's the goal of it
• 1:25
  Speaker 1: at this point pretty much yet one of them. Yeah,
• 1:28
  Speaker 1: so basically it's the Caveman stream. That's what stem cells are.
• 1:32
  Speaker 1: Is that what it is? Yeah? I thought that was
• 1:35
  Speaker 1: warm soup, warm soup alright, So after that, after warm
• 1:40
  Speaker 1: soup was invented, they turned their attention to stem cells.
• 1:43
  Speaker 1: Warm soup than cold beer stem cells. Yeah, that may
• 1:46
  Speaker 1: have come first. You remember from the beer episode the
• 1:49
  Speaker 1: idea that bread was created to make beer easier to make. Yeah,
• 1:54
  Speaker 1: that's such an awesome idea. I love it. That's a
• 1:57
  Speaker 1: T shirt right there. Yeah, it's a little plunk. I
• 2:00
  Speaker 1: think we need to work on bread before beer. Oh
• 2:02
  Speaker 1: well there you go. Yeah yeah, he thought I was
• 2:04
  Speaker 1: gonna put the whole thing. Yeah, it kind of keeps
• 2:07
  Speaker 1: going onto the back of the shirt. Right. Oh, wow,
• 2:10
  Speaker 1: you are in a weird mood today or inside? I know,
• 2:12
  Speaker 1: I just like, I let even know what that was. Okay,
• 2:15
  Speaker 1: let's let's take this seriously. Yes, so, um, there are
• 2:20
  Speaker 1: plenty of diseases out there, chuck that affects cells like
• 2:25
  Speaker 1: Parkinson's um. The neurons that produce dopamine, the neurotransmitter dopamine,
• 2:31
  Speaker 1: which helps control movements. UM, those cells die and as
• 2:35
  Speaker 1: a result, you lack dopamine and as a result of that,
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  Speaker 1: you can't control your movements, and then you have the
• 2:41
  Speaker 1: characteristic tremors of parkinson Um. Heart failure is apparently the
• 2:47
  Speaker 1: result of well, your heart failing, but the heart failure
• 2:50
  Speaker 1: comes from your heart cells dying off. It's all cellular
• 2:55
  Speaker 1: death for the most part, well a lot of it is, right,
• 2:58
  Speaker 1: there's a lot of disease out there, type one die abetes. UM.
• 3:01
  Speaker 1: I believe you're not producing insulin like you're supposed to
• 3:05
  Speaker 1: the pancreas. Yeah, So the reason why cell death in
• 3:08
  Speaker 1: the pancreas. So there's this whole idea that if you
• 3:12
  Speaker 1: can just figure out how to reintroduce these cells, then
• 3:17
  Speaker 1: the caveman's dream will be realized because you will have
• 3:20
  Speaker 1: a healthy pancreas and therefore no more type one diabetes.
• 3:23
  Speaker 1: You'll be producing UM dopamine again, no more Parkinson's and
• 3:27
  Speaker 1: possibly no more Alzheimer's either, yea, no more. A lot
• 3:30
  Speaker 1: of stuff, yeah, And it all comes down to the
• 3:33
  Speaker 1: fact that we are losing cells in a in an
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  Speaker 1: unnatural way, and there therefore, by replacing those cells, we
• 3:40
  Speaker 1: could conceivably cure these diseases. Yeah, I guess we shouldn't
• 3:43
  Speaker 1: say no more, but we should say reversible, you know,
• 3:46
  Speaker 1: because you would still get Parkinson's, but then you'd be
• 3:49
  Speaker 1: able to reverse the effects. We're not talking about eradicating.
• 3:53
  Speaker 1: Oh yeah, yeah, you know that's a that's a good point. Um, Yeah,
• 3:56
  Speaker 1: we're talking about curing these things once you already have them.
• 4:00
  Speaker 1: Just saved us some pedantic emails. So the whole point
• 4:06
  Speaker 1: to all this, the whole idea beneath it um was
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  Speaker 1: discovered in when some researchers figured out that there are
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  Speaker 1: cells in mice that are what are called undifferentiated, meaning
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  Speaker 1: they're not really any kind of cell, Like they don't
• 4:23
  Speaker 1: carry oxygen in the blood, they're not capable of it,
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  Speaker 1: they're not capable of UM transmitting neurotransmitters, they don't they
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  Speaker 1: didn't really seem to do anything. But then further and
• 4:35
  Speaker 1: further research revealed like, oh my god, these cells can
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  Speaker 1: do anything. Yeah. They're like a little child, like what
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  Speaker 1: kind of cell do you want to be when you
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  Speaker 1: grow up? And those are stem cells, and then I
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  Speaker 1: think they finally isolated them in humans because the big
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  Speaker 1: problem with stem cells is they look and seem just
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  Speaker 1: like all the other cells that they're around until you
• 4:57
  Speaker 1: figure out how to isolate them, which is something they're
• 5:00
  Speaker 1: actually still working on. That's right, and uh, they and
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  Speaker 1: we'll get to how they can mark these things, which
• 5:06
  Speaker 1: is pretty neat in a bit. But um, there are
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  Speaker 1: not nearly as many stem cells as uh is one
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  Speaker 1: of the main differences. Yeah, depending on where you look. Yeah,
• 5:14
  Speaker 1: for the adult and we'll get onto the different types
• 5:16
  Speaker 1: as well, but for adult stem cells, it's about one
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  Speaker 1: for every one thousand regular cells. Yeah, and again, like
• 5:22
  Speaker 1: in the blood, that's the case. In the bone you
• 5:24
  Speaker 1: might find one for every ten thousand. But the point
• 5:28
  Speaker 1: is there's not nearly as many stem cells because you
• 5:31
  Speaker 1: don't need as many. And the the analogy that I
• 5:35
  Speaker 1: guess they made in this article is that stem cells
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  Speaker 1: are kind of like the body's repair kit. Yeah. The
• 5:41
  Speaker 1: thing is is they don't necessarily do all the repairs
• 5:46
  Speaker 1: that we need, Like you can still get Parkinson's and
• 5:49
  Speaker 1: there's not a stem cell that automatically activates and cures
• 5:53
  Speaker 1: your Parkinson's. If so then this we wouldn't be having
• 5:55
  Speaker 1: this conversation, that's right. So the goal of stem cell
• 5:59
  Speaker 1: therapy used to figure out how to take these stem
• 6:01
  Speaker 1: cells and make them do what you want them to do. Yeah,
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  Speaker 1: manipulating these cells to to turn into helpful cells. Regular
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  Speaker 1: cells can only replicate um to be another kind of
• 6:15
  Speaker 1: that cell, but stem cells are. They have different levels
• 6:18
  Speaker 1: of what's called potency, which is an ability to change,
• 6:22
  Speaker 1: ranging from a tote potent which can develop into anything anything,
• 6:27
  Speaker 1: like it can turn into a car if it wants to.
• 6:30
  Speaker 1: That's not true, it's like the Wonder Twins. Yeah, it
• 6:33
  Speaker 1: can turn to anything, so long as it's water based,
• 6:35
  Speaker 1: that's right. Uh. And then you have other levels of
• 6:38
  Speaker 1: potency to pluripotent, multipotent, um. And we'll cover all this
• 6:42
  Speaker 1: in detail as we go, because each one has a
• 6:44
  Speaker 1: different potency level, right. But I think that was descending
• 6:47
  Speaker 1: order from uh capability, right, Like toted potent is anything, Yeah,
• 6:53
  Speaker 1: pluripotent is almost anything. Then multipotent is a few things. Um.
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  Speaker 1: And we have uh, these stem cells, like we said,
• 7:03
  Speaker 1: around the body in different places and and like you said,
• 7:06
  Speaker 1: their their job is to basically hang out in there.
• 7:09
  Speaker 1: Call it like their host organ or their host tissue. Yeah,
• 7:12
  Speaker 1: like we're all in the liver. We're liver cells, right,
• 7:14
  Speaker 1: So you need a new you need a few liver cells. Here,
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  Speaker 1: I'm going to divide. I'm gonna divide into some more
• 7:22
  Speaker 1: and then bam, no more cirrhosis, or at least it's
• 7:25
  Speaker 1: staved off for another year. UM. With the bone marrow
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  Speaker 1: in particular, UM, there's a type of cell, or a
• 7:34
  Speaker 1: type of stem cell called stromal stem cell, and that
• 7:37
  Speaker 1: one UM creates all sorts of different types of blood cells. UM.
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  Speaker 1: Because your blood cells that's how they regenerate. Your stem
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  Speaker 1: cells they don't self regenerate, and they only last about
• 7:48
  Speaker 1: twenty eight days. Now, is that why you can use
• 7:50
  Speaker 1: UM cells from bone marrow to treat other diseases like leukemia,
• 7:54
  Speaker 1: other blood diseases? Exactly? And that is a procedure. It's
• 7:59
  Speaker 1: actually stem cell therapy that predated our awareness that stem
• 8:03
  Speaker 1: cells even existing. We just didn't call it a stem
• 8:05
  Speaker 1: cell at the time. Yeah, it's a bone marrow transplant.
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  Speaker 1: That's what people still call it now we understand that
• 8:10
  Speaker 1: what you're actually doing is transplanting that marrow that includes
• 8:14
  Speaker 1: some bone marrow stem cells. Yeah, into another person, and
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  Speaker 1: then those stromal stem cells will start to regenerate and
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  Speaker 1: help the person who has accepted this donation. That's right.
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  Speaker 1: So that was the that's that that happened even before
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  Speaker 1: we understood what stem cells were. But sin Um, all
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  Speaker 1: of this research has really been focused on, Okay, how
• 8:38
  Speaker 1: can we make this a little more guided and laser
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  Speaker 1: focused rather than accidentally transplanting stem cells from one person's
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  Speaker 1: bone marrow to another. And so what they started to
• 8:49
  Speaker 1: investigate and found, Chuck, was that, uh, there's something called
• 8:53
  Speaker 1: embryonic stem cells. And these were the first ones that
• 8:56
  Speaker 1: were like this is awesome. Yeah, And like you said,
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  Speaker 1: they were isolated in humans and due to private funding,
• 9:03
  Speaker 1: which is important designation because we'll get to all the
• 9:07
  Speaker 1: controversies and federal funding coming up soon. But they are embryonic.
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  Speaker 1: They're in the embryo, the fetus, or the umbilical cord blood,
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  Speaker 1: which is why a lot of times um mothers will
• 9:19
  Speaker 1: save their umbilical cord or not themselves. They don't give
• 9:23
  Speaker 1: it to them here you go, because that could come
• 9:30
  Speaker 1: in handy later on um and it depends on what
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  Speaker 1: it's harvested. But they are the ones that are pluripotent,
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  Speaker 1: depending like I said, on when you get them. They
• 9:40
  Speaker 1: can also very early on the the ultimate uh tote potent.
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  Speaker 1: But that's um, that's super early. Yeah, you have to
• 9:48
  Speaker 1: have a quick hand like this total day or so
• 9:50
  Speaker 1: right old um. So those are the embryonic versions. Then
• 9:56
  Speaker 1: you've got adult stem cells and um. Strangely a ault
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  Speaker 1: stem cells are found from infants on. So I think
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  Speaker 1: the adult refers to the actual stem cell rather than
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  Speaker 1: the person who has that type of stem cell. Yeah.
• 10:09
  Speaker 1: I think it's like I guess, just sort of like
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  Speaker 1: post embryonic is the way I looked at it. Yeah, yeah,
• 10:16
  Speaker 1: that makes sense. It is multipotent, which means it can
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  Speaker 1: uh differentiate or change itself into a lot of different
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  Speaker 1: helpful things, but not as many as pluripotent. No. Um.
• 10:27
  Speaker 1: And then lastly, in two thousand and six, some Japanese
• 10:30
  Speaker 1: people figured out that you could English. Were they English too? Well,
• 10:35
  Speaker 1: those two guys who won the Nobel Prize, it was
• 10:37
  Speaker 1: Japanese one was they both deserve it because they figured
• 10:42
  Speaker 1: out that you can take uh sell any kind of
• 10:46
  Speaker 1: cell and make it regress back into a stem cell.
• 10:51
  Speaker 1: And that was huge because in part or mostly because
• 10:57
  Speaker 1: of the big controversy around embryonic stem cells, which you said,
• 11:00
  Speaker 1: we'll get into it in depth. Yeah, those are called
• 11:03
  Speaker 1: induced pluripotent stem cells or I P S C S
• 11:06
  Speaker 1: induced because they're inducing it in pluripotent because they revert
• 11:10
  Speaker 1: back to uh, the very handy uh pluripotent stage. Uh.
• 11:15
  Speaker 1: Those are the main three that's in general, and we'll
• 11:17
  Speaker 1: talk about all of them a little more in that
• 11:19
  Speaker 1: right after this. All right, so let's start with embryonic.
• 11:25
  Speaker 1: That seems like the logical place. Uh. If you listen
• 11:29
  Speaker 1: to our in vitro fertilization podcast recently, you know all about, UM,
• 11:35
  Speaker 1: how an embryo is formed. We have an egg fertilized
• 11:37
  Speaker 1: by a sperm that divides becomes an embryo. It's basically
• 11:41
  Speaker 1: that simple. I encourage you to go listen to that podcast,
• 11:43
  Speaker 1: though you'll learn all about all kinds of stuff. When
• 11:46
  Speaker 1: you undergo IVF though, like we talked about in that episode,
• 11:50
  Speaker 1: a lot of times you will have more embryo's not
• 11:52
  Speaker 1: always um, but a lot of times you have more
• 11:55
  Speaker 1: embryos than you're gonna use, and so you can freeze
• 11:58
  Speaker 1: those and save them for later in case you get
• 12:00
  Speaker 1: pregnant and that doesn't work out, um or it just
• 12:04
  Speaker 1: becomes medical waste. You get pregnant, you're like, we don't
• 12:06
  Speaker 1: need those anymore. You can just discard them, or you
• 12:09
  Speaker 1: can go with option three, which is to donate them
• 12:12
  Speaker 1: uh to science to be used in stem cell cloning,
• 12:15
  Speaker 1: therapeutic cloning. UM. The reason that they would want your
• 12:20
  Speaker 1: embryos is because, like you said, there at some point
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  Speaker 1: total potent and definitely plural potent, very very versatile as
• 12:30
  Speaker 1: far as stem cells go. UM, and you can it's
• 12:34
  Speaker 1: very It's not easy. I don't think it's I don't
• 12:37
  Speaker 1: think that's the right word. But you can take a
• 12:40
  Speaker 1: embryonic stem cell and culture it and let it divide
• 12:44
  Speaker 1: into more and then culture those and culture those, and
• 12:46
  Speaker 1: as long as they stay undifferentiated, you have a line
• 12:50
  Speaker 1: of stem cells that can just keep replicating more and
• 12:54
  Speaker 1: more stem cells. They're never going to turn into a
• 12:57
  Speaker 1: certain kind of cell, that's right. So what you've just
• 13:00
  Speaker 1: created is an embryonic stem cell line. The thing is,
• 13:03
  Speaker 1: and this is what people have a problem with. To
• 13:06
  Speaker 1: harvest these things, you have to destroy the embryo. You
• 13:09
  Speaker 1: have to you have to let it become a blasticist,
• 13:12
  Speaker 1: which takes a couple of days, and by the time
• 13:14
  Speaker 1: it becomes a blasticist, it's about a hundred cells wide
• 13:18
  Speaker 1: or deep. There's and then inside this is the the
• 13:24
  Speaker 1: embryonic stem cells. So basically you have to crack the
• 13:26
  Speaker 1: blast eist open and then harvest the stem cells, and
• 13:30
  Speaker 1: then there's nothing left to do with the the blasticist.
• 13:34
  Speaker 1: If you're a religious type and you believe that life
• 13:37
  Speaker 1: begins at conception, then the problem is is you've just
• 13:40
  Speaker 1: taken a life by destroying a blasticist, and uh, that's
• 13:45
  Speaker 1: just one of the controversies. The therapeutic cloning is also
• 13:48
  Speaker 1: controversial because that's when they merge a cell. You've got
• 13:52
  Speaker 1: a patient who needs the therapy, and they merge that
• 13:55
  Speaker 1: cell with a donor's egg and then remove the nucleus
• 13:59
  Speaker 1: from that egg, replace it with the patients and it
• 14:01
  Speaker 1: basically is like their own. Now it's it's not likely
• 14:06
  Speaker 1: to be rejected, which is a big problem. You're just
• 14:09
  Speaker 1: basically using someone else's egg for its structural capabilities, and
• 14:14
  Speaker 1: but the nucleus the thing that's saying like here, build this,
• 14:17
  Speaker 1: go do this. It's it's going to look like you,
• 14:19
  Speaker 1: not them. Yeah, but anytime you use that c word, uh, cloning. Yeah,
• 14:24
  Speaker 1: well it's going to be controversy is going to ensue,
• 14:26
  Speaker 1: of course indeed. But it's also a double controversy too,
• 14:29
  Speaker 1: because you have to do the same thing. You're still
• 14:32
  Speaker 1: forming an embryo that you destroy once it gets the
• 14:34
  Speaker 1: blasts of stage. It's just a freak of nature because
• 14:37
  Speaker 1: you cloned it. It's called a double whammy. Right. So
• 14:41
  Speaker 1: that was that's embryonic and you know, there's a lot
• 14:45
  Speaker 1: of controversy around it. Um and we'll talk about that
• 14:49
  Speaker 1: a little more later. But there's another type of stem
• 14:53
  Speaker 1: cell um that isn't nearly as controversial, if at all,
• 14:57
  Speaker 1: and that's the adult stem cell which we mentioned, which
• 15:00
  Speaker 1: doesn't mean you have only when you're an adult, but
• 15:02
  Speaker 1: it's a type of stem cell that it's like the
• 15:05
  Speaker 1: kind that hangs out in your bone marrow. It's it
• 15:08
  Speaker 1: has a more of a specialized um job. Yeah, or
• 15:13
  Speaker 1: it can become specialized, which is the key. Uh. And
• 15:16
  Speaker 1: as you said, it hangs out and it can divide
• 15:19
  Speaker 1: and help out the liver if it needs to, or
• 15:22
  Speaker 1: the pancreas if it needs to. And um, that's the
• 15:27
  Speaker 1: main differentiate is that it's it's multipotent instead of pluripotent.
• 15:31
  Speaker 1: It still has limits. UM, And it's basically again this
• 15:36
  Speaker 1: is these are the ones that are your They're not
• 15:39
  Speaker 1: there to create you the human for the first time.
• 15:43
  Speaker 1: They're there to kind of keep you from wearing down
• 15:45
  Speaker 1: too fast. Yeah, I wonder if I wonder if they're
• 15:48
  Speaker 1: left over or if they're supposed to be there. I
• 15:51
  Speaker 1: know that sounds like a weird differentiation. I don't know,
• 15:54
  Speaker 1: because I did see somewhere that um, they're still trying
• 15:58
  Speaker 1: to figure out although this Japanese research may have figured
• 16:02
  Speaker 1: it out, but they're trying to figure out why some
• 16:04
  Speaker 1: types of stem cells, adults stem cells, we'll just sit
• 16:07
  Speaker 1: there and just hang out for a very long time,
• 16:11
  Speaker 1: and then all of a sudden they start to divide.
• 16:13
  Speaker 1: So I don't know, maybe they are original cells. If
• 16:16
  Speaker 1: they're just kind of hanging out doing nothing, why would
• 16:18
  Speaker 1: they age? I don't know. You know, it's weird. So
• 16:21
  Speaker 1: we mentioned earlier that they one of the difficulties in
• 16:24
  Speaker 1: working with stem cells, especially these adults them cells as
• 16:27
  Speaker 1: they looked like other cells. So they have a really
• 16:29
  Speaker 1: cool way of of marking them, or what they call
• 16:32
  Speaker 1: lighting them up um or cells. UM. Every cell has
• 16:36
  Speaker 1: a unique protein called a receptor on the surface and
• 16:39
  Speaker 1: they bind these chemical messages. That's how cells talk to
• 16:42
  Speaker 1: each other basically, And so they use these markers UM
• 16:46
  Speaker 1: to identify the adults them cells. They basically tag them,
• 16:49
  Speaker 1: tag these chemical messages with fluorescent molecules and then once
• 16:54
  Speaker 1: they put that fluorescent chemical in there, it lights up
• 17:00
  Speaker 1: under a fluorescent light, so they make them kind of
• 17:01
  Speaker 1: glow in the dark. Yeah, because that chemical message is
• 17:04
  Speaker 1: now bound to the only type of cell that's it
• 17:07
  Speaker 1: will bind to the stem cell. So then yeah, when
• 17:10
  Speaker 1: you hit it with the black light, somebody should have
• 17:12
  Speaker 1: won a Nobel price for that too, in my opinion,
• 17:16
  Speaker 1: black light. But it's the same as embryonic stem cells. UM.
• 17:21
  Speaker 1: You can grow these in a petri dish. You can
• 17:24
  Speaker 1: establish a new cell line, and they are extremely useful.
• 17:27
  Speaker 1: And like you said there, they naturally say in the liver,
• 17:31
  Speaker 1: create new liver cells. But they have been shown UM
• 17:38
  Speaker 1: trans differentiation to undergo trans differentiation where they can be
• 17:42
  Speaker 1: induced to do something slightly different. So like a liver
• 17:48
  Speaker 1: stem cell can produce insulin, which is typically produced in
• 17:52
  Speaker 1: the pancreas, right, and they haven't. Um, they haven't quite
• 17:55
  Speaker 1: figured that out yet, right, No, No, they do not
• 17:58
  Speaker 1: know this. Like they know that stems somehow can be
• 18:01
  Speaker 1: induced to do different things, they don't know how to
• 18:04
  Speaker 1: do it yet. Yeah, this is all super new stuff
• 18:07
  Speaker 1: for the most part, I mean, if you're talking since
• 18:09
  Speaker 1: not a long time. They did recently figure out these
• 18:13
  Speaker 1: uh hemo poet poietic Yeah, hemopoietic stem cell, which is
• 18:19
  Speaker 1: a it's a type of blood stem cell that makes
• 18:21
  Speaker 1: all different kinds of blood cells. It's a very important one.
• 18:25
  Speaker 1: And they found that by looking at zebra fish embryos,
• 18:30
  Speaker 1: which are totally transparent. Um, they actually watched these things
• 18:34
  Speaker 1: form and they just found out, like within the last
• 18:37
  Speaker 1: couple of weeks that these require what they're calling a
• 18:40
  Speaker 1: buddy cell to become the type of stem cell that
• 18:44
  Speaker 1: forms blood. Right, So now they think that they're one
• 18:47
  Speaker 1: step closer to figuring out these hemopoieticum stem cells. They
• 18:53
  Speaker 1: don't know what the buddy cell is or where it
• 18:55
  Speaker 1: comes from, but then now they know that it needs
• 18:57
  Speaker 1: a buddy so that these are kind of like these
• 19:00
  Speaker 1: of the kind of piecemeal steps that we're making towards
• 19:03
  Speaker 1: understanding stem cells. All right, and then we have our
• 19:06
  Speaker 1: well maybe not final because you've already told us about
• 19:08
  Speaker 1: the fourth, but the third uh type is what we
• 19:12
  Speaker 1: call the induced pluri potent stem cell. And um, that's
• 19:17
  Speaker 1: the one that we mentioned was pioneered by Shinya Yamanaka.
• 19:22
  Speaker 1: And Sir John almost said, Sir John Gruden. So, Sir
• 19:27
  Speaker 1: John Gerdon, Well, who's John Gruden? And sounds so familis
• 19:31
  Speaker 1: the NFL coach that looks like, oh yeah, Chucky Job's play.
• 19:36
  Speaker 1: He didn't win a Nobel Prize though, but for their
• 19:38
  Speaker 1: efforts in two thousand twelve, they did win a Nobel Prize.
• 19:42
  Speaker 1: And uh, basically, like you said, they found a way
• 19:45
  Speaker 1: to induce these cells to return to their embryonic state,
• 19:50
  Speaker 1: which is amazing. Yeah, it sounds like basically they're using epigenetics. Yeah,
• 19:57
  Speaker 1: that's a dangerous word to say, too. Well, think of
• 20:00
  Speaker 1: so like a cell. What they found is that cells
• 20:03
  Speaker 1: change and become the way that they later become, like
• 20:06
  Speaker 1: a liver cell or a bone cell or a neuron
• 20:09
  Speaker 1: or something like that, because they all have the same
• 20:12
  Speaker 1: genetic code in them. But then certain gene sequences are
• 20:17
  Speaker 1: either turned on or off in that cell and that
• 20:19
  Speaker 1: changes or tells them or directs them to become what
• 20:22
  Speaker 1: kind of cell they become. Right, what these guys have
• 20:25
  Speaker 1: done is introduced what are called stem cell factors that
• 20:29
  Speaker 1: go in and switch everything off to turn them back
• 20:33
  Speaker 1: into these plury potent stem cells. The thing that they
• 20:37
  Speaker 1: haven't figured out how to do yet is to now
• 20:39
  Speaker 1: activate them, to say, here's some new markers to change
• 20:44
  Speaker 1: your your gene sequence and uh now become uh liver cell.
• 20:51
  Speaker 1: Keep coming back to liver cells. I'm fixated on that. Um,
• 20:55
  Speaker 1: that's that's the next step. Yeah. And the great thing
• 20:59
  Speaker 1: about the I P s C is that it doesn't
• 21:01
  Speaker 1: involve embryos, so that kind of skirched the ethical and
• 21:04
  Speaker 1: political side of things. Yeah, because you can take a
• 21:07
  Speaker 1: skin cell and again, these guys are having a one
• 21:10
  Speaker 1: percent success rate, which is not bad. No, but if
• 21:13
  Speaker 1: you if if this, uh this other researcher has figured
• 21:16
  Speaker 1: out how to make them at that's even better. Yeah.
• 21:21
  Speaker 1: And these are it's such a new um, a new
• 21:24
  Speaker 1: process with the I s PC is they need to
• 21:28
  Speaker 1: do research to see how effective they are in treatment. Uh,
• 21:31
  Speaker 1: if they are identical to embryonics themselves, or if they
• 21:34
  Speaker 1: just behave a lot like them. Um, So the proof
• 21:38
  Speaker 1: in the pudding will becoming hopefully in recent and uh
• 21:42
  Speaker 1: in the coming years exactly, not recent years, in coming years,
• 21:46
  Speaker 1: in coming years. So Chuck, let's talk about how they
• 21:50
  Speaker 1: hope to actually use stem cells in the future once
• 21:52
  Speaker 1: they have mastered these things after this. Okay, So using
• 22:06
  Speaker 1: the stem cells is very important. You can create all
• 22:08
  Speaker 1: these cell lines and they can live a very great
• 22:11
  Speaker 1: life in a petri dish. But unless we're saving lives
• 22:14
  Speaker 1: and reversing disease, um, what good are they? Well, so
• 22:18
  Speaker 1: far no good. But hopefully what they're what they're thinking of,
• 22:22
  Speaker 1: is they'll be able to use these things for say
• 22:24
  Speaker 1: like drug drug trials. Yeah, that's huge, because right now
• 22:28
  Speaker 1: what you have to do is test something on an
• 22:29
  Speaker 1: animal and then think, all right, well, if it does
• 22:33
  Speaker 1: this in a mouse, let's try and figure out how
• 22:36
  Speaker 1: it might work in a human instead of just testing
• 22:39
  Speaker 1: it directly on human cells. Apparently the steps you followed
• 22:43
  Speaker 1: are mouse, monkey, human, unless there's in a bowl outbreak
• 22:48
  Speaker 1: and then you just go straight to human. Get the
• 22:51
  Speaker 1: FDA to pass it. Right. So, if you're if you're
• 22:55
  Speaker 1: creating like a heart drug or something, and you can
• 22:57
  Speaker 1: induce some um, stem cell else to become heart cells,
• 23:01
  Speaker 1: heart tissue, and then test the drug out on this.
• 23:05
  Speaker 1: You're basically just running human trials right there. Yeah, you're
• 23:08
  Speaker 1: skipping steps, you're saving time, you're saving money, cutting corners. Ah, yeah,
• 23:13
  Speaker 1: that is a negative. So that's one that is one
• 23:18
  Speaker 1: idea behind a good way to use these stem cells.
• 23:23
  Speaker 1: Let them stop living their life of leisure and start
• 23:26
  Speaker 1: contributing for once. Yeah, and forget the drug trials. Maybe
• 23:30
  Speaker 1: they can actually, like you said earlier, I think of
• 23:33
  Speaker 1: the beginning, just inject it right into the heart, let's say,
• 23:37
  Speaker 1: to repair damage tissue. And they they've actually had some
• 23:41
  Speaker 1: success with this and mice. Again, our understanding of some
• 23:44
  Speaker 1: stem cells and what they're doing is kind of primitive.
• 23:47
  Speaker 1: But they took mice with bad tickers and they injected
• 23:52
  Speaker 1: them with heart stem cells, and um, all of a sudden,
• 23:57
  Speaker 1: the mice had like super hearts. But they don't know
• 24:00
  Speaker 1: if these stem cells went in and regrew heart like,
• 24:03
  Speaker 1: cardiac muscle tissue, new blood vessels. They're not sure why.
• 24:07
  Speaker 1: They just know that the mice the arts. Yeah, yeah,
• 24:13
  Speaker 1: we're better. Uh. And as they go along testing all
• 24:16
  Speaker 1: these things, one of the things they have to get around.
• 24:18
  Speaker 1: One of the hurdles is um rejection, like uh, bone
• 24:22
  Speaker 1: marrow transplant, any kind of transplant on the body. Really
• 24:25
  Speaker 1: there's a chance that your body will reject it and
• 24:28
  Speaker 1: say this is a foreign invader, maybe going and attack
• 24:30
  Speaker 1: it and kill it. Um. But one of the cool
• 24:34
  Speaker 1: things about the I P s C Is since it
• 24:37
  Speaker 1: comes from your own body, has a probably a greater
• 24:40
  Speaker 1: chance of not being rejected. Yeah. Same with using adult
• 24:44
  Speaker 1: stem cells. They're gonna take them from you and use
• 24:47
  Speaker 1: them on yourself. So that's very promising as well. So, Chuck,
• 24:50
  Speaker 1: we've been kind of skirting around this issue a little bit,
• 24:53
  Speaker 1: but um, we we may mention that embryonic stem cells
• 24:57
  Speaker 1: do represent a very controversial piece of scientific research because
• 25:04
  Speaker 1: to some they represent the destruction of life. Yeah, and
• 25:09
  Speaker 1: it it all kind of got started with the Clinton administration. UM.
• 25:13
  Speaker 1: The National Institute of Health Human Embryo Research Panel advised
• 25:18
  Speaker 1: Billy Boy to authorize funding for research on leftover embryos
• 25:25
  Speaker 1: from IVF treatments that we mentioned, uh, and to create
• 25:29
  Speaker 1: new embryos um from scratch for research purposes. And he said,
• 25:36
  Speaker 1: the first one sounds good, but I don't know about
• 25:39
  Speaker 1: that second one. Let me ask new gingrids. Can you
• 25:43
  Speaker 1: say that, like, like Clinton, let me ask new Gingrich.
• 25:48
  Speaker 1: I thought you were asking me to do a new Gingrich.
• 25:50
  Speaker 1: I was like, I have no idea how to do.
• 25:51
  Speaker 1: He was pretty Uh he didn't have like a very
• 25:55
  Speaker 1: remarkable accent, especially not for being in Georgian. Yeah, that's true. Um.
• 26:00
  Speaker 1: So that was and um, like we said, in is
• 26:04
  Speaker 1: when things really got rolling because of private funding. But
• 26:07
  Speaker 1: by then Congress had already put the brakes on it. Yep,
• 26:10
  Speaker 1: because in n there was a writer on another bill
• 26:13
  Speaker 1: called the Dickey Wicker Amendment from J. Dickey and Roger Wicker.
• 26:17
  Speaker 1: Doesn't that sound like a British amendment? It does? The
• 26:21
  Speaker 1: Wicker um probably because of Sticky Wicket in cricket, right right. Uh.
• 26:27
  Speaker 1: And they proposed banning federal funding for any research in
• 26:32
  Speaker 1: which you destroy the embryo. Yeah, so I mean, like
• 26:35
  Speaker 1: it wasn't specifically limited to stem cell research, but like
• 26:40
  Speaker 1: we said, to get to the stem cells, you have
• 26:42
  Speaker 1: to crack open the blast asist, which destroys the embryo,
• 26:45
  Speaker 1: which in effect put the freeze on creating any new
• 26:49
  Speaker 1: stem cell lines pretty much. And they've renewed it every
• 26:52
  Speaker 1: year since then. Um. But like anything in the US government,
• 26:56
  Speaker 1: there's all sorts of ways to get around it, and
• 26:58
  Speaker 1: one is the executive order. Right. And Bush came in
• 27:02
  Speaker 1: and he issued his own executive orders, right, which kind
• 27:05
  Speaker 1: of strengthened the existing rules on embryonic research. Yeah, and
• 27:11
  Speaker 1: that's the one where he said you could use federal
• 27:13
  Speaker 1: funds only on those established lines, either the nineteen or
• 27:17
  Speaker 1: the twenty two, uh, depending on guess where you're getting
• 27:20
  Speaker 1: your info. And um, it prevented basically any funding federal
• 27:26
  Speaker 1: funding for creating these new lines. Um. So, like you
• 27:29
  Speaker 1: said earlier, I think they were grandfathered in, right. And
• 27:33
  Speaker 1: and the problem with that is, I mean, these stem
• 27:36
  Speaker 1: cell lines can produce millions of new stem cells and
• 27:39
  Speaker 1: within a matter of months, but you need even more
• 27:43
  Speaker 1: for decent research. So there was in the United States
• 27:47
  Speaker 1: at least a lot of there was a huge freezing
• 27:49
  Speaker 1: effect on stem cell research. It just wasn't nearly as
• 27:54
  Speaker 1: widespread as it could be, at least if you wanted
• 27:57
  Speaker 1: federal funding for your lab. Yeah. Um. And so under Bush,
• 28:02
  Speaker 1: the I guess there was just there was still this
• 28:05
  Speaker 1: huge national debate about it, and the Bush administration sided
• 28:09
  Speaker 1: with the pro life lobby and said no, you guys
• 28:14
  Speaker 1: can just do this, but how about this, I mean
• 28:18
  Speaker 1: to issue an executive order encouraging you to go figure
• 28:20
  Speaker 1: out a way to start new stem cell lines without
• 28:23
  Speaker 1: destroying embryos. Go, and I guess you can kind of say. Well,
• 28:29
  Speaker 1: then after that there was the induced plur potent stem cells.
• 28:34
  Speaker 1: I think they were probably already working on those. I
• 28:35
  Speaker 1: don't know if it was a tribute to Bush's challenge
• 28:38
  Speaker 1: or anything like that, but it did come after that. Yeah,
• 28:42
  Speaker 1: So that was all in two thousand one ish, and
• 28:45
  Speaker 1: then UH in two thousand five. By the time that
• 28:47
  Speaker 1: came around, UM, the House and the Senate both UM,
• 28:53
  Speaker 1: even modern Republicans started to kind of get on board
• 28:55
  Speaker 1: a little bit more, say, Hey, maybe we need to
• 28:57
  Speaker 1: broaden this thing a little bit because it's super promising.
• 29:00
  Speaker 1: So let's introduce a couple of a couple of acts,
• 29:04
  Speaker 1: the Stem Cell Research Enhancement Act of two thousand five,
• 29:07
  Speaker 1: and that would have allowed federal funding of research on
• 29:11
  Speaker 1: UH these new lines, not those grandfathered in only from
• 29:14
  Speaker 1: the discarded embryos um from fertility treatments. The House passed
• 29:19
  Speaker 1: it to UH. Senate passed it six three to thirty seven,
• 29:24
  Speaker 1: and Bush vetoed that. He said he was gonna veto it.
• 29:26
  Speaker 1: It's one of those deals. He's like, go ahead and vote,
• 29:28
  Speaker 1: I'm gonna veto it. They voted, he vetoed it. Uh,
• 29:31
  Speaker 1: they did not. They tried to override the veto the
• 29:34
  Speaker 1: House did, but they failed to. And then the stem
• 29:36
  Speaker 1: Cell Research Enhancement Act of two thousand seven was similar
• 29:41
  Speaker 1: to the original and two thousand five that passed the
• 29:44
  Speaker 1: Senate and House as well, and uh, Bush vetoed that
• 29:47
  Speaker 1: one as well. Okay, so that was the climate that
• 29:50
  Speaker 1: the Obama comes in. Yeah, and and uh again he
• 29:54
  Speaker 1: you know, Bush wasn't saying I hate stem cell research.
• 29:56
  Speaker 1: It's it's stupid and I want people to die. He
• 30:00
  Speaker 1: was saying, we should only do it in certain ways
• 30:04
  Speaker 1: that don't violate, Uh, what a lot of people feel
• 30:07
  Speaker 1: like are you know, life begins that, you know that
• 30:11
  Speaker 1: very first day? Right, So Obama comes in and says,
• 30:13
  Speaker 1: forget that, if you have your nineteen or twenty two
• 30:18
  Speaker 1: stem cell lines, you can get federal funding for working
• 30:20
  Speaker 1: on those lines. Everybody, that's cool, And how about some
• 30:23
  Speaker 1: new lines? If somebody is going to discard embryos from
• 30:27
  Speaker 1: in vitro fertilization, and they want to donate them. And
• 30:30
  Speaker 1: these people are aware that these things are going to
• 30:33
  Speaker 1: be used for medical research. Then you can create new
• 30:36
  Speaker 1: stem cell lines using federal funding and that you're not
• 30:40
  Speaker 1: paying those people. That was the final step. Yeah. Um.
• 30:43
  Speaker 1: And so a couple of ironically, a couple of stem
• 30:46
  Speaker 1: cell researchers sued um to get these rules stopped from
• 30:51
  Speaker 1: being put into place. Um, and they actually won. Uh.
• 30:56
  Speaker 1: Their case was overturned on appeals I believe, who basically
• 31:02
  Speaker 1: also said, you know what this uh, what is it?
• 31:05
  Speaker 1: The Dicky Whate Amendment, the sticky wick, the wick, the
• 31:09
  Speaker 1: Dicky Wicker Amendment is overly broad, and so we're gonna
• 31:12
  Speaker 1: limit this and everything. Obama just said in his an
• 31:15
  Speaker 1: executive order, just go ahead, and we're gonna go forward
• 31:18
  Speaker 1: with those rules. So that's the current state of affairs
• 31:21
  Speaker 1: right now, is an appeals court interpreted this legislative act
• 31:26
  Speaker 1: is overly broad, and we're operating under an executive order
• 31:31
  Speaker 1: that's allowing federal funding for embryonic stem cell research to continue.
• 31:36
  Speaker 1: Nothing's really changed as far as the national conversation goes.
• 31:39
  Speaker 1: It feels like it's just died down. A bit as
• 31:43
  Speaker 1: far as the volume goes. And um, they've never banned research.
• 31:48
  Speaker 1: It's just a matter of restrictions on federal funding and use. Um. Yeah,
• 31:53
  Speaker 1: well they also didn't ban research on gun violence. They
• 31:58
  Speaker 1: just stopped funding that too. That's right, remember that I do. Yeah,
• 32:02
  Speaker 1: you got anything else? I got nothing else? Okay, Well
• 32:07
  Speaker 1: that's stem cells at least as far as um it
• 32:10
  Speaker 1: goes in August two thousand fourteen. Yeah, two thousand fourteen.
• 32:16
  Speaker 1: I'm sure that in five years it's gonna be a
• 32:19
  Speaker 1: whole new world. Yeah, you never know, we might see
• 32:22
  Speaker 1: the end of Parkinson's and MS and Alzheimer's and it
• 32:26
  Speaker 1: just inject some new cells in there. Uh. If you
• 32:29
  Speaker 1: want to more about stem cells, you can type those
• 32:31
  Speaker 1: words into the search part how stuff works dot com.
• 32:34
  Speaker 1: And uh, since I said search parts, time for a
• 32:36
  Speaker 1: listener mail. I'm gonna call this banana flavoring. Um. I
• 32:40
  Speaker 1: can't remember which podcast it was, Plato, but um I
• 32:45
  Speaker 1: said that I didn't never like banana flavoring and stuff,
• 32:48
  Speaker 1: but I like bananas, and you were like what. We
• 32:52
  Speaker 1: got quite a few emails explaining this, and I'm super
• 32:54
  Speaker 1: happy because I get it now. Um, and this is
• 32:56
  Speaker 1: from Elliott. Um, you guys seem to be unaware of
• 33:00
  Speaker 1: why the flavor is different. Currently, we most commonly enjoy
• 33:04
  Speaker 1: what is called the Cavendish banana. Have you ever heard
• 33:08
  Speaker 1: of that? Yeah? I did it. Don't be dumb on
• 33:11
  Speaker 1: banana clone? Oh you did? Well? How about that? Uh?
• 33:15
  Speaker 1: There are the long yellow bananas people like to have
• 33:17
  Speaker 1: on their Sundays. Before the nineteen sixties, and most commonly
• 33:21
  Speaker 1: purchased banana was the the big Mic or the gross Mikael.
• 33:27
  Speaker 1: I guess it came from Germany. It's definitely gross means big. Uh.
• 33:32
  Speaker 1: There are the bananas. These are the bananas that banana
• 33:35
  Speaker 1: candy is based on. Um. After Panama disease, which was
• 33:39
  Speaker 1: a fungus, wiped out large amounts of big mics, most
• 33:42
  Speaker 1: markets switched over to the Cavendish. The worry now is
• 33:44
  Speaker 1: that the Cavendish may be affected in the same way soon.
• 33:47
  Speaker 1: UM Mono cultures aren't the best plan, apparently, So essentially,
• 33:52
  Speaker 1: the bananas that we eat now that we know and love,
• 33:55
  Speaker 1: the banana flavoring that they use is not based on
• 33:58
  Speaker 1: those bananas, and that's why it taste weird. Um. That's
• 34:02
  Speaker 1: pretty interesting and a lot of people send this in
• 34:05
  Speaker 1: so I tend to believe it because if like four
• 34:07
  Speaker 1: people say something, yeah, it's definitely right. Uh. And here's
• 34:10
  Speaker 1: an extra factory, he says. Cherry flavor is based on
• 34:13
  Speaker 1: Maraschino cherries, which is which are in turn flavored with
• 34:16
  Speaker 1: almond extracts. So cherry flavored candy is somewhat almond flavored.
• 34:21
  Speaker 1: And thanks for the great show. I look forward to
• 34:23
  Speaker 1: every episode. And that is from Elliott. Thanks Elliott, good
• 34:26
  Speaker 1: stuff there, Cavendish Big Mica had no idea. Yeah, and
• 34:30
  Speaker 1: like bananas are all a sexual, so every banana that
• 34:33
  Speaker 1: you've ever had is an exact clone of its pro
• 34:37
  Speaker 1: janitor crazy and that I'm gonna watch that Don't Be
• 34:39
  Speaker 1: Dumb episode. Let's do it right now. Yeah, Okay, if
• 34:44
  Speaker 1: you want to check out Don't Be Dumb, you can
• 34:46
  Speaker 1: go to our website, but first you should get in
• 34:49
  Speaker 1: touch with us via s Y s K podcast on Twitter,
• 34:52
  Speaker 1: at our Facebook dot com slash stuff you Should Know page.
• 34:55
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• 34:57
  Speaker 1: it to stuff podcast at how stuff first dot com
• 35:00
  Speaker 1: um and you can check out all of our videos,
• 35:02
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• 35:04
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• 35:07
  Speaker 1: the clubhouse known as stuff you dot com. For more
• 35:15
  Speaker 1: on this and thousands of other topics, is It How
• 35:17
  Speaker 1: stuff Works dot com.