Jenna

idk my bff Colin Meloy?

Fri, 25 Sep 2009 15:58:28 GMT

Me as a grocery-store-frequenting-UVa-color-representing superhero!

Sun, 08 Mar 2009 02:58:25 GMT

I'm alive!

Tue, 16 Dec 2008 22:50:32 GMT

So the last time I posted here was in October. I just wanted to let people know I'm still reading your journals and commenting occasionally, and now that I'm on Christmas break, maybe I'll actually start trying to update more than once every two months!

This semester was challenging, but it's finally over and I've come out mostly intact. My first chemical engineering class (Material and Energy Balances) started out rough, but got much better as the semester progressed. Differential equations was awesome, by far the most interesting math class I've taken. Physics was interesting and taught well by my particular teacher, but the department head is out to get everyone because of a cheating incident that happened last semester, so he made tests unreasonably difficult (he writes them), etc. etc. Our averages in there were usually around a 50 or 52%, which is set at a B, so I think I'm fine. Biotechnology (my other chemical engineering class) was taught by a new teacher who still hasn't mastered English yet (he's Korean), which wasn't too much of a problem since he had good lecture slides, but he wasn't the best of teachers. The material was pretty interesting, though. Microeconomics was great! It was definitely a nice contrast to all my engineering classes, and I will be taking macroeconomics next semester. I also joined some more clubs (Queer and Allied Activism, Queer Student Union, American Institute of Chemical Engineers, and got a leadership position in Society of Women Engineers!) and was far more social than during first year. Overall, I would call this semester a success!

So I have twelve days at home in Lynchburg, and then on the 29th I'm off to Guatemala for my January Term class. We have to perform an independent research project for it, so I am doing mine about AIDS and HIV in Guatemala, which I'm very excited about! Hopefully I'll be able to interview doctors and people with AIDS and HIV while I'm in Guatemala for my paper. We're also visiting the Mayan ruins, picking coffee beans on a coffee plantation, camping out in the jungle one night, shopping for local goods in street markets, taking a boat ride across Lake Atitlán, and much more that I will more than likely expand upon later. And apparently if we go to drink in a bar, you aren't supposed to argue about politics with the locals. Bad things will happen. Oh, and hopefully I won't be absorbed into any slave markets. That would put a damper on things.

Then I get back to the States on the 12th and classes start on the 13th (that timing should be fun!). Next semester I will be taking APMA 311 (Probability and Statistics), CHE 212 (Organic Chemistry and lab), CHE 202 (Thermodynamics), CHE 216 (Modeling and Simulations in Chemical Engineering), and ECON 202 (Principles of Macroeconomics), which is a total of 16 credits (one less than this semester!). I'm definitely looking forward to more chemical engineering classes, and this will be the last math class I'll ever have to take--weird.

Oh, and I've been getting calls from government people doing background checks on me for an internship with BWX-T (a nuclear engineering company in Lynchburg) for the summer, so hopefully that means they're taking my application seriously! I'll hopefully hear back about it any day now. *fingers crossed*

Wed, 08 Oct 2008 04:50:48 GMT

I'm going to Guatemala for UVa's J-Term (from December 29th to January 11th)! I will be taking a class on the "Natural and Built Environment and Public Health of Guatemala." So basically it's about how engineering and medicine can interact to solve problems in an international setting. I'm so excited! Hooray!

Ha ha ha ha

Sun, 05 Oct 2008 02:55:15 GMT

Tue, 16 Sep 2008 04:36:04 GMT

It seems that the more work I get, the less loquacious I get, at least on LiveJournal. I offer you a brief update. And by brief update, I mean a list of my classes.

PHYS 241E - Physics: Electricity and Magnetism
PHYS 241W - Lab
CHE 215 - Material and Energy Balances
CHE 246 - Introduction to Biotechnology
APMA 213 - Ordinary Differential Equations
ECON 201 - Principles of Microeconomics

I actually like all the classes, even though one of my major's classes (CHE 215) is a bit odd since we're doing stuff I've never been exposed to before. I guess odd is better than impossible.

Oh yeah, and science rules.

Most memorable quote from this trip

Sun, 27 Jul 2008 23:16:56 GMT

Grandma: Do you practice frottage?

Thu, 24 Jul 2008 02:33:13 GMT

So here I am, sitting in my grandparents' kitchen in Port Townsend, WA, watching Jeopardy and updating my LiveJournal. For dinner tonight was quinoa, broccoli, cheese, and onion casserole with baked sweet potatoes made by yours truly. Mission success. Tomorrow will involve bookstores and guacamole. Life is good.

My first LOLcat!

Thu, 10 Jul 2008 02:33:25 GMT

W3D3

Sat, 14 Jun 2008 18:48:01 GMT

I just completed week 3 day 3 of my running plan! I ran 2400 yards (~1.36 mi) in 18 minutes. I ran on the treadmill at a 2.0% incline, which is unfortunate because I do want to try running outside at some point in this program (today would not have been a good first day as it is 90°F outside). Overall I'm proud of myself at this point and can't wait to get onto week 4!

Thu, 12 Jun 2008 21:17:17 GMT

I got pictures of the nest in our garage!

Here birdy birdy

Tue, 10 Jun 2008 21:48:45 GMT

My dad recently told my mom and me that there is a bird's nest in one of his small storage bins in his garage (it looks something like this, but with a covering on top as well). After looking inside the nest, we discovered there were two tiny eggs inside, no bigger than a miniature-sized Cadbury egg! And we (my mom and I) were lucky enough to see the mother or father bird (whichever one takes care of the eggs--I'm not sure) fly out of the garage the other day. I don't know what type of bird it is exactly, but I'm doing some research on Virginian birds and it's color resembles that of a purple finch, but it seems a bit too big to be the bird we saw. It's body size resembles that of a warbler or wren more. That's the best I can do at this point, but if I can, I'll try to get pictures of the nest if the mom/dad (m/d...haha) is away. It's pretty neat how m/d has it set up--there are still various hooks and nails and screws in the front of the storage bin, but nestled in the back is m/d's nest and it looks as comfy as can be.

6 Random Things Meme

Tue, 10 Jun 2008 18:56:28 GMT

The Rules:

1. Link to the person who tagged you. (The fabulous antarcticlust)
2. Post the rules on your blog.
3. Write six random things about yourself.
4. Tag six random people at the end of your post by linking to their blogs.

1. When I think of the alphabet, numbers or ages of people, or the time of day, I imagine them from left to right; when I think of the days of the week, I imagine them from top to bottom, with Sunday at the top and Saturday at the bottom. I think this last one stems from a poster my kindergarten teacher had in the classroom.

2. Half of my face doesn't produce pigment and so I have white blotchy skin, white eyelashes, one white eyebrow, and half a head of white hair on 50% of my head, although I dye my hair and eyebrow black so it doesn't show up.

3. I have two decorative decals on my car--one on the upper left hand corner of my rear window that is a V for UVa and inside the V it says "ENGINEERING." The other is a red Tool decal on the bottom middle of my rear window.

4. I store my books in four places--my main bookshelf by my bedside table, another bookshelf in my closet, and two drawers of my dresser and one drawer of my bedside table. I know, I know, I need help.

5. I have two necessary pieces of jewelry I must wear everyday (besides those reserved for my piercings)--my watch (a pink and black Timex I've had since 10th grade that I wear on my left wrist) and my high school class ring (one with an onyx stone, JENNA engraved on one side and 2007 on the other, with my school colors, which are maroon and gold, on each side, and music and track symbols engraved on the sides, and I always wear it on my left ring finger). I've worn these two pieces so much I have tan lines around them.

6. I've never had braces, cavities, and have not had my two (and only two--yes) wisdom teeth pulled yet and I have good teeth. That's one thing I've been truly lucky about.

And now I tag...
blueyoshi22
cidthecoatrack
foolish_m0rtal
gutzilla
jackshoegazer
opiumcat

The Neuroscience of Illusion

Wed, 28 May 2008 19:29:40 GMT

How tricking the eye reveals the inner workings of the brain

By Susana Martinez-Conde and Stephen L. Macknik

The Neural Correlate Society recently announced the winners of its annual Best Visual Illusion contest. To celebrate the event, Mind Matters invited Susana Martinez-Conde and Stephen L. Macknik, two neuroscientists who specialize in visual perception, to explain the scientific value of visual illusions. This article is the first in a new Mind Matters series on the neuroscience of illusions.

It’s a fact of neuroscience that everything we experience is actually a figment of our imagination. Although our sensations feel accurate and truthful, they do not necessarily reproduce the physical reality of the outside world. Of course, many experiences in daily life reflect the physical stimuli that enter the brain. But the same neural machinery that interprets actual sensory inputs is also responsible for our dreams, delusions and failings of memory. In other words, the real and the imagined share a physical source in the brain. So take a lesson from Socrates: “All I know is that I know nothing.”

One of the most important tools used by neuroscientists to understand how the brain creates its sense of reality is the visual illusion. Historically, visual artists as well as illusionists have used visual illusions to develop deep insights into the inner workings of the visual system. Long before scientists were studying the properties of neurons, artists had devised a series of techniques to “trick” the brain into thinking that a flat canvas was three-dimensional, or that a series of brushstrokes was actually a still life.

Visual illusions are defined by the dissociation between the physical reality and the subjective perception of an object or event. When we experience a visual illusion, we may see something that is not there, or fail to see something that is there, or even see something different from what is there. Because of this disconnect between perception and reality, visual illusions demonstrate the ways in which the brain can fail to recreate the physical world. By studying these failings, we can learn about the computational methods used by the brain to construct visual experience.

In the accompanying slide show, we will showcase several basic categories of visual illusions and what they can teach us about the brain.

View a slide show of illusions

By the way, I did my second workout for Couch-to-5K today. I'm feelin' fine!

My first post in eons, inspired by antarcticlust

Wed, 28 May 2008 01:32:06 GMT

As mentioned above, Jacquelyn gets props for me writing this. A while ago, she posted an entry about the Couch-to-5K running plan. I must have started and stopped this program three times by now, not because it's ineffective or super-challenging, but because I didn't have the motivation or stamina to stick with it. Hopefully with some recent lifestyle changes (I've become a vegetarian again and am conscious of what I put into my body now more so than ever) and a big support group (such as my LJ friends, plus my dad is doing the running plan with me!) I will have more will power in sticking with this. I would ideally love to get down to 140 lbs for my 5'7" frame, but this is a very long-term goal. I've come to realize the power of realistic, short-term goals, so I'm not trying to think of my ultimate goal at this point. My goal at the moment is to stick with this workout routine and to drink 1.5 L of water and take one multivitamin per day (which I have been good about!).

By the way, this episode of Naked Science about the Phoenix mission is pretty sweet.

Same barbers?

Tue, 29 Apr 2008 19:01:46 GMT

Sat, 22 Mar 2008 18:31:34 GMT

My friends, it is 72°F outside right now.

You guys rock!

Wed, 13 Feb 2008 04:55:11 GMT

Movie Quote Meme!

Here is how it works:
1. Pick 15 of your favorite movies.
2. Go to IMDB and find a quote from each movie.
3. Post them here for everyone to guess.
4. Strike it out when someone guesses correctly, and put who guessed it and the movie.
5. NO GOOGLING/using IMDB search functions. Totally cheating, you dirty cheaters.

1) ~~Whatcha got ain't nothin new. This country's hard on people, you can't stop what's coming, it ain't all waiting on you. That's vanity.~~ No Country For Old Men antarcticlust, gutzilla

2) ~~Normally, both your asses would be dead as fucking fried chicken, but you happen to pull this shit while I'm in a transitional period so I don't wanna kill you, I wanna help you.~~ Pulp Fictionjackshoegazer, gyttja, gutzilla

3) ~~A mental mindfuck can be nice.~~ Rocky Horror Picture Show gyttja

4) ~~I'm only allowed to let in five percent black people. He said that, that means if there's 25 people here I get to let in one and a quarter black people. So I gotta hope there's a midget in the crowd.~~ Knocked Up mmmrorschach

5) ~~Read Marcus Aurelius. Of each particular thing ask: what is it in itself? What is its nature? What does he do, this man you seek?~~ Silence of the Lambs antarcticlust

6) Mostly I'm tired of people being ugly to each other. I'm tired of all the pain I feel and hear in the world everyday. There's too much of it. It's like pieces of glass in my head all the time. Can you understand? The Green Mile opiumcat

7) ~~I'm voting for Dukakis.~~ Donnie Darko freckled_tiger, gutzilla

8) ~~There has to be a mathematical explanation for how bad that tie is.~~ A Beautiful Mind antarcticlust

9) What have I got Harry, hm? Why should I even make the bed, or wash the dishes? I do them, but why should I? I'm alone. Your father's gone, you're gone. I got no one to care for. What have I got, Harry? I'm lonely. I'm old. Requiem For a Dream opiumcat

10) ~~Bottom line is... we're around each other an'... this thing, it grabs hold of us again... at the wrong place... at the wrong time... and we're dead.~~ Brokeback Mountain gyttja, cidthecoatrack, gutzilla

11) ~~How is it possible to feel nostalgia for a world I never knew?~~ The Motorcycle Diaries opiumcat

12) New lovers are nervous and tender, but smash everything. For the heart is an organ of fire.

13) ~~Now, a question of etiquette - as I pass, do I give you the ass or the crotch?~~ Fight Club jackshoegazer

14) ~~A real loser is someone who's so afraid of not winning he doesn't even try.~~ Little Miss Sunshine antarcticlust

15) ~~As the sound of the playgrounds faded, the despair set in. Very odd, what happens in a world without children's voices.~~ Children of Men antarcticlust

Clinton, Obama, Insurance

Tue, 05 Feb 2008 22:56:00 GMT

By PAUL KRUGMAN
Published: February 4, 2008

The principal policy division between Hillary Clinton and Barack Obama involves health care. It’s a division that can seem technical and obscure — and I’ve read many assertions that only the most wonkish care about the fine print of their proposals.

But as I’ve tried to explain in previous columns, there really is a big difference between the candidates’ approaches. And new research, just released, confirms what I’ve been saying: the difference between the plans could well be the difference between achieving universal health coverage — a key progressive goal — and falling far short.

Specifically, new estimates say that a plan resembling Mrs. Clinton’s would cover almost twice as many of those now uninsured as a plan resembling Mr. Obama’s — at only slightly higher cost.

Let’s talk about how the plans compare.

Both plans require that private insurers offer policies to everyone, regardless of medical history. Both also allow people to buy into government-offered insurance instead.

And both plans seek to make insurance affordable to lower-income Americans. The Clinton plan is, however, more explicit about affordability, promising to limit insurance costs as a percentage of family income. And it also seems to include more funds for subsidies.

But the big difference is mandates: the Clinton plan requires that everyone have insurance; the Obama plan doesn’t.

Mr. Obama claims that people will buy insurance if it becomes affordable. Unfortunately, the evidence says otherwise.

After all, we already have programs that make health insurance free or very cheap to many low-income Americans, without requiring that they sign up. And many of those eligible fail, for whatever reason, to enroll.

An Obama-type plan would also face the problem of healthy people who decide to take their chances or don’t sign up until they develop medical problems, thereby raising premiums for everyone else. Mr. Obama, contradicting his earlier assertions that affordability is the only bar to coverage, is now talking about penalizing those who delay signing up — but it’s not clear how this would work.

So the Obama plan would leave more people uninsured than the Clinton plan. How big is the difference?

To answer this question you need to make a detailed analysis of health care decisions. That’s what Jonathan Gruber of M.I.T., one of America’s leading health care economists, does in a new paper.

Mr. Gruber finds that a plan without mandates, broadly resembling the Obama plan, would cover 23 million of those currently uninsured, at a taxpayer cost of $102 billion per year. An otherwise identical plan with mandates would cover 45 million of the uninsured — essentially everyone — at a taxpayer cost of $124 billion. Over all, the Obama-type plan would cost $4,400 per newly insured person, the Clinton-type plan only $2,700.

That doesn’t look like a trivial difference to me. One plan achieves more or less universal coverage; the other, although it costs more than 80 percent as much, covers only about half of those currently uninsured.

As with any economic analysis, Mr. Gruber’s results are only as good as his model. But they’re consistent with the results of other analyses, such as a 2003 study, commissioned by the Robert Wood Johnson Foundation, that compared health reform plans and found that mandates made a big difference both to success in covering the uninsured and to cost-effectiveness.

And that’s why many health care experts like Mr. Gruber strongly support mandates.

Now, some might argue that none of this matters, because the legislation presidents actually manage to get enacted often bears little resemblance to their campaign proposals. And there is, indeed, no guarantee that Mrs. Clinton would, if elected, be able to pass anything like her current health care plan.

But while it’s easy to see how the Clinton plan could end up being eviscerated, it’s hard to see how the hole in the Obama plan can be repaired. Why? Because Mr. Obama’s campaigning on the health care issue has sabotaged his own prospects.

You see, the Obama campaign has demonized the idea of mandates — most recently in a scare-tactics mailer sent to voters that bears a striking resemblance to the “Harry and Louise” ads run by the insurance lobby in 1993, ads that helped undermine our last chance at getting universal health care.

If Mr. Obama gets to the White House and tries to achieve universal coverage, he’ll find that it can’t be done without mandates — but if he tries to institute mandates, the enemies of reform will use his own words against him.

If you combine the economic analysis with these political realities, here’s what I think it says: If Mrs. Clinton gets the Democratic nomination, there is some chance — nobody knows how big — that we’ll get universal health care in the next administration. If Mr. Obama gets the nomination, it just won’t happen.

So I won't be sleeping tonight....

Sun, 03 Feb 2008 05:04:44 GMT

Photo Meme!

Tue, 29 Jan 2008 18:03:17 GMT

Request a photo (or photos) of something in my life that you'd like to see, and I'll show the photos in a later post. This includes anything--my life at UVa, my home in Evington, VA, or anywhere in between!

Yay Java!

Tue, 29 Jan 2008 01:39:20 GMT

You can input whatever values you want for the first part, so I put in 3000 songs, 180 minutes of video, 1000 photos, and a 7.5 mega pixel camera resolution.

$300 to Learn Risk of Prostate Cancer

Thu, 17 Jan 2008 13:06:35 GMT

By GINA KOLATA
Published: January 17, 2008

A combination of common and minor variations in five regions of DNA can help predict a man’s risk of getting prostate cancer, researchers reported Wednesday.

A company formed by researchers at Wake Forest University School of Medicine is expected to make the test available in a few months, said Karen Richardson, a Wake Forest spokeswoman. It should cost less than $300.

This is, some medical experts say, a first taste of what is expected to be a revolution in medical prognostication. The results, they agree, are clear. But the question is what happens next. And will patients be helped or harmed? Because the new test — which will analyze DNA in blood or saliva samples and is to be offered by ProActive Genetics — cannot predict which men will get aggressive cancers, it could lead to more screening and unnecessary surgery and complications. But, proponents say, it could also help men decide whether they want aggressive screening in the first place.

The researchers found that about 90 percent of the men in the study had one or more of the gene variants and more than half had two or more. The cancer risk increased as the number of variants rose and increased substantially when men had four or five of the variants.

Men with four or five variants made up only 2 percent of the study population but had a 4.5-fold increased risk of having prostate cancer compared with men who had none of the variants. If the men also had a family history of prostate cancer, their risk was nearly 10 times higher than that of men with none of those risk factors. Less than 1 percent of the population had all the variants and a family history.

The researchers report that nearly half of the cases of prostate cancer among the roughly 5,000 men in the study could be attributed to the five gene regions and a family history, with some men having one or two of the gene variants and others having all five and a family history.

Prostate cancer becomes more common as men age — autopsies of elderly men find that most had prostate cancer, whether they knew it or not. But the men in this study had an average age of about 65, when the disease is less common and more likely to kill.

William B. Isaacs, a professor of urology and oncology at Johns Hopkins University and an author of the new report, said that if research validates what has been found, men may want to get the new genetic test when they are young, 35, say. Those at high risk because of their genetics might then choose to start prostate-cancer screening earlier than the usual age of about 50, using a blood test that looks for proteins secreted by prostate tumors.

“I think that makes sense,” said Dr. Howard Sandler, a professor of radiation oncology at the University of Michigan and a spokesman for the American Society of Clinical Oncology.

But others worry that more frequent testing could exacerbate what is already a major problem: most prostate cancers grow so slowly that they would have been harmless if left alone. But since doctors cannot tell which are dangerous, they treat nearly all that they find. And treatment has serious side effects, including, often, impotence and incontinence. Nonetheless, researchers say, the test is a harbinger of things to come.

“It’s the boutique medicine of the future,” said Dr. Peter C. Albertsen, a surgery professor and prostate cancer specialist at the University of Connecticut. “We can know what diseases we will have to face in the rest of our lives.”

That worries him, as it does Dr. Edward P. Gelmann, deputy director of the Comprehensive Cancer Center at Columbia University. “Technology today enables us to find out a huge amount of information,” Dr. Gelmann said. “But how does the public deal with this information? How does it help them make decisions? And if they make a decision, does that lead to a day, a week, a month, of life saved?”

The study, by scientists at Wake Forest University School of Medicine, the Karolinska Institute in Sweden, the Harvard School of Public Health, and Johns Hopkins Medical Institutions, will appear in the Jan. 31 issue of The New England Journal of Medicine. It was released online on Wednesday, a journal spokeswoman said, because “it is a very active area of research with a lot of competition.”

Researchers long knew that the disease often runs in families. Though scientists spent years looking for genes, they found none that were reproducibly associated with a marked effect.

With new technology to scan the entire length of a person’s DNA, researchers tried a new approach. They began looking for small variations in tiny DNA regions that were associated with prostate cancer. That resulted in the discovery, by several groups of investigators in Iceland and the United States, of the gene variants, small alterations in gene sequences. Unlike traditional genetic links to disease, the variants are not mutations that destroy a gene’s function. In fact, no one knows what their effect is.

The next step was to ask whether those variants really could predict who had prostate cancer. So Dr. Jianfeng Xu, a professor of epidemiology and cancer biology at Wake Forest University School of Medicine, and his colleagues studied a Swedish population of 2,893 men with prostate cancer and 1,781 men who did not have it. That led to their finding that each of the five variants independently predicted prostate cancer risk.

“Each confers a moderate risk,” Dr. Xu said, adding that the effect of having just one of the variants — a 10 or 20 percent increase in a man’s chance of having prostate cancer — was not enough to justify using a single variant for screening. But, he added, because each conferred an independent risk, the risks added up so that the more men had, the greater their risk. Then they found that family history of the cancer added an independent risk. “That was very, very surprising to us,” Dr. Xu said.

The next step, Dr. Isaacs said, is to look in other populations. “We think that can happen almost instantaneously,” he said, explaining how scientists have blood samples and family histories of thousands of men who were tested for prostate cancer.

But some said that if the test leads to more screening, it is not necessarily a good thing. There is already too much prostate-cancer screening, they say, resulting in too much treatment. “To me, it is a nightmare,” Dr. Albertsen said. “We are just feeding off of this cancer phobia.”

What is needed, and what the new test does not provide, is a way to decide which cancers are dangerous and which are not, Dr. Isaacs said. Still, he said the new test could help patients if it was used with caution. “We may be premature with this idea — everyone has a different way of thinking about this — but it should not take five years to know if we are on the right track. All this can happen very rapidly.”

“We have worked with enough families that have a positive family history to know that people are anxious to know their risk of prostate cancer,” he said.

Researchers Create New Rat Heart in Lab

Mon, 14 Jan 2008 00:29:56 GMT

By LAWRENCE K. ALTMAN
Published: January 13, 2008

Medicine’s dream of growing new human hearts and other organs to repair or replace damaged ones received a significant boost on Sunday when University of Minnesota researchers reported success in creating a beating rat heart in a laboratory.

Experts not involved in the Minnesota work called it “a landmark achievement” and “a stunning” advance. But they and the Minnesota researchers cautioned that the dream, if it is ever realized, is still at least 10 years away.

Dr. Doris A. Taylor, the head of the team that created the rat heart, said that she followed a guiding principle of her laboratory — “give nature the tools and get out of the way.”

“We just took nature’s own building blocks to build a new organ,” Dr. Taylor said of her team’s report in the journal, Nature Medicine.

The researchers removed all the cells from a dead rat heart, leaving the valves and outer structure as scaffolding for new heart cells injected from newborn rats. Within two weeks, the new cells formed a new beating heart that conducted electrical impulses and pumped a small amount of blood.

With modifications, scientists should be able to grow a new human heart by taking stem cells from a patient’s bone marrow and placing them in a cadaver heart that’s been prepared as a scaffold, Dr. Taylor said in a telephone interview from her laboratory in Minneapolis. The early success “opens the door to this notion that you can make any organ: kidney, liver, lung, pancreas — you name it and we hope we can make it,” she said.

“Doris Taylor’s work is one of those maddeningly simple ideas that you knock yourself on the head, saying why didn’t I think of that,” said Todd N. McAllister, of Cytograft Tissue Engineering of Novato, Calif. His team has used a snippet of a patient’s skin to grow blood vessels in a laboratory and then implanted them to restore blood flow around a patient’s damaged arteries and veins.

The field of tissue engineering has been growing rapidly. For many years, doctors have used engineered skin for burn patients. Engineered cartilage is used for joint repairs. Researchers are investigating use of stem cells to repair cardiac muscle damaged by heart attacks. Also, new bladders grown from a patient’s own cells are being tested in the same patients.

Dr. Taylor is a newcomer to tissue regeneration. She began her professional career at the Albert Einstein Medical School in the Bronx investigating gene therapy and then cell therapy. She said she switched to tissue regeneration when she realized the limiting step in trying to generate an organ was not the number of cells needed, but the complexity of creating a three-dimensional structure.

“The heart is a beautiful organ, and it’s not one that I thought I’d ever be able to build in a dish,” Dr. Taylor said.

Her view changed about three years ago when she recalled that cells are removed from human and pig heart valves before they are used to replace damaged human ones. As she contemplated replacing the old rat cells with new ones, Dr. Taylor followed another of her mantras: “trust your crazy ideas.”

Progress came in fits and starts. “We made every mistake known, did every experiment wrong and had to go back and do them right,” Dr. Taylor said.

She poured detergents like those in shampoos in the rat’s arteries to wash out the heart cells and then injected neonatal cardiac cells. The first two detergents she tested failed. But a third concoction led to a clear, translucent scaffold that retained the heart’s architecture.

After injecting the young rat heart cells into a scaffold, she stimulated them electrically and created an artificial circulation as the equivalent of blood pressure to make the heart pump and produce a pulse. The steps also helped the cells mature. Tests like examining slices of the heart under a microscope showed they were living cells.

To test the biological compatibility of the new hearts, the team transplanted them into the abdomen of unrelated live rats. The hearts were not immediately rejected. A blood supply developed. The hearts beat regularly. And cells from the host rats moved in and began to re-line the blood vessels, even growing in the wall of the hearts.

Dr. Taylor is now conducting similar experiments on pigs as a step toward human work. “Working out the details in a pig heart made a lot more sense” because the anatomy of the porcine heart is the closest to humans and pigs are plentiful, she said.

“The next goal will be to see if we can get the heart to pump strongly enough and become mature enough that we can use it to keep an animal alive” in a replacement transplant, Dr. Taylor said.

As for human hearts, the best-case scenario would be to obtain them from cadavers, remove their cells to make a scaffold and then inject bone marrow, muscle or young cardiac cells from a patient. The process of repopulating the scaffold with new cells would take a few months, she said.

The body continually replaces its proteins every few months, so the hope is that the body will create a matrix that it recognizes as its own.

One potential problem is that anti-rejection drugs might be required to prevent adverse immune reactions from the scaffold. In that case, Dr. Taylor hopes such therapy would be needed only temporarily.

Many things that work in experiments on animals fail in humans because of the species barrier. Dr. McAllister said that in Dr. Taylor’s case “the principal problem in escalating it to humans is one of scale, not of cell biology, and that is an easier problem to solve potentially.”

“If it works, it means that there’ll be many more organs available for transplants,” Dr. Taylor said.

Because the components of the biologic matrix differ for every organ, Dr. Taylor expects that scientists will be able to do tests to answer two fundamental questions: Can a stem cell be placed anywhere in the body and still produce a heart, kidney or other organ? Or must a stem cell be placed in its anatomic position to do so?

Such tests might include taking stem cells from one organ, say a kidney, and putting them in a kidney, liver or heart to begin to understand if the stem cells are innately committed to produce kidneys or whether they will convert to produce livers or hearts.

Tue, 25 Dec 2007 16:16:38 GMT