Stories tagged Cells

Sep
15
2008

Makes me wonder...: Where were you on the night of the incident?
Makes me wonder...: Where were you on the night of the incident?Courtesy kalimistuk
A French dog, nicknamed “Scooby,” may be the first animal in the history of animals to be used as a witness in a murder trial.

Scooby, whose real name (I’m guessing) is being withheld for his own safety, is believed to have been present when his 59-year old owner was hung from the ceiling of her Paris apartment.

The death was initially supposed to be a suicide, but the dead woman’s family demanded a murder investigation. During the preliminary trial, the dog was lead to the witness box to see how it reacted to a suspect. Scooby is reported to have started “barking furiously” as he neared the suspect.

The judge has yet to decide whether there’s enough evidence to launch a full murder inquiry, but was very impressed with Scooby.

In addition to the outburst at the witness, however, several crotches and one butt have been added to the list of suspects.

Soooo… How can this be a science story? Well, let us consider the olfactory prowess of your average dog, and how that could possibly be considered as evidence in a case that would put a person in jail for, no doubt, a long, long time.

I don’t know if you live in an area where skulls—preferably mammal skulls—are readily available. If you do have a local skull store or skull pit, however, do yourself a favor and grab a skull or two. If you check out the nose hole (don’t use that term on any skull-themed tests, by the way), you’ll see a bunch of thin, bony, scroll-shaped plates. Air passing through the nose hole (again…) is spread out over the surface of these plates. The chemicals that give inhaled air its odor are dissolved into the mucus produced by the spongy tissue covering the plates. The chemicals (or odors) in the mucus are then detected by little antlered nerve cells (keep that one off the test too). These nerve cells run pretty much directly to the brain, where the detected chemicals are analyzed. The brain can then decide if you’ve just smelled triple berry pie, or, say, a French murderer.

Now, while I know of several individuals I could probably identify by smell, I’m pretty certain that I couldn’t pull your average French murderer out of a lineup by odor alone. But, then, I’m no dog.

The area of tissue covered with smell receptors in a human’s nose slightly less than a couple square inches—about the size of a big postage stamp. A dog, on the other hand, has enough smell receptors to cover an area of tissue almost as big as a standard sheet of printer paper. And while all dogs are significantly better smellers than humans (that is to say, better at receiving smells, not giving off pleasant ones), certain breeds of dog far outstrip the rest. A human, for instance, has about five million smell receptors. A wiener dog has about one hundred and twenty five million smell receptors, and a German shepherd has two hundred and twenty five million. Bloodhounds have about 300 million smell receptors. What’s more, the percentage of a dog’s brain devoted to analyzing smells is 40 times larger than the same area in a human’s brain. All things considered, it is thought that dogs are perhaps ten thousand times more sensitive smellers than humans. (Or, if you go by Wikipedia, a dog’s sense of smell is as much as one hundred million times more sensitive than a person’s. But I’d keep that off the test too.) Add all this to the notion that individuals may have unique individual odors, and it makes sense that a dog might be able to identify a person who had murdered their companion/owner.

Then again, I’m not sure I’d want to leave something like that up to a dog.

Sep
09
2008

Okay, hold that pose: But we're going to want to try it without... without...  Forget it.
Okay, hold that pose: But we're going to want to try it without... without... Forget it.Courtesy NASA
And they didn’t just have sex; they actually reproduced, which turns out to be important for naked astronauts. But we’re getting ahead of ourselves, aren’t we?

No, we aren’t.

Tiny, naked astronauts were recently exposed to the vacuum environment, harsh temperatures, and dangerous radiation of space for a period of several days. The space travelers went into an almost entirely dormant state for the duration, slowing their metabolisms to .01% of their normal levels.

After they were brought back into the low-orbit space vessel, most of the astronauts were completely revived. (Some died. It was very sad.) Aside from enduring the vacuum of space, and the extreme temperatures outside of a space capsule, the astronauts’ ability to survive the radiation of space most surprised scientists. On the surface of earth, solar radiation (as you no doubt are aware) is strong enough to give us sunburn, and cause genetic damage to our skin cells (leading to skin cancer). The levels of radiation in space are 1,000 times higher, enough to sterilize an organism, yet the astronauts did fine with it, and were even able to successfully reproduce on their return to earth. Scientists hope to isolate whatever mechanism allowed the astronauts to repair the genetic damage they likely incurred while in space. Such research might be applied to radiation therapy techniques.

We salute you, tiny, naked challengers of the unknown.

Aug
09
2008

20 types of diseased cells produced via stem cells

Using the new induced pluripotent stem cell (iPS) technique, researchers from Harvard Stem Cell Institute produced a robust new collection of disease-specific stem cell lines. Having these disease-specific iPS cells will allow researchers to watch the development of diseases in petri dishes, outside of the patients. HSCI iPS Core will produce these disease-specific cell lines for use by scientists around the world.

The cell lines the researchers produced carry the genes or genetic components for 10 different diseases, including Parkinson’s Disease, Type I diabetes, Huntington’s Disease, Down Syndrome, a form of combined immunodeficiency (“Bubble Boy’s Disease”), Lesch-Nyhan syndrome, Gaucher’s Disease, and two forms of Muscular Dystrophy, among others. Havard Stem Cell Institute Spotlight

Read the research paper online

The work is described in a paper published in the online edition of the journal Cell. Click here to read the full text of the paper titled, Disease-Specific Induced Pluripotent Stem Cells.The chief researchers were George Q. Daley, associate director of the Stem Cell Program at Children's Hospital Boston, and Chad Cowan and Konrad Hochedlinger of Massachusetts General Hospital.

Learn more by listening to their press conference

Click hear to listen to an 08/06/08 press conference with George Daley and Doug Melton (who is also co-chairman of Harvard's new interfaculty Department of Stem Cell and Regenerative Biology).

Aug
07
2008

Broccoli: The Super Food
Broccoli: The Super FoodCourtesy FIR0002
New research coming out of Britain shows eating broccoli may reverse damage done by diabetes to heart and blood vessels. I’m always glad to hear anything new about the benefits of broccoli. Not that I have diabetes – I don’t. But broccoli is my favorite vegetable, and besides its potentially new vascular benefits, the leafy vegetable is high in fiber, full of vitamins C and K, and nutrients that have been found to reduce the risk of some cancers. A member of the cabbage family (Brassica), broccoli, along with other vegetables in the genus (including brussel sprouts, cauliflower, turnips, kohlrabi, and mustard seed) has been linked to the reduction of strokes and heart attacks.

Diabetes is a serious metabolic disorder resulting in abnormally high levels of blood sugar (hyperglycemia). The disease can affect nearly every part of the body, and left untreated can lead to blindness, kidney failure, nerve damage, and loss of limb. Diabetics have up to 5 times the risk of suffering from vascular diseases such as heart attacks, strokes because of damaged blood vessels.

The current research involves the anti-cancer compound sulforaphane, a product of another compound found in broccoli called glucoraphanin. Sulforaphane encourages production of enzymes that protect blood vessels, and reduce levels of cell-damaging molecules. When researchers at the University of Warwick tested the effects of sulforaphane on blood vessels damaged by hyperglycemia (high sugar levels), they noticed a nearly 75% reduction of Reactive Oxygen Species (ROS) molecules in the body. High levels of ROS -the result of increased blood sugar- can damage cells. The researchers noted sulforaphane also protected cells by triggering a protein that activated antioxidant enzymes.

“Our study suggests that compounds such as sulforaphane from broccoli may help counter processes linked to the development of vascular disease in diabetes,” said Professor Paul Thornalley of the University of Warwick. His team’s appears in the journal Diabetes. Thornalley added that he expects future tests of a brassica vegetable-rich diet could yield further health benefits for diabetic patients.

"It is encouraging to see that Professor Thornalley and his team have identified a potentially important substance that may protect and repair blood vessels from the damaging effects of diabetes,” said Dr Iain Frame, director of research at the charity Diabetes UK. "It also may help add some scientific weight to the argument that eating broccoli is good for you."

That brings to mind the time when the first president Bush said since he was president he didn’t have to eat broccoli anymore. (I think the quote was “Read my lips: no more broccoli”) Well, good for him. It just means more of the natural, leafy panacea for the rest of us.

SOURCE and LINKS
BBC website story
American Diabetes Association
More on broccoli

Aug
02
2008

Stephan Hawking has ALS
Stephan Hawking has ALSCourtesy NASA

New hope for understanding Lou Gehrig's disease

Stephen Hawking has amyotrophic lateral sclerosis (ALS), a disease that destroys motor neurons. So far, progress in understanding this disease has been relatively slow, mainly because it has been difficult to obtain a decent supply of living motor neurons affected by the condition. New research done by John Dimos and Kit Rodolfa from the Harvard Stem Cell Institute has created in the laboratory a plentiful supply of cells that have the same genetic makeup as a patient with a particular disease.

Another stem cell breakthrough

A paper published online in the journal,Science, describes how they created the first stem cell lines from the skin of an elderly sick person, then coaxed these cells to become nerve cells genetically matched to those that had gone bad in a patient's spinal cord. By comparing diseased cells to normal cells in a Petri dish, scientists hope to better understand what causes disease and test new drugs.

This research builds upon the research we posted Jan. 18 titled Human embryo cloned from skin.

Learn more:

Jul
14
2008

Flu vaccine: This is CDC Clinic Chief Nurse Lee Ann Jean-Louis extracting Influenza Virus Vaccine, Fluzone® from a 5 ml. vial.
Flu vaccine: This is CDC Clinic Chief Nurse Lee Ann Jean-Louis extracting Influenza Virus Vaccine, Fluzone® from a 5 ml. vial.Courtesy CDC/Jim Gathany

Did you know back in February scientist and medical professionals selected the influenza virus strains for the upcoming flu season? Now that it is July the pharmaceutical companies are well into manufacturing, purification and testing the vaccine. Meanwhile, it is winter and flu season in the southern hemisphere and the virus is busy mutating. The big question on everyone’s mind is will it mutate so much that the northern hemisphere vaccine will be ineffective?
I agree with Dr. Steven Salzberg remarks in his recent Nature commentary

"The current system, in which most of the world’s vaccine supply is grown in chicken eggs, is an antiquated, inefficient method requiring six months or more to ramp up production, which in turn means that the vaccine strains must be chosen far in advance of each flu season. More crucially it sometimes prevents the use of the optimal strain, as it did in 2007."

Influenza (the flu) is a serious disease
Each year in the United States, on average:

  • 5% to 20% of the population gets the flu;
  • More than 200,000 people are hospitalized from flu complications, and;
  • About 36,000 people die from flu.

Some vaccine problems in the past
In recent years the match between the vaccine viruses and those identified during the flu season has usually been good. In 16 of the last 20 U.S. influenza seasons, including the 2007-08 season, the viruses in the influenza vaccine have been well matched to the predominant circulating viruses. Since 1988, there has only been one season (1997-98) when there was very low cross-reaction between the viruses in the vaccine and the predominate circulating virus and three seasons (1992-93, 2003-04, and 2007-08) when there was low cross-reaction (CDC). So after last year’s miscalculation the committee picked three new strains for the vaccine this year. One is a current southern hemisphere vaccine virus which they expect will still be present next year. In addition, they predict a second new Type A strain, known as H1N1/Brisbane/59, to also hit, along with a newer Type B/Florida strain.

Dr. Salzberg feels last year’s miscalculation was a failure…

"The harm was thus twofold; people fell ill and their trust in the vaccine system was undermined. This failure could have been predicted, if not prevented, through a more open system of vaccine design, a stronger culture of sharing in the influenza research community and a serious commitment to new technologies for production. The habits of the vaccine community must change for the sake of public health."

He goes on to suggest…

"The process of choosing flu-vaccine strains needs to be much more open. Other scientists, such as those in evolutionary biology with expertise in sequence analysis, could meaningfully contribute to the selection. At present, external scientists cannot review the data that went into the decision, nor can they suggest other types of data that might improve it."

Even with all of these miscalculations, I still feel getting the vaccine is worth the risk. But that doesn’t mean the process shouldn’t be improved. So once again I will be vaccinated and I will make sure my family is too—but what can we do as citizens to improve this process? What will you do?

Jul
13
2008

Signs of color preserved in stone?: Fossil feather from Brazil (left) displays similarities with recent woodpecker feather (right)
Signs of color preserved in stone?: Fossil feather from Brazil (left) displays similarities with recent woodpecker feather (right)Courtesy J.Vinther/Yale
Researchers at Yale University are reporting the discovery of pigmentation within the fossilize feather from a bird or dinosaur. Using a powerful electron microscope, paleobiologist Jakob Vinther and his team claim that particles seen in the 100-million-year-old fossil appear to be similar to those seen in the feathers of living birds. This could mean that color - a characteristic long-thought lost in the fossil record - could someday be determined from the remains of pigment.

Vinther’s colleagues included Yale paleontologist Derek E. G. Briggs and Yale ornithologist Richard O. Prum. The results of their study will appear in an upcoming issue of Biology Letters. The research shows that dark stripes in the Cretaceous-aged feather display many similarities to the make-up of black melanin particles found in modern bird feathers. Melanin compounds determine color in plants and animals, a trait useful for such things as camouflage, species identification, and courtship display. In humans, melanin colors our skin and also protects us from overexposure to sunlight.

For a long time, the dark granules seen in fossilized feathers were thought to be the carbon remains of bacteria that had worked at decomposing the organism prior to fossilization. But advances in electron microscope technology have given scientists a closer - and clearer – picture of the feather’s structure, and instead show them to be fossilized melanosomes containing melanin pigment.

"Feather melanin is responsible for rusty-red to jet-black colors and a regular ordering of melanin even produces glossy iridescence,” Vinther said. “Understanding these organic remains in fossil feathers also demonstrates that melanin can resist decay for millions of years."

Under the scope, the lighter bands of the fossilized feather showed only the rock matrix, while the darker bands displayed traces of residue closely resembling the organic compounds found in the feathers of modern birds.

“You wouldn’t expect bacteria to be aligned according to the orientation of the feathers,” said Vinther.

Another bird fossil showed similar organic traces in the feathers surrounding its skull. The 55-million-year-old fossil from Denmark also preserved an organic imprint of the eye that showed structures similar to the melanosomes found in eyes of modern birds.

Nanostructure studies could one day provide paleontologists with evidence of colors other than just black and gray tones, and not just in fossil feathers. Vinther figures other organic remains such as fur from prehistoric mammals or fossil skin impressions from dinosaurs could prove to be the remains of the melanin.

LINKS
ScienceNews story
Yale website story
Cosmos magazine website story
Melansome info

Jul
03
2008

Can you spot the nightmare?: There he is!
Can you spot the nightmare?: There he is!Courtesy FasterDix
Okay. Now I know what you’re thinking: “Every scene in Willow is frightening. Each scene is, in fact, somehow the most frightening scene. Will all of that become real too?”

Don’t worry, my doves, don’t worry.

You won’t be pursued through the forest by horrible pig dogs.

You won’t be puked on by a magic baby.

Your ethnicity won’t be slandered by drunks and soldiers.

You will not be captured and molested by hideous little rat men.

Monkeylike trolls will not chase you through derelict castles.

You won’t have to watch one of those awful trolls turn inside out and morph into a dragon. And you will not have to fight that dragon.

A shirtless Val Kilmer will not threaten you.

There will not be epic battles, nor attempted baby sacrifices.

You will not be stabbed by a man with a skull mask and an unspeakable caveman face.

A metal brazier will not chase you around a lightning-lit tower.

No wands will be brandished at you.

The town loudmouth will not belittle you in front of your family.

So, all in all, there’s relatively little to be concerned about. That said, there is one more most frightening scene to consider.

Do you remember when the army of Madmartigan and Airk Thaughbaer first laid siege to the fortress of Nockmark? Before Willow was able to fully control the powers of Cherlindrea’s wand and return Fin Raziel to her human, albeit greatly aged, form? You’ll recall that as soon as Airk, Madmartigan and Sorsha confront Bavmorda at the gates of Nockmark, the evil enchantress turns the whole of the attacking army into pigs. Once they were pigs things don’t seem so bad, but the process of turning into pigs was horrible to watch. There were hoof-hands everywhere, and emerging piggy snouts, and tusks, and oinking, and everybody looked really sweaty. It was very frightening to see, and it’s happening in our own plane of existence: human-pig hybrids have been given the go-ahead in England.

Careful examination of the story clearly indicates that half human, half pig creatures like those in Willow are neither the intent here, nor are they actually possible from these experiments. But I tend to believe what I imagine is the case more than what I’m old is the case.

If you do want to waste your time with what you’re told, however, listen up:
The aim of this research is in no way to create a weird pig man. Or a weird man pig. The goal is actually to put human DNA from skin cells into a pig egg that has had its chromosomes removed, and then let it develop into an embryo. In fact, the scientists involved are attempting to create an embryo with no animal DNA left in it at all (kind of ironic, I suppose).

There’s more to it, of course, but the idea is this: the human DNA put into the eggs will be DNA taken from people with a genetic heart disease. As the scientists observe the transformation from egg to embryo, they hope to better understand the molecular mechanics of the disease. That information could then be used to create better treatments for people living with related heart conditions. None of the “hybrids” will develop past the very first stages of being an embryo (basically a featureless sphere of cells).

Or, if you’re into letting your gut and imagination do your critical thinking for you…prepare yourself for Island of Doctor Moreau Earth.

Jun
25
2008

She's actually 60 years old: And look at her huge, weird head.
She's actually 60 years old: And look at her huge, weird head.Courtesy DistortedSmile
The more I learn about meditation, the more intrigued I am by it. I mean, meditation has it all: it can allow you to freeze yourself in a block of ice, walk across a bed of hot coals, and look like you’re asleep without actually being asleep (this is all according to what I learned from television, anyway).

Now there’s a new item, to add to the list of meditation-induced superhuman qualities: a huge, swollen brain. Isn’t that what you’ve always wanted? A rippling, throbbing, , Humungus, brain? Now’s your chance.

Researchers at Harvard have shown that regular meditation thickens your cortex. Generally the cortex thins as we age, but this area of gray matter, or, as some scientists call it, “thought goo,” seems to get thicker with age, at least in folks who meditate.

The study took a group of 20 experienced meditators, and compared their brain scans with those of 15 nonmeditators. During the brain scanning, meditators meditated, and nonmeditators “thought about whatever they wanted” (so, like, cigarettes, animals in clothing, detergent commercials, and clouds shaped like stuff. You know: stuff we normals enjoy).

All participants were adults, and came from a range of professions (except for 4 of the meditators, who actually were teachers of meditation or yoga).

The scans indicated that people who meditated an average of 40 minutes a day had gray matter of increased thickness, compared to the nonmeditators. What’s more, people who had been in the habit of meditating for a longer period of time had “the greatest changes in brain structure,” suggesting that meditation was the cause for the increase in gray matter, and not that people with thick gray matter are more inclined to meditate.

The increase in thickness, it should be said, only amounts to 4 to 8 thousandths of an inch—sadly not enough to make your brain bulletproof. The difference was consistent, however between people who meditated and those who did not, and further studies are planned to examine how this change might affect the health of a meditator.

Because meditation seems to counteract thinning of the brain over time, there’s some thought that the practice could slow—or reverse—the aging of the brain.

Monks and yogis, a researcher points out, suffer from the same ailments as they age as the rest of us, but they claim an increased capacity for attention and memory.

It’s still a toss up, as far as I’m concerned. Sure, monks may enjoy a lucid old-age, but that means they sacrificed tons of time meditating in their youth, when they could have been taking hard drugs and listening to rock and roll. I suppose it just depends on where your priorities are.

Jun
20
2008

For decades, scientists have been growing microbes in their labs and watching them evolve new traits. Most of the changes tend to be simple things, like an increase in size or growth rate.

But Dr. Richard Lenski of Michigan State University (just 2 miles from my house!) recently witnessed a major evolutionary leap--as it was happening. Twenty years ago, he took a colony of E. coli, a common bacteria, and split it into 12 identical populations. He’s been watching ever since to see if the strains evolve in different directions.

A few years ago, one of them did. One of his study strains suddenly evolved the ability to eat citrate, a molecule found in citrus fruits. No other E. coli in the world can do this, not even the other strains in Dr. Lenski’s lab. Even given several extra years and thousands of extra generations, the other strains are still citrate-averse. What’s more, the bacteria evolved this mutation entirely on their own, without any prodding or genetic manipulation from the researchers.

Lenski had saved frozen reference samples of all of his strains at regular intervals. Going back and growing new cultures from these samples, he again finds that only those from one strain ever evolve the citrate-eating habit – and only those sample less than about 10 years old. Lenski figures that some mutation happened around that time in one strain – and one strain only – that would later lead to citrate eating. He and his lab are now working on figuring out exactly what that mutation is.