Stressful Gut-feelings

In examing what exactly happens to the gut when experiencing stress, researches began placing lab rats in stressful situations, then proceeded give the rats water with and without the probiotic bacteria Lactobacillus helveticus and Lactobacillus rhamnosus. By placing rats on a small island, surrounded by water for one hour a day for several consecutive days, the psychological stress felt by humans was replicated and physical signs of stress could be tested. This water stress led to a vulnerability in the gut of rats which allowed harmful bacterial cells to adhere to the cells lining the gut wall. There were also signs that harmful bacteria had entered and activated the immune system, but when probiotic bacteria were entered into the rats there were much fewer cases of bacteria attaching to the gut wall or entering the immune system. Stress is known to cause several diseases, including irritable bowel syndrome, and has other negative effects on the body. By introducing probiotic, harmless bacteria into the body of someone suffering from chronic stress, they compete for space and cause less harmful bacteria to have an effect on the host. Though these studies do not directly help reduce stress, they can help to reduce the physical maladies associated with it.

Article: http://www.sciencedaily.com/releases/2006/04/060430002647.htm

Lose Yourself in Science

Losing yourself in a moment is something that we have all experienced. During strenuos or demanding situations, it is not unnatural for one to lose the ability to reason and instead rely on instinctual actions. Scientists Rafael Malach and Ilan Goldberg have taken a scientific approach to uncovering this phenomenon and have determined "that self-related function actually shuts down during such intense sensory tasks." This function of the brain therefore does not actively produce any clear sensory experiences. These findings help to understand the overall connection between consciousness and perception. Creating a system to test this function was not easy but developed a system to test sensory processing by showing the subject a series of pictures and having them listen to multiple musical pieces. The subjects were asked to indicate whether the pictures were either animal or non-animal, then if the musical pieces were trumpet or non-trumpet. This tested their ability to process senses, and their introspection was tested by asking the subjects how emotionally the pictures and sounds affected them. Brain activity was then measured by using magnetic resonance imaging which looked at what areas of the brain were getting the most blood flow. The imaging showed that certain areas were affected by sensory processing while other areas showed activity during introspection. These studies show that during intense perceptual engagement, the distracting self-related cortex becomes inactive and all blood flow is sent to the sensory cortex area of the brain, causing individuals to manage only that which immediately affects them.

Article: http://www.sciencedaily.com/releases/2006/04/060430004451.htm

Smoking is bad for you? No way!

Recent studies have shown that patients with lung cancer have a better chance of surviving and responding to chemotherapy if they have never smoked cigarettes before. Lung cancer is one of the most dangerous cancers and victims rarely live longer than five years after being diagnosed. Even if cured, there is a good chance that another tumor will appear. After being diagnosed with lung cancer, many patients continue to smoke because they believe it will not have an effect on their recovery. Up until recently, there has been no concrete evidence to prove them wrong, but recently Anne S. Tsao, M.D. of the University of Texas M. D. Anderson Cancer Center in Houston has looked over the records of over one thousand patients with non-small cell lung cancer and determined that patients who have never smoked before respond better to chemotherapy, had less disease progression while undergoing therapy, and displayed an overall greater survival rate. This is believed to be due to less genetic damage in non-smokers, being less susceptible to disease that would affect survival, and having better lung function. To some, it may be obvious that smoking can only make lung cancer worse, although many individuals cannot stop themselves. Hopefully these recent studies will make smokers more aware of their situation and how to take the necessary steps to recover.

Article: http://www.sciencedaily.com/releases/2006/04/060430003222.htm

Breakthrough in stem-cell research

After discussing stem-cells and their potential ability to replace defunct cells, this seemed like an interesting article. By injecting immature immune system support cells into the source of the injury, rats showed tremendous improvement within only two weeks. Stem-cell research is increasing at an astounding rate and advancements in spinal-cord corrections are becoming more of a possibility. When the spinal-cord is damaged, scar tissue is the body creates scar tissue to prevent infection, but makes it impossible for any implanted stem-cells to spur nerve growth. A group of scientists then postulated that the introduction of a stem-cell with the ability to repair itself could support nerve growth while preventing scar tissue. They cultured special glial-restricted precursor stem-cells which worked much better on repairing scar tissue and nerve damage. The neurons of these rats also did not atrophy as much as when injected with normal stem-cells. The data for moving glial-restricted precursors to clinical research shows promise, but the lack of stem-cells in the U.S. greatly impairs research. Fortunately, scientists are showing reason to believe that they will not even need stem-cells in the future because they will be able to make any cell into a stem-cell.

Article: http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20060426-19591300-bc-us-stemcell-spinalcord.xml

Cholesterol is good for you

In discussing the cell membrane and important molecules involved in its functionality, the importance of cholesterol to developmental proteins is an interesting topic. Vanderbilt University Medical Center researchers have discovered in mice that a lack of cholesterol during early development can cause additional digits to grow or digits to grow in the wrong location. There has previously been inconsistent data in relation to cholesterol’s role in the development of appendages, but this new research helps to better understand the developmental proteins. The specific gene in question, the Sonic hedgehog gene (named after a videogame character), is created “by a specialized group of cells located at the posterior part of the developing limb bud, which eventually develops into the pinkie finger or toe.” This gene is unique because it will not work properly unless a cholesterol molecule is attached to it. In order to test the effectiveness of the gene, a mutant Sonic hedgehog gene was tested to which cholesterol could not attach. Without cholesterol, these genes were dispersed in areas of the limb bud where they would not typically travel. This causes additional digits to appear where they normally would not, an affliction known as polydactyly. Problems with this gene can also be involved in a number of human conditions, including cancer. Further research of Sonic hedgehog gene and the importance of cholesterol can give better insight into embryo development and the prevention of related diseases.

Article: http://www.sciencedaily.com/releases/2006/04/060421234231.htm

Kinase Makes the News

Researchers from the Washington University School of Medicine used mice to study how a specific potassium gene regulates pain messages, according to an article from the Associated Press. Mice lacking a gene called Kv4.2 were more sensitive to pain than mice with the gene, which leads researchers to believe that pain medication could target Kv4.2 in humans and lead to the creation of new pain-reducing drugs.

Here's where kinase fits into the picture (remember talking about that in lecture?): It turns out that the Kv4.2 gene interacts with a molecule called ERK, short for extracellular signal-related kinase. Research has shown that pain can be lessened if ERK activity is hindered. Both ERK and Kv4.2 are responsible for the excruciating pain felt from things like oven burns. The experiment with the mice, which used heat as an indicator of pain, showed that normal mice with the Kv4.2 gene could handle heat on their paws longer than mice without it.

By understanding that Kv4.2 and ERK molecules heavily regulate one's perception of pain, future drugs interacting with these molecules could be more effective. Scientists acknowledge, however, that these drugs are many years of research and development away from reaching consumers, but that this discovery is a first step. These drugs might be useful for surgery patients and those with arthritis.

If you're really intrigued by kinases from this article and our lectures, check out http://www.kinase.com/ (no joke) for lots of information on kinases, including databases with over 1800 protein kinase genes.

Reasons for Cancer Spread Found in Protein

An article released yesterday by Reuters News Service and found in the Journal of Nature indicated that Austrian and Canadian researchers have identified and blocked a protein called RANKL, which is linked to cancer spread. The protein is found in bone marrow cells and was found to be a chief cause for cancer spread in mice because it sends signals attracting tumor cells to the bones. Cancer that has spread beyond its original area, which is called metastasis, is more difficult to treat. Metastasis causes a great deal of pain in cancer victims.

This finding explains why cancer cells can spread to bones and suggests that interfering with this process may stop the spread. Mice treated with a drug to block RANKL had fewer tumors in their bones than the untreated control group. However, the drug was not successful at stopping the spread of cancer to other places in the body. This finding relates to breast cancer cells, which often contain receptors for RANKL. The drug may improve the quality of life in patients if metastasis can be stopped. Researchers stress that these findings need further examination because the drug was tested only on mice.

The article suggested that there may be other proteins that are possibly involved in the spread of tumors, since RANKL only seems to be associated with cancer spread to the bones. It will be interesting to see if any other proteins, with further research, are identified that cause cancer to spread to other parts of the body. Perhaps then, like this experiment, drugs can be found to prevent their spread, making it easier to treat patients with different types of cancer. More information about RANKL, including its function and its signaling pathway can be found here.

Spring Break at Wal-Mart

A Drake University sophomore spent 41 consecutive hours at Wal-Mart to do background research for a writing article. Click on the link to find out more.

Bacon That's Good for You?

An article released Sunday by Reuters News Service said that U.S. scientists have genetically engineered pigs to produce beneficial fatty acids that could make foods like bacon much healthier. Researchers transferred a worm gene called fat-1 into pig cells and used cloning technology to create embryonic cells that were implanted into the womb of a normal pig. The gene allowed the pigs to produce an enzyme that converted omega-6 fatty acids (which the pigs naturally produce) into omega-3 fatty acids. Omega-3 fatty acids improve cardiac function, reduce the risk of heart disease and are necessary for proper fetal development in women. Omega-3s are only found in dietary supplements and certain types of fish, but some of these fish contain high levels of mercury. Omega-6 fatty acids are one of the reasons for high rates of obesity and heart disease. As of now, it is not known whether these genetically engineered pigs will ever be made available for human consumption. Researchers will conduct further tests on the effects of the additional omega-3s in the pigs. Experiments are also being conducted to try and make fish, chickens, and cows with extra omega-3s.

It will be interesting to see if these pigs actually become something humans consume on a regular basis. The article briefly touches in the ethical dilemma involved with genetic research like this. Consumers may avoid food like this out of fear of its unnatural properties. Whether these pigs will be specially labeled for their special qualities has not been determined. Most consumers eat genetically engineered fruits and vegetables, many of which are not labeled, without a problem.

More information on omega-3 fatty acids from the American Heart Association can be found here.

Grapefruit Juice Increases Drug Potency

A recent article from the New York Times (free subscription required for viewing), detailed how grapefruit juice can increase the potency of some drugs to potentially dangerous levels through its inhibition of certain enzymes.

A group of enzymes called the cytochrome P 450 system, specifically an enzyme called CYP 3A4, held the answer as to why grapefruit juice increased the power of certain drugs so greatly. These enzymes break down many drugs and toxins into substances that are "less potent or more easily excreted or both," according to the article. Grapefruit juice inhibits the ability of CYP 3A4 to break down these drugs, increasing its potency because more can enter the bloodstream. The drug specifically binds with the enzyme in the intestines, so this effect can only happen if the drug is taken orally.

The vast majority of grapefruit juice’s interactions with drugs are not very serious, though some special cases do arise. Cholesterol lowering drugs like Lipitor and Zocor have increased potency, which can lead to a fatal muscle disorder. Grapefruit juice can also hinder the metabolism of drugs like Prozac, used to treat depression. Grapefruit juice has the greatest effect, but lime juice and orange juice made from Seville oranges affect the enzyme in similar ways.

Solution: take the drugs with water.

The X Advantage

Genetic research into differences between the sexes is increasingly showing that the extra X chromosome in women helps them fight off disease and may be the reason for their increased lifespan. Men are born with one X chromosome and a much smaller and relatively "weak" Y chromosome, which is involved in the development of male characteristics. Women are born with two X chromosomes.

In the United States, according to 2003 U.S. Census data, women live an average of 80.1 years, while men only live an average of 74.8 years. More males die of chromosomal defects than females do.

The X chromosome has about 1,100 genes on it that are involved in blood clotting, muscle function, and ridding cells of waste, among other things. It may also be the reason why girls comprehend colors differently, develop different personality traits and acquire longer attention spans. If a defect or mutation occurs on the X chromosome in a male, he is stuck with the defect whereas females have a back-up copy of the chromosome. Females can be considered "mosaics," since in a given cell only one of the X chromosomes can be expressed. Cells can express either the father's X chromosome genes or the mother's X chromosome genes in a cell, which leads to more variety overall.

Though the article does not mention it, it probably is incorrect to assume that the X chromosome is the only reason females, on average, live longer than men. There are many factors contributing to longevity, including nutrition, environment, occupation, and lifestyle, to name a few. But the article provides compelling evidence to suggest that the double X chromosome is at least part of the reason.

HealthDay News Article
More Information on Sex and Disease

We need more gas

Hi. Some organisms, instead of releasing carbon dioxide or oxygen as waste poroducts, release methane gas. Bacteria that do this are called methanogenic bacteria. San Francisco has developed a plan to recycle dog droppings using methanogenic bacteria. The bacteria would use the dog droppings as an energy source, and produce methane as a waste product. The methane could be collected and used as a source of energy for heat, barbecue grills, and maybe even golf carts.
Eco-Farm

Blogging for fun (and extra credit)

Part of the extra credit grade in our class can be earned by finding information in the popular literature (newspapers, magazines) about new developments in cell biology. You will be surprised at how much information is available. Furthermore, you will find that blogging is like Doritos: distasteful at first, but pretty soon you are eating three bags/day.

Here are the ground rules:
You can earn up to 3 points/blog entry, up to 14 points.
No duplicate posts. If someone found an article about a topic, you can't post about the same topic.
You must have at least two links in your blog entry: one to the original article, and one to a related site (see my blog entries for examples).
You must write a short paragraph (5-7 sentences or so) about the article, giving a little information about what the article is about, as well as what you think it means. Once again, see my blog entries for examples.

The Blogger software is _really_ easy to use, if you have ever used Word, Powerpoint, or Internet Explorer (LOL). PC users are good to go using IE, but Mac users should use Netscape or IE to edit their posts, and Safari to add pictures (adding links in Safari is a pain, unless you know a little html).

Image Manipulation=Bad

While the vast majority (99%) of science articles are honest, sometimes, as in the case of the recent human stem cell controversy in South Korea, fraudulent data sees the light of day. The peer review system, in which articles submitted to scientific journal are read by other scientists prior to publication, works very well, but sometimes researchers can inappropriately manipulate image data with Adobe Photoshop. As anyone who ever "photoshopped" their friend into a group picture knows, it is pretty easy to change a picture. Scientists are allowed to change, for example, the brightness and contrast of an image, so long as the entire image is changed equally. However, sometimes even scientists can get a little carried away and change pictures in inappropriate ways, either inadvertently or advertently. This article has a nice explanation of the issue, and certainly raised my eyebrows a little bit.

Journal of Cell Biology link

Stem Cell Researcher Interview

As you may know, the federal government has banned the use of federal funds to support human embryonic stem cell research. There is an interesting article in today's New York Times about the practical issues surrounding the boundary between publicly and privately supported research. The reporter interviewed Dr. Douglas Melton, Director of the Harvard Stem Cell Institute. The article also raises interesting personal issues, as Dr. Melton has children who may benefit someday from stem cell therapies.

Link to Harvard Stem Cell Institute

Dogs can smell cancer

Dogs can smell 10,000-100,000 times better than we can, a feature that can be of great use (police dogs that can find explosives) or not, as when taking a dog for a walk. Researchers have known for many years that cancer cells emit volatile compunds that normal cells do not, and anecdotal evidence suggested that dogs can detect skin cancer. To test this idea, researchers trained dogs to sit next to breath samples from patients with lung or breast cancer, but ignore breath samples from unaffected patients. The dogs make the correct choice 99% of the time using samples from lung cancer patients, and 88% of the time using breast cancer patient breath. Previous studies showed that dogs may be able to detect specific compounds in the urine of patients with prostate cancer. These detection rates are much greater than currently available technologies. This finding, if developed further, may lead to new early detection strategies.
NYTimes (free subscription required)
National Geographic
CBS News

Welcome to Cell Bio in the News @ the University of Richmond

Hi. This is the blog posting site for Biology 205, Cell and Molecular Biology, Spring 2006. I'm the faculty member teaching this section of the course. Students and I will post brief descriptions of interesting science articles related to cell biology. Please feel free to post comments. Thanks.