Another reader wanted to know why there are cures for other diseases, but not for cancer. There are many reasons for this, of which I’ll mention a few. First, cancers are the result of our own cells acting abnormally. This means that many of the treatments we might want to use to kill cancer cells would also kill our normal cells. The challenge is to identify the differences between our normal cells and their cancerous relatives and then to identify weaknesses in the cancer cells. This in itself is very difficult. However, it is much more difficult because cancers are not all the same. As I mentioned above, cancers in different tissues arise by distinct changes, so a drug for one cancer may have no effect on another. Even worse, different cancers within a particular tissue are different. In fact, within one tumor, the different cells can have different mutations, and these can affect how the cells respond to therapy or allow the cancer to develop drug resistance. So, cancer isn’t just one disease- it is many related diseases. In fact, calling for “a cure” for cancer isn’t really fair; what will be needed are many cures for this family of diseases.

I know I’ve probably produced more questions than answers, but I hope that this helps some of you.

Typically, Alzheimer’s is diagnosed through cognitive testing.  Family members or health care professionals may realize that a person is experiencing forgetfulness, disorientation, or other symptoms. Unfortunately, by the time these symptoms are apparent and a diagnosis is made, the patient may have already experience a great deal of brain damage.

A new method to test for Alzheimer’s at a much earlier stage of the disease has been described in a paper in the journal Neurobiology of Aging, (10.1016/j.neurobiolaging.2010.04.025) where Laurel Beckett et.al. describe  a method of diagnosis based on a combination of imaging and sampling of cerebrospinal fluids to categorize individuals into at-risk groups before clinical signs of Alzheimer’s appear.

This important work could have a two-fold impact on the fight against Alzheimer’s. By identifying at-risk patients early, medical intervention may be able to at least delay the onset of the disease. The early identification of at-risk individual also would accelerate the development of clinical interventions because you have now isolated a population that can participate in clinical investigation and broaden the horizon of time investigators have to work with, increasing the rate at which further discovery can proceed.

E. coli gets a bad reputation and I understand that. My students immediately cringe and I know what goes through their minds. They think of the E. coli outbreaks we’ve had in our foods as of late such as the ones that are leading to cases of severe food poisoning and death. I can quickly reassure them that this bacteria does not have this capability. In fact, many are surprised to learn that not all bacteria can cause harm.  With the bad also comes the good and there are good bacteria as well.

Bacteria have taken up residence everywhere on and in you. Hundreds of species of bacteria live on your skin, live in your mouth, and in your intestines. Everyone is born sterile (completely clear of bacteria), but soon after birth bacteria moves in and multiplies enough to include more bacteria cells than human cells in your body.

Don’t get too grossed out! These bacteria strains are important. For example, Biologist Jeffrey Gordon of Washington University has a group of mice that are completely gut bacteria free. These mice are very different from their non-sterile cousins in the way that they are extremely skinny. Food passes right through their intestines, mainly undigested. Thus it is shown that the gut bacteria are more efficient at digesting our food than we are alone.

Today, the bacteria in our guts seem to do more things than originally thought. They are currently under investigation in studies of Autism. There is a hypothesis that these gut bacteria might be releasing chemicals that are contributing to the onset of Autism. Autism has already been linked to gastrointestinal problems. These gastrointestinal problems also seem to appear around the same time as behavior symptoms, so perhaps these gastrointestinal microbes have something to do with it.

Researchers in the UK are studying chemicals in the urine of people with Autism compared to those without the condition to detect any chemical differences. These metabolic changes might be detected in the urine. Using nuclear magnetic resonance (NMR) spectroscopy, the urine was analyzed. The results showed a clear difference between the two groups.

There is a theory that these gut bacteria are producing a toxin that might interact and disrupt brain development. One compound that was identified using the NMR spectroscopy was N-methyl-nicotinamide (NMND) which has already been linked to Parkinson’s disease.

At the University of Western Ontario in Canada, Derrick MacFabe and his colleagues have discovered that clostridium bacteria produce a short-chain fatty acid that many cause autism-like behavioral and biochemical changes in rats that can be reversed.

With this possible link, there might be a simple urine test for Autism. This test, done early enough, might then lead to earlier therapy and treatment options.

Physicians, Psychologists, and people in general have always held differences of opinion when it comes to how to think about mental conditions. Some people may think depression is simply a “bad mood” that should be “snapped out of” while medical evidence has shown that physiological components of  these diseases make them just as “real” as a broken bone.  The link between hypertension and bipolar disorder is just one of the latest correlations between mental disorders and other conditions such as diabetes and heart disease.

While in many cases it is not totally clear what causes what (i.e. does the stress of bipolar predispose the development of hypertension, or the other way round) the study by Dale D’Mello does suggest the need for doctors to consider the importance of tending to physical health as a complement to treating mental conditions. Without getting into the mind/brain/body debate, it only makes sense that any contribution to “physical” health will ultimately improve patient outcome, if even only indirectly.

Scientists from the University of Geneva have shown that alpha cells in the pancreas of mice have changed to insulin producing beta cells. In the study, approximately 5 % of the alpha cells became beta cells. The response seen only occurs in mice when the majority of the beta cells have been eliminated. If scientists can find a way to encourage human cells to transform in a similar way while preventing the immune system from destroying the new cells, even a small percentage of new beta cells could make a huge difference in the life of a diabetic.

Identification of the mechanisms that transform alpha cells into beta cells will not only help in the treatment of diabetes but can reveal insights into the ability to direct changes in other cells, including cancer.

PDF of the Article In Nature:

http://www.nature.com/nature/journal/vaop/ncurrent/pdf/nature08894.pdf

One very amazing example of this is the Widowbirds that live in the grasslands of southern and eastern Africa.  During the non-mating season, the males and females look very similar to one another.  Once breeding season begins, the males molt and produce long black feathers, some that can be up to half a meter in length.  Studies have been done where feathers have been glued on to some males, and females chose these males over others with shorter tails.  You also have to wonder why the tails don’t get even longer.  That even though females desire very long tails, if they get too long, they could hinder the flight of the birds, which would decrease their fitness.

Other examples that might be more familiar to you are the elaborate feathers of male peacocks, and the beautiful plumage of male birds.

The foods we eat also have a big effect. I think back on what my mother used to preach, and I think she had it right. She told me to eat my greens and have lots of fruit. On the other hand, somehow she knew too much alcohol, red meat, and sugary drinks are bad. “Where did all the ice cream go?” echoes from the past. My hiking and canoeing mother encouraged me to do sports and other outdoor activities. I knew these choices were healthy and protected me from heart disease. What I didn’t realize was that my mother was protecting me from cancer, too.

The World Cancer Research Fund has recommendations for how to prevent cancer. I think they interviewed my mom.

Here are some of them:
• Be as lean as possible in the normal range of body weight
• Be physically active every day
• Avoid “energy-dense” foods and sugary drinks.
• Eat lots of non-starchy veggies and fruit
• Limit red meat and processed meat in your diet
• Avoid salt

You can check out the details and see the whole list on their web site:

http://www.wcrf.org/research/expert_report/recommendations.php

Now that I have passed on my mother’s preaching, you have yet another reason to eat well and exercise. I’m off to the gym… to fight cancer and heart disease at the same time!

The most mystifying of the model organisms is the plant. How could a scientist possibly learn anything about human genetics from a plant? One popular model from the plant kingdom is a weed from the mustard family found all around the world called Arabidopsis, or Thale Cress. It has a small genome, and as such, was the first fully sequenced plant genome! In addition to studying plant traits useful for agriculture, such as light sensitivity and flowering, there are other important cellular traits being studied in plants.

What most students don’t realize (until they are actually asked to think about it) is that all cells perform basic functions, and these basic functions are required for life. Interestingly enough, mutations in genes involved in the regulation of the most basic cell functions such as cell division, are the culprits in diseases such as cancer. Telomeres, structures that cap chromosomes, are found in plant and animal cells and also play a potential role in basic functions like cell division. Recent Arabidopsis research may shed light on the relationship between telomeres and cancer!

(http://www.sciencedaily.com/releases/2009/10/091026162538.htm)

So the next time you’re out weeding the garden, take a moment to consider this: that plant you’re uprooting may contain valuable information!

Chromosomes are passed from parent to child. For many animals, including us, the X and Y chromosomes determine gender. For most mammals, the presence of two X chromosomes indicates a female, while the presence of one X and one Y chromosome indicates a male. For a cat, the alleles (types of genes) that determine orange or black color are located on the X chromosome. A female cat inherits two X chromosomes from each parent. A male inherits only one X from his mother and a Y from his father. For the male, there should be only two possible outcomes for color:

X (orange) Y – an orange male cat or X (black) Y – a black male cat.

A female inherits an X from each parent. She can receive three possible outcomes for color:
X (orange) X (orange) – a female cat with orange coloring, X (black) X (black) – a female cat with black coloring, or X (orange) X (black) – This cat’s coat has patches of orange and black. This example is not so straight forward.

What happens with X(o) X(b)? With two X chromosomes, only one is actually used. The other one is actually “shut down.” This is called X inactivation. One of the X chromosomes will “super coil” into a structure called a Barr body (like a zip drive on a computer). This process is called lyonization. This happens very early in embryo development. When there are different alleles on each X (known as a heterozygous genotype, or in this case – one X with orange, the other with black), the X that gets “turned off” is random in each individual cell. This is what causes the patchiness of the cat’s coat. Each patch is made from cells that descend from that first cell that lyonized to be a certain color. These “patchy” cats are called “calico”. Since males only have one X chromosome, they cannot be calico.

So, how does this explain “Eddie,” the male tortoiseshell calico kitten, born in England? As with almost every rule, there is always an exception. Apparently, in very rare cases (some say the odds are 1 in 3,000), a male cat can inherit a Y chromosome and two X chromosomes, making his genotype XXY. If this male is lucky enough to inherit X (o) X (b) Y, then he will be calico.

Unfortunately for Eddie, and all the other male calico cats out there, the extra X chromosome interferes with the production of viable sperm. Therefore this leaves the poor kitties sterile. In humans, this disorder would be called Klinefelter Syndrome.

Eddie seems to be a perfectly normal, male calico cat.

You can find more on this rare case at: http://www.pawnation.com/2009/09/01/tortoiseshell-cat-shocks-britain-with-family-jewels/