Some fun facts about blood:
There is no substitute for blood.
Red blood cells live about 120 days.
Plasma, which is 90 percent water, is a pale yellow mixture of water, proteins and salts.
Thirteen tests are performed on donated blood, 11 are for infectious disease.
94 percent of blood donors are registered voters.
Newborn baby has about one cup of blood in his or her body.

Biologists would like to understand how a bear, who eats continuously throughout the summer to lay down fat reserves for the winter, can have cholesterol levels that would be high for a human, but not suffer the hardening of arteries that one might expect. And what about the bone loss one would expect from months of inactivity?  Humans on bed rest can lose 3-4% of their hip bone minerals from lack of weight bearing exercise.  Bears show no signs of bone loss or osteoporosis as a result of their long rests.  It is likely that the genes involved exist in our cells too, but they just aren’t being used in the same way.

We clearly have a lot to learn from our hibernating friends. Teams of researchers in Sweden have actually been studying Brown bears to learn about these interesting phenomena.  How do you study wild Brown bears you ask?  You tranquilize them while they are hibernating, collect as many samples as you can, and get out before they wake up!  For the full story on hibernation, go to: http://www.sciencenews.org/view/feature/id/338318/title/Lessons_from_the_Torpid.

C. elegans Roundworm

The aging process is, and always will be fascinating to us.  It’s role in an organism’s ability to reproduce is currently being studied in worms at Princeton University. The microscopic roundworm C. elegans lives for about 21 days.  For the first nine of these days, hundreds of eggs are fertilized producing an abundance of offspring!  After day nine, the many remaining eggs won’t be used, as their quality is poor and they cannot produce viable embryos.  A process similar to this takes place in humans.  Women experience a sharp decline in fertility in their late 30’s. In worms and in humans this is an early sign of aging.

Interestingly enough, there are genes that play a vital role in protecting cells from the aging process!  In somatic (or non-reproductive) cells, these “stress management” genes protect proteins and affect the metabolism of the aging cell.  Scientists at Princeton have discovered that although oocytes (egg cells) also age with time, the activated genes are different than those used by somatic cells.   Reproductive cells use genes that protect from DNA damage, repair DNA damage and make proteins that help eggs split up their chromosomes correctly. Another finding is that the genes associated with longevity (how long a worm lives) are completely independent of the genes that extend fertility.

It makes sense that the cells responsible for carrying genetic information forward to the next generation devote a number of resources to preserve themselves.  Surprisingly, this had never been shown before.  This new understanding of the genetics of fertility, will most likely affect how doctors approach the question of infertility and develop methods to curtail the inevitable aging of our eggs!

If an individual becomes infected with harmful bacteria they may be prescribed antibiotics to rid the body of that infection.   As the antibiotic begins to work, the harmful (and some helpful) cells will be killed off but not all of them.  When start to eliminate a number of the bacteria making you ill, you will probably start to feel significantly better.  At this point it is important to continue to take the antibiotic until the prescription is complete.  The reason is that after a few days of the antibiotic some of the harmful cells will still be alive in your body.  It is possible that these cells will take up genes for resistance to the antibiotic from some of the other bacteria that are already living inside of you.  These harmful cells with newly acquired resistance genes will divide and produce clones of themselves.  Unfortunately you will start to feel sick again and if you tried to take the remainder of your antibiotic they would have a defense against it.  

The fact that different types of bacteria can share genes enables them to survive under selective pressure.  Just one of the amazing charactericstics of these simple cells.  Although we may think of bacteria as a nuisance they have much to teach us.

I remember having the chicken pox when I was in sixth grade.  Since I was the first person in my school to get it at the time I remember being amazed every time I heard someone else came down with it because I knew it had come from me.  Where had I picked it up though?  The whole idea of this virus traveling from one person to the next fascinated me.  At the time I just assumed the viruses inside me had been destroyed by my immune system.

I grew up and learned more about viruses but never really studied them.  I am only recently starting to delve into their amazing history and mechanisms for survival.  Until recently I did not understand what the relationship was between chicken pox and shingles.  I was mistaken to think the virus that infected me years ago was eradicated from my system, this is a virus that lays dormant even after you have had the symptoms associated with the infection.

The virus that causes chicken pox, varicella-zoster virus (VZV), remains inactive in nerve cells and can reactivate later in life.  This second infection is referred to as shingles and can be quite serious.  Symptoms of shingles pain throughout the body, numbness, tingling, aches, and a blistering rash.  The discomfort may last for several weeks or even in severe cases, years.

Although we have all been affected by viruses and many of us are fearful of them, so much about them remains a complete mystery to the general population.   I am eager to find out more.  What do you want to learn about them?

I happen to work at an institution where evolution is revered as the underlying theme that explains life and all of its processes.  For a biology teacher it’s a comfortable place to be.  I suppose I am spoiled. When I travel to schools, I am on occasion told by teachers how happy they are that I am presenting evolution for them.  It is a required part of the New York State science curriculum, but some of the teachers who are supposed to teach it, don’t want to.   It makes me wonder.  Are they uncomfortable with the science?  Are they afraid of parents or students lashing out at them?  Does the scientific theory of evolution somehow conflict with their religious beliefs?   I don’t know the answer.  I’m sure it’s a combination of several factors. 

My gut feeling is that most teacher reticence is due to lack of understanding.   I would feel very uncomfortable if asked to teach a topic I didn’t fully understand, and unfortunately this is what’s happening.   I think we need better teacher training, especially for elementary teachers who receive very little training in science.  Everyone who receives a degree in general education or in science education should have to complete a course in basic genetics and/or evolution.   This would significantly reduce the negativity associated with teaching evolution, and could help produce much happier teachers!

The timing of this internal clock is related to the amount of exposure to light.  How do circadian rhythms work in organisms that are not exposed to light?  A Somalian cavefish, Phreatichthys andruzzii, is a blind species that has been living without light for approximately 1.4 to 2.6 million years!

Researchers compared the cave fish to zebrafish during exposures to 12 hour period of light followed by 12 hour period of dark.  The cave fish remained active at irregular times while the zebrafish were active during exposure to light.  Also, it was identified that in the zebrafish, genes associated with circadian rhythms were activated from exposure to light while the same genes in the cavefish were not.

In addition to light, these rhythms can also respond to other factors, including food.  When scientists fed both types of fish at specific times for a month, they found that both fish were ready to eat at those times, demonstrating the circadian rhythms.  Also, the genes associated with the rhythms were activated in both fish.

Photoreceptors are cells with specialized proteins that respond to light.  While the genes associated with circadian rhythms in the cave fish were normal but not activated, it was found that genes for certain photoreceptors were mutated.  The mutation caused important sections of the photoreceptors to be missing.  After introducing functioning genes into cave fish, it appears that these transgenic fish could only respond to blue and green light.  This tells us that there are photoreceptors for light that we do not know about!

The cave fish offers scientists an opportunity to learn more about not only circadian rhythms, but also the mechanisms behind how we respond to various forms of stimuli. 

Interestingly enough, inhalable toxins can be detected in airways, just like they would be on the tongue. The airway response to detection is what’s most interesting.  One school of thought is that logically, when bitter toxins are detected in the lungs, the airways will close.  This prevents the toxin from entering the lungs, makes breathing difficult, and inevitably forces the individual to leave an unhealthy environment.

What has been observed though, is quite the opposite.  In mice, inhaled quinine (a bitter compound) caused the airways to relax, instead of constrict! In fact, quinine worked better than albuterol (a drug commonly used to treat asthma) at relaxing airways. There must be a benefit to having such a reaction.  It has been proposed that opening airways may reduce the risk of infection or aid in clearing infection when toxins are inhaled, but it is still unclear.  What is clear, is there will likely be new asthma medications developed in response to this interesting genetic trait!

How is it possible that some organisms have the ability to survive in some of the dirtiest places on earth?  What survival mechanisms do they have that differ from ours?

Scientists ground up the brains and other nerve tissues from two species of insects, the American cockroach and the desert locust.  Material extracted from the samples was shown to kill more than 90 percent of a harmful type of E.coli bacteria.  In addition, the tissue extracts killed a type of staph bacteria.  There seem to be nine molecules within the tissue that are involved in defense against microbes.

Although the nine molecules have not been identified, scientists may be able to utilize the molecules in the future as a form of disease prevention in humans.

Scientists have recently identified a section of “junk” DNA that can regain function and cause disease. The section of DNA is made of repeat regions of the same sequence. They found that individuals who have 1-10 repeats on the end of chromosome 4 can develop one of the most common forms of muscular dystrophy, FSHD. The goal now is to identify a way to turn off this once non-functioning gene.

One of the important insights from the resurrection of this gene is that although some diseases can be easily explained, others result from very complicated cellular interactions. What other information will our “junk”DNA reveal in the future?

To learn more about the effects of this gene being turned on read the paper published in Science: http://www.sciencemag.org/cgi/rapidpdf/science.1189044.pdf