Wednesday, December 9, 2009

Another posterior pituitary hormone


A recent paper in the Proceedings of the National Academy of Science shows that that the posterior pituitary (neurohypophysis ) secretes another hormone besides antidiuretic hormone (ADH; vasopressin) and oxytocin (OT).  It is the hormone secretin.

Secretin is already known to be secreted from the intestinal lining, having a variety of effects in regulating stomach and pancreatic function during the digestive process.  New findings indicate, however, that secretin is also secreted by the posterior pituitary.

Neurohypophysial release of secretin is triggered by plasma hyperosmolality—as in dehydration of the body. Secretin then promotes the expression and release of ADH, which in turn promotes water conservation by the kidney.  Secretin also appears to have direct water-conserving effects in the kidney as well.

Want to know more?

Secretin as a neurohypophysial factor regulating body water homeostasis
Jessica Y. S. Chu, et al. 
Proceedings of the National Academy of Science  September 15, 2009 vol. 106 no. 37 15961-15966 
doi: 10.1073/pnas.0903695106
[Abstract of the recent paper.]

Highlights From The Literature
Physiology 2009 24:322-324
doi:10.1152/physiol.00037.2009
[Summary of the significance of this discovery.] 


Click here for a FREE 3D see-through image of the pituitary's location that you can use in your course.

Too late for cadaver class!


I had hoped to tell you all about a great new course offered by HAPS Institute . . . Anatomy of the Abdomen and Thorax . . . but it filled up in less than half a day!

Lucky for us (and the dozen or so folks on the waitlist), this is the first in a series of several courses that center around a weekend workshop in a cadaver lab with expert dissectors.

The Anatomy of the Abdomen and Thorax course held in February in San Diego is just the first in a series of courses that will be held at various locations in North America in the coming months and years.

These courses carry three graduate credits from the University of Washington (Seattle) biology department. All HAPS-I courses are meant for folks who already teach anatomy and physiology (high-school through graduate levels) fill in their background in various topics within human biology . . . or simply to brush up on the lastest concepts.  Even if you already have a graduate degree and "don't need the credit" you'll find these courses to be both fun and useful.

All HAPS-I courses also involve emerging methods of active learning and thus showcase methods of teaching and learning that participants can adapt into their own courses.

Want to know more about HAPS-I and its courses? Click here for more information.

However, when new HAPS-I courses open up . . . ACT QUICKLY because they DO fill quickly!

Sunday, November 8, 2009

Bacterial microbiomes on human skin

Nearly a year ago, I shared results of a study of the bacteria that live on human skin, including these fun facts:
  • Females have a higher diversity of bacteria on their hands than males . . . perhaps due to a slightly higher skin pH in women, or perhaps the mix of sebum, sweat, and lotions, or maybe even hormonal differences . . . they couldn't really say for sure at this point
  • Females have more bacteria living under the surface film of skin than males
  • 4, 742 different species of bacteria were found in the whole group of subjects
  • The species each of has on our hands is a rather unique mix--only 5 (out of 4,742) species were found on every hand in the group
  • Most of the 150 or so different species of bacteria found on skin of an individual hand are beneficial or harmless . . . only a small minority are pathogenic
  • The diversity of bacteria differs between a person's right hand and left hand
  • Hand washing (as practiced in this group) did not remove many of the bacteria (or the populations recovered rapidly after washing)
Recently, another study was published that gives us an even more complete picture of the micro-ecology of human skin.  The report, published online a few days ago by the journal Science, provides an inventory of what organisms live where on the human skin.

A few fun facts about the bacteria, viruses, and fungi of the human skin gleaned from the new study:
  • Microbes on the skin outnumber human cells by at least 10 times (about 100 trillion microbial symbionts)

  • Microbial community composition is determined primarily by habitat (well, of course!)

  • The composition of microbial communities varies widely from one person to another

  • The compostion of microbial communities for an individual human do not vary much over time

  • Some locations of the skin harbor more diverse communities than even the mouth or gut
Want to know more?
Bacterial Community Variation in Human Body Habitats Across Space and Time.
Elizabeth K. Costello, et al. 
Science Express, 5 November 2009, online .
doi: 10.1126/science.1177486
[Recent study on human flora]

Bacteria Flourish in Favorite Ecosystems on the Human Body
Laura Sanders
Science News November 5, 2009
[Nice summary of the study's importance and implications]

Variation In Bacterial Populations From Person To Person Surprises Researchers

C. Paddock
Medical News Today 6 November 2009
[Press release about the new study]

Skin Ecology
K. Patton
The A&P Professor 18 November 2008
[My previous article on the topic.  Includes links to other articles.]

Why cells cooperate


Here's a nice little "animated clay" video that zeroes in on the "society of cells" concept that lies at the heart of homeostasis.   Because it goes on to emphasize the role of reproductive cells in a multicellular organism, it may be useful to help our A&P students connect reproduction to the concept of overall body homeostasis.

I saw this video on public radio's Science Friday website, where they have a weekly video recommendation.

The video comes from a collection of videos at creaturecast.org that are truly amazing.  Not very many directly relate to human anatomy and physiology . . . but, wow, they are fascinating.  For example, a recent posting discusses how mitochondria and other erstwhile endosymbionts can play a variety of roles such as acting as lenses for simple animals. I teach the serial endosymbiosis theory (SET)  in my A&P course . . . so this little factoid may help spice up that discussion.

So watch the FREE video about cell cooperation in a multicellular organism and let me know what you think!


H1N1 teaching moments


Although the typical A&P class is not focused primarily on pathology, we certainly do use pathology frequently as a tool to illustrate "normal" structure and function by looking at what goes wrong in injury and disease.  This works especially well when a disease or injury . . . or affected celebrity . . . is in the current news.  The current pandemic H1N1 outbreak gives us opportunities to teach some important concepts:
  • what do "public health" scientists do, and how do they do it?
  • what is a virus and how does it affect cell and body function?
  • how do vaccines protect the body?
  • why do some infections have a greater affect on some people than others?
  • how are viral infections spread?  how are they treated?
A recent news release posted at Science Daily summarizes a striking issue related to the flu vaccinations.  It highlights a paper recently published in The Lancet, which concludes that vaccination campaigns can be underminded by the public's tendency to link coincidental health events with vaccination campaigns.

Haven't we all see and heard of such associations?  They are even promoted by some otherwise trustworthy media outlets.  For example, many people are convinced of the strong relationship between certain vaccine preservatives and autism . . . even though thorough scientific investigation has shown no link.  An "outbreak" of Guillain–Barré Syndrome during the 1976-77 swine flu vaccination program turns out to be consistent with the number of people expected to contract this syndrome whether or not a vaccination program occurred.

In short, people get sick all the time and we should not automatically conclude that coincidental events are necessarily cause-and-effect scenarios . . . or even related at all.  And yet . . . we do.

This information is useful in teaching about how the scientific method can be used to answer questions.  In addition, the CDC's current surveillance methodology can be explored to illustrate how a scientific approach can be used in practical ways to watch for actual problems that could arise in a vaccination program.


In a somewhat related development, psychologists recently reported in Psychological Science that seeing and hearing a person sneeze can trigger fear or a "doom-and-gloom" attitude in healthy individuals.  I guess we should be cautious when exposed to sneezes, but the study showed that we tend to take such stimuli far more seriously than we realized.

Want to know more?
Pandemic Flu Vaccine Campaigns May Be Undermined By Coincidental Medical Events.
Cincinnati Children's Hospital Medical Center ScienceDaily. (2009, November 6)
[News release summarizing conclusions of a scientific study]

Importance of background rates of disease in assessment of vaccine safety during mass immunisation with pandemic H1N1 influenza vaccines
Black, S. et al.
The Lancet (early online publication) 31 October 2009
doi:10.1016/S0140-6736(09)61877-8
[Original peer-reviewed article]
Sneezes Provoke Fears Beyond Illness
Karen Hopkin
Sceintific American Online November 4, 2009
[Link to the podcast version or read the text summary]
[Here's an interesting clip to add to your PowerPoint or course web page . . . the first filmed sneeze ever recorded!  It was made with Thomas Edison's kinetoscope and was the first motion picture copyrighted in the United States.  Click here to see it http://bit.ly/j0Mzf ]

Monday, October 26, 2009

Revisiting the spleen


I'll never forget that snowy day all those years ago when my friend Keith slammed his sled into a laundry pole and ruptured his spleen.  Perhaps as an expression of our shock and concern for him as he lay in his hospital bed after his splenectomy, we spent an afternoon wondering to each other, "what IS a spleen . . . and how can you live without one?" 

As we all know, the spleen has a number of functions including acting as a blood reservoir and as a site of lymphocyte development and activity.  Research published a few months ago has now expanded our understanding of this odd organ.

According to the new research, another function of the spleen is to serve as a reservoir of monocytes that can be called upon during tissue injury in other locations of the body.  The splenic monocytes, which far outnumber the monocytes circulating in the bloodstream, form clusters in the cords of red pulp just under the capsule (wall of the organ).  From there, they move in a group out of the spleen and to the site of injury.  There they help remove and repair damaged tissue. 


This is a FREE image (click for source).
You can use it in your course.



Want to know more?
Identification of Splenic Reservoir Monocytes and Their Deployments to Inflammatory Sites
Swirski, F. K. et al.
Science 31 July 2009: Vol. 325, no. 5940, pp. 612-616
DOI: 10.1126/science.1175202
[The original research article.  A particularly clear abstract.]

Dispensible But Not Irrelevant
Jia T. et al.
Science 31 July 2009: Vol. 325. no. 5940, pp. 549 - 550
DOI: 10.1126/science.1178329

[Editor's summary of the implications of the original research.  Full text version includes a great diagram of this newly discovered role of the spleen.]

Finally, the Spleen Gets Some Respect
N. Angier
The New York Times 3 August 2009
[Article summarizing the new findings.]

While we're on the subject of the spleen, have you seen the images of a pelvic spleen published recently in the New England Journal of Medicine?  The piece in the NEJM briefly documents the case of a rare condition in which the spleen my drop into the pelvic cavity when there is problem with the suspensory ligaments of the spleen.

Pelvic Spleen: Images in Clinical Medicine
Tseng and Chou
New England Journal of Medicine 361 (13): 1291, Figure 1
[Images.  Includes link to FREE PowerPoint slide for subscribers]


 For a few FREE images of the spleen, go to the Lymphatic Image Library at The A&P Professor website

Keeping time


Finally . . . a physiological explanation for why I have such hard time keeping time when trying to dance.  Any of you who have seen me on the dance floor at a Human Anatomy and Physiology Society (HAPS) conference know what I mean!

It turns out that there are time-keeping neurons in our brains.  Specifically in the prefrontal cortex and striatum of the cerebrum. Discovered recently in the brains of monkeys by researchers at MIT, these time-keeping neurons fire consistently at certain rhythms . . . thus helping our brains to figure out when things are happening.  This helps us with rhythmic activities, of course, but also with any number of tasks and memories that rely on knowing what came first, in what order, and so on. 

Researchers speculate that damage to these neurons, or damage to the mechanisms that read the timing pattern, may contribute to disorders (such as Parkinson Disease) that involve ill-timed movements and other functions.  And perhaps may explain why Kevin has a such a hard time dancing.

In their paper, researchers failed to speculate whether this is why A&P students know exactly when to start slamming their books shut moments before a class is scheduled to end.

Want to know more?

Neural representation of time in cortico-basal ganglia circuits
Jin, DZ et al.
Proceedings of the National Academy of Sciences, 22 Oct 2009


[Original research article]




Time-keeping Brain Neurons Discovered

Massachusetts Institute of Technology (2009, October 23).
[Press release summarizing the context of the discovery.]

Monday, October 19, 2009

Why the Golgi apparatus looks so funny


Did you ever wonder why the Golgi apparatus looks so odd, compared to other membranous organelles of the cell?  I mean, really, wouldn't you think that the forces causing other membrane-bound structures to form more of a globular shape would cause the cisternae (sacs) of the Golgi apparatus to be more, well, round?

A few days ago, the journal Cell published an article that answers that question . . . revealing an elegant mechanism resulting from the primary function of the Golgi apparatus.

As we know, the Golgi apparatus "processes and packages" proteins that arrive from the endoplasmic reticulum (ER) by way of ER vesicles. The central structure of the organelles is the Golgi stack or dictyosome, which resembles a stack of hollow pancakes. Vesicles pinch off of the first cisterna (cis face) and move to the next cisterna, then the next, and finally to the final cisterna (trans face).  Then a vesicle pinches off and moves to the plasma membrane, where it fuses and releases (secretes) it contents to the outside of the cell (exocytosis). Click here for a simplified video summary.

The new data suggest that the budding of vesicles and their movement toward the plasma membrane rely on the function of a protein called GOLPH3.  This tiny protein connects special phospholipid molecules [PtdIns(4)P] in the Golgi membrane to myoglobin molecules (MYO18A).  The myoglobin, in turn, is attached to F-actin filaments of cytoskeleton.  Well, you know what that means, right?  Yes . . . the myoglobin is a motor molecule that pulls the attached Golgi membrane along the F-actin filament, stretching it out into its familiar elongated shape.  Then thwap! . . . a vesicle pinches off and is carried away.

In short, the Golgi membranes flatten out because they are being pulled outward by the cytoskeleton in a process that produces budding of vesicles.  As simple as that!  Now, when you're describing this amazing little organelle in your A&P class, you have a new little twist to add to the story! 


By the way, the terms Golgi complex and Golgi apparatus, which are synonyms, are among the rare eponyms that appear in theTerminologia Histologica (TH). As you recall, the TH is the "official" list of microscopic anatomy terms produced by the FICAT (Federative International Committee on Anatomical Terminology).  It is named for its discoverer Camillo Golgi, who was ridiculed for believing it to be a distinct organelle.

(For a video on international terminology that you can share with students, go to http://www.youtube.com/watch?v=94PU6J3Y9mA)

Now for the next question to be answered . . . what mechanism pulled Golgi's mustache out into that crazy handlebar shape?
 
GOLPH3 bridges phosphatidylinositol-4-phosphate and actomyosin to stretch and shape the golgi to promote budding. 
Dippold, H.C. et al. 
Cell 139 (Oct. 16) 2009. 
DOI 10.1016/j.cell.2009.07.052
[The original paper. The "supplemental material" icludes a video showing the stretching of the Golgi]

Golgi's Job Stretches it Thin
Lisa Grossman
Science News October 19, 2009
[Summary article explains the context and importance of the discovery]

[For more FREE images of the Golgi apparatus, visit the FREE Image Library at The A&P Professor website.]

Flu facts . . . the basics about H1N1

The CDC tells us that there is widespread 2009 novel H1N1 influenza activity in 41 states and that the number of cases, hospitalizations, and deaths continue to increase.
 
Many of you have begun implementing strategies on your campus to minimize the spread of the flu, including self-isolation of faculty, staff, and students with flu-like symptoms.  The CDC suggests that nearly all flu cases right now are 2009 novel H1N1 infections.

Recently, I published a brief article in a publication called The Global Pages on my home campus that lays out the basic science needed to understand what's going on.  It's not a detailed report of the current status or all the complicated virology and epidemiology involved.  It's just a basic foundation of essential terms and key concepts about viruses, public health management, and this particular flu strain.  And why it's not really "swine flu" in the strictest sense, anyway.  It's directed at the average student (not particularly science students).


I'm sharing it because it may help you answer those inevitable questions that your students may have.  Feel free to share it with your students.

Novel H1N1--A Global Health Threat
Kevin Patton
The Global Pages Vol. 10 (No. 1) Fall 2009 St. Charles Community College
[A PDF-format handout that you can read and/or share with your students.  Click here for a SWF-format file that you can embed in a PowerPoint slide or a course web page.] 
 

Action potential in action


I recently found a really nice FREE animation of the action potential. It's from Harvard's outreach program and it does a great job of breaking down the essential processes of this hard-to-learn, hard-to-teach concept.

I've just added it to my own course outline so that my students can access it easily. One might also use it during class, or a tutoring session with students, to reinforce understanding of the action potential's mechanisms. Hmmm . . . this could also be a good thing to go through with my students in my A&P 1 Supplement course, eh?
Action Potential Animation
[Interactive animation]

Action Potential Video
[Another nice, animated explanation of the action potential]

Action Potential Diagram
[A free diagram of the action potential. Compares the ideal "schematic" to a recorded action potential.]

Monday, October 12, 2009

Virtual autopsies


Wow, this goes on my wish list for the holiday season. Take a look at the Virtual Autopsy system at visualiseringscenter.se

After scanning a body, users can manipulate the images on what my editor, Jeff Downing, calls "an iPhone on steroids." It's a big table-top, touch-screen monitor that shows high-resolution 3D images of the scanned body.

The creators tout their project as a potential solution to situations where traditional autopsies cannot be performed (for example, in areas where cultural taboos prohibit it). It can also be a complement to traditional autopsies because it can show things that may not be visible during the routine type of examination.

Besides the gee-whiz, ain't that cool factor you'll experience when you check it out, you may want to consider showing one of the FREE video clips to your students to show them what's happening out there on the cutting edge of anatomy applications. This might be a great bit to add to your "first lecture" dog-and-pony show to get your students engaged and excited about human A&P.

There are also some cool case study ideas included at the demo page.

If you get one of these things, let me know. I want to come and play with it!

Visual Analogy Guides


Well, it's "book order" time here at my college and I'm going to be recommending a series of student supplements for A&P that I've found to be really, really helpful. The Visual Analogy Guide series has been used by my students for a couple of years now and my students love them.

Created by my friend Paul Krieger at Grand Rapids Community College (GRCC), the Visual Analogy Guides really meet the students where they are at to help them master some of those little tricks for learning the core concepts of an A&P course.

Using his considerable skills as an illustrator and his great talent as a teacher, Paul has put together some great tools that help students focus their study time by using visual and kinesthetic processes to help them learn "the hard parts" of A&P.

Check out his video
, in which he explains how the Visual Analogy Guides work.

Wednesday, October 7, 2009

Ribosome scientists win 2009 Nobel Prize in Chemistry


EXTRA! EXTRA! This news just in from the Royal Swedish Academy of Sciences . . .

The 2009 Nobel Prize in Chemistry has been awarded jointly to


Venkatraman Ramakrishnan
MRC Laboratory of Molecular Biology, Cambridge,
United Kingdom

Thomas A. Steitz
Yale University, New Haven, CT, USA

Ada E. Yonath
Weizmann Institute of Science, Rehovot, Israel

"for studies of the structure and function of the ribosome"

As I've mentioned in yesterday's "extra edition" of The A&P Professor, as well as in previous posts, I love to tie major awards and other news about major discoveries in the recent history of science into what we are actually learning in A&P class. And the real people behind these discoveries.

Wow, this morning's announcement for the chemistry prize couldn't have been better timed. Not long ago we wrestled with the story of protein synthesis and my students slowly realized the critical role of the ribosome's structure in that story.

An understanding of the ribosome's innermost workings is important for a scientific understanding of life. This knowledge can be put to a practical and immediate use; many of today's antibiotics cure various diseases by blocking the function of bacterial ribosomes. Without functional ribosomes, bacteria cannot survive. This is why ribosomes are such an important target for new antibiotics.

This year's Nobel Laureates in Chemistry have all generated 3D models that show how different antibiotics bind to the ribosome. These models are now used by scientists in order to develop new antibiotics, directly assisting the saving of lives and decreasing humanity's suffering.

This gives us an opportunity to show how understanding the "basic science" that are teaching translates (ahem) into applications in "the real world."

Want to know more?

"Public" summary
[PDF article intended for the general reader; does a good job of recapping the role of the ribosome within the big picture of biology, includes some nice graphics that you can use in your class plus links for further reading]

Scientific Background
[PDF article directed at those of use with some science background; well-written summary of the ribosome and the evolution of scientific discovery leading to the awarding of this prize; includes some good graphics; comprehensive list of scientific references]


Other resources

Nobel's "useful links and further reading"

FREE image of ribosome's role in translation

FREE image of detailed ribosome structure

Additional FREE ribosome images

NOTE: I apologize to my email subscribers who received two posts yesterday instead of one. I've adjusted the timing so you should only get one delivery on these rare occasions when I have an "immediate" post to send to you.

{Some content of this post came from the Nobel organization}


Monday, October 5, 2009

2009 Nobel Prize in Physiology or Medicine

I love the sense of awe that I get on those brisk Monday mornings in October when NPR announces the first of the Nobel Prizes . . . the prize for Physiology or Medicine. I'm struck by the truly groundbreaking nature of the discoveries that win prizes. No less this year, with the prize going jointly to three U.S. scientists for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.

We've recently covered the whole molecular genetics/protein synthesis/cell life cycle suite in our A&P class . . . so my students will be ready to hear about the concepts for which the prize was awarded today. I like to show them that science is dynamic and evolving, with new discoveries made every day. These "big" announcements further underscore that what they are learning is fresh and relevant.

Hmmm . . . this gives me an idea for a bonus question on the midterm exam!

Today, I have a special longer post today, so that you can walk into the classroom TODAY ready to discuss what some of them may have already heard about. If you stick with me until the end, I have a link to an image that you can use TODAY in your class!

This year's Nobel Prize in Physiology or Medicine is awarded to three scientists who have solved a major problem in biology: how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation. The Nobel Laureates have shown that the solution is to be found in the ends of the chromosomes – the telomeres – and in an enzyme that forms them – telomerase.

The long, thread-like DNA molecules that carry our genes are packed into chromosomes, the telomeres being the caps on their ends. Elizabeth Blackburn and Jack Szostak discovered that a unique DNA sequence in the telomeres protects the chromosomes from degradation. Carol Greider and Elizabeth Blackburn identified telomerase, the enzyme that makes telomere DNA. These discoveries explained how the ends of the chromosomes are protected by the telomeres and that they are built by telomerase.

If the telomeres are shortened, cells age. Conversely, if telomerase activity is high, telomere length is maintained, and cellular senescence is delayed. This is the case in cancer cells, which can be considered to have eternal life. Certain inherited diseases, in contrast, are characterized by a defective telomerase, resulting in damaged cells. The award of the Nobel Prize recognizes the discovery of a fundamental mechanism in the cell, a discovery that has stimulated the development of new therapeutic strategies.

The mysterious telomere

The chromosomes contain our genome in their DNA molecules. As early as the 1930s, Hermann Muller (Nobel Prize 1946) and Barbara McClintock (Nobel Prize 1983) had observed that the structures at the ends of the chromosomes, the so-called telomeres, seemed to prevent the chromosomes from attaching to each other. They suspected that the telomeres could have a protective role, but how they operate remained an enigma.

When scientists began to understand how genes are copied, in the 1950s, another problem presented itself. When a cell is about to divide, the DNA molecules, which contain the four bases that form the genetic code, are copied, base by base, by DNA polymerase enzymes. However, for one of the two DNA strands, a problem exists in that the very end of the strand cannot be copied. Therefore, the chromosomes should be shortened every time a cell divides – but in fact that is not usually the case (Fig 1).

Both these problems were solved when this year's Nobel Laureates discovered how the telomere functions and found the enzyme that copies it.

Telomere DNA protects the chromosomes

In the early phase of her research career, Elizabeth Blackburn mapped DNA sequences. When studying the chromosomes of Tetrahymena, a unicellular ciliate organism, she identified a DNA sequence that was repeated several times at the ends of the chromosomes. The function of this sequence, CCCCAA, was unclear. At the same time, Jack Szostak had made the observation that a linear DNA molecule, a type of minichromosome, is rapidly degraded when introduced into yeast cells.

Blackburn presented her results at a conference in 1980. They caught Jack Szostak's interest and he and Blackburn decided to perform an experiment that would cross the boundaries between very distant species (Fig 2). From the DNA of Tetrahymena, Blackburn isolated the CCCCAA sequence. Szostak coupled it to the minichromosomes and put them back into yeast cells. The results, which were published in 1982, were striking – the telomere DNA sequence protected the minichromosomes from degradation. As telomere DNA from one organism, Tetrahymena, protected chromosomes in an entirely different one, yeast, this demonstrated the existence of a previously unrecognized fundamental mechanism. Later on, it became evident that telomere DNA with its characteristic sequence is present in most plants and animals, from amoeba to man.


An enzyme that builds telomeres

Carol Greider, then a graduate student, and her supervisor Blackburn started to investigate if the formation of telomere DNA could be due to an unknown enzyme. On Christmas Day, 1984, Greider discovered signs of enzymatic activity in a cell extract. Greider and Blackburn named the enzyme telomerase, purified it, and showed that it consists of RNA as well as protein (Fig 3). The RNA component turned out to contain the CCCCAA sequence. It serves as the template when the telomere is built, while the protein component is required for the construction work, i.e. the enzymatic activity. Telomerase extends telomere DNA, providing a platform that enables DNA polymerases to copy the entire length of the chromosome without missing the very end portion.

Telomeres delay ageing of the cell

Scientists now began to investigate what roles the telomere might play in the cell. Szostak's group identified yeast cells with mutations that led to a gradual shortening of the telomeres. Such cells grew poorly and eventually stopped dividing. Blackburn and her co-workers made mutations in the RNA of the telomerase and observed similar effects in Tetrahymena. In both cases, this led to premature cellular aging – senescence. In contrast, functional telomeres instead prevent chromosomal damage and delay cellular senescence. Later on, Greider's group showed that the senescence of human cells is also delayed by telomerase. Research in this area has been intense and it is now known that the DNA sequence in the telomere attracts proteins that form a protective cap around the fragile ends of the DNA strands.

An important piece in the puzzle – human aging, cancer, and stem cells

These discoveries had a major impact within the scientific community. Many scientists speculated that telomere shortening could be the reason for aging, not only in the individual cells but also in the organism as a whole. But the aging process has turned out to be complex and it is now thought to depend on several different factors, the telomere being one of them. Research in this area remains intense.

Most normal cells do not divide frequently, therefore their chromosomes are not at risk of shortening and they do not require high telomerase activity. In contrast, cancer cells have the ability to divide infinitely and yet preserve their telomeres. How do they escape cellular senescence? One explanation became apparent with the finding that cancer cells often have increased telomerase activity. It was therefore proposed that cancer might be treated by eradicating telomerase. Several studies are underway in this area, including clinical trials evaluating vaccines directed against cells with elevated telomerase activity.

Some inherited diseases are now known to be caused by telomerase defects, including certain forms of congenital aplastic anemia, in which insufficient cell divisions in the stem cells of the bone marrow lead to severe anemia. Certain inherited diseases of the skin and the lungs are also caused by telomerase defects.

In conclusion, the discoveries by Blackburn, Greider and Szostak have added a new dimension to our understanding of the cell, shed light on disease mechanisms, and stimulated the development of potential new therapies.

Elizabeth H. Blackburn has US and Australian citizenship. She was born in 1948 in Hobart, Tasmania, Australia. After undergraduate studies at the University of Melbourne, she received her PhD in 1975 from the University of Cambridge, England, and was a postdoctoral researcher at Yale University, New Haven, USA. She was on the faculty at the University of California, Berkeley, and since 1990 has been professor of biology and physiology at the University of California, San Francisco.

Carol W. Greider is a US citizen and was born in 1961 in San Diego, California, USA. She studied at the University of California in Santa Barbara and in Berkeley, where she obtained her PhD in 1987 with Blackburn as her supervisor. After postdoctoral research at Cold Spring Harbor Laboratory, she was appointed professor in the department of molecular biology and genetics at Johns Hopkins University School of Medicine in Baltimore in 1997.

Jack W. Szostak is a US citizen. He was born in 1952 in London, UK and grew up in Canada. He studied at McGill University in Montreal and at Cornell University in Ithaca, New York, where he received his PhD in 1977. He has been at Harvard Medical School since 1979 and is currently professor of genetics at Massachusetts General Hospital in Boston. He is also affiliated with the Howard Hughes Medical Institute.

Want a high-resolution image that you can use in your class TODAY to illustrate the discovery for which today's Nobel Prize was given? Just click here.



Want to know more?

Video of the Nobel Prize announcement

Video of interview after the announcement explaining the story behind the discovery

Press Release on the award

[The above resources also have links to interviews with these Nobel laureates and photos of them and their work.]


Original Journal References:

Cloning yeast telomeres on linear plasmid vectors.
Szostak JW, Blackburn EH.
Cell 1982; 29:245-255.

Identification of a specific telomere terminal transferase activity in Tetrahymena extracts.
Greider CW, Blackburn EH.
Cell 1985; 43:405-13.

A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis.
Greider CW, Blackburn EH.
Nature 1989; 337:331-7.

[Some of the material in this article came from a press release from the Nobel organization.]

Sunday, October 4, 2009

FREE nerve signaling activity

The Nobel Prize site has a nice animated "game" that goes through the basics of nerve signaling.  It features explanatory text alongside some nifty, simplified diagrams that are animated.

The level of coverage may be sufficient for some courses . . . but if not, then it's a good preview or review, which will help students see how it all fits together.

Try it out at Nerve Signaling.

Here's a brief video introducing this FREE online activity for your students.



Keep up with this blog on your phone

The A&P Professor blog is now available on your mobile device!

Check it out at http://theapprofessor.mofuse.mobi/

Even if you prefer to view the blog at the Blogger interface or Facebook or the free email newsletter, you might find that being able to browse (or quickly find a reference) on your iPhone, BlackBerry, or other smartphone is a handy thing to be able to do.

Sunday, September 13, 2009

FREE anatomic bookmarks for your students

To help you help your students, I'm still offering those FREE "anatomical eyeball" bookmarks for your students!

Some of you have already received and distributed yours. But the rest of you should act now . . . while supplies last!

The bookmark is a whopping 2" by 7" printed on thick card stock—not one of those wimpy little bookmarks others give away. OK, nobody else gives away such anatomical bookmarks (as far as I know) but this is an unusually large size for a bookmark.

On the obverse side is an anatomically correct rendering of an eyeball in its bony orbit on the (anatomical) right and the eyeball partly covered by the palpebrae (lids) on the left. When you distribute them to your class, you might even take the opportunity to quiz them on anatomical directions (anatomical left and right vs. the viewer's left and right) to hone some skills, eh?

The reverse side contains information about The A&P Student blog.

The blog is mainly aimed at undergraduate college students but is also useful for high school students and even students in professional studies (medicine, allied health, etc.).

Just email me at kevin@theAPprofessor.org and tell me how many packs of 50 bookmarks you need for your class. And tell me where to send it (it MUST be a school address).

But wait!

That's not all!

Act now, and I'll throw in a few FREE humerus bookmarks for your own use!

That's right! These anatomic bookmarks (of the same sturdy structure as the eyeball bookmarks) feature a human humerus on one side and The A&P Professor hip logo on the other side.

You can use them yourself . . . and have some spares to share with your colleagues.

So, again, email me NOW at kevin@theAPprofessor.org and tell me how many packs of 50 bookmarks you need for your class. And tell me where to send it (it MUST be a school address).

Virtual Microscope (and other FREE stuff)


Have you ever been to the Blue Histology website? Produced by the School of Anatomy and Human Biology at the University of Western Australia, and sponsored by Olympus, this site is chock full of excellent histology images (often at several magnifications) that you and your students can use for FREE.

One of the nifty features at Blue Histology is their VScope which is a virtual microscope that can help students figure out some basic things about changing magnifications, using the diaphragm, and other essential skills for light microscopy.

They assert that their VScope is not an ideal simulator of the real microscopy experience, even going so far as to intentionally mispel the title of their project as "Vurtial Microscope." And it's not ideal, especially with an old computer and slow connection speed. But it's still pretty cool and still good for some "at home" exploration when an actual microscope is not available.

Check it out at http://www.lab.anhb.uwa.edu.au/mb140/

Sunday, September 6, 2009

Inflammation images


Some interesting images of the inflammation seen in early stages of rheumatoid arthritis (RA) were released recently.

These images use a special type of fluorescent dye that is activated by the infrared radiation released at the site of inflammation. The intent of the project is to develop a way to detect such inflammation at an early stage of RA, when there's still time to help avert some of the damage produced by this condition.

However, the images can be useful in your A&P course when discussing the process of inflammation. The images are a dramatic example that contrasts the heat present in a normal hand versus the heat produced by hands that are inflamed.

To access the images go to:
Rheumatism Video Discloses Center Of Inflammation At An Early Stage.
Physikalisch-Technische Bundesanstalt (PTB) (2009, August 29).
ScienceDaily. Retrieved August 30, 2009
[Press release with associated images. Be sure to click the images for the larger view.]

High-fat diets may reduce muscle and cognitive abilities within days

Recent research at the University of Cambridge shows that rats fed on a high-fat diet have markedly reduced muscle and cognitive function within a few days of a change to the high-fat diet, compared to rats fed on a low-fat diet.

The results were reported in The FASEB Journal recently and summarized in a press release published at Science Daily.

Of course, this happened in lab rats . . . not humans.  So we have a long way to go before we can establish specific human nutritional guidelines.  And the low-fat diets were very low, compared the average American diet.  But the high-fat diet fed to rats approached that consumed by many who eat mostly junk food . . . and some on high-fat, low-carb diets (however, the high-fat rat diet wasn't particularly low in carbs).  

Even though there are more questions to answer, these results are remarkable and may prove to be an important milestone in understanding human metabolism.  And may someday affect how athletes prepare for competitions . . . and now students prepare for exams.

For example, researchers claim that the high-fat diet changes the expression of the UCP3 (uncoupling protein) gene.  UCP3 "uncouples" oxidative phosphorylation from ATP synthesis by allowing protons to "leak" across the inner mitochondrial membrane, thus disrupting the proton gradient that drives ATP synthase. (Chapter 27 in my Anatomy & Physiology textbook illustrates the normal function of the proton gradient.) 

Such respiratory uncoupling would explain the reduced physical and cognitive ability seen in the experiments. This could be a very useful trail to follow, eh?

Want to know more?

Do High-fat Diets Make Us
Stupid And Lazy? Physical And Memory Abilities Of Rats Affected After 9
Days.

University of Cambridge (2009, September 5).
ScienceDaily. Retrieved September 6, 2009
[Plain English summary of the results and their implications]


Deterioration of physical performance and cognitive function in rats with short-term high-fat feeding.
Murray et al.
The FASEB Journal, 2009; DOI: 10.1096/fj.09-139691
[FREE abstract of the original research article]

{Photo taken by Muu-karhu
}



Monday, August 31, 2009

Genome book


I think everyone, including all A&P students, should be up to date on the major concepts of genetics and genomics. In most A&P courses, we don't have much (if any) time to cover the basics . . . I think most of us just assume that they've picked it all up in their prerequisite course(s). Or maybe simply by osmosis?

The way I handle it is to cover some of the basics in the section on molecular genetics when we cover cell structure and function. But a lot of it I cover in "extra credit" assignments over the course of both semesters.

One of the centerpieces of these projects is a guided reading of Matt Ridley's book Genome: The Autobiography of a Species in 23 Chapters
.


The current (revised) edition (called the "P.S." edition) has been out a few years now, but still retains its up-to-date quality.

It's meant as an introduction to genetics and genomics for the general reading audience but it is a perfect way to introduce beginning A&P students to the principles that they will need to know as they proceed through their training and into their professions.

Each of the 23 chapters looks at one of the pairs of human chromosomes. Each chapter does not discuss the whole chromosome. Instead, Ridley picks out one or two essential principles that the structure or function of that chromosome can be used to illustrate.

Not only is Ridley able to explain the central genetic principles in an easily understood way, he is also able to do it mostly through stories rather than dry, technical descriptions and definitions.

If you haven't read it yet, you should. And if you haven't figured out a way to get your students to read it . . . well, then try my method. I give them additional points toward their course grades for reading the book and answering online test questions about each chapter.

For the description of the project, go to www.lionden.com/ap1_genome_x.htm

For a list of discussion questions to guide their reading of each chapter (that you are welcome to link to) go to www.lionden.com/ap1_genome_q.htm

Let me know what you think of the book!

Street Anatomy blog


I ran across this crazy and interesting blog the other other day and thought I'd share it with you. It's called Street Anatomy and it "obsessively covers the use of human anatomy in medicine, art, and design."

It has some fantastic, gross, insane, and interesting examples of human anatomical art that you might want to use to spice up your classroom presentation.

For example, I was looking for an example of a tattoo that I could use in my presentation on the skin and found the Street Anatomy gallery of anatomical tattoos. Check it out: http://streetanatomy.com/galleries/anatomy-tattoo-gallery/

For the latest entry in the Street Anatomy blog, go to

Monday, August 24, 2009

The A&P Student blog


Way back in January I told you about my blog to assist A&P students as they struggle through the course . . . The A&P Student.

Well, as many of us begin a new academic year, with all new students, this might be a good time to remind our students that they CAN find shortcuts and tips for success if they look for them . . . and an easy place to look is The A&P Student blog.

You are welcome to link to the blog from your online syllabus, your course webpage (including Blackboard, Angel, etc.), or post it on the classroom bulletin board.

The blog features study tips, test-taking strategies, hints for using their textbook more effectively, and more. The conversational, occasionally silly, tone of the blog will engage students looking for more efficient ways to learn A&P . . . or tips on simply surviving.

Please pass the information along to your students and colleagues. You are welcome to link to the blog from your online syllabus, your course webpage (including Blackboard, Angel, etc.), or post it on the classroom bulletin board.
The A&P Student blog
http://theAPstudent.blogspot.com

The A&P Student newsletter

http://theAPstudent.feedblitz.com

The A&P Student on Facebook
http://www.facebook.com/pages/The-AP-Student/90694738693
To help you help your students, I'm offering some FREE "anatomical eyeball" bookmarks for your students! While supplies last!

The bookmark is a whopping 2" by 7" printed on thick card stock—not one of those wimpy little bookmarks others give away.

On the obverse side is an anatomically correct rendering of an eyeball in its bony orbit on the (anatomical) right and the eyeball partly covered by the palpebrae (lids) on the left. When you distribute them to your class, you might even take the opportunity to quiz them on anatomical directions (anatomical left and right vs. the viewer's left and right) to hone some skills, eh?

The reverse side contains information about The A&P Student blog.

The blog is mainly aimed at undergraduate college students but is also useful for high school students and even students in professional studies (medicine, allied health, etc.).

Just email me at kevin@theAPprofessor.org and tell me how many packs of 50 bookmarks you need for your class. And tell me where to send it (it MUST be a school address).

New "old" news about the appendix


A recent article in ScienceDaily discusses a new article in the Journal of Evolutionary Biology regarding the evolution of the human appendix.

As you know, Darwin thought that the vermiform appendix was a vestigial, nonfunctional structure "left over" from our evolutionary past.

And if you been using my A&P textbooks for the last ten years or so, you also know that biologists have long suspected (and recently confirmed) that the appendix is no such thing. Its function is to incubate intestinal flora (gut bacteria)—which helps keep the ecosystem of the gut in a healthy balance by repopulating the colon with beneficial bacteria after an illness or other disturbance.

The new journal article, written by some of the same researchers involved in the most recent confirmation of the "incubator model of the appendix," tackles the evolutionary aspects of the appendix.

Want to know more?

Evolution Of The Human Appendix: A Biological 'Remnant' No More.
Duke University Medical Center
ScienceDaily Duke University Medical Center. 21 August 2009.
[Summary of the journal article and its context]
Comparative anatomy and phylogenetic distribution of the mammalian cecal appendix
Smith, et al.Journal of Evolutionary Biology. published online 12 August 2009
[Abstract of the journal article, published in advance of the print version]


Click here for a FREE surgical photo of a human vermiform appendix.

Wednesday, August 12, 2009

Doing our part to reduce medical errors


Something to think about as we begin a new academic year teaching future health professionals:
Deaths from avoidable medical error more than double in past decade, investigation shows
Katherine Harmon
60-Second Science Blog 10 August 2009
I don't know about you . . . but I sometimes have the chilling thought that I will someday awake from an unconscious state in an emergency room somewhere and one of my former students will be smiling at me and say, "don't worry Kevin, I'll be taking care of you" . . . and it's someone who failed my class because they couldn't tell a femur from a fibula.

So I guess that now's a good time to remind ourselves why we are sometimes as hard-nosed as we are about our students know their stuff (and spelling it correctly). Because someday, they'll be posting things to OUR medical records and they'd better not be typing in perineum when they mean peritoneum!


Case Study Teaching Conference


This just in from the National Center for Case Study Teaching in Science . . .

Register today and take advantage of the early bird special rate for our case study teaching conference. We are excited to present three informative tracks at this year's conference, culminating in a final session delivered by Deborah Allen from the NSF: Writing More Effective Proposals for NSF's Course, Curriculum & Laboratory Improvement Program. Based on your feedback this year’s conference will focus (in addition to our beginner track) on the following areas:

ASSESSMENT - Diane Ebert-May, a national specialist on assessment, will be delivering a plenary on “Moving Beyond Assessment to Research” as well as a break-out session on “Teaching for Understanding in Science: Active Learning and Assessment.”

HIGH SCHOOL TEACHERS - A new “mini” track made up of three sessions on Saturday specifically designed for high school science teachers (though others, we think, will find it of interest too!). Our break-out session leaders are Richard Donham, Senior Policy Associate, Mathematics & Science Education Resource Center, University of Delaware, and James Serach, Aldo Leopold Chair for Distinguished Teaching of Environmental Science and Ethics, The Lawrenceville School.

CLICKER CASES - A new “mini” track on what we call “clicker cases.” We have been getting a lot of questions about how we are using personal response systems (aka clickers) with case studies to create rich and student-active learning environments in large introductory science courses (though the method works well in any size classroom!). There are three sessions in this track, which runs on Saturday.

FINAL SESSION FOR ALL: Many of you have requested information on writing your own grants related to case studies. We are pleased that Deborah Allen, Program Director, Division of Undergraduate Education, National Science Foundation, will be conducting a session for us this fall entitled, Writing More Effective Proposals for NSF's Course, Curriculum & Laboratory Improvement Program. A description of the session can be found at: http://ublib.buffalo.edu/libraries/projects/cases/conference/schedule.html

Our conference will be led by Dr. Clyde (Kipp) Herreid, SUNY Distinguished Teaching Professor and Director of the National Center for Case Study Teaching in Science. The conference is open to anyone interested in science education including high school teachers and international teachers. See below for a full listing of the conference sessions and other information. Our conference also includes a poster session and we would be pleased if you submitted a proposal.

Register now for this exciting 2-day Case Study Teaching in Science Conference, which takes place on September 25th and 26th, 2009. Early-Bird two-day registration until September 1, 2009 - $450.00. One-day Saturday-only registration is $350.

Wednesday, August 5, 2009

Can a borrow a cup of copernicium?


Last month, I gave you the heads-up on the newly confirmed element 112. Now, we have a proposed name for it . . . Copernicium (Cp).

An eponym for the 16th-century Polish scholar Nicolaus Copernicus (pictured)—the guy widely known for his ground-breaking heliocentric view of cosmology—the new name is not yet official. Copernicium is the name proposed by the discoverers . . . and that usually becomes the official name unless somebody finds out it means something nasty in some human language somewhere.

This eponym thing is interesting. In human anatomy, we are shunning eponyms—in chemistry, it seems to be embraced. Hmmm. And get this . . . Nick Copernicus's name is in fact adopted from the name of element 29, copper (Cu). The name is the Latinized form of Mikołaj Kopernik—his surname having been based on his family's business (copper work).

So tuck that away in your trivia file, eh?

Click here for more information.

Vitamin D is hot


A recent article in the LA Times quotes a nutrition professor that "vitamin D is one hot topic." This week an Institute of Medicine committee meets to determine whether the recommended daily intake of vitamin D (and calcium) should be increased. And apparently, there is a LOT of recent research on this topic that says YES! (over 2,000 articles just this year)

The research suggests that besides its well-known effects on calcium absorption, vitamin D may also affect many types of cell functions throughout the body.

Want to know more?

It may be vitamin D's day in the sun
Shari Roan
Los Angeles Times August 1, 2009
[Summary article]

Vitamin D articles
Annals of Epidemiology July 2009 Volume 19, Issue 7
[Collection of FREE journal articles about Vitamin D's health effects]

{The image above from Ragesoss is a FREE image showing supplements containing calcium and Vitamin D}

FREE herniated disc video

There's a new FREE video available from one of my favorite medical/anatomical animation producers Nucleus Medical Art.

Even if you don't care to discuss the herniation aspect, it's a nice animation showing the location and basic structure of an intervertebral disc.

Check out the other videos from Nucleus, many of which you might be able to use in your A&P course.


[If you don't see the video viewer in your newsletter or feed version of this article, please go to The A&P Professor blog site to view it. Want to learn how to embed YouTube videos in your blog, website, or Powerpoint? Check it out at The A&P Professor website.]