And here is the de Waal's podcast on chimpanzees and bonobos.
Wednesday, April 28, 2010
Evolution of human behavior
Here are links for the books and the podcast I mentioned in class today. Our AU library has the following books:
Wednesday, March 31, 2010
What's up with yawning
A quick search of the science blogosphere hit on the main hypotheses for why we yawn? The cited blog posts below will lead you to the primary literature if you need it.
Common wisdom, and common sense, suggests that we yawn when we are tired because we are not getting enough oxygen and building up too much CO2. However, like many elegant and simple hypotheses this one appears to be wrong. The data suggest that gas content does not influence yawning. We apparently do yawn more when bored, but this is not tied to slower breathing.
A relatively newer hypothesis suggests that we yawn to cool our brain when it gets to warm. The idea is that the increased air flow will cool an overheated brain, as long as external temperatures are not too hot. This idea has been tested in birds and seems to be supported by the data.
And yawning is contagious (I am yawning know - OK, a stale joke I found in all the yawning blog posts I read), at least in primates. But interestingly, yawning is less common in humans with autism disorders, perhaps because they do not pick up on the social cue that others are yawning. This social yawning response may be some sort of empathy behavior, and perhaps evolved due to some benefit of group yawning. But it is unclear what that benefit would be. Maybe if one member of the group has an overheated brain, everyone else probably does as well?
Yawning also seems linked to multiple human diseases - when you have these diseases you yawn more. The mechanism behind this is unclear.
It is amazing that such a common behavior could remain such a mystery.
Common wisdom, and common sense, suggests that we yawn when we are tired because we are not getting enough oxygen and building up too much CO2. However, like many elegant and simple hypotheses this one appears to be wrong. The data suggest that gas content does not influence yawning. We apparently do yawn more when bored, but this is not tied to slower breathing.
A relatively newer hypothesis suggests that we yawn to cool our brain when it gets to warm. The idea is that the increased air flow will cool an overheated brain, as long as external temperatures are not too hot. This idea has been tested in birds and seems to be supported by the data.
And yawning is contagious (I am yawning know - OK, a stale joke I found in all the yawning blog posts I read), at least in primates. But interestingly, yawning is less common in humans with autism disorders, perhaps because they do not pick up on the social cue that others are yawning. This social yawning response may be some sort of empathy behavior, and perhaps evolved due to some benefit of group yawning. But it is unclear what that benefit would be. Maybe if one member of the group has an overheated brain, everyone else probably does as well?
Yawning also seems linked to multiple human diseases - when you have these diseases you yawn more. The mechanism behind this is unclear.
It is amazing that such a common behavior could remain such a mystery.
Thursday, March 18, 2010
The search for an HIV vaccine . . . and a blood update
Check out this opinion article from Nature on the development of an HIV vaccine. We will talk about it in lecture next Monday. (You will need to be on campus to have access to this article. Print it out if you need to read it from off campus.)
And this may be shameless self-promotion, but you might be interested in reading two recent blog posts of mine on blood stem cells (here and here). Not required reading, but they are there if you are interested.
And this may be shameless self-promotion, but you might be interested in reading two recent blog posts of mine on blood stem cells (here and here). Not required reading, but they are there if you are interested.
Tuesday, February 16, 2010
Hemophilia, an update
We left class Monday with lots of good questions about hemophilia. Well, here are some answers, sources for additional information, and some cool new papers.
There are two types of hemophilia, depending on which of two clotting factors genes are mutated. The more common hemophilia A is due to a lack of clotting factor VIII, while hemophilia B is due to mutation of the clotting factor IX gene. Both genes are on the X-chromosome, and can be passed down from the parents (usually the Mother to the son), but can also be caused by new mutations in the genes. Why do these mutations only occur in these two genes? I don't know.
Hemophilia can be treated prophylactically by injecting the missing clotting factor before it is needed, or can be injected only when needed. The proteins can be purified from human plasma, or can be made recombinantly in the lab. And how do physicians know what type of hemophilia a patient has? Apparently there is a simple blood test that determines which factor is missing.
Check out this case study on a patient with both leukemia and hemophilia. We will talk about it in class next week.
And here is a very interesting paper on the effect of blood flow rate on the activation of clotting factors. One figure from our text book shows two pathways for the activation of clotting factors, one stimulated by the damaged cardiovascular tissue, and the other by the platelets. But the flow rate of the blood can also regulate the factors, through the activity of factor Xa. When blood flow rate is low, factor Xa activates factor VII. The authors conclude that this mechanism helps to prevent unnecessary coagulation in flowing blood, and may explain why pooling blood will clot.
There are two types of hemophilia, depending on which of two clotting factors genes are mutated. The more common hemophilia A is due to a lack of clotting factor VIII, while hemophilia B is due to mutation of the clotting factor IX gene. Both genes are on the X-chromosome, and can be passed down from the parents (usually the Mother to the son), but can also be caused by new mutations in the genes. Why do these mutations only occur in these two genes? I don't know.
Hemophilia can be treated prophylactically by injecting the missing clotting factor before it is needed, or can be injected only when needed. The proteins can be purified from human plasma, or can be made recombinantly in the lab. And how do physicians know what type of hemophilia a patient has? Apparently there is a simple blood test that determines which factor is missing.
Check out this case study on a patient with both leukemia and hemophilia. We will talk about it in class next week.
And here is a very interesting paper on the effect of blood flow rate on the activation of clotting factors. One figure from our text book shows two pathways for the activation of clotting factors, one stimulated by the damaged cardiovascular tissue, and the other by the platelets. But the flow rate of the blood can also regulate the factors, through the activity of factor Xa. When blood flow rate is low, factor Xa activates factor VII. The authors conclude that this mechanism helps to prevent unnecessary coagulation in flowing blood, and may explain why pooling blood will clot.
Monday, February 15, 2010
Regenerative medicine in Ohio
We will be hosting a guest speaker in class this Friday - Mr. Read Wakefield, the director of the Morgan Center for Entrepreneurship, will talk to us about the business side of biotechnology. How exactly do people know that there will be a need and market for a research find or medical innovation? To prepare for his visit, I would like you to watch a video of Elizabeth Sump, the Executive Director of the Clinical Tissue Engineering Center at the Cleveland Clinic.
Ms. Sump gives a great talk on the extensive work being done in regenerative medicine in the Northeast Ohio region. In particular, she talks about the economic cost of congestive heart failure, and why investing in treatments for this disorder make economic sense. This talk is not only a good review of physiology topics we will cover in class, but will set us up for our discussion with Mr. Wakefield.
The video is about 42 minutes long, and I encourage you to watch it all. But be sure to watch at least the first 27 minutes.
Ms. Sump gives a great talk on the extensive work being done in regenerative medicine in the Northeast Ohio region. In particular, she talks about the economic cost of congestive heart failure, and why investing in treatments for this disorder make economic sense. This talk is not only a good review of physiology topics we will cover in class, but will set us up for our discussion with Mr. Wakefield.
The video is about 42 minutes long, and I encourage you to watch it all. But be sure to watch at least the first 27 minutes.
Friday, February 12, 2010
Medical Innovation Ideas
Synvisc-One
Synvisc-One is a way to treat osteoarthritis (OA) knee pain right at the source. In OA, the synovial fluid breaks down and can no longer provide cusion at your knee joint. Synvisc-One, a synthetic substance, is injected into your joint and mimics the cusion and lubrication of a healthy joint.
The Electric Eye
MIT researchers are developing a microchip that will partially restore eyesite to the blind. They will not have clear vision but will be able to recognize faces, see shadows, and navagate through a room by themselves. The chip, which works insync with a special pair of glasses the patients must wear, will be implanted into the eye. A timy camera, in the glasses, will transmit images directly to the chip and straight on to the brain.
Lyric Hearing Aid
The Lyric Hearing Aid is a major upgrade from a regular hearing aid in that it is completely invisible (being placed deep inside the ear canal, one-sixth of an inch from the eardrum), it does not have to be removed to shower or sleep, and does not overamplify noises. Although it can be worn 24 hours a day, it needs to be removed and replaced 3 to 4 times a year.
Synvisc-One is a way to treat osteoarthritis (OA) knee pain right at the source. In OA, the synovial fluid breaks down and can no longer provide cusion at your knee joint. Synvisc-One, a synthetic substance, is injected into your joint and mimics the cusion and lubrication of a healthy joint.
The Electric Eye
MIT researchers are developing a microchip that will partially restore eyesite to the blind. They will not have clear vision but will be able to recognize faces, see shadows, and navagate through a room by themselves. The chip, which works insync with a special pair of glasses the patients must wear, will be implanted into the eye. A timy camera, in the glasses, will transmit images directly to the chip and straight on to the brain.
Lyric Hearing Aid
The Lyric Hearing Aid is a major upgrade from a regular hearing aid in that it is completely invisible (being placed deep inside the ear canal, one-sixth of an inch from the eardrum), it does not have to be removed to shower or sleep, and does not overamplify noises. Although it can be worn 24 hours a day, it needs to be removed and replaced 3 to 4 times a year.
Medical Innovations-Danielle, Lucas and David
Here are our three options for our Wikipedia page on medical innovations
Diaphragm Pacing System- This device is for people with spinal cord injuries high enough that they need to be on a respirator. As you may or may not know, these respirators are very debilitating because they are so large. The idea of the diaphragm pacing system is to control the diaphragm via the phrenic nerve and allow these people to be mobile without the hassle of a large respirator.
Triage Tech to Capture Vitals from a Distance- This device is being studied by the US Department of Homeland Security. Triage is the act of assessing individuals to determine the severity of their injuries and decide how quickly they need to be treated. The idea behind this triage technology is to allow a person's vitals to be taken from several feet away by scanning them. This would be used in hospitals and ERs to reduce time lost when treating multiple injuries. Triage usually takes about 3 minutes but with this new scanner it could be done in a matter of seconds!
Tools for Non-Invasive Space Surgery- A company based in Akron, Ohio is currently working with NASA to create tools that could be used for non-invasive surgery in space. The information was vague but we are optimistic that the company will be open to answering our questions!
Diaphragm Pacing System- This device is for people with spinal cord injuries high enough that they need to be on a respirator. As you may or may not know, these respirators are very debilitating because they are so large. The idea of the diaphragm pacing system is to control the diaphragm via the phrenic nerve and allow these people to be mobile without the hassle of a large respirator.
Triage Tech to Capture Vitals from a Distance- This device is being studied by the US Department of Homeland Security. Triage is the act of assessing individuals to determine the severity of their injuries and decide how quickly they need to be treated. The idea behind this triage technology is to allow a person's vitals to be taken from several feet away by scanning them. This would be used in hospitals and ERs to reduce time lost when treating multiple injuries. Triage usually takes about 3 minutes but with this new scanner it could be done in a matter of seconds!
Tools for Non-Invasive Space Surgery- A company based in Akron, Ohio is currently working with NASA to create tools that could be used for non-invasive surgery in space. The information was vague but we are optimistic that the company will be open to answering our questions!
Medical Innovations- Melissa, Hallie, Amy
These are a few of the innovation topics that we found interesting and may want to study further:
The Inflatable Lifesaver:
http://www.technologyreview.
Balloon based device that can be inserted into a deep wound to stanch blood loss of serious wounds.
Made of polyurethane coated nylon .
From Cardiocommand, Tampa Fl.
Natural orifice
http://etd.ohiolink.edu/send-pdf.cgi/Schomisch%20Steve%20J.pdf?acc_num=csu1251915281
http://www.springerlink.com/content/u12853640983346j/
Transgastric Natural Orifice Translumenal Endoscopic Surgery (NOTES) procedures : a hybrid approach with a minimal laparoscopic component allowing a very controlled gastrotomy creation and closure. This technique would also allow laparoscopic suturing through a single, small cannula.
P. Swain and C. A. Mosse are consultants for Ethicon EndoSurgery, Cincinnati, Ohio, USA.
Bone Conduction of Sound For Single-Sided Deafness
http://www.clevelandclinic.org/innovations/summit/topten10/one.html
Continuous-Flow Ventricular Assist Devices
http://www.clevelandclinic.org/innovations/summit/topten10/three.html
Non-Vitamin K Antagonist Oral Anticoagulants
http://www.clevelandclinic.org/innovations/summit/topten10/four.html
Wednesday, February 10, 2010
Translational medicine and cancer
Nature has an interesting article on a British cancer researcher that emphasizes translational research, the use of basic research findings to develop clinical treatments. Alan Ashworth argues that a focus on translational research can help direct bench work, and that using discoveries to help patients makes the research even more personally valuable.
The article also gives some interesting background into Ashworth's approach to specifically targeting cancer cells by taking advantage of their reduced ability to repair DNA damage.
Monday, February 8, 2010
Linking research and business
The Chronicle's Wired Campus blog describes a new YouTube channel being used by the University of Maryland at Baltimore to make research more visible to businesses that may be interested in investing in further research and product development.
The blog post also mentions a broadly used platform for networking between researchers and business called ibridge.
The blog post also mentions a broadly used platform for networking between researchers and business called ibridge.
Friday, February 5, 2010
Testosterone changes behavior - in a good way?
You may know of the stereotype of the testosterone filled dude kicking sand in some scrawny guys face on the beach. And of course anabolic steroids (which mimic endogenous testosterone) have done wonders for the image of baseball and many other sports. But can one hormone produce changes in complex human behaviors, and could testosterone actually produce a "positive" change in behavior? According to a new paper in Nature, the answers are yes and yes.
Ernst Fehr, an economist from the University of Zurich, set up an experiment in which 121 women played a game that tested their level of fairness. One player started with 10 dollars (or a generic equivalent) and had to decide how many to offer a second player. If the second player accepted the offer, both women received the money. But if the second woman rejected the offer, neither received the money. The fairest decision would be to offer five. And it turns out that the women who made the fairest offers were those that had taken pills containing 0.5 mg of testosterone instead of a placebo.
This study was significant in showing that testosterone can affect human behavior, but not in the way that many people would predict. The authors suggest that the hormone promotes "status seeking" behavior. People with higher levels of testosterone are more likely to act in ways that elevate their social status. When incarcerated in prison this could have a negative impact by causing often dangerous behavior. But in other settings, like the bargaining game set up by these researchers, status seeking can promote behaviors that strengthen social interactions.
Ernst Fehr, an economist from the University of Zurich, set up an experiment in which 121 women played a game that tested their level of fairness. One player started with 10 dollars (or a generic equivalent) and had to decide how many to offer a second player. If the second player accepted the offer, both women received the money. But if the second woman rejected the offer, neither received the money. The fairest decision would be to offer five. And it turns out that the women who made the fairest offers were those that had taken pills containing 0.5 mg of testosterone instead of a placebo.
This study was significant in showing that testosterone can affect human behavior, but not in the way that many people would predict. The authors suggest that the hormone promotes "status seeking" behavior. People with higher levels of testosterone are more likely to act in ways that elevate their social status. When incarcerated in prison this could have a negative impact by causing often dangerous behavior. But in other settings, like the bargaining game set up by these researchers, status seeking can promote behaviors that strengthen social interactions.
Sunday, January 24, 2010
Memory and the nature of science
Ira Flatow, the host of Science Friday on NPR, recently had a great interview with Eric Kandel, a nobel laureate who discovered many of the basics of memory formation that we talked about last semester (remember NMDA receptors?). And he did much of this work using the Sea Slug (Aplysia) as a model organism.
There are also some great comments on the nature of science, and why Kandel loves being a scientist. It's worth a listen.
Thursday, January 21, 2010
The human nose might not be so bad
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