Medical Science Archives : Page 5 of 7 : Proslogion

More Consequences of Anti-Vaccination Misinformation

Vaccines are a powerful means by which certain diseases can be prevented. Many scientific studies demonstrate that they are both safe and effective, but unfortunately, there are those who have been convinced by misinformation produced by anti-vaccination groups. As a result, some infectious diseases are beginning to make a comeback in the United States. One of those diseases is measles.

One reason measles is making a comeback in the United States is that there are several other parts of the world where measles has a stronghold. Since world travel is common, it is easy for someone to import the disease back to the U.S. In most cases, this isn’t a problem, because most travelers come into contact with people who have been vaccinated. As a result, the virus has a difficult time spreading, and the traveler is usually the only one who ends up suffering from the infection. Every once in a while, however, a traveler will come into contact with a group that has a very low vaccination rate. When that happens, the disease spreads quickly.

For example, in April of 2013, an unvaccinated person returned home to North Carolina after spending three months in India. Along with souvenirs and stories, the traveler brought home the measles virus. Two other unvaccinated family members got the disease, and in the end, there were 23 confirmed cases of the measles. The vast majority of them (18) were among unvaccinated people. Two of the measles cases were in people of unknown vaccination status, and three were in people who were fully vaccinated.

This, of course, brings up a very important point. When people refuse vaccination, they often think that the only possible consequences will be to them and their family, but that’s just not true. No medicine, including vaccines, is 100% effective. Thus, there will be a small percentage of people who get the vaccine but are not fully protected against the disease. When unvaccinated people provide a breeding and transmission population for the disease, this increases the risk to all people, even those who are vaccinated.

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The Benefits of Musical Instrument Lessons Last A LONG Time!

violin_lesson — A recent study shows that musical instrument lessons can provide lasting benefits to hearing.
(click for credit)

My parents thought it was very important for all their children to have piano lessons. I think they believed it would give us boys (I have no sisters) some culture, so in first grade we all began learning how to play the piano. My brothers quit as soon as they were allowed, but I really enjoyed those lessons, so I continued. At one time, I honestly thought I would become a concert pianist, but unfortunately, my fingers are too stubby. I simply cannot play many pieces of music properly, because I cannot spread my fingers wide enough to span more than an octave. I still play for church (mostly on the synthesizer), and anyone who watches me play can see that I am truly having fun. I thank God that my parents thought those lessons were important, because they ended up providing me with a long-term hobby that has brought me a lot of happiness.

Long after my brothers quit playing the piano, they complained that those piano lessons (as well as the practicing that went along with them) were a big waste of time. They understood that I really got something out of the lessons, but they were convinced they received nothing. However, a recent study indicates that they may be wrong. They might enjoy better hearing now because my parents forced them to take piano lessons when they were young.

It turns out that when you listen to someone else talking, your brain does an incredible job of interpreting the quickly-changing sounds associated with speech. Especially when the person speaking makes a transition between a consonant and a vowel, there is a rapid change in the properties of the sound wave that hits your ears. To be able to recognize such transitions, your brain relies on its ability to link the sounds the ears are receiving to the time at which the sounds were received. This is called neural timing, and as you get older, your brain’s neural timing deteriorates. This is one reason older people have trouble following conversations. They may be hearing just fine, but if their neural timing is off, they can’t understand the words they are hearing.¹

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Some “Vegetative” Patients are Probably at Least Partially Aware

coma — An EEG image of a person in a vegetative state listening to a list of words that contains the word to which he is attending and a bunch of distractor words. (click for credit)

The Royal College of Physicians defines a vegetative state as:¹

a clinical condition of unawareness of self and environment, in which the patient breathes spontaneously, has a stable circulation, and shows cycles of eye closure and opening that may simulate sleep and waking

When I read this definition, a question immediately arises: How do you know whether or not a person is aware of himself or his environment? You might ask him a serious of questions, but if he doesn’t have the ability to move his mouth or other parts of his body, how can he make you aware of his responses?

A few years ago, Dr Steven Laureys made headlines with his pronouncement that a man in a coma was able to communicate with people when given the aid of a keyboard and someone to support his hand as he typed. Based on Dr. Laureys’s work, it seemed that the man was describing exactly what you might think is going on in the mind of a person who is aware of himself and his surroundings but cannot communicate with the outside world. However, as skeptics started pointing out the flaws in Dr. Laureys’s method, further tests were done, and it turns out that the person supporting the patient’s hand was actually directing the patient’s hand. In other words, the patient wasn’t communicating; the helper was.

So what can we say scientifically about such patients? If they cannot do anything to communicate with the world, how do we know whether or not they are aware of it? A collaboration of scientists from Cambridge University, the University of California at Los Angeles, and the University of Western Ontario have gotten us a step closer to answering that question. They have published a study in the journal NeuroImage: Clinical that might help us produce a method by which an aware patient can communicate, even if he is not able to do so by traditional means.

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Astounding: Your Baby Can Heal You!

fetus_cells — This Facebook Meme is actually correct!

I avoided Facebook for a long time, but a few years ago, I finally gave in. Not long after I started connecting with long lost friends and finding out what everyone was eating, I learned the joys of Facebook memes. Every day now, I see lots of pictures with snarky sayings on them coming across my news feed. Some of them are funny, and some try to make a point. Many times, the ones that try to make a point are just dead wrong. They include either outright falsehoods or an incredibly mischaracterized fact. Thus, whenever I see a “science meme” or a “political meme,” I generally ignore it.

However, when the meme at the top of this article came across my newsfeed, I had to investigate it. If you have been reading this blog for a while, you might remember that almost two years ago, a talented writer named Amanda Read posted a story about how a baby’s cells reside in his or her mother long after the baby is born, and they may aid the mother in healing certain kinds of tissues. I was incredibly skeptical of the story, but when I did some investigation, I found out that it was true. Later on, I learned about a study that showed how a baby leaves DNA behind in his mother’s brain, and those “fetal remnants” might even fight against neurological disorders!

Since we are still barely scratching the surface in our understanding of the the amazing design behind pregnancy, I decided to pay attention to this Facebook meme. Of course, I knew that the statement on the left is true. All sorts of things pass through the placenta from the mother to the child, and that includes blood proteins which fight disease and shape the development of the baby’s B-cells.¹ Those B-cells will affect the child’s ability to fight disease for the rest of his or her life.

I was, however, very skeptical of the statement on the right. Surprisingly, there is strong scientific evidence to back it up!

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Poop Transplants Treat Clostridium difficile Infections!

cdifficle — *Clostridium difficile* from a stool sample, magnified 3,006x (public domain image fron the CDC)

Clostridium difficile is a bacterium that produces toxins which can kill intestinal cells and cause severe inflammation of the intestinal walls. Mild infections from this bacterium can cause diarrhea, while severe infections can cause death. Over time, C. difficile infections have gotten worse. As one medical resource states:¹

C. difficile infection has transformed from a nuisance into a potentially life-threatening illness with an attributable mortality rate of up to 16.7%.

The typical treatment for severe cases of C. difficile infection is a round of strong antibiotics, but that doesn’t always work. A significant number of patients end up experiencing one or more recurring infections within 60 days.² As a result, medical researchers are trying to come up with new ways to treat this infection.

In a recent study published in the New England Journal of Medicine, researchers tested an…interesting…approach. They took 43 patients who had a C. difficile infection and split them into three groups. The first received the standard antibiotic treatment (in this case, 500 milligrams of vancomycin four times per day for 14 days). The second received the standard antibiotic treatment plus a bowl lavage 4 or 5 days into the treatment. In case you aren’t familiar with the term, a bowel lavage involves flushing out the intestines. It is usually done to prepare the intestine for medical imaging. The third group was given a shortened round of antibiotics (500 milligrams of vancomycin four times per day for 4 or 5 days), a bowel lavage, and then a poop transplant.

Yes, you read that right. After the bowel lavage, the patients were given a mixture of water, salt, and the feces from a healthy donor. Now don’t worry. They didn’t have to eat or even smell the stuff. It was sent into their intestine through a sterile tube that went up the nose, down the esophagus, through the stomach, and into the start of the small intestine. While the process sounds incredibly gross, the results were amazing!

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Male DNA in Female Brains? Yes!

brain_male_female — Male DNA was found in 63% of the women studied.
(Public domain image)

A gene called DYS14 is found only on the Y chromosome in human beings. Of course, only males have a Y chromosome, so it is reasonable to assume that the only place you will ever find this gene is in men, right? Wrong! William F. N. Chan and his colleagues examined the brains of 59 deceased women, and they found the gene residing in 37 of the brains studied! In other words, 63% of the deceased women studied had male DNA in their brains. Interestingly enough, in most of those brains, the DNA was found in several different places!¹

How in the world did male DNA get into these women’s brains? The researchers aren’t sure, because they don’t have detailed medical histories for most of the women. However, the most likely explanation is that the DNA comes from the male children that these women carried. I have written about this phenomenon, called fetomaternal microchimerism, before. As I mentioned in that article, when I first heard about a baby leaving cellular remains inside his or her mother, I thought it couldn’t possibly be true. However, I was wrong. There is solid evidence to suggest that not only do babies leave a lasting, cellular imprint on their mothers, mothers do the same for their babies.

However, the possibility that children leave some of their DNA behind in their mother’s brain is very surprising. After all, the cells that make up the brain are incredibly sensitive. In fact, the contents of your own blood are toxic to your brain cells. As a result, you have an elaborately designed blood-brain barrier that shields your brain cells from your blood. This barrier is so vigilant that it allows only certain substances (such as the glucose and electrolytes that the brain cells need) to pass through it. As a result, your brain cells are protected from the majority of substances found in your bloodstream.²

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Is A Knee Replacement on That Playlist?

Last month, I wrote an article about an experiment involving spiders and an iPod touch. The results of the experiment were interesting, but I also thought it was really cool that an iPod was integral to the experiment’s design. Well, I just learned about something that I think is is even cooler. It turns out that an iPod touch is being used to assist in knee-replacement surgeries!

The system is called “Dash,” and it is made by a company called Brainlab. It consists of several accessories, such as probes, that attach to an iPod touch. Once everything is sterilized, the surgeon can use the probes to make measurements on the patient while the surgery is in progress. The iPod can then do some calculations on those measurements and show an image that will help the doctor install the artificial knee as accurately as possible. It can also use its WiFi capabilities to send those results to any other device, such as an iPad, if the surgeon wants a larger, more detailed image.

Why would a surgeon use a device like this? Well, in order for the replacement knee to function well, it must be aligned properly. In conventional knee replacement surgeries, the surgeon inserts a metal rod into the femur (the bone above the knee) to help with this alignment. Unfortunately, that process can increase the risk of certain side effects, such as fat embolisms. When using this iPod-based device, there is no need for an alignment rod. In addition, a surgeon who has been using it for more than a year says that the device provides better alignment than the conventional method. This leads to a larger range of motion for the artificial joint. Also, patients experience less pain and swelling after surgery.

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Remember That Nuclear Disaster in Japan?

On March 11 of 2011, the most powerful earthquake known to have hit Japan struck near the east coast of Honshu. The earthquake generated a tsunami that reached a height of more than 130 feet. Just last month, the Japanese National Police agency reported that there were at least 15,870 people who died, an additional 6,114 who were injured, and 2,814 who are still missing as a result.¹ Obviously, it was a disaster of truly stunning proportions.

One of the many things that happened as a consequence of the disaster is that some of the reactors at the Fukushima Daiichi Nuclear Power Plant went into meltdown, and radioactive substances were leaked into the ocean and released into the air. People in a 12-mile radius around the power plant were evacuated so that they would not be exposed to too much radiation. As a result of the meltdown, there is increasing political pressure for Japan to end its reliance on nuclear power. According to the Christian Science Monitor, Prime Minister Yoshihiko’s party has recommended that Japan phase out all nuclear power by the year 2030.

Back when the nuclear disaster was in the news, I commented on it (here and here). Since then, I have been following the scientific literature to see what those who have been monitoring the situation are saying regarding its long-term effects. Recently, a study and some commentary on the study were published in the journal Energy & Environmental Science, and they are surprising, to say the least.

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Motherhood Has a Lasting, Cellular Impact!

In pregnancy, the placenta is a barrier between the baby and the mother (Gray's Anatomy Image)

A very interesting writer named Amanda Read is a Facebook friend of mine. She has an amazingly diverse reading list, and she often posts things that she has read and found interesting. A while back, she posted a story about how a baby’s cells reside in his or her mother long after the baby is born, and that they may aid the mother in healing certain kinds of tissues. When I read the story she posted, I immediately expressed my skepticism. After all, we have an amazing immune system that fights any cells that are identified as foreign. Even though the baby develops in the mother’s body, there is a placenta that forms a barrier between the mother and the baby. It was obvious to me that a baby’s cells could not pass across the placenta, because the mother’s immune system would immediately attack them as foreign cells.

Well…it turns out that I was dead wrong. When I actually looked into the story, I found that while the story was a bit biased, the fact is that a baby’s cells do, indeed, cross the placenta, and they do, indeed, stay with the mother for a long, long time. In addition, the mother’s cells cross the placenta and stay with the baby for a long, long time. This phenomenon is called fetomaternal microchimerism, and believe it or not, scientists have known about for quite some time.

The first paper that discussed this phenomenon was written by Herzenberg and his colleagues in 1979. Published in The Proceedings of the National Academy of Sciences USA, the paper details how they found cells with Y chromosomes in mothers after pregnancy, but only if the baby was a male.¹ Since a woman has no Y chromosomes, it was clear that the cells they found didn’t belong to the woman. The authors didn’t have the ability to use genetic testing to confirm that the cells belonged to the baby, but they showed that these Y-chromosome-containing cells appeared only when the mother had a baby boy. Thus, it was clear that the cells must be coming from the baby.

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Stem Cells: Induced Ones Make The Same Proteins as Embryonic Ones

When your mother’s egg cell was fertilized by your father’s sperm cell, the result was a single cell, called a zygote. That cell had all the information necessary to develop into the person you are today. In other words, it could produce everything necessary to build you. So that single cell had the capability of developing into any human cell. We call such cells totipotent cells. Of course, in order to make all those cells, the zygote had to start reproducing, resulting in an embryo.

As this cell (and its progeny) reproduced, the number of cells in the embryo grew. When that reproduction had produced about 12 cells, you were in the morula stage of your development, and on a microscopic level, you resembled a mulberry. As your cells continued to reproduce, they formed a hollow sphere called a blastocyst. At one end of the hollow sphere, there was a bunch of cells called the inner cell mass, which is represented by the blue cells in the illustration above. That inner cell mass developed into all the organs and tissues that make up your body.¹

Interestingly enough, however, the cells in that inner cell mass were no longer totipotent. They could not, for example, form the kind of cells that make up the outer layer of the blastocyst, which are shown in yellow in the illustration above. However, they could end up becoming any of the cells in any of the organs or tissues of your body. As a result, they are called pluripotent cells. As they continued to reproduce, they started “choosing” what kind of cell they would become. Some of those pluripotent cells, for example, became skin cells. Once they did that, we say that the cells had differentiated. This means they lost their pluripotency, and would no longer be able to become some other type of cell. As a result, they would end up doing the same job for the rest of their lives.

Pluripotent cells are often called stem cells, and they have a lot of potential in medicine. After all, if someone suffers from severe organ damage, I could theoretically get his or her body to rebuild that damaged organ if I supplied it with enough stem cells. The stem cells could then differentiate into whatever cells are needed to replace those that died when the organ was damaged. While this sounds wonderful, there is a problem. The most ready source of pluripotent cells come from the blastocyst stage of an embryo’s development. If I remove those pluripotent cells from the blastocyst, I have embryonic stem cells, but unfortunately, the embryo dies.

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