BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: experiment

Exercise causes changes in our gut microbes, but how is unclear

Sarah Campbell was just beginning her assistant professorship in exercise and science at Rutgers University when she became curious about whether exercise could influence microbes in the gut. As an athlete and also having studied cholesterol metabolism and exercise and diet during her PhD and postdoc, she decided that she wanted to pursue the study of exercise and its affect on gut microbes.

Sarah Campell combined forces with microbiologists and toxicologists from Rutgers and a pathologist from Oklahoma City to create an experiment to analyze fecal samples of male mice who are fed a normal or high-fat diet for 12 weeks. Some of the mice in each group were allowed to exercise while others weren’t. The results revealed that physical activity created a unique microbiome in the guts of mice, independent of the diets of the mice. The mice that exercised hosted Faecalibacterium, Clostridium, and Aloobaculum, unlike the sedentary mice. The high-fat diet also led to inflammation in the guts of the mice who didn’t exercise, and this was not seen in the mice that ate a fatty diet and exercised.

The following picture is of gut microbiota (microorganisms that live in the digestive tracts of humans)

The results of this experiment reinforced findings that came out a few years before that showed how exercise prevented weight gain and altered the gut microbes in mice that became obese while eating a high-fat diet. The results of the experiment also aligned nicely with a study that found that lean, sedentary people who exercised for six weeks developed increased levels of Clostridiales, Lachnospira, Roseburia, and Faecalobacterium in their guts. In addition, the study showed how these microbes returned back to baseline levels once the individuals stopped exercising. Obese individuals who began exercising also had changes to their gut microbes; however, these changes were different than those seen in the lean individuals.

Even though the reasons for the difference in changes between the obese and lean individuals aren’t fully understood, the results clearly show how exercise can change the gut microbiota of humans, regardless of diet or body composition.

Video Games: Can They Be Beneficial to a Child’s Learning and Development?

We’re told that video games are the downfall of today’s youth, but is it possible that there are video games that can help advance today’s youth? Well, researchers at the Children’s Hospital of Philadelphia wanted to test exactly that, and thus Project: EVO was born.

They used a fairly new branch of medicine known as “digital medicine.” According to DW Shaffer at the U.S. National Library of Medicine, “…”digital medicine” [is medicine] that is potentially more precise, more effective, more experimental, more widely distributed, and more egalitarian than current medical practice. Critical steps in the creation of digital medicine are careful analysis of the impact of new technologies and coordinated efforts to direct technological development towards creating a new paradigm of medical care.” The researchers set out to prove whether or not digital medicine could be used as an investigational treatment for children with autism spectrum disorder (ASD) and co-occurring attention/deficit-hyperactivity disorder (ADHD).

It is statistically proven that as many as 50 percent of children on the autism spectrum experience symptoms of ADHD, with about 30 percent of said children receiving a secondary diagnosis of ADHD. ADHD medications are far less effective, however, in children with both disorders than in those with only ADHD, which led researchers to conduct a study exploring alternative treatments.

The study included 19 children aged 9-13 who had each been diagnosed on the spectrum and experienced co-occurring ADHD symptoms. The care givers of each child, were asked to submit reports of his/her child’s ADHD symptoms, as well as his/her child’s ability to both plan and carry out specific tasks. Participants in the study were given either the Project: EVO treatment, which is delivered via an action video game experience, or an educational activity involving pattern recognition. The researchers were using the TOVA API score, an FDA-cleared objective, to measure each child’s attention.

“Our study showed that children engaged with the Project: EVO treatment for the recommended amount of time, and that parents and children reported high rates of satisfaction with the treatment,” Benjamin Yerys, Ph.D., a child psychologist at CHOP’s Center for Autism Research (CAR) and first and corresponding author on the study. “Based on the promising study results, we look forward to continuing to evaluate the potential for Project: EVO as a new treatment option for children with ASD and ADHD.”

The overall conclusion of the study, found that children engaged with the treatment for 95% of the recommended treatment sessions. The study also found that upon using Project: EVO, children showed improved attention both quantitatively (on the TOVA API score) and qualitatively, with a noticeable reduction of ADHD symptoms. Both parents and children deemed Project: EVO a worthwhile approach for treatment. Though the sample size of the study was small, the study showed that using Project: EVO was both feasible and acceptable; with potentially therapeutic effects.

C. Difficile Colitis: How To Prevent It

What is Clostridioides difficile Colitis, or C. difficile Colitis, and how can you get it? C. difficile Colitis is an infection of the Colon caused by an excess amount of the Clostridioides difficile bacterium in your intestines. Some symptoms of the infection include diarrhea, stomach pain, nausea, vomiting, fever, and blood in stool. C. difficile Colitis is spread by feces, it usually comes from touching a contaminated surface, then touching your mouth. As repulsive as it sounds, it’s actually a lot more common than you might think. Statistics reported by the U.S Centers for Disease Control and Prevention estimated that in 2015, more than 148 out of every 1,000 people contracted C. Difficile Colitis.

Clostridium Difficile Bacteria

 

Experiment:

Confused and concerned by these findings, Kashyap, a Gastroenterologist at the Mayo Clinic in Rochester, Minnesota, alongside her team, decided to conduct an experiment on mice to get to the bottom of this infection. It is known that a disturbance in the combination of gut microbes within a mouse, can, in many cases, cause a C. Difficile infection inside of them. That being said, the researchers, at random, extracted and transported fecal matter from people’s colons with either normal or disturbed microbiomes, and transplanted the gut microbes into the mice’s stomachs.

Results of the experiment, as they predicted, showed that the mice that received transplants from people with disturbed microbiomes were not able to fight off the C. Difficile infection as well as the mice who received transplants from people with normal microbiomes, could. The results showed that, anteceding the experiment, the mice who had received the transplant of disturbed gut microbiomes, experienced an increase in a few specific amino acids found in their gut, especially proline. Proline is a major food source of C. Difficile bacteria, which in turn, strengthens the bacteria, giving it an advantage over other microbes found in the gut, that do not consume proline. This proved that proline-deficient people have much less C. Difficile bacteria in their intestines, thus making them far less susceptible to contracting the infection.

All that being said, the best way to prevent C. Difficile Colitis, is to avoid any and all antibiotics containing proline and to consider taking probiotics with proline-eating bacteria in order to hopefully outrun and weaken C. Difficile bacteria within the intestines, helping to restore the balance of microbes. Please don’t hesitate to comment what you think!

Stem Cells…Key to Youth and Controversy

Have you ever wondered what it would be like to be young forever? With the help of stem cells, this is possible. Stem cells can regenerate skin tissues and can also be used to treat diseases. However, something as enticing as living forever has its controversies. There are two types of stem cells: embryonic (ES) and adult (iPS); the embryonic stem cells are the controversial type.

Embryonic Stem Cell

Embryonic Stem Cell

The only way to effectively use the embryonic stem cell is to kill a four to six day old embryo. Some people view this act as killing a baby, which sparks ethical arguments about whether or not to utilize embryonic stem cells. To avoid this controversy, scientists have been trying to use stem cells from iPS cells instead of ES cells, but they questioned the power of iPS cells compared to the ES ones.

Because genes may differ in the iPS cells from the its source, the ES cells, there is a possibility that these two cells do not have the same capability. One scientist notes that the source of iPS and ES cells differ, which can lead to differences in gene activity. The ES cells are derived from embryos, which are not completely identical to iPS adult cells.  However, recent scientific research shows that these two types of stem cells have more equal capabilities than scientists’ initially thought.

Scientists conducted an experiment to compare the genetic makeup between the ES and iPS cell. They manipulated the male type of each cell, which eventually allowed the ES cell to transform into the iPS cell. They concluded that the iPS cells genetically matched the ES cells’ parents, and that the iPS cells had more similarities with the ES cells than iPS cells had to each other.

Even though these two experimental cells genetically matched, the two cells were not identical. The experiment showed 49 genes that differed between the two stem cells. Because of this difference, scientists needed to see if this affected the functional capability of the cells. The researchers conducted another experiment that analyzed 2 of the 49 genes. One helps take in glucose, while the other helps break it down. Even though these two genes were more active in the ES cell than the iPS cell, they were equally efficient at their respective jobs. The scientists concluded that these two specific cells were functionally equivalent.

The many experiments that have been conducted on the topic of stem cells contribute to the increase in research for more ways to utilize stem cells, without the ethical controversy. Scientists are starting to employ different technological devices, such as 3-D printers to help develop and build stem cells. This ability to fabricate cells using technology overcomes previous obstacles of limited stem cell resources.

– Source Article

– More fun facts about stem cells here

Pull-Ups, Biology, and Our Sexist Society

Men and women are different, right? Guys have more testosterone, which leads to greater muscle mass, facial hair, deeper voice, and greater height. Women have more estrogen, which leads to the development of characteristics like wider hips, and breast development. Having less testosterone means it is harder to gain strength, but not impossible. Anyone can, with the proper training regimen  increase their strength, regardless of sex. This, however, goes against what New York Times writer Tara Parker-Pope writes in her article Why Women Can’t Do Pull-Ups. In it, she cites a study in which

 Three days a week for three months, the women focused on exercises that would strengthen the biceps and the latissimus dorsi — the large back muscle that is activated during the exercise. They lifted weights and used an incline to practice a modified pull-up, raising themselves up to a bar, over and over, in hopes of strengthening the muscles they would use to perform the real thing. They also focused on aerobic training to lower body fat.

According to the study, only four of the seventeen women were able to do one pull-up at the end of the study. I, along with several hundreds of people who have posted angry comments on this article, have several issues with this study, and with the title of the article.

First, they focused on exercises that would strengthen the biceps and latissimus dorsi. My question is, what about the deltoids and trapezius muscles, and the core muscles in the abdomen, and grip strength? All of these come into play to some extent in a pull-up.

Second, I know from personal experience that using an incline to work your way up to pull-ups, often called a supine row, does not work.  I tried this for months and still could not do a pull-up. What did work was jumping over the bar and lower myself slowly (this is called negatives), and using resistance bands to hold whatever weight I could not support while doing a full pull-up. Now, I can do pull-ups. And, when you really think about it, a supine row uses the same muscles but the movement is in no way similar, so it doesn’t make sense to see it as a “toned-down” pull-up for beginners.

Taken by Amber Karnes
http://www.flickr.com/photos/ambernussbaum/4472515271/
2010 CrossFit Games; Women did pull-ups with a 14 lb vest.

Third, how in shape were these women? This was not made clear in the article, and obviously, even after six months to a year, a morbidly obese woman may not be able to do a pull-up.  I think the issue with the study and the article comes down to two things: bad journalism and bad science.  When a 17 year old AP Biology student is able to poke a bunch of holes in your argument and find a bunch of flaws in your experimental procedure, the competence of the individuals involved comes into serious question.

So, readers, can YOU do a pull-up? Do you know any females that can do pull-ups? And, if you were to run the experiment, what would you do differently?

Comment!

Original Article:

http://well.blogs.nytimes.com/2012/10/25/why-women-cant-do-pull-ups/

 

Additional Information:

http://en.wikipedia.org/wiki/Supine_row

http://en.wikipedia.org/wiki/Pull-up_(exercise)#Muscles_used

 

Photo: http://www.flickr.com/photos/ambernussbaum/4472515271/

from single cell to multi-cellular

Have you ever wondered how single cellular organism evolved into multicellular organisms? In a recent New York Times article, some scientists decided to see if they could get single cellular organisms to somehow evolve into multicellular ones. The problem that they thought of was that in multicellular organisms there are many cells which die so that the entire organism can live on. Why single cell organisms would group together with other single cell organisms just to die for the new multicellular organism was puzzling.

They designed an experiment where they had yeast in flasks of broth where they were being shaken for a day and then left alone for the yeast to settle. Then a drop of the settled yeast was taken and transferred to a new flask where the yeast could continue to grow. This process was continued and would allow the yeast which had evolved to be the densest and to settle furthest down to be carried to the next flask. after a few weeks the scientists observed that the yeast was falling faster and was becoming cloudy at the bottom. When looked at under the microscope the scientists found that the yeast had evolved into snowflake shaped clumps of hundreds of yeast cells stuck together. These cells were not just unrelated clumps since when separated individually, cells would recreate these snowflake shaped clumps. This property of clusters of single celled organisms to make a multicellular like organism is not special to yeast. Another organism called choanoflagellates is a single celled organism that also exhibits these traits.

One of the more amazing parts about this was that to reproduce, branches of the snowflake clump would break off after growing too large. When looked at closer they found that a section of the cells near the branch commit suicide to separate the branch to allow it to grow into a new clump. Being able to create multicellular organisms that had cells willing to commit suicide for the rest of the organism in a matter of weeks was amazing and could mean that the history of single celled organisms evolving into multicellular ones might not be as complicated as previously thought. Even though this form of natural selection was done in flasks, the natural environment could have preferred multicellular organisms over single cellular organisms for a number of reasons.

Powered by WordPress & Theme by Anders Norén

Skip to toolbar