human body – BioQuakes

Tag: human body

Parkinson’s, a disease of the central nervous system, affects approximately one million people in the United States. While the disease known for impairing motor skills, it can also have digestive symptoms such as constipation years before diagnosis. Because of this phenomenon, scientists have begun to investigate the role of gut microbiome composition in this awful disease. One such study conducted by a team at Caltech used transgenic mice to get to the answer. All of the mice overexpressed the protein human a-synuclein, which can form the insoluble fibrils that lead to Parkinson’s. However, the researchers raised some of the mice germ-free, or gave them antibiotics, so no intestinal microbes formed. In these mice, Parkinson’s-like symptoms and brain pathology decreased. In addition, the researchers found that the mice that did have gut microbiota had brain inflammation that the germ-free mice didn’t. Only when the researchers fed the germ-free mice short-chain fatty acids (to stimulate gut microbiota) did they show signs of inflammation and other Parkinson’s symptoms. This suggests that gut microbiota that produce short-chain fatty acids could be what triggers this disease.

The researchers then tried to investigate more about which gut bacteria could cause Parkinson’s. Since different communities of gut bacteria live in people with Parkinson’s disease than in healthy people, they wanted to find out if these different communities are merely a byproduct or a cause of the disease. To do so, they transplanted human gut-derived microbes from Parkinson’s patients into some mice, and microbes from healthy people into others. The transgenic mice with microbiota from the Parkinson’s patients ended up with typical Parkinson’s symptoms like motor dysfunction. However, wild-type mice (mice that didn’t overexpress human a-synuclein) weren’t affected. This finding shows that people who are genetically predisposed to Parkinson’s can be afflicted with symptoms if introduced to microbes that are associated with the disease.

This is such groundbreaking work because it establishes a causality between the gut microbiome and Parkinson’s. It also raises questions about the negative affects of short-chain fatty acids on the mice in this study, since they’ve been known to be beneficial in humans. The researchers wish to continue their work by investigating the types of microbes in people with Parkinson’s to get to the fundamental cause of the disease and possible cures.

Do you think that short-chain fatty acids are actually harming humans in unseen ways? Is investigating human gut microbiomes is the right path to find the cure to Parkinson’s? Let me know in the comments!

Human Intestinal Cells Cultured with Gut Bacteria

Credit: Scitechnol Publisher, URL: https://flic.kr/p/fzFoNE

Original Article: http://www.the-scientist.com/?articles.view/articleNo/47640/title/Gut-Microbes-Linked-to-Neurodegenerative-Disease/

Attention all penicillin-allergy victims, you might not actually be penicillin-allergic!

By izerstellar

On November 9, 2015

In Student Post

Photo of antibiotics (licensing information here)

I am someone who is allergic to penicillin, amoxicillin, and a bunch of other “cillins”. So, when being prescribed with antibiotics, penicillin is always ruled out as an option for treatment. However, new findings at the American College of Allergy, Asthma, and Immunology (ACAAI) show that people, like me, who were told after a single allergic reaction to penicillin that they were penicillin-allergic, may not be penicillin-allergic after all!

At the Annual Scientific Meeting at the ACAAI, a study was presented where 15 students who were supposedly penicillin-allergic tested negative for a penicillin allergy and were in fact treated with intravenous penicillin medication multiple times. Dr. David Khan and Dr. Roland Solensky, both allergists, are both majorly involved in this research. They each stated that people who are found allergic to a medication such as penicillin are then prescribed with more expensive and dangerous medications to take the place of the medication they are allergic to. In fact, almost 10% of Americans are labeled penicillin-allergic and have no choice but to use more complex medications, when they might not even be allergic to a simpler medication, such as penicillin, in the first place!

To attempt to resolve this problem, Dr. Solensky is going to present “Drug allergy: options beyond avoidance” at the next Annual Meeting at the ACAAI. This presentation is designed to discuss different treatment options for patients suffering from allergies to certain medications, as well as patients who were told they are allergic to medications that they are in fact not allergic to. Dr. Khan encourages everyone who is penicillin-allergic to get tested and see if penicillin is a medication they should actually avoid or if the allergic reaction they once had to penicillin was a fluke. This study can help people avoid medications that are overly expensive or that can be dangerous, and just in general help people find more appropriate medications. I sure know that I’m interested to see if I’m actually penicillin-allergic, or if that allergic reaction I had in second grade was a one time thing!

Main article:

http://www.biologynews.net/archives/2015/11/05/consider_penicillin_even_if_you_have_had_a_prior_reaction.html

Does long-term endurance training impact muscle epigenetics?

By mitokahndria

On March 8, 2015

In Student Post

Epigenetics translates to “above” or “on top of” genetics. To be more specific, Epigenetics is the study of how modification of gene expression can cause changes in many organisms.

A new study from Karolinska Institutet in Sweden explores the theory that long-term endurance training alters the epigenetic pattern in the human skeletal muscle. The team that conducted the research also explored strong links between these altered epigenetic patterns and the activity in genes controlling improved metabolism and inflammation.

The study was conducted using 23 young and healthy men and women. The men and woman would perform one-legged cycling – where the untrained leg would be the control of the experiment. Four times a week and over the course of three months, the volunteers would participate in a 45 minute training session. Though skeletal muscle biopsies, supervisors would measure their markers for skeletal muscle metabolism, methylation status of 480,000 sites in the genome, and activity of over 20,000 genes.

At the end of the study, the researchers concluded that there was a strong relationship between epigenetic methylation and the change in activity of 4000 genes in total. Epigenetic methylation is defined as the “addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. ” Moreover, it was determined that methylation levels increased when involved in skeletal muscle adaptation and the metabolism of carbohydrates. However, methylation levels decreased in regions associated to inflammation.

Furthermore, Carl Johan Sundberg found that “endurance training in a coordinated fashion affects thousands of DNA methylation sites and genes associated to improvement in muscle function and health.” He believes that this determination could be vital to understanding the treatment of diabetes and cardiovascular disease as well as how to properly maintain good muscle function throughout life.

This article relates very much to our work in class as we learn the Molecular Genetics Unit. It connects because we are learning what happens when mutations occur in one’s genome and the impacts those mutations have on someone. For example, cancer is one of the most researched and explored topics in regard to how modification of gene expression alters organisms. Oncogenes and Tumor suppressor genes have vital impacts on cellular division, changes to cellular function, and the growth of tumors.

Out Like a Light: Sleep Switch in Brain Identified

By karbonkim

On February 27, 2014

In Student Post

Researchers from Oxford University’s Center of Neural Circuits and Behavior have identified the switch in the brain, which causes sleep, from a study of fruit flies. This switch regulates sleep promoting neurons in the brain. When one is tired and in need of sleep, these neurons will activate. Once you are fully rested, neuron activity will die down. Though this new insight was gained through studying fruit flies, or Drosophila, the researchers believe this information is also relevant to humans. In the human brain, there are similar neurons that are active during sleep and are the targets of general anesthetics that cause sleep. These facts support the idea that humans have a sleep mechanism like that found in fruit flies, according to Dr. Jeffrey Donlea, one of the lead authors of the study. The findings of this study were published in the journal, Neuron.The discovery of this sleep switch is important for a number of reasons like finding new treatments for sleep disorders, but it is just a small piece of the enigma that is sleep. The internal signal, which this sleep switch responds to, is still unknown, as is the activity of these sleep-promoting cells while we are awake. We do not even know why humans and all other animals need sleep.

In spite of these mysterious, scientists do know how the body regulates sleep. Humans and animals have a body clock, which makes us accustomed to the 24 hour cycle of day and night, and a sleep switch, which logs the hours you are awake and causes you to sleep when you need rest. When this mechanism is off or not being used, sleep deficiency increases. The combination of these two is the most likely cause of us sleeping at night.

The significance of this switch in the process of sleep and its relationship to bodily function was found when studying the fruit flies. If they did not sleep, mutant flies cannot regain these lost sleep hours. Sleep-deprived flies are also more likely to nod off and be cognitively impaired. Like sleep-deprived humans, these flies were subject to severe learning and memory deficiencies. In the mutant flies, the researchers proved the insomnia of the flies was due to a broken part of the electrical activity switch, which caused the sleep-inducing neurons to always be off.

Why do you think sleep is important? How is this discovery significant and how do you think this information will be used in the future? Will the mystery of sleep be solved soon?

Photograph by Pedro Ribeiro Simões

Osmosis Jones: Fact vs. Fiction

By henroids

On March 10, 2013

In Student Post

The Cells of the Immune System
Photo from: http://commons.wikimedia.org/wiki/File:Innate_Immune_cells.jpg

Osmosis Jones is the story of a white blood cell police officer, Ozzy, who teams up with a cold pill, Drix, to save Frank from a deadly virus. Of course being a children’s movie Osmosis Jones isn’t a completely accurate depiction of the human immune system, or body in general, but just how accurate is it?

In the movie the major conflict arises when Frank, the human, eats an unsanitary egg. On this egg lives the virus, Thrax, who is a deadly pathogen. So far the movie checks out. In the human immune system the first line of defense are barriers between the inside of the body and the outside world. Some of these barriers include the skin, mucus membranes, tears, saliva, sweat and stomach acid. In the movie the virus does penetrate one of these barriers, in this case the mouth, to enter the body. This is accurate to how a virus may enter the human body.

After this the movie becomes less and less accurate to how the human immune system functions. Although there is detection of a pathogen the only response Frank’s immune system has in the movie is through the use of the police force, the white blood cells. This is completely inaccurate to how the human body fights off a pathogen. When the body detects a pathogen (virus or bacteria) mast cells release histamines to dilate the blood vessels (this is never shown in the movie, especially because the blood vessels are shown as highways, but thats another matter altogether). The next step in the immune response is macrophages come and engulf infected and dead cells and they release cytokines that attract other immune cells to the area. Neutrophils and natural killer cells then kill the infected cells. The closest thing to this second line of defense is the police force and their communication. They have radios and ways to communicate to call for backup, although it is extremely inaccurate to the way the immune system really functions.

The third line of defense that the Human body uses is specific defense. This includes B and T cells and the steps taken to target the pathogen specifically and the infected cells. Through the processes of Cell-mediated response and Antibody-mediated response the immune system targets the infection and destroys it. Both of these processes are not depicted in the movie in any form. This along with the ending (don’t worry I won’t spoil it) are both inaccurate to anything that could happen in the human body.

So Osmosis Jones isn’t the most scientifically accurate movie of all time, but that doesn’t stop it from making a great movie. The inaccuracies in the film can be excused by the fact that it is a children’s movie and not a new theory about the immune system. I mean how many kids would want to sit though a movie that was 100% accurate? You would lose all of the car chases, the drama, the suspense, the mucus filled dams, and the explosions. Overall I really enjoy Osmosis Jones, although I don’t recommend using it to study for your next science test.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: human body

Gut Microbes and Parkinson’s Disease: A Fascinating New Study

Attention all penicillin-allergy victims, you might not actually be penicillin-allergic!

Does long-term endurance training impact muscle epigenetics?

Out Like a Light: Sleep Switch in Brain Identified

Osmosis Jones: Fact vs. Fiction

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