BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Ethics

Dead Pig Brains Were Brought Back to Life…Kind Of

A recent article published by Christof Koch raises the question of if death is really as final as it seems.

Koch highlights a study undergone by a sizable team of physicians and scientists at Yale School of Medicine, led by Nenad Sestan. This group used hundreds of slaughtered pigs from the Department of Agriculture to carry out a rather extraordinary experiment. 

The experiment began with the removal of the pig brains from the pigs’ skulls. The veins and carotid arteries were then connected to a perfusion device that created the effect of a heart beating. This perfusion device circulated a synthetic concoction, or a type of artificial blood, containing drugs and oxygen with a specific molecular constitution that would protect the cells from damage. Sestan’s team studied these pig brains’ capability to survive four hours after the pigs had been electrically stunned, bled out, and decapitated. His team also compared these pig brains with others that were not connected to a perfusion device. 

A closer look on a pig brain (not from the actual experiment)

The tissue integrity of the pig brains that were connected to the perfusion device was preserved and there was also a decrease of the swelling that causes cells to die. In addition, synapses, neurons, and output wires (axons) looked normal. The glial cells, which support neurons, had some function, and the brain consumed glucose and oxygen. This means that there was some metabolic functioning. The researchers seemed very satisfied with their findings and titled their paper “Restoration of Brain Circulation and Cellular Functions Hours Post-mortem.”

However, brain waves, like those from EEG recordings, were not found in the pigs’ brains that were connected to the perfusion device. There were electrodes put on the surface of the brains but no great global electrical activity was recorded. This, although, was intended. In theory, bringing a pig that had just gone through such trauma back to life could’ve led to a number of horrible side effects. Some include massive epileptic seizures, delirium, deep-seated pain, distress, and psychosis. It was because of this fact that Sestan’s team ensured the artificial blood contained drugs that suppress neuronal function. 

According to Koch, this experiment causes a new question to surface: “What would happen if the team were to remove the neural-activity blockers from the solution suffusing the brain?”. In reality, it is probable that nothing would happen. Even though some neurons responded to the stimulation doesn’t mean that millions would be able to. However, it can’t be completely disregarded that maybe with some external support the seemingly dead brains can be brought back to life.

Keeping this in mind, one may wonder if this can be applied to human brains. The pig brain is the most popular laboratory animal as it has a fairly large brain that has a folded cortex similar to that of a human brain. Because of this, in theory, the human brain could undergo the same experiment. Even so, the question of if this would really be ethical or not is a factor that should definitely be taken into consideration.

If possible, do we have the right to bring dead brains back to life?

A CRISPR Controversy

The Issue:

A recent article published by Grace Tsoi highlights the ongoing controversy regarding CRISPR, a new technology capable of editing DNA sequences, and thus genomes. Among those experimenting with CRISPR is Chinese researcher He Jiankui, notoriously nicknamed “China’s Dr. Frankenstein.” Many are critical of He Jiankui, as they deem his work with CRISPR — such as producing the world’s first gene-edited babies — inhumane and unethical. He Jiankui, however, argues that CRISPR has the potential to help “…millions of families with inherited diseases or exposure to infectious disease.”

Pictured above is He Jiankui, researcher and associate professor of the Southern University of Science and Technology’s Biology Department.

The Study:

In proving CRISPR’s potential, He Jiankui referenced an experiment in which he was able to produce two healthy twin girls by manipulating their genes, specifically making them resistant to HIV. He Jiankui had ultimate success with CRISPR technology, as the twins produced were not HIV positive, unlike their biological father. To learn more about the threat of HIV during contraception, click here. While He Jiankui expressed pride to his audience, stating, “For this specific case, I feel proud actually. I feel proudest because Mark [father of the twins] thought he had lost hope for life,” some audience members did not feel the excitement. Rather, his animated claims were met with intense criticism.

The Risks and Suspicions:

Given CRISPR’s potential, why are people so critical? Is CRISPR’s label “gene scissors” accurate or oversimplified? Regardless of these answers, it is undeniable that utilizing CRISPR for human embryos is a much more complex process. As Kenneth Lee, a biomedical sciences professor at the Chinese University of Hong Kong, explains it, using CRISPR in human embryos is “highly risky,” and could potentially mutate other genes in the process. As a result, the embryo might not survive, or could acquire deformities and/or other genetic disorders. Adding another element to the audience’s suspicion of He Jiankui’s experiment was the secrecy surrounding it, as he failed to answer why he initially hid it from Chinese officials. Failing to consider the opinions of these aforementioned officials has left many questioning the genuine ethics of He Jiankui’s experiment. In defending his work, He Jiankui emphasized that every individual involved consented to his experiment and were well-educated on the study itself. However, the consent form uploaded to his website, explicitly states that He Jiankui would not be held responsible for any unintended gene mutation. Moreover, the University where he conducted his experiment appeared unaware of his lab work, thus rendering an investigation of He Jiankui’s activities. Although China is a more “relaxed” country regarding its gene editing rules (gene editing is banned in the U.S., as well as many other countries), He Jiankui has faced condemnation from many Chinese scientists. Despite this, he plans to expand his studies, focusing next on another gene-edited pregnancy — yet another controversial experiment that will prove to either have potential or deep ramifications. 

Crispr-Cas9 is the gateway to a new frontier in genetic engineering. Here’s The good and the bad.

For a number of years now, molecular biologists have been diving increasingly further into the field of genome editing. The latest development into the field is the emergence of CRISPR-Cas9. CRISPR-Cas9 has risen to prominence over other potential methods of genome editing due to its relatively simple construction and low cost. CRISPR-Cas9’s original primary and intended purpose was to help fix mutations within DNA, and with this it could theoretically help eradicate entire diseases. This application of CRISPR is wholly positive, however with the increasing prevalence of the technique other potential uses have been discovered, and some of these potential uses raise profound ethical questions.

One of the main concerns of people skeptical about CRISPR is their assertion that once the door to the wholesale genetic editing of offspring is open, there is no going back. This, on its own, is a reasonable concern. The ability to choose a child’s sex, eye color, hair color and skin complexion is very likely to be made available to by CRISPR in the coming years. CRISPR does not yet have the capability to influence more abstract elements of the genome, such as intelligence and athletic ability, but this may not be far off. There are legitimate concerns that this is a slippery slope towards a dystopian society similar to the one seen in the movie Gattaca, where society is stratified into two distinct classes: those who are genetically engineered and those who are not.

Another concern raised by some scientists is the overall safety of genetic editing. A potentially very hazardous negative result of CRISPR is the possibility of an “off target mutation.” An off target mutation is the result of CRISPR mutating something other than the intended part of the genome and it could have disastrous consequences. Now, many scientists believe that with further advancements in the field the likelihood of something like an off target mutation occurring could be reduced to almost zero. However, it is important to examine the risks of any new process, and the prospect of something like an off target mutation occurring is certainly noteworthy.

For more information click here.

Crispr-Cas9: Coming to a Theater Near You

This sequel to GATTACA is to be released shortly, and this time, they’re transcending the movie screen and bringing the experience to reality!

Crispr-Cas9 is a fairly recent DNA-editing technique that has been developed, and allows for extremely easy and precise gene editing, a development said to be at least on par with PCR for bio engineering. In many ways, this is great. Now biologists won’t have to spend the time nor undergo the difficulty of creating variant DNA through old methods, meaning that all these cool genetic breakthroughs should be happening at an unprecedented pace! The problem is, it may be going too fast for humans to wrap their head around.

Similar to the ethical questions raised by the film GATTACA, countries and scientists are debating what regulations should be put on this new and powerful tool. With Crispr-Cas9, the possibility to genetically modify humans becomes a very real option to consider. Scientists could remove DNA sequences which lead to defects and diseases such as albinism and Huntington’s Disease. Or anything else, really.

(The miracle protein)

The main point of Crispr-Cas9 is not necessarily the ability it gives to scientists to easily modify DNA, but the increased rate at which we can understand what specific sequences of DNA do by altering them. Not only are we more able to modify DNA, we are now able to figure it out at breakneck speed.

 

Where it gets complex is, as always, how humans deal with it. Some people, such as Mark Leach, whose daughter has down-syndrome, believes that children with disabilities not only are still able to live rich lives, but also teach others to be more compassionate. Although debating if I would choose to let my child have down-syndrome or not for that reason seems like an absurd consideration, and most likely a coping mechanism, the point still stands that some people are uneasy with fixing genetic-related problems because “they wouldn’t be the same person.” (That’s the point!)

People are really afraid of change, aren’t they?

 

However, for those on the more lethal/completely disabling part of the genetic spectrum, the answer is more than clear.  Charles Sabine, the brother of the renown British lawyer John Sabine, who both have Huntington’s Disease at varying stages, says “If there was a room somewhere where someone said, ‘Look, you can go in there and have your DNA changed,’ I would be there breaking the door down.” Similarly, Matt Wilsey, a parent of a child with a terminal genetic illness, is awestruck at the ridiculousness of the situation: “As a parent with an incredibly sick child, what are we supposed to do — sit by on the sidelines while my child dies?” The oddity of the situation is, we have the capability to start figuring out how to solve these genetic issues with a very effective and efficient technique, it’s just that humans are riding the brakes, trying to slow down the almost inexorable progress of the freight train that is Crispr-Cas9. The irony is that many are afraid with tampering with the “sanctity” of human embryos. I would agree, except that humans defile it all the time. Birth defects, genetic diseases, miscarriages, etc. Of course, this is not intentional, but the parents have the largest hand in these outcomes, as they provide all the material,genetic and otherwise, to create the embryo, fetus, and eventually child. We are already making horrible mistakes with human embryo’s that cripple or kill the resulting child through the natural birth process. Personally, I would go off of this to say we should at least learn from this, so we could eventually progress far enough to prevent these things from ever happening, but I only ask all of the readers to keep this in mind: Nature (very badly) screws up too.

File:Crispr.png

(The process Cas9 facilitates)

I’m not saying that we should be careless with this new and potentially dangerous or aberrant-spawning technology, but I think it’s time that humans come to terms with the fact that their world, and their lives, are entering a new era of existence. For millennia, structured humans have lived in a world where the outside world is the only thing we can manipulate, but now the very structure and formation of ourselves as well. I understand that such a change from a thousands-year-running viewpoint can be hard to make. We’ve never had to think about these things before as a species, because it wasn’t understood and out of our reach. It is daunting. It is terrifying. Only because it is unknown. But how are we to learn, to benefit, from this great potential, if we are too afraid to explore it? I understand that like any form of potential, it can go either way, but this is a great new time of possibilities that simply won’t go away, but reemerge constantly.

I think it’s time we gathered the courage to face it.

Crispr 9, A Dangerous New Field

CRISPR-Cas9_mode_of_action

Crispr 9 Editing

With the new developments in gene altering, scientists have begun to use technology to alter the gene sequence of embryos. According to an article by Tia Ghost, Chinese scientists have modified the genes of human embryos with mixed results. The idea behind the research was that they would cut out a faulty gene in the DNA sequence and replace it with a correct one, therefore improving the embryo. This is done through a stretch of RNA called CRISPR targets places on the genome that are then cut by Cas9, an enzyme that cuts out specific strands of DNA leaving a spot to be filled within the genome. Scientists then provide a new strand of DNA as replacement. This method is effective in all different kinds of animals as well as humans.

However, the technology is not yet accurate enough to become common practice. According to a leading scientist in the field “the CRISPR technology is simply too risky to use in embryos” at this point. The issue arises in the fact that the RNA sometimes goes to a different site then the one desired, slicing out a necessary part of the genome and replacing it with useless information. This could lead to harmful mutations in the embryo, the opposite of what the scientists want. Even if the technology was at a higher level, editing embryos is still a large ethical dilemma. Some scientists feel that they should not alter life, but simply let it play out the same way it has for billions of years. Other’s argue that each child deserves the best possible chance they can get. Both have strong arguments, and only time will tell which side will win out.

 

 

 

Original Article:

http://www.livescience.com/50596-what-are-genome-editing-risks.html

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