Completed Project

Hello all! I have now finished my AS exams, as well as the GMO paper with my group. Those combined would be why I haven’t thought to post anything in a few weeks.

Anyway, the paper sits at over 3700 words and details everything we could think to put on the subject of the GMO’s construct, application, workings ethics and use. I am very excited to have this finished and submitted. I have also enjoyed learning about the science behind the construct and of the various conditions it could diagnose, as well as about GMOs in general.

The Retroviruses That Made Modern Man

Before I delve into this subject I must explain what exactly a retrovirus is. Most viruses (e.g. influenza) hijack the cell’s machinery (e.g. ribosomes) to self replicate after infection of a host cell. Retroviruses (e.g. HIV) instead insert their RNA into our genetic code using an enzyme called reverse transcriptase to convert its RNA into DNA for insertion into the host’s DNA. Once the genetic material has been integrated into the host cell’s DNA, the virus then uses the cell’s machinery to create the parts of the virus, which are assembled on the cell surface.

Where the retrovirus inserts its DNA into our genome is random. It then waits for the right moment to start virus production. This viral DNA can be copied along with the host’s (during cell replication), or it can be pasted into another random part of the genome. Over the course of millions of years, mutations cause the viral DNA to be unable to break free from the host cell’s DNA, however some of these endogenous retroviruses can still affect other parts of genetic code. This is because our cells use epigenetic marks to label and lock down the moving viral elements. But the viral genetic information can move with their marks, and so the viral sequences can spread to wherever they land.

About half of our genome comes from extinct viruses, which are collectively known as transposable elements, but are degraded beyond being virus-like.These large parts of repetitive and virus-derived DNA was thought to be rubbish, and some of it is almost certainly not much more than that, but other parts can form key triggers or serve key functions in the modern human and other spices too.

Professor Didier Trono and his team at the University of Lausanne, Switzerland believes that our bodies can harness the genetically embedded  viral DNA toward our advantage is to do with the main group of special silencer molecules: KRAB Zinc Finger Proteins (KRAB ZFPs). They lock down viral sequences in our DNA. There are over 300 different types of these molecules in our genome, each individual prefers a different virus-derived  DNA target. It used to be believed that they killed these rouge viral elements, but Trono belives that once attached to the viral sequence they suppress them and then eventually overpowers them. This idea is a bit controversial.

Some modern mammals have a syncitium (a special layer of tissue formed by fusing placenta cells). The molecule that does this is produced by a syncitin gene, which is very similar to the gene of a retrovirus. Another syncitin was later discovered, again it plays a part in forming the placenta, as well as this it also prevents the mother’s immune system from trying to attack the fetus in the womb. Humans, mice, cats and dogs all have their own two syncitin genes that do the same job, but that look as if they’re sourced from very different viruses. Horses and pigs don’t have a syncitium, nor do they have any syncitin genes from viruses; so they probably never caught one of the fusing viruses.

The University of Utah found an endogenous retrovirus in our genome that infected us 45-60 million years ago. This viral DNA has been used to help us fight other viruses. It does this by turning on the AIM2 gene when it detects an interferon molecule (the danger signal of a present viral infection). AIM2 then triggers the infected cells to self-destruct, preventing it spreading.

The PRODH gene is present in our brain cells, mainly in the hippocampus is also activated by the switch made from a long dead retrovirus. Chimpanzees share this gene and switch, although it is less used by them. Disfunctions of the PRODH gene have been linked to several mental disorders, so it is a key part of the brain. On the subject of chimpanzees, the genes that form and grow both our and their faces are nearly identical, so it is the switches (from viral infections) that are active in cells involved in this process that make the difference.

Andrew Campbell

The Teenage Condition

As it turns out, teenagers’ brains are unbalanced. Okay, so maybe it’s not that surprising. This is to do with the maturing of two parts of the brain: the limbic system (known for generating emotion and reward drugs) and the prefrontal cortex (which is where we imagine the repercussions or result if certain scenarios play out).

The limbic system develops rapidly in puberty. Its axons (long, thin parts of nerve cells that connect to body cells) become coated in myelin (a mixture of phospholipids and proteins); this permits rapid neuron transmissions.

The prefrontal cortex can often only become fully developed in a person’s twenties. It’s also used to navigate complex social situations. This imbalance means the teenage brain provides more pleasure, but less awareness. Which would explain the trend in a study that showed teenagers make more spontaneous decisions with less caution. This could perhaps be a natural mechanism to get adolescents to explore situations that they would learn from.

Another interesting part of the teenage brain is that the pineal gland has a delayed release of melatonin (the sleep hormone) from the normal 10pm in an adult to 1am. Since this is the major area of the brain for melatonin production..

Andrew Campbell

Creation

My group’s construct for our GMO has now been completed and submitted. This was made of a backbone, promoter, ribosome binding site, terminator and the gene that has the properties required for the GMO’s medical use.

The backbone consisted off all of the genetic information that wasn’t linked to the properties of the gene that we want expressed for medical use, and it took up the majority of the plasmid. This, the ribosome binding site and the terminator we had no choice in picking. However we did pick the promoter and special gene.

We chose the copper sensitive promoter. The promoter acts as a switch that is turned on or off under certain circumstances. This promoter activates when in the presence of Cu2+ ions. Certain genetic diseases (such as Wilkinson disease) make the body unable to control its copper levels by some homeostatic processes.

The gene we chose was blue chromoprotein, which is found in Acropora millepora as part of the Indo-Pacific coral reefs. It appears as a purplely-blue to the naked eye at its maximum light absorbance at 588nm. Together this means that if the promoter is triggered by a certain genetic disease then the blue/purple light will be showing. So our GMO will be able to be used to detect genetic diseases that result in the body being unable to maintain copper levels. It will even be an easy way for patients to monitor whether they need to take action to do with their copper deficiency/surplus.

Andrew CampbellScreen shot

An Opportunity

Good evening. Thanks to Medlink, I’ve the opportunity to work in a group to design a GMO (genetically modified organism) that can be used for real world medicinal applications. This will entail my group performing research on different genes and ideas on how to use those in a medical context. I will then write a paper on this work, which should then be published.

I can’t say what direction we will take with this, or all of the intricacies of what we will be doing, but I will inform you of our progress as I go along this process. Wish me luck!

Andrew Campbell

USB HIV tests

The Imperial College of London and DNA Electronics have collaborated to create a small, disposable HIV test that transmits the results through the USB stick to any computer with compatible software. It has an accuracy of 95% on over one thousand samples. This took an average of 21 minutes. This makes it better than most existing tests.

It works by taking a few drops of blood, and if the HIV virus is present then it starts a change in acidity, which is then electronically signalled to the USB stick using a mobile phone chip. It not only shows if the blood is HIV positive, but also at what stage the virus is in.

The goal is for it to be mass-produced in order to distribute to areas with few medical facilities, for example in remote locations. It can also be used by HIV patients to monitor their treatment.

The study author, Dr Graham Cooke said “We have taken the job done by equipment the size of a large photocopier, and shrunk it down to a USB chip.” This makes this seem all the more impressive an achievement.

Andrew Campbell

The Enteric Nervous System

Yes I know it sounds ridiculous, either because you think enteric is a made up word, or because you know it relates to the intestines (it wraps around the gut). However, this extensive network of neurons and neurotransmitters with brain-like complexity has been described as a “second brain”.

Its primary function (not that surprisingly) is to manage digestion. It is always in communication to the brain via the vagus nerve, 80% of which is dedicated to passing information between the enteric nervous system (ENS) and the brain.  The ENS has been linked to many disorders from obesity to Parkinson’s disease; and it it thought to effect our mood as well as the decisions we make.

According to Dr Emeran Mayer, and ENS specialist at the University of California,  “Your gut has capabilities that surpass all your other organs, and even rival your brain”. The ENS labels our memories of some situations (for example when one feel butterflies or queasy) with the effect they had on our gut. This can then be referenced as a quick-access library in a new situation to aid decision making. This may sound good. but it can be affected by your lunch so don’t rely on your gut feeling too much.

Serotonin is a neurotransmitter that’s been liked to depression for some time now; in fact, there are many drugs that aim to sort out a patient’s imbalance of serotonin. 95% of it is produced by the ENS, and it is a major area of research when scientists look into the ENS. This serotonin production is influenced by signals to the brain sent along the vagus nerve (also by what  we eat); so electrical impulses being sent along the vagus nerve can help severe depression. The ear is an easily accessible point to stimulate the vagus nerve externally, and a device (that’s low cost and not invasive) has been developed, and in pilot experiments has considerably lessened the severity of depression in patients. It is currently being tested to see if it will aid obesity.

An implant is being developed to keep track of diseases that are currently only diagnosable by their symptoms, such as irritable bowel syndrome. Which is currently being tested on animals.

I will leave you with another quote from Dr Emeran Mayor: “This second brain is made up of 50-100 million nerve cells, as many as are contained in your spinal cord.”

Andrew Campbell

 

Technology and Us

I love technology, as I’m sure many others do. Although it seems most tend to have a love hate relationship with it (or rather frustration than hate). So I wondered, how does technology truly affect us and our minds.

I found a few interesting things on this topic:                                                                                        The reason why looking at an electronic screen before bed results in a more restless sleep is because the blue light tells the pineal gland (roughly in the center of the brain) that it’s morning. This stops mlatonin (the “sleep hormone”) production.

The memory of gaming and internet addicts is affected. The grey matter, particularly in the frontal lobe (which is linked to planning and organisation), atrophy. This can make memories less vivid. Socially, social media use can affect people’s ability to interpret faces.

On a more positive note, children who use search engines, forums, online educational resources and play complex games are shown to have an accelerated learning rate.

I also found that the reason why you can feel phantom phone calls (when you can fell your phone ringing, but it isn’t really) is because we are so alert for messages that we misinterpret muscle spasms.

The most interesting thing I fund on this topic was that our multitasking has seemingly improved due to technology use, a perfect example of practice makes perfect. When we focus on one task, the hippocampus is used, and it permits comparison between old ideas and the new information to put what’s being learnt into context. However, multitasking uses the striatum, which stores procedures and skills. This means that knowledge acquired during multitasking is less embedded in memory.                                                                                   The small grey matter density in the anterior cingulate cortex (ACC) is linked to multitasking. This area of the brain is involved in empathy and decision making; and it is unknown whether a smaller ACC small grey matter makes a person more likely to multitask or if a multitasker develops a smaller ACC small grey matter.

Andrew Campbell

My Work Experience

Hello, although I cannot talk about the patients that I met and talked to in my work experience, I would like to share my conclusion of the second day (which was comprised completely of surgery observation). This is because we often assume when we go to the hospital a doctor does all the work, whereas in reality there are many people behind that doctor in order for him to function:

What this day showed me more than anything else was the teamwork required for surgery and medicine, and that everyone has a role. For example, during the bowel widening, it was the chief surgeon’s job to perform the operation, the other doctors were there to advise and supply him, and to keep everything as clean and sterile as possible; and it was the ward sister’s job to hold and give the chief surgeon the tools the other doctors had brought. No single act toward a patient was uncoordinated with another medical professional; be it in prepping the patient for surgery, or in the conversations occurring during the surgery and then deciding which route to proceed with.

Andrew Campbell

Good Morning

Hello, I am Andrew Campbell, a 17-year-old (year 12) student on my road to becoming a doctor. This blog’s main purpose will be to document and share my journey, but don’t be too surprised if I post about something just because it’s interesting. My hope is that people who want to aim for this career can take useful information and ideas from my path to help forge their own.

I’ve just returned from a weekend at Nottingham University where Medlink was being held, and thanks to that conference I now have the knowledge and confidence I need to complete the rest of this journey.  I would highly recommend looking into Medlnk if you want to go into medicine,  not only because of the inspiration and much needed advice it provides, but also because it helps you realize if you really want to become a doctor (or vet). Personally, I now am now certain that this is the right career for me, from the personal side to the science.