Elephants – how have they beaten cancer?

As the constant struggle to find a cure for cancer goes on  in the medical world, it’s no surprise that scientists have been studying organisms across the animal kingdom hoping to find some inspiration, and therefore it wasn’t long before the phenomenon of Peto’s paradox was discovered.

Cancer is caused by damage to the DNA of a cell or cells in an organism, which causes disruption to the cell cycle, and constantly causes the abnormal, uncontrolled growth of a mass of cells which we know as a tumour. Given that cancer can arise from any cell, it would follow that organisms with a larger number of cells would experience cancer at an increased rate, yet it seems this is not the case. Whilst one in four people with cancer will die from it, only around one in twenty five elephants who have cancer will die, and the occurrence of cancer in elephants is significantly lower than in humans, so what is their secret, as surely an organism with 100x the number of cells should experience cancer 100x more frequently.

So what is their secret, decreased exposure to carcinogens? Skin better at preventing harmful UV light penetrating and damaging their skin? No, it all comes down to the tumour suppressor gene, p53, of which humans have 2 copies, and some elephants have as many as 40. The function of the p53 gene is to activate a protein which either stops cell division and repairs corrupted DNA, or induces the process of apoptosis – cell suicide. It also has the ability to limit blood flow to tumours to halt growth and can alert nearby immune cells to attack the tumour. Because elephants have so many copies of this gene, it appears that they are very good at tackling tumours and consequently cancer caused deaths are very much a rarity for elephants.

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The so-called ‘smart’ bandages

Work conducted at Swansea University’s Institute of Life Science is aiming to produce a bandage which can detect how wounds are healing and convey this information to doctors.

Through a combination of 5G nano-technology, which can sense the state of the wound at any given time, and the use of smart phones, to relay information about where the patient is and how active they are, this concept will provide doctors with a vast amount of information they never previously were able to have, and could help identify not only when a wound has healed fully, but also if there are early signs of infection, which may delay healing. Consequently, if the infection is treated with antibiotics before it becomes a problem, then it would speed up healing the for the patient, mean the wound is less likely to cause potential problems in the future, and save the NHS money in caring for the patient.

This is a very exciting idea, as it would allow clinicians to tailor treatment to the wound and individual person. In addition, if trials of the bandage are successful, it could also pave the way for bandages which are able to treat patients (for example, bandages with gel could react to environment surrounding wound and detect whether more gel needs to be released to hydrate wound more, or if gel needs to be reduced).

Such bandages could be produced by 3D printers to reduce costs, which again would benefit the NHS massively.

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Mass production of rare blood types

A team at Bristol University and NHS Blood and Transplant have managed to develop a method which allows them to produce an unlimited supply of red blood cells. Whilst it was previously possible to produce red blood cells in a laboratory, the cells died after producing around 50,000 cells (on average, adults have between 20 and 30 trillion red blood cells at any given time).

The new technique involves ‘trapping’ stem cells in an early stage, at which point they can grow and multiply indefinitely – essentially the stem cells have been made immortal. After a suitable quantity of cells has been produced, researchers trigger them to differentiate and become specialised as red blood cells.

Whilst there are no plans to stop using donated blood, such a technique could help when it comes to providing blood transfusions for people with a very rare blood type, as it is often very difficult to source rare blood types in such large quantities. One example of this is people from ethnic minorities, in which it can be almost impossible to match blood types. It also removes the risk of passing on diseases transmitted in the blood, such as HIV, malaria and septicaemia (although this isn’t really a problem).

However, there is a great cost associated with the production of these cells, and so it is unlikely that, at least for the time being, that these cells will be used on anything other than patients with very rare blood types.

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The Tsimane People

Recently, it was suggested that researchers have found a population with the healthiest cardiovascular system in the world, and it’s in the Amazon Rainforest – Bolivia, to be precise.

The Tsimane are a group of people who live, hunt and fish in the Bolivian lowlands of the Amazon Rainforest, and after extensive research, scientists have concluded that these people have the healthiest hearts in the world. So what is the secret: genetic protection? natural selection? medicine that offers immunity against CVD? No, its none of these things. The secret of the Tsimane people is that the hunter-gatherer lifestyle they lead is very healthy, and whilst it may not be practical for us in the UK to adopt this lifestyle, we can definitely learn some things from them.

Let’s look at their diet; they have a very high calorie intake from carbohydrates – almost 3/4 of their energy comes from rice, maize and a vegetable called manioc, which is similar to sweet potato. Then, some of their calories come from fat (14%) and the rest from protein. Secondly, they are far more physically active, with each person in the tribe averaging 16,500 steps a day, whilst here in the UK, the average person would achieve just under 10,000. Finally, and unsurprisingly, they some significantly less, meaning their bodies are not exposed to the huge number of chemicals found in cigarettes.

So can we learn from them? What has been concluded from this research is that the good diet and the lack of smoking places the Tsimane in good stead, but the exercise is believed to be what makes the biggest difference between their hearts and the hearts of people in the UK; whilst we may train intensely at the gym three times a week, and then sit down for six hours straight at work, the Tsimane are almost constantly on the move, so scientists suggest introducing exercise into smaller aspect of life, such as walking / cycling to work everyday, or simply using the stairs instead of an escalator.

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Stem cells – what are they, and how can they help us?

After my most recent post on multiple sclerosis in which I discovered that stem cells have the ability to prevent the MS from progressing any further, I decided to look into stem cells a bit more in order to gain a better understanding of what they are, and how they can benefit medicine in the future.

What are stem cells?

Stem cells are found in multicellular organisms, and they have the ability to differentiate and become specialised. In addition, they can also undergo mitosis to produce more stem cells. There are two main types: embryonic and adult (somatic) stem cells.

Where do they come from?

Embryonic stem cells – these cells come from the embryo when it is only 4-5 days old, meaning it contains only 100-150 cells at this point. At this stage, the embryo is known as a blastocyst, and consists of an outer layer of cells (trophectoderm), and an inner mass of cells which are undifferentiated.

Adult stem cells – such cells can be found throughout the body, and will remain in a quiescent (inactive) state until activated by disease or damage to tissue. Whilst most commonly found in the bone marrow, these stem cells can also be found in tissues such as the brain, the blood, the skin and the liver.

Uses

Stem cells now have a huge number of uses, given that scientists have figured out how to successfully remove them and encourage them to differentiate into all kinds of cells to treat all kinds of diseases and illness through growing new tissues or even entirely new organs (for example a trachea to replace one that had been blocked by a tumour).

Multiple sclerosis – multiple sclerosis is a degenerative disease caused by a fault in the immune system which causes it to attack nerve cells, damaging or destroying the myelin that coats them. However, scientists have managed to create a therapy which can prevent the MS from progressing any further (although it is unable to reverse damage already done). It is known as autologous haematopoietic stem cell transplant, and involves using chemotherapy to destroy the old immune system, and then using the patient’s own stem cells to produce a new one.

Whilst this remains a relatively new therapy, so far it has been a great success, and extensive research has shown that there are no long term effects and that MS does not return.

Treating burns victims – patients who have suffered extensive burning may be able to improve healing of the wound, reduce the formation of scarring and potentially even restore sense of touch in skin through use of stem cells. There is a large source of stem cells located just below the skin, which can be taken from a healthy area on the body and grafted on to the damaged area to engineer new skin tissue. The severity of the burn and how deep down the cells affected are depends on how much function of the skin can be restored.

Cancer – given that cancer is caused by the abnormal division and cell differentiation of cells, studying stem cells will give a better understanding of what causes a cell to differentiate and the signals it receives a releases during this process. In the future, this could allow scientists to learn what triggers tumours to form, how to stop them, and potentially how to identify cells which could cause tumours in the future.

Stem cells are also being used to treat cancers such as leukaemia, in which high doses of chemotherapy may destroy not only a cancerous tumour but also the healthy stem cells in the bone marrow. Doctors can harvest healthy stem cells from the patient or a donor and then put into a vein after a high dose treatment to replace the ones lost.

Ethics

Whilst the use of adult or somatic stem cells is generally considered to be ethically acceptable, there remains a great deal of controversy over the use of embryonic stem cells. This is because it involves creating multiple embryos to then destroy them, and many people are against this because they view it as killing an unborn child. However, others argue that because the embryo cannot feel anything and is not truly a child yet, that it is morally acceptable to use stem cells taken from an embryo.

There is an additional argument similar to the concept of ‘lesser of two evils’, in which people argue that whilst it may kill an embryo, it could save the life of someone who already has been born, although this is also a controversial argument in itself, as some say that it is immoral to value the life of one person over another.

In Japan, 2006, scientists managed to create their own embryonic stem cells, called induced pluripotent stem cells or iPCS and this could solve the ethical problem as no embryo loses its life in their creation. Despite this however, some scientists argue that iPCS are not quite the same as embryonic stem cells, and consequently, cannot yet be used in place of embryonic stem cells.

 

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Multiple Sclerosis

At school this week, we were asked to use the NHS website to summarise and present on a specified disease, and I was given multiple sclerosis, so I decided to post the backbone of my script, as I found it very interesting. Enjoy:

So what is multiple sclerosis?

The NHS website defines multiple sclerosis as a condition which can affect the brain and/or spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation and balance.

The disease affects over 100,000 people in the UK and is commonly diagnosed in people who are in their late 20s to early 30s. As a result of higher levels of the blood vessel receptor protein S1PR2, multiple sclerosis is four times more prevalent in women than in men, and I talk about this a bit ore later on.

Currently, it is considered incurable, although many of the symptoms can be treated to improve the quality of life for the patient.

What are the symptoms of multiple sclerosis?

The symptoms include, although are not limited to: problems with balance and muscle coordination; difficulty thinking, learning and planning; vision problems, and muscle stiffness and spasms.

The two types of multiple sclerosis:

Relapsing-remitting

In over 80% of cases, the multiple sclerosis patient suffers from what is known as relapsing-remitting MS. This means they suffer episodes known as relapses, in which the symptoms gradually worsen over a period of time that can range from a few days to several months, and then slowly improve over a similar period of time. These relapses can occur without warning and for no reason, although high stress levels or serious illnesses are thought to trigger them. Periods between relapses are called remission, and during this time, the patient can lead a relatively normal life. Unfortunately, later in life, this type of multiple sclerosis develops into secondary progressive (see primary progressive for symptoms).

 Primary progressive

Just over 1 in 10 people have primary progressive MS, in which, once the symptoms begin, they get worse and worse, and begin to accumulate along with other symptoms and consequently the health of the patient will deteriorate over time Although the life expectancy is not much less than that of a healthy person, the latter half could become painful, and this can be very upsetting for the family and friends to witness.

What causes multiple sclerosis

Multiple sclerosis os caused by an abnormal immune response, in which the immune system attacks the myelin coating nerve fibres in the CNS, causing damaging and scarring. This results in the nerves travelling much slower, or prevents them from getting through at all. Women have more S1PR2 protein receptors, which are involved in regulating the passage from the blood stream to the brain, which therefore enables immune cells to get to the brain and attack myelin. This is believed to be why there is a higher occurrence of multiple sclerosis in women than in men.

Treatments

Steroid medication to speed up recovery from relapses

Specific treatment for individual symptoms

Disease-modifying therapy to reduce number of relapses

 

Autologous haematopoietic stem cell transplant

There is also now a new treatment which can stop the progression of multiple sclerosis. It involves using chemotherapy to destroy the immune system, and then rebuilding it with stem cells harvested from the patient’s own blood, in the hope that it will produce a new healthy immune system which does not attack the CNS. Despite this, there are very high risks associated with this therapy, as it requires using toxic drugs in the chemotherapy which could have very harmful effects if procedure went wrong. However, in spite of the risks, a study carried out thirteen years ago has indicated that patients who underwent this therapy have experienced no long term effects and are now able to live normal lives free of multiple sclerosis.

 

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NHS Bed Shortages

Whilst we have all known that the NHS has been struggling to stay on its feet for a long time now, it appears that 2017 could be the year it finally crumbles, with 9 out of 10 hospitals reporting unsafe numbers of patients on their wards this winter, and record numbers of patients having to wait for longer than four hours for A and E care. It seems that the majority of the problems the NHS are facing stem from the our ageing population; for example, more and more operations are being delayed, and sometimes even cancelled as a result of there being no beds available for patients to recover in, primarily caused by elderly patients being unable to return home due to a lack of social care. Despite figures showing that only 1% of operations were cancelled last minute, this translates to just over 82,000 operations in 2016. Given that the NHS needs to be making the most of their resources, it seems like a terrible waste for surgeons to be sat around waiting, unable to perform their operations for something so trivial as a lack of beds.

Yet what can be done? It is simply not acceptable to just start discharging patients in an effort to free up more space, in the hope that they will manage just fine at home, and with so many elderly patients, this is often not possible anyway. GPs have been told they need to become open 7 days a week, and also need to advertise this fact, or they risk losing their funding, which is a positive start, although there are concerns over whether there will be enough trained staff available for this to be feasible across the country. In addition, much more funding needs to be directed towards caring for the elderly in all communities; allowing them to live comfortably from home should hopefully ease some of the pressure on the beds in the hospitals.

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Is camping the way to improve our sleeping habits?

Following research at an American University, evidence has come forward to suggest that spending a weekend camping in the great outdoors will have a positive influence on our ability to sleep better, as well as help those who struggle to get up in the mornings.

The reason being appears to stem from our natural body clock, which helps to regulate our  physical strength, mood, alertness, and when we feel tired, along with many other things. Scientists believe that the level of light helps our body clock to ‘keep time’ as it were, allowing it to anticipate when we may start to feel tired, and preparing our body for sleep in the evening, and vice versa in the morning. However, given that our lives not only revolve around, but have now become nearly dependant on technology, artificial light appears to be interfering with and altering the way we sleep. This is more noticeable in younger generations, and in teenagers especially, who now spend on average up to two hours a night after getting into bed on smartphones or laptops, meaning they are still wide awake long after their circadian clock says they should be asleep.

Not only does this offer one explanation for why some teenagers are so inexplicably tired throughout the day, and struggle so much to get out of bed in the morning, but also provides a suggestion as to why there are increasing cases of type 2 diabetes in younger patients and more issues with obesity (however this is almost certainly not the primary cause – easy and cheap access to sugary and fat filled food is the chief suspect).

Abandoning technology and modern life regularly for a weekend out in the countryside appears to be a great way to combat this struggle, as it would expose our bodies to more natural light in the day time, and less light at night, helping to reset our circadian clocks, providing us with a boost of energy and an apparent ease in getting out of bed in the morning. Despite this however, researchers added that this would not offer a permanent solution, and more drastic changes need to occur if people want to see a true and lasting improvement in their sleeping habits – examples of this include minimising our use of technology, but with modern life as it is, this may not be possible.

A study conducted in 2014, credited to scientists from Oxford University, suggested that people nowadays sleep between one and two hours a night less on average than people did sixty years ago. It was argued that this was potentially the result of human arrogance combined with the effect of technology on our sleeping patterns – humans believing that they could overcome our natural body clock, casting aside 4 billion years worth of evolution, in order to feed their addiction to phones and social media. Yet despite this, society continues to flourish, and we are living life at its easiest, so is sleep deprivation really causing us a problem? Or are we just more aware of the negatives than the positives?

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Mitochondrial DNA

Despite the majority of DNA being stored as chromosomes within the nucleus of every cell, there is a fraction of DNA found in mitochondria, known as mitochondrial DNA, or mtDNA. It contains 37 genes which are all involved in allowing the normal functioning of the organelle, with 13 being involved in producing enzymes to carry out oxidative phosphorylation (energy / ATP production) and the remaining 24 carrying instructions for making transfer and ribosomal RNA.

MtDNA is inherited exclusively from the mother, as it is transmitted through the female egg, and will be passed on to both sons and daughters, but only her daughters will be able to continue passing it on. Given that mtDNA is considered nonrecombiant (does not combine with any other DNA), it remains virtually unchanged through the direct maternal line over hundreds and even thousands of generations. Consequently, many people will have almost identical mtDNA, which suggests they share a common maternal ancestor. As a result, mtDNA is almost completely useless when it comes to determining biological parents, as there is no connection between a father’s mtDNA and his offspring’s, and many women have very similar mtDNA, making it almost impossible to distinguish a difference. Only in certain circumstances, such as the offspring having completely different mtDNA to their supposed mother, is it useful in determining biological relations.

Disorders and diseases caused by mutations in mtDNA often affect multiple organ systems, and more specifically have the greatest effects on the organs which require the most energy, e.g. the brain or the heart. One example of  disease caused by mutations is Leigh Syndrome, which is a severe neurological disorder.

Symptoms usually present themselves within the first year of life, although there have been reported cases of patients being in early adulthood before any sign of Leigh syndrome becoming apparent. The first symptoms commonly include vomiting and difficulty swallowing, resulting in stinted growth and issues gaining weight. In addition, movement becomes more and more difficult due to muscle weakness, involuntary muscle contractions, and trouble with maintaining balance. In more advanced cases of Leigh Syndrome, muscle weakness may also affect movement of the eyes, and severe breathing problems which may result in acute respiratory failure. Sufferers of the disease tend to only live for a few years, often dying as a result of respiratory problems.

Whilst the majority of Leigh Syndrome patients inherit it through an autosomal recessive pattern, in which both parents are carriers, around 20% of cases are caused by a mitochondrial pattern. Such cases are inherited from the mother only, and whilst it is not certain that children will inherit the disease, the chances are fairly high. This is the reason that last year, for the first time, a baby was born in Mexico and was declared to be the biological child of three people – two mothers and one father. The technique, pronuclear transfer, with which the embryo was created, aimed to prevent the mother of the child passing on any mitochondrial DNA, to remove the risk of passing on Leigh Syndrome.

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Three parent babies!

This week I was incredibly excited to hear that a second baby with there parents has been born in Ukraine through a complex IVF procedure. The first three part baby was born last year in Mexico to avoid the conceived child suffering from Leigh Syndrome (a severe neurological disorder that causes progressive loss of movement and deterioration of mental functions), which would have eventually proved fatal.

In Mexico, the technique to create the baby involved removing the nucleus from one of the mother’s eggs and inserting it into a donor egg with its own nucleus removed, and this egg was then fertilised with sperm from the father. Mitochondrial DNA from the donor egg is what means the child has three biological parents. However, this was slightly different to the method carried out by the Kiev team in Ukraine, who fertilised the mother’s egg with the father’s sperm, and then transferred the combination of genes into a donor egg.

Originally, the concept of three parent babies was designed to help women who carry mitochondrial diseases have healthy children, but the method was adapted for the couple in Ukraine, who were previously infertile, to enable them to start a family of their own.

Despite this being an incredible medical breakthrough, there is a lot of controversy surrounding this issue; for example, whilst here in the UK there have been three laws passed to allow the creation of babies from three people, UK experts argue that the two procedures that have occurred so far have been highly experimental, and question the ethics of allowing people to create babies in the way.

On one hand, it can be argued that this medical breakthrough is something we should celebrate – it proves just how far we have been able to push the boundaries of science, and it has already allowed us to help two families have a family of their own, something that was previously unthinkable. As well as this, it will enable us to push the field of genetics even further in the future, and could help us to completely remove some genetic conditions, which previously have been untreatable or even fatal.

On the other hand however, given that we have not had the chance to study someone before who has grown up with three biological parents, it is difficult to predict whether the child will be able to live a healthy life – there is always potential for something within their DNA to go wrong. Also, it could lead to complications with guardianship of the child in the future: what happens if the child is orphaned – does the third parent have a duty or a responsibility to care for the child? Moreover, as with the arguments against IVF in general, many religions argue that the creation of an embryo by mechanical means goes against nature, and some believe that to interfere in procreation is to act as God. Furthermore, what about the child themselves – they will grow up knowing that they are part of a scientific experiment, and how will they feel knowing that they have three biological parents? They may even face prejudice at school and later on in life from people arguing that they shouldn’t exist. Finally, whilst we may be able to eradicate some genetic diseases, there is potential that we could create new ones, exposing generations after us to diseases that they would not have suffered from had we not interfered with genetics to begin with.

I hope you have found this enlightening, and if you have any views you would like to share, please leave a comment.

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