Penny Thoughts

Tag: health

Interactive Cell Signalling Experience

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http://www.cellsignal.com/reference/landscapes/mitochondria.html

The above url will send you to a website full of nice clear diagrams outlining the steps and molecules involved in lots of cell signalling pathways. Some representations are a little more interactive than others, including the one I have linked to. Aspects of processes outlined in this link are apoptosis (cell death), the degradation of cellular proteins via a pathway involving regulatory proteins called ubiquitin and respiration in the mitochondria. The picture itself provides an interactive opportunity to see the 3D structure of these molecules involved and where these processes take place. The way they have presented this cellular landscape is beautifully done and still maintains accuracy in terms of the processes and molecules involved. They are putting these really quite complex processes into a context that enables you to see more clearly what is going on and where it is happening in relation to other such processes. I really enjoyed having a good explore through these diagrams and pictures and it is nice to see these pathways being represented in a new and exciting way.

Could Young Blood Stop you from Ageing?

Research in the US has shown that injecting old mice with young blood leads to improved muscle strength, brain function and stamina; potentially reversing the effects of ageing.

3 studies were published last week in Science, all reporting on the rejuvenating effects of young blood in older mice. The young blood led to the appeared reversal of age-related declines in memory, learning, stamina and the function of many organs including the heart and brain.

Ageing is the underlying cause of a huge number of health problems. As our bodily systems slowly go into decline with age, health problems like dementia, cancer, heart disease and diabetes become more and more common. By learning more about the ageing process and its links with various health problems, we could predict, or even prevent many cases. Therefore, this research carried out in the US is of great importance.

In each study the researchers used a process called heterochronic parabiosis, which essentially involves joining two mice together; think conjoined twins. This process is carried out by making an incision on one side of each mouse and then allowing the wounds to heal in such a way that the two mice become joined. This process results in the joining of the two mice’s blood supply.

The researchers joined young mice (3 months) with older mice (18 months) and studied the effects of the new shared blood supply.  They found that brain function increased in the older mouse, as not only did the mice grow more neural connections (how brain cells communicate), these connections were also stronger. This means better communication between the cells in the brain of the older mouse.

Villeda, lead author of one of the papers told the Guardian “There’s something about young blood that can literally reverse the impairments you see in the older brain.”

From these initial findings Villeda went on to directly inject older mice with young blood plasma (blood without red blood cells), and what he found was remarkable. He tested the young and old rats’ memory and ability to learn using a water maze and testing their ability to remember a threatening environment.

The old rats injected with young blood plasma performed just as well as the six-month old rats in the maze task. Even more remarkably, the older rats performed as well as the three-month olds in remembering a threatening environment.

These results suggest that there is something in the blood of young rats that is essentially reversing or halting the ageing process in older rats.. so what is it?

The answer to that very important questions is Creb; a protein that regulates the brain. The young blood plasma actually increases the activity of Creb which in turn switches on the genes that create neural connections.

However, young plasma isn’t just improving learning and memory in mice. Further studies have shown that injected young blood also increases blood flow in the brain by encouraging blood vessel growth. There was also an increase in the growth of neural stem cells which later become new brain cells. It has also been found that young blood makes older mice stronger and boosts endurance due to increased muscle function. The young blood also led to the older mice gaining a greater sense of smell.

So this is all very exciting, but what happens if you do the opposite, and inject young mice with old blood? Well, interestingly the younger mice show the opposite results; they show decreased brain and muscle function and perform less well in memory and learning tasks. So the process works both ways.

So what does this all mean for us? According to Villeda, “The evidence is strong enough now, in multiple tissues, that it’s warranted to try and apply this in humans”. This potential research is however, not expected to take place until three to five years from now.

This is all very promising, and if the same is found in humans there could be a dramatic reduction in the onset of age-related health issues, which would be particularly important as the aged population in the UK continues to grow. Preventing the onset of these diseases would save a huge amount of money and potentially work to prevent the potential impeding public health crisis.

However, we cannot know for sure the impacts of this study on humans until clinical trials are carried out. So don’t go stitching yourself to your children just yet.. there is plenty more we don’t know.

 

Destiny’s Childless: The Pill’s Wanted and Unwanted Effects

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The pill has been letting women grab life by the balls instead of washing those of unwanted children for over 50 years. Roughly 100 million women worldwide take the pill and this has led to improved quality of living across the globe, huge reductions in numbers of deaths during childbirth and an understandably massive decrease in the number of unwanted pregnancies.

The pill acts by changing hormone levels to trick the body into thinking that it is already pregnant. This stops eggs being released from ovaries and leads to various gruesome sounding things like increasing your cervical mucus. The main aim is to make the womb a pretty inhospitable place for eggs.

So the pill has been having its way with women’s wombs for a long time and has played an important part in allowing women to have better educations and explore further into the working world. It’s unlikely that many female CEOs and even Destiny’s Child could have been such independent women if it weren’t for contraceptives like the pill.

However, along with these many female-empowering outcomes of the pill, there is evidence that the pill may be altering other choices that females make, including their choice of potential suitors and their sexual tendencies.

Normally, when women are not on the pill, they experience alterations in their mate preferences through their menstrual cycle. Research has shown that when women are ovulating, and therefore fertile, they show a strong preference for more masculine and dominant men. Whereas when women are not fertile they shift their preference to more feminine ‘good father’ type men who can look after them and provide them with resources, be it sandwiches or diamonds. So these changes in women’s instincts lead to the exploitation of men for either their potential to shower you with resources or to provide their fantastic genes.

This cycling has been put down as one of the key reasons why women tend to cheat more on their partners when ovulating. Women also tend to act in a more sexually promiscuous way when ovulating, so single men of the world, maybe it would be in your benefit to show some interest in the ladies’ menstrual cycles. However, these women are generally going to be seriously fertile, so kids… use protection.

Preference changes also occur in men in response to ovulating women. It has been shown that men are actually more attracted to women when they are ovulating, be it because the women are acting more confidently or that men are picking up on some kind of pheromone-type signal. So, what better way to test this idea than send a load of awkward scientists to a strip club? They basically looked at female stripper wages throughout their menstrual cycles and found that they earned on average $150 more when they were ovulating. This pretty ridiculous sounding fact is true; it’s been proven using numerous beloved statistical techniques. Therefore, I conclude that ovulation makes me (and all you other women) $150 sexier. So thank you to you ovulation for fuelling that questionably sexy dancing in clubs all over the world for many years to come.

All this normal cycling is altered when women are on the pill. Instead of having a change in mate preference, women on the pill are generally stuck in the ‘good father’ preference. As women don’t actually ovulate when on the pill, the switch in preference to dominant, sexy, genetically matched men does not occur or does to a much lesser extent.

The kinds of relationships that form when women are on the pill therefore tend to be with ‘good father’ type males. Questionnaires of these couples showed that they actually tended to be happier in their relationship and therefore they often lasted much longer than couples that met when the woman was not on the pill. However, a huge majority of these couples stated that they were disappointed with their sex lives and weren’t really very attracted to their partners.

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There are even further issues. Say, there is a lovely couple that got together when the girl was on the pill. They go through life fulfilling numerous dating and romantic clichés until finally he pops the question. What wonderful news! NO. Following this apparent joyous news the inevitable baby conversations are going to come up, and the decision to come off the pill commences. Problem 1: when women come off the pill they show a strong preference for the masculine, sexy male type. This is not the type of man our scenario husband is. This means that these kinds of couples have an increased chance of splitting up at this point when the woman comes off the pill. Problem 2: If the couple do stay together, questionnaires have shown that these couples are more dysfunctional, unhappy and have unfulfilling sex lives. So your options here are either, never have children, stay on the pill forever and continue with your lovely relationship, stop taking the pill and break up with partner or finally stay with your partner and grow into an old bitter couple that probably hate each other.

These problems aren’t even the end of it. As more women are on the pill than ever before, more woman are having to face these potential situations, and many are choosing to stay with their “good father” partner and having their children. These men are not as well matched genetically as those men they would naturally chose to make babies with and it has been suggested that this may lead to some detrimental health impacts in the future. Basically, those men that are better matched genetically have more genetic dissimilarities, particularly in term of genes involved in immunity. Therefore, if more women are having children with poor genetically matched men, there are likely going to be more children with worse immune systems than if women were picking men naturally without the pill’s interference. This could mean more allergy prone children and the potential increase in for example, cases of asthma. With the future for health looking already increasingly bleak with ever increasing waste lines and pint glasses, the addition of more sickly children is not ideal.

But please don’t worry, this is not the case for every woman and these negative health effects aren’t predicted to be severe. Also, if you did meet your partner while on the pill, don’t panic! This is not the case for everyone, you may be the lucky exception.

Are You A Slave To Your Inner Parasite?

You would think that you’re in total control of your thoughts and behaviours, but for some, this is not always the case..

These pretty pathetic looking purple things to the left are parasitic individuals known as Toxoplasma Gondii. The parasite causes Toxoplasmosis and can infect many hosts, but I will mainly be concentrating on the cat/rat life cycle and the potential to impact humans.

Basic Lifecycle of T. gondii:

Let’s start with the feline host. If an infected cat (pet or wild) defecates it releases oocysts into the environment. Oocysts are spores which contain the parasites; they can be very long lasting in the environment and become infective within a few days. If a rat comes along and ingests food contaminated with these oocysts, the parasite has entered its next host. Within the rat the oocysts quickly develop into tachyzoites which are the mobile and asexual form of the parasite shown here in the picture. These move through the rat until they locate neural or muscle tissue where they develop into bradyzoites (tissue cysts).

If this rat, containing potentially huge numbers of tissue cysts is ingested by the cat, the parasite has returned to another feline host. In the cat, the bradyzoites eventually develop into the oocysts and are released into the environment and so completing the life cycle.

For an illustrated version of the Toxoplasma Gondii life cycle or any other parasitic life cycle DPDx do great, visual diagrams.

Changing Behaviour

It is common to underestimate the effects single celled organisms can have on our health and wellbeing, I mean, what can one cell do that is so bad? Well the answer to that is A LOT. To help ensure that their life cycle is completed the parasites change the behaviour of the rat host. Rats have innate instincts and characteristics which cause them to avoid potential predators like cats. For example, if a rat can smell the odours given off by cats they will actively attempt to get as far away from this smell as possible or take shelter in a safe place. However, when infected with the Toxoplasmosis parasite this instinct changes, and rats instead are attracted to this smell and will persue it to get closer to the feline in question. So the parasite is actually changing the brain of the rat host so that its normal instincts are not only forgotten but also replaced by completely different and life threatening ones.

M. Berdoy,  J. P. Webster and D. W. Macdonald conducted a study investigating these behavioural changes brought about by the T. gondii parasite. The rats tended to show much more risky behaviour when infected with the parasite than without and in doing so increased their chances of being caught and eaten by a cat. These changes to the brain are considered to be the work of the bradyzoites in the neural tissue in the brain. By altering the behaviour of the rat host so that it is no longer as acutely aware of risky behaviour, places and stimuli means that the parasite is increasing its likelyhood of getting into its next host and surviving. The parasite has taken control of its host and is driving them to danger and potential death to ensure its long term success.

Changing Human Behaviour

The prevalence of Toxoplasmosis in the human population is between 20-80% depending on the region, which is potentially a very large proportion of some populations. It is predicted that roughly 80% of French people are infected, which is a huge amount of people. Cats are a hugely popular pet across the globe and have become one of the most widely invasive species in existence. With our relationship with cats becoming increasingly close the T. gondii parasite has found itself inside humans instead of its normal host range. Humans can become infected in a number of ways for example, by ingesting contaminated water or food (spores or cysts in undercooked meat), through organ transplants or from their mothers via the placenta.

alg_road-rageSo it comes to question whether these odd behavioural changes brought about by the parasite could potentially occur in us humans when infected. This concept has been studied quite a few times, but one good study was done by J. Flegr et alin which they performed a personality test (specifically Cattell’s questionnaire) on 224 men and 170 women. They found that the men and women who did have Toxoplasmosis did have altered behaviour. The characteristics that were seen to change as a result of the infecti0n were “Superego strength” (conscientious, moralistic), “protension” (suspicious/ jealous), “affectothymia” (outgoing/ warm), “shrewdness” and a “high strength of self sentiment” (controlled/ over powering). These behaviours are being brought upon by the parasitic cysts found in the brain tissue and like in rats are leading to more risky behaviours. Another study by J. Flegr et al. looked further into this concept at more specific situations and found that people infected with T. gondii are significantly more likely to get involved in car crashes than uninfected people.

Toxoplasmosis in Foetuses:

Besides these personality changes, an infection with Toxoplasma has no serious effects on those infected unless you are immunosuppressed. The big issues come in pregnancy. A normal infection is controlled by cells of the adaptive immune response, including crucially, cytotoxic T cells. These act by destroying cells that are infected with the parasite and so regulate the infection. The problem is that foetuses do not have these cells as they cannot be passed from mother to foetus, but the parasites can. Therefore, the infection cannot be controlled in the unborn child and this can have severe effects. If the mother has a T.gondii infection before or soon after conception the foetus is in nearly all cases miscarried. If an infection occurs later in pregnancy the chance of still birth is hugely increased. If the child does survive birth it is likely that the child will soon die and if not they  generally will have impaired vision and severe learning difficulties.

As these effects are so severe there are measures in place to detect T. gondii infections so don’t worry too much! Women are routinely checked for the infection when pregnant. If a woman does have an infection it is generally caught before the parasite could have spread to the foetus. These women are given drugs like spiramycin to control the infection and decrease the chance of spread to the foetus.

So next time you’re feeling particularly aggressive or risky maybe take some time to consider whether it is in fact you driving these emotions or if your inner parasite is taking control..