Growing Better

For years now Stem Cell research has been one of the hotter topics in new medical research. Certainly the media portrays stem cell research as the next miracle- working stage of medicine where we will be able to grow new livers cure all kinds of diseases and disorders.

But how close are actually to using stem cell research in practical healthcare?

In a letter published by Nature this week, a research group in New York, NY has given us a good insight into how far stem cell research has come. They have focused on using stem cells to treat Parkinson’s Disease, a well-known genetic disorder caused mainly by the death and degeneration of Dopaminergic Neurons in the Substantia Nigra. Dopamine is a neurotransmitter that is associated with a large number of functions, but is important in controlling movement. As Dopaminergic neurons degenerate this effects our control over our movement, hence the shaking symptoms associated with Parkinson’s.

The objective of the research is to see how effective using stem cells to grow new Dopaminergic neurons might be. This team took Pluripotent Stem Cells (PSC, the type of stem cell that can grow into anything) and exposed them to Wingless (WNT) and Sonic Hedgehog signalling molecules (SHH, also not a joke!) which directed the cells into becoming Mid-Brain Dopaminergic neurons. After 25 days of growth they had neurons that could be used in vivo (in actual living animals, as opposed to in vitro- in the lab).

Pluripotent Stem Cells: the type that can grow into almost any cell in the body

The study then used lesioned Mice and rats to simulate the effects of Parkinson’s (mice with part of their brain removed, this can then simulate Parkinson’s in animals). They reported that the subjects showed improved motor skills and less akinesia (uncontrolled shaking) in tests, suggesting that the implanted stem cells were improving symptoms associated with Parkinson’s.

All in all this is a remarkable and interesting experiment. They have shown it is possible to grow Dopaminergic neurons, maintain them for months in a living thing and even that they could be planted into monkeys. There is promise here that this treatment may also help to relieve the symptoms of Parkinson’s. Before we get too excited however there are still clear limitations: there are still safety concerns with Stem cells and we still have yet to try this in humans, a huge leap in research that I suspect will have to overcome massive ethical questions before it can go ahead.

Still, this experiment is one of many that suggests, one day, we might be able to grow ourselves better.

original paper:

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10648.html#/author-information

picture (from Popsci.com)

http://www.popsci.com/science/article/2010-08/mits-new-synthetic-material-allows-stem-cells-grow-without-adding-foreign-catalysts

Free to do what I want! …or not?

You’re standing in a department store and you’re shopping for clothes. There’s a big selection. Eventually you choose a new pair of Levi jeans, you had a lot of choice though.

Or did you?

What if the choices that you think you make have actually been made for you, several seconds before by your brain? What if, in fact, you had no Free Will?

Free Will is a big philosophical question, with passionate arguments on either side. Most people would assert that in their everyday lives they experience free will as they choose what they eat, who they talk to, how to get to work and what glass of wine they will have with dinner. But as our knowledge of how the brain works expands, Neuroscience may be slowly shattering the idea that we have control over our own lives.

A study done by Haynes and his group at the Bernstein Centre for Computational Neuroscience in Berlin has posed some challenging questions on this subject. Subjects were placed in an fMRI machine (a type of brain scanner that measures brain activity by tracking minute changes in blood flow) and shown a series of random letters. They were told to press a button in front of them whenever they felt like it, with either their left or right hand and to remember which letter was shown when they did.

Looking at the brain activity of subjects, Haynes was able to see that the conscious decision to press the button was made a second before the act, which seems reasonable. But he also found a pattern of brain activity that preceded the decision by as much as seven seconds. It seems that before the subjects were aware they had made a choice, their brains had made it for them.

These seem rather unsettling findings. The idea that our brains are making all our decisions for us is not a pleasing one. There have been other experiments such as this but it is too early to say that Neuroscience has killed our notion of free will. Future experiments will have to establish fully that these early pattern of brain activity really do result in unconscious decisions, rather than simply being part of a wider parallel decision making processes. Future studies will also need to apply simple lab tests to the complex decisions we make in real life.

Neuroscience hasn’t set out to destroy our long (and proudly) held view that as humans free will makes us special. But it is certainly asking some fascinating questions. 

link to paper via Nature Neuroscience:

http://www.nature.com/neuro/journal/v11/n5/abs/nn.2112.html

Faster than the Speed of Light?

Stunning new from CERN this week where physicists have released data from an experiment suggesting that fundamental particles, called Neutrinos, can travel at speeds faster than light.


This experiment has made front page headlines across the world because the findings seem to contradict Einstein's Special Theory of relativity, which is the cornerstone of all modern physics.


The findings still need to be properly reviewed by other research groups but should the findings stand they will represent a momentous change in our understanding of physics.


Physics isn't really something I understand much about, but certainly the prospect of more research coming from CERN and the LHC is pretty exiting, so I thought I'd share.


Nature article:
http://www.nature.com/news/2011/110922/full/news.2011.554.html

Original Paper:

http://arxiv.org/abs/1109.4897

Well Done Son

Attention Deficit Hyperactivity Disorder (ADHD) is a surprisingly poorly understood disorder considering its high prevalence. For many people, ADHD is an overused label conjured up by poor parents to explain their child's poor behaviour. Yet, ADHD is a common disorder with a strong genetic basis and seriously detrimental consequences in adults. Leaving treatment to one side, the most pressing and practical question concerning ADHD in children is how do we keep them focused in school?

A recent study on 182 4- year olds in Holland has found a surprisingly simple answer: tell them they are doing well. The study found that all children performed better in a learning task when receiving positive feedback, including children with ADHD, who performed even better than healthy children in some cases.

Why is this? Positive feedback triggers the release of the neurotransmitter Dopamine in the brain. The study used children with mutations to the Dopamine D4 receptor (DRD4) gene, which is known to be a mutation present in ADHD. The DRD4 mutation affects the structure of Dopamine receptors and therefore its transmission in the brain. It seems likely that this makes ADHD affected children more sensitive to positive feedback, hence their improved performance in the study.

So maybe a few extra 'well done's are in order. Science can be so simple.

Further reading:

New Scientist article:

http://www.newscientist.com/article/mg21028155.000-positive-feedback-gives-kids-with-adhd-a-head-start.html

Original paper:

http://onlinelibrary.wiley.com/doi/10.1111/j.1751-228X.2011.01112.x/abstract

Resistance is Futile

It has been 83 years since Alexander Fleming discovered Penicillin and started one of the most important revolutions in healthcare: The Invention of Antibiotics.
Yet less than a century later we are facing a crisis in the making. Bacterial Resistance has become so effective that new strains of Carbapenem -resistant bacteria have been discovered that are unaffected by the most powerful antibiotics we posses. How have we arrived at this stage so quickly?


Bacterial resistance is certainly not a new topic in medical research. As soon as we started using antibiotics frequently the bacteria have fought back, overcoming penicillin in the fifties, Methicillin in the eighties and even vancomycin in the 90's. For decades we have been embroiled in an arms race with bacteria who are able to rapidly evolve ways of fighting back against each new drug that we are able to develop. And now we have confirmed resistance to Carbapenems, the most powerful broad-spectrum antibiotics available to doctors.


Scientists have identified a new gene found in gram- negative bacteria, called NDM-1 (New Dehli metallo-beta-lactamase, after where the first case was hospitalized) which codes for a protein that inactivates any antibiotics that attack.

Gram- negative bacteria have now developed resistance to the Carbapenems

I guess we should not be surprised that bacteria have evolved to such a high level of resistance. While it may take 10 years to develop a new drug, bacteria can divide every 20 minutes. When these bacteria are multiplying in an area of such high antibiotic pressure as a hospital, evolution will favour that bacteria that develop resistance, and fast. Some bacteria also have the exceptional ability to transfer genes coding for drug resistance between them via their plasmid DNA, thus bestowing resistance upon new species that have never been exposed to the drug. 
We have also aided bacteria in their cause by liberally prescribing antibiotics for minor infections and by providing breeding grounds for superbugs with low standards in crowded hospitals. Now we may be on the brink of paying the price for our negligence.


Cases of such 'superbugs' are currently low, with probably no more than 1000 Carbapenem- resistant cases worldwide. But without proper precautions being taken, and without any new classes of antibiotics being developed, the near future is looking grim for our ability to treat serious infections.






references:
'The Enemy Within' Scientific American April 2011


Does broad-spectrum β-lactam resistance due to NDM-1 herald the end of the antibiotic era for treatment of infections caused by Gram-negative bacteria?


Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study


Gram- Negative Bacteria picture

Small but Extreme

I was planning on writing about the new genetic discoveries related to Alzheimer's today but something else caught my eye, and it just seemed more interesting.

http://www.nature.com/news/2011/110404/full/news.2011.207.html

Some Chilean scientists have reported finding over 300 new types of microorganisms during a recent expedition to the Antarctic. Not necessarily that interesting you might say except that some of the species they found were pretty damn cool: Microorganisms that can survive in extreme environments!

They found microbes that can survive in temperatures of below -15C and even above 95C. Microbes that can survive in  high levels of salt and at extreme pH levels. 

Microbes resistant to UV light was a particularly interesting one. The mechanisms behind that may provide an insight into protecting us from sun burn and consequently skin cancer.

It all doesn't seem that ground breaking but it left me pretty impressed with the utterly extreme conditions in which some microbes can survive, and certainly makes the idea of life on other planets not that hard to comprehend. 

PS: the two papers that were published on Alzheimer's the other day were pretty important. They found several new genes linked to the disease. Finding genes such as these is the first step in discovering whether there are any therapeutic treatments are possible.

the links to the two papers are below:

http://www.nature.com/ng/journal/vaop/ncurrent/full/ng.801.html

http://www.nature.com/ng/journal/vaop/ncurrent/full/ng.803.html

Good Science but Bad Journalists?

Science may be interesting but it is not often exiting. Test tubes don't really provide the same opportunity for media coverage that Z-list celebrities trying to ice- skate so clearly does. 

As such the media can often exaggerate scientific progress, 'Cure for Most Cancers 'Soon'' being a fantastic Daily Express FRONT PAGE (!) headline in January.

Scientific papers and journals are complex to understand, simply because they have to be otherwise the lack of detail would be useless to fellow researchers. But media have to put it simply because the public can't be expected to understand complex scientific ideas, and won't read something they don't follow anyway. 

The media has a duty to report the news fairly, and the science world has a duty to make itself accessible. I think that's fair don't you?

PS: The reporting of science in non-scientific media can still be notoriously bad. Check out Martin Robbins in the Guardian last year for a superb parody of this, complete with great references.

http://www.guardian.co.uk/science/the-lay-scientist/2010/sep/24/1

PPS: Nothing annoys me more than an article without a reference. It should be illegal.

REF:

The Lay Scientist, Martin Robbins, Monday 27 September 2010, 09.19 BST, guardian.co.uk   ... should be ok I think!

Because People Like Pictures

Everyone likes a good picture. Scientists like them too, explaining complex stuff is so much easier with a nice diagram to go with it.

Scientific imaging has made massive strides it what it is capable of showing us. We can watch the brain at work, see all the bones in our body and find that tumour that seemed to be invisible. Imaging can also give us some pretty cool pictures, so I put one behind my blog.

I got this image by typing 'Glial Cells' into Google and it is from the Encor Biotechnology website (their picture not mine!)

Glial cells make up most of the brain. While nerve cells carry the signals and do all the cool stuff, Glial cells provide them with the structure and nutrients for them to keep going, Fibroblasts are the main connective tissue in the body and are stained green. The star- shaped Astrocytes come out gold/orange. Astrocytes are pretty cool, they envelope the synapses in the brain and monitor their transmission. We don't really know much about them either, but it seems they might do more than just helping out the nerve cells. The blue dye reveals all the DNA in the nuclei of each cell.

Pretty picture hey? Shame i'm colour blind. I hate pictures.

on its original page:

http://www.encorbio.com/Album/pages/Chkvim-RGFAP-hoe-40X-3.htm

All you need is Love?

I would imagine that most people have to sit through their grandparents reminiscing at length over Sunday lunch. I would imagine too that most people would have heard the story of how their grandparents first met. "..and she's still as beautiful as the first time I saw her..." may have been the point that convinced you that you grandfather had lost it, or could it be that actually he really does think so?

It's nice to start things on positive note and this article seems like a good place.

http://www.ncbi.nlm.nih.gov/pubmed/21208991 (pubmed abstract).

The research here involves 17 people who had all been married over 20years, and showing them pictures of their partners (and people they didn't know as controls) and watching how their brains react using functional MRI. For the lay scientist fMRI is one of the most common imaging techniques. It measures hemodynamic activity in the brain ie. changes in blood flow. It works on the principle that if a part of your brain is working hard, the blood flow to that area increases to meet the increase in demand for oxygen, glucose and other nutritional goodies. In our experiment here, the fMRI allows us to see which areas of the brain light up in the subjects when they are shown pictures of their loved ones. Cool, eh?

The authors have noted quite a few areas of the brain that light up; hypothalamus and hippocampus are two areas you might have heard of. Some of the others, probably not. But hey, the brains pretty complicated. The most interesting area is the Ventral Tegmental Area (VTA),  where much of the Dopaminergic nerve cells originate. Ever done something that felt good? Chances are that your VTA was working in overdrive at the time. The VTA sends messages to almost everywhere and it's involved in motivation, addiction and reward (your VTA is why Galaxy Bars just taste so good).

The authors have read other articles that have done the same thing in people who have just fallen in love: the patterns look the same!

What the article is saying is that after 20 years these people are still getting the same sense of happiness when they see their partner as they did when they fell in love. How sweet. 

Nice to know there are people in white coats in NY researching this kind of thing. How interesting. Grandpa will be happy. Oh wait, he already is.

REF:

Neural correlates of long-term intense romantic love, Acevedo BP et al. Soc Cogn Affect Neaurosci, 2011 Jan 5th (Epub before print)