The first paper can be found in Science Translational Medicine and explains some of the coolest science being performed right now. Researchers in Boston have developed a personal cancer vaccine for patients who suffered from acute myeloid leukemia (AML). Leukemia cells were isolated from patients with AML and fused together with dendritic cells (a type of immune cell that creates antigens which help the immune system recognize the stuff that shouldn't be there, like viruses and other cancer cells). These hybrid cells, part cancer and part immune, were injected back into AML patients who were in remission after successful chemotherapy treatment. The idea is that these hybrids would teach the other immune cells in each patient how to recognize the antigens from their own cancer and help them root out any leukemia cells that survived chemotherapy...thereby preventing recurrence of their cancer. Twelve of the seventeen patients have remained relapse-free for over four and a half years! Although some patients did relapse after this therapy, the rate of success warrants a closer look at this approach as a means of combating relapse or even as an initial treatment of metastatic cancers. The technology will need to be refined but this proof of principle in actual cancer patients is an awesome development.
The next paper investigates how animals experience time and I have to say, it's about time I started talking about time considering this blog is called Ripples in Time. Researchers in Portugal used drugs and optogenetics to manipulate midbrain dopamine neurons in mice to identify changes in their perception of time. (Quick refresher: Dopamine is a neurotransmitter that is involved with reward and behavior [among other functions] and optogenetics is the manipulation of the function of cells in live animals using fiber optic cables and light.)
Researchers found that dopamine neurons in the midbrain are directly involved in judging periods of elapsed time, either when the neurons are stimulated to release dopamine or suppressed. Since neural circuits are way beyond my expertise, I'm going to quote the end of this article to get the point across. The writing in brackets are my own to help clarify:
"Situations in which DAergic [dopamine neuron] activity is elevated naturally, such as states of high approach motivation, response uncertainty, or cognitive engagement are associated with underestimation of time. Conversely, situations that decrease DAergic activity, such as when fearful or aversive stimuli are presented, are associated with overestimation of time. These observations, together with our data, suggest that flexibility in time estimation may confer an adaptive advantage on the individual."
-from Soares et al., Science, 2016.
This is direct evidence that the neuronal activity of some of the dopamine neurons in animal brains directly affect how we experience the length of time of events. So when I went to see Star Wars Rogue One I didn't even notice the movie was over two hours long because I was so excited while watching...whereas when I vacuumed the house earlier this week it felt like it took forever because my 'cognitive engagement' was low. Our perception of time is directly related to how stimulated we feel. This is cool stuff and may suggest how different people experience the timing of the same events in different ways. The results of this study also implied that the changes in perceptions in time were altered on the scale of actual seconds. This got me thinking. Maybe it isn't the Force that gives Jedi their ultra-fast reflexives, just really efficient dopamine neurons. But I digress...
The third paper is an oddball, which I've tried to incorporate into each of these posts. Scientists in Europe used satellite data to measure changes in land surface water over the entire globe between 1984 and 2015. The satellite imagery had a resolution of less than 100 feet, which is pretty incredible, and this a first of its kind survey. A few summarized points of the findings:
-Globally, land-surface water has increased almost 94,000 square kilometers (about the size of Lake Superior, according to the researchers)
-The addition of this surface water is evenly distributed among the continents and linked to locations with reservoir building, dam construction, and are perhaps even influenced by changing local climates
-Over 70% of surface water loss was concentrated in the Middle East and Central Asia and linked to drought, river diversion and other human activities
I wanted to highlight this paper for a variety of reasons. I agree with the authors that this type of open-source mapping of available water resources is essential for the sustainability of clean and available water in the future. I think it is also smart to recognize that water loss and gain is influenced by human activity, drought, and maybe even the changing global climate, and charting the areas where the greatest changes are occurring can help predict areas that will need help in the future. Imagine in thirty years if the Middle East and Central Asia lost almost all of their surface water and the problems that could pose socially and politically.
My main problem with this paper is that the authors try to present this data and incorporate their own commentary on climate change. I think that climate change is inherently a major influencer of water availability in our world...it would be foolish not to think so. But the presentation of this data, particularly in the abstract, was written in such a way to first highlight the loss of global surface water and gloss over the fact that surface water actually had a net gain. I felt it was poorly worded and emphasized the wrong aspects of the data - the most important findings being the location and availability of surface water and where in the world changes in local climates (droughts) and human activity (dams) play a major role in this critical resource's availability and its management. It's a small, nit-picky critique, but it rubbed me the wrong way.
Oh well.
The last paper focuses on CRISPR (again!). I've talked about this technology in my last few posts and I feel it is so important that everyone understands the implications that I'm going to close my 2016 discussion about this topic. This time I'd like to feature a paper that came out in Cell and identifies natural compounds that inhibit Cas9, the essential enzyme component in the CRISPR gene editing system. Remember, the CRISPR system is a type of naturally-occurring immune system for bacteria which is applied against invading viruses that infect those bacteria. Inside the CRISPR gene system for the bacteria Neisseria meningitidis, researchers found three genes that code for proteins that inhibit the activity of Cas9 and therefor the CRISPR system. Several genes, related in function, are also found in the genomes of bacteria-infecting viruses. Together, this means that viruses have evolved a way around the CRISPR system and now those genes are being shared (and evolving on their own) between bacterium.
The great news is researchers now have a way of inhibiting the CRISPR gene editing tool in animal cells with a natural protein found in bacteria. These proteins can be used as a drug/brake-system to limit off-target effects of CRISPR usage, protect specific tissues from being edited, and a way to prevent unforeseen downstream complications that may arise when using the CRISPR system in humans. I've long been concerned with the lack of restraints on the usage of CRISPR technology but the discovery and use of these enzymes is a step in the right direction with respect to control and safety.
Wooo hoo! #science.
So that wraps up 2016. When I'm finished with teaching in January I'll write a few detailed posts about some controversies in science...starting with the reproducibility crisis. Until then, I wish you all a very wonderful and happy New Year and a great 2017!
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