As the end of 2019 nears, we look back at the many impactful scientific breakthroughs of this past year. We hope this collection will inspire others to continue on their quest for knowledge and discovery.
Cellular Function can be Restored in Pig Brain Hours After Death
The brain is a mesmerizing organ due to its complex structure and function. Multiple studies show neuronal decline and death is inevitable after lacking oxygen for a very short period of time—in a matter of minutes. However, this amazing organ has managed to stun scientists once again showing that neurons can indeed regain some function hours after death and after blood flow has been interrupted for hours.
Earlier this year scientists at Yale published their study where they isolated the brains of 6-8 month old pigs (obtained from the slaughterhouse) and connected them to a system called BrainEx, which allowed perfusion of the pig brain with an artificial substance containing oxygen. Perfusion successfully restored circulation in brain tissue, which also resulted in preservation of neuronal structure including that of cells in the hippocampal region. Surprisingly, connection with BrainEx also helped restore neuronal electrical activity and inflammatory response. Furthermore, neurons were able to use oxygen use and metabolize glucose. It is important to note however, that perfusion did not result in complex and organized neuronal function such as awareness or perception.But, this study does challenge our thoughts on the meaning of death and how that relates to complex brain function. Moreover, this study presents the invention of an important tool that can be used to answer our questions about the human brain.
A Possible Cure for HIV
This story begins in 2009 when scientists reported a person, then known as the ‘Berlin patient’, had been declared HIV-free after receiving a hematopoietic stem cell transplant (bone marrow transplant). Prior to the transplant, this person had been living with HIV, taking HIV medications, and had developed acute myeloid leukaemia. Treatment of the cancer consisted of replacing this patient’s cancerous white cells with healthy white cells carrying a homozygous mutation in C-C chemokine receptor type 5 (CCR5), a receptor found on the surface of white blood cells that HIV binds to and uses to enter and infect cells. The mutation rendered the cells HIV-resistant allowing the ‘Berlin patient,’ now identified as Timothy Ray Brown, to defeat HIV. Brown’s remission from HIV, which has lasted 10 years, gave hope to many suffering with this deadly virus and its related conditions. However, this remained the only case of cured HIV for years.
Dr. Ravindra K. Gupta and colleagues reported earlier this year that a second HIV-positive patient, this time in the United Kingdom, has been in remission for at least 18 months after going through stem-cell transplant due to a Hodgkin’s lymphoma diagnosis in 2012. Similar to the ‘Berlin patient’ case, the donor cells also carried a CCR5 mutation. This second observation of a possible HIV cure shows that curing Timothy Ray Brown is not an isolated case and gives millions of HIV patients hope. The cure of HIV may be soon readily available and may require only a transplant with CCR5 mutation-carrying cells.
HIV virus attacking cell
Apidima 1 and 2: Changing our Understanding of Human Evolution
Recent analysis of two fossils discovered in 1978 has revealed novel information about human evolution and migration patterns. These specimens were found in Apidima cave in Greece and were named Apidima 1 and Apidima 2. Unfortunately, when first found, Apidima 1 only consisted of a fragment of skull. However, Apidima 2 was better preserved and consisted of an almost complete face. Reconstruction and comparative analysis led researchers to conclude that Apidima 2 lived about 170 thousand years ago and had Neanderthal features. Whereas Apidima 1 lived more than 210 thousand years ago and had modern human (Homo sapiens) features including a rounded posterior cranium. These findings indicate that early modern humans might have come in contact with Neanderthals. In addition, this data challenges the accepted idea of human evolution and migration indicating that modern humans spread from Africa at an earlier date.
The Threat of Rising Sea Levels
Scientists at Climate Central have found their model shows that the homes of 340 million people will succumb to sea-level rise by 2050. The study published earlier this year in “Nature Communications” presents estimates obtained using a digital elevation model, CoastalDEM specifically, which uses a neural network (algorithms modeled on the workings of the human brain). Scientists used CoastalDEM to correct for errors in models previously derived using a different DEM; NASA’s Shuttle Radar Topography Mission (SRTM). Startlingly, the more accurate CoastalDEM models indicates SRTM models vastly underestimated the number of people that will be displaced and affected as a result of rising sea levels and flooding in coastal areas and signals to an even more dire need to address climate change.
New and Improved CRISPR Technology – Prime Editing
A new and improved CRISPR technology called “prime editing” has emerged this year. Andrew V. Anzalone and colleagues have designed a Cas9 protein that so far shows it can precisely target and edit DNA sequences in human cells. Specifically, this technology seems to bypass the introduction of unwanted mutations as past CRISPR technology did with the help of a new Cas9 endonuclease, a guide RNA called pegRNA and a reverse transcriptase. During this process Cas9 cuts a single strand without causing double strand breaks as seen with past Cas9 enzymes. Cas9 knows where to cut because pegRNA indicates the site AND carries the RNA sequence encoding the DNA sequence to be placed in that site—with the help of the reverse transcriptase. Further testing is indeed required to determine how effective prime editing is. Nonetheless, Anzalone and his team claim in their Nature publication that this technology “could correct up to 89% of known genetic variants associated with human diseases,” giving hope to millions around the world.
Unchallenged Global Warming Will Cause the Extinction of the Emperor Penguin
Emperor penguins are magnificent animals and sadly will go extinct unless we address climate change. As many studies have shown, global warming is a dangerous phenomenon that will threaten many species. Scientists at the Woods Hole Oceanographic Institution have found, assuming global warming as allowed to continue unchallenged, the emperor penguin population in Antarctica will decline by 81%, leading to their eventual extinction. However, the authors do point out that fighting climate change by accomplishing the goals of the Paris Agreement would prevent the catastrophic extinction of the emperor penguin.
Emperor Penguin
The Devastating Effects of Measles—Underscoring the Need to Vaccinate
Measles is a horrifying disease with devastating repercussions including death. Fortunately, measles can be prevented through vaccination. However, the number of unvaccinated individuals has caused outbreaks in different parts of the world putting this disease and the importance of vaccination in the forefront of global health discussions. Recently, a study published in Science presented further data that supports the need for a measles vaccination. Michael J. Mina and his colleagues found measles actually depletes 11-73% of antibodies in individuals. That is, preexisting antibodies that fight other infections are depleted once an unvaccinated person acquires measles. Thus, this disease can render an individual defenseless against many other diseases. They also observed that the measles vaccine does NOT have the same result. The measles vaccines do not cause a decrease in antibodies and “do not increase susceptibility to subsequent infections.” In other words, the measles vaccine works.
Measles Molecular Rendering
Impossible burger
The company Impossible Foods has created a burger made from bioengineered yeast and soy that has all the characteristics of the real thing without cholesterol. It is called “the impossible burger.” Others have attempted to generate healthier and sustainable alternatives to meat and ground beef, the black bean burger, for example. However, the taste and feel of these veggie burgers lack the features of real burger meat, specifically, the metallic taste and color that heme gives meat.
Heme is an iron molecule that is carried in a protein called hemoglobin, which is also found in soy plants, with the name leghemoglobin (legHB). A few years ago, scientists engineered the yeast Pichia pastoris to express legHB allowing the production of large amounts of heme and facilitating the making of the “Impossible burger.” Achieving the likeness to real meat also required that scientists use additional methods, such as gas chromatography mass spectrometry. In the end, they created a ground beef-like patty that began a frenzy when it became available on the menus of various fast food chain restaurants earlier this year. This year, Impossible Foods released a new and improved gluten-free version, and the raw version started being sold in stores in early September giving customers the ability to go their grocery store and grill their impossible burgers right at home.
Nobel Prize awarded to James Peebles, Michel Mayor and Didier Queloz
While this event is not a discovery of 2019, it does represent great contributions to science in our time. This year the Nobel Prize in physics was awarded to James Peebles, Michel Mayor and Didier Queloz. James Peebles contributed greatly to understanding of the evolution of the universe after the Big Bang. Michel Mayor and Didier Queloz discovered 51 Pegasi b, the first exoplanet—a planet outside of our solar system.
First ever image of a black hole
Thanks to a series of telescopes called Event Horizon Telescope we now know what a black hole looks like. We have known what black holes are—regions in space that have very strong gravity where nothing escapes. However, it wasn’t until this year that we were able to observe the anatomy of a supermassive (the largest black holes) black hole, specifically one in the center of supergiant elliptical galaxy Messier 87, which is 54 million light years away from earth.
Rendering of Black Hole Image
References
Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Baczko, A. K.,… Ziurys, L. (2019). First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole. The Astrophysical Journal Letters, 875:L1 (17pp).
Anzalone, A. V., Randolph, P. B., Davis, J. R., Sousa, A. A., Koblan, L. W., Levy, J. M., …Liu, D. R. (2019). Search-and-replace genome editing without double-strand breaks or donor DNA. Nature.
Cohen, J. (2019). Prime editing promises to be a cut above CRISPR. Science, 366(6464), 406–406.
Fraser, R. Z., Shitut, M., Agrawal, P., Mendes, O., & Klapholz, S. (2017). Safety evaluation of soy leghemoglobin protein preparation derived from Pichia pastoris, intended for use as a flavor catalyst in plant-based meat. Int. J. Toxicol., 37(3), 241-262.
Harvati, K., Röding, C., Bosman, A. M., Karakostis, F. A., Grün, R., Stringer, C., … Kouloukoussa, M. (2019). Apidima cave fossils provide earliest evidence of Homo sapiens in Eurasia. Nature, 571, 500-504.
Hütter. G., Nowak, D., Mossner, M., Ganepola, S., Müssig, A., Allers, K., … Thiel, E. (2009). Long-term control of HIV by CCR5 delta32/delta32 stem-cell transplantation. N. Enlg. J. Med., 360(7), 692-698
Jenouvrier, S., Iles, D., Labrousse, S., Landrum, L., Garnier, J., Caswell, H., Barbraud, C., Weimerskirch, H., LaRue, M., Ji, R. & Holland, M. The Paris Agreement objectives will likely halt future declines of emperor penguins. Global Change Biology.
Kulp, S. A., & Strauss, B. H. (2019). New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding. Nature Communications, 10(1).
Ledford, H. (2009). Stem-cell transplant wipes out HIV. Nature.
Meet the Impossible Burger. (n.d.). Retrieved November 21, 2019, from https://impossiblefoods.com/burger/.
The Nobel Prize in Physics 2019. (n.d.). Retrieved November 20, 2019,
Vrselja, Z., Daniele, S. G., Silbereis, J., Talpo, F., Morozov, Y. M., Sousa, A. M. M., … Sestan, N. (2019). Restoration of brain circulation and cellular functions hours post-mortem. Nature, 568, 336-343.
Warren, M. (2019). Second patient free of HIV after stem-cell therapy. Nature. doi: 10.1038/d41586-019-00798-3.