Top 5 Science Stories This Summer

NISREEN SHIBAN

Recent studies show that certain cells in the pancreas are capable of reverting to embryonic-like progenitor cells that may be related to illnesses like diabetes and pancreatic cancer.

Nisreen Shiban, Featured Image

5. Growing Liver in the Lab Generating organs from stem cells may address the critical shortage of donor organs needed for treating organ failure. Despite reports of operative cell differentiation, none have described generation of a functional vascularized liver. In a study reported in the journal Nature, however, Takanori Takebe and his team of the Yokohama City University Graduate School of Medicine in Japan grew tissue resembling the human liver in a lab mouse. By creating reprogrammable human induced pluripotent stem cells (iPSC) and mixing them with other cells, they observed the cells self-organizing into “liver buds,” the precursor clusters that develop into an adult liver. They were transported into a mouse brain and observed in vitro. The liver performed human-specific functions like producing proteins and absorbing specific drugs demonstrated in urine and serum samples. The liver buds and host endothelial cells were observed through intravital imaging. The study holds promise for a different approach to regenerative medicine.

Further reading: “Vascularized and functional human liver from an iPSC-derived organ bud transplant” Takebe T., Sekine K., Enomura M.,Taniguchi H., et al., Nature, 499, 481–484 (25 July 2013)

4. The Manchurian Candidate? Planting False Memories in the Brain
Scientists have attempted to generate a false memory by associating external stimuli with previously formed memory. In order to understand the role of brain activity in driving cognition, neuroscientists aim to identify the brain regions involved in producing memories.  Disturbing brain activity may provide insight on how cognitive processes are affected.  Scientists at the MIT Center for Neural Circuit Genetics and Howard Hughes Medical Institute have used fear conditioning in mice to identify a subpopulation of cells in the dentate gyrus of the hippocampus and stimulated them to activate behavioral recall of that painful memory: receiving foot shocks. They conjecture that some false memories in humans are due to internal retrieval of previous memories and their association with external stimuli.

Further reading: “Creating a False Memory in the Hippocampus” Ramirez, S, Liu, X., Lin, P.,  Susumu Tonegawa, S., Science Magazine, 26 July 2013: Vol. 341 no. 6144 pp. 387-391

3. The Plastic Pancreas: Dedifferentiating Rather Than Dying
Recent studies show that certain cells in the pancreas are capable of reverting to embryonic-like progenitor cells that may be related to illnesses like diabetes and pancreatic cancer. Since these cells can revert back to their progenitor origins rather than die off, it might be possible to reverse this process and treat the illnesses. Previous studies discovered how the progenitor cells give rise to duct and endocrine cells that differentiate only into acinar cells, the most abundant cells in the pancreas. Recent findings in the pancreatic cancer field have suggested that acinar cells are the most likely origins of pancreatic ductal adenocarcinoma, the most common of pancreatic cancers, linking cancer to abnormal tissue regeneration. Beta cell failure in type 2 diabetes might involve cell dedifferentiation rather than cell death. The recent findings suggest a hypothetical unifying view of the link between adult pancreas plasticity and disease.

Further reading: “The Plastic Pancreas,” Ziv O., Glaser, B., Dor, Y., Developmental Cell, Volume 26, Issue 1, 3-7, 15 July 2013

2. Who Said Mountain Air Was Good For You?
Scientists from the Centre for Altitude, Space and Extreme Environment Medicine (CASE) at University College London explore the ways in which the human body adapts to high altitudes. They found that the therapeutic direction in hospital patients should be to help the body reduce oxygen consumption rather than drive delivery as was previously thought. The body quickly reacts to lower levels of oxygen by increasing blood pressure and heart rate leading to illnesses as fluids leak from the cells into cavities in the lung and brain. The body also increases red blood cells and hemoglobin production, which increases the amount of oxygen tissues receive. In higher altitudes, however, increasing hemoglobin would thicken the blood making it more susceptible to strokes and other complications. The people living in high altitudes on a regular basis have found ways to deal with this by regulating hemoglobin production and functioning with less oxygen.

“Out of thin air.”, Douglas, Ed, New Scientist, June 15, 2013, Vol. 218, Issue 2921

1. Does Not Compute:  Approaching the Edge of the Internet
The capacity of the world’s networking infrastructure may soon come to an end due to the exponential growth of information. Markus Hofmann, head of Bell Labs Research, provides answers about the necessary advances that would boost the capacity of the network. The telecommunication infrastructure is approaching the fixed nonlinear Shannon limit, the phenomenon that describes the limit to the information transmitted over certain communications channels. In order to continue the needed growth, we need to lay more optical fiber and increase the number of optical amplifiers, transmitters and receivers. The infrastructure must look at data as more than bits and bytes but rather as information relevant to individual people. It should become aware of the information it carries in order to prioritize its delivery. One way is by peeking into the information or tagging the data and giving the network instructions on how to handle it. A new model that looks at information before it reaches the network is needed to limit the raw data sent to the processing centers.

Further reading: “Edge of the Internet,” Greenemeier, L. Scientific America, Vol 308, Issue 6.

Nisreen Shiban is a Brevia staff writer. She can be reached at nisreenshiban01@college.harvard.edu.