By discovering a new mechanism that allows blood to enter the brain immediately after a stroke, researchers at UC Irvine and the Salk Institute have opened the door to new therapies that may limit or prevent stroke-induced brain damage.
A complex and devastating neurological condition, stroke is the fourth-leading cause of death and primary reason for disability in the U.S. The blood-brain barrier is severely damaged in a stroke and lets blood-borne material into the brain, causing the permanent deficits in movement and cognition seen in stroke patients.
Dritan Agalliu, assistant professor of developmental & cell biology at UC Irvine, and Axel Nimmerjahn of the Salk Institute for Biological Studies developed a novel transgenic mouse strain in which they use a fluorescent tag to see the tight, barrier-forming junctions between the cells that make up blood vessels in the central nervous system. This allows them to perceive dynamic changes in the barrier during and after strokes in living animals.
While observing that barrier function is rapidly impaired after a stroke (within six hours), they unexpectedly found that this early barrier failure is not due to the breakdown of tight junctions between blood vessel cells, as had previously been suspected. In fact, junction deterioration did not occur until two days after the event.
Instead, the scientists reported dramatic increases in carrier proteins called serum albumin flowing directly into brain tissue. These proteins travel through the cells composing blood vessels – endothelial cells – via a specialized transport system that normally operates only in non-brain vessels or immature vessels within the central nervous system. The researchers’ work indicates that this transport system underlies the initial failure of the barrier, permitting entry of blood material into the brain immediately after a stroke (within six hours).
“These findings suggest new therapeutic directions aimed at regulating flow through endothelial cells in the barrier after a stroke occurs,” Agalliu said, “and any such therapies have the potential to reduce or prevent stroke-induced damage in the brain.”
His team is currently using genetic techniques to block degradation of the tight junctions between endothelial cells in mice and examining the effect on stroke progression. Early post-stroke control of this specialized transport system identified by the Agalliu and Nimmerjahn labs may spur the discovery of imaging methods or biomarkers in humans to detect strokes as early as possible and thereby minimize damage.
In a cloning first, scientists create stem cells from adults
Scientists have moved a step closer to the goal of creating stem cells perfectly matched to a patient’s DNA in order to treat diseases, they announced on Thursday, creating patient-specific cell lines out of the skin cells of two adult men.
The advance, described online in the journal Cell Stem Cell, is the first time researchers have achieved “therapeutic cloning” of adults. Technically called somatic-cell nuclear transfer, therapeutic cloning means producing embryonic cells genetically identical to a donor, usually for the purpose of using those cells to treat disease.
Differences in brain connectivity may help explain the social impairments common in those who have autism spectrum disorders, new research suggests.
The small study compared the brains of 25 teens with an autism spectrum disorder to those of 25 typically developing teens, all aged 11 to 18….
Hundreds of thousands of web and email servers worldwide have a software flaw that lets attackers steal the cryptographic keys used to secure online commerce and web connections, experts say.
They could also leak personal information to hackers when people carry out searches or log into email.
Happy Hump Day, y’all.
Not too surprising but interesting to see which social networks are mostly mobile.
Wine Box Version 2 (2014)
second cycle sustainability The life cycle of of materials requires that re-use be built into the design of products if sustainability is truly to be a consideration as the human footprint on the environment is paramount to all superficial constructions deemed worthy of LEED credit.
Neurosurgeons successfully implant 3D printed skull
A 22-year-old woman from the Netherlands who suffers from a chronic bone disorder — which has increased the thickness of her skull from 1.5cm to 5cm, causing reduced eyesight and severe headaches — has had the top section of her skull removed and replaced with a 3D printed implant.
The operation was performed by a team of neurosurgeons at the University Medical Centre Utrecht and the university claims this is this first instance of a successful 3D printed cranium that has not been rejected by the patient.
The operation, which took 23 hours, was led by Dr Bon Verweij. The patient’s skull was so thick, that had the operation not been performed, serious brain damage or death may have occurred in the near future.