Article: The Interstitium, the Largest Organ We Never Knew We Had [The Daily Beast]

“What is an organ? Anatomy textbooks are rather fuzzy about what defines an “organ,” requiring one to have primary tissue—parenchyma—and “sporadic” tissue, called stroma, which can be nerves, vessels, and other connective tissue. Organs are the necessary building blocks of organisms (hence, the name), and can be gigantic or microscopic. So long as cells clump together to form tissues, and these tissues organize themselves into organs that perform specific functions in the survival of an organism, that mass of tissues and cells can be called an organ.

“Theise, Carr-Locke, and Benias weren’t sure what to call this space with its collagen bundles and fluid. The fluid itself appeared rich in proteins typical of lymphatics and serum, but the space was neither lymphatic nor vascular (meaning that it contained neither veins nor arteries), so what could it be?

“That’s when it dawned on them that what they’d stumbled upon was actually talked about in medical textbooks, but that they were the first to actually define it.

“This thing they were looking at, struggling to understand with its bizarre structure and rule-breaking form, was the interstitium, a space vaguely described in textbooks as where “extracellular fluid” is found, the fluid that isn’t contained within cells. What doctors had defined as “dense connective tissue” wasn’t dense connective tissue at all. In fact, they were all fluid-filled structures that only appeared to be densely compacted when tissues were made into slides, the fluid draining away, the collagen lattice collapsing onto itself.

“They had a theory—that the space was the interstitium—and a way to prove it. They were on to something.”

Read Tanya Basu’s full article at Daily Beast: The Interstitium, the Largest Organ We Never Knew We Had

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Article: University of Barcelona Researchers Describe a New Anatomic Structure in the Ankle [Universitat de Barcelona]

“Describing that part of the anterior talofibular ligament is an intra-articular structure could have implications in the evolution and treatment of this kind of injuries. “These findings suggest the behaviour after an injury will be similar to the other intra-articular ligaments, such as the twill, which are not able to cicatrize, and this makes the joint to remain unstable and in many cases it requires a surgical operation”, says Miquel Dalmau-Pastor.

“These results would explain why many sprains cause pain after the patient follows the treatment the doctor suggests. “Since the intra-articular ligament does not cicatrize, the instability of the joint produces pain so these patients are likely to suffer from another sprain and develop other injuries in the ankle”, highlights Francesc Malagelada. 

“Apart from the anatomic observation in the dissections carried out at the University of Barcelona, the researchers studied the behaviour of ligaments. “The superior fascicle in the anterior talofibular ligament, apart from being intra-articular, is not an isometric structure –that is, it relaxes when the foot is on a dorsal flexion, and it tenses when it is on a plantar flexion. However, the inferior fascicle, the arciform fibers and the calcaneofibular ligament, the described ligament complex, are extra-articular structures and are isometric, so that they are always taut”, concludes Maria Cristina Manzanares.”

Read the full article from Universitat de Barcelona: University of Barcelona Researchers Describe a New Anatomic Structure in the Ankle

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Article: Spinal Cord is ‘Smarter’ Than Previously Thought [Medical Xpress]

“This research has shown that a least one important function is being done at the level of the spinal cord and it opens up a whole new area of investigation to say, ‘what else is done at the spinal level and what else have we potentially missed in this domain?'” said the study’s senior and supervising researcher Andrew Pruszynski, Ph.D., assistant professor at Western’s Schulich School of Medicine & Dentistry and Canada Research Chair in Sensorimotor Neuroscience.

“The study, “Spinal stretch reflexes support efficient hand control,” will be published online in the high impact journal Nature Neuroscience.

“This kind of hand control requires sensory inputs from multiple joints—mainly the elbow and the wrist—and these inputs was previously thought to be processed and converted into motor commands by the brain’s cerebral cortex.

“Using specialized robotic technology, a three degree of freedom exoskeleton at Western’s Brain and Mind Institute, subjects were asked to maintain their hand in a target position and then the robot bumped it away from the target by simultaneously flexing or extending the wrist and elbow. The researchers measured the time that it took for the muscles in the elbow and wrist to respond to the bump from the robot and whether these responses helped bring the hand back to the initial target.

“By measuring the latency, or ‘lag’, in the response, they were able to determine whether the processing was happening in the brain or the spinal cord.

“We found that these responses happen so quickly that the only place that they could be generated from is the spinal circuits themselves,” said the study’s lead researcher Jeff Weiler, Ph.D., a post-doctoral fellow at Schulich Medicine & Dentistry. “What we see is that these spinal circuits don’t really care about what’s happening at the individual joints, they care about where the hand is in the external world and generate a response that tries to put the hand back to where it came from.”

Read the full summary from University of Western Ontario at Medical Xpress: Spinal Cord is ‘Smarter’ Than Previously Thought

Their citation: Spinal stretch reflexes support efficient hand control , Nature Neuroscience (2019). DOI: 10.1038/s41593-019-0336-0 ,

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Article: A Totally New Type of Blood Vessel Has Been Discovered Hidden in Human Bones [Nexus Newsfeed]

“These tiny canals, called ‘trans-cortical vessels’ (TCVs), may be new to science, but they help explain how emergency drug infusions first pioneered on the battlefield were able to rapidly revive injured soldiers.

“In such emergencies, medics don’t always have the time or ability to find or access veins, resorting to injecting drugs directly into bone marrow.

“Despite accumulating evidence for the presence of a complex blood supply in bone, the molecular mechanisms and anatomy underlying these rapid shifts of cells and fluid from bone marrow to the circulation have remained elusive,” a commentary on the new research explains.

“Now, the basis of that mechanism is laid bare, having first been spotted by accident several years ago. Gunzer was studying fluorescent-dyed blood cells in mice, and observed them under the microscope appearing to pass through what should have been solid bone.

“Unable to discover anything in medical literature that could explain the phenomenon, he devised a new research project to explore what was going on.

“In the new study, Gunzer’s team used a chemical called ethyl cinnamate on mice tibiae (leg bones) to ‘clear’ the bones, making them transparent.

“Then, using a combination of light-sheet fluorescence microscopy (LSFM) and X-ray microscopy, they were able to detect for the first time several hundreds of these tiny TCVs passing through the cortical layer of the leg bones.”

Read Peter Dockrill’s full article on Nexus Newsfeed: A Totally New Type of Blood Vessel Has Been Discovered Hidden in Human Bones

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Article: Everywhere in Your Body is Tissue Called Fascia. Scientists are Unlocking Its Secrets [Washington Post]

“Although some people who are kneaded, stretched, or cracked may have a vague notion that fascia exists, they probably don’t know much about their fascia — or understand why it even matters.

“Some in the scientific and medical communities think the same way.

“They cannot agree on what fascia is. They don’t know what fascia does. They may not even know it when they see it. (One scientist, when asked about fascia, had to look it up to try to define it. And a scientific group, the Fascia Nomenclature Committee, has devoted itself to resolving this language confusion.)

“But this is what they suspect: As the only tissue that modifies its consistency when under stress (it’s your body’s shape-shifter, of sorts), fascia is a part of the body that inspires equal parts confusion and optimism in research circles.

“It’s everywhere in the body, so it could affect just about everything. That leaves researchers wrestling with an intriguing dilemma: If fascia is everywhere, then how do you isolate its impact on the body?

“Early research suggests it may have relevance in areas one wouldn’t normally think of fascia playing a role, such as digestive conditions and cancer.

“Fascia is what holds us together. There are very few diseases that don’t have a fascia component,” said Frederick Grinnell, a professor of cell biology at the UT Southwestern Medical School.”

Read Rachel Damiani and Ted Spiker’s full article at the Washington Post: Everywhere in Your Body is Tissue Called Fascia. Scientists are Unlocking Its Secrets.

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