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Comment by Dr. Krishna Kumari Challa on April 22, 2015 at 6:06am

How the skin fusing works in wound healing ... an interesting observation by scientists

Scientists from the Goethe University Frankfurt, the European Molecular Biology Laboratory Heidelberg and the University of Zurich explain skin fusion at a molecular level and pinpoint the specific molecules that do the job in their latest publication in the journal Nature Cell Biology.

As a first step, as the scientists discovered, cells find their opposing partner by "sniffing" each other out. As a next step, they develop adherens junctions which act like a molecular Velcro. This way they become strongly attached to their opposing partner cell. The biggest revelation of this study was that small tubes in the cell, called microtubules, attach to this molecular Velcro and then deploy a self-catastrophe, which results in the skin being pulled towards the opening, as if one pulls a blanket over.

Damian Brunner who led the team at the University of Zurich has performed many genetic manipulations to identify the correct components. The scientists were astonished to find that microtubules involved in cell-division are the primary scaffold used for zipping, indicating a mechanism conserved during evolution.

"What was also amazing was the tremendous plasticity of the membranes in this process which managed to close the skin opening in a very short space of time. When five to ten cells have found their respective neighbors, the skin already appears normal", says Achilleas Frangakis from the Goethe University Frankfurt, who led the study.

The scientists hope that their results will open new avenues into the understanding of epithelial plasticity and wound healing.

"Quantitative analysis of cytoskeletal reorganization during epithelial tissue sealing by large-volume electron tomography"

http://www.nature.com/ncb/journal/vaop/ncurrent/full/ncb3159.html

Comment by Dr. Krishna Kumari Challa on April 16, 2015 at 1:19pm

Sperm from men with children with early signs of autism spectrum disorders (ASD) have distinct DNA methylation patterns which could be contributory to autism. This is the main finding of a new study from researchers in John Hopkins published online in the International Journal of Epidemiology on April 15th.
The authors concluded that the methylation results from paternal sperm, together with the post-mortem brain evidence showing directionally consistent, potentially related epigenetic mechanisms, suggest that epigenetic methylation differences in paternal sperm may be contributory to risk of autism spectrum disorders in children. As this was a relatively small study, the team plans to extend the study to more families to confirm its and to examine occupations and environmental exposures of the fathers in the study. Currently, there is no genetic or epigenetic test available to assess autism risk. Studies such as this may help to address this problem for the future.
http://ije.oxfordjournals.org/content/early/2015/04/14/ije.dyv028.s...

Comment by Dr. Krishna Kumari Challa on April 15, 2015 at 11:28am

Physicists are able to make cylindrical objects completely invisible in the microwave range, without using any metamaterial coating layers, ushering in new era of electromagnetic wave scattering.

The scientists from ITMO University, Ioffe Institute and Australian National University achieved the unique result based on light scattering from a glass cylinder filled with water, representing a two-dimensional analog of a classical scattering from a homogenous sphere (Mie scattering).

Using ordinary water whose refractive index can be regulated by reducing temperature, they applied two scattering methods —
resonant and non-resonant scattering. Resonant scattering is related to localization of light inside the cylinder and in non-resonant it is reflected by smooth dependence on the wave frequency, they explained. And interaction between the two mechanisms is called Fano resonances.
In their xperiment, the researchers discovered that at certain frequencies waves scattered via both mechanisms in opposite
phases and are mutually destroyed, making the object invisible. By the cancellation of scattering, they were able to develop a new technique to switch from visibility to invisibility at the same freequency of 1.9GHz by reducing the temperature of water in a cylinder from 90°C to 50°C.

“Our theoretical calculations were successfully tested in microwave experiments. What matters is that the invisibility idea we implemented in our work can be applied to other electromagnetic wave ranges, including to the visible range,” said Mikhail Rybin, lead author of the paper at the Metamaterials Laboratory in ITMO University.

The discovery can help develop nanoantennas, wherein invisible rods could be used as supports for a miniature antenna complex connecting two optical chips. Since the new discovery of invisibility phenomenon in a homogenous object and not an object covered with additional coating layers makes it deviate from conventional ideas of invisibility.

Nevertheless, coating layers based on metamaterials are extremely hard to fabricate and are not compatible with many other invisibility ideas. The new method based on scattering processes leaves behind the existing mechanisms both in simplicity and cost-effectiveness, they said.

Wearing an invisibility cloak is every fantasy-lovers dream. It has caught the attention of physicists for centuries and even films like ‘Mr India’ with an invisibility watch had an exciting viewership, while epics are aplenty about the examples of ancient sages going invisible or making objects invisible.
- http://www.microfinancemonitor.com/2015/04/14/physicists-create-hom...

Comment by Dr. Krishna Kumari Challa on April 15, 2015 at 11:09am

Researchers have found that inhibiting DNA recombination at the telomeres can promote longevity, at least in yeast. Their results have been published in PLOS Genetics. Homologous recombination is a process used to repair double stranded breaks in DNA, thereby preventing genome instability which is believed to cause aging. The shortening of telomeres, the physical ends of eukaryotic linear chromosomes, has also implicated in aging. However, due to the resemblance of telomeres to DNA double strand breaks (DSBs), homologous recombination can not be eliminated from telomeres. Professor Zhou Jinqiu and his group at the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, has now identified a telomere recombination regulator, the yeast KEOPS subunit Cgi121, as a novel longevity regulator. They showed that inactivation of Cgi121 inhibited telomere recombination and significantly extended the lifespan of yeast.

''Inhibition of Telomere Recombination by Inactivation of KEOPS Subunit Cgi121 Promotes Cell Longevity''
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pg...

Comment by Dr. Krishna Kumari Challa on April 14, 2015 at 7:17am

Citizen science projects let you make the amazing discoveries
http://www.theweathernetwork.com/news/articles/for-science-citizen-...
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Comment by Dr. Krishna Kumari Challa on April 14, 2015 at 6:49am

Preliminary studies by neuro-scientists tell an interesting story:

Birth control pills taken by women effects brain structure and activity...

 Birth control pills have structural effects on regions of the brain that govern higher-order cognitive activities, suggesting that a woman on birth control pills may literally not be herself -- or is herself, on steroids.

Neuroscientists from the University of California, Los Angeles in the US took brain scans of 90 women who were either currently using the pill or not, and found that two key brain regions were thinner in pill users - the lateral orbitofrontal cortex and the posterior cingulate cortex.

New research suggests that the synthetic steroids delivered by the female contraceptive pill can shrink certain regions of the female brain and could also be altering their function.

Neuroscientists from the University of California, Los Angeles in the US took brain scans of 90 women who were either currently using the pill or not, and found that two key brain regions were thinner in pill users - the lateral orbitofrontal cortex and the posterior cingulate cortex.

These two regions are involved in emotion regulation, decision-making and reward response, and the researchers believe that their findings could help explain why some women become anxious or depressed when taking the contraceptive pill. It's possible that this change in the lateral orbitofrontal cortex may be related to the emotional changes that some women experience when using birth control pills.

Scientists have previously shown that the pill can affect to whom a woman is attracted, and can halve the size of their ovaries. And in 2010, a team from Austria also found that the contraceptive pill could change the shape of the brain regions associated with learning, memory and emotion regulation. But their research suggested that it thickened those regions, rather than thinning them, a result that this new study contradicts.

However, it's important to note that the research is in the very early stages, and didn't look into whether going on or off the pill changed brain shape within the same women. The researchers also haven't studied whether the effects are permanent or temporary.

:"Oral contraceptive pill use is associated with localized decreases in cortical thickness":

http://onlinelibrary.wiley.com/doi/10.1002/hbm.22797/abstract?campa...

Comment by Dr. Krishna Kumari Challa on April 11, 2015 at 9:31am

Why do people do what they do? It is the brain chemistry that decides!
The function of two chemical signals critical to human behavior: Dopamine–responsible for reward and risk-taking–and CREB–needed for learning.
We can now predict future animal behaviors based on past sensory experience, independent of the influence of genetic factors using this information.
Dumping dopamine onto a brain–human or otherwise–makes one more willing to take risks.
Stimulated by large varieties in its environment, dopamine surges in the organism's system and activates four other neurons in the learning circuit, giving them a greater response range. This prompts the it to search more actively in a wider area (risk-taking) until it hits a more consistent environment. The amount of dopamine in its system serves as its memory of the past experience: about 30 minutes or so and it forgets information gathered in the time before that.
While it’s been known that the presence of dopamine is tied to risk-taking behavior, how exactly dopamine does this hasn’t been well understood. With a new work, scientists now have a fundamental model of how dopamine signaling leads the organism to take more risks and explore new environments.
The connection between dopamine and risk is conserved across animals and is already known, but the new work showed mechanistically how it works. Interestingly, the scientists found that the high-threshold neurons also lead to increased signaling from a protein called CREB, known in humans and other animals to be essential to learning and retaining new memories. The researchers showed that not only are the presence of CREB important to learning, but the amount of CREB protein determines how quickly an animal learns. This surprising connection could lead to new avenues of research for brain enhancements.
When the protein CREB was present in larger amounts, the team found that the organisms took far less time to learn.
http://www.sciencedirect.com/science/article/pii/S0896627315002500
Neural Mechanisms for Evaluating Environmental Variability in Caenorhabditis elegans
C. elegans learn variability in their food environment and modify future behavior
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The authors describe the minimal circuit that evaluates environmental variability
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Dopamine levels store information about variability to regulate behavior
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The amount of CREB determines the rate of learning variability

Comment by Dr. Krishna Kumari Challa on April 11, 2015 at 7:29am

How neuro-scientists think they can do the head transplants...

The procedure starts with cooling both the body and head right down so the cells won’t die when deprived of oxgyen through the process. Next, the neck is severed and all the crucial blood vessels are hooked up to tubes while the spinal cord on both the head and the body are severed.

"The recipient's head is then moved onto the donor body and the two ends of the spinal cord – which resemble two densely packed bundles of spaghetti – are fused together,” says Thomson. "To achieve this, scientists intend to flush the area with a chemical called polyethylene glycol, and follow up with several hours of injections of the same stuff. Just like hot water makes dry spaghetti stick together, polyethylene glycol encourages the fat in cell membranes to mesh.”

Canavero told Thomson the final step would be to stitch up the muscles and blood supply, and to induce a three- or four-hour coma to let the body heal itself while embedded electrodes stimulate the spinal cord to strengthen the new nerve connections.

The recipient won’t be able to get up and walk around soon after the surgery because the damage to the spinal cord would take about 12 months to heal fully. The recipient would retain their old voice though.
But... we don’t even know if the plan to use polyethylene glycol to fuse the spinal cords is even going to work, in which case scientists will be forced to use one of their other options. There is no evidence that the connectivity of cord and brain would lead to useful sentient or motor function following head transplantation.
And... how do you get the body to stop automatically rejecting the head?

There’s no telling what the transplant - and all the new connections and foreign chemicals that the head and brain will have to suddenly deal with - will do to person’s psyche, could result in a hitherto never experienced level and quality of insanity. Scary!

- The New Scientist

Comment by Dr. Krishna Kumari Challa on April 8, 2015 at 9:05am

This topic always fascinates me... understanding the death dance...another step towards it...
Asphyxia-activated corticocardiac signaling accelerates onset of cardiac arrest
http://www.pnas.org/content/early/2015/04/02/1423936112
Death Brain Signaling Accelerates Demise of the Heart...
What happens in the moments just before death is widely believed to be a slowdown of the body’s systems as the heart stops beating and blood flow ends. For the study, performed in rats, researchers simultaneously examined the heart and brain during experimental asphyxiation and documented an immediate release of more than a dozen neurochemicals, along with an activation of brain-heart connectivity. This new laboratory study by the University of Michigan Medical School reveals a storm of brain activity that erupts as the heart deteriorates and plays a surprising destabilizing role in heart function.

This near-death brain signaling may be targeted to help cardiac arrest patients survive.
Despite the loss of consciousness and absence of signs of life, internally the brain exhibits sustained, organized activity and increased communication with the heart, which one may guess is an effort to save the heart.
However the brain signaling at near-death may, in fact, accelerate cardiac demise, according to the study published in this week’s PNAS Early Edition.

Researchers with backgrounds in engineering, neuroscience, physiology, cardiology, chemistry, and pharmacology looked at the mechanism by which the heart of a healthy person ceases to function within just a few minutes without oxygen.

While the animal study examined asphyxia-induced cardiac arrest, sudden cardiac death can also follow fatal cardiac arrhythmias, ischemic stroke, traumatic brain injury, brain hemorrhage and epilepsy.

Following a steep fall of the heart rate, brain signals strongly synchronized with the heart rhythm, as visualized beat-by-beat using a new technology developed in the Borjigin laboratory called electrocardiomatrix.

According to the study, blocking the brain’s outflow significantly delayed ventricular fibrillation, in which the lower chambers of the heart quiver and the heart cannot pump any blood. It’s the most serious cardiac rhythm disturbance.

The study suggests that a pharmacological blockade of the brain’s electrical connections to the heart during cardiac arrest may improve the chances of survival in cardiac arrest patients.
This new study provides a neurochemical foundation for the surge in brain activity and a brain-heart connectivity that may be targeted to lengthen detectable brain activity.

Comment by Dr. Krishna Kumari Challa on April 8, 2015 at 8:47am

One can develop allergies a few weeks after receiving blood transfusions
'Peanut and fish allergy due to platelet transfusion in a child'
http://www.cmaj.ca/content/early/2015/04/07/cmaj.141407
Although this is rare, an eight year old boy developed allergy toward salmon and peanut butter after the blood transfusion because the donor had these allergies. However, these allergies are short lived and dissipate after some months because the recipients themselves don't produce the allergen antibodies.
The principle behind it is Clinicians purposefully transfer antibodies to give patients protection against infections, so it is not surprising that other antibodies could be transferred and cause ripple effects. Large amounts of immunoglobulin-E (IgE) antibodies remain in blood products even after storage of more than a month. Typically, fresh frozen plasma will contain the largest amount of the antibodies, followed by platelets and then red cells because all three blood components contain plasma, which can contain antibodies.
Multiple events must come together for a patient to have this rare allergic reaction. First, the blood donor must have high levels of IgE antibodies—those that react against allergens. Second, a substantial amount of blood product must be given to the patient. Then, in order to detect the new allergy, the patient would have to be exposed to the specific allergen the antibodies would react against within a few months of receiving the transfusion. That window is tight, because passively acquired antibodies will naturally fade after a few months and the transient allergy will disappear. IgE is estimated to have a half-life of just a few hours or days, but once it enters the body and binds to cells, it can remain detectable for weeks or months and cause allergic reactions

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