Gradual Starvation Of Brain Could Trigger Alzheimer’s
A gradual loss of blood flow to the brain over years or decades could be a major trigger for Alzheimer’s disease, according to a study. Up till now, the cause for this disease has remained a mystery, even if the mechanism causing the damage is well understood.
The new research shows that an insufficient supply of sugar glucose, transported by blood, sets off a biochemical chain reaction resulting in the accumulation of the neuron-attacking proteins that cause Alzheimer’s.
“This findings is significant because it suggests that improving blood flow to the brain might be an effective therapeutic approach for prevention or treatment of Alzheimer’s,” said Robert Vassar, a professor at North Western University’s Feinberg School of Medicine, and lead author of this study.
“Exercising, reducing cholesterol intake and managing hypertension are the measures that could provide added protection”, he said. “For persons who already show symptoms of constricted arteries, taking vasodilators (drugs that boost blood flow) could help deliver nourishing oxygen and glucose to the brain,” he added.
Drawing from experiments with humans and mice, Vassar and colleagues showed that reduced blood flow alters a protein called elF2alpha. In its changed form, elF2alpha increases the output of the enzyme that spurs production of the fiber-like knots of amyloidal beta protein that form outside neurons and disrupt their ability to send messages.
The finding published in the journal Neuron could lead to drugs designed to block the elF2alpha production that begins the formation of the protein clumps, also known as amyloid plaques, Vassar added.
Alzheimer’s disease is incurable and is the most common form of dementia among older people. It affects the regions of the brain involving thought, memory and language.
Source: TOI
Blind, Yet Seeing: Brain Has Subconscious Visual Sense
The man, a doctor left blind by two successive strokes, refused to take part in the experiment. He could not see anything, he said, and had no interest in navigating an obstacle course a cluttered hallway for the benefit of science. Why bother?
When he finally tried it, though, something remarkable happened. He zigzagged down the hall, sidestepping a garbage can, a tripod, a stack of paper and several boxes as if he could see everything clearly.
“You just had to see it to believe it,” said Beatrice de Gelder, a neuroscientist at Harvard and Tilburg University in the Netherlands, who with an international team of brain researcher reported on the patient in journal Current Biology.
The study, which included extensive brain imaging, is the most dramatic demonstration to date of so-called blindsight, the native ability to sense things using the brain’s primitive, subcortical and entirely subconscious visual system. Read more
Glasses That Change With Eye Power
A British scientist has designed a unique pair of glasses that can be adjusted by a wearer without any optician’s help, and one million pairs of which will soon be distributed in India.
Professor Joshua Silver is hopeful that his self adjusting glasses could enable a billion people in the developing world to receive spectacles for the first time within just over a decade.
Silver, a retired Oxford University physics professor, is even preparing to launch an ambitious scheme in India to distribute one million pairs in a year. He revealed that he came up with the idea in what he describes as a “glimpse of the obvious”, reports the Telegraph. Read more
Web Self Diagnosis May Trigger Anxiety Attacks
Playing doctor on the web often leads people to mistakenly believe that they are suffering from rare illnesses, according to a study by researchers at Microsoft.
“Web search engines have the potential to escalate medical concerns,” or “Cyberchondria”, Ryen White and Eric Horvitz wrote in the study published by the Redmond, Washington-based software company. They described cyberchondria as “unfounded increases in health anxiety based on the review of web content.” Read more
Wine Raises Cancer Risk
A large glass of wine a day increases the risk of liver and bowel cancer by a fifth, experts have warned. What’s more, the same goes for a pint of beer or a couple of spirits such as vodka or gin.
Rachel Thompson, science programme manager for World Cancer Research Fund (WCRF), warned that just two units of alcohol a day increases the risk of bowel cancer by 18 percent and the risk of liver cancer by 20 percent. Read more
Smokers at Higher Risk of Atrial Fibrillation
Offering yet another reason to never start smoking, a new study finds that both current and former smokers run an elevated risk of the heart rhythm disorder atrial fibrillation.
The condition, also known as AF, is the most common heart arrhythmia in the United States, affecting about 2 million people. During an episode of AF, abnormal electrical activity in the heart causes its upper two chambers to beat in a rapid, uncoordinated rhythm; the arrhythmia itself is not life-threatening, but over time AF can contribute to stroke or heart failure in some people.
While smoking is a well-known risk factor for heart disease, it has not been clear whether the habit boosts the risk of AF specially.
The new findings, reported in the American Heart Journal, suggest that it does even after a smoker quits. Read more
How To Measure Blood Pressure Using Mercury Sphygmomanometer
An image of Sphygmomanometer
Method
Clothing should be removed from the arm. If it cannot be removed, it is better to leave it as it is, rather than fold the clothing into tight constricting bands.
The cuff should be encircled around the arm. If the bladder of the cuff does not encircle the arm completely, the centre of the bladder should be over the brachial artery. The rubber tubes from the bladder are usually placed inferiorly at the site of the brachial artery, but it would be better to place it superiorly or posteriorly so that the antecubital fossa is easily accessible for auscultation.
The bell of the stethoscope gives better sound reproduction but a diaphragm is easier to secure with the finger of one’s hand and covers a large area.
To measure BP in the legs a thigh cuff containing a large bladder (18 x 24 cms) for adults should be wrapped around the thigh of the prone patient and the Korotkoff sounds auscultated in the popliteal fossa in the usual way.
BP in the legs is equal to that in the arms provided the bladder is adequate in size.
How To Prevent The Common Cold
- Wash yours hands often. Frequent washing of hands can destroy viruses that you have acquired from touching surfaces used by other people.
- Avoid touching your face, if you are around someone with a cold.
- Don’t smoke. Cigarette smoke can irrigate the airways and increase susceptibility to colds. Read more
Brain Implants To Move Prosthetic Limbs In Amputees
MicroBridge Services, based at Cardiff University, south Wales, is pioneering work in which tiny implants would be able to effectively channel brain-waves to prosthetic limbs. The company is a leader in micro-engineering design and manufacture and possibly the only firm in the world capable of creating the implants.
The implants are the size of a match head carrying 100 sensors made of extremely hard tungsten carbide, which conducts electricity. Only slightly thicker than a human hair, the sensors sit on the brain picking up nerve impulses and send them to prosthetic limbs. The scientists are expecting that the technology may eventually help amputees to learn to move prosthetic limbs and regain lost mobility. Read more
Scientists Find New Way To Track Cancer In Blood
Tiny sacs released from tumor cells and circulating in the blood carry genetic information about the tumor, offering a new way to track and treat the cancer, US researchers said on Sunday. “They contain a little piece of the tumor cell in the blood stream.
If you just look at these packets, you basically know what kind of mutations are in the tumor cell,” said Xandra Breakefield of Massachusetts General Hospital in Boston, whose study appears in the Journal Nature Cell Biology.
These membrane covered packets, called exosomes, represent a new way of getting information about a cancer, offering a means of choosing the best therapy, seeing how a patient responds to treatment, and possibly offering a way to deliver therapies back to the tumor, Breakefield said.
Source: TOI