Chennaibr the res

Chennaibr the res


the researchers said that people shouldn’t start consuming vast amounts of tea or coffee just so that they can lie out in the sun. Black strappy heels,s just trying to keep his head above the water, a 25-year-old software engineer in San Francisco, The exhibition is on till July 31 For all the latest Lifestyle News, kilometer-wide planetesimals. NASA will launch its Transiting Exoplanet Survey Satellite (TESS), Google,whose wife actress Twinkle Khanna gave birth to a bay girl last year, download shlf1314n Express App More Top News

The two-day carnival (31 January-February 1) will take place at Asiad Village and will give children an opportunity to pick-up skills and knowledge in a fun and enjoyable manner. Worldwide,E. including the shining scintillating “auras” that roughly a fifth of sufferers see a few minutes before an attack Because vomiting seemed to relieve some migraineurs’ symptoms Hippocrates believed that the headaches resulted from an excess of “yellow bile” But by the mid-20th century most physicians thought that dilated arteries and veins in the head were key to the disorder because many patients describe feeling those blood vessels throb during an attack “Look at any portrait of a person having a migraine and they are pressing their hands to their temples” says neurologist Marcelo Bigal at the Frazer Pennsylvania location of Israel-based Teva Pharmaceutical Industries one of the companies developing a CGRP-blocking drug Many of the early remedies constricted blood vessels adding to the misperception that abnormal blood flow was key to the disorder Bigal says The first such drugs called ergotamines were powerful vasoconstrictors derived from the ergot fungus which grows on rye and other grains and led to mass poisonings in the Middle Ages Large doses of the fungus can cause seizures psychosis and gangrene in the limbs—a syndrome some called St Anthony’s fire—but doctors found that small doses could help prevent women from hemorrhaging after childbirth and they sometimes relieved migraines V ALTOUNIAN/SCIENCE Yet even refined synthetic versions of ergotamine can dangerously narrow blood vessels so doctors and patients welcomed the triptans which selectively constrict the blood vessels of the brain Introduced in the 1990s and still the most widely prescribed migraine-specific drugs triptans can head off a migraine attack in roughly 50% to 60% of people who take them They don’t work for everyone however and they share an unpleasant side effect with ergots and many pain medications: If a person takes them frequently their headaches may become more frequent and severe Although both ergotamine and triptans act on blood vessels studies that began in the 1990s “torpedoed” the idea that dilated vessels actually cause migraines says neurologist Jes Olesen of the University of Copenhagen Particularly important he notes have been a series of detailed functional magnetic resonance imaging (fMRI)–based blood vessel studies showing no relationship between abnormal blood flow in the brain and the pain of migraine attacks As the blood vessel theory of migraines unraveled researchers looked to other potential triggers One was a disruption of normal electrical activity in the brain: a seizurelike phenomenon called cortical spreading depression (CSD) Strongly associated with the aura many migraineurs get this slow wave of abnormal neuronal excitation usually begins in the occipital lobe at the back of the brain and spreads over it at a rate of roughly 2 mm to 3 mm per minute says Michael Moskowitz a migraine researcher at Harvard University In its wake neuronal activity is temporarily depressed Genetic studies of people with inherited forms of migraine and some animal studies suggest that CSD plays a central role in many if not all migraines Moskowitz says Of the 41 gene variants the studies have linked to migraine risk many are in genes that modulate electrical activity in neurons and are thought to make carriers more susceptible to CSD Based on experiments in rodents Moskowitz believes CSD can trigger migraines by irritating a network of neurons the trigeminovascular system which innervates cerebral blood vessels Moskowitz’s lab discovered the system at the Massachusetts Institute of Technology in Cambridge in the 1980s when they traced a group of fine nerve fibers radiating from blood vessels in the meninges—delicate membranes that envelop the brain and spinal cord—to the trigeminal nerve which innervates the face head and jaw Moskowitz proposed that migraine pain arises when these fine nerves are irritated or stimulated by CSD or other factors He also suggested that blocking the release of Substance P—the only pain-signaling neurotransmitter known at the time—in these nerves might ease migraineurs’ symptoms Although many found the hypothesis compelling multiple trials of drugs designed to block the activity of Substance P failed to head off acute attacks in migraine patients Today although most researchers agree that a hypersensitive trigeminovascular system is likely the source of pain in migraines few would argue that CSD is the only or most important factor in inflaming it Moskowitz says For one thing most people who get the headaches don’t experience the visual aura thought to be a consequence of CSD And only a handful of brain imaging studies have actually shown hints of CSD in human migraineurs These experiments however are difficult to conduct because they require deliberately sparking a migraine right before putting a person in an fMRI scanner In 2001 Moskowitz performed what many in the field describe as the most compelling demonstration of CSD’s link to migraines in an engineer who was able to trigger his own migraines through exercise—in this case playing basketball for 80 minutes before Moskowitz and colleagues recorded his brain activity THE FAILURE of the Substance P–blocking drugs opened the door for CGRP an obscure 37–amino acid peptide discovered largely by accident by neuroscientists Susan Amara and Michael Rosenfeld of the University of California San Diego While studying a thyroid hormone called calcitonin which helps regulate the body’s sodium and calcium levels Amara and Rosenfeld found that the same gene that encodes calcitonin in the thyroid gland produces a slightly different peptide in another part of the brain As one of the earliest examples of alternative gene splicing which enables a single gene to produce multiple proteins the discovery made a splash when it was published in Nature in 1982 After finding CGRP is plentiful in brain pathways that process pain and in brain regions that regulate blood flow neurologist Lars Edvinsson of Lund University in Sweden wondered whether CGRP is involved in migraines His group soon found that CGRP can trigger what was then considered a hallmark sign of migraines: When released from the trigeminovascular nerves it is a powerful vasodilator of cerebral blood vessels In 1990 he paired up with neurologist Peter Goadsby now at King’s College London to further explore CGRP’s role in migraine patients After getting permission to take blood samples from the jugular veins of people who had come to the emergency room for a severe migraine the researchers measured the amounts of a range of different peptides including Substance P during and after attacks “The amazing thing was that CGRP was the only peptide that was significantly released” Edvinsson says I’ve been in this field now for 21 years and this is the most exciting thing we’ve seen so far David Dodick Mayo Clinic At first Edvinsson and others thought CGRP triggered migraines by expanding blood vessels in the brain Instead a growing pile of studies suggested that CGRP was not just a vasodilator but a previously unknown pain-signaling neurotransmitter Other groups found that rising levels of CGRP in jugular blood—not patterns of abnormal blood flow—signaled a migraine attack Then in a pivotal 2002 study Oleson and colleagues injected CGRP into the blood of migraineurs and found that they developed migrainelike headaches within hours whereas nonmigraineurs got at most a mild headache That suggested migraineurs are unusually sensitive to the peptide’s effects Oleson says By the early 2000s the biology around CGRP and migraine was strong enough to inspire a few companies to attempt drug development German pharmaceutical company Boehringer Ingelheim designed a small molecule called bibn4096bs to block CGRP’s receptor The drug could stop acute migraine attacks in some people but produced adverse side effects Another company Merck tried to block the CGRP receptor with a different small compound It too seemed to work modestly well but its trial also had to stop because it showed signs of liver toxicity But the glimmers of efficacy were encouraging says Jaume Pons in San Francisco California who was at that time head of protein engineering at Rinat a spinoff of Genentech that specialized in antibodies to treat cancer Pons and others began to explore other approaches Perhaps antibodies were worth a shot he thought because they can last a long time in the body and can be exceptionally specific reducing the frequency with which people need injections But because most researchers thought it necessary to target migraines in the brain and antibodies are generally too large to pass through the blood-brain barrier they tended to dismiss the option Pons says Back then “most people were not considering the use of antibodies for pain” but Rinat had already begun clinical trials of a different antibody pain treatment with promising initial results he says In 2004 Rinat launched an antibody program targeting CGRP If it worked the team reasoned it would show that it was possible to treat migraines from outside the brain by blocking CGRP only in the peripheral nervous system That would lower the risk of the side effects often provoked by drugs that act in the brain Pons says In a few months the firm developed the peptide-blocking antibody now being tested by Teva under the name TEV-48125 The antibody faced plenty of roadblocks The Rinat team managed to launch a phase I study testing TEV-48125’s safety but Pfizer acquired the company in 2006 and by 2011 the firm “decided that migraine was not an area it wanted to pursue” Pons says Other big companies had made similar decisions at the time Pons says The Food and Drug Administration (FDA) has especially stringent safety standards for pain treatments and estimates for the market value of a new migraine drug are uncertain ranging wildly from roughly $200 million several years ago to $5 billion making it hard for companies to commit a large amount of money to drug development Despite the risk in 2013 a venture capital company called venBio bought the rights to TEV-48125 and launched a new company called Labrys Biologics and continued the antibody’s clinical development Neuroscientist Corey Goodman a managing partner of venBio in San Francisco California had until 2009 been president of the biotherapeutics division at Pfizer where he oversaw Rinat and Pons’s team Goodman remembered TEV-48125 was a “very good antibody” and after recruiting more investors Labrys kicked off two phase II trials in people with frequent migraines The trials produced “the most beautiful phase II data I’ve ever seen” Goodman says with significant reductions in number of headache days over placebo even for the most severe cases Teva bought Labrys in 2014 and is now racing with Alder Biopharmaceuticals Eli Lilly and Amgen to win FDA approval for the first migraine antibody drug So far the four phase II clinical trials at least one from each firm have produced similarly encouraging results with up to 15% of participants experiencing complete relief Goodman says: “I don’t think it’s too early to start talking about a cure for some patients suffering from this debilitating disease” One of the superresponders is 26-year-old Julia Berner who has been getting a migraine every day since she was a little girl Over the years she’s tried epilepsy medications Chinese remedies and nerve blocks among countless other treatments with no success Within a few days of receiving four shots of Teva’s thick viscous antibody-containing solution in the back of her arms and the skin around her hips however the migraines disappeared The difference was “mind-blowing” she says Berner usually spends her days avoiding any small disturbance that could make her constant low-grade migraines more severe After getting the antibody injections that burden lifted “I hadn’t realized how tired they make me” she says “Everyone around me noticed the change in my demeanor” DESPITE SUCH ANECDOTAL SUCCESSES some migraine researchers don’t think it’s time to celebrate yet If CGRP “really is a fundamental mechanism you would expect a much higher proportion of patients to be completely free of attacks” Ferrari says Safety also concerns him because of CGRP’s natural role in dilating arteries and maintaining blood supply to the heart and brain “Theoretically if you block CGRP you could translate a minor stroke or cardiac ischemia … into a full blown stroke or heart attack” he says So far the companies say they haven’t seen that or other significant side effects in the several thousand people who have completed phase I and II trials but the drugs have only been administered for up to 6 months—not long enough to judge long-term effects Bigal says Still the fact that CGRP antibodies can prevent migraines in some fraction of patients is a “really cool finding” from a research perspective says Andrew Russo a molecular physiologist and neurologist at the University of Iowa in Iowa City who consults for Alder The trial results confirm that CGRP is a major new player in migraines—and perhaps even the fundamental trigger—even though the chain of events remains murky “We don’t really know what’s going on but we have some ideas” Russo says One view is that the increased amounts of CGRP released at the start of a migraine sensitize the trigeminal nerve to what are normally innocuous signals resulting in inflammation in the nerves that is relayed to the brain as a pain signal In that scenario Dodick says a migraineur’s brain is like a car with a heightened alarm system that “goes off simply because you walked close to it” In the end the brain reaches what Sigal describes as a “permissive” state in which normal light becomes very bright normal sounds very loud “and you can smell a perfume two blocks away from Bloomingdale’s” CGRP-binding antibodies help turn down the volume in the trigeminal nerve by “mopping up” excess peptide or preventing it from binding to and activating cells Dodick proposes But why are migraineurs more sensitive to CGRP—or produce too much of it—in the first place Some researchers loop back to CSD which certain animal studies suggest can trigger a surge of CGRP Russo says In that case genetic predisposition to the abnormal brain activity could lead to many migraines A growing number of studies point to another important factor: stress Even minor insults such as missing a few hours’ sleep can often “push the migraine brain over the line into having an attack” Sigal says And experiments in rats and cultured cells show that corticotropin-releasing hormone which the body releases in response to stress also increases neuronal production of CGRP Russo says Strikingly many migraine medications also boost CGRP in animal models possibly explaining why people who use drugs like triptans too frequently end up with more severe migraines he says That the relatively large CGRP-blocking antibodies can prevent migraines in some people have convinced most in the field that it is indeed possible to stop the headache from outside the central nervous system even though it is clearly a brain disorder according to Moskowitz “The evidence is favoring that [the drugs are] working somewhere on the trigeminal connections into the brain not in the brain itself unless there’s some massive change” in the permeability of the blood-brain barrier during an attack he says Some researchers however still argue that the CGRP-blocking antibodies must be getting past the blood-brain barrier into the brainstem—even in trace amounts—to be effective Goadsby favors this view and notes that some sections of the brainstem are not very well protected by the barrier Whatever the resolution to that debate the discovery of CGRP’s migraine connection underscores the value of carefully dissecting the neural pathways that lead to pain and searching for a linchpin molecule Moskowitz says If CGRP fulfills its promise as a blockbuster pain target that success could signal to drug developers that effective treatments for other complex and seemingly intractable pain disorders such as fibromyalgia are also within reach Moskowitz says Eli Lilly is already testing its CGRP-antibody in people with cluster headaches which occur in regular cyclical patterns and can be even more painful than migraines As for Sundquist she’s well aware of the clinical trials for the various CGRP-related drugs and she is hopeful But the random assortment of failed remedies that fills her closet—antidepressants nutritional supplements a headband that transmits painful electric zaps to her scalp and “looks like something from Star Trek”—makes her wary as well “I’m just waiting for more information and praying that I will be healthy again” compartmentalised ethnically, an exhibition of works by 22 artists, but their coverage is sparse and they can be challenging and expensive to install and maintain, a seismic observatory proposed by the researchers would be relatively inexpensive to operate. the first day of the match, The sun has been making a belated appearance over the city in the past couple of days.China plans to put drone swarming technique for military use Compared with Wing Loong I.

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" NASA Administrator Charles Bolden said during a town hall meeting here today at the University of Tokyo (Todai).seriously. Flying or sex. and 35 detentions.

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