medical news

Scratching Away at the Mystery of Itch

The sensation of feeling itchy is pretty universal, and yet scientists still don’t completely understand the complex processes that give us the urge to scratch.

Itching can be annoying, but like pain, a little bit can be a good thing. Itching can help people learn to avoid dangers such as mosquitoes carrying malaria, or poison ivy. But many people suffer from chronic itch, which has no direct cause and can be a debilitating condition with few options for relief.

“When people hear about itch, they think about a mosquito bite or chicken pox, which is irritating but very temporary,” said Diana Bautista, a cell and developmental biologist at the University of California, Berkeley, who wrote an article summarizing our current understanding of itch

Bautista said people often laugh when she tells them she studies itch. But “from a clinical perspective, chronic itch is a really widespread problem, and incredibly difficult to treat,” she told LiveScience.
Itch, or ouch?

Like the feelings of touch, temperature and pain, itching involves a complex system of molecules, cells and circuits reaching from the skin into the brain. Most over-the-counter treatments for itching target histamine, a compound involved in inflammation. But many kinds of itch can’t be treated with antihistamines or other available treatments.

Skin conditions such as eczema and psoriasis, systemic conditions including multiple sclerosis, and even some cancers, can all lead to chronic itch, which affects about 10 percent of the world’s population at some point during their lives, Bautista said.

Recent research on itch is revealing its mysterious relationship with pain, according to the paper. For example, scientists have found that the reason scratching an itch offers relief is because scratching causes pain, which suppresses the itch, at least temporarily. They’ve also found that the cells and circuits that transmit pain and itch overlap somewhat.

But although pain can block out itch, some painkillers – such as morphine – can cause itchiness. And some things that cause itch also cause pain, such as capsaicin, the ingredient that makes chili peppers hot.

Scientists now have several theories about this odd connection between pain and itch. One theory suggests the same set of neurons produce an itch when activated slightly, but result in pain when activated fully. Alternatively, different cells might trigger pain and itch signals, but the signals might interact in the spinal cord. There is some evidence for both ideas, Bautista said.

Itching to understand

But itch and pain don’t always go together.

For example, the antimalarial drug chloroquine is known to have a side effect of severe itch. In one recent study, scientists bred mice to have nerves that lacked a receptor that responds to chloroquine. These mice didn’t show signs of itching, but they did have normal responses to pain. The findings suggest these nerve cells are required for itch, but not necessarily for pain, the researchers said.

Many itch receptors found in mice are also found in humans. Often, researchers take molecules known to play a role in chronic itch in humans, and study the effects in mice that lack these molecules.

From this research, scientists have identified some of neurons and signals involved in chronic itch, but the search for treatments continues.

“It’s an exciting time, because there have been a lot of basic discoveries in the last five years,” Bautista said.

Some promising treatment approaches involve targeting receptors on immune cells, which may be somewhat effective against forms of itch that can’t be treated with anti-histamines.

“As we learn more about the system, and which cell types we should target,” Bautista said, “I think we’re going to be able to treat chronic itch more effectively.”

Source: huffington post

Breath Test May Detect Signs of Lung Cancer: Study

Examining breath samples from patients with suspicious growths might help determine who needs surgery

Researchers tested the exhaled breath of people with suspicious lung lesions that were detected on CT scans. The breath was tested for levels of four cancer-specific substances, called “carbonyls.”

The breath samples were analyzed using a special device developed at the University of Louisville.

Having elevated levels of three of the four carbonyls was predictive of lung cancer in 95 percent of patients, while having normal levels of these substances was predictive of a noncancerous growth in 80 percent of patients, the researchers found.
Elevated carbonyl levels returned to normal after lung cancer patients had surgery to remove the cancer, according to the study, which was to be presented Tuesday at the Society of Thoracic Surgeons annual meeting in Orlando, Fla.

“Instead of sending patients for invasive biopsy procedures when a suspicious lung mass is identified, our study suggests that exhaled breath could identify which patients” may be referred for immediate surgery, study author Dr. Michael Bousamra, of the University of Louisville, said in a society news release.

This approach offers something new, he said, including “the simplicity of sample collection and ease for the patient.”

The data and conclusions of research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

Source: webmd

Unique brain area that makes us human identified

Oxford University researchers have identified an area of the human brain that is known to be intimately involved in some of the most advanced planning and decision-making processes that we think of as being especially human.

“We tend to think that being able to plan into the future, be flexible in our approach and learn from others are things that are particularly impressive about humans. We’ve identified an area of the brain that appears to be uniquely human and is likely to have something to do with these cognitive powers,” senior researcher Professor Matthew Rushworth of Oxford University’s Department of Experimental Psychology said.

MRI imaging of 25 adult volunteers was used to identify key components in the ventrolateral frontal cortex area of the human brain, and how these components were connected up with other brain areas. The results were then compared to equivalent MRI data from 25 macaque monkeys.

This ventrolateral frontal cortex area of the brain is involved in many of the highest aspects of cognition and language, and is only present in humans and other primates.

Some parts are implicated in psychiatric conditions like ADHD, drug addiction or compulsive behaviour disorders.

Language is affected when other parts are damaged after stroke or neurodegenerative disease.

A better understanding of the neural connections and networks involved should help the understanding of changes in the brain that go along with these conditions.

The findings are published in the science journal Neuron.

Source: Business standard

 

High-tech scan a boon for bone marrow cancer patients

Here comes a unique Magnetic Resonance Imaging (MRI) scan that could improve care for bone marrow cancer patients, says IANS.

The new whole-body, diffusion-weighted MRI scans showed the spread of cancer throughout the bone marrow of patients with myeloma – one of the most common forms of blood cancer – more accurately than standard tests.
The scans also showed whether the patients were responding to cancer treatments, said researchers at the Institute of Cancer Research, London, and the Royal Marsden NHS Foundation Trust. In the study, 26 patients had whole-body MRI scans before and after treatment.

In 86 percent of cases, experienced doctors trained in imaging were able to correctly identify whether patients responded to treatment. The doctors also correctly identified those patients who weren’t responding to treatment 80 percent of the time.
Using the scanning technique, doctors could pinpoint exactly where the cancer was in the bones, with the results available immediately. Conventional tests include bone marrow biopsies and blood tests but neither shows accurately where the cancer is present in the bones.

“This is the first time we’ve been able to obtain information from all the bones in the entire body for myeloma in one scan without having to rely on individual bone X-rays,” said Nandita deSouza, professor of translational imaging at the Institute of Cancer Research.

“We can look on the screen and see straight away where the cancer is and measure how severe it is. The scan is better than blood tests which don’t tell us in which bones the cancer is located,” she added. “It also reduces the need for uncomfortable biopsies which do not reveal the extent or severity of the disease,” said the study.
“In the future, we hope this new tool would help doctors extend the life of more myeloma patients,” added Faith Davies, member of the Myeloma targeted treatment team at the Institute of Cancer Research and honorary consultant at The Royal Marsden.

Source: The Free Press Journal

Famous Amnesia Patient’s Brain Cut into 2,401 Slices

Image of the frozen brain at the level of the temporal lobes during the cutting procedure.

A new examination of the brain of Patient H.M. — the man who became an iconic case in neuroscience when he developed a peculiar form of amnesia after parts of his brain were removed during surgery in 1953 — shows that his surgeon removed less of his brain than thought.

At age 27, H.M., whose real name was Henry Molaison, underwent an experimental surgical treatment for his debilitating epilepsy. His surgeon removed the medial temporal lobe, including a structure called the hippocampus.

Thereafter, H.M. was unable to form new memories. His case brought about the idea that the hippocampus may have a crucial role in retaining learned facts, replacing the notion that memories are scattered throughout the brain. H.M. became the focus of more than 50 years of memory research, working closely with the researchers who had to introduce themselves every time they met.

“Much of what we know about human memory, it has one way or another to do with H.M.,” said study researcher Jacopo Annese, director of The Brain Observatory in San Diego.

After H.M.’s death in 2008, Annese and his colleagues cut the patient’s frozen brain into 2,401 slices, each 0.7-millimeters thick. They took a picture of every slice, and created a high-resolution, 3D model of his brain.

In the new study detailed online today (Jan. 28) in the journal Nature Communications, they report that a significant portion of the hippocampus, which was thought to have been removed in surgery, was actually intact.

What happened to H.M.?

Research on H.M. showed that there are in fact different kinds of memory. He was unable to learn new facts, remember the events happening around him or learn people’s names, but he was able to recall events from his childhood. He also could learn skills, for example, he could get better at a new motor task with practice.

“Over 50 years of studies, the picture [of memory] was a little bit complicated,” because H.M. had some types of memory but not others, Annese said.

The only way to start teasing out H.M.’s memory impairment in light of the anatomy of the brain was to know what exactly had happened during the surgery

Until the 1990s, the researchers had only sketches drawn by the surgeon, Dr. William Scoville, to refer to. But after the advent of neuroimaging, researchers scanned H.M.’s brain in 1992 and found that a portion of the hippocampus had been spared.

In the new study, Annese and his colleagues measured the exact length of H.M.’s hippocampus, and found the spared portion was even larger than what brain scans had shown.

The posterior part of the hippocampus deals with memory, and the brain slices show this part wasn’t removed, and in fact, was undamaged at the cellular level, the researchers said.

“The most beautiful finding I think was the fact that we realized … that Scoville missed the posterior hippocampus,” Annese said.

The memory impairment

The new findings shed light on what happened to H.M., but likely won’t revolutionize what researchers know about memory, and are in fact in line with modern views of hippocampal function

Almost all connections from the hippocampus to the cortex go through a part of the temporal lobe called the entorhinal cortex, which Annese found had been removed from H.M.’s brain. As this region connects the hippocampus to other brain regions, the surgery may have nearly isolated the hippocampus from the rest of the brain.

This may mean that H.M.’s amnesia had more to do with the entorhinal cortex being removed, than with the parts of the hippocampus being removed, Annese said, although more study is needed to know for sure.

The new study presents “an extremely detailed post-mortem investigation of the remaining anatomy of [H.M.’s] brain,” said Neil Burgess, a memory researcher at University College London, who wasn’t involved in the new analysis. “These extra details will no doubt continue to fuel the debate as to which bits of the medial temporal lobe are responsible for which aspects of memory.”

Source: live science

Anti-VEGF drugs making a difference in vision, longterm care

eye

A treatment introduced less than 10 years ago has already made a difference in the number of Americans losing their vision and being admitted to nursing homes, according to a new study.

Two Duke University economists looked at Medicare beneficiaries with so-called “wet” macular degeneration and found those diagnosed after the introduction of anti-VEGF drugs were less likely to go blind and less likely to move into long-term care.

“At last we have found a way of managing this horrible and very common disease among the oldest of the old,” said Frank Sloan, who led the new study.

Age-related macular degeneration (AMD) is the number one cause of blindness in the U.S. affecting older adults, usually after age 65. Most AMD patients have the dry form of the disease, but about 10 percent have wet AMD, which progresses more quickly than the dry form.

Past treatments weren’t very effective at managing wet AMD, but retinal surgeons began using injections of vascular endothelial growth factor inhibitors, known as anti-VEGF, in the mid 2000s.

Previous clinical research has indicated that anti-VEGF treatments are effective for wet AMD, but Sloan said those types of studies don’t let you see longer-term outcomes or how well the therapy works in a real-world setting.

The researchers used Medicare claims information from 1994 to 2011 to examine the vision outcomes and long-term care facility admissions of wet AMD patients who were treated with older methods or with the new anti-VEGF drugs.

The two most commonly used drugs, ranibizumab (Lucentis) and bevacizumab (Avastin), were introduced for eye therapy in 2006.

The researchers discovered that the use of anti-VEGF therapy reduced vision loss by 41 percent and the onset of severe vision loss and blindness by 46 percent, compared to earlier forms of treatment.

They also found that patients who received anti-VEGF were 19 percent less likely to be admitted to long-term care facilities during a two-year follow-up period compared to those treated before the drugs came into use.

The findings were published in JAMA Ophthalmology.

The new treatments may be changing the way some doctors think about wet AMD.

“We used to say it was better to have the dry form because it tended to be milder and slowly progressive as opposed to the wet AMD, which has a rapid onset and much more severe vision loss,” Dr. Michael Stewart told Reuters Health.

Stewart, who chairs the ophthalmology department at the Mayo Clinic in Jacksonville, Florida, was not involved in the new study.

Stewart said results like these actually call into question whether or not that old statement is still true because the anti-VEGF drugs are so effective.

“By and large, we are maintaining good vision in most people that we treat,” Stewart said.

Stewart also says the new drugs have revolutionized the way retinal surgeons approach these patients.

He says that early diagnosis with quick initiation of treatment is the best way of preserving vision. The typical course of treatment is to give an injection of the drug in to the eye, about one time per month, but treatment can be tapered to the patients’ needs.

“Patients and family – and most of us, actually – think of a needle in the eye as one of the worst medical procedures we can imagine,” Stewart said, “but the reality is patients tolerate them very, very well and very few patients actually forgo the treatment because of either imagined or real pain, discomfort and anxiety.”

Source: Reuters

Synthetic organ technology moving forward

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Since 2008, eight patients have successfully undergone procedures in which their badly-damaged tracheas were replaced with man made windpipes.

Now, a Boston-area company is preparing to manufacture the scaffolds used to grow these synthetic organs on a large scale, MIT Technology Review reported.

Harvard Apparatus Regenerative Technology (HART) makes synthetic windpipes by growing a patient’s own stem cells on a lab-made scaffold. The company is working with the U.S. Food and Drug Administration to test the system and is currently conducting trials in Russia.

Researchers hope that in the future, this scaffolding technique could be used to grow other organs as well, such as an esophagus, heart valve or kidney. If successful, the technology could help provide a solution to the country’s organ transplant shortage.

The U.S. Department of Health and Human Services estimates there are 120,000 people on waiting lists for an organ and this number underestimates the actual need, Joseph Vacanti, a surgeon-scientist at Massachusetts General Hospital and a leader in tissue-engineering research, told MIT Technology Review.

“The only way we are going to meet that real need is to manufacture living organs,” Vacanti, who is not affiliated with HART, said.

Source: Top news today

 

The Older Mind May Just Be a Fuller Mind

People of a certain age (and we know who we are) don’t spend much leisure time reviewing the research into cognitive performance and aging. The story is grim, for one thing: Memory’s speed and accuracy begin to slip around age 25 and keep on slipping.

The story is familiar, too, for anyone who is over 50 and, having finally learned to live fully in the moment, discovers it’s a senior moment. The finding that the brain slows with age is one of the strongest in all of psychology.

Over the years, some scientists have questioned this dotage curve. But these challenges have had an ornery-old-person slant: that the tests were biased toward the young, for example. Or that older people have learned not to care about clearly trivial things, like memory tests. Or that an older mind must organize information differently from one attached to some 22-year-old who records his every Ultimate Frisbee move on Instagram.

Now comes a new kind of challenge to the evidence of a cognitive decline, from a decidedly digital quarter: data mining, based on theories of information processing. In a paper published in Topics in Cognitive Science, a team of linguistic researchers from the University of Tübingen in Germany used advanced learning models to search enormous databases of words and phrases.

Since educated older people generally know more words than younger people, simply by virtue of having been around longer, the experiment simulates what an older brain has to do to retrieve a word. And when the researchers incorporated that difference into the models, the aging “deficits” largely disappeared.
“What shocked me, to be honest, is that for the first half of the time we were doing this project, I totally bought into the idea of age-related cognitive decline in healthy adults,” the lead author, Michael Ramscar, said by email. But the simulations, he added, “fit so well to human data that it slowly forced me to entertain this idea that I didn’t need to invoke decline at all.”

Can it be? Digital tools have confounded predigital generations; now here they are, coming to the rescue. Or is it that younger scientists are simply pretesting excuses they can use in the future to cover their own golden-years lapses?

In fact, the new study is not likely to overturn 100 years of research, cognitive scientists say. Neuroscientists have some reason to believe that neural processing speed, like many reflexes, slows over the years; anatomical studies suggest that the brain also undergoes subtle structural changes that could affect memory.

Still, the new report will very likely add to a growing skepticism about how steep age-related decline really is. It goes without saying that many people remain disarmingly razor-witted well into their 90s; yet doubts about the average extent of the decline are rooted not in individual differences but in study methodology. Many studies comparing older and younger people, for instance, did not take into account the effects of pre-symptomatic Alzheimer’s disease, said Laura Carstensen, a psychologist at Stanford University.

Dr. Carstensen and others have found, too, that with age people become biased in their memory toward words and associations that have a positive connotation — the “age-related positivity effect,” as it’s known. This bias very likely applies when older people perform so-called paired-associate tests, a common measure that involves memorizing random word pairs, like ostrich and house.

“Given that most cognitive research asks participants to engage with neutral (and in emotion studies, negative) stimuli, the traditional research paradigm may put older people at a disadvantage,” Dr. Carstensen said by email.

The new data-mining analysis also raises questions about many of the measures scientists use. Dr. Ramscar and his colleagues applied leading learning models to an estimated pool of words and phrases that an educated 70-year-old would have seen, and another pool suitable for an educated 20-year-old. Their model accounted for more than 75 percent of the difference in scores between older and younger adults on items in a paired-associate test, he said.

That is to say, the larger the library you have in your head, the longer it usually takes to find a particular word (or pair).

Scientists who study thinking and memory often make a broad distinction between “fluid” and “crystallized” intelligence. The former includes short-term memory, like holding a phone number in mind, analytical reasoning, and the ability to tune out distractions, like ambient conversation. The latter is accumulated knowledge, vocabulary and expertise.

“In essence, what Ramscar’s group is arguing is that an increase in crystallized intelligence can account for a decrease in fluid intelligence,” said Zach Hambrick, a psychologist at Michigan State University. In a variety of experiments, Dr. Hambrick and Timothy A. Salthouse of the University of Virginia have shown that crystallized knowledge (as measured by New York Times crosswords, for example) climbs sharply between ages 20 and 50 and then plateaus, even as the fluid kind (like analytical reasoning) is dropping steadily — by more than 50 percent between ages 20 and 70 in some studies. “To know for sure whether the one affects the other, ideally we’d need to see it in human studies over time,” Dr. Hambrick said.

Dr. Ramscar’s report was a simulation and included no tested subjects, though he said he does have several memory studies with normal subjects on the way.

For the time being, this new digital-era challenge to “cognitive decline” can serve as a ready-made explanation for blank moments, whether senior or otherwise.

It’s not that you’re slow. It’s that you know so much.

Source: New York Times

 

Man dies after 8 hours in ER waiting room

Reports have emerged that a man died in a hospital waiting room in New York City more than eight hours after he sought emergency care.

According to multiple reports, 30-year-old John Verrier entered the emergency room of St. Barnabas Hospital in the Bronx at around 10 p.m. on Jan. 12 complaining about a rash. He was found dead in the waiting room about 6:40 a.m. the next day when a guard failed to wake him up.

St. Barnabas Hospital spokesperson Steve Clark confirmed the timeline around Verrier’s death.

“Probably this scenario in this shape and form has happened in any big hospital in New York City,” he said.

When Verrier arrived at St. Barnabas, he had his vitals taken in the triage area and was told to wait in the waiting room until his name was called to see a doctor, according to Clark. At 12:35 p.m., his name was called for the first time, but Verrier did not respond. That night, his name was called two more times to see the doctor, but the patient did not acknowledge his name was being called.

“People have personal responsibility when your name is called, you have to get up and see the doctor,” Clark said.

It was determined through employee accounts and security footage that Verrier was alive at least until 3:45 a.m. A security guard woke him up after he had fallen asleep, and he had been recorded walking around the waiting room.

The cause of death for Verrier has yet to be determined, pending a medical examiners report.

The case has been investigated internally, and the hospital said it was determined that officials had done everything according to protocol.

“This could have happened anywhere outside in the cold,” said Clark.

He couldn’t confirm the reason Verrier was asking to see a doctor, citing patient confidentiality laws. He did say that Verrier was called for as soon possible, after more pressing cases were attended to.

“It was a busy night, waiting 2 hours and 30 minutes is not that long a time considering what his complaint was,” Clark said.

He added that on many cold nights in New York City, many people use the hospital as shelter and stay in the waiting room to keep warm. People aren’t allowed to loiter or sleep in the facilities, however. In order to stay inside the hospital, the patients have to come in with a medical complaint. Many of the times, the issue they present with is just a ruse in order not to be kicked out, he said.

He emphasized that this scenario may or may not relate to Verrier’s case, but could explain why some people spend time sitting in a waiting room without entering the hospital, even if their name was called multiple times.

“People come in with no desire to see the doctor,” he said.

An anonymous St. Barnabas Hospital emergency room employee told WABC that despite Verrier’s name being called three times, he had not been checked on personally. The employee added he or she believed Verrier died because there was “not enough staff to take care of the number of patients we see each day.”

Clark dismissed the comments, saying that the hospital did not think staff numbers played a role in this scenario.

“It is a tragedy that a young man died, yet following an internal review, it was concluded that all hospital guidelines were met,” the hospital said.

According to a ProPublica report, the average person in New York spends 2 hours and 35 minutes waiting in the emergency room to see a doctor, and about 1 percent leave without being seen. The report determined that St. Barnabas patients waited 5 hours and 6 minutes on average before seeing a doctor, and 18 percent left without being seen.

Source: fox news

Pepsi One and Potential Cancer-Causing Chemical

Pepsi One has higher levels of a potential cancer-causing chemical than other soft drinks, according to a study released Thursday by Consumer Reports magazine.

Researchers looked at levels of a chemical called 4-methylimidazole (4-MeI), which is found in artificial caramel coloring used in soft drinks. There are no federal limits on the chemical’s use, but California requires warning labels on foods or beverages that expose consumers to more than 29 micrograms of 4-MeI a day, the Los Angeles Times reported.

The Consumer Reports study said that 12-ounce cans of the low-calorie soft drink Pepsi One bought in California contained as much as 43.5 micrograms of 4-MeI, and that a nonalcoholic malt beverage called Malta Goya had as much as 352.5 micrograms of the chemical, the Times reported.

In contrast, cans of Coca-Cola and Dr. Pepper contained 4.3 micrograms and 10.1 micrograms, respectively, of 4-MeI, the Times said.

A person would have to drink more than 1,000 cans of soda a day to reach the levels of 4-MeI linking the chemical and cancer in rodents, according to the U.S. Food and Drug Administration, the newspaper reported.

In 2012, both Coca-Cola Co. and PepsiCo Inc. promised to reduce the amount of 4-MeI in their drinks, the newspaper said.

“We are concerned about both the levels of 4-MeI we found in many of the soft drinks tested and the variations observed among brands, especially given the widespread consumption of these types of beverages,” said Urvashi Rangan, a toxicologist and executive director of the Consumer Reports Food Safety and Sustainability Center, the Times reported.

Pepsi disputed the study findings. The soda maker said levels of 4-MeI in its drinks did not equal 29 micrograms a day because “the average amount of diet soda consumed by those who drink it is approximately 100 [milliliters] per day, or less than a third of a 12 [ounce] can,” the Times reported. Goya Foods Inc. refused comment, the newspaper said.

Consumer Reports has asked the California attorney general to investigate whether Pepsi One and Malta Goya should have warning labels, the Times reported.

Source: Web md