Day: 09/21/2012

U.S. invests $60 million in clean energy buses.

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Getting around on mass transit is already the cleaner commuting option. Now the U.S. Department of Transportation wants to help transit agencies take it a step further.

The Federal Transit Administration is investing $59.3 million, through the Clean Fuels Grant Program, in 27 projects that reduce emissions from buses and improve fuel economy.

“President Obama is committed to investing in sustainable transportation systems that improve access to jobs, education and medical care for millions of riders, while bringing cleaner air to our communities and reducing our dependence on oil,” said U.S. Transportation Secretary Ray LaHood in a statement. “These projects will also help transit agencies operate more efficiently, and save money in the long run.”

The grants will support transit agencies in switching from older diesel buses to hybrid-electric buses, compressed natural gas buses, or 100 percent electric buses. In addition to bus replacement, the funds will help cities build fueling stations for buses that use alternative fuels and purchase batteries for hybrid buses.

While 27 projects were funded, there were 146 projects seeking funds amounting to over $500 million in desired bus upgrades.

Investing in cleaner buses makes sense in light of the fact that transit ridership continues to rise in the United States. In 16 of the last 19 month transit ridership has increased. Last July alone transit ridership was up 2.5 percent over the past 12 month period.

At the same time, electric and hybrid bus purchases are also on the rise. In North America, hybrid models account for about 40 percent of new bus purchases, according to Pike Research. And from 2012 to 2018 the electric bus market is expected to grow by 26 percent.

Source: smart planet

Scientists create replacement organs using body’s own cells.

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One of the problems of organ transplants is the potential for the body to reject the foreign organ. For this reason, organ donor recipients have to take drugs that suppress the immune system.

Scientists are having preliminary success with a new way to get patients new organs that they may need: bioartificial organs made of plastic and the patient’s own cells.

So far, only a few such organs have been created and transplanted, and the they aren’t complex organs — just simples one like bladders and a windpipe. But, the New York Times reports, scientists are working on creating more complex organs such as kidneys and livers with these techniques.

A windpipe made to order

The Times article features the case of Andemariam Beyene, whose doctors discovered a golf ball-sized tumor growing in his windpipe two-and-a-half years ago. When he was nearly out of options for treatment, he went to see Dr. Paolo Macchiarini, at the Karolinska Institute in Stockholm, who suggested making Mr. Beyene a windpipe out of plastic and his own cells.

In order to make it, Dr. Macchiarini began by using a porous, fibrous plastic to make a copy of Mr. Beyene’s windpipe. He then seeded it with stem cells from Mr. Beyene’s bone marrow and placed the windpipe in an incubator that spun the windpipe “rotisserie-style,” says the Times, in a nutrient solution.

Then, he substituted that in for Mr. Beyene’s cancerous windpipe.

Fifteen months after surgery, Mr. Beyene is cancer-free.

The blueprint

Scientists are looking to nature to guidance on how to create these bioartificial organs.

In Dr. Macchiarini’s lab, a researcher named Philipp Jungebluth took a heart and lungs from a rat and put them in a glass jar. A detergent-like liquid connected via tube dripped into the jar and out, slowly stripping the organs of their living cells. After all the cells were gone (in three days), what was left of the organs was the scaffold, the basic shape of the organ, composed of a matrix of proteins and other compounds that keep the right cells in the right places.

Human scaffolds could be better for building new organs than synthetic scaffolds that just try to imitate nature. For example, donor lungs could be stripped of cells and re-seeded with a patient’s own cells before implantation.

Dr. Macchiarini has used scaffolds to successfully replace windpipes from cadavers in about a dozen patients who don’t have the major problem facing other organ donor recipients: the risk of organ rejection.

But scaffolds still have some problems of traditional organ transplants: They require donor organs, for which there is a long waiting list, and the patient has to wait for the organ to be stripped of cells. Also, when it comes to windpipes, a donated windpipe may not be the right size. For that reason, Mr. Beyene’s windpipe, made of the plastic replica of his own windpipe, fit perfectly.

Dr. Macchiarini is looking at future improvements on this still preliminary work: The Times reports that someday, re-seeding the cells of a new organ may not take place outside the body:

“Instead, he envisions developing even better scaffolds and implanting them without cells, relying on drugs to stimulate the body to send cells to the site. His ultimate dream is to eliminate even the synthetic scaffold. Instead, drugs would enable the body to rebuild its own scaffold.”

“Don’t touch the patient,” Dr. Macchiarini told The Times. “Just use his body to recreate his own organ. It would be fantastic.”

Source: The New York Times /Smart planet

In Melbourne, designing future bodies.

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Imagine you could take a pill that lets you sweat perfume; have an electronic tattoo that could be augmented by touch; or wear a dress that blushes and shivers with your emotions. No, this isn’t the stuff of sci-fi dreams, it’s the far-future designs of Melbourne body architect Lucy McRae.

McRae imagines new ways to merge biology and technology into our own bodies. Her visualizations are fascinating and often unnerving possibilities of what our bodies might look like in the future.

A current TED Fellow, McRae regards the body as a blank canvas for her investigations, a core which she builds layers and concepts on top of. She is driven by an insatiable curiosity and desire to change the way we think about our bodies.

“As a body architect, I find ways of extending the body beyond its physical and biological edge, manipulating the natural silhouette with materials that are draped, injected or bathed over the skin,” she explains.“The outcome can sometimes be surprisingly morbid, imperfect or grotesque, each time I’m never anticipating the final result.”

So what exactly is a body architect? McRae says she is the first and only ‘body architect’ in the world, and gave herself the title to convince HR at Philips FutureLab to hire her. And it worked.

This elusiveness of an understandable job title has allowed her to create a unique specialization based on her diverse background and training.

As a teenager McRae was an athlete, competing in 100-meter hurdle events at State level. She also trained in classical ballet from the age of four until the time she left high school.

“The more projects I complete, the more I understand the influence my ballet training has. I developed a conscious awareness and periphery of understanding people’s body movements and behavior,” she says.

McRae quit ballet because she knew a career in dance was going to be short lived. She went on to design school, and later worked in architecture firms, with a brief stint in the fashion industry.

Today she is based in Amsterdam, returning home to Melbourne on occasion to work on commissioned works. Within the Philips Design Probes team, she examines how technology could impact the human body in 15 to 20 years (known in the industry as ‘far-future’ design).

“Most projects are motivated by the relationship technology has with the human body, inventing and speculating ways of merging the two closer together,” she says.

She has explored this concept in a number of projects, including her low-fi, confronting experiments with friend and Dutch artist Bart Hess.The two work under the moniker LucyandBart.

McRae’s commissioned works has also produced some curious results. The most well known is the liquid textile dress she made for Swedish pop star Robyn on the ‘Indestructible’ music video clip.

More recently, McRae unveiled the film Morphe – a collaboration with the Melbourne skincare brand Aesop.

Morphe is set in a future laboratory in which a scientist administers an assortment of gels, liquids and other beauty treatments to a sleeping muse.

“My work is seeded from instinct. My process is primitive, driven and inspired by my immediate surroundings. I think Aesop has subliminal effects on people. I feel we are both creating alternate worlds which are sincere and unafraid,” she says.

The film has obvious references to both Mary Shelley’s Frankenstein and Charles Perrault’s Sleeping Beauty. But McRae says that the inspiration for the narrative came from the nineteenth-century physicist and philosopher Hermann Ludwig Helmholtz and his observation on human perception, that “everything is an event on the skin.”

She has also finished directing a film for an Australian art patron and restaurant owner which links food and the body in a macabre setting.

“In the film I create an alternative world where we see a lone woman meticulously concocting substances in a morgue-type laboratory. Reproducing ‘life’, she clones humans, mixes genders, and fuses man and woman, like a chef composes food.”

“Each clone has slightly different sensory enhancements in taste or sight which she makes according to her mathematical matrix.”

“I use film as a way of experimenting and testing these ideas, creating alternative worlds where science, technology, architecture and fashion co-exist.

McRae also cites gene mutations as a source of inspiration. And she enthuses over the work of Professor Gregory Sporton, who has developed a vibrating suit used for training elite Olympic gymnasts.

“I like thinking about how this perfecting technology could affect fashion or dance. Imagine having people walking down the street performing obscured alien movements while wearing this vibrational suit,” she says.

It is this ‘what if?’ exploration of the crossover between technology and the body that continues to inform her work.

“The body is soaked in information and I find ways of harnessing that knowledge to innovate and evolve the body. My work blurs and disrupts the physical edges of the human silhouette and its effects on behaviour and communication.”

Source: smart planet

 

Chicago’s new role: hub of the digital heartland.

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In the thick of the industrial revolution, the city of Chicago rose as the heart and hub of production, trading and transportation, thanks to its centralized location on the North American continent. The railroads all converged there, shipping goods from East Coast ports and factories to points west.

When the St. Lawrence Seaway opened — connecting Great Lakes shipping with trans-Atlantic shipping — Chicago also became the gateway for shipping to the middle of the continent. And, again because of it’s centrality, Chicago’s O’Hare International Airport grew to become the one of the world’s busiest airports. And with the interstate highway system, the city is also a trucking hub.

Now, it is reported, Chicago’s place in the middle of the continent is turning the city into the hub of the information age. As Crain’s Chicago Business‘ John Pletz reports, in an economy where online latency can cost a lot of money, the city is ideally situated:

“Chicago is one of the half-dozen key vertebrae in the nation’s digital backbone because it lies at the center of many of the fiber optic cables that stretch between New York and California, the country’s major connection points to the rest of the world via cables under the oceans. Chicago has the third-biggest fiber optic capacity of any metro area in the country, behind New York and Washington. And three of the world’s largest data centers are in Chicago or its suburbs.”

The challenge is that the city’s fiber-optic broadband network — laid in the late 1990s and early 2000s — in now stretched to it’s limit, Pletz writes. Greater coordination between regional governments and expanding more capabilities beyond the city’s central “Loop” area.

The Chicago region’s broadband network is an attraction to companies establishing data centers that need instantaneous connections and communications with the rest of the world. For example, Pletz cites the CME Group Inc., which operates the Chicago futures and commodities exchange. Transactions are delivered and sent across the globe in about 79 milliseconds. More than 200 telecom carriers, a number of internet service providers, and many of the world’s major financial exchanges rely on a data center housed within a former printing plant in the city.

Source: smart planet

 

 

 

 

On track to a better airline trolley.

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It may be too ambitious to elevate lowly airplane meals to the heights of gastronomy, but it is possible to rethink the fusty food carts that ferry them. As part of her graduate work at Staffordshire University, product designer Heather Dunne came up with an innovative concept to solve a ubiquitous problem on commercial aircrafts: immobility.

With a slimmer and more ergonomic design, Dunne’s Orbit “commercial aircraft food delivery system” conserves space, making it easier for flight attendants to maneuver their carts up and down the aisle and passengers to move freely throughout the cabin during meal service — a boon for those requiring frequent bathroom breaks.

The idea, Dunne says, was sparked by a flight to Spain where she observed firsthand the inherent limitations with today’s airplane food carts. “The main problem was the width of economy seating. Passengers on the aisle seats had elbows and legs outstretched in the aisle, making it hard for the large trolley to move past without disrupting them,” she explained to SmartPlanet in an e-mail. “Passengers were unable to get past the food trolley without a lot of hassle.”

Dunne began by poring over airplane design plans and researching galley manufacturers. The most useful fodder for her work came from in-depth discussions with cabin crew members through dedicated forums. “They highlighted a lot of problems with the current trolleys that helped me to develop the project,” she said.

One recurring grievance? Capacity. Current carts can only carry 35 to 40 packaged meals at a time, forcing flight attendants to make frequent trips to the galley to restock which, consequently, increases service wait time. Orbit’s longer form increases its storage capacity to 60 meals, which would require far less back and forth.

But the benefits of the design go well beyond form to tackle function. Dunne has included a pressurized shelf system so that as meals are removed from the top layer of shelves, those underneath slide up and allow the cabin crew to serve passengers without bending down — a feature that would streamline the process, improving working conditions for flight attendants.

Leaving no element unconsidered, Dunne designed Orbit to secure into grooves in the aisles, allowing it to automatically lock in place as a safeguard during periods of turbulence.

The designer’s well-imagined concept addresses one of the biggest blights in current aircraft design and has the potential to revolutionize the in-flight experience.

So how soon might we see Orbit on future flights? Not quite yet. The designer has yet to approach any airlines with the idea, given its infancy. One thing is certain, however: to accommodate her design, current planes would need to install a track within aisles and entirely modify the galley’s layout — a highly unlikely hurdle to a retrofit. But newly commissioned aircraft? That’s another story.

Determined to launch Orbit into air, Dunne hopes to glean advice from industry professionals to get her design on track to adoption. Until then, keep your elbows in close.

Source: Smart planet

 

 

 

Renal Safety of Treatment for Chronic HBV Infection.

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Nephrotoxicity was similar with tenofovir or entecavir.

Both tenofovir and entecavir are considered first-line oral antiviral agents for chronic hepatitis B virus (HBV) infection. In previous studies, nephrotoxicity has been observed with tenofovir therapy in patients coinfected with HBV and HIV. However, whether similar renal toxicity is present during tenofovir therapy in patients with HBV monoinfection is unclear.

This community-based, retrospective study compared nephrotoxicity in 80 patients with HBV infection who were treated with tenofovir (300 mg with varying frequency) — alone or in combination with another antiviral — and in 80 age- and sex-matched patients treated with entecavir alone (0.5 mg or 1 mg with varying frequency). Nephrotoxicity was defined as an incidence of serum creatinine (SCr) 2.5 mg/dL, an increase in SCr of 0.2 mg/dL, a drop in the estimated glomerular filtration rate (eGFR) to <60 mL/min, or an adjustment in medication dosage. The tenofovir and entecavir groups were similar in proportions of patients with diabetes mellitus (20% in each group), history of kidney or liver transplant (20% and 16%), and preexisting renal insufficiency (19% and 13%).

During treatment (mean duration, 80 weeks with tenofovir and 111 weeks with entecavir), more patients in the tenofovir versus the entecavir group had an eGFR <60 mL/min (15 vs. 6; P=0.022) and required medication dose adjustment (13 vs. 4; P=0.021). However, more patients in the entecavir versus the tenofovir group developed a SCr 2.5 mg/dL (6 vs. 1; P=0.053). Of note, in multivariate analysis, therapy assignment was not associated with an increase in SCr of 0.2 mg/dL or in eGFR <60 mL/min. Only history of organ transplant and preexisting renal insufficiency were associated with an increase in SCr of 0.2 mg/dL.

Comment: Renal adverse events were similar in patients receiving either tenofovir or entecavir for treatment of HBV infection. These findings are similar to those of long-term safety studies for both agents based on the treatment cohorts in their phase III registration trials. Clinicians should keep in mind that other patient factors, such as preexisting renal insufficiency, also increase the risk for renal adverse events.

Source: Journal Watch Gastroenterology

 

Medicare’s Efficiency Measure for Head CT for Atraumatic Headache Is Profoundly Flawed.

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A multicenter review of medical records shows that the measure is wildly unreliable, invalid, and inaccurate.

As part of their initiative to publically report and eventually pair reimbursement with specific quality and efficiency measures, the Centers for Medicare and Medicaid Services (CMS) developed an efficiency measure to evaluate use of brain computed tomography (CT) for emergency department (ED) patients who present with atraumatic headache. The measure (CMS OP-15) uses administrative billing data for patients with a final diagnosis of nonspecific headache. A CT scan is not included in the calculation (i.e., considered appropriate) if the patient has any of the following exclusions, which were derived based on guideline review and expert opinion: headache associated with lumbar puncture, dizziness, paresthesia, lack of coordination, subarachnoid hemorrhage, complicated or thunderclap headache, focal neurologic deficit, pregnancy, HIV, tumor or mass, or CT scan related to reason for admission. The National Quality Forum (NQF), which typically reviews and approves all measures for the CMS, rejected the proposed measure because it lacked scientific validity. The CMS implemented the measure despite the NQF finding.

These authors assessed the reliability, validity, and accuracy of the measure in a retrospective review of medical records for a convenience sample of 748 patients deemed by the CMS as having received inappropriate head CT because no exclusions were documented. The authors determined that exclusions were documented in the medical record for 489 patients (reliability, 35%) and that universally accepted indications for head CT (according to expert consensus, society guidelines, and literature) were present for 123 of 259 patients without exclusions documented in the medical record (validity, 48%). Overall accuracy of the measure was 17%.

Comment: CMS OP-15 should be immediately discontinued because it is fatally flawed: it was not validated with chart review and was implemented against the recommendation of the National Quality Forum, thus discrediting both organizations. Implementation of CMS OP-15 is unjustifiable and inexcusable and represents a complete abandonment of patient safety and quality of care in favor of thoughtless reduction of reimbursement for CT scans, which, according to national guidelines, are indicated and appropriate. In addition, implementation of this ill-conceived measure raises concerns about the ability of the CMS to police itself or anything else.

Source: Journal Watch Emergency Medicine

 

Underground Supermodels.

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What can a twentysomething naked mole-rat tell us about fighting pain, cancer, and aging?

Pitch dark, dank, and seething with saber-toothed, sausage-shaped creatures, the world of the African naked mole-rat is a hostile habitat. In the 1980s, scientists made the remarkable discovery that naked mole-rats live like termites with a single, dominant breeding queen and scores of nonbreeding adult helpers that never leave their natal colony. But the bizarreness doesn’t stop there. Naked mole-rats, unlike other mammals, tolerate variable body temperatures, attributed to their lack of an insulatory layer of fur. Their pink skin is hairless except for sparse, whisker-like strands that crisscross the body to form a sensitive sensory array that helps them navigate in the dark. Both the naked mole-rat’s skin and its upper respiratory tract are completely insensitive to chemical irritants such as acids and capsaicin, the spicy ingredient in chili peppers. Most surprisingly, they can survive periods of oxygen deprivation that would cause irreversible brain damage in other mammals, and they are also resistant to a broad spectrum of other stressors, such as the plant toxins and heavy metals found in the soils in which they live. Unlike other mammals, they never get cancer, and this maintenance of genomic integrity, even as elderly mole-rats, most likely contributes to their extraordinarily long life span. In contrast to similar-size mice that only live 2–4 years, naked mole-rats can survive and thrive, maintaining normal function and reproduction, into their 30s.

Brain tissue of naked mole-rats remains functional with no oxygen supply for more than three times as long as brain tissue of laboratory mice.

The current hypotheses for the existence of this suite of unusual features center around the equally unusual lifestyle traits of the naked mole-rat. (See illustration on page 33.) Naked mole-rats live in large family groups in elaborate underground burrows. Although they are protected from large temperature fluctuations as well as from predators and pathogens, they have to contend with low oxygen and high carbon dioxide levels, due to the large number of individuals—usually 100 to 300—living and respiring in close quarters under poorly ventilated conditions. The unusual ecology and social structure of the naked mole-rat make this an exciting system for understanding evolution and specialization, and details of the molecular mechanisms underlying the mole-rat’s unusually good health are providing insights into human disease.

No oxygen? No problem!

Most mammalian brains, including those of humans, start to suffer damage after just 3–4 minutes of oxygen deprivation. This is because brain tissue does not store much energy, and a steady supply of oxygen is needed to generate more. Hence, when the oxygen supply to the brain is reduced or blocked, brain cells run out of energy, and damage quickly ensues. This is a major concern for victims of heart attacks and strokes, in which the blood supply to the brain is interrupted. Brain tissue of naked mole-rats, on the other hand, remains functional with no oxygen supply for more than three times as long as brain tissue of laboratory mice. And when the oxygen level is restored, brain tissue from naked mole-rats frequently recovers fully, even after several minutes of inactivity.1

This remarkable ability no doubt stems from the challenge that all subterranean animals face: low oxygen levels because of poor air exchange with the surface. Oxygen depletion is even more pronounced for naked mole-rats because they live in large groups, with many individuals sharing the same poor air supply, and gas exchange is limited to diffusion or air turbulence caused by animals moving in the tunnels. So how do mole-rats survive in such smothering conditions?

Naked mole-rats display several physiological adaptations for survival in a low-oxygen environment. The hemoglobin in their red blood cells has a higher affinity for oxygen than that of most other mammals, meaning that their blood is better at capturing what little oxygen there is. They also have a greater number of red blood cells per unit volume. In addition, their mass-specific metabolic rate is only about 70 percent that of other rodents, so they use oxygen at a slower rate. But when it comes to the brain, naked mole-rats protect themselves by borrowing a strategy used by the brains of infants.

Infant mammals, including humans, are known to be much more tolerant of oxygen deprivation than older juveniles or adults. It turns out that calcium is a key factor in this tolerance. Normally, calcium ions in our brain cells play vital roles, including helping memories form. But it’s a delicate balance: small amounts of calcium are essential for brain function, but too much calcium makes things go haywire. When nerve cells are starved of oxygen, they no longer have the energy to regulate calcium entry, resulting in an influx of too much calcium, which poisons the cells. This is the primary cause of neuronal death during oxygen deprivation.

In the last decade or so, researchers discovered that adult and infant brains express different calcium channels in their cell membranes. Calcium channels in infants actually close during oxygen deprivation, protecting the brain cells from calcium overdose in the womb, where the baby gets much less oxygen. After the baby is born, however, oxygen is plentiful, and these channels are largely replaced by ones that open in response to oxygen deprivation, often leading to cell death.

Recent studies on naked mole-rats show that this species retains infant-style calcium channels into adulthood.2 Accordingly, calcium-imaging techniques show that oxygen deprivation leads to much less calcium entry into the brain cells of adult naked mole-rats compared to other adult mammals.3 These findings suggest a new strategy that may help human victims of heart attack and stroke: increase the numbers of infant-style calcium channels in the brain. Brain cells of adult humans actually have some of these channels already, just not enough to protect them during oxygen deprivation. If a drug is designed to quickly upregulate production of infant-style channels in the brains of heart attack and stroke victims, it could provide valuable protection during a time when a steady supply of oxygen-rich blood is not reaching the brain.

Digging the Underground Life

Naked mole-rats (Heterocephalus glaber) are rodents found in the hot tropical regions of the Horn of Africa. When he first described a naked mole-rat in 1842, the famous German naturalist Eduard Rüppell suspected he had encountered a diseased specimen—because the animal had no fur and permanently protruding teeth. Only after several more specimens had been collected did it become apparent that their weird appearance, variously described as resembling saber-toothed sausages or miniature walruses, was normal.

Naked mole-rats live in a maze of underground tunnels that may extend more than a mile in length and as deep as 8 feet beneath the soil surface. Their burrows contain both nest chambers, tended by sterile worker animals, and several toilets, which the animals use religiously to avoid contamination of their living space. To locate the roots, tubers, and small onion-like bulbs they eat, mole-rats must dig through the soil, expanding their tunnels using their chisel-like, ever-growing incisor teeth. They occasionally make an opening to the outside world to kick excavated soil to the surface, where it forms small volcano-shaped mounds—the only aboveground signs of the vast colonies below. Given this strictly subterranean existence, it is not surprising that naked mole-rats have evolved a set of characteristics highly suited to life in dark, dank burrows.

Feeling no pain

In addition to dealing with low oxygen levels, living in crowded underground burrows also means naked mole-rats must contend with high carbon dioxide (CO2) concentrations. In contrast to the typical atmospheric concentration of CO2 of about 0.03 percent, CO2 levels in naked mole-rat tunnels are closer to 2 percent, possibly reaching concentrations of 5 percent or more in their nest chambers. High levels of CO2 can be painful to the eyes and nose due to the formation of acid on the surface of those tissues—akin to the feeling of burping through one’s nose after drinking a carbonated beverage—but mole-rats are completely insensitive to this phenomenon. The skin and upper respiratory tract of naked mole-rats are also insensitive to other irritants, including other acids, ammonia, and capsaicin. Behaviorally, the animals show no signs of irritation or discomfort when a capsaicin solution is applied to their nostrils, whereas mice vigorously rub their noses after such exposure. Unlike rats and mice, naked mole-rats also fail to avoid strong ammonia fumes. When placed in an arena with sponges that are saturated with ammonia or water, mole-rats spend as much time in close proximity to the ammonia as they do to the water. The animals also show no response to capsaicin or acidic saline (like lemon juice) injected into the skin of the foot, while the same irritants cause rubbing and scratching at the injection site in humans and vigorous licking in rats and mice.

 

Recent experiments have shown that nerve fibers called C-fibers, which normally respond to high levels of CO2and other chemical irritants, are much less sensitive in naked mole-rats than in other mammals. These fibers are small in diameter, and release neuropeptides—notably Substance P and calcitonin gene-related peptide—onto targets in the central nervous system to convey a stinging or burning sensation. Importantly, the same C-fibers that respond to acid and capsaicin are responsible for the pain people experience minutes, hours, or even days after an injury.

Surprisingly, physiological studies revealed that naked mole-rat C-fibers innervating their eyes, nose, and skin do respond to capsaicin, but that the nerves do not make the neuropeptides usually released because of a defect in gene promoters associated with the pain-relaying nerve cells. While the animals express the neuropeptides in other parts of the body, such as the brain and intestines, lack of these neuropeptides from the C-fibers acts to “disconnect” the fibers from the central nervous system, preventing the feelings of pain and irritation. Sure enough, when researchers introduced one of the missing neuropeptides, Substance P, into the C-fibers of naked mole-rat feet using gene therapy, the animals licked at the injection site similarly to rats and mice.4

Insensitivity to acidic saline appears to be mediated by a different mechanism. In contrast to their response to capsaicin, C-fibers in naked mole-rats are completely unresponsive to acidic saline. A recent study revealed that acid insensitivity involves voltage-gated sodium channels, which are necessary to propagate signals along the nerve fibers.5 In naked mole-rats, these channels have a mutation that make them shut down under acidic conditions.

Naked mole-rat C-fibers also have an unusual pattern of connectivity in the spinal cord. Almost half of the cells in the deep dorsal horn of the spinal cord receive direct connections from C-fibers, whereas in other species, most C-fibers terminate in the superficial dorsal horn, at the outer edge of the spinal cord. The significance of this unusual connection pattern is not clear, but it suggests that whatever signals are conveyed from the C-fibers might not follow the usual pain and irritant pathways once they reach the spinal cord.

Interestingly, naked mole-rats respond normally to pinch and heat; only C fiber-mediated pain has been muted in these animals. A greater understanding of how this type of pain processing is altered in naked mole-rats could have significant implications for the treatment of chronic pain in humans, such as post-surgical, joint and muscle, and inflammatory pain.

Cancer schmancer

Unlike mice, which very commonly develop tumors, naked mole-rats have never been found to naturally have cancer. Moreover, subjecting mole-rats to ionizing radiation does not induce much DNA damage, as seen in other animals, nor does it result in tumors, even 5 years later. Attempts to turn naked mole-rat cells cancerous via injection of oncogenes have also failed, whereas similar methods using human, mouse, and even cattle cells results in conversion to highly aggressive and invasive cancer-forming cells.6 Instead of starting to proliferate in an uncontrolled manner, transformed naked mole-rat cells immediately stop dividing, though they do not die.7 Similarly, naked mole-rat cells treated with a toxin or simply housed under suboptimal conditions immediately stop dividing until conditions improve.

Unlike mice, which very commonly develop tumors, naked mole-rats have never been found to naturally have cancer.

This has led some scientists to suggest that naked mole-rat cells are claustrophobic in culture and stop dividing as soon as they touch other cells, and that this contact inhibition is a mechanism of cancer resistance. However, several different labs have now shown that naked mole-rat cells grow to even higher densities than do mouse cells under optimal conditions, and do not avoid cellular contact under these circumstances. Rather, it has become increasingly clear that naked mole-rat tissues are better able to recognize abnormal cells, neutralize their tumorigenic properties, and repair their DNA. Should that fail, the cells are ushered into programmed cell death pathways.

The recently sequenced genome of the naked mole-rat has afforded a number of novel insights into why naked mole-rats appear to be impervious to cancers.8 Many of the genes involved in the regulation of cell proliferation are positively selected for or have unique sequences that appear to result in the naked mole-rat’s unusual health. Similarly, many gene families in the mole-rat genome are involved in DNA repair and detoxification processes, and the expression of these genes remains unchanged as the animals age. Given that cancer is one of the largest contributors to mortality in elderly humans, sustained genomic maintenance and simultaneous invulnerability to cancer may contribute substantially to the exceptional longevity of naked mole-rats.

Naked mole-rats also have in place several mechanisms to ensure protein quality control and homeostasis. Their proteins appear to be very resistant to unfolding stressors such as high temperatures and urea, and the animals’ cells are particularly efficient at removing damaged proteins and organelles via the ubiquitin-proteasome system and autophagy. Indeed, naked mole-rat proteasomes are both more abundant and show greater efficiency in degrading stress-damaged proteins in liver tissue than do the proteasomes within liver tissues of laboratory mice.9 Similarly, autophagy occurs at a twofold greater rate in naked mole-rat cells than those of the mouse. Collectively, these enhanced intracellular cleaning processes may contribute to the better maintenance of a high-quality proteome and help the naked mole-rat’s cells resist damage in the face of cellular toxins, such as heavy metals or direct DNA-damaging agents. Much higher concentrations of these toxins are needed to kill naked mole-rat cells than are needed to kill mouse cells subjected to the identical experimental treatment.

Forever young

Although naked mole-rats are the size of a mouse, weighing only about 35–65 grams, in captivity these rodents live 9 times longer. With a recorded maximum lifespan of 32 years, they are the longest-lived rodents known.10 And remarkably, they appear able to maintain good health for most of their lives. At an age equivalent to a human age of 92 years, naked mole-rats show unchanged levels of activity and metabolic rate, as well as sustained muscle mass, fat mass, bone density, cardiac health, and neuron number. These clear indications of both attenuated and delayed physiological aging are also accompanied by the maintenance of protein quality and gene expression levels.

Some of the oldest naked mole-rats (>26 years; equivalent to humans >105 years old) do begin to show signs of muscle loss, osteoarthritis, and cardiac dysfunction, demonstrating that mole-rats do, eventually, age like other animals. Somehow they delay the onset of aging and compress the period of decline into a small fraction of their overall lifespan. These findings of sustained good health are surprising given that the naked mole-rat is an exception to many of the current theories of why we age. For example, the widely accepted oxidative stress theory of aging attributes the gradual decline in function to damage caused by the free radicals or reactive oxygen species formed as an inevitable by-product of oxygen respiration. In much the same way that oxygen causes metal to rust when exposed to the elements, cell membranes, proteins, and DNA are damaged by the gas, and this accumulating damage, so goes the theory, causes physiological systems to malfunction. Naked mole-rats in captivity, however, show very high levels of oxidative damage at an early age, yet cellular function is not impaired, and the animals are able to tolerate these high levels of oxidative damage for more than 20 years.

Another aging theory posits that the length of an organism’s telomeres, the repetitive DNA that caps the ends of chromosomes, is a biomarker of aging and will correlate with species’ life span. But compared to the much shorter-lived laboratory mouse, the naked mole-rat has relatively short telomeres—similar in length to those of humans, in fact. Alternatively, cellular levels of telomerase, a reverse transcriptase enzyme that extends telomeres, may correlate with species longevity. But while telomerase activity has been measured in mole-rat skin cells in culture, it is generally very low, and is limited to those tissues that are actively replicating, such as testes, spleen, and skin. Thus, telomere length or maintenance is unlikely to explain the exceptional longevity of the naked mole-rat.

Clearly, studies involving this bizarre-looking but fascinating animal have highlighted many key facets of their unusual biology that are directly relevant to biomedical research. Indeed, these studies have yielded critical information regarding how the brain works, and how animals respond to the lack of oxygen and of light, as well as how we might learn to slow down aging, prevent cancer, and mitigate inflammatory pain and the harmful effects that occur when oxygen delivery is impaired. It will be exciting to be a part of the continued research on these incredible creatures that is likely to reveal novel drug targets for a variety of human ailments.

Thomas Park is a professor of biological sciences and neuroscience at the University of Illinois at Chicago. Rochelle Buffenstein is a professor of physiology at the Barshop Institute for Longevity and Aging Studies and the University of Texas Health Science Center in San Antonio, Texas.

References

  1. J. Larson, T.J. Park, “Extreme hypoxia tolerance of naked mole-rat brain,” NeuroReport, 20:1634-37, 2009. ↩
  2. B.L. Peterson et al., “Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals,” Neurosci Lett, 506:342-45, 2012. ↩
  3. B.L. Peterson et al., “Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus,” PLoS One, 7:e31568, 2012. ↩
  4. T.J. Park et al., “Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber),” PLoS Biol, 6:e13, 2008. ↩
  5. E.S. Smith et al., “The molecular basis of acid insensitivity in the African naked mole-rat,” Science, 334:1557-60, 2011. ↩
  6. S. Liang et al., “Resistance to experimental tumorigenesis in cells of a long-lived mammal, the naked mole-rat (Heterocephalus glaber),” Aging Cell, 9:626-35, 2010. ↩
  7. K.N. Lewis et al., “Stress resistance in the naked mole-rat: the bare essentials,” Gerontology, in press, doi:10.1159/000335966, 2012. ↩
  8. E.B. Kim et al., “Genome sequencing reveals insights into physiology and longevity of the naked mole rat,” Nature, 479:223-27, 2011. ↩
  9. K.A. Rodriguez et al., “Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat,” PLoS ONE, 7:e35890, 2012. ↩
  10. R. Buffenstein, “Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species,” J Comp Physiol B, 178:439-45, 2008. ↩

Source: the scientist

 

What exactly are GMOs and why should they be labeled?

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GMOs (genetically modified organisms) were brought into the world by a chemical company, not an agriculture or food group. Monsanto created DDT, PCBs, Agent Orange, marketed aspartame, and created bovine growth hormone (rBGH) to infect milking cows that put pus into commercial milk.

GMOs are created within the seeds of chosen parent crops in laboratories by “splicing” genes from completely unrelated species into those seeds. Normal plant hybrids are cultivated in soil over time by cross pollinating closely related plants.

So far, GMOs have invaded soy, corn, beets (for beet sugar), cotton, and alfalfa agriculture. Many GMO edibles are contained surreptitiously in a wide variety of processed foods, while GMO corn and soy are used by unnatural factory farm feed lots.

If you’ve been following NaturalNews for some time, you may recall several articles describing GMOs’ inherent human and animal health hazards as well as crop and environmental dangers. If not, you’ll find most of them here. (http://www.naturalnews.com/GMO.html)

GMOs damage crops, the environment, and the food chain

GMOs are often genetically created artificially to tolerate herbicides, made by Monsanto and others, that kill weeds. The herbicides contain glyphosates. Monsanto’s Roundup weed killer is meant for Roundup Ready GMO crop seeds. It’s an extremely toxic glyphosate agent.

Glyphosates greatly harm grazing animals and pollute the wells and groundwater of farm areas where they’re used. (http://naturalsociety.com)

They create sterility and birth defects among animals and humans. Most of the honey bee die-off, or colony collapse, is attributed to glyphosates. If enough pollinating bees disappear, our food chain is endangered further.

Glophosate’s chelating capabilities remove minerals from the soil where they’re sprayed. So crops get increasingly worse while increasingly abundant Roundup resistant weeds, or super weeds, force farmers to add more toxic materials to Roundup.

It’s a vicious cycle for farmers who, conned by greater production promises, unwittingly signed on to Monsanto Roundup Ready GMO binding seed contracts. Monsanto uses patent laws to litigate against farmers whose non-GMO fields are contaminated by GMO fields, forcing smaller farms out of business.

Most farmers fold because they cannot afford the litigation. American farmers are attempting to organize against mostly Monsanto’s GMOs. European farmers have managed to resist thus far.

Why you should be concerned

Maybe the reasons summarized above are too abstract. So let’s get personal. Contrary to mainstream media’s (MSM) outlook, the jury is not out on GMOs. GMOs do destroy human and animal health while endangering non-GMO crops with contamination. That’s been discovered by several scientists acting independently.

They jeopardize their careers and even their lives by communicating what they find while the MSM ignores them. Anti-GMO activist and author Jeffrey Smith lists the casualties and summarizes Monsanto’s harassment here: (http://www.sott.net)

Agro-ecologist Don Lotter, Ph.D. released an inside scoop when he stated:

The promoter gene used … [the] cauliflower mosaic virus, … [was assumed to be] denatured in our digestive system, but it’s not. It has been shown to promote the transfer of transgenes from GM foods to the bacteria within our digestive system, which are responsible for 80 percent of our immune system function.

Read Lotter’s interview here: (http://www.organicconsumers.org/articles/article_19468.cfm)

This from Wessex Natural Law research papers: The cauliflower mosaic virus (CaMV 35S) used for plant genetic engineering is cited as a source of viral recombination as well as a gene silencer and DNA disruptor.

Forget petitioning the government. It’s so corrupted that one of Monsanto’s most ruthless executives, Michael Taylor, now serves in the Obama administration as FDA chief adviser, or “Food Czar.”

That’s why our only chance is to help California succeed with Proposition 37. GMO labeling may spill over from California making it easier to boycott GMOs. (http://www.kcet.org)

Sources:

http://www.youtube.com/watch?v=Lni6OAJz3sk&feature=player_profilepage

http://www.naturalnews.com/031825_GMOs_threat.html

http://www.organicconsumers.org/articles/article_19468.cfm

http://rense.com/general33/fd.htm

http://www.gene.ch/info4action/2000/Feb/msg00028.html

http://www.naturalnews.com/033804_Scientists_Under_Attack_GMOs.html

INTERNATIONAL PEACE DAY.

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