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Five superbug defenses that can keep you from dying in the hospital

December 22, 2010 Leave a comment

By Boonsri Dickinson | Dec 22, 2010 | 0 Comments

He may have not realized it, but Alexander Fleming accidentally discovered a mold that could save millions of lives. On 1928, while in his lab, he discovered penicillin. The active ingredient in the mold Penicillium notatum was an infection-fighting agent that could kill colonies of the bacterium Staphylococcus aureus.

The pharmaceutical industry began producing antibiotics, drugs that could kill disease-causing bacteria. Bye bye, syphilis? Bye bye, gangrene? Bye bye, tuberculosis? Almost. Doctors started prescribing them (and then over-prescribing them). And we started using them (and abusing them).

However, this spawned another problem. This one possibly was as lethal as the infection itself: resistance and the suberbug. Some experts warn that we are at the end of the antibiotic era.

University of California, Los Angeles professor Brad Spellberg told Newsweek:

“It’s already happening,” says Spellberg, to the tune of roughly 100,000 deaths a year from antibiotic-resistant infections in the United States alone. “But it’s going to become much more common.”

Methicillin-resistant Staphylococcus aureus, or MRSA is a superbug – when it enters the blood stream and begins to attack the body, the infection can grow so large only surgery can get rid of the drug-resistant bug.

Right now, our best line of defense to kill off the infection is antibiotics. Sometimes, as a last line of defense, doctors prescribe — vancomycin and linezolid. But even those drugs aren’t guaranteed to work.

The MRSA infections are becoming a problem as bacteria become resistant to antibiotics. Just because hospital-acquired MRSA infections have been declining, it doesn’t mean we don’t need more ways to fight the superbug infections.

Superbugs are a huge problem in hospitals, but scientists have been working on a number of ways to combat the spread of the potentially deadly bug.

Here are five technologies that stand a chance against superbugs:

1. Fecal transplants: Any poo will suffice, as long as it is screened for infectious diseases. But siblings make the best donors. Gastroenterologist Thomas Borody’s clinic has performed 1,500 fecal transplants. Restoring the bacterial flora of the colon to the native state can literally stop a potentially deadly Clostridium difficile infection from taking over.

Borody tells New Scientist:

“I got a very bad name among my colleagues, as someone who feeds people shit.”

The donor’s poo is first cleaned with saline and filtered to remove unwanted particles. Then the poo is fed to a patient through a tube goes through the nose and into the stomach. Going from the bottom seems the more natural way. Either way, the transplants help restore populations of Bacteroides, the type of bacteria that is seen in a person with a healthy colon.

Borody asks:

“We have a therapy that is nearly 100 per cent curative. What the hell are we doing spending millions of dollars on antibiotics?”

2. Light technology: Scientists at the University of Strathclyde have shown that special light can make bacteria basically commit cell suicide. Clinical trials proved the HINS-light Environmental Decontamination System is effective in getting rid of bacterial pathogens in the hospital setting. The light prevents the pathogens from being transmitted through the environment – which ultimately prevents the spread of the infection among patients. University of Strathcylde professor John Anderson explains:

“The system works by using a narrow spectrum of visible-light wavelengths to excite molecules contained within bacteria. This in turn produces highly reactive chemical species that are lethal to bacteria such as meticillin-resistant Staphylococcus aureus, or MRSA, and Clostridium difficile, known as C.diff.”

3. Anti-pathogenic drugs: Case Western Reserve researchers developed an anti-pathogenic drug to treat MRSA . The drug works by blocking MRSA from producing toxins. This way, you can treat MRSA without actually killing the bacteria.

“Staph bacteria are ubiquitous and normally do not cause infections, however, occasionally these bacteria become harmful due to their secretion of toxins,” said Case Western Reserve’s professor Menachem Shoham. The key was preventing a molecule called AgrA from releasing toxins. The professor looked for compounds to inhibit it, so he screened 90,000 compounds. Seven of those worked.

The anti-pathogenic drugs might change they way we fight bacteria in the body. The way we currently treat the infection makes it a prime place for bacteria to want to fight for survival. The side effect of that is the eventual resistance to the drugs. This new type of drug would sidestep that urge and keep the bacteria at bay.

4. Brains of cockroaches: My first instinct around cockroaches have been to kill them with a paper towel. British researchers discovered that molecules found inside the brain tissues of insects can fended off unwanted bacteria. The brain tissue killed off 90 percent of the E. coli and MRSA. Remarkably, the healthy human cells were left alone.

“We hope that these molecules could eventually be developed into treatments for E. coli and Meticillin-resistant Staphylococcus aureus infections that are increasingly resistant to current drugs,” University of Nottingham’s Simon Lee said in a statement. “Also, these new antibiotics could potentially provide alternatives to currently available drugs that may be effective but have serious and unwanted side effects.”

5. A coating can kill MRSA upon contact: Imagine if surgical equipment or the walls of the hospital could be coated with a paint that could slice up MRSA. The coating has carbon nanotubes with lysostaphin, an enzyme that is found in Staph bacteria that naturally fights off the superbug.

In the lab, when the nanotube-enzyme was mixed with regular household paint, all of the MRSA was eradicated in 20 minutes after it touched the special surface. Don’t worry though, the paint isn’t toxic to other cells – it’s just toxic to MRSA. It probably won’t lead to more resistance and won’t pollute the environment. The coating can be washed without losing its ability to kill MRSA.

Related on SmartPlanet:

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Categories: Health, Medical

Alzheimer’s study finds HDL good for brain, too

December 14, 2010 Leave a comment

CHICAGO (Reuters) – In addition to being good for the heart, high levels of so-called “good” cholesterol may protect against Alzheimer’s disease, U.S. researchers said on Monday.

They found people over 65 who had the highest levels of high-density lipoprotein or HDL were 60 percent less likely to develop Alzheimer’s disease over four years than people with the lowest HDL levels.

And it did not seem to matter if people had high HDL levels naturally or if they took widely used drugs called statins to increase “good” cholesterol levels, the researchers found.

The study points to a potential means of preventing Alzheimer’s, an incurable brain-wasting disease that affects 26 million people globally and costs $604 billion to treat.

By raising HDL, “you can probably lower the frequency of Alzheimer’s disease in the population,” said Dr. Christiane Reitz of Columbia University’s Taub Institute in New York, whose study appears in the Archives of Neurology.

Her team studied 1,130 people over 65 who were white, black or Hispanic and lived in New York City. Most were covered by Medicare, the federal insurance program for the elderly.

When they started the study, the volunteers had no history of memory or thinking problems. Over the course of the study, the team used medical and neurological data and did neuropsychological testing to diagnose Alzheimer’s disease.

They divided people into four groups, or quartiles, based on cholesterol readings. Those in the highest group had HDL readings of 55 or higher. Those in the lowest quartile had HDL below 38.

“The highest quartile compared to the lowest had a 60 percent lower risk of developing Alzheimer’s disease over four years,” Reitz said in a telephone interview.

Reitz said the team looked specifically at people with probable or possible Alzheimer’s disease, rather than vascular dementia or other forms of dementia.

They also looked at other cholesterol measures, such as total cholesterol, LDL and blood fats known as triglycerides.

“We looked at each of those measures independently. It seems to be an isolated effect for HDL,” Reitz said.

An HDL reading of 60 or higher is considered protective against heart disease, according to the American Heart Association.

Reitz said an HDL reading of 55 or greater is achievable by changing diets and exercising. Some doctors also prescribe niacin, a B vitamin that can boost heart-protective HDL 25 percent, but this is not widely used because it causes uncomfortable facial flushing.

A new class of HDL-raising drugs called CETP inhibitors, such as Merck’s experimental drug anacetrapib, are showing promise at significantly raising good HDL cholesterol.

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Categories: Health, Medical

Review of the TSA X-ray backscatter body scanner safety report: hide your kids, hide your wife

November 29, 2010 Leave a comment

I am a biochemist working in the field of biophysics. Specifically, the lab I work in (as well as many others) has spent the better part of the last decade working on the molecular mechanism of how mutations in the breast cancer susceptibility gene, BRCA2, result in cancer.
 
The result of that work is that we now better understand that people who have a deficient BRCA2 gene are hypersensitive to DNA damage, which can be caused by a number of factors including: UV exposure, oxidative stress, improper chromosomal replication and segregation, and radiation exposure. The image below shows what happens to a chromosome of a normal cell when it is exposed to radiation.
 
It most cases, this damage is repaired; however, at high doses or when there is a genetic defect, the cells either die or become cancerous.
 
Quite some time ago, I posted a short educational video that describes how BRCA1 and BRCA2 mutations cause cancer. In short, when a person who has a mutation in one of these genes is exposed to environmental factors that cause DNA damage, they simply don’t repair the damage with the same efficiency as the general population.

 

Over the course of their lifetime, the incremental exposures to relative small and seemingly safe doses of ionizing radiation (which is everything from UV light to X-rays to gamma radiation) statistically accumulate damage (or the effects of damage and improper repair) until the probability of developing cancer becomes almost certain.

 

This is because BRCA1 and BRCA2 are both part of a molecular process that is very similar to the spell-check on your word processor (in oncology parlance, these genes are known as caretakers of the genome for this specific reason). When these genes don’t work, mutations accumulate faster and eventually results in cancer. 

Its because of my interest in this aspect of cancer biology that I felt compelled to review the safety reports released on the TSA website here. However, my interest is not only professional, but also personal. My grandmother died of breast cancer in 2005 after being in remission for 20+ years. While she was never tested for either BRCA1 or BRCA2, her family history indicates that there is a strong probability of one of these mutations running in my family.

 

Including my grandmother, at least four of her siblings developed cancer: two died of breast cancer, one developed a rare form of leukemia and another died of skin cancer.

 

All of her female siblings had cancer, and its noteworthy that her mother died of a very young age (maybe 30’s or early 40’s) of an unknown (to me) cause. For these reasons, I fear that inadequate safety evaluation of these machines could unduly expose my family (and myself) to levels of radiation that might be harmful should this high familial cancer rate in fact be hereditary.

Last spring, a group of scientists at the University of California at San Francisco (UCSF) including John Sedat Ph.D., David Agard Ph.D., Robert Stroud, Ph.D. and Marc Shuman, M.D. sent a letter of concern to the TSA regarding the implementation of their ‘Advanced Imaging Technology’, or body scanners as a routine method of security screening in US airports. Of specific concern is the scanner that uses X-ray back-scattering. In the letter they raise some interesting points, which I’ve quoted below:

 
  • “Our overriding concern is the extent to which the safety of this scanning device has been adequately demonstrated. This can only be determined by a meeting of an impartial panel of experts that would include medical physicists and radiation biologists at which all of the available relevant data is reviewed.”
  •  
  • “The X-ray dose from these devices has often been compared in the media to the cosmic ray exposure inherent to airplane travel or that of a chest X-ray. However, this comparison is very misleading: both the air travel cosmic ray exposure and chest X-rays have much higher X-ray energies and the health consequences are appropriately understood in terms of the whole body volume dose. In contrast, these new airport scanners are largely depositing their energy into the skin and immediately adjacent tissue, and since this is such a small fraction of body weight/vol, possibly by one to two orders of magnitude, the real dose to the skin is now high.
  •  
  • “In addition, it appears that real independent safety data do not exist.”
  •  
  • “There is good reason to believe that these scanners will increase the risk of cancer to children and other vulnerable populations. We are unanimous in believing that the potential health consequences need to be rigorously studied before these scanners are adopted.”
 

In order to really understand these concerns, I think its important to consider the type of radiation used in these scanners, which the TSA has described as ‘soft’ and ‘safe’. First, we need to clarify the definition of ‘soft’ vs ‘hard’ X-rays. The TSA has been stating that the X-rays used in the back scatter machines use ‘soft’ X-rays, which are defined as radiation between 0.12-12 keV (or kilo electron volts) and are generally stopped, or absorbed, by soft tissue or low density matter. ‘Hard’ X-rays are between 12-128 keV and are absorbed by dense matter like bone. According to the TSA safety documents, AIT uses an 50 keV source that emits a broad spectra (see adjacent graph from here). Essentially, this means that the X-ray source used in the Rapiscan system is the same as those used for mammograms and some dental X-rays, and uses BOTH ‘soft’ and ‘hard’ X-rays. Its very disturbing that the TSA has been misleading on this point. Here is the real catch: the softer the X-ray, the more its absorbed by the body, and the higher the biologically relevant dose! This means, that this radiation is potentially worse than an a higher energy medical chest X-ray.

With that being said, because the scanners have both a radiation source AND a detector in the front AND back of the person in the scanner, it is actually possible for the hardware to conduct a classic, through-the-body X-ray. The TSA claims that the machines are not currently being used in that way; however, based on the limited engineering schematics released in the safety documents, they could be certainly be easily reconfigured to do so by altering the aluminum-plate (or equivalent) filter or by changing the software. So the hardware has the capability to output quite high doses of radiation, however a biological dose is a function of the time of exposure as well as the proximity to the source and the power of the power of the source.

Unfortunately, it is difficult to determine which zones in the scanner are ‘hottest’ because that information is masked in the document. An excerpt of the safety evaluation from Johns Hopkins is shown below to give you sense of how much other information is being withheld. Ultimately my point is this: even though the dose may actually be low, these machines are capable of much higher radiation output through device failure or both unauthorized or authorized reconfiguration of either hardware or software.


Which brings me to how the scanner works. Essentially, it appears that an X-ray beam is rastered across the body, which highlights the importance of one of the specific concerns raised by the UCSF scientists… what happens if the machine fails, or gets stuck, during a raster. How much radiation would a person’s eye, hand, testicle, stomach, etc be exposed to during such a failure. What is the failure rate of these machines? What is the failure rate in an operational environment? Who services the machine?

What is the decay rate of the filter? What is the decay rate of the shielding material? What is the variability in the power of the X-ray source during the manufacturing process? This last question may seem trivial; however, the Johns Hopkins Applied Physics Laboratory noted significant differences in their test models, which were supposed to be precisely up to spec. Its also interesting to note that the Johns Hopkins Applied Physics Laboratory criticized other reports from NIST (the National Institute of Standards and Technology) and a group called Medical and Health Physics Consulting for testing the machine while one of the two X-ray sources was disabled (citations at the bottom of the page).

These questions have not been answered to any satisfaction and the UCSF scientists, all esteemed in their fields and members of the National Academy of Sciences have been dismissed based on a couple of reports seemingly hastily put together by mid-level government lab technicians. The documents that I have reviewed thus far either have NO AUTHOR CREDITS or are NOT authored by anyone with either a Ph.D. or a M.D., raising serious concerns of the extent of the expertise of the individuals and organizations evaluating these machines. Yet, the FDA and TSA continue to dismiss some of the most talented scientists in the country…

With respect to errors in the safety reports and/or misleading information about them, the statement that one scan is equivalent to 2-3 minutes of your flight is VERY misleading. Most cosmic radiation is composed of high energy particles that passes right through our body, the plane and even most of the earth itself without being absorbed or even detected. The spectrum that is dangerous is known as ionizing radiation and most of that is absorbed by the hull of the airplane. So relating non-absorbing cosmic radiation to tissue absorbing man-made radiation is simply misleading and wrong.

Furthermore, when making this comparison, the TSA and FDA are calculating that the dose is absorbed throughout the body. According the simulations performed by NIST, the relative absorption of the radiation is ~20-35-fold higher in the skin, breast, testes and thymus than the brain, or 7-12-fold higher than bone marrow. So a total body dose is misleading, because there is differential absorption in some tissues. Of particular concern is radiation exposure to the testes, which could result in infertility or birth defects, and breasts for women who might carry a BRCA1 or BRCA2 mutation.

Even more alarming is that because the radiation energy is the same for all adults, children or infants, the relative absorbed dose is twice as high for small children and infants because they have a smaller body mass (both total and tissue specific) to distribute the dose. Alarmingly, the radiation dose to an infant’s testes and skeleton is 60-fold higher than the absorbed dose to an adult brain!

There also appears to be unit conversion error in the Appendix of the report, which was recently cited by the FDA in response to the UCSF scientist’s letter of concern, which might mean that the relative skin dose is 1000-fold higher than the report indicates (pg Appendix B, pg ii, units of microSv are used in an example calculation, when it appears that units of milliSv should have been used). I attempted to contact the author, Frank Cerra, to query whether this was a computational mistake or an unexplained conversion; however, none of his web-published email addresses are valid and there was no answer by phone. I cannot rule out that a conversion factor was used that was not described in the methods, and would welcome confirmation or rebuttal of this observation.

Finally, I would like to comment on the safety of the TSA officers (TSO) who will be operating these machines, and will be constant ‘bystanders’ with respect to the radiation exposure. The range of exposure estimates is a function of where an officer stands during their duty, what percentage of that duty is spent in the same location and how often the machine is running. A TSO could be exposed to as much as 86-1408 mrem per year (assuming 8 hours per day, 40 hours a week, 50 weeks per year and between 30-100% duty and 25-100% occupancy, as defined by the Johns Hopkins report), which is between 86%-1410% of the safe exposure of 100 mrem.

At the high end, if for example a TSO is standing at the entrance of the scanner when it is running at maximum capacity, then that officer could hit their radiation exposure limit in as few as 20 working days (assuming an 8 hour shift). While we may not be very happy with our TSOs at the moment as the face of these policies, we need to keep in mind that they really should be wearing radiation badges in order to know their specific exposure (especially for those officers who may also have to receive radiation exposure for medical reasons).

As far as I’m concerned, the jury is still out on whether these machines are safe or even could be made safe for this application. Until then, I suggest keeping your family out of these machines and as vile as it is, either submit to a physical search or just don’t fly.

Safety reports that should be considered invalid due to the fact that one of the two X-ray sources was disabled during testing:

  1. Medical and Health Physics Consulting, Radiation Report on Rapiscan Systems Secure 1000 (March 21, 2006).
  2. Medical and Health Physics Consulting, Radiation Report on Rapiscan Systems Secure 1000 (June 5, 2008).
  3. Medical and Health Physics Consulting, Supplement to Report dated June 5, 2008 (October 28, 2008).
  4. National Institute of Standards and Technology Assessment of Radiation Safety and Compliance with ANSI N43.17-2002 Rapiscan Dual Secure 1000 Personnel Scanner (July 9, 2008).
UPDATE 

Just to clarify, I am not a radiation biologist, radiologist, health physicist, etc… my expertise is actually in single molecule biophysics and the biochemistry of DNA repair. This article is simply my review of the safety reports published by the TSA on their website, and not the result of any independent evaluation or experimentation. Also, all views and comments are my opinion (professional and unprofessional) and are not endorsed or representative of the University of California or any affiliated departments or colleges.

Source article

Posted by Jason

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Categories: Medical, Tech

Studies push daily meds for colon health

November 21, 2010 1 comment

An aspirin a day won’t keep any doctors away–but researchers still want you to think otherwise.

The latest pill-pushing nonsense is a study that claims a daily “baby” aspirin can lower your risk of colon cancer.

But before you invest in that club-sized pill bottle, let’s take a closer look at the details of the study in The Lancet–because it’s not exactly the kind of research you want to base your health decisions on.

Researchers looked at two decades of data from four clinical trials involving more than 14,000 patients, and found that daily aspirin at any dose–even the low-dose “baby” aspirin–reduced colon cancer risk by 24 percent, and lowered the risk of dying from the disease by 35 percent.

That sounds impressive until you realize that the trials were designed to measure stroke risk, not colon health.

In addition, the trials in the analysis were all conducted before colonoscopies reached widespread use, so the researchers say they have no idea if regular screenings would negate the “benefits” of daily aspirin.

In reality, the idea of daily aspirin for various conditions has come up repeatedly over the years, and is usually discredited later on.

Many doctors still push “aspirin therapy” for its supposed heart benefits, but that’s just one more modern medical myth: Studies have repeatedly proven that aspirin won’t lower your heart risk–but it will increase the odds of painful ulcers and gastrointestinal bleeding. (Click here to read more.)

And that’s not the only bad advice on colorectal health out this week–because another new study is pushing statins as a means of lowering colon cancer risk.

Researchers analyzed 20 studies involving more than 2.5 million patients, and found that those who took statins were 12 percent less likely to develop colorectal cancer than those who didn’t take these cholesterol-lowering meds.

And if you want to believe that one, I can show you a study earlier this year that found statins not only DON’T reduce the risk of colon cancer, but can actually increase the risk of precancerous polyps.

Like aspirin, far too many people are already taking statins every day for all the wrong reasons. And like aspirin, statins come with a long list of ugly risks. Statins have been linked to muscle pain and permanent muscle damage, liver and kidney problems and even cataracts.

And–again, just like aspirin–statins are completely unnecessary for colon health. If you want to protect yourself from this deadly cancer, all you really need are regular colonoscopies and old-fashioned good habits.

One new study even finds that five healthy habits can erase nearly 25 percent of all colon cancers: Don’t smoke, keep your drinking moderate, get moving for half an hour a day, eat right and don’t let your waistline get too big.

For that last one, they recommend no bigger than 34.6 inches for women and 40.1 inches for men, which isn’t exactly a demand that we turn into stick figures.

What’s more, the researchers wrote in BMJ that taking on just one of those healthy habits will lower your risk by 13 percent.

Other studies have found that you can lower colon risk by limiting the amount of processed meat in your diet, dramatically cutting back on refined carbohydrates (especially sugar) and drinking several cups of coffee a day.

That sounds a lot easier–and far safer–than daily painkillers or statins.
On a mission for your health,

Ed Martin
Editor, House Calls

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Scientists reveal surgical procedure for hard to cure hypertension

November 18, 2010 1 comment

Jewish World Review

By Thomas H. Maugh II


The drop in blood pressure was so profound that in 39 percent of the treated patients, it fell below 140/90

http://www.JewishWorldReview.com | (MCT) A simple surgical procedure destroying certain nerves in the kidney can sharply reduce blood pressure in patients whose hypertension cannot be controlled with conventional medications, researchers said Wednesday.

The study was conducted on 52 patients whose blood pressure averaged 178/96, despite the fact that they were taking five separate hypertension medications. On average, their pressures dropped by 32/12, while a control group of 54 patients receiving only drugs showed no changes.

“Those blood pressure reductions are pretty remarkable,” said Dr. Douglas Weaver, division head of cardiovascular medicine at the Henry Ford Health System in Detroit, who was not involved in the study. “Those patients had been given everything and had not responded. … Did they prove that this (should go into the clinic)? No, the study is far too small. But they have shown that here is a way we could potentially lower blood pressure.”

Dr. Suzanne Oparil, a hypertension specialist at the University of Alabama who was also not involved in the research, noted that “This is an extremely important study. We did work in the 1980s that showed that this prevents hypertension in animals, but had no way of translating it into humans. There is an enormous clinical need for this kind of approach.”

An estimated 75 million Americans have high blood pressure, defined as a pressure of 140/90 millimeters of mercury or higher. Anything between 120/80 and 140/90 is considered borderline high. High blood pressure is one of the leading causes of heart disease and stroke.

Some studies have shown that reducing the systolic blood pressure (the top number) by only 6 millimeters of mercury can reduce the relative risk of stroke by 35 to 40 percent and the relative risk of a heart attack by 20 to 25 percent.


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But an estimated 15 percent of those with high blood pressure are unable to control it, despite taking three or more medications. It is those people at whom the new treatment is aimed.

Researchers have known for decades that the sympathetic nervous system, which plays a role in the body’s “flight or fight” response, helps regulate blood pressure. Early attempts to control it with surgery produced severe side effects, and the efforts were abandoned when the first good anti-hypertensive drugs became available.

More recently, Ardian Inc. of Mountain View, Calif., has developed a system in which a small catheter is threaded through the groin and to the kidney, where radiofrequency energy is used to destroy the right nerves more precisely.

Dr. Murray D. Esler of the Baker IDI Heart and Diabetes Institute in Melbourne, Australia, led a trial of the device. The results were reported at a Chicago meeting of the American Heart Association and online in the journal Lancet.

The researchers found that only five of the 52 patients in the study did not respond to the treatment. For the rest, the mean systolic blood pressure after treatment was 146, and for 39 percnet of the patients, it dropped below 140, Esler said. The patients are still taking drugs, but some have been able to reduce their doses.

The patients have so far been followed only for six months. But Esler noted that some people in an earlier trial of the same procedure have now been followed for as long as 2 1/2 years and that their blood pressure has not gone back up.

The team found no acute damage from the surgery and no significant side-effects, he said.

The procedure takes about 40 to 60 minutes and will most likely cost about $10,000, according to the company. An overnight hospital stay will probably be necessary.

Ardian has been in discussions with the Food and Drug Administration, the company said, and will probably begin a larger trial of the procedure in the U.S. next year.

For his part, Esler envisions future trials on patients with less severe hypertension in which the treatment would result in a cure, not just improvement. “We’re slowly moving toward that, but to cure hypertension is probably still a dream,” he said.


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Myth of a germ-free world: a closer look at antimicrobial products

November 13, 2010 Leave a comment

D037-1iCampylobacter bacteria, a leading cause of bacterial foodborne disease.

Killing microorganisms has become a national obsession. A pair of antimicrobial compounds known as triclosan and triclocarban are lately the weapons of choice in our war of attrition against the microbial world. Both chemicals are found in an array of personal care products like antimicrobial soaps, and triclosan also is formulated into everyday items ranging from plastics and toys to articles of clothing.

But are these antimicrobial chemicals, as commonly used by people across the nation, really safe for human health and the environment? More pointedly, do they even work? According to associate professor Rolf Halden, of the Biodesign Institute at Arizona State University, the answer to these questions is an emphatic “No.”

A biologist and engineer, Halden is interested in chemicals produced in high volume for consumer use. “I follow the pathways of these substances and try to figure out what they do to the environment, what they do to us and how we can better manage them.”

The antimicrobial triclosan was patented in 1964, and began its use in clinical settings, where it was found to be a potent bacterial killer, useful before surgical procedures. Since then, industry’s drive to convince consumers of the need for antimicrobials has been aggressive and highly effective. Antimicrobials made their first appearance in commercial hand soaps in the 1980s and by 2001, 76 percent of liquid hand soaps contained the chemical.

Antimicrobials have become a billion dollar a year industry and these chemicals now pervade the environment and our bodies. Levels of triclosan in humans have increased by an average of 50 percent since 2004, according to newly updated data from the Centers for Disease Control and Prevention (CDC).Triclosan and triclocarban are present in 60 percent of all rivers and streams nationwide and analysis of lake sediments have shown a steady increase in triclosan since the 1960s. Antimicrobial chemicals appear in household dust where they may act as allergens, and alarmingly, 97 percent of all U.S. women show detectable levels of triclosan in their breast milk. Such unnecessary exposures carry risks which, at present, are ill-defined.

Halden and his team conducted a series of experiments aimed at tracking the environmental course of the active ingredients in personal care products. The disturbing results of their research indicate that triclosan and triclocarban first aggregate in wastewater sludge and are transferred to soils and natural water environments, where they were observed to persist for months or years.

The chemistry behind these compounds, which contain benzene ring structures that have been chlorinated, make them notoriously difficult to break down. Further, they are averse to water or hydrophobic, tending to stick to particles, which decreases their availability for breakdown processes and facilitates long-range transport in water and air. A recent study demonstrated the accumulation of triclosan in dolphins from contaminated coastal waters.

Earlier, the EPA had been provided with industry-funded studies of wastewater treatment plant effluent, seemingly indicating elimination of triclosan and triclocarban during the treatment process. But Halden speculated that these chemicals might in fact persist in the solid byproduct left over after treatment—the sewage sludge. The group’s suspicions were confirmed through an initial testing of a large wastewater treatment plant serving 1.3 million people, located in the Mid Atlantic region of the U.S.

In the first study of its kind, conducted by the team in 2006, it was determined that three quarters of the mass of triclocarban entering the wastewater treatment facility was simply moved from the water into the sludge. Similar tests confirmed the accumulation of triclosan in sludge with 50 percent efficiency.

“We make 13 billion pounds of dry sludge per year,” Halden notes. “That is equal to a railroad train filled with sludge stretching 750 miles from Phoenix to San Francisco.” One half of this sludge winds up on agricultural fields. The potential for these chemicals to migrate into food or leach into groundwater, has not received adequate consideration. It is likely that antimicrobials are capable of moving up the food chain, through a process known as biomagnification.

Both triclosan and triclocarban have been linked to endocrine disruption, with potential adverse impacts on sexual and neurological development. Further, the accumulation of these antimicrobials in the environment is exerting selective pressure on microorganisms exposed to them, thereby increasing the likelihood that a super-bug, resistant to the very antimicrobials developed to kill them, will emerge—with potentially dire consequences for human health.

On the positive side, Halden’s team identified specific microorganisms adapted to not only tolerate but also break down pervasive antimicrobials. The research is part of a wider effort aimed at alerting the public and regulatory agencies, including the EPA and FDA, of the dangers of these chemicals as well as developing effective remediation strategies.

As Halden explains, “these microbes have the dual advantage of being resistant to destruction by antimicrobials and being able to break down these chemicals. You could put them to use for example by adding them to high-strength industrial wastewater before it gets combined with the domestic sewage.”

In the group’s recent studies, appearing in Water Research and The Journal of Hazardous Materials, levels of triclosan and triclocarban were measured, to determine the degree to which these chemicals, along with other antimicrobials, become concentrated in sludge, and what happens to them thereafter. Triclosan and triclocarban account for two-thirds of the mass of all the antimicrobials in sludge, Halden found, based on a survey of 72 chemicals entering the wastewater treatment stream. Further, massive bioaccumulation of antimicrobial chemicals has been observed in various species. Earthworms exposed to triclosan, for example, showed accumulation of the chemical by a factor of 2700 percent.

Halden notes the impact these persistent chemicals can have on other life forms in the environment that are not their intended target. The thresholds for killing microbes are much higher than those for other, more fragile life forms, like algae, crustaceans and fish. “This explains why residual concentrations of antimicrobials found in aquatic environments are still sufficiently harmful to wipe out the small and sensitive crustaceans, which are critical to the aquatic life cycle and food web,” Halden says.

For certain, chemicals like triclosan and triclocarban have their place in public health, particularly in clinical settings, among people who are trained in their proper use. However, in 2005, the FDA put together an expert panel to review all the available information on these chemicals. Halden was among the voting members of this committee, which concluded that regular use of antimicrobial products by the general public was no more effective than traditional methods of proper hygiene—simply washing thoroughly with regular soap and water.

Society, Halden insists, is participating in a grand experiment in which we are all guinea pigs. While effective regulation of these chemicals is badly needed, Halden says that the inertia of regulatory agencies is a formidable obstacle. In the meantime, the best hope is for consumers to avoid triclosan and triclocarban containing products.

“The culture of fear leads people to make impulsive decisions and buy a lot of antimicrobial products that are not really needed,” Halden says. “It’s a profitable market to be in, but not one that is ultimately sustainable or a good idea.”

In addition to Halden’s appointment at the Biodesign Institute, at Arizona State University, he holds the title of associate professor in the School of Sustainable Engineering and the Built Environment, at the Ira. A. Fulton School of Engineering, ASU.

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Written by Richard Harth
Biodesign Institute at ASU
Science Writer
richard.harth@asu.edu

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Off-label meds linked to new risk

November 11, 2010 Leave a comment

Blood clot diagram (Thrombus)

Blood clot diagram (Thrombus)

If you think meds are bad when used the “right” way… you should see what happens when they’re used off-label.

Patients get all the risks–and none of the rewards.

Just look at the latest research out of Britain, which links atypical antipsychotic drugs to a dramatic rise in potentially deadly blood clots.

These are powerful brain-bending drugs approved for high- risk mental disorders such as schizophrenia… but they’re given so commonly, casually and frequently that many patients may not even be aware of the drug’s real use.

And along with a med that may not even work, these patients could be getting up to triple the risk of a blood clot.

British researchers compared data on 25,500 patients who were treated for a deep vein blood clot or pulmonary embolism between 1996 and 2007 to the records of 90,000 people who did not suffer from the clots during those years.

Overall, they found that antipsychotic meds increased the risk of a blood clot by 32 percent, and that risk doubled in the first three months.

But the highest risk of all came from the newer atypical antipsychotics. Overall, patients on these drugs had a 73 percent boost in the blood clot risk–but one drug in particular stood out.

And it’s the granddaddy of all off-label meds.

Seroquel, a drug given off-label up to three-quarters of the time, tripled the risk of a blood clot, according to the study in BMJ Online First.

Approved for schizophrenia and bipolar disorder in adults, Seroquel is frequently prescribed for insomnia, obsessive/compulsive disorder, anxiety and even dementia– despite no solid evidence it can do anything for any of those conditions.

U.S. soldiers have even been given this med off-label for post-traumatic stress… and, tragically, some have died shortly after taking it.

Earlier this year, AstraZeneca paid more than half a billion dollars to settle charges that it illegally marketed the med for off-label uses–but that’s not a deterrent.

In fact, it’s chump change next to the $1.3 billion in sales Seroquel did in the first three months of this year alone.

Meanwhile, other atypical antipsychotics are prescribed for everything from nausea to vertigo–putting people with even minor complaints at risk for a deadly blood clot.

Call that one more reason to ask questions before you take any pill–and you can start with the basics: “Is this drug approved for my condition?”

On a mission for your health,

Ed Martin
Editor, House Calls

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