Arsenic in Your Apple Juice is Safer than Dr. Oz in Your Education

There’s arsenic in apple juice, and I just poured my daughter a big glass. Go ahead, call Child Protective Services.

On his show last week Dr. Oz tried to scare us about arsenic in apple juice. It was a feat of ratings-driven fear-mongering that was shameful even by daytime TV standards. His show tested various brands of apple juice for arsenic, announced that the levels were too high, and concluded that we should all be worried.

Actually, he conducted the wrong kind of test and misinterpreted the results. (If you’re interested in the scientific details this scathing article in Forbes has a great review.) Oz was widely criticized, including by other physicians. The FDA released a very reasoned update reminding us that apple juice is safe. The FDA regularly tests apple juice for arsenic and has been doing so for years. So Dr. Oz was forced to back-pedal and reassure us that he’s not worried about drinking apple juice. Phewf! That’s a relief.

This week Oz published an op-ed in the Chicago Tribune explaining that he was simply trying to “raise an alarm” about food safety and that “we need more stringent restrictions on arsenic in fruit juice”. Huh? He said he has no concerns about the safety of juice. There’s no evidence that arsenic levels in juices (or in any other food or beverage) are dangerous and no evidence that anyone is getting arsenic toxicity from their diet. Other than that, he has a good point, or at least a very popular show.

But why did his ploy work? Why did he get so much attention? Why didn’t the couple of million people (!) who watch his show search the CDC or FDA websites about arsenic, yawn slowly, and move on to a different subject? Why didn’t they discover on their own that the scariest thing about apple juice is the calories? Overweight people shouldn’t touch the stuff. After decades of drinking fruit juices daily they might suffer the complications of diabetes, but they would still have no effects from the arsenic. Why would we take the word of a TV entertainer and thoracic surgeon about food safety instead of the opinion of people with PhDs in biochemistry who spend their careers keeping food safe? Like me, Dr. Oz last studied biochemistry as an undergraduate. The only thing his training prepares him to answer about apple juice is “How long before my heart surgery can I have anything to drink?”

For better or for worse, we’re hard-wired to pay attention to scary stuff. So a reasoned explanation that everything is OK will never get as much attention as a bogus warning that you’re poisoning your children. As an open society we are being challenged to learn to give credibility to those who have earned it and ignore those who have abused our trust. Can we do it?

To all of us celebrating Rosh Hashanah next week I wish a year of good health in which all bad things arrive only in safe doses. Posting will resume in two weeks.

Learn more:

Why You Should Trust the FDA (And not Dr. Oz) (Forbes) If you read only one article about the arsenic in apple juice story, read this one.

Apple Juice Is Safe to Drink (FDA Consumer Update)

Oz Gets Taken to Task Over Apple Juice (Neurologica Blog)

Why we raised an alarm on apple juice (Dr. Oz’s op-ed in The Chicago Tribune)

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Contaminated Cantaloupes Responsible for Listeria Outbreak

My regular readers know I have a bit of an obsession with food-borne illness. Why? Because it’s such a difficult and old problem. (Obviously germs have been contaminating food and sickening animals long before people were around.) Modern sanitation and farming have made our food much safer, but occasional outbreaks remind us that our current methods are still imperfect.

This week an outbreak of the bacterium Listeria has sickened over 20 people in seven states. (California has not been affected.) Two people have died.

The outbreak has been traced to cantaloupes grown in Jensen Farms, in Colorado. The FDA has announced a recall on cantaloupes from that farm. (California is not one of the states to which the cantaloupes from Jensen Farms were distributed.)

The Centers for Disease Control (CDC) has an information page on Listeria infection with some handy common-sense tips for preventing illness, including:

  • Thoroughly cook raw beef, pork, or poultry to a safe internal temperature.
  • Rinse raw vegetables thoroughly under running tap water before eating.
  • Keep uncooked meats and poultry separate from vegetables and from cooked foods and ready-to-eat foods.
  • Do not drink raw (unpasteurized) milk, and do not eat foods that have unpasteurized milk in them.
  • Wash hands, knives, countertops, and cutting boards after handling and preparing uncooked foods.
  • Consume perishable and ready-to-eat foods as soon as possible.

Follow the link for more suggestions.

Technology has made our food supply much safer, but we still have room for improvement.

Learn more:

FDA warns about cantaloupe linked to illness, deaths (LA Times)

FDA Ties Listeria to Cantaloupes (Wall Street Journal)

Multistate Outbreak of Listeriosis Linked to Rocky Ford Cantaloupes from Jensen Farms (CDC update)

Listeriosis (CDC information page)

Jensen Farms Recalls Cantaloupe Due to Possible Health Risk (FDA recall notice)

My previous posts about food-borne illness:

When the Stool Hits the Sprouts

Germany Struck by Major Food Poisoning Outbreak

Your Food Is Pretty Safe, But it’s Not Getting Safer

Would You Like Some Salmonella With That?

Gamma Rays are Good for Your Veggies

 

Your Food Is Pretty Safe, But it’s Not Getting Safer

 

Would You Like Some Salmonella With That?

 

Gamma Rays are Good for Your Veggies

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Primary Care Doctors Want a Raise from Medicare

Imagine that you manufacture and sell ottomans. You are very proud of the excellent ottomans that you make. You trained for many years at great expense to become an expert ottoman maker. But as your career progresses, you find yourself generally dissatisfied with how many ottomans you have to make every day to make a living, and you think that your ottomans are worth more than you’re getting paid for them.

But what really annoys you are coffee table makers. They get a lot higher prices for coffee tables than you get for ottomans even though you work every bit as hard as they do. And you’re pretty sure that ottomans are much more important to most living rooms than coffee tables. The more you think about it, the more you’re convinced that coffee table makers shouldn’t make as much, and ottoman makers should make more.

So you do the reasonable thing. You fire off a letter to the Central Committee for Living Room Furniture Allocation (CCLRFA) and demand that ottoman prices be raised and coffee table prices lowered.

It sounds like an Orwellian dystopia, but that’s exactly what’s happening in healthcare.

The American Academy of Family Physicians (AAFP) believes that primary care doctors are not being paid enough by Medicare, and that Medicare overvalues services provided by specialists. In any rational marketplace, primary care doctors (or at least some of them) would simply raise their prices. But in the price-fixed world of Medicare, the prices aren’t set by patients or doctors, so the AAFP is left arguing with the CMS (Centers for Medicare & Medicaid Services) about the RUC (Relative Value Scale Update Committee).

Feel free to follow the links below for a mind-numbing look at the arcane world of healthcare reimbursement.

Though I am obviously a primary-care doctor, it’s hard for me to have much sympathy for the AAFP. Forget the fact that the central control of prices has been disastrous everywhere it has been tried, and that Medicare’s task of setting the prices that thousands of doctors receive for hundreds of services is absolutely impossible. With healthcare costs exploding, and with healthcare being one of the few sectors that (because it is heavily subsidized) continues to grow during the economic slump, it seems outlandish that doctors would ask current taxpayers for a raise. It’s actually worse than that. Because of our debt, current expenditures aren’t even paid by current taxpayers but rather by future generations. So the AAFP would like your grandkids to pay your doctor more for your care.

Do I think most primary-care doctors work hard and try to do a good job? Absolutely. Do I think they’re under paid? I have no idea. The only way to accurately value something is in a free marketplace.

If family doctors want to earn what they’re worth, they should work for their patients and find out how much their patients are willing to pay. If they want to start internecine bickering with specialists over who gets to bankrupt the country first, they should renew their membership in AAFP.

Learn more:

Differences in Doctors’ Compensation in the Spotlight (Wall Street Journal Health Blog)

Primary-Care Doctors Push for Raise (Wall Street Journal article)

Higher Fees Paid To US Physicians Drive Higher Spending For Physician Services Compared To Other Countries (Health Affairs, abstract available without subscription)

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A Revolution in Atrial Fibrillation Treatment

Atrial fibrillation is an irregular heart rhythm affecting about 3 million Americans. The most serious risk of atrial fibrillation is stroke, caused by a blood clot forming in the abnormally beating heart chambers and traveling to a blood vessel in the brain. For over 50 years the mainstay of atrial fibrillation treatment has been the anticoagulant warfarin (better known by the brand name Coumadin) which effectively decreases the risk of stroke by preventing blood clots.

By the way, medicines that prevent blood clots are frequently called “blood thinners”, but they don’t thin the blood or affect blood viscosity. They prevent clotting. “Anticoagulant” is a more accurate term. Use the word at your next party (ideally while holding a bloody Mary) and your friends will marvel at your verbal precision.

Where was I? Oh, yeah.

Warfarin is probably the least convenient and most dangerous medication in common use. The reason is that the amount of anticoagulation caused by a given dose of warfarin varies wildly from one patient to the next and also varies in the same patient over time. Other medicines and certain foods can increase or decrease the anticoagulation caused by warfarin. Frequent blood tests are therefore required to adjust the dose. Too much warfarin increases the risk of life-threatening bleeding. Too little warfarin raises the risk of stroke from atrial fibrillation.

A group of new medications are now promising to eliminate the dangers and hassles of warfarin. I wrote two years ago about dabigatran (Pradaxa), an anticoagulant which is now on the market and is at least as safe and as effective as warfarin. Since then, another anticoagulant, rivaroxaban, has also been shown in a large trial to be superior to warfarin in safety and efficacy.

This week a third anticoagulant, apixaban, joins the group proven to be superior to warfarin. A study published in the New England Journal of Medicine (NEJM) randomized over 18,000 patients with atrial fibrillation to warfarin or apixaban. The patients were followed for almost two years. The patients on apixaban had fewer strokes, fewer episodes of major bleeding, and less mortality. An accompanying editorial in NEJM proclaims “a new era for anticoagulation in atrial fibrillation”.

Besides the fewer episodes of bleeding and stroke, a major advantage of these new medications is that they are prescribed at a fixed dose and do not require blood test monitoring.

Like many new medications, these new anticoagulants are relatively expensive (though less expensive than having a stroke or a life-threatening bleed). And like many old medications, warfarin is dirt cheap. So the transition away from warfarin may take some time. Nevertheless, its days in use for atrial fibrillation are numbered. Afterwards, it will likely still be useful in another role it has played for many years – as rat poison.

Learn more:

Study Gives Lift to Drug That Cuts Stroke Risk (Wall Street Journal article, see especially the handy chart summarizing the new anticoagulants)

A New Blood Thinner May Outperform Coumadin (My post two years ago about Pradaxa, dabigatran, the first oral alternative to warfarin.)

A New Era for Anticoagulation in Atrial Fibrillation (New England Journal of Medicine editorial, free without subscription)

Apixaban versus Warfarin in Patients with Atrial Fibrillation (New England Journal of Medicine article, free without subscription)

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Vaccines Are Much Safer than the Diseases They Prevent

red bumpy rash

A child develops a fever of 104 ⁰F, cough, runny nose and red eyes. A few days later she develops a red bumpy itchy rash as in this photo. Any guesses as to the diagnosis? Many of us would be stumped, having never seen this disease. This is the classic presentation of measles, which prior to the development of the measles vaccine in the 1960s affected hundreds of thousands of U.S. children annually. There is no treatment. Complications from measles caused 3 fatalities for every one thousand cases.

With the near disappearance of vaccine-preventable illnesses a full generation ago, today’s parents don’t have personal memory of the misery and fear that illnesses such as mumps, polio and rubella caused. Instead, fueled by a simmering mistrust of modern medicine and of science generally, some anti-vaccine groups have raised concerns about possible side effects of vaccines. The best known such concern was fueled by the fraudulent scientific study linking the MMR vaccine with autism. (I posted about this paper, its retraction, and the damage it did in January.)

A report released by the Institute of Medicine this week analyzed over 1,000 studies and detailed what is currently known about vaccine side effects. The report is over 600 pages long, and I promise you that I’m not going read it all. The report concludes that “while no vaccine is 100% safe, very few adverse events are shown to be caused by vaccines.” The report also highlighted that vaccines do not cause some of the side effects that have been receiving much attention. The MMR vaccine was again found not to cause autism or childhood diabetes. Flu shots also do not cause asthma exacerbations or Bell’s palsy.

Vaccines do sometimes cause adverse events, and the report identifies 14 such adverse events that are known to be vaccine related. Febrile seizures in children, severe allergic reactions and fainting are some of them.

But none of them are as dangerous as polio, or measles, or tetanus or a handful of other diseases I hope to never see.

Learn more:

Vaccine Cleared Again as Autism Culprit (NY Times)

Report Finds Few Health Problems Tied to Vaccines (Wall Street Journal Health Blog)

Study Linking Vaccines to Autism not Just Wrong, Intentionally Fraudulent (My last post about vaccine safety, which at the bottom has more links to my previous posts on the anti-vaccine movement and vaccine refusal)

Measles (Wikipedia article)

Adverse Effects of Vaccines: Evidence and Causality (Institute of Medicine publication)

Photo credit: Centers for Disease Control Public Health Image Library, CDC/Dr. Heinz Eichenwald (ID 3168)

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Keep Calm, Carry On, and Get Your Flu Shot

Ah, the magical serenity of mid-August! Students face the new school year with dread, parents face the new school year with joy, London is set ablaze, Syria shells its own civilians, and the stock market behaves like a brick thrown out of an airplane window.

But for primary care doctors, mid-August is the time when the new flu shots arrive. Our office received a batch this week. The flu season is not yet upon us, but it’s not too early to get your flu shot.

Who should get the flu shot? Since last year, the CDC has been recommending the flu shot for everyone over 6 months, but the people for whom the flu shot is particularly important are:

  • Children younger than 5
  • Adults 65 or older
  • Pregnant women
  • People with chronic illnesses that would make flu more dangerous
  • Health care workers
  • Household contacts of people at high risk for complications from flu
  • Household contacts and caregivers of children younger than 6 months

Take a look at the CDC Seasonal Flu Shot page for details.

Who should not get a flu shot?

  • People who have ever had a severe allergic reaction to eggs
  • People who have ever had a serious reaction to a previous flu shot
  • People with a history of Guillain–Barré Syndrome that occurred after receiving influenza vaccine

So make an appointment to get your flu shot. Because the only thing I can think of worse than a double-dip recession would be a double-dip recession with the flu.

Learn more:

CDC Questions and Answers: Seasonal Flu Shot

Keep Calm and Carry On

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Linaclotide is Safe and Effective for Chronic Constipation

Chronic constipation affects about one in six people in the U.S. and is a problem that primary care doctors hear about very frequently. Symptoms include infrequent bowel movements, hard stools, straining, abdominal bloating and discomfort, and a sense of incomplete evacuation. It’s not a dangerous problem, but it causes plenty of misery for lots of people. Though doctors have a few remedies for chronic constipation (which I’ll list at the end of this post) they are only temporarily and modestly effective.

This week’s New England Journal of Medicine publishes the results of two trials testing a new medication, linaclotide, for chronic constipation. Linaclotide is taken orally as a capsule once a day. The two studies together randomized over two thousand patients with chronic constipation to linaclotide or placebo. The patients were followed for 12 weeks to assess improvement in their symptoms.

The patients taking linaclotide had significant relief of their symptoms. (The specifics are detailed in horrifying clarity in the article.) Unlike laxatives which lose effectiveness with repeated use, linaclotide continued to be as effective at the end of the trial as at the beginning. There is also a rebound effect with the chronic use of laxatives in which after stopping the medication patients are more constipated than before they started. This rebound effect was not observed with linaclotide.

Linaclotide also appears to be safe. The most common side-effect, as you would expect, was diarrhea.

Linaclotide is not yet available to patients. It has yet to go through the FDA approval process. I suspect a few patients will be emailing me daily to check if it’s on the market yet. In the meantime, our advice to patients with chronic constipation remains the following.

  • Drink lots of fluids (not counting alcohol or caffeine)
  • Increase your physical activity
  • Eat more fiber, perhaps in a fiber supplement
  • Use laxatives only intermittently

WebMD also has a very informative slideshow about constipation.

Learn more:

No more laxative? The drug linaclotide helps relieve constipation (LA Times Booster Shots)

Experimental Drug May Treat Chronic Constipation (WebMD article)

Myths and Facts About Constipation (WebMD slideshow)

Two Randomized Trials of Linaclotide for Chronic Constipation (New England Journal of Medicine article. Summary available without subscription.)

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A New Species of Tick-Borne Bacteria Identified in Minnesota and Wisconsin

[Lunch warning: Parts of this post are kind of gross. If you’re reading this over a meal, you have been warned.]

What a depressing week. The debt ceiling debate postponed all difficult decisions, second quarter economic growth was revised so low that you need to squint to see it, and yesterday the stock market jumped off the balcony, losing all the gains it’s made over the year.

We need some happy news to distract us from what we used to call our portfolios. How about a new disease spread by tick bites?!!

Ehrlichiosis (er-lick-ee-OH-sis) is a disease characterized by fever, muscle aches and headaches. A third of the cases also have a rash. Severe cases can be fatal, but that amounts to fewer than five deaths per year.  It’s treatable with antibiotics. Ehrlichiosis is caused by two species of bacteria, Ehrlichia chaffeensis and E. ewingii which are spread by the bite of the lone star tick. The lone star tick is really ugly, so here’s a picture of it.

The lone star tick is really ugly.
lone star tick

As you would guess from its name, the lone star tick is found largely in the South, and that’s where cases of ehrlichiosis have usually occurred.

This week’s New England Journal of Medicine published a study which describes a new geography, a new bacterial species, and a new transmitting tick for ehrlichiosis. It describes patients with the typical symptoms of ehrlichiosis in Minnesota and Wisconsin. The bacteria isolated from these patients belongs to the genus Ehrlichia but is a newly discovered species. It is spread by the deer tick, which like the lone star tick is also not a contender for the most beautiful organism.

The deer tick is visually unappealing.
deer tick

The deer tick also has the distinction of spreading the bacterium that causes Lyme disease as well as other infectious diseases. Since 2009 there have been 29 identified cases of infection with this new species of Ehrlichia in Minnesota and Wisconsin.

Will this new species spread across the US, giving the deer tick super powers and triggering the inevitable zombie apocalypse? Probably not, but it is likely to spread from its current geography.

The simplest way to manage ehrlichiosis is prevention. Preventing tick bites prevents ehrlichiosis and lots of other tick-borne illnesses. The CDC website has a very handy page about ehrlichiosis with tips for preventing bites and removing attached ticks. When going on hikes remember to wear long pants and to use insect repellant.

So there you go – a pleasant story to distract us from our creeping, blood-sapping, infectious economic woes.

Learn more:

Centers for Disease Control and Prevention Ehrilchiosis page

There’s a New Bacterial Species Causing Tick-Borne Illness in Two States (Wall Street Journal health Blog)

Yet Another Reason To Say Ick to Ticks (NPR health blog)

Emergence of a New Pathogenic Ehrlichia Species, Wisconsin and Minnesota, 2009 (New England Journal of Medicine, abstract available without subscription)

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Mammogram Reading Not Better With Computer Assistance

… or “Read this mammogram, HAL.” “I’m sorry, Dave. I’m afraid I can’t do that.”

I went to college in the late 1980s, at perhaps the peak of optimism about computer intelligence. Personal computers had just become available and there was a general expectation that computers would soon be driving our cars, accepting our commands in spoken English, and generally doing everything better than humans could.

The reality has been much less consistent. There have been impressive gains in computer intelligence applied to some specific tasks, like chess. But there has been remarkably little progress in others fields, like transcribing spoken language. Transcription software is still notoriously error-prone, and transcription by humans remains much in use.

At first glance, reading a mammogram seems like the perfect task for a computer program. The software would just need to recognize the characteristic appearance of breast cancer and the appearance of normal breast tissue. It would not be biased by factors that can affect radiologists, like fatigue or anxieties about making an error.

Indeed, such software exists. Computer-aided detection (CAD) technology is computer software that performs a second reading of a mammogram which is supposed to point out abnormalities on the mammogram the radiologist may have missed. It does not replace a radiologist’s reading, but was intended to help the radiologist detect more cancers and perhaps detect cancers earlier. It was FDA approved and is currently used in the reading of about three quarters of mammograms in the US.

Except it might not help.

A study published this week in the Journal of the National Cancer Institute looked at 1.6 million mammograms done at 90 facilities over 8 years. Some facilities used CAD, and some did not. The study found that CAD did not lead to increased detection of cancers or to detection of cancers at earlier stages. Worse, CAD led to an increase in false positives – mammograms read as abnormal that led to normal biopsies. That means that CAD led to an increase in biopsies without actually helping patients.

That’s not exactly what we hoped for from intelligent machines. That’s much less like Rosie, the Jetsons’ unflappable household robot, and more like HAL, the computer in 2001: A Space Odyssey.

Of course this study shouldn’t be the last word on CAD. Technologies improve all the time, and the fact that it’s not helpful now doesn’t mean it won’t be in a few years. But until some improvements are made, the best software for reading mammograms is still behind the eyes of a radiologist.

Learn more:

Computers Still Not a Big Help With Reading Mammograms (Wall Street Journal Health Blog)

Mammograms: Computer-aided detection doesn’t help (LA Times Booster Shots)

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The Power of Placebo

We’ve all heard of the power of the placebo effect – the benefit from receiving an inactive medication or a phony simulated treatment. But how do placebos work? Do they improve objective measures of disease? Do they improve the patient’s subjective symptoms? Do they do both? A cleverly designed study in last week’s New England Journal of Medicine (link 1 below) answers that question.

The investigators chose asthma as the disease in which to study the effect of placebo because asthma can cause uncomfortable symptoms – wheezing, breathlessness – but can also be assessed objectively through lung function tests. The study enrolled patients with stable mild or moderate asthma. Each patient attended treatment sessions on 12 different days in which they received one of four treatments, so they received each treatment three different times.

One treatment was an albuterol inhaler. Albuterol is the standard medication for rapid airway dilation and is very commonly used by asthma patients. The second treatment was an inhaler with no active medication. Patients taking either the albuterol or placebo inhalers were not informed about the contents of the inhaler, and neither were the investigators monitoring them.

The third treatment was sham acupuncture. Sham acupuncture looks to the patient as if needles are being inserted in his skin, just as in traditional acupuncture. The patient also feels the needle poke. But the needle actually retracts into a sleeve (like prop theater swords) and never penetrates the skin.

The fourth treatment was no intervention. The patient was simply asked to wait a few hours before leaving.

Before and after each of the treatments the patients’ lung function was measured. After each of the treatments the patients were also asked to rate the improvement of their asthma symptoms.

The results were fairly dramatic.

The lung function tests improved substantially after albuterol, as expected, and didn’t improve significantly with the placebo inhaler, sham acupuncture or no intervention. But the patients’ perceived improvement did not match their lung function improvement. Patients reported no symptom improvement after a session of no intervention. They perceived significant symptom relief after albuterol, and they perceived equal symptom relief after the placebo inhaler and after sham acupuncture even though their lung functions did not improve with these interventions.

So the patients’ symptoms were relieved equally by any kind of perceived treatment, by what the authors of the study call “the ritual of treatment”. But lung function improved only with active medication.

What are we to learn from this? The authors of the study assert that this means that in diseases such as asthma we should be sure to follow objective disease measures, since the patients’ reports may lead us astray. An editorial in the same issue (2) disagrees and asserts that symptom relief is point of asthma treatment, not necessarily normalization of objective tests.

The right balance likely depends on the disease. Some diseases, like high blood pressure, have no symptoms. Objective tests have to be the benchmark of treatment. Other diseases, like migraines and fibromyalgia, have no objective findings. Clearly these must be treated with subjective symptom relief as the goal. Most illnesses are somewhere in between, and both active medication and the “ritual of treatment” have a valuable role.

Learn more:

(1) New England Journal of Medicine article: Active Albuterol or Placebo, Sham Acupuncture, or No Intervention in Asthma (full text by subscription only)

(2) New England Journal of Medicine editorial: Meaningful Placebos — Controlling the Uncontrollable (full text by subscription only)

Wall Street Journal Health Blog: The Placebo Effect, This Time in Asthma

Los Angeles Times Booster Shots: Asthma study reveals the power of the placebo effect

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