Archive for March, 2012

Chocolate: a new medicine? Part One

Tuesday, March 27th, 2012

Dark chocolate, in small amounts, is good for youI was reading The Wall Street Journal this morning and came across an article titled "A Chocolate a Day to Get Slimmer?" I'm not a major chocolate eater, but had heard something on NPR about this study yesterday, so ate eight small pieces of dark chocolate at a board meeting last evening. Then, when I weighed myself before breakfast today, I realized I was down 2.8 pounds.

Should I continue this increased chocolate consumption or was that, as I of course knew, just "water weight" I'd lost? The previous night I'd eaten a prolonged meal with friends at our favorite Thai restaurant and the next morning had gained over three pounds.

Let me digress a bit. Whenever I mention water weight I'm really referring to fluid that the body keeps because of dietary salt excess. I normally don't use table salt, as I have a family history of high blood pressure and was aware that most of us, eating a typical American diet, were ingesting far too much sodium, the crucial element in table salt. When I eat out I expect my weight to bounce up a few pounds and don't worry about that short-term increase. The salt in the food causes me to retain fluid and therefore to gain weight temporarily. Many diet plans that advertise losing five or more pounds in the first week are really helping people get rid of water weight.

Okay, back to chocolate. The article I mentioned is important, but the message it's carrying is nothing new. In 1973 I saw Woody Allen's movie, "Sleeper" in which he plays a nerdish store owner who is revived out of cryostasis (a form of preservation using ultra-cold temperatures) after 200 years. In that future world science has shown chocolate to be good for you.

Two prominent food gurus, Andrew Weil and Den Ornish, mention health benefits of chocolate. I found Dr. Ornish's 2007 Newsweek article,"Chocolate to Live For," in which he mentions a host of medical studies showing dark chocolate, which has higher amounts of beneficial chemicals called flavinoids, may lower blood pressure and and improve blood flow to your brain and heart. White chocolate and milk chocolate have very small amounts of flavinoids and bitter dark chocolate has the most.

Eat a small bite of dark chocolate and meditate

The phrase "moderation in all things" dates back more than two thousand years to a Roman "comic dramatist." It certainly applies here. None of the articles I read were about eating a lot of extra calories in the form of chocolate. Dr. Ornish's approach made sense to me; he very slowly eats a bite of dark chocolate, meditates while doing so by focusing on the experience with all of his senses, and regards the very first bite as being the most pleasurable.

What a great way to eat something he regards as a special treat as well as a health food.

I've never tried that with chocolate, but having read his magazine piece, I'll try that approach.

I'll continue with more medical background on chocolate in my next post, but to whet your appetite will give you a link to today's article in WSJ.

Happy chocolating.




Toxins for tots and the rest of us too: part one

Saturday, March 24th, 2012

This speaks for itself

All of us are exposed to potentially dangerous substances in many of our household products, but there's been increasing concern that pregnant women need to pay special attention to  the ever-growing list of chemicals around the home. I just read an article published in The New York Times nine days ago with the gripping title "Is It Safe to Play Yet?" The subtitle described what's going on in many families: "Going to Extreme Lengths to Purge Household Toxins."

I found a reference to an extraordinary study which examined umbilical cord blood samples drawn from ten infants of minority heritage: African-American, Asian or Hispanic. Five independent laboratories were involved and up to 232 toxic chemicals were found. I was familiar with the Environmental Working Group, one of the two non-profits who commissioned the research, but not with Rachel's Network which I found online. It's a women's organization named in honor of Rachel Carson whose book, Silent Spring, in many aspects launched the modern environmental movement.

EWG had been unable to find any published studies focused on minority group infants, yet some of their homes are more likely to be situated near busy highways and roads, to be closer to industrial shops and factories and to have been built before current safety standards were established.

Other studies have found up to 358 chemicals in cord blood of US infants; some are acknowledged as possible cancer-causing agents, nervous-system toxins or endocrine hormone disrupters. The National Institute of Environmental Health Sciences (NIEHS), part of NIH, says those latter toxins can be found in metal food cans, plastic bottles, food, toys, cosmetics, detergents, pesticides and flame retardants. Their adverse effects have increased potential to harm fetuses and young babies as their bodies develop.

asbestos can cause mesothelioma, a rare cancer usually of the lining of the lungs and chest cavity

Our Toxic Substances Control Act, is a 1976 law that, unfortunately, grandfathered most existing chemicals. The Environmental Protection Agency (EPA) was mandated to protect the public by regulating the manufacture and sale of chemicals But 60,000 chemicals were excluded because they were already in use and over the following years the EPA succeeded in restricting only five of those: one was asbestos, but two years after the chemical was banned the rule was overturned by the Fifth Circuit Court as being too broad.

In contrast, the European Union, in 2007, passed REACH, the Registration, Evaluation, Authorisation and Restriction of Chemicals act that applies to all chemical substances; not only those used in industrial processes but also in day-to-day lives, for example in cleaning products, paints as well as in articles such as clothes, furniture and electrical appliances.

REACH places the burden of proof on companies. To comply with the regulation, companies must identify and manage the risks linked to the substances they manufacture and market in the EU. They have to demonstrate to a governmental agency how the substance can be safely used, and they must communicate those risk management measures to the users.

One estimate, published in Health Affairs in 2011, estimated the US spends $76.6 billion a year on kids' medical issues that may be related to their environment.

We have a long ways to go, both in determining which chemicals are actually risky and banning or controlling their use.

And, on the other hand, knowing which chemicals, old and new, are safe for us and our offspring.

Don't vacillate, vaccinate instead!

Wednesday, March 21st, 2012

Could she have measles?

The Wall Street Journal this morning had an article titled, "Where Could The Next Outbreak Of Measles Be?" A secondary heading on a later page said, "Low Vaccination Rates Trigger Fears," and there was a US map showing problem areas. Boulder, Colorado was one of those hot spots.

The article led me back to the concept of "herd immunity," very well illustrated on a webpage from the National Institute of Allergy and Infectious Diseases. Basically it says we need a relatively high percentage of a given population to be vaccinated (AKA immunized) against a given disease in order to prevent epidemics.

The particular viral disease I'm writing about is measles, sometimes called "red measles" or, technically, rubeola. The National Library of Medicine has an excellent, brief description of this ailment and notes that before widespread vaccination became common, most people had a case of measles before age 20.

Then the MMR vaccine was developed by a Merck scientist in the 1960s. Measles incidence went from being, as a 1954 quote termed it, "as inevitable as death and taxes," to an uncommon to rare disease in developed countries. In the US for the twenty years after the vaccine was licensed, an estimated 52 million overall cases, 17,400 leading to mental retardation and 5,200 deaths were prevented.

In 2000 the WHO estimated that there were still ~45 million cases of measles worldwide yearly causing 800,000 deaths. While mortality in developed countries was ~1/1000, in sub-Saharan Africa, mortality was 10%. In cases with complications, the rate could rise to 20–30%. On average, ~450 children died every day from measles. By 2007 immunizations had cut the yearly global death rate by 75%.

But in 1998 an article in The Lancet had caused a stir that has continued to this day. A British gastroenterologist reported a series of 12 young patients who were referred to his practice with bowel complaints. Their average age was six and 8 of them developed symptoms of autism within a month after they got their MMR injection.

Should I believe what I just read?

Many parents hearing about this report stopped their children's immunizations. This was in spite of numerous much larger studies showing no connection between MMR and autism. In 2005 a Japanese group showed an increase in autism diagnoses in children who got their childhood immunizations after the country's particular MMR vaccine was withdrawn from use because of a suspected side effect of the mumps component. In 2009 a review of multiple large studies was published examining three linkages that had been proposed: MMR and autism, thiomerosal (a mercury-based preservative chemical used in some vaccines, but not in MMR) and autism, multiple vaccinations and autism.

The accumulated data from these large groups in a number of countries showed no association between any of these factors and autism. Finally in 2010 The Lancet published a rather wishy-washy retraction of the Wakefield article.  His license had been revoked by the UK General Medical Council and the British Medical Journal's editorial staff published a much stronger condemnation of Wakefield's work in 2011, calling it fraudulent.

And yet today's WSJ article note parts of the US, especially in the northwest, have relatively poor compliance rates with vaccination guidelines. Parents can opt out because of medical, religious or even philosophical concerns. Low-income kids can receive free immunizations under a federally-funded programs, but one physician interviewed said the parents in his practice who don't want their kids vaccinated are wealthy and well-educated.

We've seen some minor outbreaks in the past few years. If we don't overcome parental misinformation and fears, we may have a major epidemic.


Influenza H5N1 HPAI research: lots of viewpoints

Friday, March 16th, 2012

When experts disagree, who should we believe?

Shortly after I wrote my post on the dangers of H5N1 HPAI, my weekly copy of JAMA, AKA the Journal of the American Medical Association, arrived containing a commentary titled "International Debate Erupts over Research on Potentially Dangerous Flu Strains." The pros and cons of release of the two groups' research were discussed and the rationale for publishing the methods and details was explained.

One expert in the field had a balanced view. He felt release of the details of the recent research on H5N1 HPAI might be extremely useful to  those who evaluate which strains of influenza are about to pose a real threat to humans and could potentially cause epidemics. Doing so might provide lead time for other scientists who work on vaccines to prevent wider spread of the particular strain of flu.

But in a January, 2012 online discussion of the controversy the head of a university Center for Biosecurity felt the lives of hundreds of millions of people could be at risk if such an engineered virus strain were to be released, even accidentally. He feels that continued research would require the level of biosecurity utilized with other dire agents such as smallpox.

The first infectious disease specialist countered with the concept that H5N1 HPAI wasn't an especially likely pick for those interested in bioterroism. It's certainly not a selective weapon and its use would require considerable expertise.

The second expert noted there had been no data that such a strain of flu would ever develop naturally, outside the lab, and we had to return to the concept of weighing potential harm versus good.

Now the original researchers have stated that the new viral subtype isn't as deadly as feared; it hasn't killed the ferrets being used as laboratory substitutes for humans and has proven to be controllable with vaccines and antiviral medications. Because of ethical limitations it hasn't been tried on human subjects and they don't know whether it even could be spread among humans.

And which of these is the worst?

I think we're treading very close to the edge here. I don't look forward to widespread beneficial effects of complete publication of the ongoing lab research results. And I do fear the possibility of groups who don't care if they kill off a third of everyone, including their own followers. Accidental release of a lab-engineered organism into the human population could also happen, even if unlikely.

Another online article said the work on the mutant form of H5N1 had been performed in BS-3 labs, used for studying agents that can cause serious or lethal disease, but do not ordinarily spread among humans and have existing preventives or treatments.

A GAO 2009 report counted 400 accidents at BS-3 labs in the previous decade. Scientists argued that the H5N1 HPAI studies must be moved to BS-4 labs with one professor stating, "An escape would still produce the worst pandemic in history." Yet between 1978 and 1999, over 1,200 people acquired deadly microbes from BS-4 laboratories, the biosafety-4 level facilities that normally deal with infectious agents that have no known preventive measures or treatment.

Scandia National Laboratory's International Biological Threat Reduction program directed by Ren Salerno has a worldwide ongoing effort to prevent laboratory accidents, but there are varying standards for biosafety and at least 18 BS-4 labs outside of the US as of 2011.

So I'm still worried.


Dangerous research on influenza H5N1, the "bird flu"

Tuesday, March 13th, 2012

This "chicken" is safe to handle

I just looked at the World Health Organization's (WHO) most recent statistics on human cases of avian influenza H5N1, the dreaded bird flu. These cover the period from 2003 through March 10, 2012 and report 596 total cases and 350 deaths. The counties with the great numbers of cases are Indonesia, Egypt and Vietnam and I didn't see any reports of bird flu infections in the Western Hemisphere...yet.

That's a relatively tiny number of cases, but an incredibly high percentage of deaths, nearly 60% of those infected. But influenza epidemics and pandemics have been a common occurrence in the last century. So what's the difference between our seasonal flu, the pandemics and this new flu?

The Food and Agriculture Organization of WHO has published the first three chapters (of nine) of an online primer on avian influenza. It seemed a good place for me to start.

The first issue is how easily a new flu virus passes from animals  to humans (the usual hosts are birds, typically ducks and, secondarily, chickens, especially if flocks are raised in proximity to each other and the ducks are "free range") and then from one person to another. The second is how deadly the particular influenza virus is.

Up until now those infected with the relatively new H5N1 subtype, sometimes called H5N1 HPAI, have had direct or at least indirect contact with infected birds. The HPAI is the acronym for "Highly Pathogenic Avian Influenza," but in this case highly pathogenic, which translates into very likely to cause disease, mostly refers to birds. Unlike seasonal flu, there's been (thus far) absolutely no documented human-to-human spread of the virus.

The 1918 Spanish flu infected 1/3 of everyone alive and killed at least 20 million. My math says that's roughly 4%, but 3% is the usual quoted figure. Seasonal flu kills less than 0.1% of those infected. So this flu, if it does reach a human, is terrible.

These experiment may prove deadly

Recently there has been an enormous flap about the work done in two laboratories. I had heard about the issue, but hadn't read the details until my monthly copy of On Wisconsin arrived and I realized one of the labs was in Madison. CNN has an online review of the problem. The researchers wondered why this deadly flu variety hasn't spread from person to person, so they created a mutated form that could be easily transmitted from one mammal to another using ferrets as their test animal.

Then the excrement collided with the rotating blades. Detailed papers were about to be published in prominent, widely read journals, Nature and Science. The National Science Advisory Board for Biosecurity temporarily stopped the process, saying the papers should be published without methods or details to stop terrorists from making their own highly lethal and easily spread virus strains.

Think about it; if this virus subtype gets released it could potentially infect a third or perhaps all of all of us now alive and kill 60% of those whom it strikes. We have a world population of roughly 7 billion now, so that's somewhere between 1.4 and 4.2 billion deaths.

Yet many in the scientist community seems to think all the details of the research should be given to those responsible groups that need help with H5N1 HPAI.

I'm worried.

The "sex life" of a virus

Saturday, March 10th, 2012

The double helix

Most of us who are adults (and many who are not) have personal knowledge of human sexual reproduction, the process by which a man and a woman each contribute genetic material that contains DNA (deoxyribonucleic acid), the chemical basis of new life. DNA is an incredibly long twisted molecule. Its structure is a double helix with two strands composed of a sugar-phosphate backbone linked by four specific chemicals: adenine (A), thymine (T), cytosine (C) and guanine (G). These are called bases and match up in specific pairs, A always with T and G with C.

DNA has an amazing ability to replicate itself; the strands separate and each becomes the pattern for a duplicate to be constructed. Occasional mistakes are made, but we have a cleanup chemical, DNA polymerase, a kind of automatic spellchecker, that makes corrections.

Our human DNA has about 3 billion pairs of these bases; yours and mine and Cousin Flo's will be 99% identical. The remaining 1% is what makes the difference between an Einstein, a sports hero, a jazz musician and you and me. Our DNA is 98% the same as a chimpanzees and 85% the same as a mouse, but these comparisons clearly understate the importance a single base pair difference can make.

Viral "reproduction" is quite different. Influenza viruses don't have DNA; instead they contain RNA and have to replicate in living cells. Once they are inside one, the process results in many viral "offspring." These eventually leave to infect other cells in the organism and in doing so kill the one they replicated in. RNA (ribonucleic acid) is somewhat like DNA, but has one different base and a slightly different sugar in its "backbone." It's usually found as single strands shorter than those of DNA or, in the case of the flu virus, in seven or eight pieces. It lacks a proofreading enzyme so most of the new influenza virus copies are actually mutants.

Most of these changes, called antigenic drift, are minor. So the flu shot I get every year, which is an educated best guess as to what this years flu virus will be, offers considerable, but not total protection.

flu shots make sense

Sometimes the mutations are more significant; the process is called antigenic shift. That may occur when a host is infected with two different influenza viruses at the same time. The swine flu, for example, contained genes from pigs, humans and birds. When this happens, pandemics may occur.

Influenza is spread in several different ways: an infected person coughs or sneezes and you inhale the aerosolized virus; humans may come into direct contact with bird droppings or nasal secretions; various surfaces may become contaminated (viral particles in mucous may survive several weeks on banknotes).

Modern techniques for producing new flu vaccines rapidly may prevent millions of deaths and steps toward a "universal flu vaccine" are being researched. In the meantime logical precautions and yearly flu shots can save lives.



Viral Diseases: Influenza, Part 2

Thursday, March 8th, 2012

Homo Habilis, the first member of the genus Homo

I realized, as I wrote my last post, that I was using medical jargon that might make no sense to most readers. So I want to examine how the influenza virus is described by doctors, specialists in epidemics (AKA epidemiologists) and other scientifically-trained groups.

First of all let's briefly talk about how we classify everything that is alive. There's a complex system called taxonomy which is conventionally used to group separate different  groups of dissimilar and similar organisms. It has seven major layers, or taxa. Humans, for example,  belong to the kingdom Animalia, the phylum Chordata, the class Mammalia, the order Primata, the family Hominidae, the genus Homo and the species Homo sapiens. 

Flu viruses fall into three genuses, and those logically enough are called A, B and C.  The A type has only one species, lives in nature in wild aquatic birds (but can infect other animals), and causes the most severe diseases in humans. Subtypes of flu A can be identified by a variety of laboratory tests that determine which kind of two glycoproteins (complex chemicals that contain both carbohydrate and protein constituents) are found on the surface of the virus.

One of those is called hemagglutinin (H for short) and the other neauraminidase (N). There are 16 H types and 9 Ns; Hs bind the virus to a cell and help it insert its genetic information into that cell. Ns get involved later in the infection and help the virus release its "offspring" from the cells they were produced in.

Laboratory tests can show which H and N are present.  Both are antigens, substances that can cause an immune reaction if taken into your body by one route or another (e.g., breathing them in) and cause your body to produce antibodies, chemicals that are produced to combine with and counter the effects of the antigen. Some important influenza viruses are H1N1 which caused the 1918 Spanish Flu and the 2009 Swine flu, H2N2 (Asian flu of 1957), H3N2 (Hong Kong Flu 1968) and H5N1 (Bird Flu in 2004).

The CDC's short article on types of influenza viruses mentions there are seasonal epidemics nearly every winter in the United States; those are caused by type A or B, not by type C. All of the terrible flu pandemics have been caused by type A flu viruses. The B virus types are normally found only in humans (seals and ferrets are the only other animals that can be infected by flu B).

We get ours every year

Why is type A the killer? It mutates much more rapidly than B, usually by minor changes in the H and N  surface proteins, occasionally by sudden major changes. The first kind of change may alter the antigens you can be exposed to so the antibodies you've developed to fight off a flu infection don't work. That's also why the vaccine you get, which contains two A subtypes and one B strain, may not fully protect you. That's not a reason to skip your flu shot.

The other kind of mutation is more serious and I'll write about it next.


Viral diseases old and new: Let's just begin with the flu

Sunday, March 4th, 2012

A cause for alarm and action

Two days ago I began a post on zoonoses, diseases that spread from animals to humans. As usual, my interest led me from one fairly-limited topic to more-generalized subjects and I eventually decide to write a multi-post discussion of viral diseases that either have caused massive, widespread epidemics (AKA pandemics) or could potentially lead to them.

The number of deaths they have resulted in is staggering. HIV/AIDS has killed over 25 million of us in the past 30 years; the Black Plague over a 330-year period killed 75 million and smallpox is estimated to have caused over 300 million deaths over the centuries.

But let's start with influenza, the virus that we read about year after year as a worldwide threat. In the fall my wife and I get flu shots; we got used to doing so when we were both on active duty as Air Force medical staff personnel. It was routine; I didn't pay a lot of attention to what this year's shot contained and only vaguely kept up with anything written about the flu itself.

Then so-called "bird flu" came along and  the world geared up for a terrible pandemic.Usually the kind of influenza virus found in birds doesn't infect humans. But one unusual strain, called H5N1 (I'll explain what that means later) killed a six-year-old boy in Thailand in 2003. Of the people who caught this virus, 60 % died.

Most of us have heard about the Spanish flu, a major pandemic that infected a third of everyone living in 1918-1919 and caused 20 to 40 million deaths worldwide. Yet only 3% of those whom the virus infected died from it.

The so-called Asian flu pandemic in 1956-1958 causes 2 million deaths; the Hong Kong flu in 1968-1969 killed 1 million and the yearly seasonal flu results in anywhere from 5 to 15% of us getting ill; 250,000 to 500,000 die as a result. But these flu strains actually only resulted in a death ratio of less than 0.1%.

As it turned out, there was very little person to person spread of the avian flu. If there had been the results could have been catastrophic.

But the pigs had nothing to worry about; we did!

One of the outcomes of the avian H5N1 outbreak was fortuitous. When the "Swine flu" pandemic occurred in 2009-2010, the public health establishment and the medical community were considerably better prepared. The CDC summary is worth reading as it documents the steps taken to contain the virus; actually this was a flu strain that was transmitted from person to person and wasn't present in US pig herds.

The virus itself had genes from four different influenza virus sources, two from pigs, one from birds and one from a human flu virus. The CDC widely distributed kits to labs enabling them to identify the new viral strain. They and the World Health Organization (WHO) kept tabs on the numbers of cases of the new disease and WHO announced a global pandemic in June, 2009 .

A vaccine was developed with unusual speed and a preliminary target group of higher-risk individuals was identified; this consisted of 159 million people in the US. Vaccine safety was tested in various groups and the vaccine itself was administered starting in early October; by late December 2009 enough had been produced to allow vaccination of anyone wishing it.

The final results were impressive; less than two-thirds of a million people caught the virus and the death rate was 0.03%