Health and Medicine – Page 24

Open access medical records

Open access medicine Fancy being a case report for medical scientists to ponder? If your answer to that question is yes, then you probably carry a donor card, regularly give blood, and have already willed your body to medical science. If the answer was no, then read on, the following may persuade you to if not donate your remains then perhaps make yourself a case in point.

Medical case reports serve a vital role in medicine. Like those howto and self-help feature articles one sees in popular lifestyle magazines, they focus entirely on an individual patient, but at a slightly more technical level. Case studies provide unique insights into the rare side effects of new medications, early warning indicators of potential new diseases, unexpected associations between diseases or symptoms, and much more. Indeed, it was through case reports in the medical literature, that the earliest information on AIDS, Lyme disease and toxic shock syndrome emerged.

In recent years, however, economic and ethical pressures have led research journals to publish fewer and fewer medical case reports. The main pressure seems to be that such papers are of limited interest when read in isolation and more problematic from the publishers’ point of view are unlikely to be highly cited. Many research journals tout citation counts as a major selling point both to authors and subscribers, so poor-selling papers are unattractive to the marketing team.

The end result, is that a vast wealth of unique scientific data is simply lost.

Michael Kidd, Professor and Head of the Discipline of General Practice at the University of Sydney, hopes to change all that. He is founder of the open access (OA) Journal of Medical Case Reports. The OA approach taken by this journal means that medical case reports can find an audience regardless of citation concerns. By utilizing the OA publishing model, interesting case reports can reach the medical profession where previously they would simply sink without trace. With open access to this information, doctors can easily compare symptoms and treatments between patients and researchers and can sift through thousands of reports to formulate hypotheses and search for patterns and correlations. Who knows when the next AIDS or Lyme disease will emerge. Case reports might provide the first hints from the unfortunate “early adopters.”

Do heavy metal fans get skin cancer

Denim jacket As it is a holiday across the UK today, there is probably little need to warn Brits of the dangers of the sun’s rays, it’s usually so cold and wet, that the chances of frostbite and rust are much higher than sunburn. That said, summer is on its way and a paper in the latest edition of the Lancet medical journal warns that sunscreen and light cotton clothing are simply not enough to protect you from skin cancer caused by exposure to ultraviolet light from the sun.

Instead, the paper’s author suggest that anyone who dares to partake of the great outdoors should wear heavy cotton clothing such as denim, wool, or polyester, to block out those damaging rays. But, should this advice be well taken? Is the sun really to blame for the apparent increased incidence of skin cancer we hear reported or could it be that our car and desk bound sedentary lifestyles in which most people barely see the sun except on their foreign holidays are more to blame for compromising our immune systems and making us more susceptible to skin and various other forms of cancer.

We’ve covered this issue previously in Sciencebase, recent evidence points to a lack of vitamin D (manufactured in the skin during sunlight exposure) as being a much higher risk factor for various cancers than sun exposure itself.

The Lancet Review authored by dermatologist Stephan Lautenschlager of Triemli Hospital, in Zurich, Switzerland, analysed the various sun protection strategies used around the globe. “Wearing sun protective clothes and a hat and reducing sun exposure to a minimum should be preferred to sunscreens,” the team writes, “Often this solution is deemed to be unacceptable in our global, outdoor society, and sunscreens could become the predominant mode of sun protection for various societal reasons, for example healthiness of a tan, relaxation in the sun.”

The Review says that linen and loosely woven cotton represent less effective sun protection and that tightly woven, thick garments made of denim, wool or polyester offer the best protection; not exactly the kind of clothing anyone but heavy metal fans would want to wear on a scorching hot sunny day.

The paper points out that several studies have shown that sunscreen protects against acute UV skin damage and non-melanoma skin cancer, it is not known whether sunscreen stops melanoma developing. And, perhaps therein lies the rub, the connection between sunlight exposure and skin cancer itself is not as cut and dried as some commentators suggest.

“Suggesting wearing denim in hot weather is I think so stupid – it is very uncomfortable. Special clothing is not needed in the UK – on rare very hot days it is better simply to seek the shade – after some exposure to get your dose of D without burning, says Oliver Gillie of London-based lobby group Health Research Forum. He points out once more, that insufficient exposure to sunlight could be doing us more harm than good in terms of increasing cancer risk because of a lack of vitamin D.

“A link between heart disease and insufficient vitamin D is emerging,” he told Sciencebase, “and the National Heart Forum is interested in this aspect of the debate.” Given that until now the sunlight and skin cancer debate has essentially been a Cancer Research UK monopoly, it will be interesting to see how the heart charity approaches the issues.

There have been numerous other research developments that have not seen the media light of day. “There are links with infectious disease,” adds Gillie, “Vitamin D is important for maintaining immune system resistance a fact well-known to those treating tuberculosis a century ago and well before the advent of antibiotics.”

Cancer Research UK says that 90% of melanoma is caused by sun exposure. “This is a very contentious figure,” Gillie points out, “and is disputed.” He adds that it could be that as few as one in ten melanoma cases are caused by sun exposure. “Poor immunity is a big factor in melanoma and people who are on immune suppressing drugs e.g. transplant patients are at high risk,” he says.

Such observations certainly cloud the picture of sun exposure as the big skin cancer killer. He also points out that purported mechanisms for DNA damage and thence skin cancer formation based on the photochemistry of DNA itself no longer stack up because it is now known that melanin, the pigment that gives rise to a tan is a protective agent against the very mutagenic molecules thought to form on sun exposure. Indeed, Raymond Barnhill and colleagues writing in the Journal of the National Cancer Institute (2005, 97, 195-199) found that people with melanoma survive longer if they have more sun exposure. This is doubly ironic in that post-treatment melanoma patients are usually advised to stay out of the sun.

If the British weather is kind for once this Bank Holiday Monday, it will pour sunshine down on all of us. So, leave the denim at home, unless you are a heavy metal fan, and make sure your icecream doesn’t melt while you are sunning yourself.

Should you worry about HRT and cancer?

Menopausal woman A female friend of a friend started on hormone replacement therapy (to treat quite severe early postmenopausal symptoms, and on the advice of her GP to reduce the risk of osteoporosis). The symptoms have all but been relieved (although it’s difficult to separate out the effects of the HRT hormones themselves from the phytoestrogens she imbibes from soy milk and other related foods).

Either way, the recent Lancet paper, which received lots of media attention, got her all hot and bothered. She’s an earlier finisher, and is likely to be on HRT for ten years or so, is that going to mean she will get ovarian cancer. The tabloid hype surrounding the paper would seem to suggest so, but as with all statistical health studies that get pounced on by the media it’s worth taking a closer look.

Interpreting the results and scaling up to whole number women, as opposed to fractional women, over 5 years, ovarian cancer incidence for those who have never used HRT was 26 per 10,000. It was 30 per 10,000 for HRT users.

The researchers conclude that, “Women who use HRT are at an increased risk of ovarian cancer. Since 1991, use of previous has resulted in 72 additional cancers per year and 55 additional deaths in the UK.” Their results are based on the million women study, in which 500,000 were HRT and 500,000 were not.

Of course, ovarian cancer is the fourth most common cancer in women in the UK, with some 6700 developing the malignancy and 4600 dying from it every year. The high incidence of deaths is presumably down to the hidden nature of this form of cancer, which is often not detected until it has reached a lethal stage. 72 additional cancers and 55 additional deaths is a significant but not an enormous increase.

The researchers also add that, “In total, ovarian, endometrial, and breast cancer account for 39% of all cancers registered in women in the UK.1 and 2 The total incidence of these three cancers in the study population is 63% higher in current users of HRT than in never users (31 vs 19 per 1000 over 5 years, figure 6). Thus, when ovarian, endometrial, and breast cancer are taken together, use of HRT results in a material increase in the incidence of these common cancers.”

But, these are risk factors and there is simply no way of making any kind of prediction, with current medical knowledge, of whether or not a particular woman on HRT will suffer any form of cancer because of the HRT drugs she is taking. The researchers mention that as HRT use has declined in the US (partly because of the negative publicity it receives), we are also now seeing falling breast cancer rates there.

According to the author of the paper, Valerie Beral of Cancer Research UK, “It is a small but significant risk. It’s more an issue for women to think about how much they want to take HRT to relieve their symptoms against the known risks.”

However, it’s not all about hot sweats and sexual libido, as life expectancy rises in general and the aspirations of older people for a happy and active retirement rises concomitantly, it will be interesting to see whether a few less cancers will be offset by a rise in osteoporosis incidence and the other “side-effects” of the menopause (particularly early onset menopause).

An elderly neighbour of mine has been in and out of hospital with bone density issues and fractures repeatedly and at one point suffered a potentially lethal hospital-acquired MRSA (multiple-resistant Staphylococcus aureus) infection as a result. To my mind, she would most likely not have suffered in this way had she taken HRT during the early menopause. But, equally there is also the thought that had she died of cancer sooner than the osteoporosis kicked in, she would not have suffered bone density problems later in life either.

For every statistic, a counter statistic can be found and when the overall risks are very small it is difficult for the public, the media, and even the medical scientists to know for sure which way to push the agenda.

One burger could kill

Burger and fries Grandma always said, “Everything in moderation”, but then she always used to take her teeth out to eat soup, so what does she know? Apparently, even moderation can be dangerous, particularly when it comes to high fat food.

Tavis Campbell and colleagues at the University of Calgary have found that just one high-fat meal, a fast-food breakfast for instance, makes you prone to suffer the physical consequences of stress compared with someone eating a low-fat meal.

The team looked at the stress responses of two groups of students: fifteen students were fed a fatty breakfast meal (42 g fat) from a burger bar while the second group of fifteen got to dine on dry cereal with low-fat milk, cereal bars and non-fat yogurt (1 g fat). Both meals had the same number of calories and the low-fat breakfast included supplements to balance it for sodium and potassium, but the total fat content was very different.

Two hours later, the researchers carried out standard physical and mental stress tests and recorded the students’ cardiovascular responses. They performed a mathematical test designed to be stressful, completed a public speaking exercise about something emotionally provocative, held an arm in ice water, and had a blood pressure cuff inflated around an arm, which gradually causes a dull ache.

Regardless of the task, greater CV reactivity was seen in the high-fat group, including raised blood pressure, heart rate and blood vessel resistance. “What’s really shocking is that this is just one meal,” says Campbell.

“It’s been well documented that a high-fat diet leads to atherosclerosis and high blood pressure, and that exaggerated and prolonged cardiovascular responses to stress are associated with high blood pressure in the future,” he says, “So when we learn that even a single, high-fat meal can make you more reactive to stress, it’s cause for concern because it suggests a new and damaging way that a high-fat diet affects cardiovascular function.”

Thankfully, it is not all bad news. Campbell says more research is needed to fully understand how the mechanisms work. “Telling people to never eat something is probably not a good way to promote a better diet,” he says. “At the same time we do have an epidemic of obesity in North America and it’s important that people try to make informed choices.”

Science always hedges its bets in this way. If the argument were about whether to vote left or right, the politicians and lobbyists would make full-on assertions as to even the acute effects of a one-off high-fat vote. Yes, Campbell’s team has only carried out a small preliminary trial, and perhaps underfed and stressed students are not the best control group, but there findings do hint at yet another reason why we should side-step a high-fat diet.

The case is essentially closed on cigarettes in this sense, but individuals can make their own choice. Is it not about time, that the health message were made more forcefully. Maybe one burger is not going to kill you, but some people spend a fortune on finding ways to reduce stress and warding off the effects of aging, if even an occasional high-fat meal inverts all that effort, then perhaps it is time burgers carried a health warning too.

Details of the study are published today in the Journal of Nutrition, 2007, 137, 935-939

Organic Kiwi Fruit

Organic kiwi fruit Could the claims of the “organic” farming movement be true after all? According to an international team who have analysed the antioxidant, mineral, and nitrate composition of kiwifruit, yes. Their findings published in the Journal of the Science of Food and Agriculture would suggest that growing the fuzzy green fruit using so-called organic principles leads to a higher content of health-promoting factors than those grown using conventional methods.

I asked team leader Adel Kader of the University of California, Davis, about his reasoning. “Most differences in composition between conventionally grown and organically grown fruits depend on differences in inputs,” he told us. These inputs include differences in fertilizers added and so results vary considerably from one study to the next, “In our kiwifruit study, the grower added more fertilizers to the organic kiwifruit plants than to the conventional ones and that is the reason for the higher mineral contents of the organic fruits,” he adds, “The one exception is phenolic [antioxidant] content, which has been shown in our study and in several other studies on a range of crops to be higher in organic than in conventional fruits.”

Kader believes that the difference is most likely due to the fruit having to survive against pests in the absence of synthetic pesticides. “Conventional agriculture practices utilize levels of pesticides that can result in a disruption of phenolic metabolites in the plant,” he says, “which have a protective role in plant defense mechanisms.” His hunch is further corroborated by the organic kiwifruit having thicker skins as well as the higher antioxidant activity which is thought to be a natural by-product of stress. He has a simple piece of advice for those dithering over whether to tuck into the fuzzy fruit: “My advice is that people eat more fruits regardless of whether they are conventionally or organically produced,” he told Sciencebase. More on this story in SpectroscopyNOW this week.

Obesity Gene

Obesity overweight Today’s claims in the media about the recently discovered obesity gene are at best overwrought and at worst downright dangerous. A vast study involving more than twenty research centres across the UK has allegedly demonstrated that almost one fifth of us carry a variant of the gene known as FTO that predisposes us to obesity or overweight.

According to the researchers, “Obesity is a serious international health problem that increases the risk of several common diseases.” Fair comment. They add that, “The genetic factors predisposing to obesity are poorly understood.” Another fair comment.

They then report that while carrying out a genome-wide search for type 2 diabetes susceptibility genes among 13 groups of almost 40000 participants they have identified a common variant in the FTO gene that predisposes to diabetes through an effect on body mass index (BMI).

Additionally, the team reports that there is a cumulative, or additive, association of the variant with BMI. They found that 16% of the adults with the risky genetics weighed about 3 kilograms more than the others and were almost twice as likely to be obese, when compared to people without the risk allele. Moreover, the team says that they observe this genetic risk factor in individuals age 7 years and older and say that it reflects a specific increase in fat mass.

But, all this talk of obesity being down to genes will provide many individuals with an excuse along the lines of “it’s my glands”, which has become something of a serious cliche for some people who simply refuse to reduce the calorie intake and to add serious amounts of exercise to their daily routine.

The politics of obesity aside, I contacted metabolic expert Jeremy Nicholson of Imperial College London who recently discovered that calorie restriction in dogs extends life, reduces the risk of diabetes and metabolic disorders, and could be due to a change in the behaviour of microbes in the gut. He is less than impressed with the response of the media to the Science paper on FTO. “Basically, no amount of genetics can explain how humans have got fat so fast,” he told me. I would have to agree, genetics has long-term effects one usually does not see major changes in body function and form happening across a single generation.

So, might there be an alternative explanation for the apparent obesity epidemic in the developed world? Nicholson thinks so. “Changes in the gut microbes and caloric bioavailability probably could be the explanation,” he says. If we are suffering severe disturbances in the profile of gut bacteria – either they have changed behaviour or the species have changed – then those heading for overweight or who are already obese could be absorbing far more calories even from the same amount of food because of it.

Liposuction, like Vaser, Smartlipo and laser liposuction is one option, but could a dose of live yogurt or an antibiotic regimen be the solution to obesity? We are only just starting the hors d’heuvre when it comes to understanding the interplay between our bodies and microbes. Much more work into metabolism and the role of the guy microflora needs to be done before we can cast aside obesity as yet another genetic construct and so abandon sufferers to the realm of the untreatable.

Nicholson explains that the microflora in our gut are laid down in infancy and there is not a lot we can do about that. However, he says, “The real secret is eating a lot of beans and pulses (lentils etc) – lots of them every day, they keep the lower gut microbes very happy and the products of their
breakdown (catabolism) do not cause diabetes.” Nicholson laments that the windy side-effects of such a diet are far less malign than the problems associated with a diet deficient in beans and pulses.

Genetics, microbes, and beans aside, Nicholson has what I think has to be the final word on the debate: “Even genes and bugs added together still fade into insignificance if you sit on your butt all day eating pork rinds – you will get fat but its not genetic!”

It’s a dog’s life

Puppy dog Cutting out the French fries, burgers, chips, candy, beer, soda, and other delicious yet largely non-nutritious food and drink from your diet is generally a good idea. One of the reasons, health experts suspect, is that somehow a reduced-calorie diet leads to a longer life. Now, researchers at Imperial College London have looked at a dog’s life and discovered why dietary restriction could lead to a longer life.

Jeremy Nicholson and colleagues followed 12 “pairs” of dogs in which one partner in each pair was given 25% less food than the other. Nicholson and his colleagues found that the dogs who had less food lived almost 2 years longer (that perhaps equates to between 10 and 14 years). They also found that those dogs suffered less diabetes and osteoarthritis, and were older on average when plagued by the common diseases of old age.

But, why?

The scientists believe that differences in the populations of microbes in the dogs’ guts could partly explain the metabolic differences. The dogs that were not on a restricted diet had increased levels of potentially unhealthy aliphatic amines in their urine, the team found. The presence of higher levels of these compounds indicate reduced levels of choline, the compound essential for metabolizing fat. Such a microbial profile has, in other studies, been associated with the development of insulin resistance and obesity in humans.

Nicholson explains: “This fascinating study was primarily focused on trying to find optimized nutritional regimes to keep pet animals such as dogs healthy and as long-lived as possible. However these types of life-long studies can help us understand human diseases and aging as well, and that is the added bonus of being able to do long-term non-invasive metabolic monitoring.”

So, might this study be applicable to humans and should we too be cutting down on our doggy treats and Pedigree Chum? Potentially, yes. Despite superficial appearances and the sometimes disgusting things dogs choose to eat, the flora and fauna of our guts are very similar. It all depends on whether cutting your burger and soda intake by 25% is worth it for those extra 10 to 14 dog years.

Details of the study are published today in the Journal of Proteome Research. The paper is one in a special issue of the journal in “Metabolomics, Metabonomics, and Metabolic Profiling in Complex Organisms: The Portals to “Real-Life” Systems Biology”.

Choline chemical structure
InChI=1/C5H14NO/c1-6(2,3)4-5-7/h7H,4-5H2,1-3H3/q+1

In totally, unrelated canine news, scientists from the University of Utah and seven other institutions have identified a piece of doggy DNA that reduces the activity of a growth gene, ensuring that small breeds stay small. More on that via Newswise.

Workout limits

Do you workout hard? Is “no pain, no gain” your exercise ethos? Do you feel like you are not getting the fitness results you expect? Your brain could be to blame.

Yagesh Bhambhani and Rohit Malik of the Faculty of Rehabilitation Medicine, at the University of Alberta, Edmonton, Canada and Swapan Mookerjee of Bloomsburg University, Bloomsburg, Pennsylvania, USA, have monitored the oxygen levels of blood flowing in the brains of healthy volunteers while they worked out using near infrared spectroscopy.

NIRS can evaluate changes in blood volume and oxygen levels in the brain while people exercise by measuring the absorption of this form of electromagnetic radiation by the blood, which varies depending on how much oxygen is present.

The team has found that even if you are healthy, there could be an upper limit on just how hard you can push yourself, because brain activity begins to be affected detrimentally as you push harder and harder.

The study watched blood flow and volume as well as measuring carbon dioxide breathed out during an incremental exercise test. In the tests, exercise intensity is gradually stepped up until the volunteers reach exhaustion and must stop. The observed fall off in carbon dioxide levels coincided with decreased blood flow to the brain, which affects exercise capacity, the researchers say.

You can find out more about the science behind the exercise threshold here. Of course, if you are not pushing your exercise regime to the limits, then you probably have nothing to worry about. More to the point, the research is aimed at fine tuning finely tuned athletes and others, not providing the sedantary or mediocre with an excuse to give up half way through their treadmill cycle. (Ahem, mentioning no names…)

Beating Heart Disease with Vitamin B Drugs

Niacin is involved in the metabolism or carbohydrates, fats and proteins, but at high dosage it can increase HDL more than a third and reduce levels of “artery-clogging” triglycerides by half.

Graeme Semple of Arena Pharmaceuticals, San Diego, reports how new drugs that raise high-density lipoproteins, so-called good cholesterol might be developed by following the lead of familiar B vitamin, niacin.

Researchers at Arena and elsewhere are trying to develop new drugs that are even more effective than niacin and so could have greater potential to protect at-risk people against heart attacks and stroke. Semple discusses the latest developments at the ACS annual meeting today.

You can read more about the biochemistry of niacin and LDL cholesterol in Sciencebase.

InChI=1/C6H5NO2/c8-6(9)5-2-1-3-7-4-5/h1-4H,(H,8,9)/f/h8H

Magnetizing a Baby

It is possible to magnetize a baby with a few drops of water, some ordinary sugar and a teether. It’s all down to changes that take place in the brain when the baby tastes the sugar.

Neal Barnard MD, founder of the Physicians Committee for Responsible Medicine (PCRM), explains the process. Of course it’s not really magnetization, it’s the release of opiates in the brain, natural versions of morphine and heroin, that make us feel good. Barnard discusses the science underlying food addictions. Personal willpower is not necessarily to blame, chocolate, cheese, meat, and sugar all release these opioids. substances. Dr. Barnard also discusses how industry, aided by government, exploits these natural cravings, pushing us to eat more and more unhealthy foods. He suggests that a purely plant-based (vegan) diet is the solution to avoid many of these problems.

He points out how cheese and other dairy products contain natural compounds closely related to morphine, perhaps as a natural bonding chemical to ensure suckling mammals “enjoy” the suckling process. The presence of tiny quantities of these compounds in so many foods could explain why dairy products, chocolate, wheat, meat, nuts, onions, corn, tomatoes, onions, bananas, citrus fruits etc are common dietary triggers of migraine, for instance, users are simply overdosing on the opiates and then suffering withdrawal symptoms. And, as to cardiovascular disease, stroke, and heart attack…cardiologists know that if a man in his fifties presents with impotence, there is a one in four chance that he will have a heart attack or stroke within two years. Barnard blames our addiction to meat and even got cattle ranchers in the mid-west to prick up their ears when he relayed that fact and had them asking for his tofu recipes and tips on cooking brown rice.

Anyway, it’s a long video (40 minutes) but makes very interesting viewing.