Tag Archives: human health

Cell Aging and Limits Due to Telomeres

When cells divide the process fails to copy DNA all the way to the end. Telomeres are are the end of DNA strands, as essentially a buffer of material that won’t cause information to be lost when part of the telomere isn’t copied. As DNA is copied, as new cells are created, the length of telomeres at the end is reduced. Once the telomeres are gone the cell will no longer divide.

The 2009 Nobel Prize in Physiology or Medicine went to 3 scientists for discovering how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation. The Nobel Laureates have shown that the solution is to be found in the ends of the chromosomes – the telomeres – and in an enzyme that forms them – telomerase.

There is some debate over the benefit of the mechanism of cells not dividing do to lack of telomere. This can prevent cancerous cells from replicating (once they replicate to the extent that the necessary telomere buffer is gone). It is also seen that as telomeres get shorter the cells become more likely to become cancerous.

Cancer also can stimulate the production of telomerase which can stop telomeres from getting shorter as cells divide and thus allow the cancer cells to keep dividing (thus producing more cancer cell and increasing the amount of cancerous cells). Using telomerase to allow health cells to avoid the limits of division is being researched.

Are Telomeres the Key to Aging and Cancer? (University of Utah)

An enzyme named telomerase adds bases to the ends of telomeres. In young cells, telomerase keeps telomeres from wearing down too much. But as cells divide repeatedly, there is not enough telomerase, so the telomeres grow shorter and the cells age.
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Cells normally can divide only about 50 to 70 times, with telomeres getting progressively shorter until the cells become senescent, die or sustain genetic damage that can cause cancer.
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shorter telomeres are associated with shorter lives. Among people older than 60, those with shorter telomeres were three times more likely to die from heart disease and eight times more likely to die from infectious disease.

While telomere shortening has been linked to the aging process, it is not yet known whether shorter telomeres are just a sign of aging – like gray hair – or actually contribute to aging.

CDC Again Stresses Urgent Need to Adjust Practices or Pay a Steep Price

Untreatable and hard-to-treat infections from Carbapenem-resistant Enterobacteriaceae (CRE) germs are on the rise among patients in medical facilities. CRE germs have become resistant to all or nearly all the antibiotics we have today. Types of CRE include Klebsiella pneumoniae Carbapenemase (KPC) and New Delhi metallo-beta-lactamase (NDM). By following the United States Center for Disease Control (CDC) guidelines, we can slow the penetration of CRE infections in hospitals and other medical facilities and potentially spread to otherwise healthy people outside of medical facilities.

The CDC has worked with hospitals to successfully apply these measures. The CDC worked with Florida to stop a year-long CRE outbreak in a long-term acute care hospital. With the improved use of CDC recommendations (such as educating staff; dedicating staff, rooms, and equipment to patients with CRE; and improving use of gloves and gowns) the percentage of patients who got CRE at the facility dropped from 44% to 0.

One travesty has been how poorly health care professionals have been about prescribe antibiotics wisely We need to improve and follow CDC antibiotics guidelines (stop the overuse of antibiotics) and use culture results (for patients undergoing treatment) to modify prescriptions, if needed. Antibiotic overuse contributes to the growing problems of Clostridium difficile (c-diff) infection and antibiotic resistance in healthcare facilities. Studies indicate that nearly 50% of antimicrobial use in hospitals is unnecessary or inappropriate (per CDC web site).

Israel decreased CRE infection rates in all 27 of its hospitals by more than 70% in one year with a coordinated prevention program. The USA is at a critical time in which CRE infections could be controlled if addressed in a rapid, coordinated, and consistent effort by doctors, nurses, lab staff, medical facility leadership, health departments/states, policy makers, and the federal government.

As I have been saying for years the damage we are creating due to our actions around the use and abuse of antibiotics is likely to kill tens of thousands, or more people. Because the deaths are delayed and often not dramatic we have continued dangerous practices for years when we know better. It is a shame we are condemning so many to increased risks. The CDC, and others, are doing good work, unfortunately too much bad work is continuing in the face of evidence of how dangerous that is.

People are Superorganisms With Microbiomes of Thousands of Species

In a recent article in National Geographic Carl Zimmer has again done a good job of explaining the complex interaction between our bodies and the bacteria and microbes that make us sick, and keep us healthy.

The damage done by our indiscriminate use of antibiotics is not just the long term resistance that we create in bacteria (making the future more dangerous for people) that I have written about numerous times but it also endangers the person taking the anti-biotics in the short term. Sometimes the other damage is a tradeoff that should be accepted. But far too often we ignore the damage taking antibiotics too often does.

When You Swallow A Grenade

While antibiotics can discriminate between us and them, however, they can’t discriminate between them and them–between the bacteria that are making us sick and then ones we carry when we’re healthy. When we take a pill of vancomycin, it’s like swallowing a grenade. It may kill our enemy, but it kills a lot of bystanders, too.
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If you think of the human genome as all the genes it takes to run a human body, the 20,000 protein-coding genes found in our own DNA are not enough. We are a superorganism that deploys as many as 20 million genes.
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Before he started taking antibiotics, the scientists identified 41 species in a stool sample. By day 11, they only found 13. Six weeks after the antibiotics, the man was back up to 38 species. But the species he carried six weeks after the antibiotics did not represent that same kind of diversity he had before he took them. A number of major groups of bacteria were still missing.
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They found that children who took antibiotics were at greater risk of developing inflammatory bowel disease later in life. The more antibiotics they took, the greater the risk. Similar studies have found a potential link to asthma as well.

The human body contains trillions of microorganisms — outnumbering human cells by 10 to 1. Because of their small size, however, microorganisms make up only about 1% to 3% of the body’s mass, but play a vital role in human health.

Where doctors had previously isolated only a few hundred bacterial species from the body, Human Microbiome Project (HMP) researchers now calculate that more than 10,000 microbial species occupy the human ecosystem. Moreover, researchers calculate that they have identified between 81% and 99% of all microorganismal genera in healthy adults.

“Humans don’t have all the enzymes we need to digest our own diet,” said Lita Proctor, Ph.D., NHGRI’s HMP program manager. “Microbes in the gut break down many of the proteins, lipids and carbohydrates in our diet into nutrients that we can then absorb. Moreover, the microbes produce beneficial compounds, like vitamins and anti-inflammatories that our genome cannot produce.” Anti-inflammatories are compounds that regulate some of the immune system’s response to disease, such as swelling.

“Enabling disease-specific studies is the whole point of the Human Microbiome Project,” said Barbara MethÃ©, Ph.D., of the J. Craig Venter Institute, Rockville, MD, and lead co-author of the Nature paper on the framework for current and future human microbiome research. “Now that we understand what the normal human microbiome looks like, we should be able to understand how changes in the microbiome are associated with, or even cause, illnesses.”

Read the full NIH press release on the normal bacterial makeup of the body

How to Walk on Ice

infographic explaining how to walk on ice - walk like a penguin

Infographic by Tablet. Falling on ice leads to many injuries and even 60 deaths a year in the USA (about the number that will die due to tornados). The graphic encourages thinking like a penguin. Penguins walk well on ice (in some ways) and they also fall well.

Seeking to keep your weight well supported (short strides) is wise (and sliding instead of picking up your feet can help). Falling well is also important. It is basic physics, you want to lower your center of gravity if you are start to slip and avoid any excessive force (so sliding is better than trying to stick out your hand and support all your weight). The elderly are especially susceptible to injuries – avoiding taking direct shocks to the wrist, knees or hips is wise). It does seem kind of silly to learn how to fall but it is very helpful in avoiding injuries.

On sidewalks if you are going to fall and there is snow piled up off the sidewalk, falling into the pile of snow may well be softer than falling directly onto the sidewalk.

On ice you have lower friction so strategies that require friction are not useful – quick moves often rely on very sturdy bases (which are based on the friction of our shoe on for example concrete [which normally is good – though business shoes are not very good] and on ice [where it is very poor – sliding and gradual moves are better]).

Quick Webcast With a Few Interesting Science Facts

Interesting facts: I didn’t know that we require 13 minerals or that alcoholic beverages contain amounts of all the minerals we need. An amazing fact: the average person walks the equivalent of 3 times around the earth in a lifetime.

The minerals we need (and the recommended daily amount)

Calcium – 1,200 mg
Magnesium – 320 mg
Phosphorus – 700 mg
Potassium – 4.7 g
Sodium – ?
Chloride?

trace amounts needed
Cobalt (as Vitamin B12) – 2.4 mcg
Copper – 1,156 mcg
Iodine – 150 mcg
Iron – 8 mg
Manganese – 1.8 mg
Niacin – 14 mg
Riboflavin – 1.1 mg
Selenium – 55 mcg
Thiamin – 1.1 mg
Zinc – 8 mg
Chromium?, Molybdenum? Fluoride?

Frankly, in my quick looks around the internet I am not sure what they base the claim we need only 13 minerals on. It seems we need trace amounts of more minerals – did they just ignore those not in alcohol?

I couldn’t find good sources confirming just what minerals are needed. Many list some minerals but don’t list others. I am not really sure what the answer is. I am glad I seem to somehow get whatever I need just by eating somewhat healthfully. It is pretty cool we get these things that way. Of course if we didn’t our ancestors wouldn’t have survived to create descendants that finally became us – as they had a much harder time than me (who can just go the restaurant and grocery store and get all sorts of wonderful food).

How Corn Syrup Might Be Making Us Fat

How Corn Syrup Might Be Making Us Hungry–and Fat by Katherine Harmon

…Glucose lowered the activity of the hypothalamus but fructose actually prompted a small spike to this area. As might be expected from these results, the glucose drink alone increased the feelings of fullness reported by volunteers, which indicates that they would be less likely to consume more calories after having something sweetened with glucose than something sweetened with more fructose.

Fructose and glucose look similar molecularly, but fructose is metabolized differently by the body and prompts the body to secrete less insulin than does glucose (insulin plays a role in telling the body to feel full and in dulling the reward the body gets from food). Fructose also fails to reduce the amount of circulating ghrelin (a hunger-signaling hormone) as much as glucose does. (Animal studies have shown that fructose can, indeed, cross the blood-brain barrier and be metabolized in the hypothalamus.) Previous studies have shown that this effect was pronounced in animal models…

Most of the science indicates calories consumed is by far the dominant factor in weight gain. Different foods with the same calories can affect how hungry you feel. Thus the biggest factor in reducing weight gain seems to be reducing calories and one way to help is to eat food that leaves you feeling full and avoid foods that don’t.

The science is not completely clear though on whether certain diets can have a significant affect above and beyond calorie levels. I am skeptical of such claims, however. There are concerns beyond calories for healthy eating – getting a well balanced diet is important.

Healthy physical activity is also important. Burning off calories with exercise allows more consumption without weight gain. And exercise is important for health not just to avoid gaining weight.

Cancer Risks From Our Food

comic showing the dangers of drawing false conclusion based on statistical significance

Randall Munroe illustrates RA Fisher’s point that you must think to draw reasonable conclusions from data. Click the image to see the full xkcd comic.

Pretty much everything you eat is associated with cancer. Don’t worry about it. by Sarah Kliff

The changes in cancer risk were all over the map: 39 percent found an increased risk, 33 percent found a decreased risk and 23 percent showed no clear evidence either way.
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The vast majority of those studies, Schoenfeld and Ioannidis found, showed really weak associations between the ingredient at hand and cancer risk. A full 80 percent of the studies had shown statistical relationships that were “weak or nominally significant,” as measured by the study’s P-values. Seventy-five percent of the studies purporting to show a higher cancer risk fell into this category, as did 76 percent of those showing a lower cancer risk.

Sadly the evidence is often not very compelling but creates uncertainly in the public. Poorly communicated results and scientific illiteracy (both from publishers and the public) leads to more confusion than is necessary. Even with well done studies, good communication and a scientifically literate population nutrition and human health conclusion are more often questionable than they are clear.

Drug Company Funding Taints Published Medical Research

Science provide the opportunity for us to achieve great benefits for society. However, especially in medical research money can make what are already very difficult judgments even less reliable. Add that to a very poor understanding of science in those we elect and you have a dangerous combination. That combination is one of the largest risks we face and need to manage better. I wish we would elect people with a less pitiful appreciation for science but that doesn’t seem likely. That makes doing a better job of managing the conflicts of interest money puts into our current medical research a top priority.

How Drug Company Money Is Undermining Science by Charles Seife

In the past few years the pharmaceutical industry has come up with many ways to funnel large sums of money—enough sometimes to put a child through college—into the pockets of independent medical researchers who are doing work that bears, directly or indirectly, on the drugs these firms are making and marketing. The problem is not just with the drug companies and the researchers but with the whole system—the granting institutions, the research labs, the journals, the professional societies, and so forth. No one is providing the checks and balances necessary to avoid conflicts.
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Peer-reviewed journals are littered with studies showing how drug industry money is subtly undermining scientific objectivity. A 2009 study in Cancer showed that participants somehow survived longer when a study’s authors had conflicts of interest than when the authors were clean. A 1998 study in the New England Journal of Medicine found a “strong association” between researchers’ conclusions about the safety of calcium channel blockers, a class of drugs used to reduce blood pressure, and their financial relationships with the firms producing the drugs.

Most of those in the system have an interest in minimizing an effort to clean this up. It is just more work they don’t want to do. Or it goes directly against their interest (drug companies that want to achieve favorable opinions by buying influence). The main political message in the USA for a couple decades has been to reduce regulation. Allowing research that is tainted because you find regulation politically undesirable is a bad idea. People that understand science and how complex medical research is appreciate this.

Sadly when we elect people that by and large are scientifically illiterate they don’t understand the risks of the dangerous practices they allow. Even if they were scientifically illiterate but understood their ignorance they could do a decent job by getting scientific consultation from experts but they don’t (to an extent they listen to the scientists that those that give them lots of money tell them to which does help make sure those giving the politicians cash have their interests served but it is not a good way to create policy with the necessary scientific thinking needed today).

Solar Powered Water Jug to Purify Drinking Water

Deepika Kurup, a 14-year-old New York student, won the Discovery Education 3M Young Scientist Challenge for her invention of a solar-powered water jug that changes dirty water into purified drinking water. She won the top prize of $25,000.

During “the 5 minutes of my presentation 15 children have died from lack of clean drinking water.”

I am thankful we have kids like this to create solutions for us that will make the world a better place. We rely on hundreds of thousands of such people to use science and engineering methods to benefit society.

Smoking Bans at Work and Public Places Result in Significant Drops in Hospitalization for Heart Attacks, Strokes and Asthma.

Laws that end smoking at work and other public places result in significantly fewer hospitalizations for heart attacks, strokes, asthma and other respiratory conditions, a new UCSF analysis has found.

The research provides evidence that smoke-free laws that cover workplaces, restaurants and bars have the biggest impacts on hospitalizations, reduce health care costs and also raise quality of life, the researchers said. The research is published in closed science journal; for an “association” (when you act as though your focus is just growing your income I have trouble seeing the claim for being an association as legitimate) to do that is particularly pitiful. Adding to the sad commentary on the lack of respect for open scient this is research done by a “public” university with grants from the federal government. So sad how little some that should care about science do when it conflicts with their outdated notions of how to publicize research. We really should not tolerate such behavior.

“The public, health professionals, and policy makers need to understand that including exemptions and loopholes in legislation — such as exempting casinos — condemns more people to end up in emergency rooms,” said senior author Stanton A. Glantz, UCSF professor of medicine and director of the Center for Tobacco Control Research and Education at UCSF. “These unnecessary hospitalizations are the real cost of failing to enact comprehensive smoke-free legislation,” he said.

The inquiry consisted of a meta-analysis of 45 studies published prior to Nov. 30, 2011. Altogether, the research covered 33 different smoke-free-laws in cities and states around the United States as well as several countries, including New Zealand and Germany. The laws variously prohibit smoking in such public spots as restaurants, bars, and the workplace.

The authors found that comprehensive smoke-free laws were followed rapidly by significantly lower rates of hospital admissions than before the laws went into force:

A 15% drop in heart attack hospitalizations;
A 16% drop in stroke hospitalizations;
A 24% drop in hospitalizations for respiratory diseases including asthma and chronic obstructive pulmonary disease.

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