Skip to content

Author: Sima

Published on

Several interesting bacteria studies. Who knew that dental caries (tooth decay that causes cavities) is contagious? From Science Daily:

Bacteria can linger on airplane surfaces for days

Disease-causing bacteria can linger on surfaces commonly found in airplane cabins for days, even up to a week, according to research. In order for disease-causing bacteria to be transmitted from a cabin surface to a person, it must survive the environmental conditions in the airplane. In this study, MRSA lasted longest (168 hours) on material from the seat-back pocket while E. coli O157:H7 survived longest (96 hours) on the material from the armrest.

From Science Daily: Cavities are contagious, research shows

Dental caries, commonly known as tooth decay, is the single most common chronic childhood disease. In fact, it is an infectious disease, new research demonstrates. Mothers with cavities can transmit caries-producing oral bacteria to their babies when they clean pacifiers by sticking them in their own mouths or by sharing spoons. Parents should make their own oral health care a priority in order to help their children stay healthy.

From Science Daily: Physicians' stethoscopes more contaminated than palms of their hands

Although healthcare workers' hands are the main source of bacterial transmission in hospitals, physicians' stethoscopes appear to play a role. To explore this question, investigators assessed the level of bacterial contamination on physicians' hands and stethoscopes following a single physical examination. Two parts of the stethoscope (the tube and diaphragm) and four regions of the physician's hands (back, fingertips, and thenar and hypothenar eminences) were measured for the total number of bacteria present in a new study. The stethoscope's diaphragm was more contaminated than all regions of the physician's hand except the fingertips. Further, the tube of the stethoscope was more heavily contaminated than the back of the physician's hand.

Published on

An exciting research study which finds that it is normal for bacteria to live in the bladders of healthy women, and that urine is not sterile. After further studies on the microbial communities in the bladder, perhaps bacterial treatments for various urinary problems? From Science Daily:

Study debunks common myth that urine is sterile: Bacterial differences found in urine of healthy women and women with overactive bladder

Bacteria live in the bladders of healthy women, discrediting the common belief that normal urine is sterile. This study also revealed that bladder bacteria in healthy women differ from the bladder bacteria in women affected by overactive bladder (OAB), which causes a sudden need to urinate.

Approximately 15 percent of women suffer from OAB and yet an estimated 40 -- 50 percent do not respond to conventional treatments. One possible explanation for the lack of response to medication may be the bacteria present in these women.

"If we can determine that certain bacteria cause OAB symptoms, we may be able to better identify those at risk for this condition and more effectively treat them," said Alan Wolfe, PhD, co-investigator and professor of Microbiology and Immunology, SSOM.

This study evaluated urine specimens of 90 women with and without OAB symptoms. Urine samples were collected through a catheter and analyzed using an expanded quantitative urine culture (EQUC) technique. This EQUC technique was able to find bacteria that are not identified by the standard urine culture techniques typically used to diagnose urinary tract syndromes.

Loyola researchers now plan to determine which bacteria in the bladder are helpful and which are harmful. They also will look at how these bacteria interact with each other and with their host, and how we can use this information to help patients. 

Published on

Moderate levels of exercise seems to have tremendous benefits for everyone, but there are downsides to being an extreme exerciser.  From Science Daily:

Elderly men with high blood pressure lower death risk with moderate fitness

Elderly men with high blood pressure can lower their risk of death with even moderate levels of fitness. "This level of fitness is achievable by most elderly individuals engaging in a brisk walk of 20 to 40 minutes, most days of the week," said Charles Faselis, M.D., lead author of the study.

For the study, researchers assessed the fitness status of 2,153 men, aged 70 years and older with high blood pressure by a standard treadmill exercise test. Researchers applied the international units used to measure fitness, called metabolic equivalents (METs), to determine the men's peak fitness levels. After an average follow-up of nine years, researchers found that the risk of death was 11 percent lower for every one-MET increase in exercise capacity.

"For every 100 people who died in the least-fit category, 82 died in the low-fit, 64 in the moderate-fit and 52 in the high-fit categories," Kokkinos said. "The death rate is cut in half for those in the highest fitness category."

Too much exercise also has negatives for men. From Medical Xpress:

Too much prolonged high-intensity exercise risks heart health

Overdosing on high intensity exercise may actually increase the risk of death from a heart attack or stroke in those with existing heart disease, suggests German research published online in the journal Heart.

Similarly, a second Swedish study in the journal suggests that young men undertaking endurance exercise for more than five hours a week may increase their risk of developing an irregular heart rhythm in later life.

Both sets of findings indicate a J-shaped curve for the health benefits of exercise... And they describe "a similar U-shaped or reverse J-shaped pattern for the dose-response effect of exercise: maximum cardiovascular benefits are obtained if performed at moderate doses, while these benefits are lost with (very high) intensity and prolonged efforts."

Published on

It seems that research showing benefits of exercise is multiplying. This study only looked at men, and if you look at the "after age 40 group", their average age of starting endurance training was 48. From Science Daily:

Forty not too old or too late to start endurance training

A study of healthy senior men has found that "relatively intensive" endurance exercise confers benefits on the heart irrespective of the age at which they began training. The benefits were evident and comparable in those who had started training before the age of 30 or after the age of 40. As a result, said the investigators, 40 is not too old to start endurance training.

The study was performed in 40 healthy men (without cardiovascular risk factors) aged between 55 and 70 years who were divided for assessment according to the level of exercise they took and the ages at which they began. Thus, 10 of the men had never exercised for more than 2 hours a week throughout their lives, and 30 had exercised for at least 7 hours a week for over five years.

The regular exercise they took was either running or cycling. Those beginning before the age of 30 had been training for an average of 39 years (since the age of 22) and those starting at 40 for 18 years (since the age of 48).

First, resting heart rate was found to be similar between the two exercise groups (T30 56.8 bpm, T40 58.1 bpm), but significantly faster in the non-exercising men (69.7 bpm). Maximal oxygen uptake was also similar between the T30 (47.3 ml/min/kg) and T40 groups (44.6 ml/min/kg), but significantly lower in the non-exercising men (33.0 ml/min/kg).

The study also found no difference between T30 and T40 in cardiac echocardiography tests. "Thus," said Matelot, "despite biological changes with age, the heart still seems -- even at the age of 40 -- amenable to modification by endurance training. Starting at the age of 40 does not seem to impair the cardiac benefits.

Matelot pointed out that aging is associated with adverse structural and functional changes to the cardiovascular system. And, while physical activity is unable to prevent these changes, it is able to slow them down.

Published on

Once again research shows problems with physical inactivity: this time heart disease risk in women. From Science Daily:

From age 30 onwards, inactivity has greatest impact on women's lifetime heart disease risk

From the age of 30 onwards, physical inactivity exerts a greater impact on a woman's lifetime risk of developing heart disease than the other well-known risk factors, suggests research published online in the British Journal of Sports Medicine. This includes overweight. the findings show, prompting the researchers to suggest that greater effort needs to be made to promote exercise.

The researchers wanted to quantify the changing contribution made to a woman's likelihood of developing heart disease across her lifetime for each of the known top four risk factors in Australia: excess weight (high BMI); smoking; high blood pressure; and physical inactivity. Together, these four risk factors account for over half the global prevalence of heart disease, which remains the leading cause of death in high income countries.

They based their calculations on estimates of the prevalence of the four risk factors among 32,154 participants in the Australian Longitudinal Study on Women's Health, which has been tracking the long term health of women born in 1921-6, 1946-51, and 1973-8, since 1996.

Combining the prevalence and relative risk data, the researchers found that up to the age of 30, smoking was the most important contributor to heart disease, with a PAR of 59%. But from age 30 until the late 80s, low physical activity levels were responsible for higher levels of population risk than any of the other risk factors.

The researchers estimate that if every woman between the ages of 30 and 90 were able to reach the recommended weekly exercise quota -- 150 minutes of at least moderate intensity physical activity -- then the lives of more than 2000 middle aged and older women could be saved each year in Australia alone.

Published on

Years ago the advice was to really limit exercise during pregnancy, but times have changed. Now studies find exercise during pregnancy beneficial for both the mother and baby. From Discover:

Exercise During Pregnancy Benefits Mom—And Baby, Too

Women who exercise with baby on board have been known to have, among other things, lower risks of gestational diabetes and pregnancy-induced high blood pressure than those who don’t.

In 1985, the American Congress of Obstetricians and Gynecologists came out with their first set of guidelines for exercise during pregnancy—guidelines, now considered conservative, that included suggestions like keeping strenuous activities to 15 minutes or less. Since then, research has turned that idea on its head. Exercise is now thought to be—for most women with healthy pregnancies—a boon for the mother's health, and for the baby she carries as well.

It’s been known that those who exercise—including pregnant women—tend to have lower resting heart rates than those who don’t. Lower heart rates can be a sign of an efficient heart; high heart rates have been linked to greater risk of cardiovascular disease. May, now at East Carolina University in North Carolina, has long been interested whether benefits like this extended to baby.  In a 2010 study, she and her colleagues collected a group of 26 pregnant women who reported that they’d been exercising three times a week for more than 30 minutes per session.  When researchers brought the moms into the lab at 36 weeks, they found that the babies in their bellies, too, had lower heart rates than those carried by the moms they studied who weren’t regular exercisers.

The results indicate that exercise during pregnancy, far from harming the fetus, can be incredibly beneficial for both mom and baby. And timing matters: exercise during pregnancy, as opposed to pre-pregnancy fitness, seems to be doing something extra-special, May says. In this most recent study, about half of the group hadn’t exercised previously, and still saw similar effects on their babies’ hearts. 

Such benefits to the heart may last into a child’s early life. Earlier this year, May and colleagues found that month-old infants still had higher heart rate variability if they had exercised along with their moms in utero. Another set of results from May’s group, not yet published, suggests that kids up to six years old still carry some of these early workouts with them: youngsters whose moms exercised while pregnant have higher “ejection fractions,” which indicates their hearts are pumping blood more efficiently.

Studies report that only about 10 to 30 percent of pregnant women are following recommended exercise guidelines—for healthy women, at least 30 minutes of moderate exercise most, if not all, days, according to the American Congress of Obstetricians and Gynecologists.. (Of course, some women can’t safely exercise during part or all of their pregnancy, and active women should watch out for warning signs while exercising, such as bleeding or contractions.)

Published on

Please note that in the following study 200 grams is a measure of weight, and a little over a cup of many fruits and vegetables. Some examples: blueberries 1 cup=190 grams, green peas 1 cup=145 grams, but young salad greens 1 cup=20 grams. From Medical Daily:

Consuming Up To 200 Grams Of Fruits And Vegetables Will Decrease Your Stroke Risk

It’s not surprising that fruits and vegetables are the key to various health benefits, and now researchers are emphasizing their importance for reducing the risk of stroke.

In the study, researchers found that the stroke risk declined by 32 percent for the participants who ate 200 grams of fruit per day — and decreased by 11 percent for every 200 grams of daily vegetables. “Improving diet and lifestyle is critical for heart and stroke risk reduction in the general population,” Dr. Yan Qu, senior study author and director of the intensive care unit at Qingdao Municipal Hospital in China, said in a news release. “In particular, a diet rich in fruits and vegetables is highly recommended because it meets micronutrient and macronutrient and fiber requirements without adding substantially to overall energy requirements.”

Authors of the study reviewed 20 studies over the course of 19 years that involved over 760,000 people throughout the U.S., Asia, and Europe. The beneficial effects of fruits and vegetables were apparent across the board in both men and women. 

 

Published on

Finally, a paper on some (but only some) of the chemicals linked to breast cancer and how to measure them in a woman's body. From Medical Xpress:

Study lists dangerous chemicals linked to breast cancer

Certain chemicals that are common in everyday life have been shown to cause breast cancer in lab rats and are likely to do the same in women, US researchers said Monday. The paper in the peer-reviewed journal Environmental Health Perspectives lists 17 chemicals to avoid and offers women advice on how to minimize their exposure. They include chemicals in gasoline, diesel and other vehicle exhaust, flame retardants, stain-resistant textiles, paint removers, and disinfection byproducts in drinking water.

Some of the biggest sources of mammary carcinogens in the environment are benzene and butadiene, which can come from vehicle exhaust, lawn equipment, tobacco smoke and charred food.

Other concerns are cleaning solvents like methylene chloride, pharmaceuticals used in hormone replacement therapy, some flame retardants, chemicals in stain-resistant textiles and nonstick coatings, and styrene which comes from tobacco smoke and is also used to make Styrofoam, the study said. Carcinogens can also be found in drinking water, researchers said.

"Unfortunately, the link between toxic chemicals and breast cancer has largely been ignored. Reducing chemical exposures could save many, many women's lives." Brody described the paper as the first to comprehensively list potential breast carcinogens and detail ways for experts to measure them in women's blood and urine.

The study also recommends seven ways for women to avoid these chemicals:

1) Limit exposure to exhaust from vehicles or generators, don't idle your car, and use electric lawn mowers, leaf blowers and weed whackers instead of gas-powered ones. 2) Use a ventilation fan while cooking and limit how much burned or charred food you eat. 3) Do not buy furniture with polyurethane foam, or ask for furniture that has not been treated with flame retardants. 4) Avoid stain-resistant rugs, furniture and fabrics. 5) If you use a dry-cleaner, find one who does not use PERC (perchloroethylene) or other solvents. Ask for "wet cleaning." 6) Use a solid carbon block drinking water filter. 7) Keep chemicals out of the house by taking off your shoes at the door, using a vacuum with a HEPA (high-efficiency particulate air) filter, and cleaning with wet rags and mops.

Published on

Researchers found that many common chemicals, including Triclosan, interfere with normal sperm function. Perhaps this is contributing to fertility problems.From Science Daily:

Endocrine disruptors impair human sperm function, research finds

A plethora of endocrine-disrupting chemicals interfere with human sperm function in a way that may have a negative impact on fertilization. These are the findings of a German -- Danish team of researchers from the Center of Advanced European Studies and Research in Bonn, Germany, and the University Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark. The work, which is published in EMBO reports,suggests that endocrine disruptors may contribute to widespread fertility problems in the Western world in a way that hitherto has not been recognized.

Endocrine disruptors are present in food, textiles, drugs, household, and personal-care products such as plastic bottles, toys, and cosmetics. Proving the deleterious effects of endocrine disruptors on human beings has been difficult due to a lack of suitable experimental systems.

"For the first time, we have shown a direct link between exposure to endocrine disrupting chemicals from industrial products and adverse effects on human sperm function,'' said Niels E. Skakkebaek, professor and leader of the Danish team.

Hundreds to thousands of chemicals can be rapidly tested for their potential to interfere with human sperm function using the bioassay developed by the researchers. In this initial study, about one hundred chemicals were tested. Around one third, including ultraviolet (UV) filters like 4-methylbenzylidene camphor (4-MBC) used in some sunscreens, the anti-bacterial agent Triclosan used in toothpaste, and di-n-butylphthalate (DnBP), showed adverse actions.

Altogether, the study indicates that endocrine disruptors might disturb the precisely coordinated sequence of events underlying fertilization in several ways: the chemicals might evoke changes in swimming behaviour at the wrong time and wrong place, hinder navigation of sperm towards the egg, and hamper penetration into the protective egg coat.

Different article about the same research, and here they also discuss the very important finding that mixtures of common chemicals have an even stronger adverse "cocktail effect" on sperm. From The Independent:

Chemicals in soap can cause male infertility, claim scientists

They also found that the concentrations needed to trigger these adverse reactions were similar to the very low levels commonly found within the human body. In addition, they showed for the first time that there was a “cocktail effect”, when a number of chemicals worked together to amplify their individual effects.

Published on

Now we need ways to nurture our skin bacteria. From Science Daily:

Bacteria on the skin: Our invisible companions influence how quickly wounds heal

A new study suggests microbes living on our skin influence how quickly wounds heal. The findings could lead to new treatments for chronic wounds, which affect 1 in 20 elderly people.

We spend our lives covered head-to-toe in a thin veneer of bacteria. But despite a growing appreciation for the valuable roles our resident microbes play in the digestive tract, little is known about the bacteria that reside in and on our skin. A new study suggests the interplay between our cells and these skin-dwelling microbes could influence how wounds heal.

Chronic wounds -- cuts or lesions that just never seem to heal -- are a significant health problem, particularly among elderly people. An estimated 1 in 20 elderly people live with a chronic wound, which often results from diabetes, poor blood circulation or being confined to bed or a wheelchair."These wounds can literally persist for years, and we simply have no good treatments to help a chronic wound heal," said Hardman, who added that doctors currently have no reliable way to tell whether a wound will heal or persist. 

In their recent study, Hardman and his colleagues compared the skin bacteria from people with chronic wounds that did or did not heal. The results showed markedly different bacterial communities, suggesting there may be a bacterial "signature" of a wound that refuses to heal. "Our data clearly support the idea that one could swab a wound, profile the bacteria that are there and then be able to tell whether the wound is likely to heal quickly or persist, which could impact treatment decisions," said Hardman.

The team also conducted a series of studies in mice to shed light on the reasons why some wounds heal while others do not. They found that mice lacking a single gene had a different array of skin microbiota -- including more harmful bacteria -- and healed much more slowly than mice with a normal copy of the gene. The gene, which has been linked to Crohn's disease, is known to help cells recognize and respond to bacteria. Hardman said the findings suggest that genetic factors influence the makeup of bacteria on a person's skin, which in turn influences how they heal.