Nerves Light Up to Warn Surgeons Away

Nerve endings: In mice, it is hard to see nerves that descend into a tumor under normal light (left, in blue). But when the mice are injected with a nerve-specific fluorescent probe, the buried branches are easier to see (middle). Combined with a tumor probe, the approach can highlight both the tumor to be removed (right, in green) and the nerves to be spared.
Credit: Michael A. Whitney et al

Tagging nerves with fluorescent markers could help surgeons avoid harming them.

MIT Technology Review, by Courtney Humphries  —  Surgeons take pains to avoid injuring nerves in and around surgical sites—a stray cut could lead to muscle weakness, pain, numbness, or even paralysis. In delicate operations like prostate removal, for instance, accidentally damaging nerves can lead to incontinence or erectile dysfunction. Scientists at University of California San Diego have announced a new method for lighting up nerves in the body with fluorescent peptides, which could act as markers to keep surgeons away.

Quyen Nguyen, a surgeon at UCSD who led the research, says that during their training, surgeons learn where nerves are located and use that knowledge to avoid them. Most of the time, knowledge and experience are enough, but if anything is out of place or damaged for some reason, “finding the nerves can be challenging,” Nguyen says. Fluorescence offers a way to let surgeons see them “even before they encounter them with their tools,” she says.

Nguyen, working with chemist Roger Tsien, has previously created fluorescent markers that can illuminate the margins of tumors during surgery. To identify a specific tag for nerves, her team used a technique called phage display. A phage is a virus that infects bacteria, and it displays a small protein on its surface called a coat. Scientists can easily change the sequence of amino acids of this protein, creating millions of phages that display different coats. Using this technique, Nguyen’s team looked for sequences of amino acids that preferentially stuck to nerve cells, and used that information to design a peptide that can serve as a nerve-specific tag. By adding a fluorescent probe to the peptide, they created a beacon that illuminates nerves under a particular wavelength of light.

The researchers injected their peptide into the bloodstream of mice, and found that all peripheral nerves (those outside the brain and spinal cord) were labeled within two hours. The effect lasted for several hours, and was completely gone after a day. The label worked even if nerves were damaged. The researchers also tested the peptide in human tissue samples and confirmed that it would also bind to human nerves.

These probes could be used in concert with probes for cancer, helping a surgeon to remove a tumor while avoiding the nerves around it. The technology has been licensed by Avelas Biosciences, a small biotech startup cofounded by Tsien; further animal testing will be needed before it’s ready for clinical studies.

Hisataka Kobayashi, chief scientist in the Molecular Imaging Program at the National Cancer Institute, says that “there’s no question this is a great technology” that has the potential to benefit surgeons. But he says the researchers will need to identify the exact molecular target of the probes and verify that they are completely nontoxic.

American InfraStructure: When the Train Seats Are Taken by Bacteria

Jason Martinez removed a dirty seat cushion from a BART train before replacing it with a clean one at the South Hayward train yard.  Photo Credit: Thor Swift for The Bay Citizen

The Bay Citizen

American InfraStructure: When the Train Seats Are Taken by Bacteria

By ZUSHA ELINSON

Published: March 5, 2011

Carrie Nee prefers to stand during her half-hour commute on BART from San Leandro to downtown San Francisco. Although the trains’ blue fabric seats are plush and comfortable, Ms. Nee refuses to sit on them.

Thor Swift for The Bay Citizen

Jason Martinez removed a dirty seat cushion from a BART train before replacing it with a clean one at the South Hayward train yard.

A nonprofit, nonpartisan news organization providing local coverage of the San Francisco Bay Area for The New York Times. To join the conversation about this article, go to baycitizen.org.

“I would love to sit down, but it just grosses me out. They’re disgusting,” said Ms. Nee, a 26-year-old records clerk.

Riders on the Bay Area Rapid Transit system have long complained about germs in the hard-to-clean cloth seats. As Bob Franklin, the BART board president, acknowledged, “People don’t know what’s in there.”

Now they do.

The Bay Citizen commissioned Darleen Franklin, a supervisor at San Francisco State University’s biology lab, to analyze the bacterial content of a random BART seat. The results may make you want to stand during your trip.

Fecal and skin-borne bacteria resistant to antibiotics were found in a seat on a train headed from Daly City to Dublin/Pleasanton. Further testing on the skin-borne bacteria showed characteristics of methicillin-resistant staphylococcus aureus, or MRSA, the drug-resistant bacterium that causes potentially lethal infections, although Ms. Franklin cautioned that the MRSA findings were preliminary.

High concentrations of at least nine bacteria strains and several types of mold were found on the seat. Even after Ms. Franklin cleaned the cushion with an alcohol wipe, potentially harmful bacteria were found growing in the fabric.

Dr. John Swartzberg, a clinical professor at the School of Public Health at the University of California, Berkeley, played down the threat of infection from harmful bacteria on a BART seat. “I suspect it’s not a very big problem,” Dr. Swartzberg said. “That said, if there’s another way to do it, where you can clean it better, then you should do it.”

He said the cloth seats most likely allowed bacteria to flourish because they were more difficult to clean and disinfect.

James Allison, a BART spokesman, wrote in an e-mail that the findings were “not surprising,” considering that 330,000 commuters rode the trains daily. Last year, the BART police received 1,051 complaints of smoking, eating and drinking; 245 complaints of urinating or defecating; and 56 reports of spitting.

Mr. Allison encouraged riders to wash their hands and use hand sanitizers available at BART stations.

Hygiene has emerged as a key issue as BART officials determine what kind of seats to install for a new fleet of cars in 2017. In January, system employees were invited to test a variety of seat models at a Hayward warehouse. One employee, Melissa Jordan, filed a report on BART’s Web site about the trade-offs in selecting the new seats.

“Can I live with some type of seat that’s less cushiony — maybe padded vinyl instead of fabric — if it’s easier to keep clean?” Ms. Jordan wrote.

Ms. Franklin’s analysis also revealed that Muni, which uses acrylic plastic seats, appears to be more sanitary.

She tested a seat on the No. 28 bus, a route frequented by college students traveling from San Francisco State to Daly City. Two benign bacteria colonies were found. Unlike the BART seat analysis, Ms. Franklin’s test of the Muni seat after cleaning it with an alcohol wipe detected no bacteria.

Ms. Franklin tested the BART seat at the back of a Dublin/Pleasanton-bound train in the midafternoon. A swab taken from the seat cushion and headrest produced a veritable forest of mold and colorful bacteria.

In two separate tests, Ms. Franklin identified characteristics of the MRSA bacteria growing in the seat. The first test confirmed the presence of staphylococcus aureus, the skin-borne bacteria. A second confirmed that the bacteria, like MRSA, was resistant to the antibiotics methicillin and penicillin. But a third test intended to isolate the MRSA bacteria was negative.

MRSA is known as the “superbug” because it is resistant to antibiotics. It infects people through open wounds, attacking the immune system; 19,000 deaths each year are related to MRSA infections, according to the Centers for Disease Control and Prevention.

“There’s a probability that it is MRSA, but more tests would need to be done,” Ms. Franklin said. “Somebody probably was wearing shorts and had an infection, and there you go. It is concerning.”

Ms. Franklin identified two other bacteria strains that she said resulted from fecal contamination of the BART seat. Those strains were also resistant to antibiotics. The other bacteria did not appear to be harmful and are found throughout the environment, Ms. Franklin said.

The soft seat is a BART trademark, going back to Sept. 11, 1972, the day the first train rolled down the track. The seat covers are made of 90 percent wool and 10 percent nylon and are filled with foam padding, which was made fire-resistant after a fire in the Transbay Tube in 1979.

A BART brochure proclaimed that the new trains were designed to “lure the commuter out of the comfort of his automobile.” The trains were “almost as wide as a Boeing 707, and every bit as comfortable,” according to the brochure, which was printed in the shape of a BART car.

“BART was an all-new system, and they wanted everything to be different,” said Mike Healey, who was a BART spokesman at the time. “They wanted cushioned seats and rugs on the floors. Comfort was certainly a key selling point for the system.”

The marketing campaign worked. Ridership has grown. And the once-quiet suburban commuter train is now a heavily trafficked line.

“Things have changed,” said Mr. Franklin, the BART board president. “Now you’re no longer guaranteed a parking space. You’re no longer guaranteed a seat. There are 350,000 people traveling every day, as opposed to 50,000.”

BART cleaners go through trains every night and tackle the dirtiest seat cushions. Hard surfaces are wiped down with an industrial disinfectant.

Between 300 and 500 seat covers are removed each week and sent to a third-party vendor to be dry-cleaned and disinfected, Mr. Allison said. But that is a fraction of the 40,000 seats on BART’s 669 cars.

Dry-cleaning costs BART $595,000 a year. When necessary, BART replaces the cloth seats for an entire car — generally about 60 seats — at a cost of about $12,500. The system intends to continue rotating in new cloth seats as it continues to try out seats for the new cars.

Mr. Allison said that a major concern in designing the new cars was cleaner, more comfortable seating. BART plans to let the public test different types of seats in demonstration cars and then comment on their suitability.

Mr. Allison said that the choices for new seat models included hard plastic and padded vinyl.

Ms. Nee, the BART rider, said she would prefer hard plastic, especially after hearing the results of the bacteria analysis.

“I would seriously sacrifice my comfort for a more sanitary surrounding,” she said. “Granted, you’re going to be comfortable with the seats they have now, but I think your health is much more important than having your butt hurt for half an hour.”

zelinson@baycitizen.org

We posted information about this new study, last week, as soon as the research news came out.  However, this study, should be such a life altering motivator, we are posting the comments of a fitness MD, specializing in sports medicine, Gabe Mirkin MD. – Joyce Hays

How Exercise Keeps You Young (and Prolongs Your Life)

By Gabe Mirkin MD, March 7, 2011  —  Dr. Mark Tarnopolsky, of McMaster University in Hamilton, Ontario, has shown that exercise prevents aging in mice programmed to grow old rapidly (The Proceedings of the National Academy of Sciences, September 22, 2010). The exercising mice did not have the expected shrinkage with aging of their brains, hearts, muscles, skin, hair, ovaries, testicles, spleen, kidneys, and liver. Many other studies show that exercise in later life slows signs of aging such as loss and graying of hair, weaker and smaller muscles, loss of brain function and size, thinning of skin, damage to blood vessels associated with heart attacks and strokes, loss of apoptosis associated with increased cancer risk, and loss of sexuality associated with shrinking of testicles and ovaries.

The explanation for these incredible findings appears to be in the mitochondria that convert food to energy for your body. At all ages, the exercising mice appeared younger and healthier than the non-exercising mice. Mitochondria have a different DNA than other cells in mammals. That means that in the process of evolution, bacteria invaded cells and provided the ability to turn sugar to energy more efficiently than any other process in the body. Aging in humans is associated with loss of function and number of mitochondria which causes decline in tissue functions that causes cancers, arteriosclerosis, diabetes, and Parkinson’s and Alzheimer’s disease. With aging, genetic mutations cause mitochondria to malfunction and die and you to look older.

As you age, you lose your ability to make AMP-activated protein kinase, also known as AMPK (Cell Metabolism, February 2007). This enzyme functions to increase mitochondria in muscles. Anything that reduces the number or efficiency of mitochondria interferes with your body’s ability to burn fat and sugar for energy. As a result, blood sugar, fat and cholesterol levels rise. Most cells in your body contain many mitochondria, small furnaces that burn food for energy. With aging, the number and the efficiency of mitochondria both decrease. This interferes with your body’s ability to turn food into energy. The extra calories that are not burned accumulate in your body as fat in your muscles, liver and fat cells. This causes you to gain weight. Extra fat in cells block their ability to take in sugar from the blood stream, so blood sugar levels rise and you are at increased risk for developing diabetes. Extra fat in the liver prevent the liver from removing extra insulin, so insulin levels rise to constrict arteries and cause heart attacks. Insulin also makes you hungry all the time to increase your chances of gaining weight.

AMPK is increased by exercise and by drugs used to treat diabetes, such as metformin or Actos. The best way to increase the number and size of mitochondria in your cells is to exercise. If you do not have a regular exercise program, you are shortening your life.
How exercise strengthens mitochondria and prevents aging

The benefits reported in mice appear to apply to humans. For the last two years, Diana and I (ages 69 and 75) have been part of group of tandem bicycle riders, ages 40s to 70s, who race flat out for 25 to 30 miles three times a week and ride more than 100 additional miles in the rest of the week. All look younger, are thinner and more muscular, and are far more active than their same-age contemporaries in The Villages, Florida where we live.

Consider a Walkstation Instead of a Workstation

Dr. James Levine of the Mayo Clinic came up with the idea of a “Treadmill Desk”. The idea is to slowly walk on a treadmill while working at a desk built around the treadmill…a Treadmill Desk.

Dr Levine’s research revealed that on the average his subjects burned 100 extra calories every hour while walking slowly — at 1 mile per hour — than while sitting in a chair.

Dr. Levine believes that if individuals were to replace 8 hours a day of sitting at their “normal” desk with a Treadmill Desk, and if other components of energy balance were constant, a weight loss of 57 pounds a year could occur.

This website is designed to provide everything you need to know if you want to become a member of the Treadmill Desk revolution. Don’t miss the movies and slide shows over on your left.
Above: The Smooth Fitness 7.6HR Pro

Consider a Recumbant Stationary Bike For Home and/or Office