Surgeons Report High-Tech Spectacles Ease Strain


Patients going under the knife aren't the only ones who end up with their share of aches and pains after an operation. Many physicians grapple with substantial neck and back strain by the end of a grueling day in the surgical suite.

Now University of Florida researchers say a pair of lightweight, high-tech glasses could be the prescription for relief. They put the eyewear to the test and found it helped prevent much of the discomfort surgeons experience after performing minimally invasive procedures. These operations usually require surgeons to peer at a small video monitor placed at an awkward angle up to 10 feet away.

The high-resolution glasses project a 52-inch stereoscopic image about six feet into space, enabling doctors to view the operative field no matter where they turn their heads.
Dr. Scott Schell demonstrates eyeglasses he developed that project the view from microsurgical equipment directly in front of the eyes so a doctor does not have to twist in an unnatural and tiring position to watch a monitor.

“Minimally invasive or laparoscopic surgery has really been a dramatic and revolutionary improvement in the performance of certain procedures, not only for the safety and comfort of patients but also for cost and outcome,” said Dr. Scott Schell, an assistant professor of surgery and of molecular genetics and microbiology at UF’s College of Medicine. “But, in contrast to standard operating procedure where surgeons stand and look down at their hands while operating, during minimally invasive surgery the hands may be pointed in a completely different orientation than where the eyes are looking because the surgeons are not looking at a wound, they’re looking at a screen. So in lengthy procedures, that practice increases the possibility they could develop neck and back strain because they’re not in a comfortable position.”

During minimally invasive procedures, surgeons make tiny incisions — some as small as an eighth of an inch — and thread a fiber-optic camera through a catheter to see inside the body. The operation is performed using surgical instruments inserted through the incisions. Depending on the operation, minimally invasive procedures can last anywhere from 30 minutes to eight hours.

Surgeons wearing the video-projection glasses can look down at their hands while operating — a more natural and comfortable orientation, Schell said. The eyewear resembles a large pair of sunglasses and weighs about 3.5 ounces.

“The glasses provide a picture of what you’d see inside the abdomen if you opened up the abdomen,” Schell said.

Scott Schell,

by Melanie Fridl Ross


Gene Therapy Could Protect Heart During Attacks

A team of University of Florida researchers has used gene therapy to develop a tiny biological machine that could one day be injected into heart attack-prone patients to recognize and stop new heart attacks.

The UF team used a harmless virus to deliver a combination of genes to animal heart tissue that protected the tissue from heart attacks, according to an article in Hypertension, a journal of the American Heart Association. The virus sensed when the heart tissue began to experience hypoxia, or oxygen deprivation, and switched on the protective genes, which prevented the damage and scarring, called ischemia, that usually results.

It may take years, but UF researchers say the technique of using such “vigilant vectors” to transmit gene switches could be translated into treatments for a host of other disorders as well, such as diabetes and stroke.

“The concept is that we give an IV injection, and although the vector goes everywhere in the body, it only works in the heart or other targeted organ or tissue,” said Ian Phillips, the study’s principal investigator and a professor and chairman emeritus of the UF College of Medicine’s Department of Physiology. “It just waits there until the right moment arrives to help the person.”

The UF team used the adeno-associated virus, a commonly used gene carrier, to insert the cardio-protective gene switch. The apparently harmless virus, known as AAV, has unusual properties that make it ideal for transporting corrective genes into human cells, including that it carries no DNA of its own, Phillips said.

The UF team spent two years developing the heart-attack-preventing gene “switch” using a combination of genes from human and yeast cells, Phillips said.

Active only in heart tissue, the switch “turns on” the protective genes during the four- to six-hour window when hypoxia is known to lead to ischemia. This defends the heart cells in the low-oxygen condition and subsequently prevents damage to the heart tissue, Phillips said. When the hypoxia goes away, the switch turns off again.

The research has so far proved successful in animal tissue cultures and on a limited basis in experiments with live rats, but Phillips said developing experiments and treatment for people is still many years away.

Ian Phillips,

by Aaron Hoover


Plastic Film Being Tested To Regulate Plant Growth

Sandra Wilson, assistant professor of environmental horticulture, examines a wine sage plant grown in a greenhouse covered in photo-selective polyethylene film. The new film, which filters out far-red light waves, is used to keep plants compact to ease shipping problems.


To help commercial nurseries keep plants uniform in size, University of Florida researchers are testing colored plastic films that filter out growth- promoting light waves.

Sandra Wilson, an assistant professor of environmental horticulture with UF’s Institute of Food and Agricultural Sciences, said the photo-selective plastic film in her current experiment filters out far-red light, which is responsible for stem elongation in plants.

“When grown in a greenhouse covered with photo-selective film, plants respond to subtle changes in the amount of far-red light they receive,” Wilson said. “The goal is to inhibit stem elongation without sacrificing plant quality.”

The horticulture industry prefers uniform plant size because it speeds plant establishment in the field and makes it easier to pack and ship mature plants. Traditionally, chemicals have been used to control plant height but, because of increasing environmental concerns, researchers are seeking other methods to control plant height.

Wilson has been testing the new film on subtropical annuals and perennials at UF’s Indian River Research and Education Center in Fort Pierce, where she has obtained favorable results.

“Most plants grown under the far-red light-absorbing film are about 25 percent shorter than plants grown under clear film, which is used as a control standard to compare effects of the colored film,” Wilson said. “The results are comparable to plants treated with chemical growth regulators.”

Japan-based Mitsui Chemicals contracted with UF and several other institutions to test the green film in various regions of the United States. Ohio State University and Clemson are testing plants from their regions, and UF is testing Southern plants.

“Because of Florida’s warm climate, we can grow subtropical plants,” Wilson said. “This was a good trial because many of the species we worked with in Fort Pierce were traditionally ‘leggy,’ meaning they grow fast and are extremely elongated. The good results with these plants bode well for other species.”

Wilson said UF is also testing the polyethylene film to determine if it degrades faster in hot regions.

“One of the problems we’ve encountered has been a short film life,” Wilson said. “The dyes start to degrade after one year, so research is being conducted to increase the stability of the dyes.”

In addition to ornamental plants, the colored films have been used on food plants such as bell peppers, tomatoes and watermelons.

Sandra Wilson,

by Paul Kimpel


Computer Networks Possible Via Power Outlets

Thanks in part to University of Florida research, people soon will plug into home or office outlets for more than just electricity.

Adapters and other products will make it possible to use existing electrical wiring to access the Internet, and to network computers and computing devices such as printers. The “powerline networking” technology, which backers say provides more consistent service than competing wireless systems, could reduce the need for expensive cable installations in houses or buildings built before the Internet boom.

“Power lines for many years have been ignored as communication channel because they were too noisy and unpredictable,” said Haniph Latchman, a UF professor of electrical and computer engineering. “But recent advances at UF and elsewhere have changed that scenario, and those advances are now reaching the consumer.”

Latchman is among four UF engineering researchers who have worked with engineers at Ocala-based Intellon Corp. over the past two years in the research, development, simulation and testing of the “no new wires” technology. Intellon builds the computer chips at the heart of wall outlet adapters, cards and other products that several companies plan to market nationwide.

Latchman said the need for simple and effective local area networks, or “LANs,” is skyrocketing as people add more computers to homes and so-called “smart” appliances steadily become a reality. For example, IBM and Carrier recently announced plans to sell an air conditioner adjustable via e-mail, allowing residents to pre-set the temperature before they step in the door, he said. Down the road, “intelligent” refrigerators are expected to automatically note their contents’ shortages and even order groceries over the Internet.

The main barrier to such developments is that millions of older homes are not equipped with the computer cable that supports high-speed networks, and many newer homes do not have the network cable in every room. Laptops and handhelds, meanwhile, are most useful when they can access the network virtually anywhere, such as poolside or on the patio.

Electricity lines were not designed for conveying high-frequency signals needed to send and receive data, so they contain interference and noise. But UF and Intellon researchers have developed ways to maintain clear communication, Latchman said.

The technology is ideal for smart homes because it makes the network so accessible. “If you plug in your fridge or A/C, they’re automatically part of the network,” Latchman said.

Haniph Latchman,

by Aaron Hoover


Cell Suicide A Possible Culprit In Heart Disease

Scientists have known for years that the heart is one of the first organs to show the ravages of time. Now, two University of Florida researchers say they know why: cell suicide.

In a study published in the February issue of the American Journal of Physiology, researchers at UF’s College of Health and Human Performance attempted to determine why heart cells in older rodents die at much higher rates than those of their younger counterparts.

The process is known as apoptosis. It’s what happens when a cell orders itself to stop functioning, shrink and ultimately dissolve. Although apoptosis plays a critical role in removing unwanted and potentially dangerous cells, such as tumor cells, excessive apoptosis may contribute to the decline in cardiovascular function with age, said Christiaan Leeuwenburgh, director of UF’s Biochemistry of Aging Laboratory and one of the study authors.

In their study, Leeuwenburgh and Sharon Phaneuf, a third-year doctoral student, obtained hearts from 6-, 16- and 24-month-old rats and isolated the heart cells’ mitochondria, which helps supply the cell with energy. In human terms, the rats would have been roughly 20, 55 and 75 years old.

The scientists studied cytochrome c, a mitochondrial electron transporter that becomes a signal for cell death if it is released from the mitochondria. Phaneuf found the hearts of older animals released greater amounts of that cell-death signal than did the hearts of younger animals and may be partly responsible for the increase in cell death.

Quantifying apoptosis is difficult, but estimates show a healthy elderly male without heart disease or high blood pressure loses 30 percent of his heart cells, said Leeuwenburgh, an assistant professor of exercise and sport sciences.

Leeuwenburgh and Phaneuf attribute the disorder to oxidative stress, a condition in which cells have too many free radicals — destructive, highly reactive molecules — and not enough antioxidants, which counteract the damaging effects of aging.

The National Institute on Aging and the Society for Geriatric Cardiology co-funded the study.

Christiaan Leeuwenburgh,

by Kate Palmer


Plan Puts Idle PCs To Work In “Computing Marketplace”

Here’s a nice thought in these economic doldrums: The computer sitting idle at home while you’re at work could instead earn you some spare cash.

A University of Florida engineering professor is leading an effort to create a way to allow PC owners to sell their machines’ computing power online.

Michael Frank, an assistant professor of computer and information science and engineering, says millions of computers in people’s homes and offices spend hours doing little more than running screen savers. Meanwhile, scientists, corporations and public officials often need more computing power than they can afford.

A free system that allows PC owners to sell their personal machines’ processing power to these and other customers as needed online would benefit everyone, he says.

“There are markets for all kinds of resources, everything from electricity to grain,” Frank said. “The idea is to do the same thing with computers.”

Frank said more than 50 million Americans are connected to the Internet, yet their computers sit idle most of the time. Meanwhile, scientists studying global weather patterns or genetics often need access to massive amounts of computer processing and memory. Ditto computer graphics firms and public officials and news organizations, who need added computing power.

These and other groups may not have the money to invest in expensive supercomputers, especially when they may need the computing power only occasionally, Frank said. It would be far better if they could simply “buy” it online from the millions of computer owners not using their full processing power.

As he described it, “Imagine that the collective computational power of millions of computers all over the world becomes a vast, liquid commodity, flowing like an ocean between continents, fluctuating up and down in price according to global needs and supply and demand.”

Frank and a group of about two dozen faculty and graduate students are trying to engineer this new approach.

They call it the Open Computation Exchange & Auctioning Network, or OCEAN.

The network’s foundation will be a software program freely available on the Web.

“It has to be so easy to use and so simple that it grows and develops its own market in a kind of grass-roots way,” Frank said.

The technical hurdles are not minor. Ensuring people’s personal computers remain secure, even as their central processing units and hard drives are accessed via the Internet, is one issue. Another is creating a simple and safe accounting and billing system.

Assuming there is a healthy demand for the service, Frank estimated owners of up-to-date PCs might be able to earn $50 per month to “rent” their processing power. Some applications may require a permanent on-line connection, others only periodic uploads and downloads.

Michael Frank,

by Aaron Hoover


Building To House Cancer,  Biotech & Genetics Labs

A congressional appropriation of $2.25 million, approved by President George W. Bush in November, will facilitate construction of an $80 million facility for genetics, cancer and biotechnology research at the University of Florida.
The building will be immediately west of the UF Health Science Center at the intersection of Archer Road and North-South Drive and will have its own utility plant. By locating it next door to the Jerry and Judith Davis Cancer Center, an outpatient facility of the UF Shands Cancer Center, planners hope it will be easy for scientists

Terry Flotte, left, director of the UF Genetics Institute, Sheldon Schuster, director of the Interdisciplinary Center for Biotechnology Research, and Stratford May, director of the UF Cancer Center, at the site of a planned $80 million Cancer and Genetics Building. who are exploring cancer at the cellular, molecular and genetics levels to collaborate with health professionals caring for patients.

U.S. Rep. Karen Thurman, who advocated on behalf of the university for the latest federal funds, said, “The building will provide a valuable research environment for scientists to discover the genetic abnormalities that cause cancers and other diseases, and to develop effective ways to treat the patients.

“This state-of-the-art facility will help to encourage collaboration among scientists from various backgrounds, speed the process of discovery and, ultimately, save lives,” Thurman said.

A $6.5 million biotechnology research pavilion — a new home for the Interdisciplinary Center for Biotechnology Research (ICBR) — will be the first part of the complex to be built. The pavilion will feature laboratories designed and equipped to help scientists explore the genetic makeup of humans, animals and plants.

Sheldon Schuster, ICBR director, views the future facility as a crossroad for scientists in the field of genetics and other life sciences at the molecular level. He said scientists working in the pavilion will be able to sequence and analyze DNA and individual genes, analyze cells via flow cytometry, develop genetic markers for use in conservation biology and identify protein markers that signal environmental contamination or stress.

The genetics section will be occupied by close to 40 researchers, along with their support teams from the UF Health Science Center, UF’s Institute of Food and Agricultural Sciences and the Florida Museum of Natural History. The building will house the C.A. Pound Laboratory and the Maples Center for Forensic Medicine.

Dr. Terence Flotte, director of the UF Genetics Institute and the Powell Gene Therapy Center, said some of the key genetics research projects will include the development of human gene therapy, the Floral Genome Project to track the relatedness and biodiversity of plant species throughout evolutionary history and the Maize (corn) genome project to identify key genes involved in disease resistance and the nutritional quality of food crops.

Dr. Stratford May, director of the UF Shands Cancer Center, says close to 40 UF scientists and 300 support personnel will work in the cancer research laboratories.

UF Expert Helps Promote Tropical Fish Standards

Cyanide poisoning may be the stuff of murder mysteries, but it seems an unlikely way for tropical fish or coral reefs to die.

That’s what can happen, though, when divers in Southeast Asia use cyanide to capture valuable fish for sale to the aquarium trade, says a University of Florida expert who’s helping to evaluate standards for proper


capture, handling and sale of saltwater tropical fish and invertebrates such as coral, sea anemones and shellfish.   Sherry Larkin examines a saltwater tropical fish at a pet store in Gainesville. Larkin, a food and resource economist, is helping to evaluate standards for proper capture, handling and sale of saltwater species for the aquarium trade.

The divers use plastic squirt bottles filled with a diluted cyanide solution to stun fish long enough to net them, said Sherry Larkin, assistant professor with UF’s Institute of Food and Agricultural Sciences.

“The practice is common in Indonesia and the Philippines, which supply 85 percent of the world’s saltwater aquarium fish,” Larkin said.

The cyanide may later kill the target fish and harm nontarget species, live coral and even the divers themselves, she said. In some areas, entire reef ecosystems are in danger of being destroyed.

“People take shortcuts because it’s profitable,” she said. “We need to remove the profit motive. That’s what industrywide quality control standards could do.”

Larkin, a food and resource economist, is part of the first attempt to develop such standards, led by the Marine Aquarium Council, an international, nonprofit organization based in Honolulu. In November, the council, also known as MAC, launched a certification program to establish and enforce voluntary guidelines for every link in the industry chain that brings marine aquarium organisms from their native waters to retail consumers.

“If a fish is MAC-certified, everybody knows what they’re getting,” Larkin said. “They know destructive collecting practices weren’t used and that the fish was handled with appropriate regard for its health.”

With 1 million saltwater aquarium hobbyists, the United States accounts for more than half the worldwide demand for marine aquarium organisms, said Paul Holthus, executive director of MAC. While captive breeding efforts are slowly increasing, about 98 percent of marine ornamental fish and invertebrates currently sold are captured in the wild.

Larkin is conducting research to predict possible demand for MAC-certified organisms from saltwater aquarium hobbyists.

“Educating consumers will be critical to our success,” Holthus said. “They need to ask retailers for MAC-certified organisms. We’re planning awareness campaigns for major markets like New York and Los Angeles.”

Sherry Larkin,

by Tom Nordlie

Gene Therapy Could Delay, Control Parkinson’s

A team of researchers has demonstrated that the injection of two corrective genes into a specific brain region generated significant restoration of normal limb movement in rats with a chemically induced form of Parkinson’s disease.

The findings — by a team of researchers from the University of Florida in Gainesville and Lund University in Lund, Sweden — were published in March in the online journal of the Proceedings of the National Academy of Sciences.

Neuroscientists Anders Bjorklund of Sweden and Ronald Mandel from UF said the strategy that proved effective in the rodents is not a cure for Parkinson’s disease but is expected to lead to a better method for delaying and controlling symptoms of the progressively disabling condition.

“The simultaneous delivery of two selected genes, coupled with a powerful gene-activating agent, works like a pump to prime the production of L-dopa, which is then converted into dopamine by appropriate nerve cells in the brain,” said Mandel, a professor of neuroscience with UF’s McKnight Brain Institute and the UF Genetics Institute.

Dopamine is a neurotransmitter that plays a lead role in coordinating limb movements.

Limb impairments were completely reversed in rats that had near-total Parkinsonian lesions on only one side of the brain, meaning that some of their dopamine-producing cells remained intact. These partial lesions mimic the kind of damage found in people with the disease, according to the scientists. Even in the rats with complete destruction of dopamine-producing cells, the delivery of gene therapy resulted in a limited amount of restored motor function.

“Quite frankly, I was surprised by this successful outcome, since our previous experiments in the same animal model failed to result in restored motor function,” said Mandel, adding that one key to success was to figure out how much L-dopa the corrective genes need to generate to produce long-lasting functional effects.

The experiment that helped the rats regain motor function involved a single injection of two different genes, each packaged separately along with the selected gene promoter in a gene-transport molecule (vector). Both genes code for enzymes essential to triggering production of L-dopa.

Based on prior discoveries by Bjorklund, the researchers injected these genes into the striatal region of the forebrain, the destination point of dopamine-producing cells. When the injected vectors land in this area, they deposit their payload of genes, which are “turned on” by the gene-promoter to initiate L-dopa production.

Videotapes of the rats moving about in tall clear-glass cylinders illustrate the spontaneous behavior regained after gene therapy. Initial tapes show healthy rats exploring the sides of the cylinder with their front paws while walking around on their hind legs. After the induction of Parkinsonian lesions, the rats can be seen dragging one limp and rigid front paw while exploring their environment with the normal front limb. In videos taken after gene therapy, the same rats demonstrate normal function of both front paws.

Mandel said the effectiveness of gene therapy in the Parkinsonian rats generates hope that the therapy can eventually be applied in humans, with the potential to double the time a person with Parkinson’s disease will respond well to standard medications. Typically a patient responds well to medication for three to five years, but the beneficial effects gradually diminish because side effects begin to reduce the therapeutic value of the drug.

“We anticipate gene therapy will offer a way to help patients with Parkinson’s disease live many years longer free of disabling symptoms,” Mandel said.

Ronald Mandel,

by Arline Phillips-Han

UF Helping Develop Wind-Resistant Homes


In an effort to protect Florida residents from hurricane devastation, the University of Florida has joined feceral agencies and private businesses to develop affordable wind-resistant homes.

The two-year project is part of a federal initiative to aid windstorm mitigation efforts in several states, said Pierce Jones, an energy extension specialist with UF’s Institute of Food and Agricultural Sciences. Jones helps coordinate efforts by UF, an architect, a builder, a mortgage lender, the Federal Emergency Management Agency (FEMA) and the U.S. Department of Housing and Urban Development (HUD).

Energy extension specialists Craig Miller, left, and Pierce Jones examine a cutaway model of a window while discussing how high winds can cause windows to fail at the three points - the frame, sash or glass.

“Hurricane Andrew in 1992 caused Florida’s housing industry to re-evaluate not only construction methods but also strategies for insuring and financing homes,” Jones said. “The Florida National Quality Demonstration Project is a comprehensive approach to these challenges.”

One long-range goal of the project is to persuade builders statewide to adopt new construction methods in hurricane-prone coastal areas, said Perry Green, an assistant professor with UF’s civil and coastal engineering department.

“Builders are convinced by results,” Green said. “We’ll need to prove our ideas work, that they’re cost effective and marketable. Ultimately, UF will develop educational programs to teach builders to use these ideas.”

He said the project currently focuses on designing homes that can withstand peak wind gusts of at least 140 mph, equivalent to Category 3 on the Saffir-Simpson Hurricane Scale, which ranks storms based on wind speed. Category 3 is the third-most severe ranking, with peak gusts of 141 to 165 mph.

“Since Jan. 1, 2002, more stringent wind-loading requirements have taken effect in coastal and inland areas,” said Craig Miller, a UF energy extension specialist in Gainesville. “Some one- and two-family dwellings will have to withstand peak gusts of 130 to 150 mph. So this project should be of interest to builders.”

Bill Zoeller, a senior architect with Steven Winter Associates, a Connecticut-based building systems research and design firm, is designing a prototype home with poured-in-place concrete exterior walls and light-gauge steel interior framing.

“We’re still developing some components, like impact-resistant windows, reinforced garage doors and roof attachments,” he said. “These homes should be affordable and sell for about the same as typical Central Florida construction.”

Designs for the prototype should be completed by next spring, said Kirk Malone, regional vice president of construction for Mercedes Homes in Melbourne.

“If all goes well, we hope to build a prototype soon afterward,” Malone said. “Eventually we’d like to develop several models, all incorporating the same wind-resistant features, and put them on the market commercially.”

The Florida effort is part of the federal National Quality Demonstration Project, created to address ongoing concerns about hurricane damage to the Gulf and Atlantic coasts, said U.S. Rep. Dave Weldon.

Funding for the project was provided by grants from FEMA and HUD, Weldon said.

Pierce Jones,

Perry Green,

Craig Miller,

by Tom Nordlie

Feline AIDS Vaccine Headed To Market

A University of Florida researcher who helped discover the feline immunodeficiency virus has developed a feline AIDS vaccine that could be available to cat owners by this summer.

The vaccine — developed by Janet Yamamoto, a professor at UF’s College of Veterinary Medicine — was approved for sale by the U.S. Department of Agriculture (USDA) in March. Kansas-based Fort Dodge Animal Health has received a license to market the product, which is expected to be available through veterinarians as early as this summer.

“This is the first product to ever be made available for preventing this viral infection,” said USDA spokesperson Jim Rogers. “For that matter, it’s the first time any type of vaccine to prevent any type of animal immunodeficiency virus infection has ever been approved for commercial use.”

FIV has many biological similarities to the human immunodeficiency virus, or HIV, the cause of human AIDS. For that reason, approaches to protecting cats from FIV are relevant to the development of human AIDS vaccines.

Although estimates vary, between 2 percent and 25 percent of the global domestic cat population is believed to be infected with the virus, according to the USDA.

“It is generally believed that transmission of FIV takes place through bite wounds inflicted during fighting, and no cat-to-human transmission has ever been reported,” Yamamoto said. “However, we are looking into this possibility.”

Cats with FIV develop symptoms in three stages.

“In the acute initial stage, cats show loss of appetite, transient fever, lethargy and have a low white blood cell count,” Yamamoto said. “Many cats recover from the initial phase and become lifelong carriers of the virus. In the second stage, the cats exhibit no overt symptoms. In the third stage, however, cats experience severe weight loss, and secondary infections that become resistant to treatment or frequently recur.”

Yamamoto’s vaccine technology is based on viruses from cats called “long-term nonprogressors,” so named because the animals have been infected with FIV but take a long time to show symptoms of the disease.

“These strains take a long time to cause disease, and once symptoms do occur, the disease is milder,” said Yamamoto. “Instead of rapidly destroying the immune system, the virus hangs around at low levels in these cats and stimulates the immune system, allowing it to respond more effectively.”

Yamamoto and Niels Pedersen of the University of California, Davis first discovered the feline virus in 1986. Yamamoto has continued to study the virus and its pathogenesis, which provided the foundation for developing the vaccine.

UF and the UC Davis jointly hold the patents for the FIV vaccine, and the two institutions have reached agreement with Fort Dodge to explore the use of the FIV vaccine for commercial applications, said Bin Yan, assistant director of life sciences at UF’s Office of Technology Licensing.

Fort Dodge Animal Health is a division of New Jersey-based Wyeth Pharmaceuticals.

Janet Yamamoto,

by Sarah Carey

Adult Stem Cells Regenerate Heart Tissue In Mice

In a study that may eventually provide hope for millions suffering from disease-damaged hearts, University of Florida researchers have transformed adult bone marrow stem cells from humans into heart muscle cells that remained healthy and functioning in mice for more than two months.

“Knowing that the cells are able to be transplanted successfully into the heart may one day enable the application of this stem cell population to human disease,” said Dr. Barry Byrne, co-director of UF’s Powell Gene Therapy Center and one of the authors of the journal article published in Circulation, a journal of the American Heart Association.

Unlike skeletal muscle, adult cardiac muscle damaged by deficient blood flow lacks the ability to regenerate, resulting in irreversible heart tissue death. UF scientists found that within two weeks after human bone marrow stem cells were injected into the coronary arteries of a type of immunodeficient mice, the stem cells differentiated into heart muscle and adopted many of the characteristics of the surrounding tissue. The study was conducted in an effort to expand knowledge about the transformational abilities of human bone marrow cells, but UF researchers say the technique may be able to be tested within two to three years in people with heart damage.

“We were able to examine the new cells in the heart tissue and see the characteristic patterns of protein expression in cardiac cells,” said Byrne, an associate professor in the UF College of Medicine departments of pediatrics, and molecular genetics and microbiology. Byrne conducted the study in conjunction with scientists from the Johns Hopkins School of Medicine and Baltimore-based Osiris Therapeutics. It was funded by  Osiris and the National Institute of Standards and Technology.

“These findings provide a detailed snapshot of the regenerated stem cells’ behavior in the heart tissue, far beyond patterns of gene expression,” Byrne said.

In the current study, a type of stem cells called human mesenchymal stem cells — which give rise to skeletal muscle tissue — that were derived from the bone marrow of four volunteers differentiated into heart muscle cells called cardiomyocytes in mice that lacked the ability to mount an immune response against the human cells. The stem cells were injected into the coronary arteries of the left ventricle, and a portion of them settled in the heart.

At various points over a two-month period, the heart tissue was analyzed to determine implantation and differentiation of the stem cells using marker genes and immunofluorescent staining for common cardiac proteins.

In 12 of 16 mice, implanted stem cells were found dispersed throughout the myocardium at four days. Over time, these cells began to take on the form and function of the surrounding cardiomyocytes and, after 14 days, became indistinguishable from the rod-shaped heart muscle cells. Byrne and other UF scientists are continuing the research and now are studying the ability of human bone marrow stem cells to regenerate heart muscle cells in animals with various types of heart muscle injury, such as cardiomyopathy.

In an effort to improve safety and effectiveness, they also are investigating an alternative method of delivering the stem cells to damaged heart tissue in conjunction with gene therapy vectors now used primarily to carry corrective genes.

Barry Byrne,

by Paula Rausch

UF Researcher: Beach Mice Face Extinction

The twin menaces of hurricanes and beachfront development appear poised to wipe out Florida’s most diminutive coastal native — the beach mouse — according to new research led by a University of Florida scientist.

Scientists at UF and Auburn University have concluded that the few remaining populations of beach mice on the Florida and Alabama coasts are in “substantial danger” of extinction from hurricanes and continuing loss of habitat to development. In research on four remaining populations — including the last known populations of a Perdido Key subspecies — the researchers predicted the populations have a 37 to 57-percent chance of extinction in 25 years and a 59 to 80-percent chance in 50 years. Their conclusions already are being borne out: Since the research was conducted, one of the Perdido Key populations has gone extinct, although another population of the subspecies has been reintroduced elsewhere on the key.

“We asked, ‘What would be the chance that beach mice will persist in the future if we consider the effects of catastrophic events such as hurricanes?’” said Madan Oli, a UF assistant professor of wildlife ecology and conservation and lead author of a paper on the research that appeared this year in the journal Biological Conservation. “Unless we increase our efforts to conserve habitat and take other measures, the answer doesn’t look too good.”

The beach mouse, Peromyscus polionotus, is small and nocturnal. It ranges in color from nearly white to brown, depending on the color of the surrounding soil. The mice once occurred throughout the coastal regions of Alabama and western Florida, but the spread of commercial and residential development has slashed their numbers and fragmented their populations. Today, only about a dozen small populations remain on the Gulf coast, composed of four endangered subspecies and one not listed as endangered or threatened.

Oli, Nicholas Holler of the Alabama Cooperative Fish and Wildlife Research Unit and Michael Wooten, an associate professor of biology at Auburn, focused on four populations near the Florida-Alabama state line.

To gauge the populations’ chance of survival, the researchers drew on data gathered by Wooten and other scientists who had spent several years in the 1980s and 1990s using live traps to collect and count mice at the sites. They analyzed the data with computer models using a method known as population viability analysis.

Their results are not promising. For one thing, the scientists’ estimates of actual numbers of remaining mice are quite low. At only one of the four sites did estimates top 1,000 mice during the six or more years when the populations were sampled, while low numbers for the years reached 50 mice or fewer for all the sites.

“I think if you take a particular population, almost any of them has a high probability of extinction within 100 years — that’s probably a normal function of their biology,” Wooten said. “It’s just that now, with so few populations, that fluctuation poses a threat to the species.”

The problem is that hurricanes have the potential to wipe out mouse populations — thanks to coastal development, Oli said.

On undisturbed lands, beach mice live on dunes but retreat to nearby scrub dune habitat when a hurricane destroys their burrows or temporarily eliminates seeds such as sea oats that constitute their diet, Oli said. While most frontal beach zones remain intact, scrub habitat is ideal for beachside development and has become increasingly scarce as condominiums and houses sprout along the coast. As a result, the mice have no refuge.

Not only that, in undisturbed areas, mice living in scrub habitat can repopulate frontal dunes after catastrophes, whereas if the scrub is gone, that option is closed off.

“You’re saving beautiful as well as valuable habitat,” Wooten said.

Madan Oli,

by Aaron Hoover

Popular Kingsnakes Are Disappearing From Florida

The kingsnake, so named because it eats poisonous snakes and is immune to their venom, is rapidly disappearing from Florida, according to new research by a University of Florida scientist.

Once common throughout the state, the kingsnake has vanished from many Florida counties, said Kenneth Krysko, a UF student who researched the snake’s ecological status as part of his doctoral dissertation. Causes may include habitat loss, overzealous collection by reptile fans or dealers and loss of genetic diversity.

“They’re not nearly as abundant as they used to be, and we don’t know why,” said F. Wayne King, a professor and herpetologist at the Florida Museum of Natural History and the chairman of Krysko’s dissertation committee.

Kingsnakes’ appearances vary widely, but most kingsnakes have light-colored bands, blunted heads and reach a maximum length of slightly over six feet.

Kingsnakes are unusual among snakes because their diet includes other snakes, including poisonous ones such as rattlesnakes, and they are immune to snake venom. Kingsnakes are also relatively docile, a quality that makes them popular in the reptile trade and has contributed to their plight, Krysko said.

For his research, Krysko culled scientific literature, museum collections and scientists’ field notes for examples of kingsnake sightings or records in Florida dating back to 1858. The resulting geographic database suggests that, while the snakes once occupied at least 54 of Florida’s 67 counties, their range has shrunk considerably in recent decades. Records indicate the existence of kingsnakes in only 23 counties between 1990 and 1999, despite an increase in the number of collectors and herpetologists in the field.

Krysko said loss of the snake’s favored habitat in woods near water bodies is one factor contributing to its decline. Much of the habitat that remains is disconnected, meaning the snakes cannot share genes with neighboring populations.

Another potential threat is the spread of non-native fire ants, which some scientists believe target kingsnake eggs and young. Still another danger is that, as predators at the top of the food chain, kingsnakes may ingest damaging or deadly levels of heavy metals and pesticides, Krysko said.

There were at least four formerly large populations of kingsnakes statewide, including at Paynes Prairie in Alachua County. King said it was easy to find kingsnakes on the prairie in the 1950s and early ‘60s.

“Now, they’re gone,” he said. “They don’t exist on the prairie as far as we know.”

Only one kingsnake population, south of Lake Okeechobee in the sugar cane plantations, remains healthy, Krysko said. Kingsnakes flourish in this area because the sugar cane fields and irrigation canals support large populations of snakes and other rodents, he said. Ironically, the planned Everglades restoration threatens this population because it will replace some sugar cane farms, he said.

“We’ve created this great habitat there for this species that has declined everywhere else,” he said.

Krysko and King said the study’s findings indicate that the kingsnake should be protected by the state of Florida. Florida currently has two snakes on its “threatened” list: the Atlantic salt marsh snake and eastern indigo snake.

Kenneth Krysko,

by Aaron Hoover