Study finds that some animals feel regret

Animals have feelings too – or so a recent study at Duke University says.

The first study tested both chimpanzees and monkeys who traded tokens for cucumbers. The primates that noticed one of their peers was receiving a tastier treat in exchange for his tokens and reacted negatively.

“I think animals do experience regret, as defined as the recognition of a missed opportunity,” said Dr. Sarah Brosnan, a psychologist at Georgia State University. “In the wild, these abilities may help them to recognize when they should forage in different areas or find a different cooperative partner who will share the spoils more equitably.“

A more recent study used data from brain scans of monkeys attempting to merit a cup of juice by guessing where researchers had hidden it. If the monkeys‘ answers were wrong, they were shown the correct hiding place. The monkeys then changed subsequent guesses, displaying what researchers called a “would-have, could-have, should-have” reaction.

(Source: nytimes.com)

More information on the origins of swine flu

There may soon be a vaccine against the dreaded H1N1 flu due to research from the U.S. Centers for Disease Control and Prevention and the University of Cambridge, UK.

The researchers analyzed 76 isolates of the virus from Mexico and the U.S. and found that the virus was actually first found in swine in 1930. The virus was extremely similar to a 1918 pandemic in humans.

The information eventually led researchers to discover that the virus outbreak in April had two genes from avian influenza, three from North American swine, and one from humans.

The small amount in variation makes the virus easier to develop a vaccine for, researchers said.

(Source: sciencemag.org)

Bacterial samples from human body reveal a range of microbe findings

Some of the dirtiest places in the world are right under our fingertips – as well as on our noses, ears and in our upper thighs.

Elizabeth Grice from the National Human Genome Research Institute surveyed 10 healthy volunteers, swabbing samples of skin from 20 different places on the body.

The study found that the inside and the crease beside the nose has the largest collection of microbes. She also found a large amount of bacteria the inguinal crease – the place where the leg meets the groin – and just inside the ear.

Other hot spots for bacteria were places both dry and moist, as opposed to oily. The largest diversity of bacteria is located on the forearm, where there are an average of 44 different species.

The findings may assist in studies regarding skin disorders that tend to be specific to areas of the body.

(Source: genome.cship.org)

LAUREN STEUSSY can be reached at campus@theaggie.org. 

Recent research from the UC Davis Center for Healthcare Policy and Research has found that women who have previously been treated for cervical intraepithelial neoplasia (CIN), also known as cervical dysplasia, are more prone to contracting the disease a second time or developing invasive cervical cancer.

The data from the study starting in 1986 encompasses a total of 37,142 women from the British Columbia Cancer Agency who were previously treated for varying degrees of CIN. The study also looks at a comparative population of 71,213 women who were never treated for, nor had CIN.

“We looked at the rate of recurrence of abnormal biopsy in both groups and we looked to see the age of the women, what they were treated with and the original grade of the abnormality affected the recurrence rate,” said Joy Melinkow, author of the study and [doctor at The Department of Family and Community Medicine, Center for Healthcare Policy and Research at UC Davis.

The varying grades of the disease were each treated differently. The women who were affected with a grade two or three of the disease had cone biopsy, loop electrosurgical excision procedure, laser excision or vaporization, or cryotherapy treatment – the freezing of abnormal cells. Women with grade one of the disease could undergo optional treatment.

“Women who had been treated over and especially in the first six years had a higher rate of recurrence than the women that were never treated. And the highest rate of recurrence was in women who had been treated when they had a higher grade, treated with a freezing treatment, and were over 40,” Melinkow said.

The results show that women in the CIN sample were younger than the women in the control sample, whose treatment was often for a CIN with a grade of three.

“It’s not surprising that a more severe abnormality would be more likely to occur. The freezing treatment would be more likely to have recurrences than excision, one reason being that the freezing did not completely eliminate the abnormal cells,” Melinkow said.

Melinkow pointed out that the study helps to guide future treatment in patients who have been previously diagnosed.

UC Davis has the only cancer center in inland Northern California designated by the National Cancer Institute. The center cares for an estimated 9,000 adults and children each year from throughout the Central Valley and inland Northern California, said Dorothy Griffith-Pease, spokesperson for the National Cancer Institute in an e-mail interview.

“Joy Melnikow’s work in cervical cancer is an important component of the cancer center’s work to better understand long-term risks associated with certain cancers – research which ultimately can guide and improve treatment options,“ Griffith-Pease said.

Melinkow’s research could potentially help doctors to understand cancer’s effects and the potential dangers present in incorrectly treating the preliminary effects of the disease.

SADAF MOGHIMI can be reached at campus@theaggie.org. 

A new stem cell lab opened May 18 at the UC Davis veterinary school, providing revolutionary improvements in treating horses with extensive injuries, including bone fractures and damage to ligaments, tendons and joints.

The lab, which serves solely as a treatment facility, injects healthy stem cells into the damaged tissue of an injured horse, thereby healing even the most traumatic of injuries.

“Right now we’re offering this type of therapy often in our most severe or chronic lesions, where there really wasn’t any other hope,” said Dori Borjesson, veterinary clinical pathologist and faculty member working in the regenerative medicine lab. “Horses would often have to retire from racing, but we’re seeing animals go back and return to health and fitness that basically would not be expected to do so before this lab opened.”

Normally, when an animal has a lesion due to traumatic injury, new cells form and replace the damaged tissue. However, scar tissue formation also occurs as part of this healing process, and scar tissue is not as strong as the tissue had been before the injury. Injection of stem cells into the site of injury bypasses this process, allowing the damaged cells to heal such that all of the new cells that are grown are no less strong than they had been.

“With stem cells you can repair a tendon with tendon cells, not scar tissue,” said Sean Owens, veterinary clinical pathologist and faculty member. “Stem cells would be able to go in there and grow into normal tendon tissue, as opposed to forming a scar, which is inherently weaker than the tendon cells.“

This type of treatment exemplifies regenerative medicine, Borjesson said.

“The potential for cells to regenerate the cells to their original tissue as opposed to forming a scar … and help organ structures recreate themselves as they once were,” she said.

The veterinarians stressed that embryonic stem cell usage – a highly controversial area of biomedical research and treatment – is not employed at this laboratory. Instead, undifferentiated blood cells – mesenchymal cells and hematopoietic cells – are taken from the bone marrow of a healthy horse and are injected into the site of lesion of the injured horse.

Bone marrow-based stem cell transfer confers a great advantage: Because these cells are not mature, the immune system of the patient that receives the stem cells does not reject the cells, as is often seen in organ transplants.

“One of the great things about these cells is that you don’t have to [put the horse] on immunosuppressant drugs, which can lead to other complications,” Borjesson said. “That is the potential wonder of these cells.“

But the use of stem cells to treat injuries is not equine-specific. There are prospects that these same types of cells in small animals and humans can treat their lesions, too.

“Stem cell use lends itself to humans, dogs and cats,” Owens said. “One of the things that is very beneficial is that our success directly influences the success of human researchers. If we can heal tendons or ligaments in a horse, researchers will be able to directly use what we have discovered and heal ligaments in humans. The work we do is directly applicable to healing human disease.“

Stem cells will hopefully someday be able to treat certain chronic diseases in animals and humans alike, for which there currently exists no cure, Owens added.

“We would like to be able to put [these cells] into the patient who has diabetes. If we can make those cells produce insulin again, they are no longer diabetic. Where we are now is trying to figure out how to speak the same language as these cells … and be able to tell them what we want them to do.“

Borjesson agreed, adding that currently stem cells are used solely in injuries, but are not limited to them in any circumstances.

“There is also research going on in spinal chord injuries, oncology and other diseases. And all the donor typing can be excluded, and certain retinas, livers and lungs don’t have to be transplanted; we just use these cells to benefit the patient,” Borjesson said.

MICHAEL MILLER can be reached at campus@theaggie.org. 

Eggs produced in a study led by researchers at UC Davis and Michigan State University will supply McDonald’s U.S.A. by 2011.

The commercial-scale study will include tens of thousands of hens to examine the sustainability impacts of various housing alternatives for egg-laying hens in the U.S. These impacts include animal welfare, environmental, food safety and economic factors.

“This study will involve collecting scientific data from different laying hen production systems (conventional cages; enriched environments containing nest boxes, perches and a dust-bathing/scratching area; and non-cage systems),” said Professor Joy Mench, director of the UC Davis center for animal welfare, in an e-mail interview.

Commercial-scale facilities will be constructed with these different housing systems and the data collected will provide information to major retailers to help them make decisions about what types of eggs to purchase in the future.

“This is a welcome initiative for egg purchasers like McDonald’s who want to consider all of the sustainability impacts when it comes to buying eggs,” said Dan Gorsky, McDonald’s senior vice president, North America Supply Chain Management, in a press release. “It is our intention for eggs produced as part of this study, including cage free eggs, to partially supply McDonald’s U.S.A. by 2011.“

McDonald’s, the American Humane Association, American Veterinary Medical Association, USDA’s Agriculture Research Service, Cargill Inc. and the Center for Food Integrity will also advise the study.

“There’s a very compelling need for a study of this scope,“ said Marie Wheatley, president and CEO of the American Humane Association, in a press release. “While scientists indicate there are benefits for laying hen birds to be able to demonstrate more natural behaviors associated with a cage-free environment, there are open questions on other animal welfare matters such as feather pecking and mortality rates.“

The study lies on the heels of Proposition 2, a law passed November 2008 in California that will take effect January 2015. It requires that hens used for commercial egg production must be given enough space to lie down, stand up and fully extend their limbs.

“The major impact of this proposition will be on laying hens and laying hen producers,” Mench wrote in a release about Prop 2. “The California egg industry produces almost 5 billion eggs per year from almost 20 million laying hens. About 95 percent of these hens are housed in conventional cages, and 5 percent are housed in non-cage (cage free) systems, including the hens that produce organic eggs.“

But there are advantages and disadvantages to each system – issues the study will work to assess and solve according to Dr. Janice Swanson, Michigan State University, in an e-mail interview.

“No use having a system that perfectly accommodates animal welfare but produces a significant negative impact to the environment – that would not be sustainable,” Swanson said.

“Instead, let’s evaluate then choose or develop systems that not only accommodate the behavior of the hen but maintains her in good health, is environmentally responsible, produce a healthy egg product that can be transferred through the supply chain with integrity, is affordable and allows the farmer to stay in business,” he said.

While the specific timetable and cost of the effort has not yet been determined, and participating experts are still working toward standards for the various housing types, researchers are confident the work will lead to information hopeful for the future of sustainable farm systems.

“Very few studies have taken a fully integrated approach to considering the other aspects of the system and at a commercial scale of production,” Swanson said. “We are working to advance our scientific understanding of how changes impact the hen and the different features of a system, how we can improve current systems, and to look ahead at forming the foundation for the next generation of sustainable farm systems.“

DAVID LAVINE can be reached at campus@theaggie.org.

Researchers have successfully used adult human stem cells to coax new blood vessel growth and restore blood flow in mice with artery damage to their legs.

The study provides important clues behind the therapeutic properties of these cells, which have already shown promise in early human trials for treating peripheral arterial disease (PAD), a debilitating condition that can require amputation of affected limbs.

A unique fraction of stem cells from human bone marrow boosted recovery in mice that had a femoral artery removed beforehand to cut off blood supply to one of their legs. Researchers isolated the cells based on high expression of an enzyme called aldehyde dehydrogenase (ALDH high), which they then labeled with fluorescent trackers before injection into the mice.

Imaging techniques showed that the cells targeted the limbs with reduced blood supply, otherwise known as ischemia. These cells enhanced both blood flow and new blood vessels compared to mice that received unpurified bone marrow cells or fractions without the special stem cells.

“Faster blood flow recovery is likely to translate into better tissue recovery,” said study co-author Daniel Link, an associate professor at Washington University School of Medicine in St. Louis, in an e-mail interview. “One of the major limitations to cell-based therapeutic angiogenesis is our lack of understanding of the cell types that mediate this response. This study identifies a new subtype based on an easy to perform assay (ALDH activity) that can stimulate angiogenesis. Isolating ALDH high cells prior to delivery to ischemic tissue may dramatically improve efficacy.“

The researchers believe their study, published in the May 21 issue of the journal Blood, supports the potential use of these cells as a new line of treatment for PAD. The chronic condition, which is common in older adults with diabetes, is caused by build up of fatty deposits that block arteries supplying blood to the extremities and some organs. In its most severe form, called critical limb ischemia (CLI), poor circulation in the legs can cause pain, weakness and tissue damage.

“Unfortunately, some of our PAD patients may have had open bypass surgery or less invasive procedures [like stents] that failed to salvage their limbs. Other patients can have such severe arterial disease where a bypass or revascularization procedure is not possible,” said Nasim Hedayati, an assistant professor at the UC Davis department of surgery who was not involved in the study, in an e-mail interview.

“Therefore, the possibility that advances in stem cell research may one day help form new blood vessels in ischemic limbs is very exciting. Being able to prevent a patient from losing a limb can greatly affect his or her quality of life and survival.“

The study results are directly relevant to humans, the researchers said.

“We use immune deficient mice so we can study the function of human cells in an animal model of CLI. These studies allow for ‘proof of principal‘ that human cells can regenerate blood vessels after transplantation,” said senior author David Hess, an assistant professor at the University of Western Ontario, in an e-mail interview.

Study author Jan Nolta likens the ALDH high cells to “paramedics of the body” because they directly migrate to tissues damaged by reduced blood flow and secrete factors that promote angiogenesis. She and her colleagues recently submitted a report for publication in which they identified the key molecules – called chemokines – that drive this unique homing behavior.

“If we knock out the receptors for those [chemokines] in the stem cells, then the stem cells can’t migrate anymore,” said Nolta, a professor of internal medicine and director of the UC Davis Stem Cell Program.

Unlike embryonic stem cells, which can replace any type of specialized cell in damaged tissue, the adult stem cells in the study did not stick around once they initiated repair.

“After a couple weeks, they really aren’t needed anymore because the tissue itself takes over,” Nolta said. “They’re just there for a couple of weeks to tip the balance towards healing instead of [cell death].“

The researchers have not yet isolated a single cell type or secreted factor responsible for the ALDH high population’s regenerative properties, but they are confident that the intact stem cell mixture will suffice for clinical purposes.

“If we can understand how the stem cells induce regeneration, we will be better equipped to develop rational clinical therapies for a wide variety of diseases,” Hess said.

ELAINE HSIA can be reached at campus@theaggie.org.