HIV Is Evolving To Evade Human Immune Responses

HIV is evolving rapidly to escape the human immune system, an international study led by Oxford University has shown. The findings, published in Nature, demonstrate the challenge involved in developing a vaccine for HIV that keeps pace with the changing nature of the virus.The extent of the global HIV epidemic gives us a unique opportunity to examine in detail the evolutionary struggle being played out in front of us between an important virus and humans,’ says lead researcher Professor Philip Goulder of the Peter Medawar Building for Pathogen Research at Oxford University.

‘Even in the short time that HIV has been in the human population, it is doing an effective job of evading our best efforts at natural immune control of the virus. This is high-speed evolution that we’re seeing in the space of just a couple of decades.’

The study better describes HIV's ability to adapt by spelling out at least 14 different "escape mutations" that help keep the virus alive after it interacts genetically with immunity molecules that normally attack HIV.

"Key genetic regions of HIV introduced into individuals of different ancestry in different places have been evolving to a greater or lesser degree according to inherited factors controlling immune response," said Richard Kaslow, M.D., a professor in the UAB School of Public Health and a co-author of the study. "If HIV adapts differently in genetically distinct hosts, the challenge ahead in vaccine design is formidable," he said.

HIV has already killed 25 million people, and an estimated 33 million are currently infected. However, HIV does not kill all people at the same rate. On average, an adult with HIV will survive for ten years without anti-HIV drugs before developing AIDS. But some people will progress to AIDS within 12 months while others can make effective immune responses to the virus and survive without any anti-HIV therapy for over 20 years.

Genes encoding a key set of molecules in the human immune system called the human leucocyte antigens (HLA) are critically important. HLA determine the progress of many infectious diseases including HIV, and enable the recognition and killing of HIV-infected cells. Humans differ from each other in the exact HLA genes they have, and small differences can make the difference in how long it takes to progress to AIDS.

The research team set out to determine whether HIV is adapting to human immune responses. They looked at HIV genetic sequences in different countries around the world, including the UK, South Africa, Botswana, Australia, Canada, and Japan, wanting to see whether the HIV sequences could be related to the different HLA genes present in the different populations.

The collaboration between Oxford University, the Ragon Institute at Massachusetts General Hospital, Kumamoto University in Japan, the Royal Perth Hospital and Murdoch University in Australia and others analysed the genetic sequences of the HIV virus and human leucocyte antigen (HLA) genes in over 2,800 people.

Mutations that allow HIV to get round immune responses directed by a particular HLA gene were found more frequently in populations with a high prevalence of that HLA gene. This is strong evidence for HIV adaptation to the human immune system at the level of populations.

‘Where a favourable HLA gene is present at high levels in a given population, we see high levels of the mutations that enable HIV to resist this particular gene effect,’ says author Professor Rodney Phillips, co-director of the James Martin Institute for Emerging Infections at Oxford University. ‘The virus is outrunning human variation, you might say.’

‘The temptation is to see this as bad news, that these results mean the virus is winning the battle,’ says Professor Goulder. ‘That’s not necessarily the case. It could equally be that as the virus changes, different immune responses come into play and are actually more effective.’

The results are important because it is our most effective immune responses that vaccines against HIV would try and boost to a level that would protect against the virus.

‘The implication is that once we have found an effective vaccine, it would need to be changed on a frequent basis to catch up with the evolving virus, much like we do today with the flu vaccine,’ explains Professor Goulder.

‘In this anniversary year of Darwin’s birth, we are accustomed to think of evolution happening over thousands, tens of thousands and even millions of years,’ says Professor Goulder. ‘But we are seeing changes in HIV, and our immune response to the virus, in just a couple of decades.’

The work was funded by a number of organisations including the Wellcome Trust, the Medical Research Council, the US National Institutes of Health, and Oxford’s James Martin 21st Century School.

'Obesity Gene' Involved In Weight Gain Response To High-fat Diet Identified

Scientists have determined that a specific gene plays a role in the weight-gain response to a high-fat diet.The finding in an animal study suggests that blocking this gene could one day be a therapeutic strategy to reduce diet-related obesity and associated disorders, such as diabetes and liver damage, in humans.

The researchers found that a diet rich in fat induced production of this gene, called protein kinase C beta (PKC beta), in the fat cells of mice. These mice rapidly gained weight while eating a high-fat diet for 12 weeks.

On the other hand, mice genetically engineered to lack PKC beta gained relatively little weight and showed minimal health effects after eating the same high-fat diet.

In comparing the effects of the high-fat diet and a regular diet, the scientists found that mice fed the high-fat diet produced more PKC beta in their fat tissue than did mice eating a regular diet.

“So we now know this gene is induced by a high-fat diet in fat cells, and a deficiency of this gene leads to resistance to fat-induced obesity and related insulin resistance and liver damage,” said Kamal Mehta, senior author of the study and a professor of molecular and cellular biochemistry in Ohio State University’s College of Medicine.

“It could be that the high-fat diet is a signal to the body to store more fat. And when that gene is not there, then the fat storage cannot occur.”

Though the complete mechanism remains unknown, the research to date suggests that rather than storing fat, mice lacking the gene burn fat more rapidly than they would if the PKC beta were present, Mehta said.

The research is available online in the journal Hepatology and is scheduled for later print publication.

Mehta and colleagues previously had created the hybrid mouse model by cross-breeding mice deficient in PKC beta with the C57 black mouse, a common animal used in research for studying diabetes and obesity. Despite the propensity for obesity from their original genes, the new mice lost weight while eating up to 30 percent more food than other mice.

In the earlier study, the mice ate a regular diet. In this new study, the researchers fed PKC beta-deficient and normal mice either a diet in which 60 percent of calories were derived from fat – the high-fat diet – or a standard diet in which 15 percent of calories came from fat. In the typical American diet, about 40 percent of calories are derived from fat.

The normal mice on the high-fat diet showed weight gain within three weeks, a trend that continued throughout the 12-week study. The PKC beta-deficient mice on the same diet gained less weight even while appearing to be extra hungry and eating more calories than the normal mice – meaning their lower body weight was not the result of eating less.

Of animals eating the high-fat diet, the fat tissue and livers in the normal mice were larger than those in the PKC beta-deficient mice, as well. The livers of the normal mice were on average about 50 percent larger than the livers in mice lacking the gene. And the white fat tissue – the tissue in which PKC beta was expressed as a result of the high-fat diet – was almost three times as heavy in the normal mice as in the PKC beta-deficient mice.

The protein-deficient mice were able to clear insulin to regulate blood sugar more rapidly than normal mice after eating the high-fat diet, meaning avoiding obesity also allowed them to avoid development of insulin resistance associated with diabetes, said Mehta, also an investigator in Ohio State’s Davis Heart and Lung Research Institute.

“Obesity leads to liver damage and to diabetes. So if we can take care of obesity associated with a high-fat diet, we can also take care of most of the related disorders,” Mehta said.

A separate component of the current study further showed that mice engineered to be obese also had about 500 percent more of the gene in their fat cells than did normal mice. Mehta and colleagues have assembled a team that includes an endocrinologist, bariatric surgeon and molecular biologist to examine human fat tissue from obese and lean patients to see if levels of PKC beta are elevated in obese humans, as well.

“It is very likely that this gene may be involved in a predisposition to obesity,” he said.

Knowing the gene is responsive in the fat cells is important to figuring out how to suppress its action. Future research will involve deleting the gene from fat cells in mice to see if these new mice have the same lean body type as mice that are completely deficient of PKC beta throughout their entire genome.

“We are generating more mouse models to vary expression of this gene and study the consequences of that on obesity and related disorders,” Mehta said.

So far, mouse models lacking the protein have not shown any damaging side effects related to the suppression of the gene, Mehta said. He speculates that PKC beta could be a so-called “thrifty” gene left over from humans’ days as hunter-gatherers, when the body needed to retain fat for survival.

This work is supported by the National Institutes of Health.

Co-authors on the paper were Wei Huang and Rishipal Bansode of the Department of Molecular and Cellular Biochemistry, and Madhu Mehta of the Department of Internal Medicine, all at Ohio State.

Soybean Product Fights Abnormal Protein Involved In Alzheimer’s Disease

A vegan food renowned in Asia for its ability to protect against heart attacks also shows a powerful ability in lab experiments to prevent formation of the clumps of tangled protein involved in Alzheimer’s disease, scientists in Taiwan are reporting. Rita P. Y. Chen and colleagues point out that people in Asia have been eating natto — a fermented food made from boiled soybeans —for more than 1,000 years. Natto contains an enzyme, nattokinase, that has effects similar to clot-busting drugs used in heart disease.Nattokinase is sold a dietary supplement to improve the body’s circulatory system.

The scientists term this the first study on whether nattokinase also can dissolve amyloids. Those tangled proteins are involved in Alzheimer’s disease and several other health problems.

In the study, the nattokinase degraded several kinds of amyloid fibrils, suggesting its possible use in the treatment of amyloid-related diseases. “Moreover, since natto has been ingested by humans for a long time, it would be worthwhile to carry out an epidemiological study on the rate of occurrence of various amyloid-related diseases in a population regularly consuming natto,” the scientists say.

Carbon Nanotubes That Look Like Asbestos, Behave Like Asbestos, Could Lead To Asbestos-related Disease

A major study published in Nature Nanotechnology suggests some forms of carbon nanotubes -- a poster child for the "nanotechnology revolution" -- could be as harmful as asbestos if inhaled in sufficient quantities.The study used established methods to see if specific types of nanotubes have the potential to cause mesothelioma -- a cancer of the lung lining that can take 30-40 years to appear following exposure. The results show that long, thin multi-walled carbon nanotubes that look like asbestos fibers, behave like asbestos fibers.

Discovered nearly 20 years ago, carbon nanotubes have been described as the wonder material of the 21st Century. Light as plastic and stronger that steel, they are being developed for use in new drugs, energy-efficient batteries and futuristic electronics. But since their discovery, questions have been raised about whether some of these nanoscale materials may cause harm and undermine a nascent market for all types of carbon nanotubes, including multi- and single-walled carbon nanotubes. Leading forecasting firms say sales of all nanotubes could reach $2 billion annually within the next four to seven years, according to an article in the U.S. publication Chemical & Engineering News.

"This study is exactly the kind of strategic, highly focused research needed to ensure the safe and responsible development of nanotechnology," says Andrew Maynard, Chief Science Advisor to the Project on Emerging Nanotechnologies and a co-author on the paper. "It looks at a specific nanoscale material expected to have widespread commercial applications and asks specific questions about a specific health hazard. Even though scientists have been raising concerns about the safety of long, thin carbon nanotubes for over a decade, none of the research needs in the current U.S. federal nanotechnology environment, health and safety risk research strategy address this question."

Widespread exposure to asbestos has been described as the worst occupational health disaster in U.S. history and the cost of asbestos-related disease is expected to exceed $200 billion, according to major U.S. think tank RAND Corporation.

Anthony Seaton, MD, a co-author on the paper and a professor emeritus at the University of Aberdeen in the United Kingdom, says, "The toll of asbestos-related cancer, first noticed in the 1950s and 1960s, is likely to continue for several more decades even though usage reduced rapidly some 25 years ago. While there are reasons to suppose that nanotubes can be used safely, this will depend on appropriate steps being taken to prevent them from being inhaled in the places they are manufactured, used and ultimately disposed of. Such steps should be based on research into exposure and risk prevention, leading to regulation of their use. Following this study, the results of which were foreseen by the Royal Society in the U.K. in 2004, we can no longer delay investing in such research."

Researchers, led by Professor Kenneth Donaldson at the University of Edinburgh in the United Kingdom, examined the potential for long and short carbon nanotubes, long and short asbestos fibers, and carbon black to cause pathological responses known to be precursors of mesothelioma. Material was injected into the abdominal cavity of mice -- a sensitive predictor of long fiber response in the lung lining.

"The results were clear," says Donaldson. "Long, thin carbon nanotubes showed the same effects as long, thin asbestos fibers."

Asbestos fibers are harmful because they are thin enough to penetrate deep into the lungs, but sufficiently long to confound the lungs' built-in clearance mechanisms for getting rid of particles.

Donaldson stresses there are still pieces of the puzzle to fill in. "We still don't know whether carbon nanotubes will become airborne and be inhaled, or whether, if they do reach the lungs, they can work their way to the sensitive outer lining. But if they do get there in sufficient quantity, there is a chance that some people will develop cancer--perhaps decades after breathing the stuff," states Donaldson.

There is a silver lining to this research. According to Donaldson, "Short or curly carbon nanotubes did not behave like asbestos, and by knowing the possible dangers of long, thin carbon nanotubes, we can work to control them. It's a good news story, not a bad one. It shows that carbon nanotubes and their products could be made to be safe."

But Donaldson added that the present study only tested for fiber-like behavior and did not exonerate carbon nanotubes from damaging the lungs in other ways. "More research is still needed if we are to understand how to use these materials as safely as possible," he notes.

Carbon nanotubes are atom-thick sheets of graphite formed into cylinders. They may be formed from a single layer of graphite or they may consist of multiple concentric layers of graphite, resulting in multi-walled carbon nanotubes. While the diameter of a nanotube can vary from a few nanometers up to tens of nanometers, they can be hundreds or even thousands of nanometers long. Carbon nanotubes come in many forms, with different shapes, different atomic arrangements, and varying amounts and types of added chemicals--all of which affect their properties and might influence their impact on human health and the environment.

"This is a wakeup call for nanotechnology in general and carbon nanotubes in particular," says Maynard. "As a society, we cannot afford not to exploit this incredible material, but neither can we afford to get it wrong--as we did with asbestos."

Technique Tricks Bacteria Into Generating Their Own Vaccine

Scientists have developed a way to manipulate bacteria so they will grow mutant sugar molecules on their cell surfaces that could be used against them as the key component in potent vaccines.Any resulting vaccines, if proven safe, could be developed more quickly, easily and cheaply than many currently available vaccines used to prevent bacterial illnesses.

Most vaccines against bacteria are created with polysaccharides, or long strings of sugars found on the surface of bacterial cells. The most common way to develop these vaccines is to remove sugars from the cell surface and link them to proteins to give them more power to kill bacteria.

Polysaccharides alone typically do not generate a strong enough antibody response needed to kill bacteria. But this new technique would provide an easy approach to make a small alteration to the sugar structure and produce the polysaccharide by simple fermentation.

“We are showing for the first time that you don’t have to use complicated chemical reactions to make the alteration to the polysaccharide,” said Peng George Wang, Ohio Eminent Scholar and professor of biochemistry and chemistry at Ohio State University and senior author of the study. “All we need to do is ferment the bacteria, and then the polysaccharides that grow on the surface of the cell already incorporate the modification.”

The research is scheduled to appear in the online early edition of the Proceedings of the National Academy of Sciences.

In vaccines, polysaccharides linked with carrier proteins are injected into the body. That sets off a process that causes the release of antibodies that recognize the sugars as an unwanted foreign body. The antibodies then remain dormant but ready to attack if they ever see the same polysaccharides again – which would be a signal that bacteria have infected the body.

Polysaccharides are chains of sugars, or monosaccharides, and they are targeted for vaccine development because they are the portion of bacterial cells that interact with the rest of the body.

Escherichia coli was used as a model for the study. Wang and colleagues used one of the existing monosaccharides present on the E. coli cell surface polysaccharides, called fucose, to generate this new modification. They manipulated the structure of the fucose to create 10 different analogs, or forms of the sugar in which just one small component is changed.

The scientists then manually introduced these altered forms of fucose to a solution in which bacterial cells were growing, and the bacterial cells absorbed the altered fucose as they would normal forms of the sugar. The presence of these altered forms of fucose then altered the properties of the polysaccharides that grew on the surface of the cells.

“This way, we don’t have to do anything to modify the polysaccharides. We let bacteria do it for us,” Wang said.

“Bacteria grow lots of polysaccharides – it’s similar to the way humans grow hair. But for a vaccine, you need to make the molecules more active, or energetic,” he said. “In our method, we feed the bacteria these chemicals while they are growing, and those chemicals end up in the polysaccharides and that makes them more immunogenic. That’s the technology.”

Wang said the approach is likely to be applicable to many different kinds of bacteria. But each type of pathogen must be tested individually with the alteration of sugars unique to its surface.

“If you want to prevent one type of bacteria, you have to find something very unique for this bacteria because different microbes have different characteristics,” he said. “You have to find the oddest thing on the cell surface. It has to be on surface because what the body sees first is the surface.”

His lab will next be testing the method’s effectiveness on the pneumococcus bacteria under an exploratory $100,000 grant from the Bill & Melinda Gates Foundation. The current vaccine to prevent pneumonia in babies and the elderly combines 23 strains of bacteria, making it complex and expensive to produce. Each injection costs about $50 in the United States. A less expensive way to develop the vaccine would increase its availability in the developing world, Wang said.

This published research was supported by an endowed Ohio Eminent Scholar Professorship on Macromolecular Structure and Function in the Department of Biochemistry at Ohio State.

Co-authors of the work are Wen Yi, a recipient of a Ph.D. from the Ohio State Biochemistry Program who is now at the California Institute of Technology; Xi Chen of the University of California, Davis; Jianjun Li of the Institute for Biological Sciences at National Research Council of Canada; Chengfeng Xia, Guangyan Zhou and Wenpeng Zhang of Ohio State’s Departments of Biochemistry and Chemistry; Yanhong Li of the University of California, Davis; Xianwei Liu of Shandong University, China; and Wei Zhao of Nankai University, China.

Stem Cells And ABC Transporters Essential In Kidney Regeneration

In a study funded by the Dutch Kidney Foundation (DKF) a research group at Radboud University Nijmegen Medical Centre in the Netherlands, found that stem cells and ABC transporter proteins are indispensable for tubular regeneration after acute kidney injury.Said project leader Dr. Rosalinde Masereeuw: 'To our surprise, our knockout mice for the ABC transporters P-gp and BCRP, P-gycoprotein and breast cancer resistance protein, were protected against acute kidney damage. This was the opposite of what we expected since the transporters usually have a protective function in excreting potentially toxic compounds, while these mice lack expression. Moreover, when we cross transplanted bone marrow between normal mice and the knockouts it turned out that bone marrow from the knockouts was the source of protection.'

Regeneration

Acute kidney injury is an important cause for the need of acute hemodialysis and a source of kidney failure. On the other hand, the kidney has a remarkable capacity for recovery. Stem cells seemed to have a limited share in the repair process, but now this study suggests otherwise.

'It was known that stem cells from the bone marrow express P-gp and BCRP abundantly but will downregulate them at differentiation. Repair of tubular damage in the kidney depends primarily on local cells but stem cells are involved as well. Further, we observed an upregulation in the expression of the transporters during ischemic injury. .So we thought they might be important in renal regeneration.'

Transporter Proteins

ABC transporters (ATP binding cassette transporters) form a superfamily of highly conserved transporter proteins whose functions are not yet well understood. However, BCRP and especially P-gp have been studied in more detail in man. These cell membrane pumps are responsible for the transport of many substances, for instance drug molecules in the intestine. P-gp plays an important role in drug resistance of tumour cells.

Masereeuw: 'Our new hypothesis claims a bigger role for bone marrow derived stem cells in kidney regeneration. A possible mechanism is the infiltration of macrophages. These large immune cells have subgroups one of which increases damage but another supports tissue regeneration.'

Also, the study showed that mice without P-gp expression lose renal tubular function in a way comparable to Fanconi syndrome in man. BCRP knockouts, on the other hand, have a normal kidney function.

Blocking P-gp and BCRP

There is a great need for novel therapies that limit kidney damage after acute injury by toxic substances or shortage of oxygen, as in transplant kidneys which have no blood supply during transport. The results from this DKF study are pointing at inhibition of the transporters in kidney or bone marrow to strengthen the regenerative power of stem cells.

'Next, we will try to discover the mechanism by which stem cells and ABC transporters contribute to kidney repair', concludes Dr. Masereeuw, 'and we will test the effect of transporter blockers in our mouse models. We are convinced there are good opportunities here for new drug targets.'

Pollution-related Asthma May Start In The Womb

Children born in areas with increased traffic-related pollution may be at greater risk of developing asthma due to genetic changes acquired in the womb, according to new research from the University of Cincinnati (UC) and Columbia University Mailman School of Public Health.
In a study of umbilical cord blood from New York City children, researchers have discovered evidence of a possible new biomarker—an epigenetic alteration in the gene ACSL3—associated with prenatal exposure to polycyclic aromatic hydrocarbons (PAHs). These chemical compounds are created as byproducts of incomplete combustion from carbon-containing fuels, resulting in high levels in heavy-traffic areas. Exposure to PAHs has been linked to diseases such as cancer and childhood asthma.

Researchers say this finding provides a potential clue for predicting environmentally related asthma in children—particularly those born to mothers who live in high-traffic areas like Northern Manhattan and South Bronx when pregnant.

This is the first study to examine the effects of prenatal ambient air pollutant exposure on epigenetic changes linked to asthma. Epigenetic changes may disrupt the normal functioning of genes by affecting their expression but do not cause structural changes or mutations in the genes.

The team reports its findings in the Feb. 16, 2009, issue of PLoS One.

For this study, UC researchers teamed with Columbia's Mailman School of Public Health to study the relationship between prenatal PAH exposure and childhood asthma, hypothesizing that transplacental exposure to PAHs could "reprogram" fetal genes and lead to airway inflammation or asthma during childhood. Epigenetic reprogramming is the result of an organism's genes interacting with the environment.

"Our data support the concept that environmental exposures can interact with genes during key developmental periods to trigger disease onset later in life, and that tissues are being reprogrammed to become abnormal later," says Shuk-mei Ho, PhD, senior author of the paper, chair of UC's Department of Environmental Health and the director of the Center for Environmental Genetics.

"This research is aimed at detecting early signs of asthma risk so that we can better prevent this chronic disease that affects as many as 25 percent of children in Northern Manhattan and elsewhere," adds Frederica Perera, DrPH, professor of environmental health sciences and director of the Columbia Center for Children's Environmental Health (CCCEH) at the Mailman School of Public Health and co- first author on the paper.

Using biological specimens from the CCCEH birth cohort of mothers and children living in Northern Manhattan and the South Bronx, UC scientists analyzed umbilical cord white blood cell samples from 56 children for epigenetic alterations related to prenatal PAH exposure. (The mothers' exposure to PAHs was monitored during pregnancy using backpack air monitors).

The researchers found a significant association between changes in ACSL3 methylation—a gene expressed in the lung—and maternal PAH exposure. ACSL3 also was associated with a parental report of asthma symptoms in the children prior to age 5.

With confirmation in further studies, researchers say changes in the ACSL3 gene could serve as a novel biomarker for early diagnosis of pollution-related asthma.

"This study provides a blueprint for the discovery of epigenetic biomarkers relevant to other investigations of exposure-disease relationships in birth cohorts," says Wan-yee Tang, PhD, a UC research scientist and a co-first author on the paper.

"Understanding early predictors of asthma is an important area of investigation," adds Rachel Miller, MD, director of the CCCEH asthma project and study co-author, "because they represent potential clinical targets for intervention."

The CCCEH birth cohort was launched in 1998 to study the effects of prenatal exposure to common urban pollutants on the health of mothers and their children. Children in the cohort were born to non-smoking Dominican and African-American women in Northern Manhattan or the South Bronx and follow-up is ongoing.

Funding for the multi-institutional study comes from the National Institute of Environmental Health Sciences (NIEHS), the U.S. Environmental Protection Agency (EPA) and private foundations. UC's Linda Levin, PhD and Columbia University Mailman School's Julie Herbstman, PhD, and Deliang Tang, MD, DrPH, were also co-authors of the study.

In Flurry Of Studies, Researcher Details Role Of Apples In Inhibiting Breast Cancer

Six studies published in the past year by a Cornell researcher add to growing evidence that an apple a day -- as well as daily helpings of other fruits and vegetables -- can help keep the breast-cancer doctor away.In one of his recent papers, published in the Journal of Agricultural and Food Chemistry (57:1), Rui Hai Liu, Cornell associate professor of food science and a member of Cornell's Institute for Comparative and Environmental Toxicology, reports that fresh apple extracts significantly inhibited the size of mammary tumors in rats -- and the more extracts they were given, the greater the inhibition.

"We not only observed that the treated animals had fewer tumors, but the tumors were smaller, less malignant and grew more slowly compared with the tumors in the untreated rats," said Liu, pointing out that the study confirmed the findings of his preliminary study in rats published in 2007.

In his latest study, for example, he found that a type of adenocarcinoma -- a highly malignant tumor and the main cause of death of breast-cancer patients, as well as of animals with mammary cancer -- was evident in 81 percent of tumors in the control animals. However, it developed in only 57 percent, 50 percent and 23 percent of the rats fed low, middle and high doses of apple extracts (the equivalent of one, three and six apples a day in humans), respectively, during the 24-week study.

"That reflects potent anti-proliferative [rapid decrease] activity," said Liu.

The studies highlight the important role of phytochemicals, known as phenolics or flavonoids, found in apples and other fruits and vegetables. Of the top 25 fruits consumed in the United States, Liu reported in the same journal (56:18) that apples provide 33 percent of the phenolics that Americans consume annually.

In a study of apple peel published in the same journal (56:21), Liu reported on a variety of new phenolic compounds that he discovered that also have "potent antioxidant and anti-proliferative activities" on tumors. And in yet another study in the same journal (56:24), he reported on his discovery of the specific modulation effects that apple extracts have on cell cycle machinery. Recently, Liu's group also reported the finding that apple phytochemicals inhibit an important inflammation pathway (NFkB) in human breast cancer cells.

Breast cancer is the most frequently diagnosed invasive cancer and the second leading cause of cancer deaths in women in the United States, said Liu.

"These studies add to the growing evidence that increased consumption of fruits and vegetables, including apples, would provide consumers with more phenolics, which are proving to have important health benefits. I would encourage consumers to eat more and a wide variety of fruits and vegetables daily."

The studies were supported, in part, by the American Institute for Cancer Research, the Ngan Foundation and the U.S. Apple Association.

Mediterranean Diet Associated With Lower Risk Of Cognitive Impairment

Eating a Mediterranean diet appears to be associated with less risk of mild cognitive impairment—a stage between normal aging and dementia—or of transitioning from mild cognitive impairment into Alzheimer's disease, according to a report in the February issue of Archives of Neurology, one of the JAMA/Archives journals."Among behavioral traits, diet may play an important role in the cause and prevention of Alzheimer's disease," the authors write as background information in the article. Previous studies have shown a lower risk for Alzheimer's disease among those who eat a Mediterranean diet, characterized by high intakes of fish, vegetables, legumes, fruits, cereals and unsaturated fatty acids, low intakes of dairy products, meat and saturated fats and moderate alcohol consumption.

Nikolaos Scarmeas, M.D., and colleagues at Columbia University Medical Center, New York, calculated a score for adherence to the Mediterranean diet among 1,393 individuals with no cognitive problems and 482 patients with mild cognitive impairment. Participants were originally examined, interviewed, screened for cognitive impairments and asked to complete a food frequency questionnaire between 1992 and 1999.

Over an average of 4.5 years of follow-up, 275 of the 1,393 who did not have mild cognitive impairment developed the condition. Compared with the one-third who had the lowest scores for Mediterranean diet adherence, the one-third with the highest scores for Mediterranean diet adherence had a 28 percent lower risk of developing mild cognitive impairment and the one-third in the middle group for Mediterranean diet adherence had a 17 percent lower risk.

Among the 482 with mild cognitive impairment at the beginning of the study, 106 developed Alzheimer's disease over an average 4.3 years of follow-up. Adhering to the Mediterranean diet also was associated with a lower risk for this transition. The one-third of participants with the highest scores for Mediterranean diet adherence had 48 percent less risk and those in the middle one-third of Mediterranean diet adherence had 45 percent less risk than the one-third with the lowest scores.

The Mediterranean diet may improve cholesterol levels, blood sugar levels and blood vessel health overall, or reduce inflammation, all of which have been associated with mild cognitive impairment. Individual food components of the diet also may have an influence on cognitive risk. "For example, potentially beneficial effects for mild cognitive impairment or mild cognitive impairment conversion to Alzheimer's disease have been reported for alcohol, fish, polyunsaturated fatty acids (also for age-related cognitive decline) and lower levels of saturated fatty acids," they write.

Additional studies are needed to confirm the role of this or other dietary factors in the development of cognitive impairment and Alzheimer's disease, they conclude.

This work was supported by grants from the National Institute on Aging.

Genetic Change Prevents Cell Death In Mouse Model Of Parkinson's Disease

By shifting a normal protective mechanism into overdrive, a University of Wisconsin-Madison scientist has completely shielded mice from a toxic chemical that would otherwise cause Parkinson's disease.Parkinson's disease is a disabling and sometimes fatal disease that afflicts 1.5 million Americans, with about 60,000 new cases annually. Its major symptoms, including tremors and sluggish movement, have been traced to death of small numbers of nerve cells in the substantia nigra, a brain region that helps regulate movement.

Adding extra copies of a gene that makes a normal, protective protein neutralized a toxic chemical that would normally devastate the substantia nigra. "This complete abolition of toxicity was far greater than we expected," says Jeffrey Johnson, a UW-Madison professor of pharmacy. "It was striking. We thought we would see a 20 or 30 or 40 percent reduction in cell death."

The protective mechanism is initiated by a protein called Nrf-2, which is present in people and in mice, says Johnson. Nrf-2 (transcription factor NF-E2-related factor) is made by astrocytes, brain cells that play a supportive role to the neurons, which are the cells that actually carry nerve signals.

In recent years, researchers looking at a range of neurodegenerative diseases, including Alzheimer's and Lou Gehrig's diseases as well as Parkinson's, have focused on the astrocytes in their quest to help the brain protect itself from stressful conditions that are deadly to neurons. "Astrocytes way outnumber neurons and are found throughout the central nervous system," says Johnson. "Neurons have always gotten the Academy Awards, but astrocyte dysfunction is becoming a central theme in neurodegenerative disease. If we can figure out how to fix a sick astrocyte, or even prevent it from getting sick, that could offer profound protection against almost all neurodegenerative diseases."

Because neurons are impossible to replace, the present research focus in neurodegenerative disease is on preventing their death in the first place. Parkinson's disease can be treated for a time by replacing dopamine, the brain chemical made by the substantia nigra, but the treatment loses its efficacy over time.

In a study funded by the National Institute of Environmental Health Sciences and published in today's Proceedings of the National Academy of Sciences, Johnson and UW-Madison colleagues Pei-Chun Chen, Marcelo Vargas and Delinda Johnson studied mice with extra Nrf-2 genes. The astrocytes in these mice produced about twice the normal level of Nrf-2 protein.

The researchers then dosed the mice with MPTP, a chemical that kills neurons in the substantia nigra and has become the major mechanism for studying Parkinson's disease in mice. The toxicity of MPTP was discovered in 1982, when young drug users in California developed the classic symptoms of Parkinson's disease, a disease that usually strikes those over age 60. Researchers found that the synthetic heroin these people had used was contaminated with MPTP, and further studies showed that MPTP is highly toxic to nerve cells in the substantia nigra.

When astrocytes make Nrf-2, the protein attaches to their DNA, kick-starting activity in hundreds of genes that release chemicals that can protect nearby neurons from oxidation – a series of chemical reactions that can injure or kill cells. "The astrocytes are also probably sucking up the bad stuff, thereby reducing the oxidative environment and stress on the neurons," says Johnson, adding that his laboratory is trying to identify those specific protective chemicals.

Nobody can predict when a manipulation of Nrf-2 could reach clinical trials, which Johnson says are at the very least two years in the future. While these experiments altered the mouse cells with genetic engineering, human trials would probably use drugs to boost Nrf-2 production in astrocytes. Several labs, including Johnson's, are already searching for candidate drugs.

The stakes are high, Johnson says, because Nrf-2 also protects brain cells in models of such fatal brain diseases as Alzheimer's, ALS, and Huntington's disease.

Normally, neurons die in these neurodegenerative diseases to "commit suicide" through a process called programmed cell death. "Nrf-2 seems to rebalance the system," Johnson says, "in favor of what we call programmed cell life."

Molecule That Suppresses Immune Response Under Study In Type 1 Diabetes

he idea is to teach the immune system of children at high risk for type 1 diabetes not to attack the insulin-producing cells of the pancreas."We want to create a no-go zone," said Dr. Andrew Mellor, immunologist who directs the Medical College of Georgia Immunotherapy Center. Type 1 diabetes is classified as an autoimmune disease because the immune system targets healthy islet cells for destruction, leaving young patients unable to use glucose, a major fuel source for the body.

MCG researchers think they may be able to delay or even prevent that destruction by boosting the body's levels of an enzyme fetuses uses to escape the mother's immune response or by packaging islet cell antigens, which get the immune system's attention, with this suppressor. T-cells are immune cells that decide whether to attack or ignore an antigen. Dr. Mellor believes they'll ignore insulin-producing cells if they see them for the first time with indoleomine 2,3-dioxegenase, or IDO, a powerful immune system inhibitor.

"We are going to be in a situation, in the not too distant future where you can identify an individual at risk, such as a 5-year-old child who has a 90 percent chance of becoming a type 1 diabetic within 10 years," he said. "Once you know that information the onus is on medicine to do something about reducing that risk."

A three-year, $646,000 grant from the Juvenile Diabetes Research Foundation International will enable studies in a classic model of type 1 diabetes: a normal-weight mouse that develops diabetes. Eighty percent of the female mice get diabetes by age 12 to 15 weeks. MCG researchers suspect it's because they have a transient defect in their dendritic cells that hurts IDO expression. Dendritic cells, which can express IDO, show antigens to the T-cells.

A Journal of Immunology paper last year reported that when dendritic cells and IDO are depleted in the mouse, the disease gets worse. Dr. Mellor's research partner Dr. David Munn collaborated with Dr. Jonathan Katz, who directs the Diabetes Research Center at the Cincinnati Children's Hospital Medical Center, on the study. "That was formal evidence that the dendritic cells with IDO were putting the brakes on the disease," said Dr. Mellor, Georgia Research Alliance Eminent Scholar in Molecular Immunogenetics. "It leads to the hypothesis that by reinforcing the IDO mechanism in these mice, you can slow or even prevent the disease." He'll further explore IDO's role in type 1 diabetes by using several different methods to get rid of IDO and observe what happens. He'll also enhance IDO expression in the females by giving a drug commonly used to treat rheumatoid arthritis that the MCG team has learned can boost IDO expression. "The mouse has an endogenous mechanism; it's just defective," said Dr. Mellor. "If you have the IDO come on earlier and stronger, maybe you can slow or halt disease progression or maybe even prevent it."

They'll also deliver a two-step treatment: prompting inflammation, which causes dendritic cells to express IDO, at the same time they give antigens to the insulin-producing cells. "The presence of the antigen excites the T cells if you will, but the presence of IDO tells it to stop getting excited," said Dr. Mellor. The approach has its risks. "The opposite would be disastrous: you would accelerate the disease," said Dr. Mellor. However novel strategies are needed, not just to treat the disease, but to try to prevent it, he said.

Dr. Jin-Xiong She, director of the MCG Center for Biotechnology and Genomic Medicine and Georgia Research Alliance Eminent Scholar in Genomic Medicine, is leading efforts to identify these children. He's a principal investigator on an international effort looking at thousands of babies with genes that put them at high risk for diabetes then following them for years to see how genetics and environment work together to cause the disease. His laboratory studies include identifying additional high-risk genes as well as biomarkers for children at risk.

A different kind of vaccine – one that teaches the immune system to avoid something rather than attack it – may be the best option for these high-risk children, Dr. Mellor said. So he's also using disabled viral vectors, which are good at infecting cells, to deliver IDO as an off switch for the immune system. "We've been thinking IDO for a long time on this one," said Dr. Mellor.

A team of MCG scientists led by Drs. Mellor and Munn showed in research published in Science in 1998 that the fetus expresses IDO to help avoid rejection by the mother’s immune system. They also are exploring its therapeutic potential in transplantation and cancer.

Cancer Diagnosis: Now In 3-D

University of Washington researchers have helped develop a new kind of microscope to visualize cells in three dimensions, an advance that could bring great progress in the field of early cancer detection. The technique could also bridge a widening gap between cutting-edge imaging techniques used in research and clinical practices, researchers said.

Eric Seibel, a UW mechanical engineering associate professor, and his colleagues have worked in collaboration with VisionGate, Inc., a privately held company in Gig Harbor, Wash., that holds the patents on the technology. The machine works by rotating the cell under the microscope lens and taking hundreds of pictures per rotation, and then digitally combining them to form a single 3-D image.

The 3-D visualizations could lead to big advances in early cancer detection, since clinicians today identify cancerous cells by using 2-D pictures to assess the cells' shape and size.

"It's a lot easier to spot a misshapen cell if you can see it from all sides," Seibel said. "A 2-D representation of a 3-D object is never perfectly accurate -- imagine trying to get an exact picture of the moon, seeing only one side."

The new microscope, known by the trademarked name Cell-CT, is so named because it works similarly to a CT-scan -- though on a very small scale, and using visible light instead of X-rays. In a CT-scan, the patient is immobile while the X-ray machine rotates. In the Cell-CT microscope, each cell is embedded in a special gel inside a glass tube that rotates in front of a fixed camera that takes many pictures per rotation. The gel has similar optical properties to the tube's so that no light reflects off the glass. In both processes, the end result is that hundreds of pictures are assembled to form a 3-D image that can be viewed and rotated on a computer screen.

The new 3-D microscope also helps to bring imaging techniques from the lab to the doctor's office. Although great advances have been made in microscope technology through the years, clinicians have been using essentially the same technique for cancer diagnoses for the last 300 years, Seibel said. Pathologists today still use a cell stain invented in the 1700s to examine sections of suspected cancers. Pathologists do not use any of the newer fluorescent molecular dyes that produce the precise, detailed cellular portraits found in biology journals.

"Scientists have been using fluorescent dyes in research for decades, but these techniques have not yet broken into everyday clinical diagnoses," Seibel said. "There's a big gap between the research and clinical worlds when it comes to cancer, and it's getting wider. We're trying to bridge that gap."

Part of the reason for this gap, Seibel said, is that there is no way to accurately match an image taken using the fluorescent dyes with an image taken using the traditional stains that currently form the basis for cancer diagnoses, and for which diagnostic standards exist. The new 3-D microscope will allow that matchup -- Seibel and his colleagues have shown simultaneous fluorescent and traditional staining of the same cells. The new device is the first 3-D microscope that can use both traditional and fluorescent stains, Seibel said.

"Now that we have a way to compare these stains, we hope this will provide a way to get some of those sophisticated research techniques into clinical use," Seibel said.

The new microscope is also more precise than other 3-D machines currently available. All other microscopes producing 3-D images have poor resolution in the up-down direction, the direction between the sample and the microscope's lens, Seibel said.

Qin Miao, a UW bioengineering doctoral student, used a tiny plastic particle of known dimensions to show the microscope's resolution. He found that the UW group's machine has three times better accuracy in that up-down direction than standard microscopes used in cancer detection. Miao will present the group's findings for the microscope's performance Feb. 9 at the SPIE Medical Imaging conference in Orlando, Fla.

"This means we can do quantitative analysis of cells," Miao said. "This kind of undistorted image is difficult to achieve using other technology."

In another recent publication, Seibel and his colleagues describe a study comparing cancer detection using traditional methods with their 3-D microscope. Pathologists using 3-D technology detected cancer with one-third the error rate compared to those using the traditional microscope. The authors also describe using their microscope to discover a "pre-cancer" cell, a cell that was on the verge of turning cancerous.

"This is where we can make an impact in medicine -- looking for these earliest changes," Seibel said.

Other authors of the paper are J. Richard Rahn, Ryland Bryant, Christy Lancaster, Anna Tourovskaia, Dr. Thomas Neumann and Alan Nelson, all of VisionGate.

Funding was provided by VisionGate and the Washington Technology Center.

Cancerous Kidney Removed Through Belly Button

On Thursday, February 5, 2009, surgeons at the University of California, San Diego Medical Center removed a patient’s diseased kidney through one incision hidden in the belly button. No other incisions were used. This groundbreaking procedure is the 15th in a series of single-incision clinical trial surgeries performed by the UC San Diego Center for the Future of Surgery.“The successful removal of a kidney containing a seven centimeter tumor, with a single incision, is a pivotal advancement in cancer care,” said Ithaar H. Derweesh, MD, associate professor of surgery for the Division of Urology and urologic oncologist at UC San Diego Medical Center and Moores UCSD Cancer Center. “This less invasive approach offers patients a shorter recovery time, less need for pain medication, and an improved cosmetic outcome.”

During a traditional laparoscopic surgery, three to five small abdominal incisions would be made to insert a camera and instruments to remove the kidney. This novel surgery required one incision in the navel.

“The idea of being able to perform a surgery with fewer incisions and requiring a shorter hospital stay is particularly attractive to cancer patients who may face repeated surgeries,” said Santiago Horgan, MD, professor of surgery, and Director of the Center for the Future of Surgery at UC San Diego. “We are currently testing these scarless procedures for the treatment of cancer, obesity and other digestive disorders.”

According to the American Cancer Society, kidney cancer is an expanding cancer, increasing at a rate of two to three percent each year and affecting approximately 55,000 patients in the United States. Risk factors for developing kidney cancer include smoking, obesity and hypertension.

“Kidney cancer is among the 10 most common cancers in men and women,” said Derweesh, an expert in kidney-preserving surgeries and a member of the American Urological Association’s Guideline Committee for the treatment of kidney tumors. “The combination of kidney cancers being diagnosed at earlier stages and smaller sizes, and the ability perform less invasive surgeries, presents a new horizon of care for these patients.”

New Cancer Research Tool: Tool Analyzes Function Of Crucial Set Of Proteins In Animals

University of Saskatchewan scientists have developed a new tool that enables scientists to analyze the function of a crucial set of proteins in animals—a finding that could lead to a host of better drugs for and deeper insights into the workings of cancer.

Developed by a team at the Vaccine and Infectious Disease Organization (VIDO), the tool is described in a Jan. 20th article in the prestigious journal Science Signaling. The technology is expected to be rapidly adopted by scientists in a wide range of disciplines and will likely replace the “mouse model” for some types of research.

“This technology is very simple, relatively inexpensive, and can be adopted in any lab,” said project leader Scott Napper. “Scientists can customize it to look at whatever cell function they want to analyze.”

The new tool—called a species-specific peptide array—involves the use of a glass slide with segments of protein molecules affixed to it. It will help scientists analyze kinases, key regulatory molecules in cells. While only a small percentage of human genes code for protein kinases, mutations in many of these genes are at the root of many human diseases.

Kinases have proven so important as drug targets that pharmaceutical companies have directed 50 per cent of their research and development funding to their study. Targeting kinases can completely alter cell function or turn off cell function that’s out of control.

For the past 30 years, scientists have studied mouse models to understand kinase function. But there are problems with this approach.

“It turns out that mice are different enough from humans that a lot of the results in mice don’t translate to humans,” says Napper. “A number of diseases can be effectively treated in mouse models, but that doesn’t mean we’re making headway with humans.”

The team has found that the new tool helps reveal the “kinome” (the protein kinase complement of the human genome) of other animals, such as cows and pigs. These animals have been shown to more accurately replicate the workings of human disease and immunity than mice—but information about the kinome of these animals has long been minimal.

“This will revolutionize our research,” said co-investigator Philip Griebel. “This technology will allow us to test a hypothesis and very quickly validate the results.”

Scientists will now be able to better understand cell communication pathways in humans and animals, he said.

“We can now do a very rapid screening of the kinases, of which there are hundreds in a cell, and quickly identify which are the key regulatory proteins for any one cell function such as cell division or cell death,” said Napper.

While the traditional method for kinome analysis was to analyze the key regulator proteins one at a time, the new technology allows scientists to look at hundreds of these proteins simultaneously. “This gives us a much more complete view of the regulation of overall cell function,” Napper said.

“Knowing how bacteria or viruses evade the immune defenses of host cells will allow us to develop potential therapeutic interventions such as drugs or vaccines,” he said.

While it may one day help illuminate the cellular actions of cancer, the tool has already shed light on Johne’s—a cattle disease possibly linked to Crohn’s disease in humans but whose mechanism has long stumped scientists.

The team, which includes graduate students Shakiba Jalal and Ryan Arsenault, has already received a flurry of emails from scientists interested in the technique. VIDO hopes to offer the new peptide array as a commercially available kit.

The research is funded by Genome Canada, the Beef Cattle Research Council and Alberta Livestock Industry Development Fund.

PET/CT May Improve Prognosis For Patients With Inflammatory Breast Cancer

In the largest study to date to evaluate fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) in the initial staging of inflammatory breast cancer (IBC), researchers were able to identify the precise location and extent of metastasis (spread of disease), offering the potential for a better prognosis for patients with this rare, but aggressive form of breast cancer.

"PET/CT is useful in staging IBC because it provides information on both the primary disease site as well as disease involvement throughout the rest of the body," said Homer A. Macapinlac, MD, chair and professor of nuclear medicine at the University of Texas, M. D. Anderson Cancer Center, Houston, Texas. "In addition to detecting the presence of cancer, PET/CT is able to demonstrate the biology of cancer—revealing how aggressive the disease is—which can help physicians develop appropriate therapy approaches."

For the study, published in the February issue of The Journal of Nuclear Medicine, researchers reported findings in 41 women between the ages of 25 and 71 with unilateral primary IBC who had originally presented with swelling, some pain and skin changes, such as rash and skin discoloration. A palpable mass was not evident on physical examination in 26 patients (63 percent), which is not unusual in this form of breast cancer, and 90 percent had no symptoms of distant metastasis (disease spread beyond the breast).

Each patient underwent a whole-body FDG-PET/CT exam. The scans showed that nearly half of the patients (49 percent) had distant metastasis, and 27 percent had disease in multiple sites. Neither finding had been previously detected by conventional imaging. These results were confirmed by biopsy and supplementary imaging.

"Breast cancer is a systemic disease, not just a local one. Most imaging modalities are localized and will therefore miss the spread of disease that is frequently present by the time IBC is diagnosed," Macapinlac said. "The use of a whole-body modality such as PET/CT with its higher sensitivity, however, allows us to pinpoint metastasis in other parts of the body; for example, behind the clavicle—which can not be detected in a physical exam—or in the abdominal organs or pelvic lymph nodes."

IBC tends to grow more quickly and aggressively than the more common types of breast cancer. Upon diagnosis, it is already considered to be at least stage IIIB (locally advanced) and even stage IV if it has spread to distant parts of the body. Because of this, IBC has been harder to successfully treat than other types of breast cancer. Knowing the extent of the disease at the start could have a great impact on the outcome for many patients, Macapinlac added.

"With FDG-PET/CT, physicians are able to accurately determine the location of metastases early in the disease process when appropriate treatment can be administered. Furthermore, a PET/CT procedure for IBC patients may be less than or equivalent to the total cost of separately imaging multiple organs and would require a single hospital visit and decreased imaging time when compared to the time required for a battery of regional staging studies," Macapinlac said.

The researchers would like to see future studies that use PET/CT earlier in the process and also to track therapy response to determine whether or not it is succeeding.

"Knowing the extent of disease up front has great implication for prognosis," Macapinlac said. "IBC is a treatable disease. The sooner we can determine the extent, the sooner we can begin aggressive therapy."

PET provides information about how the body is functioning at the cellular level, while CT provides an anatomical rendering of the inside of the body. In an FDG-PET/CT scan, the CT first produces detailed images of the inner anatomy of the body. The patient is then injected with a small amount of a radioactive drug, which is F-18-labeled glucose, and PET is performed. Because fast-growing cancer cells feed on sugars such as glucose, PET/CT delineates areas where the glucose accumulates in the body, identifying the location of cancer cells.

According to the American Cancer Society, IBC accounts for approximately 1 to 3 percent of all breast cancers diagnosed in the United States. It tends to occur in younger women, and African-Americans appear to be at higher risk. Physicians call the disease "inflammatory breast cancer" because the affected breast displays the same symptoms that occur with inflammation. However, the symptoms of IBC are not caused by infection or injury, but by cancer cells blocking lymph vessels in the skin. Patients often do not have a breast lump, and symptoms may not show up on a mammogram. Because it doesn't look like a typical breast cancer, the disease can be harder to diagnose.

New Technique Developed For Quick Detection Of Salmonella

In the hours following an outbreak of salmonella, there are many questions. And answers can be hard to find. Where did the problem start? Can it be contained? Is the sickness likely to spread?

Iowa State University researchers have developed a technique for testing for the presence of salmonella that may give investigators better, faster answers.

The process, developed by Byron Brehm-Stecher, assistant professor in food science and human nutrition, and his graduate student Bledar Bisha, begins with testing the food, in most cases produce, with a strip of adhesive tape.

The tape is applied to the produce, then carefully removed, taking a sample of whatever is on the skin of the produce. That sample is then put on a slide and soaked in a special warm, soapy mixture that contains a genetic marker that binds with salmonella and gives off a fluorescent glow when viewed under an ultraviolet light. Use of this genetic marker approach is called Fluorescent In-Situ Hybridization, or FISH.

The approach can tell investigators if the produce is contaminated with salmonella in about two hours.

"This method is rapid, it's easy, and it's cheap," said Brehm-Stecher.

Current methods of detecting salmonella take one to seven days.

Brehm-Stecher and Bisha call the process "tape-FISH" and note that it could be an important technique for salmonella investigators.

"I think this will be good tool in outbreak investigation and routine surveillance especially since all you need is tape, a heat block, a small centrifuge and a fluorescence microscope," said Brehm-Stecher. "It has the potential to be very portable."

Brehm-Stecher's and Bisha's findings will be published in the journal Applied and Environmental Microbiology, published by the American Society of Microbiology.

Once at a location where an outbreak of salmonella has occurred, investigators can test the produce for contamination. Outbreaks can be due to other factors such as food preparation.

Once investigators find the origin of the salmonella, they can take steps to contain it, said Brehm-Stecher.

Salmonella can be found on produce such as tomatoes, cilantro, peppers, spinach and others. The produce can be contaminated while it is in the fields or during processing. Washing the produce thoroughly can help, but cannot ensure the produce will be safe.

The tape-FISH technique can also be used to test produce that is not suspected of being contaminated, but the volume of produce that would need to be tested may make this impractical. However, the technique could be very valuable as a basic research tool. Researchers could investigate how salmonella and other types of organisms interact on produce surfaces, said Brehm-Stecher.

This is the first application of tape-FISH to salmonella, but the idea came to the ISU researcher while reading about art restoration.

In 2008, Brehm-Stecher read about an Italian group that was using a similar approach to look for bacteria on ancient catacombs. Those researchers were hoping to identify and remove bacteria that were slowly eating away at the relics.

After some classroom discussion with his students, Brehm-Stecher decided that using the FISH on produce could be useful and began researching the idea with Bisha. Together, they were able to apply the method to produce and made several improvements in speed and sensitivity over the existing tape-FISH approach. Brehm-Stecher hopes that his tape-FISH approach can help speed investigations of produce contamination, such as last summer's outbreak of Salmonella Saintpaul, which was eventually traced to imported jalapeno and Serrano peppers.

Don’t Go Changing: New Chemical Keeps Stem Cells Young

Scientists at the Universities of Bath and Leeds have discovered a chemical that stops stem cells from turning into other cell types, allowing researchers to use these cells to develop new medical treatments more easily.

Stem cells have the ability to develop into many other cell types in the body, and scientists believe they have huge potential to treat diseases or injuries that don’t currently have a cure.

Professor Melanie Welham’s team at the University of Bath’s Department of Pharmacy & Pharmacology, collaborating with Professor Adam Nelson at the University of Leeds, have discovered a chemical that can be added to embryonic stem cells grown in the lab, allowing them to multiply without changing into other cell types.

This breakthrough will help scientists produce large stocks of cells that are needed for developing new medical therapies.

Professor Welham, who is co-director of the University of Bath’s Centre for Regenerative Medicine, explained: “Stem cells have great potential for treating spinal injuries and diseases like type I diabetes because they can change into a range of specialised cell types including nerve or pancreatic cells, which could be used to repair damaged tissues.

“Unfortunately, when you grow stem cells in the lab, they can spontaneously develop into specialised cells, making it difficult to grow large enough stocks to use for medical research.

“We’ve identified a chemical that will put this process on hold for several weeks so that we can grow large numbers of them in their unspecialised state. This is reversible, so when you take it away from the cells, they still have the ability to change into specialised cells.”

Professor Adam Nelson’s team, at the Astbury Centre for Structural Molecular Biology, made more than 50 chemical compounds that were tested for activity in the stem cells.The researchers found that the chemicals worked by blocking an enzyme, called GSK3, that can control when the stem cell switches to a more specialised cell type.

Professor Nelson, who is Director of the Astbury Centre at the University of Leeds, said: “This research is a great example of how small molecules can be used as tools to understand biological mechanisms.”

The research, supported by funding from the Biotechnology & Biological Sciences Research Council.

Gene Mutations Increase Risk For Aggressive Prostate Cancer

Men who develop prostate cancer face an increased risk of having an aggressive tumor if they carry a so-called breast cancer gene mutation, scientists from the Albert Einstein College of Medicine of Yeshiva University report in the January 29 issue of Clinical Cancer Research. The findings could help to guide prostate-cancer patients and their physicians in choosing treatment options.

The study, involving 979 men with prostate cancer and 1251 men without the disease, looked at whether participants carried mutations for either of two genes, BRCA1 and BRCA2. Women carrying mutations in either gene face an increased risk of developing breast cancer, ovarian cancer, or both.

All the people enrolled in the Einstein study were of Ashkenazi Jewish descent. The study focused on them because they are five times likelier than people in the general population to carry a mutation of any kind in the BRCA1 or BRCA2 genes. The researchers looked for the presence of three particular mutations–two in BRCA1 and one in BRCA2. Scientists believe that genetic discoveries among the Ashkenazi can benefit society as a whole in terms of preventing and treating major diseases.

Having any of the three mutations did not increase a man's risk of developing prostate cancer, the study found. But for those men who did develop prostate cancer, two of the mutations–BRCA1-185delAG and the mutated BRCA2 gene–increased the risk that tumors would be aggressive or high-grade, as defined by a Gleason score of 7 or above. The Gleason score, based on the microscopic appearance of prostate tissue removed during a biopsy or surgery, assesses the aggressiveness of a prostate tumor on a scale from 2 (least aggressive) to 10 (most aggressive).

Specifically, prostate cancer patients with high-grade, aggressive tumors (Gleason scores of 7 or above) were 3.2 times more likely to carry the BRCA2 gene mutation than were men in the control group. Carriers of the BRCA1-185delAG mutation were also at increased risk of having an aggressive prostate cancer.

Previous investigations into a possible link between prostate-cancer risk and the BRCA1 and BRCA2 genes have yielded conflicting results–perhaps because they involved small numbers of subjects and lacked well-matched control groups. "Our large study shows conclusively that prostate cancer patients with either the BRCA2 gene mutation or the BRCA1-185delAG mutation are more susceptible to aggressive cancers than people without that mutation," says Robert Burk, M.D., professor of pediatrics (genetics) at Einstein and senior author of the study.

Routine genetic testing for BRCA mutations–done by analyzing blood samples or cells swabbed from the inside of one's cheeks–wouldn't be justified for most men, says Dr. Burk: the prevalence of the mutations in the general population is very low; and men with high Gleason scores already know that their prostate cancer is aggressive. But, notes Dr. Burk, "our findings might have practical implications for some men diagnosed with early-stage (low Gleason score) prostate cancers–particularly Ashkenazi Jewish men, who are much more likely to have these mutations."

"One of the biggest problems with early-stage prostate cancer is being able to distinguish between tumors with the potential to become aggressive and those that may persist for many years without enlarging or spreading," notes Dr. Burk. For that reason, he says, Ashkenazi men diagnosed with early-stage prostate cancer might want to consider getting tested for the BRCA2 and BRCA1-185delAG mutations.

Knowing they have the mutation—and that their tumor may become aggressive—may influence treatment options that patients pursue. For example, a prostate cancer patient who has the BRCA2 mutation might vote against 'watchful waiting'—in which the growth of the cancer is monitored and treatment is held in abeyance—and instead opt for surgery or radiation treatments with or without hormone blockade therapy.

For early-stage prostate cancer patients in the general population, knowing they carry the BRCA1 or BRCA2 mutation would also be useful, says Dr. Burk. But these mutations are so rare in the general population—a prevalence of far less than one percent—that testing is unlikely to reveal their presence.

Other Einstein researchers involved in the study were Dr. Ilir Agalliu and Suzanne Leanza. The authors have no potential conflicts of interest relevant to this article.

Mesh-like Network Of Arteries Adjusts To Restore Blood Flow To Stroke-injured Brain

A grid of small arteries at the surface of the brain redirects flow and widens at critical points to restore blood supply to tissue starved of nutrients and oxygen following a stroke, a new study has found.

“This is optimistic news,” said David Kleinfeld, a physics professor at the University of California, San Diego, whose group studies blood flow in animal models of stroke.

Damage from stroke can continue for hours or even days as compromised brain tissue surrounding the core injury succumbs to deprivation of oxygen and nutrients.

“This is the area doctors are trying to protect after a stroke,” said Andy Shih, a postdoctoral fellow in Kleinfeld’s group who conducted the experiments. “Those neurons are teetering on the edge of death and survival.”

Previous work with animal models had found that blood flow can persistently slow in the aftermath of a stroke, which would hinder the delivery of drugs that might help recovery. But those studies only measured the speed of the blood.

By measuring both the speed of blood cells moving through individual small arteries and the diameters of the same vessels, the scientists found that the arteries dilate to maintain a constant delivery of blood cells.

“You find that the velocity has gone down, but that the diameter—on average—exactly compensates,” Kleinfeld said.

Patrick Drew and Philbert Tsai in Kleinfeld’s group, and Beth Friedman and Patrick Lyden, MD, of the neuroscience department at UC San Diego’s School of Medicine co-authored the paper. Lyden, whose contributions to a 1995 study proved that the drug tPA can reverse the course of stroke when administered promptly, also directs the UC San Diego Stroke Center. The Journal of Cerebral Blood Flow and Metabolism published their new finding online January 28.

Key to this resilience, it seems, is the structure of the vascular network overlying the brain.

“Vessels on the surface of the brain have a mesh-like architecture,” Kleinfeld said. “One consequence of that is that it operates like a grid system that redistributes “current flow as you need it.”

“City traffic freezes a lot less than you would think because once a street gets bogged down, you can move over to another street,” he said. “This seems to be what happens on the surface of the brain.”

Flows through the surface vessels reversed and stalled, as previously observed, but those changes helped to redistribute blood to ensure a steady supply though vessels that penetrate into the brain.

Shih focused his measurements on small arteries, called arterioles, at the point where they dive into the brain to supply a discrete patch of the cortex, a juncture that is vulnerable to occlusions that can cause microstrokes this group’s previous work has found.

“These are extremely important. A single penetrating arteriole will feed a column of tissue,” Shih said. “These are bottlenecks in flow.”

The penetrating vessels neither reversed nor stalled, even though many connected to loops and bridges in the vascular network that could have allowed that to happen. Even when the pressure dropped permanently as a result of stroke damage, wider lanes allowed the network to deliver red blood cells at the same rate.

“Diameter is the major determinant to how blood actually flows through vessels. Open up a blood vessel a little bit and you’ll have a huge change in the amount of blood that goes through,” Shih said. “Blood flow comes back, and it seems that these vessels are very resistant to the stroke. They function quite normally.”

The work was funded by the Canadian Institutes of Health Research, National Institutes of Health, National Science Foundation and Veterans Medical Research Foundation.

Alzheimer's Prevented And Reversed With Natural Protein In Animal Models

Memory loss, cognitive impairment, brain cell degeneration and cell death were prevented or reversed in several animal models after treatment with a naturally occurring protein called brain-derived neurotrophic factor (BDNF). The study by a University of California, San Diego-led team – published in the February 8, 2009 issue of Nature Medicine – shows that BDNF treatment can potentially provide long-lasting protection by slowing, or even stopping the progression of Alzheimer's disease in animal models.

"The effects of BDNF were potent," said Mark Tuszynski, MD, PhD, professor of neurosciences at the UC San Diego School of Medicine and neurologist at the Veterans Affairs San Diego Health System. "When we administered BDNF to memory circuits in the brain, we directly stimulated their activity and prevented cell death from the underlying disease."

BDNF is normally produced throughout life in the entorhinal cortex, a portion of the brain that supports memory. Its production decreases in the presence of Alzheimer's disease. For these experiments, the researchers injected the BDNF gene or protein in a series of cell culture and animal models, including transgenic mouse models of Alzheimer's disease; aged rats; rats with induced damage to the entorhinal cortex; aged rhesus monkeys, and monkeys with entorhinal cortex damage.

In each case, when compared with control groups not treated with BDNF, the treated animals demonstrated significant improvement in the performance of a variety of learning and memory tests. Notably, the brains of the treated animals also exhibited restored BDNF gene expression, enhanced cell size, improved cell signaling, and activation of function in neurons that would otherwise have degenerated, compared to untreated animals. These benefits extended to the degenerating hippocampus where short-term memory is processed, one of the first regions of the brain to suffer damage in Alzheimer's disease.

The demonstration of the effectiveness and safety of BDNF administration in animals provides "a rationale for exploring clinical translation" to humans, the team concludes, suggesting that the protective and restorative effects of BDNF on damaged neurons and neuronal signaling may offer a new approach to treating Alzheimer's disease.

This work builds on previous studies by Tuszynski and others, demonstrating the therapeutic affects of nerve growth factor (NGF) administered to patients with Alzheimer's disease. In 2001, Tuszynski and his team at UC San Diego Medical Center performed the first surgical implants of NGF genes into the brains of Alzheimer's patients, with follow-up results showing these patients experienced a possible slowing in cognitive decline and increased metabolic function in the brain. The NGF studies continue today, with Phase 2, multi-center studies currently underway.

"NGF therapy aims to stimulate the function of specific cholinergic neurons, which are like the air traffic controllers of the brain, helping to direct the activities of cells in broad regions of the brain," Tuszynski explained. However, he added that the benefits of NGF therapy, if validated in ongoing trials, will not be curative. Eventually, the effect of the NGF "boost" will be countered by the widespread death of neurons in the cerebral cortex as a result of advancing Alzheimer's disease.

"In contrast, BDNF acts directly on dying cells in specific memory circuits of the brain," Tuszynski said. "In this series of studies, we have shown that BDNF targets the cortical cells themselves, preventing their death, stimulating their function, and improving learning and memory. Thus, BDNF treatment can potentially provide long-lasting protection by slowing, or even stopping disease progression in the cortical regions that receive treatment."

The protective and restorative effects of BDNF occurred independently of the build-up of amyloid, a protein that accumulates in the brain to form plaques in Alzheimer's disease. Many current experimental treatments for Alzheimer's disease target amyloid production, so the potential role of BDNF as an alternative protective intervention is of great potential interest, said Tuszynski. Because BDNF targets a different set of disease mechanisms than amyloid modulation, there is also potential to combine BDNF and amyloid-based treatments, theoretically providing a two-pronged attack on the disease.

The study was supported by the National Institutes of Health, the California Regional Primate Research Center, the Veterans Administration, the Alzheimer's Association, the State of California, the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation and the Shiley Family Foundation. Tuszynski is scientific founder of Trophin Therapeutics, a company that may potentially benefit from the research results.

Study co-authors are Alan H. Nagahura, David A. Merrill, Shingo Tsukada, Brock E. Schroeder, Gideon M. Shaked, Ling Want, Armin Blesch, James M. Conner, Edward Rockenstein, Edward H. Koo, and Eliezer Masliah of the UC San Diego Department of Neurosciences, and Andrea A. Chiba of the UC San Diego Departments of Neurosciences and Cognitive Science. Giovanni Coppola and Daniel Geschwind of the Program in Neurogenetics, Department of Neurology at UCLA, and Albert Kim and Moses V. Chao, Skirball Institute of Biomolecular Medicine at New York University School of Medicine.

Scientists Develop 'Crystal Ball' For Personalized Cancer Treatment

For many cancer patients, chemotherapy can be worse than cancer itself. A patient may respond to one drug but not another -- or the tumor may mutate and stop responding to the drug -- resulting in months of wasted time, ineffective treatment and toxic side effects.Now UCLA scientists have tested a non-invasive approach that may one day allow doctors to evaluate a tumor's response to a drug before prescribing therapy, enabling physicians to quickly pinpoint the most effective treatment and personalize it to the patient's unique biochemistry. The Proceedings of the National Academy of Sciences publishes the UCLA findings in its Feb. 2 advance online edition.

"For the first time, we can watch a chemotherapy drug working inside the living body in real time," explained Dr. Caius Radu, a researcher at the Crump Institute for Molecular Imaging and assistant professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA. "We plan to test this method in healthy volunteers within the year to determine whether we can replicate our current results in humans."

In an earlier study, Radu and his colleagues created a small probe by slightly altering the molecular structure of gemcitabine, one of the most commonly used chemotherapy drugs. They labeled the probe with a special tag that enabled them to watch its movement throughout the body during imaging.

In this study, the UCLA team injected the probe into mice that had developed leukemia and lymphoma tumors. After an hour, the researchers imaged the animals' bodies with positron emission tomography (PET), a non-invasive scan often used on cancer patients to identify whether a tumor has spread from its original site or returned after remission.

"The PET scanner operates like a molecular camera, enabling us to watch biological processes in living animals and people," said Radu, who is also a member of the Jonsson Comprehensive Cancer Center at UCLA. "Because we tag the probe with positron-emitting particles, the cells that absorb it glow brighter under the PET scan."

"The PET scan offers a preview for how the tumor will react to a specific therapy," added first author Rachel Laing, a UCLA graduate researcher in molecular and medical pharmacology. "We believe that the tumor cells that absorb the probe will also take up the drug. If the cells do not absorb the probe, it suggests that the tumor might respond better to another medication."

The UCLA researchers plan to expand the scope of their research by examining whether the probe can predict cellular response to several other widely used chemotherapy drugs. Their goal is to determine whether the probe can provide a diagnostic test of clinical value.

"The beauty of this approach is that it is completely non-invasive and without side effects," said Radu. "If we are successful in transporting this test to a clinical setting, patients will be able to go home immediately and resume their daily activities."

If testing in healthy subjects proves safe and effective, UCLA researchers will begin recruiting volunteers for a larger clinical study of the probe in cancer patients.

The study was funded by The Dana Foundation, National Cancer Institute, Department of Energy and Howard Hughes Medical Institute. Radu and Laing's coauthors included Martin Walter, Dean Campbell, Harvey Herschman, Nagichettiar Satyamurthy, Michael Phelps, Johannes Czernin and Owen Witte, all of UCLA.