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Thursday, July 28, 2011

Analysis of Bronchoaveolar Lavage Fluid in Cats


Bronchoalveolar lavage fluid (BALF) collection is an important diagnostic tool for cats with respiratory disease, especially lower respiratory tract disease. The accurate cytological evaluation of BALF is a useful means of differentiating disease processes. The procedure can also be used as a means to monitor the progression of disease or the response to therapy. The effects of storage on BALF values of total nucleated cell counts (TNCC) and differential cell counts (DCC), cell morphology and cytological diagnosis were evaluated. Samples from 45 research cats with neutrophilic, eosinophilic, and mixed inflammation and healthy controls were utilized for the study. The BALF samples were evaluated at 1 hour, or stored at 4 C° or room temperature for 24 hours, or 4 C° or room temperature for 48 hours. Storage of feline BALF at various time and temperature conditions alters TNCC and DCC, cellular morphology, and cytological diagnosis. There was a significant decrease in BALF TNCC in samples stored at room temperature for 48 hours. There was also an increase in the percentage of BALF eosinophils following storage at room temperature for 24 and 48 hours. The authors noted that it is important to remember that the relative increase in percentage of eosinophils is the result in a decrease in other cell lines due to cellular apoptosis accelerated with the storage at room temperature. Following storage, there was a misclassification of the cytological analysis of BALF from inflammatory airway disease to non-inflammatory in 9-18% of the samples. Many BALF samples (31-57%) had a change in cytological diagnosis following storage, similarly rising along with the increase in storage time and temperature. Ideally, analysis of feline BALF should be performed promptly after collection.  [VT]

Related articles:
Nafe L, Declue AE, Lee-Fowler TM, et al. Evaluation of biomarkers in bronchoalveolar lavage fluid for discrimination between asthma and chronic bronchitis in cats. Am J Vet Res 2010;71:583-591.


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Bronchoalveolar lavage fluid (BALF) collection is an important diagnostic tool for cats with respiratory disease, especially lower respiratory tract disease. The accurate cytological evaluation of BALF is a useful means of differentiating disease processes. The procedure can also be used as a means to monitor the progression of disease or the response to therapy. The effects of storage on BALF values of total nucleated cell counts (TNCC) and differential cell counts (DCC), cell morphology and cytological diagnosis were evaluated. Samples from 45 research cats with neutrophilic, eosinophilic, and mixed inflammation and healthy controls were utilized for the study. The BALF samples were evaluated at 1 hour, or stored at 4 C° or room temperature for 24 hours, or 4 C° or room temperature for 48 hours. Storage of feline BALF at various time and temperature conditions alters TNCC and DCC, cellular morphology, and cytological diagnosis. There was a significant decrease in BALF TNCC in samples stored at room temperature for 48 hours. There was also an increase in the percentage of BALF eosinophils following storage at room temperature for 24 and 48 hours. The authors noted that it is important to remember that the relative increase in percentage of eosinophils is the result in a decrease in other cell lines due to cellular apoptosis accelerated with the storage at room temperature. Following storage, there was a misclassification of the cytological analysis of BALF from inflammatory airway disease to non-inflammatory in 9-18% of the samples. Many BALF samples (31-57%) had a change in cytological diagnosis following storage, similarly rising along with the increase in storage time and temperature. Ideally, analysis of feline BALF should be performed promptly after collection.  [VT]

Related articles:
Nafe L, Declue AE, Lee-Fowler TM, et al. Evaluation of biomarkers in bronchoalveolar lavage fluid for discrimination between asthma and chronic bronchitis in cats. Am J Vet Res 2010;71:583-591.


More on cat health: Winn Feline Foundation Library
Join us on Facebook
Follow us on Twitter
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Monday, July 25, 2011

Feline Cytauxzoonosis


Cytauxzoonosis is an acute-onset disease of cats caused by the parasite Cytauxzoon felis, which is transmitted by the bite of a tick. The disease is historically considered a fatal infection in domestic cats, though a number of cats have been known to have survived the disease. Most affected cats are young adults with exposure to the outdoors and vague clinical signs of lethargy and anorexia. The standard therapy for cytauxzoonosis has become imidocarb diproprionate. A combination of atovaquone and azithromycin (A&A) has also been suggested as a treatment.  Neither form of therapy has been prospectively evaluated for efficacy. Eighty acutely ill cats with Cytauxzoon felis infection were treated at one of 18 veterinary clinics.  Of 53 cats treated with A&A, 32 (60%) survived to discharge. Only 7 of 27 cats (26%) treated with imidocarb survived. Still, mortality remained high with approximately 40% of A&A treated cats dying in the hospital. The course of illness is swift and most cats that died did so shortly after presentation for care. The authors suggest that efforts must remain focused on prevention of disease, either through minimization of exposure to tick vectors or through development of chemoprophylaxis or vaccination. [VT]

Related articles:

Cytauxzoonosis is an acute-onset disease of cats caused by the parasite Cytauxzoon felis, which is transmitted by the bite of a tick. The disease is historically considered a fatal infection in domestic cats, though a number of cats have been known to have survived the disease. Most affected cats are young adults with exposure to the outdoors and vague clinical signs of lethargy and anorexia. The standard therapy for cytauxzoonosis has become imidocarb diproprionate. A combination of atovaquone and azithromycin (A&A) has also been suggested as a treatment.  Neither form of therapy has been prospectively evaluated for efficacy. Eighty acutely ill cats with Cytauxzoon felis infection were treated at one of 18 veterinary clinics.  Of 53 cats treated with A&A, 32 (60%) survived to discharge. Only 7 of 27 cats (26%) treated with imidocarb survived. Still, mortality remained high with approximately 40% of A&A treated cats dying in the hospital. The course of illness is swift and most cats that died did so shortly after presentation for care. The authors suggest that efforts must remain focused on prevention of disease, either through minimization of exposure to tick vectors or through development of chemoprophylaxis or vaccination. [VT]

Related articles:
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Sunday, July 24, 2011

The Onion, a Natural Alternative to Artificial Preservatives

Some components of the onion have antioxidant and antimicrobial properties, making it possible to use this bulb for food preservation. This is demonstrated by researchers from the Polytechnic University of Cataluña (UPC) and the University of Barcelona (UB) in a study that has just been published in the International Journal of Food Science and Technology.

"The antioxidant and antimicrobial properties of the flavonoids of the raw onion make it a good candidate for use in food preservation," says researcher Jonathan Santas from the Department of Nutrition and Bromatology at UB and co-author of a project carried out in the Department of Agrifood Engineering and Biotechnology at UPC.

The study, that has just been published by the International Journal of Food Science and Technology, shows that the flavonoids of onion, in addition to having beneficial properties for health, increase the life of foods, and so "they are a natural alternative to artificial additives used in the food industry." Flavonoids are phenolic compounds (with the phenol group) which are synthesized by plants.

The results confirm that, especially the yellow variety, is "a good source of these types of substances, and there is a positive correlation between the presence of flavonoids and their antioxidant capacity."

"The onion can be effective for delaying lipid oxidation in emulsions of oil and water -a model system of foods like margarines and mayonnaises-, and it also inhibits the growth of microorganisms that alter foods," Santas indicates.

The scientific team analysed onions of the White varieties "Fuentes de Ebro" and "Calçot de Valls" and the yellow variety "Grano de Oro." Using them the researchers demonstrated that phenolic compounds in the onion prevent the development of bacteria such as Bacillus cereus, Staphylococcus aureus, Micrococcus luteus and Listeria monocytogenes, microorganisms typically associated with the deterioration of foods.

Previous studies indicate that flavonoids have beneficial effects for health due to their antioxidant, anti-inflammatory, cardioprotective, vasodilatory and anti-carcinogenic properties, making it of special interest in the prevention of chronic illnesses, such as cardiovascular illnesses, and some types of cancer.


A more stable component


The flavonoids of the onion are more stable than some of its other components, such as sulphur compounds. Traditionally it was indicated that these sulphuric compounds are good for the health, as they are responsible for the characteristic taste, aroma and lacrimogenic effects of the plant. These substances, which are very volatile and unstable, are released when the onion is damaged or cut.

The onion (Allium cepa) is one of the most cultivated and consumed vegetables on the planet (around 66 million tonnes in 2008, of which 1.1 million were produced in Spain, especially in Castilla-La Mancha), and one of the main ingredients of the Mediterranean diet.
Some components of the onion have antioxidant and antimicrobial properties, making it possible to use this bulb for food preservation. This is demonstrated by researchers from the Polytechnic University of Cataluña (UPC) and the University of Barcelona (UB) in a study that has just been published in the International Journal of Food Science and Technology.

"The antioxidant and antimicrobial properties of the flavonoids of the raw onion make it a good candidate for use in food preservation," says researcher Jonathan Santas from the Department of Nutrition and Bromatology at UB and co-author of a project carried out in the Department of Agrifood Engineering and Biotechnology at UPC.

The study, that has just been published by the International Journal of Food Science and Technology, shows that the flavonoids of onion, in addition to having beneficial properties for health, increase the life of foods, and so "they are a natural alternative to artificial additives used in the food industry." Flavonoids are phenolic compounds (with the phenol group) which are synthesized by plants.

The results confirm that, especially the yellow variety, is "a good source of these types of substances, and there is a positive correlation between the presence of flavonoids and their antioxidant capacity."

"The onion can be effective for delaying lipid oxidation in emulsions of oil and water -a model system of foods like margarines and mayonnaises-, and it also inhibits the growth of microorganisms that alter foods," Santas indicates.

The scientific team analysed onions of the White varieties "Fuentes de Ebro" and "Calçot de Valls" and the yellow variety "Grano de Oro." Using them the researchers demonstrated that phenolic compounds in the onion prevent the development of bacteria such as Bacillus cereus, Staphylococcus aureus, Micrococcus luteus and Listeria monocytogenes, microorganisms typically associated with the deterioration of foods.

Previous studies indicate that flavonoids have beneficial effects for health due to their antioxidant, anti-inflammatory, cardioprotective, vasodilatory and anti-carcinogenic properties, making it of special interest in the prevention of chronic illnesses, such as cardiovascular illnesses, and some types of cancer.


A more stable component


The flavonoids of the onion are more stable than some of its other components, such as sulphur compounds. Traditionally it was indicated that these sulphuric compounds are good for the health, as they are responsible for the characteristic taste, aroma and lacrimogenic effects of the plant. These substances, which are very volatile and unstable, are released when the onion is damaged or cut.

The onion (Allium cepa) is one of the most cultivated and consumed vegetables on the planet (around 66 million tonnes in 2008, of which 1.1 million were produced in Spain, especially in Castilla-La Mancha), and one of the main ingredients of the Mediterranean diet.
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Effect of dietary krill oil supplementation on the endocannabinoidome of metabolically relevant tissues from high fat-fed mice.

ABSTRACT: BACKGROUND: Omega-3 polyunsaturated fatty acids (omega-3-PUFA) are known to ameliorate several metabolic risk factors for cardiovascular disease, and an association between elevated peripheral levels of endogenous ligands of cannabinoid receptors (endocannabinoids) and the metabolic syndrome has been reported. We investigated the dose-dependent effects of dietary omega-3-PUFA supplementation, given as krill oil (KO), on metabolic parameters in high fat diet (HFD)-fed mice and, in parallel, on the levels, in inguinal and epididymal adipose tissue (AT), liver, gastrocnemius muscle, kidneys and heart, of: 1) the endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), 2) two anandamide congeners which activate PPARalpha but not cannabinoid receptors, N-oleoylethanolamine (OEA) and N-palmitoylethanolamine (PEA), and 3) the direct biosynthetic precursors of these compounds. Methods: Lipids were identified and quantified using liquid chromatography coupled to atmospheric pressure chemical ionization single quadrupole mass spectrometry (LC-APCI- MS) or high resolution ion trap-time of flight mass spectrometry (LC-IT-ToF-MS).

Eight-week HFD increased endocannabinoid levels in all tissues except the liver and epididymal AT, and KO reduced anandamide and/or 2-AG levels in all tissues but not in the liver, usually in a dose-dependent manner. Levels of endocannabinoid precursors were also generally down-regulated, indicating that KO affects levels of endocannabinoids in part by reducing the availability of their biosynthetic precursors. Usually smaller effects were found of KO on OEA and PEA levels. Conclusions: Our data suggest that KO may promote therapeutic benefit by reducing endocannabinoid precursor availability and hence endocannabinoid biosynthesis.
ABSTRACT: BACKGROUND: Omega-3 polyunsaturated fatty acids (omega-3-PUFA) are known to ameliorate several metabolic risk factors for cardiovascular disease, and an association between elevated peripheral levels of endogenous ligands of cannabinoid receptors (endocannabinoids) and the metabolic syndrome has been reported. We investigated the dose-dependent effects of dietary omega-3-PUFA supplementation, given as krill oil (KO), on metabolic parameters in high fat diet (HFD)-fed mice and, in parallel, on the levels, in inguinal and epididymal adipose tissue (AT), liver, gastrocnemius muscle, kidneys and heart, of: 1) the endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), 2) two anandamide congeners which activate PPARalpha but not cannabinoid receptors, N-oleoylethanolamine (OEA) and N-palmitoylethanolamine (PEA), and 3) the direct biosynthetic precursors of these compounds. Methods: Lipids were identified and quantified using liquid chromatography coupled to atmospheric pressure chemical ionization single quadrupole mass spectrometry (LC-APCI- MS) or high resolution ion trap-time of flight mass spectrometry (LC-IT-ToF-MS).

Eight-week HFD increased endocannabinoid levels in all tissues except the liver and epididymal AT, and KO reduced anandamide and/or 2-AG levels in all tissues but not in the liver, usually in a dose-dependent manner. Levels of endocannabinoid precursors were also generally down-regulated, indicating that KO affects levels of endocannabinoids in part by reducing the availability of their biosynthetic precursors. Usually smaller effects were found of KO on OEA and PEA levels. Conclusions: Our data suggest that KO may promote therapeutic benefit by reducing endocannabinoid precursor availability and hence endocannabinoid biosynthesis.
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Thursday, July 21, 2011

Coffee and Tea Drinkers Less Likely to Carry MRSA

People who drink hot tea or coffee are less likely to carry the superbug known as methicillin-resistant Staphylococcus aureus (MRSA) in their noses, researchers found.

Drinking either beverage was associated with about a 50 percent relative reduction in the odds of nasal MRSA carriage, and drinking both was associated with a 67 percent reduction, according to Dr. Eric Matheson of the Medical University of South Carolina in Charleston and colleagues.

The findings, reported in the July/August issue of Annals of Family Medicine, "raise the possibility of a promising new method to decrease MRSA nasal carriage that is safe, inexpensive, and easily accessible," they wrote.

The clinical importance of the finding is not entirely clear, however, as the relationship between nasal MRSA carriage and the chances of systemic infection has not been resolved, they added.

Previous studies have shown that tea and coffee have antimicrobial properties when applied topically, and to find out whether drinking the beverages had systemic effects the researchers turned to the 2003-2004 National Health and Nutrition Examination Survey (NHANES).

The analysis included 5,555 individuals ages 2 and older, representing 182.1 million people. About half (48.6 percent) reported consuming hot tea over the past month and 60.8 percent reported drinking coffee over the past month.

Overall, 1.4 percent of the participants carried MRSA in their noses.

After adjustment for age, race, sex, poverty status, current health status, hospitalization in the past 12 months, and use of antibiotics in the past month, there were lower odds of nasal MRSA carriage among individuals who drank any amount of hot tea, coffee or both compared with those who drank none.

A separate analysis of just the adult participants provided similar results.

Consumption of iced tea, however, was not associated with nasal MRSA carriage. The reason is unclear, but it could be that iced tea has lower levels of polyphenolic compounds than hot tea, or that the volatile antimicrobial compounds in coffee and tea reach the nose in vapor form, according to the researchers.

Although the study -- cross-sectional in design -- could not establish a causal relationship between drinking coffee and tea and nasal MRSA carriage, there are some possible mechanisms to explain the finding.

"In the case of coffee, particular attention has focused on the potential antibacterial properties of trigonelline, glyoxal, methylglyoxal, and diacetyl," Matheson and colleagues wrote. "For tea, attention has focused on the antimicrobial properties of tannic acid and catechins."

In addition, they wrote, drinking both coffee and tea decrease iron absorption, which could affect the growth of S. aureus.

The authors acknowledged that the study was limited by the exclusion of some individuals because of missing data and the inability to determine when the participants last drank coffee or tea.

They noted that the study could not address the larger question of whether nasal MRSA carriage is associated with systemic infection.

"Given this debate, the benefits of any treatment for MRSA nasal carriage should be carefully balanced against the risk," they wrote.
People who drink hot tea or coffee are less likely to carry the superbug known as methicillin-resistant Staphylococcus aureus (MRSA) in their noses, researchers found.

Drinking either beverage was associated with about a 50 percent relative reduction in the odds of nasal MRSA carriage, and drinking both was associated with a 67 percent reduction, according to Dr. Eric Matheson of the Medical University of South Carolina in Charleston and colleagues.

The findings, reported in the July/August issue of Annals of Family Medicine, "raise the possibility of a promising new method to decrease MRSA nasal carriage that is safe, inexpensive, and easily accessible," they wrote.

The clinical importance of the finding is not entirely clear, however, as the relationship between nasal MRSA carriage and the chances of systemic infection has not been resolved, they added.

Previous studies have shown that tea and coffee have antimicrobial properties when applied topically, and to find out whether drinking the beverages had systemic effects the researchers turned to the 2003-2004 National Health and Nutrition Examination Survey (NHANES).

The analysis included 5,555 individuals ages 2 and older, representing 182.1 million people. About half (48.6 percent) reported consuming hot tea over the past month and 60.8 percent reported drinking coffee over the past month.

Overall, 1.4 percent of the participants carried MRSA in their noses.

After adjustment for age, race, sex, poverty status, current health status, hospitalization in the past 12 months, and use of antibiotics in the past month, there were lower odds of nasal MRSA carriage among individuals who drank any amount of hot tea, coffee or both compared with those who drank none.

A separate analysis of just the adult participants provided similar results.

Consumption of iced tea, however, was not associated with nasal MRSA carriage. The reason is unclear, but it could be that iced tea has lower levels of polyphenolic compounds than hot tea, or that the volatile antimicrobial compounds in coffee and tea reach the nose in vapor form, according to the researchers.

Although the study -- cross-sectional in design -- could not establish a causal relationship between drinking coffee and tea and nasal MRSA carriage, there are some possible mechanisms to explain the finding.

"In the case of coffee, particular attention has focused on the potential antibacterial properties of trigonelline, glyoxal, methylglyoxal, and diacetyl," Matheson and colleagues wrote. "For tea, attention has focused on the antimicrobial properties of tannic acid and catechins."

In addition, they wrote, drinking both coffee and tea decrease iron absorption, which could affect the growth of S. aureus.

The authors acknowledged that the study was limited by the exclusion of some individuals because of missing data and the inability to determine when the participants last drank coffee or tea.

They noted that the study could not address the larger question of whether nasal MRSA carriage is associated with systemic infection.

"Given this debate, the benefits of any treatment for MRSA nasal carriage should be carefully balanced against the risk," they wrote.
Read More


Eggs' Antioxidant Properties May Help Prevent Heart Disease and Cancer, Study Suggests

While eggs are well known to be an excellent source of proteins, lipids, vitamins and minerals, researchers at the University of Alberta recently discovered they also contain antioxidant properties, which helps in the prevention of cardiovascular disease and cancer.

Jianping Wu, Andreas Schieber and graduate students Chamila Nimalaratne and Daise Lopes-Lutz of the U of A Department of Agricultural Food and Nutritional Science examined egg yolks produced by hens fed typical diets of either primarily wheat or corn. They found the yolks contained two amino acids, tryptophan and tyrosine, which have high antioxidant properties.

After analyzing the properties, the researchers determined that two egg yolks in their raw state have almost twice as many antioxidant properties as an apple and about the same as half a serving (25 grams) of cranberries.

However, when the eggs were fried or boiled, antioxidant properties were reduced by about half, and a little more than half if the eggs were cooked in a microwave.

"It's a big reduction but it still leaves eggs equal to apples in their antioxidant value," said Wu.

The findings were published in the peer-reviewed journal Food Chemistry.

The discovery of these two amino acids, while important, may only signify the beginning of finding antioxidant properties in egg yolks, said Wu, an associate professor of agricultural, food and nutritional science.

"Ultimately, we're trying to map antioxidants in egg yolks so we have to look at all of the properties in the yolks that could contain antioxidants, as well as how the eggs are ingested," said Wu, adding that he and his team will examine the other type of antioxidant already known to be in eggs, carotenoids, the yellow pigment in egg yolk, as well as peptides.

In previous research, Wu found that egg proteins were converted by enzymes in the stomach and small intestines and produced peptides that act the same way as ACE inhibitors, prescriptions drugs that are used to lower high blood pressure.

That finding defied common wisdom and contradicted the public perception that eggs increased high blood pressure because of their high cholesterol content. Additional research by Wu suggests the peptides can be formulated to help prevent and treat hypertension.

Wu is convinced the peptides also have some antioxidant properties, which leads him to suggest that when he completes the next step in his research, the result will likely be that eggs have more antioxidant properties than we currently know.
While eggs are well known to be an excellent source of proteins, lipids, vitamins and minerals, researchers at the University of Alberta recently discovered they also contain antioxidant properties, which helps in the prevention of cardiovascular disease and cancer.

Jianping Wu, Andreas Schieber and graduate students Chamila Nimalaratne and Daise Lopes-Lutz of the U of A Department of Agricultural Food and Nutritional Science examined egg yolks produced by hens fed typical diets of either primarily wheat or corn. They found the yolks contained two amino acids, tryptophan and tyrosine, which have high antioxidant properties.

After analyzing the properties, the researchers determined that two egg yolks in their raw state have almost twice as many antioxidant properties as an apple and about the same as half a serving (25 grams) of cranberries.

However, when the eggs were fried or boiled, antioxidant properties were reduced by about half, and a little more than half if the eggs were cooked in a microwave.

"It's a big reduction but it still leaves eggs equal to apples in their antioxidant value," said Wu.

The findings were published in the peer-reviewed journal Food Chemistry.

The discovery of these two amino acids, while important, may only signify the beginning of finding antioxidant properties in egg yolks, said Wu, an associate professor of agricultural, food and nutritional science.

"Ultimately, we're trying to map antioxidants in egg yolks so we have to look at all of the properties in the yolks that could contain antioxidants, as well as how the eggs are ingested," said Wu, adding that he and his team will examine the other type of antioxidant already known to be in eggs, carotenoids, the yellow pigment in egg yolk, as well as peptides.

In previous research, Wu found that egg proteins were converted by enzymes in the stomach and small intestines and produced peptides that act the same way as ACE inhibitors, prescriptions drugs that are used to lower high blood pressure.

That finding defied common wisdom and contradicted the public perception that eggs increased high blood pressure because of their high cholesterol content. Additional research by Wu suggests the peptides can be formulated to help prevent and treat hypertension.

Wu is convinced the peptides also have some antioxidant properties, which leads him to suggest that when he completes the next step in his research, the result will likely be that eggs have more antioxidant properties than we currently know.
Read More


How Bright Promise in Cancer Testing Fell Apart

When Juliet Jacobs found out she had lung cancer, she was terrified, but realized that her hope lay in getting the best treatment medicine could offer. So she got a second opinion, then a third. In February of 2010, she ended up at Duke University, where she entered a research study whose promise seemed stunning.

Doctors would assess her tumor cells, looking for gene patterns that would determine which drugs would best attack her particular cancer. She would not waste precious time with ineffective drugs or trial-and-error treatment. The Duke program — considered a breakthrough at the time — was the first fruit of the new genomics, a way of letting a cancer cell’s own genes reveal the cancer’s weaknesses.

But the research at Duke turned out to be wrong. Its gene-based tests proved worthless, and the research behind them was discredited. Ms. Jacobs died a few months after treatment, and her husband and other patients’ relatives have retained lawyers.

The episode is a stark illustration of serious problems in a field in which the medical community has placed great hope: using patterns from large groups of genes or other molecules to improve the detection and treatment of cancer. Companies have been formed and products have been introduced that claim to use genetics in this way, but assertions have turned out to be unfounded. While researchers agree there is great promise in this science, it has yet to yield many reliable methods for diagnosing cancer or identifying the best treatment.

Instead, as patients and their doctors try to make critical decisions about serious illnesses, they may be getting worthless information that is based on bad science. The scientific world is concerned enough that two prominent groups, the National Cancer Institute and the Institute of Medicine, have begun examining the Duke case; they hope to find new ways to evaluate claims based on emerging and complex analyses of patterns of genes and other molecules.

So far, the Food and Drug Administration “has generally not enforced” its regulation of tests created by individual labs because, until recently, such tests were relatively simple and relied heavily on the expertise of a particular doctor, said Erica Jefferson, a spokeswoman for the agency. But now, with labs offering more complex tests on a large scale, the F.D.A. is taking a new look at enforcement.

Dr. Scott Ramsey, director of cancer outcomes research at the Fred Hutchinson Cancer Center in Seattle, says there is already “a mini-gold rush” of companies trying to market tests based on the new techniques, at a time when good science has not caught up with the financial push. “That’s the scariest part of all,” Dr. Ramsey said.

Doctors say the heart of the problem is the intricacy of the analyses in this emerging field and the difficulty in finding errors. Even well-respected scientists often “oversee a machine they do not understand and cannot supervise directly” because each segment of the research requires different areas of expertise, said Dr. Lajos Pusztai, a breast cancer researcher at M. D. Anderson Cancer Center at the University of Texas. As a senior scientist, he added, “It’s true for me, too.”

The Duke case came right after two other claims that gave medical researchers pause. Like the Duke case, they used complex analyses to detect patterns of genes or cell proteins. But these were tests that were supposed to find ovarian cancer in patients’ blood. One, OvaSure, was developed by a Yale scientist, Dr. Gil G. Mor, licensed by the university and sold to patients before it was found to be useless.

The other, OvaCheck, was developed by a company, Correlogic, with contributions from scientists from the National Cancer Institute and the Food and Drug Administration. Major commercial labs licensed it and were about to start using it before two statisticians from M. D. Anderson discovered and publicized its faults.

The Duke saga began when a prestigious journal, Nature Medicine, published a paper on Nov. 6, 2006, by Dr. Anil Potti, a cancer researcher at Duke University Medical Center; Joseph R. Nevins, a senior scientist there; and their colleagues. They wrote about genomic tests they developed that looked at the molecular traits of a cancerous tumor and figured out which chemotherapy would work best.

Other groups of cancer researchers had been trying to do the same thing.

“Our group was despondent to get beaten out,” said Dr. John Minna, a lung cancer researcher at the University of Texas Southwestern Medical Center. But Dr. Minna rallied; at the very least, he thought, he would make use of this incredible discovery to select drugs for lung cancer patients.

First, though, he asked two statisticians at M. D. Anderson, Keith Baggerly and Kevin Coombes, to check the work. Several other doctors approached them with the same request.

Dr. Baggerly and Dr. Coombes found errors almost immediately. Some seemed careless — moving a row or a column over by one in a giant spreadsheet — while others seemed inexplicable. The Duke team shrugged them off as “clerical errors.”

And the Duke researchers continued to publish papers on their genomic signatures in prestigious journals. Meanwhile, they started three trials using the work to decide which drugs to give patients.

Dr. Baggerly and Dr. Coombes tried to sound an alarm. They got the attention of the National Cancer Institute, whose own investigators wanted to use the Duke system in a clinical trial but were dissuaded by the criticisms. Finally, they published their analysis in The Annals of Applied Statistics, a journal that medical scientists rarely read.

The situation finally grabbed the cancer world’s attention last July, not because of the efforts of Dr. Baggerly and Dr. Coombes, but because a trade publication, The Cancer Letter, reported that the lead researcher, Dr. Potti, had falsified parts of his résumé. He claimed, among other things, that he had been a Rhodes scholar.

“It took that to make people sit up and take notice,” said Dr. Steven Goodman, professor of oncology, pediatrics, epidemiology and biostatistics at Johns Hopkins University.

In the end, four gene signature papers were retracted. Duke shut down three trials using the results. Dr. Potti resigned from Duke. He declined to be interviewed for this article. His collaborator and mentor, Dr. Nevins, no longer directs one of Duke’s genomics centers.

The cancer world is reeling.

The Duke researchers had even set up a company — now disbanded — and planned to sell their test to determine cancer treatments. Duke cancer patients and their families, including Mrs. Jacobs’s husband, Walter Jacobs, say they feel angry and betrayed. And medical researchers see the story as a call to action. With such huge data sets and complicated analyses, researchers can no longer trust their hunches that a result does — or does not — make sense.
When Juliet Jacobs found out she had lung cancer, she was terrified, but realized that her hope lay in getting the best treatment medicine could offer. So she got a second opinion, then a third. In February of 2010, she ended up at Duke University, where she entered a research study whose promise seemed stunning.

Doctors would assess her tumor cells, looking for gene patterns that would determine which drugs would best attack her particular cancer. She would not waste precious time with ineffective drugs or trial-and-error treatment. The Duke program — considered a breakthrough at the time — was the first fruit of the new genomics, a way of letting a cancer cell’s own genes reveal the cancer’s weaknesses.

But the research at Duke turned out to be wrong. Its gene-based tests proved worthless, and the research behind them was discredited. Ms. Jacobs died a few months after treatment, and her husband and other patients’ relatives have retained lawyers.

The episode is a stark illustration of serious problems in a field in which the medical community has placed great hope: using patterns from large groups of genes or other molecules to improve the detection and treatment of cancer. Companies have been formed and products have been introduced that claim to use genetics in this way, but assertions have turned out to be unfounded. While researchers agree there is great promise in this science, it has yet to yield many reliable methods for diagnosing cancer or identifying the best treatment.

Instead, as patients and their doctors try to make critical decisions about serious illnesses, they may be getting worthless information that is based on bad science. The scientific world is concerned enough that two prominent groups, the National Cancer Institute and the Institute of Medicine, have begun examining the Duke case; they hope to find new ways to evaluate claims based on emerging and complex analyses of patterns of genes and other molecules.

So far, the Food and Drug Administration “has generally not enforced” its regulation of tests created by individual labs because, until recently, such tests were relatively simple and relied heavily on the expertise of a particular doctor, said Erica Jefferson, a spokeswoman for the agency. But now, with labs offering more complex tests on a large scale, the F.D.A. is taking a new look at enforcement.

Dr. Scott Ramsey, director of cancer outcomes research at the Fred Hutchinson Cancer Center in Seattle, says there is already “a mini-gold rush” of companies trying to market tests based on the new techniques, at a time when good science has not caught up with the financial push. “That’s the scariest part of all,” Dr. Ramsey said.

Doctors say the heart of the problem is the intricacy of the analyses in this emerging field and the difficulty in finding errors. Even well-respected scientists often “oversee a machine they do not understand and cannot supervise directly” because each segment of the research requires different areas of expertise, said Dr. Lajos Pusztai, a breast cancer researcher at M. D. Anderson Cancer Center at the University of Texas. As a senior scientist, he added, “It’s true for me, too.”

The Duke case came right after two other claims that gave medical researchers pause. Like the Duke case, they used complex analyses to detect patterns of genes or cell proteins. But these were tests that were supposed to find ovarian cancer in patients’ blood. One, OvaSure, was developed by a Yale scientist, Dr. Gil G. Mor, licensed by the university and sold to patients before it was found to be useless.

The other, OvaCheck, was developed by a company, Correlogic, with contributions from scientists from the National Cancer Institute and the Food and Drug Administration. Major commercial labs licensed it and were about to start using it before two statisticians from M. D. Anderson discovered and publicized its faults.

The Duke saga began when a prestigious journal, Nature Medicine, published a paper on Nov. 6, 2006, by Dr. Anil Potti, a cancer researcher at Duke University Medical Center; Joseph R. Nevins, a senior scientist there; and their colleagues. They wrote about genomic tests they developed that looked at the molecular traits of a cancerous tumor and figured out which chemotherapy would work best.

Other groups of cancer researchers had been trying to do the same thing.

“Our group was despondent to get beaten out,” said Dr. John Minna, a lung cancer researcher at the University of Texas Southwestern Medical Center. But Dr. Minna rallied; at the very least, he thought, he would make use of this incredible discovery to select drugs for lung cancer patients.

First, though, he asked two statisticians at M. D. Anderson, Keith Baggerly and Kevin Coombes, to check the work. Several other doctors approached them with the same request.

Dr. Baggerly and Dr. Coombes found errors almost immediately. Some seemed careless — moving a row or a column over by one in a giant spreadsheet — while others seemed inexplicable. The Duke team shrugged them off as “clerical errors.”

And the Duke researchers continued to publish papers on their genomic signatures in prestigious journals. Meanwhile, they started three trials using the work to decide which drugs to give patients.

Dr. Baggerly and Dr. Coombes tried to sound an alarm. They got the attention of the National Cancer Institute, whose own investigators wanted to use the Duke system in a clinical trial but were dissuaded by the criticisms. Finally, they published their analysis in The Annals of Applied Statistics, a journal that medical scientists rarely read.

The situation finally grabbed the cancer world’s attention last July, not because of the efforts of Dr. Baggerly and Dr. Coombes, but because a trade publication, The Cancer Letter, reported that the lead researcher, Dr. Potti, had falsified parts of his résumé. He claimed, among other things, that he had been a Rhodes scholar.

“It took that to make people sit up and take notice,” said Dr. Steven Goodman, professor of oncology, pediatrics, epidemiology and biostatistics at Johns Hopkins University.

In the end, four gene signature papers were retracted. Duke shut down three trials using the results. Dr. Potti resigned from Duke. He declined to be interviewed for this article. His collaborator and mentor, Dr. Nevins, no longer directs one of Duke’s genomics centers.

The cancer world is reeling.

The Duke researchers had even set up a company — now disbanded — and planned to sell their test to determine cancer treatments. Duke cancer patients and their families, including Mrs. Jacobs’s husband, Walter Jacobs, say they feel angry and betrayed. And medical researchers see the story as a call to action. With such huge data sets and complicated analyses, researchers can no longer trust their hunches that a result does — or does not — make sense.
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